NEWS
author hoelzl
Tue, 29 Mar 2011 14:27:44 +0200
changeset 43020 7e6f4ca198bb
parent 42938 3eba96ff3d3e
child 43031 43cba90b080f
permissions -rw-r--r--
NEWS
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Theory loader: source files are identified by content via SHA1
    10 digests.  Discontinued former path/modtime identification and optional
    11 ISABELLE_FILE_IDENT plugin scripts.
    12 
    13 * Parallelization of nested Isar proofs is subject to
    14 Goal.parallel_proofs_threshold (default 100).  See also isabelle
    15 usedir option -Q.
    16 
    17 * Discontinued support for Poly/ML 5.2, which was the last version
    18 without proper multithreading and TimeLimit implementation.
    19 
    20 * Discontinued old lib/scripts/polyml-platform, which has been
    21 obsolete since Isabelle2009-2.
    22 
    23 * Theory loader: source files are exclusively located via the master
    24 directory of each theory node (where the .thy file itself resides).
    25 The global load path (such as src/HOL/Library) is has been
    26 discontinued.  INCOMPATIBILITY.
    27 
    28 * Various optional external tools are referenced more robustly and
    29 uniformly by explicit Isabelle settings as follows:
    30 
    31   ISABELLE_CSDP   (formerly CSDP_EXE)
    32   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
    33   ISABELLE_OCAML  (formerly EXEC_OCAML)
    34   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
    35   ISABELLE_YAP    (formerly EXEC_YAP)
    36 
    37 Note that automated detection from the file-system or search path has
    38 been discontinued.  INCOMPATIBILITY.
    39 
    40 
    41 *** HOL ***
    42 
    43 * Nitpick:
    44   - Added "need" and "total_consts" options.
    45   - Reintroduced "show_skolems" option by popular demand.
    46   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    47     INCOMPATIBILITY.
    48 
    49 * Sledgehammer:
    50   - sledgehammer available_provers ~> sledgehammer supported_provers
    51     INCOMPATIBILITY.
    52 
    53 * "try":
    54   - Added "simp:", "intro:", and "elim:" options.
    55 
    56 * Function package: discontinued option "tailrec".
    57 INCOMPATIBILITY. Use partial_function instead.
    58 
    59 * HOL-Probability:
    60   - Caratheodory's extension lemma is now proved for ring_of_sets.
    61   - Infinite products of probability measures are now available.
    62   - Use extended reals instead of positive extended reals.
    63     INCOMPATIBILITY.
    64 
    65 *** Document preparation ***
    66 
    67 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
    68 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
    69 
    70 
    71 *** ML ***
    72 
    73 * Structure Timing provides various operations for timing; supersedes
    74 former start_timing/end_timing etc.
    75 
    76 * Path.print is the official way to show file-system paths to users
    77 (including quotes etc.).
    78 
    79 * Inner syntax: identifiers in parse trees of generic categories
    80 "logic", "aprop", "idt" etc. carry position information (disguised as
    81 type constraints).  Occasional INCOMPATIBILITY with non-compliant
    82 translations that choke on unexpected type constraints.  Positions can
    83 be stripped in ML translations via Syntax.strip_positions /
    84 Syntax.strip_positions_ast, or via the syntax constant
    85 "_strip_positions" within parse trees.  As last resort, positions can
    86 be disabled via the configuration option Syntax.positions, which is
    87 called "syntax_positions" in Isar attribute syntax.
    88 
    89 
    90 
    91 New in Isabelle2011 (January 2011)
    92 ----------------------------------
    93 
    94 *** General ***
    95 
    96 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
    97 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
    98 useful tooltips and hyperlinks produced from its static analysis.  The
    99 bundled component provides an executable Isabelle tool that can be run
   100 like this:
   101 
   102   Isabelle2011/bin/isabelle jedit
   103 
   104 * Significantly improved Isabelle/Isar implementation manual.
   105 
   106 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   107 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   108 while the default heap location within that directory lacks that extra
   109 suffix.  This isolates multiple Isabelle installations from each
   110 other, avoiding problems with old settings in new versions.
   111 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   112 
   113 * Source files are always encoded as UTF-8, instead of old-fashioned
   114 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   115 the following package declarations:
   116 
   117   \usepackage[utf8]{inputenc}
   118   \usepackage{textcomp}
   119 
   120 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   121 a Unicode character is treated as a single symbol, not a sequence of
   122 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   123 contain symbols without further backslash escapes, Unicode can now be
   124 used here as well.  Recall that Symbol.explode in ML provides a
   125 consistent view on symbols, while raw explode (or String.explode)
   126 merely give a byte-oriented representation.
   127 
   128 * Theory loader: source files are primarily located via the master
   129 directory of each theory node (where the .thy file itself resides).
   130 The global load path is still partially available as legacy feature.
   131 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   132 explicit paths, relatively to the theory.
   133 
   134 * Special treatment of ML file names has been discontinued.
   135 Historically, optional extensions .ML or .sml were added on demand --
   136 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   137 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   138 
   139 * Various options that affect pretty printing etc. are now properly
   140 handled within the context via configuration options, instead of
   141 unsynchronized references or print modes.  There are both ML Config.T
   142 entities and Isar declaration attributes to access these.
   143 
   144   ML (Config.T)                 Isar (attribute)
   145 
   146   eta_contract                  eta_contract
   147   show_brackets                 show_brackets
   148   show_sorts                    show_sorts
   149   show_types                    show_types
   150   show_question_marks           show_question_marks
   151   show_consts                   show_consts
   152   show_abbrevs                  show_abbrevs
   153 
   154   Syntax.ast_trace              syntax_ast_trace
   155   Syntax.ast_stat               syntax_ast_stat
   156   Syntax.ambiguity_level        syntax_ambiguity_level
   157 
   158   Goal_Display.goals_limit      goals_limit
   159   Goal_Display.show_main_goal   show_main_goal
   160 
   161   Method.rule_trace             rule_trace
   162 
   163   Thy_Output.display            thy_output_display
   164   Thy_Output.quotes             thy_output_quotes
   165   Thy_Output.indent             thy_output_indent
   166   Thy_Output.source             thy_output_source
   167   Thy_Output.break              thy_output_break
   168 
   169 Note that corresponding "..._default" references in ML may only be
   170 changed globally at the ROOT session setup, but *not* within a theory.
   171 The option "show_abbrevs" supersedes the former print mode
   172 "no_abbrevs" with inverted meaning.
   173 
   174 * More systematic naming of some configuration options.
   175 INCOMPATIBILITY.
   176 
   177   trace_simp  ~>  simp_trace
   178   debug_simp  ~>  simp_debug
   179 
   180 * Support for real valued configuration options, using simplistic
   181 floating-point notation that coincides with the inner syntax for
   182 float_token.
   183 
   184 * Support for real valued preferences (with approximative PGIP type):
   185 front-ends need to accept "pgint" values in float notation.
   186 INCOMPATIBILITY.
   187 
   188 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   189 DejaVu Sans.
   190 
   191 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   192 
   193 
   194 *** Pure ***
   195 
   196 * Command 'type_synonym' (with single argument) replaces somewhat
   197 outdated 'types', which is still available as legacy feature for some
   198 time.
   199 
   200 * Command 'nonterminal' (with 'and' separated list of arguments)
   201 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   202 
   203 * Command 'notepad' replaces former 'example_proof' for
   204 experimentation in Isar without any result.  INCOMPATIBILITY.
   205 
   206 * Locale interpretation commands 'interpret' and 'sublocale' accept
   207 lists of equations to map definitions in a locale to appropriate
   208 entities in the context of the interpretation.  The 'interpretation'
   209 command already provided this functionality.
   210 
   211 * Diagnostic command 'print_dependencies' prints the locale instances
   212 that would be activated if the specified expression was interpreted in
   213 the current context.  Variant "print_dependencies!" assumes a context
   214 without interpretations.
   215 
   216 * Diagnostic command 'print_interps' prints interpretations in proofs
   217 in addition to interpretations in theories.
   218 
   219 * Discontinued obsolete 'global' and 'local' commands to manipulate
   220 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   221 Sign.root_path and Sign.local_path may be applied directly where this
   222 feature is still required for historical reasons.
   223 
   224 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   225 'definition' instead.
   226 
   227 * The "prems" fact, which refers to the accidental collection of
   228 foundational premises in the context, is now explicitly marked as
   229 legacy feature and will be discontinued soon.  Consider using "assms"
   230 of the head statement or reference facts by explicit names.
   231 
   232 * Document antiquotations @{class} and @{type} print classes and type
   233 constructors.
   234 
   235 * Document antiquotation @{file} checks file/directory entries within
   236 the local file system.
   237 
   238 
   239 *** HOL ***
   240 
   241 * Coercive subtyping: functions can be declared as coercions and type
   242 inference will add them as necessary upon input of a term.  Theory
   243 Complex_Main declares real :: nat => real and real :: int => real as
   244 coercions. A coercion function f is declared like this:
   245 
   246   declare [[coercion f]]
   247 
   248 To lift coercions through type constructors (e.g. from nat => real to
   249 nat list => real list), map functions can be declared, e.g.
   250 
   251   declare [[coercion_map map]]
   252 
   253 Currently coercion inference is activated only in theories including
   254 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   255 the configuration option "coercion_enabled", e.g. it can be enabled in
   256 other theories like this:
   257 
   258   declare [[coercion_enabled]]
   259 
   260 * Command 'partial_function' provides basic support for recursive
   261 function definitions over complete partial orders.  Concrete instances
   262 are provided for i) the option type, ii) tail recursion on arbitrary
   263 types, and iii) the heap monad of Imperative_HOL.  See
   264 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   265 for examples.
   266 
   267 * Function package: f.psimps rules are no longer implicitly declared
   268 as [simp].  INCOMPATIBILITY.
   269 
   270 * Datatype package: theorems generated for executable equality (class
   271 "eq") carry proper names and are treated as default code equations.
   272 
   273 * Inductive package: now offers command 'inductive_simps' to
   274 automatically derive instantiated and simplified equations for
   275 inductive predicates, similar to 'inductive_cases'.
   276 
   277 * Command 'enriched_type' allows to register properties of the
   278 functorial structure of types.
   279 
   280 * Improved infrastructure for term evaluation using code generator
   281 techniques, in particular static evaluation conversions.
   282 
   283 * Code generator: Scala (2.8 or higher) has been added to the target
   284 languages.
   285 
   286 * Code generator: globbing constant expressions "*" and "Theory.*"
   287 have been replaced by the more idiomatic "_" and "Theory._".
   288 INCOMPATIBILITY.
   289 
   290 * Code generator: export_code without explicit file declaration prints
   291 to standard output.  INCOMPATIBILITY.
   292 
   293 * Code generator: do not print function definitions for case
   294 combinators any longer.
   295 
   296 * Code generator: simplification with rules determined with
   297 src/Tools/Code/code_simp.ML and method "code_simp".
   298 
   299 * Code generator for records: more idiomatic representation of record
   300 types.  Warning: records are not covered by ancient SML code
   301 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   302 rep_datatype declaration helps to succeed then:
   303 
   304   record 'a foo = ...
   305   ...
   306   rep_datatype foo_ext ...
   307 
   308 * Records: logical foundation type for records does not carry a
   309 '_type' suffix any longer (obsolete due to authentic syntax).
   310 INCOMPATIBILITY.
   311 
   312 * Quickcheck now by default uses exhaustive testing instead of random
   313 testing.  Random testing can be invoked by "quickcheck [random]",
   314 exhaustive testing by "quickcheck [exhaustive]".
   315 
   316 * Quickcheck instantiates polymorphic types with small finite
   317 datatypes by default. This enables a simple execution mechanism to
   318 handle quantifiers and function equality over the finite datatypes.
   319 
   320 * Quickcheck random generator has been renamed from "code" to
   321 "random".  INCOMPATIBILITY.
   322 
   323 * Quickcheck now has a configurable time limit which is set to 30
   324 seconds by default. This can be changed by adding [timeout = n] to the
   325 quickcheck command. The time limit for Auto Quickcheck is still set
   326 independently.
   327 
   328 * Quickcheck in locales considers interpretations of that locale for
   329 counter example search.
   330 
   331 * Sledgehammer:
   332   - Added "smt" and "remote_smt" provers based on the "smt" proof
   333     method. See the Sledgehammer manual for details ("isabelle doc
   334     sledgehammer").
   335   - Renamed commands:
   336     sledgehammer atp_info ~> sledgehammer running_provers
   337     sledgehammer atp_kill ~> sledgehammer kill_provers
   338     sledgehammer available_atps ~> sledgehammer available_provers
   339     INCOMPATIBILITY.
   340   - Renamed options:
   341     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   342     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   343     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   344     (and "ms" and "min" are no longer supported)
   345     INCOMPATIBILITY.
   346 
   347 * Nitpick:
   348   - Renamed options:
   349     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   350     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   351     INCOMPATIBILITY.
   352   - Added support for partial quotient types.
   353   - Added local versions of the "Nitpick.register_xxx" functions.
   354   - Added "whack" option.
   355   - Allow registration of quotient types as codatatypes.
   356   - Improved "merge_type_vars" option to merge more types.
   357   - Removed unsound "fast_descrs" option.
   358   - Added custom symmetry breaking for datatypes, making it possible to reach
   359     higher cardinalities.
   360   - Prevent the expansion of too large definitions.
   361 
   362 * Proof methods "metis" and "meson" now have configuration options
   363 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   364 to diagnose these tools. E.g.
   365 
   366     using [[metis_trace = true]]
   367 
   368 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   369 manually as command 'solve_direct'.
   370 
   371 * The default SMT solver Z3 must be enabled explicitly (due to
   372 licensing issues) by setting the environment variable
   373 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   374 commercial applications, the SMT solver CVC3 is provided as fall-back;
   375 changing the SMT solver is done via the configuration option
   376 "smt_solver".
   377 
   378 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   379 i.e. "remote_cvc3" and "remote_z3".
   380 
   381 * Added basic SMT support for datatypes, records, and typedefs using
   382 the oracle mode (no proofs).  Direct support of pairs has been dropped
   383 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   384 support for a similar behavior).  Minor INCOMPATIBILITY.
   385 
   386 * Changed SMT configuration options:
   387   - Renamed:
   388     z3_proofs ~> smt_oracle (with inverted meaning)
   389     z3_trace_assms ~> smt_trace_used_facts
   390     INCOMPATIBILITY.
   391   - Added:
   392     smt_verbose
   393     smt_random_seed
   394     smt_datatypes
   395     smt_infer_triggers
   396     smt_monomorph_limit
   397     cvc3_options
   398     remote_cvc3_options
   399     remote_z3_options
   400     yices_options
   401 
   402 * Boogie output files (.b2i files) need to be declared in the theory
   403 header.
   404 
   405 * Simplification procedure "list_to_set_comprehension" rewrites list
   406 comprehensions applied to List.set to set comprehensions.  Occasional
   407 INCOMPATIBILITY, may be deactivated like this:
   408 
   409   declare [[simproc del: list_to_set_comprehension]]
   410 
   411 * Removed old version of primrec package.  INCOMPATIBILITY.
   412 
   413 * Removed simplifier congruence rule of "prod_case", as has for long
   414 been the case with "split".  INCOMPATIBILITY.
   415 
   416 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   417 
   418 * Removed [split_format ... and ... and ...] version of
   419 [split_format].  Potential INCOMPATIBILITY.
   420 
   421 * Predicate "sorted" now defined inductively, with nice induction
   422 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   423 
   424 * Constant "contents" renamed to "the_elem", to free the generic name
   425 contents for other uses.  INCOMPATIBILITY.
   426 
   427 * Renamed class eq and constant eq (for code generation) to class
   428 equal and constant equal, plus renaming of related facts and various
   429 tuning.  INCOMPATIBILITY.
   430 
   431 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   432 
   433 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   434 INCOMPATIBILITY.
   435 
   436 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   437 avoid confusion with finite sets.  INCOMPATIBILITY.
   438 
   439 * Abandoned locales equiv, congruent and congruent2 for equivalence
   440 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   441 for congruent(2)).
   442 
   443 * Some previously unqualified names have been qualified:
   444 
   445   types
   446     bool ~> HOL.bool
   447     nat ~> Nat.nat
   448 
   449   constants
   450     Trueprop ~> HOL.Trueprop
   451     True ~> HOL.True
   452     False ~> HOL.False
   453     op & ~> HOL.conj
   454     op | ~> HOL.disj
   455     op --> ~> HOL.implies
   456     op = ~> HOL.eq
   457     Not ~> HOL.Not
   458     The ~> HOL.The
   459     All ~> HOL.All
   460     Ex ~> HOL.Ex
   461     Ex1 ~> HOL.Ex1
   462     Let ~> HOL.Let
   463     If ~> HOL.If
   464     Ball ~> Set.Ball
   465     Bex ~> Set.Bex
   466     Suc ~> Nat.Suc
   467     Pair ~> Product_Type.Pair
   468     fst ~> Product_Type.fst
   469     snd ~> Product_Type.snd
   470     curry ~> Product_Type.curry
   471     op : ~> Set.member
   472     Collect ~> Set.Collect
   473 
   474 INCOMPATIBILITY.
   475 
   476 * More canonical naming convention for some fundamental definitions:
   477 
   478     bot_bool_eq ~> bot_bool_def
   479     top_bool_eq ~> top_bool_def
   480     inf_bool_eq ~> inf_bool_def
   481     sup_bool_eq ~> sup_bool_def
   482     bot_fun_eq  ~> bot_fun_def
   483     top_fun_eq  ~> top_fun_def
   484     inf_fun_eq  ~> inf_fun_def
   485     sup_fun_eq  ~> sup_fun_def
   486 
   487 INCOMPATIBILITY.
   488 
   489 * More stylized fact names:
   490 
   491   expand_fun_eq ~> fun_eq_iff
   492   expand_set_eq ~> set_eq_iff
   493   set_ext       ~> set_eqI
   494   nat_number    ~> eval_nat_numeral
   495 
   496 INCOMPATIBILITY.
   497 
   498 * Refactoring of code-generation specific operations in theory List:
   499 
   500   constants
   501     null ~> List.null
   502 
   503   facts
   504     mem_iff ~> member_def
   505     null_empty ~> null_def
   506 
   507 INCOMPATIBILITY.  Note that these were not supposed to be used
   508 regularly unless for striking reasons; their main purpose was code
   509 generation.
   510 
   511 Various operations from the Haskell prelude are used for generating
   512 Haskell code.
   513 
   514 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   515 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   516 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   517 
   518 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   519 "*" and "+" respectively.  INCOMPATIBILITY.
   520 
   521 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   522 "Sum_Type.Plus" instead.
   523 
   524 * Constant "split" has been merged with constant "prod_case"; names of
   525 ML functions, facts etc. involving split have been retained so far,
   526 though.  INCOMPATIBILITY.
   527 
   528 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   529 instead.  INCOMPATIBILITY.
   530 
   531 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   532 INCOMPATIBILITY.
   533 
   534 * Former theory Library/Enum is now part of the HOL-Main image.
   535 INCOMPATIBILITY: all constants of the Enum theory now have to be
   536 referred to by its qualified name.
   537 
   538   enum    ~>  Enum.enum
   539   nlists  ~>  Enum.nlists
   540   product ~>  Enum.product
   541 
   542 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   543 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   544 INCOMPATIBILITY.
   545 
   546 * Theory Library/SetsAndFunctions has been split into
   547 Library/Function_Algebras and Library/Set_Algebras; canonical names
   548 for instance definitions for functions; various improvements.
   549 INCOMPATIBILITY.
   550 
   551 * Theory Library/Multiset provides stable quicksort implementation of
   552 sort_key.
   553 
   554 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   555 INCOMPATIBILITY.
   556 
   557 * Session Multivariate_Analysis: introduced a type class for euclidean
   558 space.  Most theorems are now stated in terms of euclidean spaces
   559 instead of finite cartesian products.
   560 
   561   types
   562     real ^ 'n ~>  'a::real_vector
   563               ~>  'a::euclidean_space
   564               ~>  'a::ordered_euclidean_space
   565         (depends on your needs)
   566 
   567   constants
   568      _ $ _        ~> _ $$ _
   569      \<chi> x. _  ~> \<chi>\<chi> x. _
   570      CARD('n)     ~> DIM('a)
   571 
   572 Also note that the indices are now natural numbers and not from some
   573 finite type. Finite cartesian products of euclidean spaces, products
   574 of euclidean spaces the real and complex numbers are instantiated to
   575 be euclidean_spaces.  INCOMPATIBILITY.
   576 
   577 * Session Probability: introduced pextreal as positive extended real
   578 numbers.  Use pextreal as value for measures.  Introduce the
   579 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   580 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   581 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   582 
   583 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   584 INCOMPATIBILITY.
   585 
   586 * Session SPARK (with image HOL-SPARK) provides commands to load and
   587 prove verification conditions generated by the SPARK Ada program
   588 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   589 
   590 
   591 *** HOL-Algebra ***
   592 
   593 * Theorems for additive ring operations (locale abelian_monoid and
   594 descendants) are generated by interpretation from their multiplicative
   595 counterparts.  Names (in particular theorem names) have the mandatory
   596 qualifier 'add'.  Previous theorem names are redeclared for
   597 compatibility.
   598 
   599 * Structure "int_ring" is now an abbreviation (previously a
   600 definition).  This fits more natural with advanced interpretations.
   601 
   602 
   603 *** HOLCF ***
   604 
   605 * The domain package now runs in definitional mode by default: The
   606 former command 'new_domain' is now called 'domain'.  To use the domain
   607 package in its original axiomatic mode, use 'domain (unsafe)'.
   608 INCOMPATIBILITY.
   609 
   610 * The new class "domain" is now the default sort.  Class "predomain"
   611 is an unpointed version of "domain". Theories can be updated by
   612 replacing sort annotations as shown below.  INCOMPATIBILITY.
   613 
   614   'a::type ~> 'a::countable
   615   'a::cpo  ~> 'a::predomain
   616   'a::pcpo ~> 'a::domain
   617 
   618 * The old type class "rep" has been superseded by class "domain".
   619 Accordingly, users of the definitional package must remove any
   620 "default_sort rep" declarations.  INCOMPATIBILITY.
   621 
   622 * The domain package (definitional mode) now supports unpointed
   623 predomain argument types, as long as they are marked 'lazy'. (Strict
   624 arguments must be in class "domain".) For example, the following
   625 domain definition now works:
   626 
   627   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   628 
   629 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   630 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   631 'a option, and 'a list.  Additionally, it configures fixrec and the
   632 domain package to work with these types.  For example:
   633 
   634   fixrec isInl :: "('a + 'b) u -> tr"
   635     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   636 
   637   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   638 
   639 * The "(permissive)" option of fixrec has been replaced with a
   640 per-equation "(unchecked)" option. See
   641 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   642 
   643 * The "bifinite" class no longer fixes a constant "approx"; the class
   644 now just asserts that such a function exists.  INCOMPATIBILITY.
   645 
   646 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   647 defines an embedding of type 'a defl into udom by default; instances
   648 of "bifinite" and "domain" classes are available in
   649 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   650 
   651 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   652 
   653 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   654 
   655 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   656 
   657 * The function "cprod_map" has been renamed to "prod_map".
   658 INCOMPATIBILITY.
   659 
   660 * The monadic bind operator on each powerdomain has new binder syntax
   661 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   662 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   663 
   664 * The infix syntax for binary union on each powerdomain has changed
   665 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   666 syntax.  INCOMPATIBILITY.
   667 
   668 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   669 still supported as an input translation.
   670 
   671 * Renamed some theorems (the original names are also still available).
   672 
   673   expand_fun_below   ~> fun_below_iff
   674   below_fun_ext      ~> fun_belowI
   675   expand_cfun_eq     ~> cfun_eq_iff
   676   ext_cfun           ~> cfun_eqI
   677   expand_cfun_below  ~> cfun_below_iff
   678   below_cfun_ext     ~> cfun_belowI
   679   cont2cont_Rep_CFun ~> cont2cont_APP
   680 
   681 * The Abs and Rep functions for various types have changed names.
   682 Related theorem names have also changed to match. INCOMPATIBILITY.
   683 
   684   Rep_CFun  ~> Rep_cfun
   685   Abs_CFun  ~> Abs_cfun
   686   Rep_Sprod ~> Rep_sprod
   687   Abs_Sprod ~> Abs_sprod
   688   Rep_Ssum  ~> Rep_ssum
   689   Abs_Ssum  ~> Abs_ssum
   690 
   691 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   692 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   693 
   694 * Various changes to bisimulation/coinduction with domain package:
   695 
   696   - Definitions of "bisim" constants no longer mention definedness.
   697   - With mutual recursion, "bisim" predicate is now curried.
   698   - With mutual recursion, each type gets a separate coind theorem.
   699   - Variable names in bisim_def and coinduct rules have changed.
   700 
   701 INCOMPATIBILITY.
   702 
   703 * Case combinators generated by the domain package for type "foo" are
   704 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   705 
   706 * Several theorems have been renamed to more accurately reflect the
   707 names of constants and types involved.  INCOMPATIBILITY.
   708 
   709   thelub_const    ~> lub_const
   710   lub_const       ~> is_lub_const
   711   thelubI         ~> lub_eqI
   712   is_lub_lub      ~> is_lubD2
   713   lubI            ~> is_lub_lub
   714   unique_lub      ~> is_lub_unique
   715   is_ub_lub       ~> is_lub_rangeD1
   716   lub_bin_chain   ~> is_lub_bin_chain
   717   lub_fun         ~> is_lub_fun
   718   thelub_fun      ~> lub_fun
   719   thelub_cfun     ~> lub_cfun
   720   thelub_Pair     ~> lub_Pair
   721   lub_cprod       ~> is_lub_prod
   722   thelub_cprod    ~> lub_prod
   723   minimal_cprod   ~> minimal_prod
   724   inst_cprod_pcpo ~> inst_prod_pcpo
   725   UU_I            ~> bottomI
   726   compact_UU      ~> compact_bottom
   727   deflation_UU    ~> deflation_bottom
   728   finite_deflation_UU ~> finite_deflation_bottom
   729 
   730 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   731 
   732   sq_ord_less_eq_trans ~> below_eq_trans
   733   sq_ord_eq_less_trans ~> eq_below_trans
   734   refl_less            ~> below_refl
   735   trans_less           ~> below_trans
   736   antisym_less         ~> below_antisym
   737   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   738   box_less             ~> box_below
   739   rev_trans_less       ~> rev_below_trans
   740   not_less2not_eq      ~> not_below2not_eq
   741   less_UU_iff          ~> below_UU_iff
   742   flat_less_iff        ~> flat_below_iff
   743   adm_less             ~> adm_below
   744   adm_not_less         ~> adm_not_below
   745   adm_compact_not_less ~> adm_compact_not_below
   746   less_fun_def         ~> below_fun_def
   747   expand_fun_less      ~> fun_below_iff
   748   less_fun_ext         ~> fun_belowI
   749   less_discr_def       ~> below_discr_def
   750   discr_less_eq        ~> discr_below_eq
   751   less_unit_def        ~> below_unit_def
   752   less_cprod_def       ~> below_prod_def
   753   prod_lessI           ~> prod_belowI
   754   Pair_less_iff        ~> Pair_below_iff
   755   fst_less_iff         ~> fst_below_iff
   756   snd_less_iff         ~> snd_below_iff
   757   expand_cfun_less     ~> cfun_below_iff
   758   less_cfun_ext        ~> cfun_belowI
   759   injection_less       ~> injection_below
   760   less_up_def          ~> below_up_def
   761   not_Iup_less         ~> not_Iup_below
   762   Iup_less             ~> Iup_below
   763   up_less              ~> up_below
   764   Def_inject_less_eq   ~> Def_below_Def
   765   Def_less_is_eq       ~> Def_below_iff
   766   spair_less_iff       ~> spair_below_iff
   767   less_sprod           ~> below_sprod
   768   spair_less           ~> spair_below
   769   sfst_less_iff        ~> sfst_below_iff
   770   ssnd_less_iff        ~> ssnd_below_iff
   771   fix_least_less       ~> fix_least_below
   772   dist_less_one        ~> dist_below_one
   773   less_ONE             ~> below_ONE
   774   ONE_less_iff         ~> ONE_below_iff
   775   less_sinlD           ~> below_sinlD
   776   less_sinrD           ~> below_sinrD
   777 
   778 
   779 *** FOL and ZF ***
   780 
   781 * All constant names are now qualified internally and use proper
   782 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   783 
   784 
   785 *** ML ***
   786 
   787 * Antiquotation @{assert} inlines a function bool -> unit that raises
   788 Fail if the argument is false.  Due to inlining the source position of
   789 failed assertions is included in the error output.
   790 
   791 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   792 text is in practice always evaluated with a stable theory checkpoint.
   793 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   794 
   795 * Antiquotation @{theory A} refers to theory A from the ancestry of
   796 the current context, not any accidental theory loader state as before.
   797 Potential INCOMPATIBILITY, subtle change in semantics.
   798 
   799 * Syntax.pretty_priority (default 0) configures the required priority
   800 of pretty-printed output and thus affects insertion of parentheses.
   801 
   802 * Syntax.default_root (default "any") configures the inner syntax
   803 category (nonterminal symbol) for parsing of terms.
   804 
   805 * Former exception Library.UnequalLengths now coincides with
   806 ListPair.UnequalLengths.
   807 
   808 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   809 main functionality is provided by structure Simplifier.
   810 
   811 * Renamed raw "explode" function to "raw_explode" to emphasize its
   812 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   813 almost all situations.
   814 
   815 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   816 See implementation manual for further details on exceptions in
   817 Isabelle/ML.
   818 
   819 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   820 meaning.
   821 
   822 * Renamed structure PureThy to Pure_Thy and moved most of its
   823 operations to structure Global_Theory, to emphasize that this is
   824 rarely-used global-only stuff.
   825 
   826 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   827 instead (or tracing for high-volume output).
   828 
   829 * Configuration option show_question_marks only affects regular pretty
   830 printing of types and terms, not raw Term.string_of_vname.
   831 
   832 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   833 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   834 @{thms} for most purposes.
   835 
   836 * ML structure Unsynchronized is never opened, not even in Isar
   837 interaction mode as before.  Old Unsynchronized.set etc. have been
   838 discontinued -- use plain := instead.  This should be *rare* anyway,
   839 since modern tools always work via official context data, notably
   840 configuration options.
   841 
   842 * Parallel and asynchronous execution requires special care concerning
   843 interrupts.  Structure Exn provides some convenience functions that
   844 avoid working directly with raw Interrupt.  User code must not absorb
   845 interrupts -- intermediate handling (for cleanup etc.) needs to be
   846 followed by re-raising of the original exception.  Another common
   847 source of mistakes are "handle _" patterns, which make the meaning of
   848 the program subject to physical effects of the environment.
   849 
   850 
   851 
   852 New in Isabelle2009-2 (June 2010)
   853 ---------------------------------
   854 
   855 *** General ***
   856 
   857 * Authentic syntax for *all* logical entities (type classes, type
   858 constructors, term constants): provides simple and robust
   859 correspondence between formal entities and concrete syntax.  Within
   860 the parse tree / AST representations, "constants" are decorated by
   861 their category (class, type, const) and spelled out explicitly with
   862 their full internal name.
   863 
   864 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   865 and translations (translation rules and translation functions in ML).
   866 Some hints on upgrading:
   867 
   868   - Many existing uses of 'syntax' and 'translations' can be replaced
   869     by more modern 'type_notation', 'notation' and 'abbreviation',
   870     which are independent of this issue.
   871 
   872   - 'translations' require markup within the AST; the term syntax
   873     provides the following special forms:
   874 
   875       CONST c   -- produces syntax version of constant c from context
   876       XCONST c  -- literally c, checked as constant from context
   877       c         -- literally c, if declared by 'syntax'
   878 
   879     Plain identifiers are treated as AST variables -- occasionally the
   880     system indicates accidental variables via the error "rhs contains
   881     extra variables".
   882 
   883     Type classes and type constructors are marked according to their
   884     concrete syntax.  Some old translations rules need to be written
   885     for the "type" category, using type constructor application
   886     instead of pseudo-term application of the default category
   887     "logic".
   888 
   889   - 'parse_translation' etc. in ML may use the following
   890     antiquotations:
   891 
   892       @{class_syntax c}   -- type class c within parse tree / AST
   893       @{term_syntax c}    -- type constructor c within parse tree / AST
   894       @{const_syntax c}   -- ML version of "CONST c" above
   895       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   896 
   897   - Literal types within 'typed_print_translations', i.e. those *not*
   898     represented as pseudo-terms are represented verbatim.  Use @{class
   899     c} or @{type_name c} here instead of the above syntax
   900     antiquotations.
   901 
   902 Note that old non-authentic syntax was based on unqualified base
   903 names, so all of the above "constant" names would coincide.  Recall
   904 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   905 diagnose syntax problems.
   906 
   907 * Type constructors admit general mixfix syntax, not just infix.
   908 
   909 * Concrete syntax may be attached to local entities without a proof
   910 body, too.  This works via regular mixfix annotations for 'fix',
   911 'def', 'obtain' etc. or via the explicit 'write' command, which is
   912 similar to the 'notation' command in theory specifications.
   913 
   914 * Discontinued unnamed infix syntax (legacy feature for many years) --
   915 need to specify constant name and syntax separately.  Internal ML
   916 datatype constructors have been renamed from InfixName to Infix etc.
   917 Minor INCOMPATIBILITY.
   918 
   919 * Schematic theorem statements need to be explicitly markup as such,
   920 via commands 'schematic_lemma', 'schematic_theorem',
   921 'schematic_corollary'.  Thus the relevance of the proof is made
   922 syntactically clear, which impacts performance in a parallel or
   923 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   924 
   925 * Use of cumulative prems via "!" in some proof methods has been
   926 discontinued (old legacy feature).
   927 
   928 * References 'trace_simp' and 'debug_simp' have been replaced by
   929 configuration options stored in the context. Enabling tracing (the
   930 case of debugging is similar) in proofs works via
   931 
   932   using [[trace_simp = true]]
   933 
   934 Tracing is then active for all invocations of the simplifier in
   935 subsequent goal refinement steps. Tracing may also still be enabled or
   936 disabled via the ProofGeneral settings menu.
   937 
   938 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   939 'hide_fact' replace the former 'hide' KIND command.  Minor
   940 INCOMPATIBILITY.
   941 
   942 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   943 more efficient than combinations with -q1 or -q2.
   944 
   945 
   946 *** Pure ***
   947 
   948 * Proofterms record type-class reasoning explicitly, using the
   949 "unconstrain" operation internally.  This eliminates all sort
   950 constraints from a theorem and proof, introducing explicit
   951 OFCLASS-premises.  On the proof term level, this operation is
   952 automatically applied at theorem boundaries, such that closed proofs
   953 are always free of sort constraints.  INCOMPATIBILITY for tools that
   954 inspect proof terms.
   955 
   956 * Local theory specifications may depend on extra type variables that
   957 are not present in the result type -- arguments TYPE('a) :: 'a itself
   958 are added internally.  For example:
   959 
   960   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   961 
   962 * Predicates of locales introduced by classes carry a mandatory
   963 "class" prefix.  INCOMPATIBILITY.
   964 
   965 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   966 
   967 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   968 'class' instead.
   969 
   970 * Command 'code_reflect' allows to incorporate generated ML code into
   971 runtime environment; replaces immature code_datatype antiquotation.
   972 INCOMPATIBILITY.
   973 
   974 * Code generator: simple concept for abstract datatypes obeying
   975 invariants.
   976 
   977 * Code generator: details of internal data cache have no impact on the
   978 user space functionality any longer.
   979 
   980 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   981 subgoals.  This is more appropriate for interpretations with 'where'.
   982 INCOMPATIBILITY.
   983 
   984 * Command 'example_proof' opens an empty proof body.  This allows to
   985 experiment with Isar, without producing any persistent result.
   986 
   987 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   988 within a local theory context, with explicit checking of the
   989 constructors involved (in contrast to the raw 'syntax' versions).
   990 
   991 * Commands 'types' and 'typedecl' now work within a local theory
   992 context -- without introducing dependencies on parameters or
   993 assumptions, which is not possible in Isabelle/Pure.
   994 
   995 * Command 'defaultsort' has been renamed to 'default_sort', it works
   996 within a local theory context.  Minor INCOMPATIBILITY.
   997 
   998 
   999 *** HOL ***
  1000 
  1001 * Command 'typedef' now works within a local theory context -- without
  1002 introducing dependencies on parameters or assumptions, which is not
  1003 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1004 contain multiple interpretations of local typedefs (with different
  1005 non-emptiness proofs), even in a global theory context.
  1006 
  1007 * New package for quotient types.  Commands 'quotient_type' and
  1008 'quotient_definition' may be used for defining types and constants by
  1009 quotient constructions.  An example is the type of integers created by
  1010 quotienting pairs of natural numbers:
  1011 
  1012   fun
  1013     intrel :: "(nat * nat) => (nat * nat) => bool"
  1014   where
  1015     "intrel (x, y) (u, v) = (x + v = u + y)"
  1016 
  1017   quotient_type int = "nat * nat" / intrel
  1018     by (auto simp add: equivp_def expand_fun_eq)
  1019 
  1020   quotient_definition
  1021     "0::int" is "(0::nat, 0::nat)"
  1022 
  1023 The method "lifting" can be used to lift of theorems from the
  1024 underlying "raw" type to the quotient type.  The example
  1025 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1026 construction and provides a reasoning infrastructure for finite sets.
  1027 
  1028 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1029 clash with new theory Quotient in Main HOL.
  1030 
  1031 * Moved the SMT binding into the main HOL session, eliminating
  1032 separate HOL-SMT session.
  1033 
  1034 * List membership infix mem operation is only an input abbreviation.
  1035 INCOMPATIBILITY.
  1036 
  1037 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1038 for future developements; former Library/Word.thy is still present in
  1039 the AFP entry RSAPPS.
  1040 
  1041 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1042 longer shadowed.  INCOMPATIBILITY.
  1043 
  1044 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1045 INCOMPATIBILITY.
  1046 
  1047 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1048 INCOMPATIBILITY.
  1049 
  1050 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1051 instead.  INCOMPATIBILITY.
  1052 
  1053 * Dropped several real-specific versions of lemmas about floor and
  1054 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1055 instead.  INCOMPATIBILITY.
  1056 
  1057   floor_number_of_eq         ~> floor_number_of
  1058   le_floor_eq_number_of      ~> number_of_le_floor
  1059   le_floor_eq_zero           ~> zero_le_floor
  1060   le_floor_eq_one            ~> one_le_floor
  1061   floor_less_eq_number_of    ~> floor_less_number_of
  1062   floor_less_eq_zero         ~> floor_less_zero
  1063   floor_less_eq_one          ~> floor_less_one
  1064   less_floor_eq_number_of    ~> number_of_less_floor
  1065   less_floor_eq_zero         ~> zero_less_floor
  1066   less_floor_eq_one          ~> one_less_floor
  1067   floor_le_eq_number_of      ~> floor_le_number_of
  1068   floor_le_eq_zero           ~> floor_le_zero
  1069   floor_le_eq_one            ~> floor_le_one
  1070   floor_subtract_number_of   ~> floor_diff_number_of
  1071   floor_subtract_one         ~> floor_diff_one
  1072   ceiling_number_of_eq       ~> ceiling_number_of
  1073   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1074   ceiling_le_zero_eq         ~> ceiling_le_zero
  1075   ceiling_le_eq_one          ~> ceiling_le_one
  1076   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1077   less_ceiling_eq_zero       ~> zero_less_ceiling
  1078   less_ceiling_eq_one        ~> one_less_ceiling
  1079   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1080   ceiling_less_eq_zero       ~> ceiling_less_zero
  1081   ceiling_less_eq_one        ~> ceiling_less_one
  1082   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1083   le_ceiling_eq_zero         ~> zero_le_ceiling
  1084   le_ceiling_eq_one          ~> one_le_ceiling
  1085   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1086   ceiling_subtract_one       ~> ceiling_diff_one
  1087 
  1088 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1089 application of the various fold combinators on finite sets.
  1090 
  1091 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1092 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1093 implementation.  INCOMPATIBILTY.
  1094 
  1095 * Theory Library/Coinductive_List has been removed -- superseded by
  1096 AFP/thys/Coinductive.
  1097 
  1098 * Theory PReal, including the type "preal" and related operations, has
  1099 been removed.  INCOMPATIBILITY.
  1100 
  1101 * Real: new development using Cauchy Sequences.
  1102 
  1103 * Split off theory "Big_Operators" containing setsum, setprod,
  1104 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1105 
  1106 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1107 "Int" etc.  INCOMPATIBILITY.
  1108 
  1109 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1110 
  1111 * New set of rules "ac_simps" provides combined assoc / commute
  1112 rewrites for all interpretations of the appropriate generic locales.
  1113 
  1114 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1115 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1116 appropriate and more consistent names suitable for name prefixes
  1117 within the HOL theories.  INCOMPATIBILITY.
  1118 
  1119 * Some generic constants have been put to appropriate theories:
  1120   - less_eq, less: Orderings
  1121   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1122   - inverse, divide: Rings
  1123 INCOMPATIBILITY.
  1124 
  1125 * More consistent naming of type classes involving orderings (and
  1126 lattices):
  1127 
  1128     lower_semilattice                   ~> semilattice_inf
  1129     upper_semilattice                   ~> semilattice_sup
  1130 
  1131     dense_linear_order                  ~> dense_linorder
  1132 
  1133     pordered_ab_group_add               ~> ordered_ab_group_add
  1134     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1135     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1136     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1137     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1138     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1139     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1140     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1141     pordered_comm_ring                  ~> ordered_comm_ring
  1142     pordered_comm_semiring              ~> ordered_comm_semiring
  1143     pordered_ring                       ~> ordered_ring
  1144     pordered_ring_abs                   ~> ordered_ring_abs
  1145     pordered_semiring                   ~> ordered_semiring
  1146 
  1147     ordered_ab_group_add                ~> linordered_ab_group_add
  1148     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1149     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1150     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1151     ordered_field                       ~> linordered_field
  1152     ordered_field_no_lb                 ~> linordered_field_no_lb
  1153     ordered_field_no_ub                 ~> linordered_field_no_ub
  1154     ordered_field_dense_linear_order    ~> dense_linordered_field
  1155     ordered_idom                        ~> linordered_idom
  1156     ordered_ring                        ~> linordered_ring
  1157     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1158     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1159     ordered_ring_strict                 ~> linordered_ring_strict
  1160     ordered_semidom                     ~> linordered_semidom
  1161     ordered_semiring                    ~> linordered_semiring
  1162     ordered_semiring_1                  ~> linordered_semiring_1
  1163     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1164     ordered_semiring_strict             ~> linordered_semiring_strict
  1165 
  1166   The following slightly odd type classes have been moved to a
  1167   separate theory Library/Lattice_Algebras:
  1168 
  1169     lordered_ab_group_add               ~> lattice_ab_group_add
  1170     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1171     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1172     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1173     lordered_ring                       ~> lattice_ring
  1174 
  1175 INCOMPATIBILITY.
  1176 
  1177 * Refined field classes:
  1178   - classes division_ring_inverse_zero, field_inverse_zero,
  1179     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1180     subsumes former division_by_zero class;
  1181   - numerous lemmas have been ported from field to division_ring.
  1182 INCOMPATIBILITY.
  1183 
  1184 * Refined algebra theorem collections:
  1185   - dropped theorem group group_simps, use algebra_simps instead;
  1186   - dropped theorem group ring_simps, use field_simps instead;
  1187   - proper theorem collection field_simps subsumes former theorem
  1188     groups field_eq_simps and field_simps;
  1189   - dropped lemma eq_minus_self_iff which is a duplicate for
  1190     equal_neg_zero.
  1191 INCOMPATIBILITY.
  1192 
  1193 * Theory Finite_Set and List: some lemmas have been generalized from
  1194 sets to lattices:
  1195 
  1196   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1197   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1198   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1199   union_Union_fold_union        ~> sup_Sup_fold_sup
  1200   Inter_fold_inter              ~> Inf_fold_inf
  1201   Union_fold_union              ~> Sup_fold_sup
  1202   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1203   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1204   INTER_fold_inter              ~> INFI_fold_inf
  1205   UNION_fold_union              ~> SUPR_fold_sup
  1206 
  1207 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1208 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1209 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1210 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1211 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1212 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1213 
  1214 * Reorganized theory Multiset: swapped notation of pointwise and
  1215 multiset order:
  1216 
  1217   - pointwise ordering is instance of class order with standard syntax
  1218     <= and <;
  1219   - multiset ordering has syntax <=# and <#; partial order properties
  1220     are provided by means of interpretation with prefix
  1221     multiset_order;
  1222   - less duplication, less historical organization of sections,
  1223     conversion from associations lists to multisets, rudimentary code
  1224     generation;
  1225   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1226     if needed.
  1227 
  1228 Renamed:
  1229 
  1230   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1231   multi_count_ext  ~>  multiset_ext
  1232   diff_union_inverse2  ~>  diff_union_cancelR
  1233 
  1234 INCOMPATIBILITY.
  1235 
  1236 * Theory Permutation: replaced local "remove" by List.remove1.
  1237 
  1238 * Code generation: ML and OCaml code is decorated with signatures.
  1239 
  1240 * Theory List: added transpose.
  1241 
  1242 * Library/Nat_Bijection.thy is a collection of bijective functions
  1243 between nat and other types, which supersedes the older libraries
  1244 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1245 
  1246   Constants:
  1247   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1248   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1249   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1250   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1251   Countable.pair_encode           ~> prod_encode
  1252   NatIso.prod2nat                 ~> prod_encode
  1253   NatIso.nat2prod                 ~> prod_decode
  1254   NatIso.sum2nat                  ~> sum_encode
  1255   NatIso.nat2sum                  ~> sum_decode
  1256   NatIso.list2nat                 ~> list_encode
  1257   NatIso.nat2list                 ~> list_decode
  1258   NatIso.set2nat                  ~> set_encode
  1259   NatIso.nat2set                  ~> set_decode
  1260 
  1261   Lemmas:
  1262   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1263   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1264   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1265   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1266   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1267   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1268   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1269   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1270   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1271   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1272   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1273   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1274   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1275 
  1276 * Sledgehammer:
  1277   - Renamed ATP commands:
  1278     atp_info     ~> sledgehammer running_atps
  1279     atp_kill     ~> sledgehammer kill_atps
  1280     atp_messages ~> sledgehammer messages
  1281     atp_minimize ~> sledgehammer minimize
  1282     print_atps   ~> sledgehammer available_atps
  1283     INCOMPATIBILITY.
  1284   - Added user's manual ("isabelle doc sledgehammer").
  1285   - Added option syntax and "sledgehammer_params" to customize
  1286     Sledgehammer's behavior.  See the manual for details.
  1287   - Modified the Isar proof reconstruction code so that it produces
  1288     direct proofs rather than proofs by contradiction.  (This feature
  1289     is still experimental.)
  1290   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1291     full-typed mode.
  1292   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1293 
  1294 * Nitpick:
  1295   - Added and implemented "binary_ints" and "bits" options.
  1296   - Added "std" option and implemented support for nonstandard models.
  1297   - Added and implemented "finitize" option to improve the precision
  1298     of infinite datatypes based on a monotonicity analysis.
  1299   - Added support for quotient types.
  1300   - Added support for "specification" and "ax_specification"
  1301     constructs.
  1302   - Added support for local definitions (for "function" and
  1303     "termination" proofs).
  1304   - Added support for term postprocessors.
  1305   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1306   - Improved efficiency of "destroy_constrs" optimization.
  1307   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1308     record getters.
  1309   - Fixed soundness bug related to higher-order constructors.
  1310   - Fixed soundness bug when "full_descrs" is enabled.
  1311   - Improved precision of set constructs.
  1312   - Added "atoms" option.
  1313   - Added cache to speed up repeated Kodkod invocations on the same
  1314     problems.
  1315   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1316     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1317     "SAT4J_Light".  INCOMPATIBILITY.
  1318   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1319     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1320   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1321 
  1322 * Method "induct" now takes instantiations of the form t, where t is not
  1323   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1324   If this is not intended, t has to be enclosed in parentheses.
  1325   By default, the equalities generated by definitional instantiations
  1326   are pre-simplified, which may cause parameters of inductive cases
  1327   to disappear, or may even delete some of the inductive cases.
  1328   Use "induct (no_simp)" instead of "induct" to restore the old
  1329   behaviour. The (no_simp) option is also understood by the "cases"
  1330   and "nominal_induct" methods, which now perform pre-simplification, too.
  1331   INCOMPATIBILITY.
  1332 
  1333 
  1334 *** HOLCF ***
  1335 
  1336 * Variable names in lemmas generated by the domain package have
  1337 changed; the naming scheme is now consistent with the HOL datatype
  1338 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1339 
  1340 * The domain package no longer defines the function "foo_copy" for
  1341 recursive domain "foo".  The reach lemma is now stated directly in
  1342 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1343 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1344 
  1345 * Most definedness lemmas generated by the domain package (previously
  1346 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1347 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1348 Proofs that used definedness lemmas as intro rules may break,
  1349 potential INCOMPATIBILITY.
  1350 
  1351 * Induction and casedist rules generated by the domain package now
  1352 declare proper case_names (one called "bottom", and one named for each
  1353 constructor).  INCOMPATIBILITY.
  1354 
  1355 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1356 rules are generated for each domain, INCOMPATIBILITY.
  1357 
  1358   foo_bar.reach       ~> foo.reach  bar.reach
  1359   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1360 
  1361 * Some lemmas generated by the domain package have been renamed for
  1362 consistency with the datatype package, INCOMPATIBILITY.
  1363 
  1364   foo.ind        ~> foo.induct
  1365   foo.finite_ind ~> foo.finite_induct
  1366   foo.coind      ~> foo.coinduct
  1367   foo.casedist   ~> foo.exhaust
  1368   foo.exhaust    ~> foo.nchotomy
  1369 
  1370 * For consistency with other definition packages, the fixrec package
  1371 now generates qualified theorem names, INCOMPATIBILITY.
  1372 
  1373   foo_simps  ~> foo.simps
  1374   foo_unfold ~> foo.unfold
  1375   foo_induct ~> foo.induct
  1376 
  1377 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1378 method and internal fixrec proofs now use the default simpset instead.
  1379 INCOMPATIBILITY.
  1380 
  1381 * The "contlub" predicate has been removed.  Proof scripts should use
  1382 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1383 
  1384 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1385 
  1386 * The constants cpair, cfst, and csnd have been removed in favor of
  1387 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1388 
  1389 
  1390 *** ML ***
  1391 
  1392 * Antiquotations for basic formal entities:
  1393 
  1394     @{class NAME}         -- type class
  1395     @{class_syntax NAME}  -- syntax representation of the above
  1396 
  1397     @{type_name NAME}     -- logical type
  1398     @{type_abbrev NAME}   -- type abbreviation
  1399     @{nonterminal NAME}   -- type of concrete syntactic category
  1400     @{type_syntax NAME}   -- syntax representation of any of the above
  1401 
  1402     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1403     @{const_abbrev NAME}  -- abbreviated constant
  1404     @{const_syntax NAME}  -- syntax representation of any of the above
  1405 
  1406 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1407 syntax constant (cf. 'syntax' command).
  1408 
  1409 * Antiquotation @{make_string} inlines a function to print arbitrary
  1410 values similar to the ML toplevel.  The result is compiler dependent
  1411 and may fall back on "?" in certain situations.
  1412 
  1413 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1414 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1415 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1416 not work with the asynchronous Isar document model.
  1417 
  1418 * Configuration options now admit dynamic default values, depending on
  1419 the context or even global references.
  1420 
  1421 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1422 uses an efficient external library if available (for Poly/ML).
  1423 
  1424 * Renamed some important ML structures, while keeping the old names
  1425 for some time as aliases within the structure Legacy:
  1426 
  1427   OuterKeyword  ~>  Keyword
  1428   OuterLex      ~>  Token
  1429   OuterParse    ~>  Parse
  1430   OuterSyntax   ~>  Outer_Syntax
  1431   PrintMode     ~>  Print_Mode
  1432   SpecParse     ~>  Parse_Spec
  1433   ThyInfo       ~>  Thy_Info
  1434   ThyLoad       ~>  Thy_Load
  1435   ThyOutput     ~>  Thy_Output
  1436   TypeInfer     ~>  Type_Infer
  1437 
  1438 Note that "open Legacy" simplifies porting of sources, but forgetting
  1439 to remove it again will complicate porting again in the future.
  1440 
  1441 * Most operations that refer to a global context are named
  1442 accordingly, e.g. Simplifier.global_context or
  1443 ProofContext.init_global.  There are some situations where a global
  1444 context actually works, but under normal circumstances one needs to
  1445 pass the proper local context through the code!
  1446 
  1447 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1448 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1449 Pretty.pp argument to merge, which is absent in the standard
  1450 Theory_Data version.
  1451 
  1452 * Sorts.certify_sort and derived "cert" operations for types and terms
  1453 no longer minimize sorts.  Thus certification at the boundary of the
  1454 inference kernel becomes invariant under addition of class relations,
  1455 which is an important monotonicity principle.  Sorts are now minimized
  1456 in the syntax layer only, at the boundary between the end-user and the
  1457 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1458 explicitly in rare situations.
  1459 
  1460 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1461 emphasize that this is in no way a standard operation.
  1462 INCOMPATIBILITY.
  1463 
  1464 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1465 usual for resolution.  Rare INCOMPATIBILITY.
  1466 
  1467 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1468 to emphasize that these only work in a global situation (which is
  1469 quite rare).
  1470 
  1471 * Curried take and drop in library.ML; negative length is interpreted
  1472 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1473 
  1474 * Proof terms: type substitutions on proof constants now use canonical
  1475 order of type variables.  INCOMPATIBILITY for tools working with proof
  1476 terms.
  1477 
  1478 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1479 may no longer carry premises.  User-level specifications are
  1480 transformed accordingly by Thm.add_axiom/add_def.
  1481 
  1482 
  1483 *** System ***
  1484 
  1485 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1486 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1487 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1488 
  1489 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1490 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1491 respectively.
  1492 
  1493 * Old lib/scripts/polyml-platform is superseded by the
  1494 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1495 variant, even on a 64 bit machine.  The following example setting
  1496 prefers 64 bit if available:
  1497 
  1498   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1499 
  1500 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1501 Isabelle/Scala layer for advanced prover interaction and integration.
  1502 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1503 component.
  1504 
  1505 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1506 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1507 similar to the default assignment of the document preparation system
  1508 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1509 provides some operations for direct access to the font without asking
  1510 the user for manual installation.
  1511 
  1512 
  1513 
  1514 New in Isabelle2009-1 (December 2009)
  1515 -------------------------------------
  1516 
  1517 *** General ***
  1518 
  1519 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1520 one backslash should be used, even in ML sources.
  1521 
  1522 
  1523 *** Pure ***
  1524 
  1525 * Locale interpretation propagates mixins along the locale hierarchy.
  1526 The currently only available mixins are the equations used to map
  1527 local definitions to terms of the target domain of an interpretation.
  1528 
  1529 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1530 loc" to print all interpretations of locale "loc" in the theory.
  1531 Interpretations in proofs are not shown.
  1532 
  1533 * Thoroughly revised locales tutorial.  New section on conditional
  1534 interpretation.
  1535 
  1536 * On instantiation of classes, remaining undefined class parameters
  1537 are formally declared.  INCOMPATIBILITY.
  1538 
  1539 
  1540 *** Document preparation ***
  1541 
  1542 * New generalized style concept for printing terms: @{foo (style) ...}
  1543 instead of @{foo_style style ...}  (old form is still retained for
  1544 backward compatibility).  Styles can be also applied for
  1545 antiquotations prop, term_type and typeof.
  1546 
  1547 
  1548 *** HOL ***
  1549 
  1550 * New proof method "smt" for a combination of first-order logic with
  1551 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1552 fixed-size bitvectors; there is also basic support for higher-order
  1553 features (esp. lambda abstractions).  It is an incomplete decision
  1554 procedure based on external SMT solvers using the oracle mechanism;
  1555 for the SMT solver Z3, this method is proof-producing.  Certificates
  1556 are provided to avoid calling the external solvers solely for
  1557 re-checking proofs.  Due to a remote SMT service there is no need for
  1558 installing SMT solvers locally.  See src/HOL/SMT.
  1559 
  1560 * New commands to load and prove verification conditions generated by
  1561 the Boogie program verifier or derived systems (e.g. the Verifying C
  1562 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1563 
  1564 * New counterexample generator tool 'nitpick' based on the Kodkod
  1565 relational model finder.  See src/HOL/Tools/Nitpick and
  1566 src/HOL/Nitpick_Examples.
  1567 
  1568 * New commands 'code_pred' and 'values' to invoke the predicate
  1569 compiler and to enumerate values of inductive predicates.
  1570 
  1571 * A tabled implementation of the reflexive transitive closure.
  1572 
  1573 * New implementation of quickcheck uses generic code generator;
  1574 default generators are provided for all suitable HOL types, records
  1575 and datatypes.  Old quickcheck can be re-activated importing theory
  1576 Library/SML_Quickcheck.
  1577 
  1578 * New testing tool Mirabelle for automated proof tools.  Applies
  1579 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1580 every proof step in a theory.  To be used in batch mode via the
  1581 "mirabelle" utility.
  1582 
  1583 * New proof method "sos" (sum of squares) for nonlinear real
  1584 arithmetic (originally due to John Harison). It requires theory
  1585 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1586 works well in practice on quantifier-free real arithmetic with +, -,
  1587 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1588 inequalities between polynomials.  It makes use of external
  1589 semidefinite programming solvers.  Method "sos" generates a
  1590 certificate that can be pasted into the proof thus avoiding the need
  1591 to call an external tool every time the proof is checked.  See
  1592 src/HOL/Library/Sum_Of_Squares.
  1593 
  1594 * New method "linarith" invokes existing linear arithmetic decision
  1595 procedure only.
  1596 
  1597 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1598 
  1599 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1600 Causes full type information to be output to the ATPs.  This slows
  1601 ATPs down considerably but eliminates a source of unsound "proofs"
  1602 that fail later.
  1603 
  1604 * New method "metisFT": A version of metis that uses full type
  1605 information in order to avoid failures of proof reconstruction.
  1606 
  1607 * New evaluator "approximate" approximates an real valued term using
  1608 the same method as the approximation method.
  1609 
  1610 * Method "approximate" now supports arithmetic expressions as
  1611 boundaries of intervals and implements interval splitting and Taylor
  1612 series expansion.
  1613 
  1614 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1615 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1616 
  1617 * New theory SupInf of the supremum and infimum operators for sets of
  1618 reals.
  1619 
  1620 * New theory Probability, which contains a development of measure
  1621 theory, eventually leading to Lebesgue integration and probability.
  1622 
  1623 * Extended Multivariate Analysis to include derivation and Brouwer's
  1624 fixpoint theorem.
  1625 
  1626 * Reorganization of number theory, INCOMPATIBILITY:
  1627   - new number theory development for nat and int, in theories Divides
  1628     and GCD as well as in new session Number_Theory
  1629   - some constants and facts now suffixed with _nat and _int
  1630     accordingly
  1631   - former session NumberTheory now named Old_Number_Theory, including
  1632     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1633   - moved theory Pocklington from src/HOL/Library to
  1634     src/HOL/Old_Number_Theory
  1635 
  1636 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1637 lcm of finite and infinite sets. It is shown that they form a complete
  1638 lattice.
  1639 
  1640 * Class semiring_div requires superclass no_zero_divisors and proof of
  1641 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1642 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1643 generalized to class semiring_div, subsuming former theorems
  1644 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1645 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1646 INCOMPATIBILITY.
  1647 
  1648 * Refinements to lattice classes and sets:
  1649   - less default intro/elim rules in locale variant, more default
  1650     intro/elim rules in class variant: more uniformity
  1651   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1652     le_inf_iff
  1653   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1654     sup_aci)
  1655   - renamed ACI to inf_sup_aci
  1656   - new class "boolean_algebra"
  1657   - class "complete_lattice" moved to separate theory
  1658     "Complete_Lattice"; corresponding constants (and abbreviations)
  1659     renamed and with authentic syntax:
  1660     Set.Inf ~>    Complete_Lattice.Inf
  1661     Set.Sup ~>    Complete_Lattice.Sup
  1662     Set.INFI ~>   Complete_Lattice.INFI
  1663     Set.SUPR ~>   Complete_Lattice.SUPR
  1664     Set.Inter ~>  Complete_Lattice.Inter
  1665     Set.Union ~>  Complete_Lattice.Union
  1666     Set.INTER ~>  Complete_Lattice.INTER
  1667     Set.UNION ~>  Complete_Lattice.UNION
  1668   - authentic syntax for
  1669     Set.Pow
  1670     Set.image
  1671   - mere abbreviations:
  1672     Set.empty               (for bot)
  1673     Set.UNIV                (for top)
  1674     Set.inter               (for inf, formerly Set.Int)
  1675     Set.union               (for sup, formerly Set.Un)
  1676     Complete_Lattice.Inter  (for Inf)
  1677     Complete_Lattice.Union  (for Sup)
  1678     Complete_Lattice.INTER  (for INFI)
  1679     Complete_Lattice.UNION  (for SUPR)
  1680   - object-logic definitions as far as appropriate
  1681 
  1682 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1683 Un_subset_iff are explicitly deleted as default simp rules; then also
  1684 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1685 deleted to achieve the desired effect.
  1686 
  1687 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1688 rules by default any longer; the same applies to min_max.inf_absorb1
  1689 etc.  INCOMPATIBILITY.
  1690 
  1691 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1692 pred_set_conv by default.  INCOMPATIBILITY.
  1693 
  1694 * Power operations on relations and functions are now one dedicated
  1695 constant "compow" with infix syntax "^^".  Power operation on
  1696 multiplicative monoids retains syntax "^" and is now defined generic
  1697 in class power.  INCOMPATIBILITY.
  1698 
  1699 * Relation composition "R O S" now has a more standard argument order:
  1700 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1701 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1702 break, since the O_assoc rule was not rewritten like this.  Fix using
  1703 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1704 
  1705 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1706 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1707 INCOMPATIBILITY.
  1708 
  1709 * Most rules produced by inductive and datatype package have mandatory
  1710 prefixes.  INCOMPATIBILITY.
  1711 
  1712 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1713 the attribute of the same name.  Each of the theorems in the list
  1714 DERIV_intros assumes composition with an additional function and
  1715 matches a variable to the derivative, which has to be solved by the
  1716 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1717 of most elementary terms.  Former Maclauren.DERIV_tac and
  1718 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1719 INCOMPATIBILITY.
  1720 
  1721 * Code generator attributes follow the usual underscore convention:
  1722     code_unfold     replaces    code unfold
  1723     code_post       replaces    code post
  1724     etc.
  1725   INCOMPATIBILITY.
  1726 
  1727 * Renamed methods:
  1728     sizechange -> size_change
  1729     induct_scheme -> induction_schema
  1730   INCOMPATIBILITY.
  1731 
  1732 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1733 INCOMPATIBILITY, use "undefined" directly.
  1734 
  1735 * Renamed theorems:
  1736     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1737     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1738     Suc_plus1 -> Suc_eq_plus1
  1739     *anti_sym -> *antisym*
  1740     vector_less_eq_def -> vector_le_def
  1741   INCOMPATIBILITY.
  1742 
  1743 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1744 INCOMPATIBILITY.
  1745 
  1746 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1747 INCOMPATIBILITY.
  1748 
  1749 
  1750 *** HOLCF ***
  1751 
  1752 * Theory Representable defines a class "rep" of domains that are
  1753 representable (via an ep-pair) in the universal domain type "udom".
  1754 Instances are provided for all type constructors defined in HOLCF.
  1755 
  1756 * The 'new_domain' command is a purely definitional version of the
  1757 domain package, for representable domains.  Syntax is identical to the
  1758 old domain package.  The 'new_domain' package also supports indirect
  1759 recursion using previously-defined type constructors.  See
  1760 src/HOLCF/ex/New_Domain.thy for examples.
  1761 
  1762 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1763 on the left-hand side of an equation, and then performs
  1764 simplification.  Rewriting is done using rules declared with the
  1765 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1766 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1767 
  1768 * The pattern-match compiler in 'fixrec' can now handle constructors
  1769 with HOL function types.  Pattern-match combinators for the Pair
  1770 constructor are pre-configured.
  1771 
  1772 * The 'fixrec' package now produces better fixed-point induction rules
  1773 for mutually-recursive definitions:  Induction rules have conclusions
  1774 of the form "P foo bar" instead of "P <foo, bar>".
  1775 
  1776 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1777 been renamed to "below".  The name "below" now replaces "less" in many
  1778 theorem names.  (Legacy theorem names using "less" are still supported
  1779 as well.)
  1780 
  1781 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1782 patterns can be used to generate strictness rules, or to make
  1783 functions more strict (much like the bang-patterns supported by the
  1784 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1785 examples.
  1786 
  1787 
  1788 *** ML ***
  1789 
  1790 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1791 errors and run-time exceptions, including detailed source positions.
  1792 
  1793 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1794 identified entries, with some additional information such as source
  1795 position, logical grouping etc.
  1796 
  1797 * Theory and context data is now introduced by the simplified and
  1798 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1799 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1800 copy operation) is still available for some time.
  1801 
  1802 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1803 provides a high-level programming interface to synchronized state
  1804 variables with atomic update.  This works via pure function
  1805 application within a critical section -- its runtime should be as
  1806 short as possible; beware of deadlocks if critical code is nested,
  1807 either directly or indirectly via other synchronized variables!
  1808 
  1809 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1810 wraps raw ML references, explicitly indicating their non-thread-safe
  1811 behaviour.  The Isar toplevel keeps this structure open, to
  1812 accommodate Proof General as well as quick and dirty interactive
  1813 experiments with references.
  1814 
  1815 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1816 parallel tactical reasoning.
  1817 
  1818 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1819 are similar to SUBPROOF, but are slightly more flexible: only the
  1820 specified parts of the subgoal are imported into the context, and the
  1821 body tactic may introduce new subgoals and schematic variables.
  1822 
  1823 * Old tactical METAHYPS, which does not observe the proof context, has
  1824 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1825 or Subgoal.FOCUS etc.
  1826 
  1827 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1828 functors have their own ML name space there is no point to mark them
  1829 separately.)  Minor INCOMPATIBILITY.
  1830 
  1831 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1832 
  1833 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1834 INCOMPATIBILITY.
  1835 
  1836 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1837 mode, which avoids critical setmp.
  1838 
  1839 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1840 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1841 Attrib/Method.setup introduced in Isabelle2009.
  1842 
  1843 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1844 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1845 last resort.  INCOMPATIBILITY.
  1846 
  1847 * Display.pretty_thm now requires a proper context (cf. former
  1848 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1849 or even Display.pretty_thm_without_context as last resort.
  1850 INCOMPATIBILITY.
  1851 
  1852 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1853 Syntax.pretty_typ/term directly, preferably with proper context
  1854 instead of global theory.
  1855 
  1856 
  1857 *** System ***
  1858 
  1859 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1860 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1861 usedir option -q.
  1862 
  1863 * Support for additional "Isabelle components" via etc/components, see
  1864 also the system manual.
  1865 
  1866 * The isabelle makeall tool now operates on all components with
  1867 IsaMakefile, not just hardwired "logics".
  1868 
  1869 * Removed "compress" option from isabelle-process and isabelle usedir;
  1870 this is always enabled.
  1871 
  1872 * Discontinued support for Poly/ML 4.x versions.
  1873 
  1874 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1875 on a given logic image.  This requires the lighttpd webserver and is
  1876 currently supported on Linux only.
  1877 
  1878 
  1879 
  1880 New in Isabelle2009 (April 2009)
  1881 --------------------------------
  1882 
  1883 *** General ***
  1884 
  1885 * Simplified main Isabelle executables, with less surprises on
  1886 case-insensitive file-systems (such as Mac OS).
  1887 
  1888   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1889     "isatool."
  1890 
  1891   - The former "isabelle" alias for "isabelle-process" has been
  1892     removed (should rarely occur to regular users).
  1893 
  1894   - The former "isabelle-interface" and its alias "Isabelle" have been
  1895     removed (interfaces are now regular Isabelle tools).
  1896 
  1897 Within scripts and make files, the Isabelle environment variables
  1898 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1899 respectively.  (The latter are still available as legacy feature.)
  1900 
  1901 The old isabelle-interface wrapper could react in confusing ways if
  1902 the interface was uninstalled or changed otherwise.  Individual
  1903 interface tool configuration is now more explicit, see also the
  1904 Isabelle system manual.  In particular, Proof General is now available
  1905 via "isabelle emacs".
  1906 
  1907 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1908 purge installed copies of Isabelle executables and re-run "isabelle
  1909 install -p ...", or use symlinks.
  1910 
  1911 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1912 old ~/isabelle, which was slightly non-standard and apt to cause
  1913 surprises on case-insensitive file-systems (such as Mac OS).
  1914 
  1915 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1916 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1917 care is required when using older releases of Isabelle.  Note that
  1918 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1919 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1920 
  1921 * Proofs of fully specified statements are run in parallel on
  1922 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1923 a regular 4-core machine, if the initial heap space is made reasonably
  1924 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1925 
  1926 * The main reference manuals ("isar-ref", "implementation", and
  1927 "system") have been updated and extended.  Formally checked references
  1928 as hyperlinks are now available uniformly.
  1929 
  1930 
  1931 *** Pure ***
  1932 
  1933 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1934 respects.  The most important changes are listed below.  See the
  1935 Tutorial on Locales ("locales" manual) for details.
  1936 
  1937 - In locale expressions, instantiation replaces renaming.  Parameters
  1938 must be declared in a for clause.  To aid compatibility with previous
  1939 parameter inheritance, in locale declarations, parameters that are not
  1940 'touched' (instantiation position "_" or omitted) are implicitly added
  1941 with their syntax at the beginning of the for clause.
  1942 
  1943 - Syntax from abbreviations and definitions in locales is available in
  1944 locale expressions and context elements.  The latter is particularly
  1945 useful in locale declarations.
  1946 
  1947 - More flexible mechanisms to qualify names generated by locale
  1948 expressions.  Qualifiers (prefixes) may be specified in locale
  1949 expressions, and can be marked as mandatory (syntax: "name!:") or
  1950 optional (syntax "name?:").  The default depends for plain "name:"
  1951 depends on the situation where a locale expression is used: in
  1952 commands 'locale' and 'sublocale' prefixes are optional, in
  1953 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1954 implicit qualifiers derived from the parameter names of a locale are
  1955 no longer generated.
  1956 
  1957 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1958 instantiation clause in "interpretation" and "interpret" (square
  1959 brackets) is no longer available.  Use locale expressions.
  1960 
  1961 - When converting proof scripts, mandatory qualifiers in
  1962 'interpretation' and 'interpret' should be retained by default, even
  1963 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1964 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1965 in locale expressions range over a single locale instance only.
  1966 
  1967 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1968 In existing theorem specifications replace the includes element by the
  1969 respective context elements of the included locale, omitting those
  1970 that are already present in the theorem specification.  Multiple
  1971 assume elements of a locale should be replaced by a single one
  1972 involving the locale predicate.  In the proof body, declarations (most
  1973 notably theorems) may be regained by interpreting the respective
  1974 locales in the proof context as required (command "interpret").
  1975 
  1976 If using "includes" in replacement of a target solely because the
  1977 parameter types in the theorem are not as general as in the target,
  1978 consider declaring a new locale with additional type constraints on
  1979 the parameters (context element "constrains").
  1980 
  1981 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1982 
  1983 - Locale interpretation commands no longer attempt to simplify goal.
  1984 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1985 methods intro_locales and unfold_locales to clarify.
  1986 
  1987 - Locale interpretation commands no longer accept interpretation
  1988 attributes.  INCOMPATIBILITY.
  1989 
  1990 * Class declaration: so-called "base sort" must not be given in import
  1991 list any longer, but is inferred from the specification.  Particularly
  1992 in HOL, write
  1993 
  1994     class foo = ...
  1995 
  1996 instead of
  1997 
  1998     class foo = type + ...
  1999 
  2000 * Class target: global versions of theorems stemming do not carry a
  2001 parameter prefix any longer.  INCOMPATIBILITY.
  2002 
  2003 * Class 'instance' command no longer accepts attached definitions.
  2004 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2005 
  2006 * Recovered hiding of consts, which was accidentally broken in
  2007 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2008 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2009 
  2010 * Slightly more coherent Pure syntax, with updated documentation in
  2011 isar-ref manual.  Removed locales meta_term_syntax and
  2012 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2013 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2014 directly in regular applications.
  2015 
  2016 * There is a new syntactic category "float_const" for signed decimal
  2017 fractions (e.g. 123.45 or -123.45).
  2018 
  2019 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2020 interface with 'setup' command instead.
  2021 
  2022 * Command 'local_setup' is similar to 'setup', but operates on a local
  2023 theory context.
  2024 
  2025 * The 'axiomatization' command now only works within a global theory
  2026 context.  INCOMPATIBILITY.
  2027 
  2028 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2029 hypotheses.  Sorts required in the course of reasoning need to be
  2030 covered by the constraints in the initial statement, completed by the
  2031 type instance information of the background theory.  Non-trivial sort
  2032 hypotheses, which rarely occur in practice, may be specified via
  2033 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2034 
  2035   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2036 
  2037 The result contains an implicit sort hypotheses as before --
  2038 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2039 normalization.
  2040 
  2041 * Generalized Isar history, with support for linear undo, direct state
  2042 addressing etc.
  2043 
  2044 * Changed defaults for unify configuration options:
  2045 
  2046   unify_trace_bound = 50 (formerly 25)
  2047   unify_search_bound = 60 (formerly 30)
  2048 
  2049 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2050 
  2051   a) On theory merge, the last set of code equations for a particular
  2052      constant is taken (in accordance with the policy applied by other
  2053      parts of the code generator framework).
  2054 
  2055   b) Code equations stemming from explicit declarations (e.g. code
  2056      attribute) gain priority over default code equations stemming
  2057      from definition, primrec, fun etc.
  2058 
  2059 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2060 
  2061 * Unified theorem tables for both code generators.  Thus [code
  2062 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2063 
  2064 * Command 'find_consts' searches for constants based on type and name
  2065 patterns, e.g.
  2066 
  2067     find_consts "_ => bool"
  2068 
  2069 By default, matching is against subtypes, but it may be restricted to
  2070 the whole type.  Searching by name is possible.  Multiple queries are
  2071 conjunctive and queries may be negated by prefixing them with a
  2072 hyphen:
  2073 
  2074     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2075 
  2076 * New 'find_theorems' criterion "solves" matches theorems that
  2077 directly solve the current goal (modulo higher-order unification).
  2078 
  2079 * Auto solve feature for main theorem statements: whenever a new goal
  2080 is stated, "find_theorems solves" is called; any theorems that could
  2081 solve the lemma directly are listed as part of the goal state.
  2082 Cf. associated options in Proof General Isabelle settings menu,
  2083 enabled by default, with reasonable timeout for pathological cases of
  2084 higher-order unification.
  2085 
  2086 
  2087 *** Document preparation ***
  2088 
  2089 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2090 demanding keyword 'by' and supporting the full method expression
  2091 syntax just like the Isar command 'by'.
  2092 
  2093 
  2094 *** HOL ***
  2095 
  2096 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2097 points Main and Complex_Main remain as before.
  2098 
  2099 * Logic image HOL-Plain provides a minimal HOL with the most important
  2100 tools available (inductive, datatype, primrec, ...).  This facilitates
  2101 experimentation and tool development.  Note that user applications
  2102 (and library theories) should never refer to anything below theory
  2103 Main, as before.
  2104 
  2105 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2106 experimentation due to shorter build times.
  2107 
  2108 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2109 were previously part of former HOL-Complex.  Entry point Hyperreal
  2110 remains valid, but theories formerly using Complex_Main should now use
  2111 new entry point Hypercomplex.
  2112 
  2113 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2114 Posix processes.  Avoids potentially expensive forking of the ML
  2115 process.  New thread-based implementation also works on non-Unix
  2116 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2117 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2118 commands are covered in the isar-ref manual.
  2119 
  2120 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2121 sledgehammer without local ATP installation (Vampire etc.). Other
  2122 provers may be included via suitable ML wrappers, see also
  2123 src/HOL/ATP_Linkup.thy.
  2124 
  2125 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2126 menu.
  2127 
  2128 * The metis method no longer fails because the theorem is too trivial
  2129 (contains the empty clause).
  2130 
  2131 * The metis method now fails in the usual manner, rather than raising
  2132 an exception, if it determines that it cannot prove the theorem.
  2133 
  2134 * Method "coherent" implements a prover for coherent logic (see also
  2135 src/Tools/coherent.ML).
  2136 
  2137 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2138 "undefined" is the right choice to replace "arbitrary", though
  2139 logically there is no difference.  INCOMPATIBILITY.
  2140 
  2141 * Command "value" now integrates different evaluation mechanisms.  The
  2142 result of the first successful evaluation mechanism is printed.  In
  2143 square brackets a particular named evaluation mechanisms may be
  2144 specified (currently, [SML], [code] or [nbe]).  See further
  2145 src/HOL/ex/Eval_Examples.thy.
  2146 
  2147 * Normalization by evaluation now allows non-leftlinear equations.
  2148 Declare with attribute [code nbe].
  2149 
  2150 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2151 as the structured Isar versions "cases" and "induct", cf. the
  2152 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2153 are now presented as a list of individual projections
  2154 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2155 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2156 rare situations a different rule is selected --- notably nested tuple
  2157 elimination instead of former prod.exhaust: use explicit (case_tac t
  2158 rule: prod.exhaust) here.
  2159 
  2160 * Attributes "cases", "induct", "coinduct" support "del" option.
  2161 
  2162 * Removed fact "case_split_thm", which duplicates "case_split".
  2163 
  2164 * The option datatype has been moved to a new theory Option.  Renamed
  2165 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2166 
  2167 * New predicate "strict_mono" classifies strict functions on partial
  2168 orders.  With strict functions on linear orders, reasoning about
  2169 (in)equalities is facilitated by theorems "strict_mono_eq",
  2170 "strict_mono_less_eq" and "strict_mono_less".
  2171 
  2172 * Some set operations are now proper qualified constants with
  2173 authentic syntax.  INCOMPATIBILITY:
  2174 
  2175     op Int ~>   Set.Int
  2176     op Un ~>    Set.Un
  2177     INTER ~>    Set.INTER
  2178     UNION ~>    Set.UNION
  2179     Inter ~>    Set.Inter
  2180     Union ~>    Set.Union
  2181     {} ~>       Set.empty
  2182     UNIV ~>     Set.UNIV
  2183 
  2184 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2185 theory Set.
  2186 
  2187 * Auxiliary class "itself" has disappeared -- classes without any
  2188 parameter are treated as expected by the 'class' command.
  2189 
  2190 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2191 
  2192 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2193 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2194 
  2195 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2196 method "approximation".  It proves formulas on real values by using
  2197 interval arithmetic.  In the formulas are also the transcendental
  2198 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2199 allowed. For examples see
  2200 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2201 
  2202 * Theory "Reflection" now resides in HOL/Library.
  2203 
  2204 * Entry point to Word library now simply named "Word".
  2205 INCOMPATIBILITY.
  2206 
  2207 * Made source layout more coherent with logical distribution
  2208 structure:
  2209 
  2210     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2211     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2212     src/HOL/Library/GCD.thy ~> src/HOL/
  2213     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2214     src/HOL/Library/Parity.thy ~> src/HOL/
  2215     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2216     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2217     src/HOL/Real/Lubs.thy ~> src/HOL/
  2218     src/HOL/Real/PReal.thy ~> src/HOL/
  2219     src/HOL/Real/Rational.thy ~> src/HOL/
  2220     src/HOL/Real/RComplete.thy ~> src/HOL/
  2221     src/HOL/Real/RealDef.thy ~> src/HOL/
  2222     src/HOL/Real/RealPow.thy ~> src/HOL/
  2223     src/HOL/Real/Real.thy ~> src/HOL/
  2224     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2225     src/HOL/Complex/Complex.thy ~> src/HOL/
  2226     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2227     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2228     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2229     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2230     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2231     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2232     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2233     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2234     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2235     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2236     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2237     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2238     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2239     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2240     src/HOL/Real/Float ~> src/HOL/Library/
  2241     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2242     src/HOL/Real/RealVector.thy ~> src/HOL/
  2243 
  2244     src/HOL/arith_data.ML ~> src/HOL/Tools
  2245     src/HOL/hologic.ML ~> src/HOL/Tools
  2246     src/HOL/simpdata.ML ~> src/HOL/Tools
  2247     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2248     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2249     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2250     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2251     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2252     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2253     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2254 
  2255     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2256     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2257     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2258     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2259     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2260     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2261 
  2262 * If methods "eval" and "evaluation" encounter a structured proof
  2263 state with !!/==>, only the conclusion is evaluated to True (if
  2264 possible), avoiding strange error messages.
  2265 
  2266 * Method "sizechange" automates termination proofs using (a
  2267 modification of) the size-change principle.  Requires SAT solver.  See
  2268 src/HOL/ex/Termination.thy for examples.
  2269 
  2270 * Simplifier: simproc for let expressions now unfolds if bound
  2271 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2272 
  2273 * Method "arith": Linear arithmetic now ignores all inequalities when
  2274 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2275 
  2276 * New attribute "arith" for facts that should always be used
  2277 automatically by arithmetic. It is intended to be used locally in
  2278 proofs, e.g.
  2279 
  2280   assumes [arith]: "x > 0"
  2281 
  2282 Global usage is discouraged because of possible performance impact.
  2283 
  2284 * New classes "top" and "bot" with corresponding operations "top" and
  2285 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2286 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2287 
  2288 * Changed definition lemma "less_fun_def" in order to provide an
  2289 instance for preorders on functions; use lemma "less_le" instead.
  2290 INCOMPATIBILITY.
  2291 
  2292 * Theory Orderings: class "wellorder" moved here, with explicit
  2293 induction rule "less_induct" as assumption.  For instantiation of
  2294 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2295 INCOMPATIBILITY.
  2296 
  2297 * Theory Orderings: added class "preorder" as superclass of "order".
  2298 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2299 etc. slightly changed.  Some theorems named order_class.* now named
  2300 preorder_class.*.
  2301 
  2302 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2303 "diag" to "Id_on".
  2304 
  2305 * Theory Finite_Set: added a new fold combinator of type
  2306 
  2307   ('a => 'b => 'b) => 'b => 'a set => 'b
  2308 
  2309 Occasionally this is more convenient than the old fold combinator
  2310 which is now defined in terms of the new one and renamed to
  2311 fold_image.
  2312 
  2313 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2314 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2315 extended with further lemmas!).  At the moment both still exist but
  2316 the former will disappear at some point.
  2317 
  2318 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2319 class recpower.  Type-specific simp rules for various recpower types
  2320 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2321 
  2322 rat_power_0    -> power_0
  2323 rat_power_Suc  -> power_Suc
  2324 realpow_0      -> power_0
  2325 realpow_Suc    -> power_Suc
  2326 complexpow_0   -> power_0
  2327 complexpow_Suc -> power_Suc
  2328 power_poly_0   -> power_0
  2329 power_poly_Suc -> power_Suc
  2330 
  2331 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2332 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2333 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2334 of lemmas from Divides has been generalized from nat to class
  2335 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2336 renames resulting from duplicate elimination:
  2337 
  2338     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2339     zero_dvd_iff ~>         dvd_0_left_iff
  2340     dvd_0 ~>                dvd_0_right
  2341     DIVISION_BY_ZERO_DIV ~> div_by_0
  2342     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2343     mult_div ~>             div_mult_self2_is_id
  2344     mult_mod ~>             mod_mult_self2_is_0
  2345 
  2346 * Theory IntDiv: removed many lemmas that are instances of class-based
  2347 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2348 rename old lemmas as follows:
  2349 
  2350 dvd_diff               -> nat_dvd_diff
  2351 dvd_zminus_iff         -> dvd_minus_iff
  2352 mod_add1_eq            -> mod_add_eq
  2353 mod_mult1_eq           -> mod_mult_right_eq
  2354 mod_mult1_eq'          -> mod_mult_left_eq
  2355 mod_mult_distrib_mod   -> mod_mult_eq
  2356 nat_mod_add_left_eq    -> mod_add_left_eq
  2357 nat_mod_add_right_eq   -> mod_add_right_eq
  2358 nat_mod_div_trivial    -> mod_div_trivial
  2359 nat_mod_mod_trivial    -> mod_mod_trivial
  2360 zdiv_zadd_self1        -> div_add_self1
  2361 zdiv_zadd_self2        -> div_add_self2
  2362 zdiv_zmult_self1       -> div_mult_self2_is_id
  2363 zdiv_zmult_self2       -> div_mult_self1_is_id
  2364 zdvd_triv_left         -> dvd_triv_left
  2365 zdvd_triv_right        -> dvd_triv_right
  2366 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2367 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2368 zmod_zadd_left_eq      -> mod_add_left_eq
  2369 zmod_zadd_right_eq     -> mod_add_right_eq
  2370 zmod_zadd_self1        -> mod_add_self1
  2371 zmod_zadd_self2        -> mod_add_self2
  2372 zmod_zadd1_eq          -> mod_add_eq
  2373 zmod_zdiff1_eq         -> mod_diff_eq
  2374 zmod_zdvd_zmod         -> mod_mod_cancel
  2375 zmod_zmod_cancel       -> mod_mod_cancel
  2376 zmod_zmult_self1       -> mod_mult_self2_is_0
  2377 zmod_zmult_self2       -> mod_mult_self1_is_0
  2378 zmod_1                 -> mod_by_1
  2379 zdiv_1                 -> div_by_1
  2380 zdvd_abs1              -> abs_dvd_iff
  2381 zdvd_abs2              -> dvd_abs_iff
  2382 zdvd_refl              -> dvd_refl
  2383 zdvd_trans             -> dvd_trans
  2384 zdvd_zadd              -> dvd_add
  2385 zdvd_zdiff             -> dvd_diff
  2386 zdvd_zminus_iff        -> dvd_minus_iff
  2387 zdvd_zminus2_iff       -> minus_dvd_iff
  2388 zdvd_zmultD            -> dvd_mult_right
  2389 zdvd_zmultD2           -> dvd_mult_left
  2390 zdvd_zmult_mono        -> mult_dvd_mono
  2391 zdvd_0_right           -> dvd_0_right
  2392 zdvd_0_left            -> dvd_0_left_iff
  2393 zdvd_1_left            -> one_dvd
  2394 zminus_dvd_iff         -> minus_dvd_iff
  2395 
  2396 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2397 
  2398 * The real numbers offer decimal input syntax: 12.34 is translated
  2399 into 1234/10^2. This translation is not reversed upon output.
  2400 
  2401 * Theory Library/Polynomial defines an abstract type 'a poly of
  2402 univariate polynomials with coefficients of type 'a.  In addition to
  2403 the standard ring operations, it also supports div and mod.  Code
  2404 generation is also supported, using list-style constructors.
  2405 
  2406 * Theory Library/Inner_Product defines a class of real_inner for real
  2407 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2408 => real.  Class real_inner is a subclass of real_normed_vector from
  2409 theory RealVector.
  2410 
  2411 * Theory Library/Product_Vector provides instances for the product
  2412 type 'a * 'b of several classes from RealVector and Inner_Product.
  2413 Definitions of addition, subtraction, scalar multiplication, norms,
  2414 and inner products are included.
  2415 
  2416 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2417 addition to the field operations, numerals and case syntax are also
  2418 supported.
  2419 
  2420 * Theory Library/Diagonalize provides constructive version of Cantor's
  2421 first diagonalization argument.
  2422 
  2423 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2424 zlcm (for int); carried together from various gcd/lcm developements in
  2425 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2426 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2427 may recover tupled syntax as follows:
  2428 
  2429     hide (open) const gcd
  2430     abbreviation gcd where
  2431       "gcd == (%(a, b). GCD.gcd a b)"
  2432     notation (output)
  2433       GCD.gcd ("gcd '(_, _')")
  2434 
  2435 The same works for lcm, zgcd, zlcm.
  2436 
  2437 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2438 instantiations for algebraic structures.  Removed some duplicate
  2439 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2440 
  2441 * ML antiquotation @{code} takes a constant as argument and generates
  2442 corresponding code in background and inserts name of the corresponding
  2443 resulting ML value/function/datatype constructor binding in place.
  2444 All occurrences of @{code} with a single ML block are generated
  2445 simultaneously.  Provides a generic and safe interface for
  2446 instrumentalizing code generation.  See
  2447 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2448 In future you ought to refrain from ad-hoc compiling generated SML
  2449 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2450 cannot refer to constants for which user-defined serializations are
  2451 set.  Refer to the corresponding ML counterpart directly in that
  2452 cases.
  2453 
  2454 * Command 'rep_datatype': instead of theorem names the command now
  2455 takes a list of terms denoting the constructors of the type to be
  2456 represented as datatype.  The characteristic theorems have to be
  2457 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2458 have disappeared in favour of existing ones:
  2459 
  2460     unit_induct                 ~> unit.induct
  2461     prod_induct                 ~> prod.induct
  2462     sum_induct                  ~> sum.induct
  2463     Suc_Suc_eq                  ~> nat.inject
  2464     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2465 
  2466 
  2467 *** HOL-Algebra ***
  2468 
  2469 * New locales for orders and lattices where the equivalence relation
  2470 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2471 locales use a record structure with field eq for the equivalence.
  2472 
  2473 * New theory of factorial domains.
  2474 
  2475 * Units_l_inv and Units_r_inv are now simp rules by default.
  2476 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2477 and/or r_inv will now also require deletion of these lemmas.
  2478 
  2479 * Renamed the following theorems, INCOMPATIBILITY:
  2480 
  2481 UpperD ~> Upper_memD
  2482 LowerD ~> Lower_memD
  2483 least_carrier ~> least_closed
  2484 greatest_carrier ~> greatest_closed
  2485 greatest_Lower_above ~> greatest_Lower_below
  2486 one_zero ~> carrier_one_zero
  2487 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2488 
  2489 
  2490 *** HOL-Nominal ***
  2491 
  2492 * Nominal datatypes can now contain type-variables.
  2493 
  2494 * Commands 'nominal_inductive' and 'equivariance' work with local
  2495 theory targets.
  2496 
  2497 * Nominal primrec can now works with local theory targets and its
  2498 specification syntax now conforms to the general format as seen in
  2499 'inductive' etc.
  2500 
  2501 * Method "perm_simp" honours the standard simplifier attributes
  2502 (no_asm), (no_asm_use) etc.
  2503 
  2504 * The new predicate #* is defined like freshness, except that on the
  2505 left hand side can be a set or list of atoms.
  2506 
  2507 * Experimental command 'nominal_inductive2' derives strong induction
  2508 principles for inductive definitions.  In contrast to
  2509 'nominal_inductive', which can only deal with a fixed number of
  2510 binders, it can deal with arbitrary expressions standing for sets of
  2511 atoms to be avoided.  The only inductive definition we have at the
  2512 moment that needs this generalisation is the typing rule for Lets in
  2513 the algorithm W:
  2514 
  2515  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2516  -----------------------------------------------------------------
  2517          Gamma |- Let x be t1 in t2 : T2
  2518 
  2519 In this rule one wants to avoid all the binders that are introduced by
  2520 "close Gamma T1".  We are looking for other examples where this
  2521 feature might be useful.  Please let us know.
  2522 
  2523 
  2524 *** HOLCF ***
  2525 
  2526 * Reimplemented the simplification procedure for proving continuity
  2527 subgoals.  The new simproc is extensible; users can declare additional
  2528 continuity introduction rules with the attribute [cont2cont].
  2529 
  2530 * The continuity simproc now uses a different introduction rule for
  2531 solving continuity subgoals on terms with lambda abstractions.  In
  2532 some rare cases the new simproc may fail to solve subgoals that the
  2533 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2534 Potential INCOMPATIBILITY.
  2535 
  2536 * Command 'fixrec': specification syntax now conforms to the general
  2537 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2538 examples.  INCOMPATIBILITY.
  2539 
  2540 
  2541 *** ZF ***
  2542 
  2543 * Proof of Zorn's Lemma for partial orders.
  2544 
  2545 
  2546 *** ML ***
  2547 
  2548 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2549 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2550 depends on multithreading, so timouts will not work before Poly/ML
  2551 5.2.1!
  2552 
  2553 * High-level support for concurrent ML programming, see
  2554 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2555 particularly convenient to organize independent functional
  2556 computations.  The concept of "synchronized variables" provides a
  2557 higher-order interface for components with shared state, avoiding the
  2558 delicate details of mutexes and condition variables.  (Requires
  2559 Poly/ML 5.2.1 or later.)
  2560 
  2561 * ML bindings produced via Isar commands are stored within the Isar
  2562 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2563 become thread-safe and work with undo as expected (concerning
  2564 top-level bindings, not side-effects on global references).
  2565 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2566 compiler at runtime; really global bindings need to be given outside a
  2567 theory.  (Requires Poly/ML 5.2 or later.)
  2568 
  2569 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2570 context.  Top-level ML bindings are stored within the proof context in
  2571 a purely sequential fashion, disregarding the nested proof structure.
  2572 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2573 proof.  (Requires Poly/ML 5.2 or later.)
  2574 
  2575 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2576 and Method.setup, as well as Isar commands 'attribute_setup' and
  2577 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2578 existing code accordingly, or use plain 'setup' together with old
  2579 Method.add_method.
  2580 
  2581 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2582 to 'a -> thm, while results are always tagged with an authentic oracle
  2583 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2584 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2585 accordingly.  Note that extra performance may be gained by producing
  2586 the cterm carefully, avoiding slow Thm.cterm_of.
  2587 
  2588 * Simplified interface for defining document antiquotations via
  2589 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2590 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2591 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2592 examples.
  2593 
  2594 * More systematic treatment of long names, abstract name bindings, and
  2595 name space operations.  Basic operations on qualified names have been
  2596 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2597 Long_Name.append.  Old type bstring has been mostly replaced by
  2598 abstract type binding (see structure Binding), which supports precise
  2599 qualification by packages and local theory targets, as well as proper
  2600 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2601 bstring values into Binding.name, or better pass through abstract
  2602 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2603 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2604 
  2605 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2606 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2607 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2608 
  2609 * Disposed old type and term read functions (Sign.read_def_typ,
  2610 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2611 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2612 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2613 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2614 resort for legacy applications.
  2615 
  2616 * Disposed old declarations, tactics, tactic combinators that refer to
  2617 the simpset or claset of an implicit theory (such as Addsimps,
  2618 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2619 embedded ML text, or local_simpset_of with a proper context passed as
  2620 explicit runtime argument.
  2621 
  2622 * Rules and tactics that read instantiations (read_instantiate,
  2623 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2624 context, which is required for parsing and type-checking.  Moreover,
  2625 the variables are specified as plain indexnames, not string encodings
  2626 thereof.  INCOMPATIBILITY.
  2627 
  2628 * Generic Toplevel.add_hook interface allows to analyze the result of
  2629 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2630 for theorem dependency output of transactions resulting in a new
  2631 theory state.
  2632 
  2633 * ML antiquotations: block-structured compilation context indicated by
  2634 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2635 
  2636   @{binding name}                         - basic name binding
  2637   @{let ?pat = term}                      - term abbreviation (HO matching)
  2638   @{note name = fact}                     - fact abbreviation
  2639   @{thm fact}                             - singleton fact (with attributes)
  2640   @{thms fact}                            - general fact (with attributes)
  2641   @{lemma prop by method}                 - singleton goal
  2642   @{lemma prop by meth1 meth2}            - singleton goal
  2643   @{lemma prop1 ... propN by method}      - general goal
  2644   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2645   @{lemma (open) ...}                     - open derivation
  2646 
  2647 
  2648 *** System ***
  2649 
  2650 * The Isabelle "emacs" tool provides a specific interface to invoke
  2651 Proof General / Emacs, with more explicit failure if that is not
  2652 installed (the old isabelle-interface script silently falls back on
  2653 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2654 installation location of the Proof General distribution.
  2655 
  2656 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2657 the Isabelle process into a JVM/Scala application.  See
  2658 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2659 process wrapper has been discontinued.)
  2660 
  2661 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2662 
  2663 * Various status messages (with exact source position information) are
  2664 emitted, if proper markup print mode is enabled.  This allows
  2665 user-interface components to provide detailed feedback on internal
  2666 prover operations.
  2667 
  2668 
  2669 
  2670 New in Isabelle2008 (June 2008)
  2671 -------------------------------
  2672 
  2673 *** General ***
  2674 
  2675 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2676 and updated, with formally checked references as hyperlinks.
  2677 
  2678 * Theory loader: use_thy (and similar operations) no longer set the
  2679 implicit ML context, which was occasionally hard to predict and in
  2680 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2681 provides a proper context already.
  2682 
  2683 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2684 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2685 'use' within a theory file will do the job.
  2686 
  2687 * Name space merge now observes canonical order, i.e. the second space
  2688 is inserted into the first one, while existing entries in the first
  2689 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2690 swap theory imports.
  2691 
  2692 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2693 INCOMPATIBILITY in identifier syntax etc.
  2694 
  2695 * Outer syntax: string tokens no longer admit escaped white space,
  2696 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2697 white space without escapes.
  2698 
  2699 * Outer syntax: string tokens may contain arbitrary character codes
  2700 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2701 "foo_bar".
  2702 
  2703 
  2704 *** Pure ***
  2705 
  2706 * Context-dependent token translations.  Default setup reverts locally
  2707 fixed variables, and adds hilite markup for undeclared frees.
  2708 
  2709 * Unused theorems can be found using the new command 'unused_thms'.
  2710 There are three ways of invoking it:
  2711 
  2712 (1) unused_thms
  2713      Only finds unused theorems in the current theory.
  2714 
  2715 (2) unused_thms thy_1 ... thy_n -
  2716      Finds unused theorems in the current theory and all of its ancestors,
  2717      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2718 
  2719 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2720      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2721      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2722      their ancestors.
  2723 
  2724 In order to increase the readability of the list produced by
  2725 unused_thms, theorems that have been created by a particular instance
  2726 of a theory command such as 'inductive' or 'function' are considered
  2727 to belong to the same "group", meaning that if at least one theorem in
  2728 this group is used, the other theorems in the same group are no longer
  2729 reported as unused.  Moreover, if all theorems in the group are
  2730 unused, only one theorem in the group is displayed.
  2731 
  2732 Note that proof objects have to be switched on in order for
  2733 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2734 usually the case when using Proof General with the default settings).
  2735 
  2736 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2737 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2738 duplicate fact bindings, or even accidental fact duplications.  Note
  2739 that tools may maintain dynamically scoped facts systematically, using
  2740 PureThy.add_thms_dynamic.
  2741 
  2742 * Command 'hide' now allows to hide from "fact" name space as well.
  2743 
  2744 * Eliminated destructive theorem database, simpset, claset, and
  2745 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2746 update of theories within ML code.
  2747 
  2748 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2749 INCOMPATIBILITY, object-logics depending on former Pure require
  2750 additional setup PureThy.old_appl_syntax_setup; object-logics
  2751 depending on former CPure need to refer to Pure.
  2752 
  2753 * Commands 'use' and 'ML' are now purely functional, operating on
  2754 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2755 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2756 INCOMPATIBILITY.
  2757 
  2758 * Command 'setup': discontinued implicit version with ML reference.
  2759 
  2760 * Instantiation target allows for simultaneous specification of class
  2761 instance operations together with an instantiation proof.
  2762 Type-checking phase allows to refer to class operations uniformly.
  2763 See src/HOL/Complex/Complex.thy for an Isar example and
  2764 src/HOL/Library/Eval.thy for an ML example.
  2765 
  2766 * Indexing of literal facts: be more serious about including only
  2767 facts from the visible specification/proof context, but not the
  2768 background context (locale etc.).  Affects `prop` notation and method
  2769 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2770 situations.
  2771 
  2772 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2773 "(open)" option, which used to expose internal bound variables to the
  2774 proof text.
  2775 
  2776 * Isar statements: removed obsolete case "rule_context".
  2777 INCOMPATIBILITY, better use explicit fixes/assumes.
  2778 
  2779 * Locale proofs: default proof step now includes 'unfold_locales';
  2780 hence 'proof' without argument may be used to unfold locale
  2781 predicates.
  2782 
  2783 
  2784 *** Document preparation ***
  2785 
  2786 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2787 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2788 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2789 spot); renamed link color from "darkblue" to "linkcolor" (default
  2790 value unchanged, can be redefined via \definecolor); no longer sets
  2791 "a4paper" option (unnecessary or even intrusive).
  2792 
  2793 * Antiquotation @{lemma A method} proves proposition A by the given
  2794 method (either a method name or a method name plus (optional) method
  2795 arguments in parentheses) and prints A just like @{prop A}.
  2796 
  2797 
  2798 *** HOL ***
  2799 
  2800 * New primrec package.  Specification syntax conforms in style to
  2801 definition/function/....  No separate induction rule is provided.  The
  2802 "primrec" command distinguishes old-style and new-style specifications
  2803 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2804 When adjusting theories, beware: constants stemming from new-style
  2805 primrec specifications have authentic syntax.
  2806 
  2807 * Metis prover is now an order of magnitude faster, and also works
  2808 with multithreading.
  2809 
  2810 * Metis: the maximum number of clauses that can be produced from a
  2811 theorem is now given by the attribute max_clauses.  Theorems that
  2812 exceed this number are ignored, with a warning printed.
  2813 
  2814 * Sledgehammer no longer produces structured proofs by default. To
  2815 enable, declare [[sledgehammer_full = true]].  Attributes
  2816 reconstruction_modulus, reconstruction_sorts renamed
  2817 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2818 
  2819 * Method "induct_scheme" derives user-specified induction rules
  2820 from well-founded induction and completeness of patterns. This factors
  2821 out some operations that are done internally by the function package
  2822 and makes them available separately.  See
  2823 src/HOL/ex/Induction_Scheme.thy for examples.
  2824 
  2825 * More flexible generation of measure functions for termination
  2826 proofs: Measure functions can be declared by proving a rule of the
  2827 form "is_measure f" and giving it the [measure_function] attribute.
  2828 The "is_measure" predicate is logically meaningless (always true), and
  2829 just guides the heuristic.  To find suitable measure functions, the
  2830 termination prover sets up the goal "is_measure ?f" of the appropriate
  2831 type and generates all solutions by prolog-style backwards proof using
  2832 the declared rules.
  2833 
  2834 This setup also deals with rules like 
  2835 
  2836   "is_measure f ==> is_measure (list_size f)"
  2837 
  2838 which accommodates nested datatypes that recurse through lists.
  2839 Similar rules are predeclared for products and option types.
  2840 
  2841 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2842 
  2843   INCOMPATIBILITIES:
  2844 
  2845   - Definitions of overloaded constants on sets have to be replaced by
  2846     definitions on => and bool.
  2847 
  2848   - Some definitions of overloaded operators on sets can now be proved
  2849     using the definitions of the operators on => and bool.  Therefore,
  2850     the following theorems have been renamed:
  2851 
  2852       subset_def   -> subset_eq
  2853       psubset_def  -> psubset_eq
  2854       set_diff_def -> set_diff_eq
  2855       Compl_def    -> Compl_eq
  2856       Sup_set_def  -> Sup_set_eq
  2857       Inf_set_def  -> Inf_set_eq
  2858       sup_set_def  -> sup_set_eq
  2859       inf_set_def  -> inf_set_eq
  2860 
  2861   - Due to the incompleteness of the HO unification algorithm, some
  2862     rules such as subst may require manual instantiation, if some of
  2863     the unknowns in the rule is a set.
  2864 
  2865   - Higher order unification and forward proofs:
  2866     The proof pattern
  2867 
  2868       have "P (S::'a set)" <...>
  2869       then have "EX S. P S" ..
  2870 
  2871     no longer works (due to the incompleteness of the HO unification
  2872     algorithm) and must be replaced by the pattern
  2873 
  2874       have "EX S. P S"
  2875       proof
  2876         show "P S" <...>
  2877       qed
  2878 
  2879   - Calculational reasoning with subst (or similar rules):
  2880     The proof pattern
  2881 
  2882       have "P (S::'a set)" <...>
  2883       also have "S = T" <...>
  2884       finally have "P T" .
  2885 
  2886     no longer works (for similar reasons as the previous example) and
  2887     must be replaced by something like
  2888 
  2889       have "P (S::'a set)" <...>
  2890       moreover have "S = T" <...>
  2891       ultimately have "P T" by simp
  2892 
  2893   - Tactics or packages written in ML code:
  2894     Code performing pattern matching on types via
  2895 
  2896       Type ("set", [T]) => ...
  2897 
  2898     must be rewritten. Moreover, functions like strip_type or
  2899     binder_types no longer return the right value when applied to a
  2900     type of the form
  2901 
  2902       T1 => ... => Tn => U => bool
  2903 
  2904     rather than
  2905 
  2906       T1 => ... => Tn => U set
  2907 
  2908 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2909 Wellfounded_Relations to theory Wellfounded.
  2910 
  2911 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2912 
  2913 * Class finite no longer treats UNIV as class parameter.  Use class
  2914 enum from theory Library/Enum instead to achieve a similar effect.
  2915 INCOMPATIBILITY.
  2916 
  2917 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2918 and "Cons".  INCOMPATIBILITY.
  2919 
  2920 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2921 Potential INCOMPATIBILITY.
  2922 
  2923 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2924 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2925 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2926 
  2927 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2928 the same name in theory Orderings:
  2929 
  2930   less_trans
  2931   less_linear
  2932   le_imp_less_or_eq
  2933   le_less_trans
  2934   less_le_trans
  2935   less_not_sym
  2936   less_asym
  2937 
  2938 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2939 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2940 and different variable names.
  2941 
  2942 * Library/Option_ord.thy: Canonical order on option type.
  2943 
  2944 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2945 finite maps.
  2946 
  2947 * Library/Countable.thy: Type class for countable types.
  2948 
  2949 * Theory Int: The representation of numerals has changed.  The infix
  2950 operator BIT and the bit datatype with constructors B0 and B1 have
  2951 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2952 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2953 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2954 accordingly.
  2955 
  2956 * Theory Nat: definition of <= and < on natural numbers no longer
  2957 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2958 le_def and less_def have disappeared.  Consider lemmas not_less
  2959 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2960 
  2961 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2962 (whose purpose mainly is for various fold_set functionals) have been
  2963 abandoned in favor of the existing algebraic classes
  2964 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2965 lower_semilattice (resp. upper_semilattice) and linorder.
  2966 INCOMPATIBILITY.
  2967 
  2968 * Theory Transitive_Closure: induct and cases rules now declare proper
  2969 case_names ("base" and "step").  INCOMPATIBILITY.
  2970 
  2971 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2972 lattices.  The form set-specific version is available as
  2973 Inductive.lfp_ordinal_induct_set.
  2974 
  2975 * Renamed theorems "power.simps" to "power_int.simps".
  2976 INCOMPATIBILITY.
  2977 
  2978 * Class semiring_div provides basic abstract properties of semirings
  2979 with division and modulo operations.  Subsumes former class dvd_mod.
  2980 
  2981 * Merged theories IntDef, Numeral and IntArith into unified theory
  2982 Int.  INCOMPATIBILITY.
  2983 
  2984 * Theory Library/Code_Index: type "index" now represents natural
  2985 numbers rather than integers.  INCOMPATIBILITY.
  2986 
  2987 * New class "uminus" with operation "uminus" (split of from class
  2988 "minus" which now only has operation "minus", binary).
  2989 INCOMPATIBILITY.
  2990 
  2991 * Constants "card", "internal_split", "option_map" now with authentic
  2992 syntax.  INCOMPATIBILITY.
  2993 
  2994 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2995 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2996 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2997 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2998 Sup_set_def, le_def, less_def, option_map_def now with object
  2999 equality.  INCOMPATIBILITY.
  3000 
  3001 * Records. Removed K_record, and replaced it by pure lambda term
  3002 %x. c. The simplifier setup is now more robust against eta expansion.
  3003 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3004 
  3005 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3006 
  3007 * Library/ListVector: new theory of arithmetic vector operations.
  3008 
  3009 * Library/Order_Relation: new theory of various orderings as sets of
  3010 pairs.  Defines preorders, partial orders, linear orders and
  3011 well-orders on sets and on types.
  3012 
  3013 
  3014 *** ZF ***
  3015 
  3016 * Renamed some theories to allow to loading both ZF and HOL in the
  3017 same session:
  3018 
  3019   Datatype  -> Datatype_ZF
  3020   Inductive -> Inductive_ZF
  3021   Int       -> Int_ZF
  3022   IntDiv    -> IntDiv_ZF
  3023   Nat       -> Nat_ZF
  3024   List      -> List_ZF
  3025   Main      -> Main_ZF
  3026 
  3027 INCOMPATIBILITY: ZF theories that import individual theories below
  3028 Main might need to be adapted.  Regular theory Main is still
  3029 available, as trivial extension of Main_ZF.
  3030 
  3031 
  3032 *** ML ***
  3033 
  3034 * ML within Isar: antiquotation @{const name} or @{const
  3035 name(typargs)} produces statically-checked Const term.
  3036 
  3037 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3038 (of the same name).  Removed obsolete print command.
  3039 
  3040 * Removed obsolete "use_legacy_bindings" function.
  3041 
  3042 * The ``print mode'' is now a thread-local value derived from a global
  3043 template (the former print_mode reference), thus access becomes
  3044 non-critical.  The global print_mode reference is for session
  3045 management only; user-code should use print_mode_value,
  3046 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3047 
  3048 * Functions system/system_out provide a robust way to invoke external
  3049 shell commands, with propagation of interrupts (requires Poly/ML
  3050 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3051 
  3052 
  3053 *** System ***
  3054 
  3055 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3056 in accordance with Proof General 3.7, which prefers GNU emacs.
  3057 
  3058 * isatool tty runs Isabelle process with plain tty interaction;
  3059 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3060 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3061 
  3062 * isatool browser now works with Cygwin as well, using general
  3063 "javapath" function defined in Isabelle process environment.
  3064 
  3065 * YXML notation provides a simple and efficient alternative to
  3066 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3067 isatool yxml as described in the Isabelle system manual.
  3068 
  3069 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3070 provides general wrapper for managing an Isabelle process in a robust
  3071 fashion, with ``cooked'' output from stdin/stderr.
  3072 
  3073 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3074 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3075 
  3076 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3077 way of changing the user's settings is via
  3078 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3079 script.
  3080 
  3081 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3082 cores of the underlying machine, which is a good starting point for
  3083 optimal performance tuning.  The corresponding usedir option -M allows
  3084 "max" as an alias for "0".  WARNING: does not work on certain versions
  3085 of Mac OS (with Poly/ML 5.1).
  3086 
  3087 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3088 adverse effect of Isabelle flooding interactive front-ends (notably
  3089 ProofGeneral / XEmacs).
  3090 
  3091 
  3092 
  3093 New in Isabelle2007 (November 2007)
  3094 -----------------------------------
  3095 
  3096 *** General ***
  3097 
  3098 * More uniform information about legacy features, notably a
  3099 warning/error of "Legacy feature: ...", depending on the state of the
  3100 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3101 legacy features will disappear eventually.
  3102 
  3103 * Theory syntax: the header format ``theory A = B + C:'' has been
  3104 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3105 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3106 
  3107 * Theory syntax: the old non-Isar theory file format has been
  3108 discontinued altogether.  Note that ML proof scripts may still be used
  3109 with Isar theories; migration is usually quite simple with the ML
  3110 function use_legacy_bindings.  INCOMPATIBILITY.
  3111 
  3112 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3113 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3114 quotes.
  3115 
  3116 * Theory loader: be more serious about observing the static theory
  3117 header specifications (including optional directories), but not the
  3118 accidental file locations of previously successful loads.  The strict
  3119 update policy of former update_thy is now already performed by
  3120 use_thy, so the former has been removed; use_thys updates several
  3121 theories simultaneously, just as 'imports' within a theory header
  3122 specification, but without merging the results.  Potential
  3123 INCOMPATIBILITY: may need to refine theory headers and commands
  3124 ROOT.ML which depend on load order.
  3125 
  3126 * Theory loader: optional support for content-based file
  3127 identification, instead of the traditional scheme of full physical
  3128 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3129 (cf. the system manual).  The new scheme allows to work with
  3130 non-finished theories in persistent session images, such that source
  3131 files may be moved later on without requiring reloads.
  3132 
  3133 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3134 file (with the same base name as the theory) are considered a legacy
  3135 feature, which will disappear eventually. Even now, the theory loader
  3136 no longer maintains dependencies on such files.
  3137 
  3138 * Syntax: the scope for resolving ambiguities via type-inference is
  3139 now limited to individual terms, instead of whole simultaneous
  3140 specifications as before. This greatly reduces the complexity of the
  3141 syntax module and improves flexibility by separating parsing and
  3142 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3143 'fixes' etc.) are required in rare situations.
  3144 
  3145 * Syntax: constants introduced by new-style packages ('definition',
  3146 'abbreviation' etc.) are passed through the syntax module in
  3147 ``authentic mode''. This means that associated mixfix annotations
  3148 really stick to such constants, independently of potential name space
  3149 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3150 trees are represented slightly differently, may need to adapt syntax
  3151 translations accordingly. Use CONST marker in 'translations' and
  3152 @{const_syntax} antiquotation in 'parse_translation' etc.
  3153 
  3154 * Legacy goal package: reduced interface to the bare minimum required
  3155 to keep existing proof scripts running.  Most other user-level
  3156 functions are now part of the OldGoals structure, which is *not* open
  3157 by default (consider isatool expandshort before open OldGoals).
  3158 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3159 these tend to cause confusion about the actual goal (!) context being
  3160 used here, which is not necessarily the same as the_context().
  3161 
  3162 * Command 'find_theorems': supports "*" wild-card in "name:"
  3163 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3164 support a specific search form (see ProofGeneral/CHANGES).
  3165 
  3166 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3167 by default, which means that "prems" (and also "fixed variables") are
  3168 suppressed from proof state output.  Note that the ProofGeneral
  3169 settings mechanism allows to change and save options persistently, but
  3170 older versions of Isabelle will fail to start up if a negative prems
  3171 limit is imposed.
  3172 
  3173 * Local theory targets may be specified by non-nested blocks of
  3174 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3175 contain definitions, theorems etc., including any derived mechanism
  3176 that has been implemented on top of these primitives.  This concept
  3177 generalizes the existing ``theorem (in ...)'' towards more versatility
  3178 and scalability.
  3179 
  3180 * Proof General interface: proper undo of final 'end' command;
  3181 discontinued Isabelle/classic mode (ML proof scripts).
  3182 
  3183 
  3184 *** Document preparation ***
  3185 
  3186 * Added antiquotation @{theory name} which prints the given name,
  3187 after checking that it refers to a valid ancestor theory in the
  3188 current context.
  3189 
  3190 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3191 check the given source text as ML type/structure, printing verbatim.
  3192 
  3193 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3194 "c args == rhs" given in the current context.  (Any number of
  3195 arguments may be given on the LHS.)
  3196 
  3197 
  3198 *** Pure ***
  3199 
  3200 * The 'class' package offers a combination of axclass and locale to
  3201 achieve Haskell-like type classes in Isabelle.  Definitions and
  3202 theorems within a class context produce both relative results (with
  3203 implicit parameters according to the locale context), and polymorphic
  3204 constants with qualified polymorphism (according to the class
  3205 context).  Within the body context of a 'class' target, a separate
  3206 syntax layer ("user space type system") takes care of converting
  3207 between global polymorphic consts and internal locale representation.
  3208 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3209 "isatool doc classes" provides a tutorial.
  3210 
  3211 * Generic code generator framework allows to generate executable
  3212 code for ML and Haskell (including Isabelle classes).  A short usage
  3213 sketch:
  3214 
  3215     internal compilation:
  3216         export_code <list of constants (term syntax)> in SML
  3217     writing SML code to a file:
  3218         export_code <list of constants (term syntax)> in SML <filename>
  3219     writing OCaml code to a file:
  3220         export_code <list of constants (term syntax)> in OCaml <filename>
  3221     writing Haskell code to a bunch of files:
  3222         export_code <list of constants (term syntax)> in Haskell <filename>
  3223 
  3224     evaluating closed propositions to True/False using code generation:
  3225         method ``eval''
  3226 
  3227 Reasonable default setup of framework in HOL.
  3228 
  3229 Theorem attributs for selecting and transforming function equations theorems:
  3230 
  3231     [code fun]:        select a theorem as function equation for a specific constant
  3232     [code fun del]:    deselect a theorem as function equation for a specific constant
  3233     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3234     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3235 
  3236 User-defined serializations (target in {SML, OCaml, Haskell}):
  3237 
  3238     code_const <and-list of constants (term syntax)>
  3239       {(target) <and-list of const target syntax>}+
  3240 
  3241     code_type <and-list of type constructors>
  3242       {(target) <and-list of type target syntax>}+
  3243 
  3244     code_instance <and-list of instances>
  3245       {(target)}+
  3246         where instance ::= <type constructor> :: <class>
  3247 
  3248     code_class <and_list of classes>
  3249       {(target) <and-list of class target syntax>}+
  3250         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3251 
  3252 code_instance and code_class only are effective to target Haskell.
  3253 
  3254 For example usage see src/HOL/ex/Codegenerator.thy and
  3255 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3256 generation from Isabelle/HOL theories is available via "isatool doc
  3257 codegen".
  3258 
  3259 * Code generator: consts in 'consts_code' Isar commands are now
  3260 referred to by usual term syntax (including optional type
  3261 annotations).
  3262 
  3263 * Command 'no_translations' removes translation rules from theory
  3264 syntax.
  3265 
  3266 * Overloaded definitions are now actually checked for acyclic
  3267 dependencies.  The overloading scheme is slightly more general than
  3268 that of Haskell98, although Isabelle does not demand an exact
  3269 correspondence to type class and instance declarations.
  3270 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3271 exotic versions of overloading -- at the discretion of the user!
  3272 
  3273 Polymorphic constants are represented via type arguments, i.e. the
  3274 instantiation that matches an instance against the most general
  3275 declaration given in the signature.  For example, with the declaration
  3276 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3277 as c(nat).  Overloading is essentially simultaneous structural
  3278 recursion over such type arguments.  Incomplete specification patterns
  3279 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3280 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3281 Command 'print_theory' outputs the normalized system of recursive
  3282 equations, see section "definitions".
  3283 
  3284 * Configuration options are maintained within the theory or proof
  3285 context (with name and type bool/int/string), providing a very simple
  3286 interface to a poor-man's version of general context data.  Tools may
  3287 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3288 these values using Config.get etc.  Users may change options via an
  3289 associated attribute of the same name.  This form of context
  3290 declaration works particularly well with commands 'declare' or
  3291 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3292 very easy to avoid global references, which would not observe Isar
  3293 toplevel undo/redo and fail to work with multithreading.
  3294 
  3295 Various global ML references of Pure and HOL have been turned into
  3296 configuration options:
  3297 
  3298   Unify.search_bound		unify_search_bound
  3299   Unify.trace_bound		unify_trace_bound
  3300   Unify.trace_simp		unify_trace_simp
  3301   Unify.trace_types		unify_trace_types
  3302   Simplifier.simp_depth_limit	simp_depth_limit
  3303   Blast.depth_limit		blast_depth_limit
  3304   DatatypeProp.dtK		datatype_distinctness_limit
  3305   fast_arith_neq_limit  	fast_arith_neq_limit
  3306   fast_arith_split_limit	fast_arith_split_limit
  3307 
  3308 * Named collections of theorems may be easily installed as context
  3309 data using the functor NamedThmsFun (see also
  3310 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3311 attributes; there is also a toplevel print command.  This facility is
  3312 just a common case of general context data, which is the preferred way
  3313 for anything more complex than just a list of facts in canonical
  3314 order.
  3315 
  3316 * Isar: command 'declaration' augments a local theory by generic
  3317 declaration functions written in ML.  This enables arbitrary content
  3318 being added to the context, depending on a morphism that tells the
  3319 difference of the original declaration context wrt. the application
  3320 context encountered later on.
  3321 
  3322 * Isar: proper interfaces for simplification procedures.  Command
  3323 'simproc_setup' declares named simprocs (with match patterns, and body
  3324 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3325 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3326 
  3327 * Isar: an extra pair of brackets around attribute declarations
  3328 abbreviates a theorem reference involving an internal dummy fact,
  3329 which will be ignored later --- only the effect of the attribute on
  3330 the background context will persist.  This form of in-place
  3331 declarations is particularly useful with commands like 'declare' and
  3332 'using', for example ``have A using [[simproc a]] by simp''.
  3333 
  3334 * Isar: method "assumption" (and implicit closing of subproofs) now
  3335 takes simple non-atomic goal assumptions into account: after applying
  3336 an assumption as a rule the resulting subgoals are solved by atomic
  3337 assumption steps.  This is particularly useful to finish 'obtain'
  3338 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3339 without referring to the original premise "!!x. P x ==> thesis" in the
  3340 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3341 more permissive.
  3342 
  3343 * Isar: implicit use of prems from the Isar proof context is
  3344 considered a legacy feature.  Common applications like ``have A .''
  3345 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3346 referencing facts explicitly here improves readability and
  3347 maintainability of proof texts.
  3348 
  3349 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3350 the obtained context from the course of reasoning!  For example:
  3351 
  3352   assume "EX x y. A x & B y"   -- "any previous fact"
  3353   then guess x and y by clarify
  3354 
  3355 This technique is potentially adventurous, depending on the facts and
  3356 proof tools being involved here.
  3357 
  3358 * Isar: known facts from the proof context may be specified as literal
  3359 propositions, using ASCII back-quote syntax.  This works wherever
  3360 named facts used to be allowed so far, in proof commands, proof
  3361 methods, attributes etc.  Literal facts are retrieved from the context
  3362 according to unification of type and term parameters.  For example,
  3363 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3364 theorems in the current context, then these are valid literal facts:
  3365 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3366 
  3367 There is also a proof method "fact" which does the same composition
  3368 for explicit goal states, e.g. the following proof texts coincide with
  3369 certain special cases of literal facts:
  3370 
  3371   have "A" by fact                 ==  note `A`
  3372   have "A ==> B" by fact           ==  note `A ==> B`
  3373   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3374   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3375 
  3376 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3377 outer syntax.  Thus symbolic identifiers may be used without
  3378 additional white space in declarations like this: ``assume *: A''.
  3379 
  3380 * Isar: 'print_facts' prints all local facts of the current context,
  3381 both named and unnamed ones.
  3382 
  3383 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3384 
  3385   def x == "t" and y == "u"
  3386 
  3387 * Isar: added command 'unfolding', which is structurally similar to
  3388 'using', but affects both the goal state and facts by unfolding given
  3389 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3390 'unfolded' attribute may be replaced by first-class proof text.
  3391 
  3392 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3393 and command 'unfolding' now all support object-level equalities
  3394 (potentially conditional).  The underlying notion of rewrite rule is
  3395 analogous to the 'rule_format' attribute, but *not* that of the
  3396 Simplifier (which is usually more generous).
  3397 
  3398 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3399 premises of a theorem by n. Useful in conjunction with drule.
  3400 
  3401 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3402 method expression within a sandbox consisting of the first N
  3403 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3404 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3405 simplifies all new goals that emerge from applying rule foo to the
  3406 originally first one.
  3407 
  3408 * Isar: schematic goals are no longer restricted to higher-order
  3409 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3410 expected.
  3411 
  3412 * Isar: the conclusion of a long theorem statement is now either
  3413 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3414 (essentially a disjunction of cases with local parameters and
  3415 assumptions).  The latter allows to express general elimination rules
  3416 adequately; in this notation common elimination rules look like this:
  3417 
  3418   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3419     assumes "EX x. P x"
  3420     obtains x where "P x"
  3421 
  3422   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3423     assumes "A & B"
  3424     obtains A and B
  3425 
  3426   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3427     assumes "A | B"
  3428     obtains
  3429       A
  3430     | B
  3431 
  3432 The subsequent classical rules even refer to the formal "thesis"
  3433 explicitly:
  3434 
  3435   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3436     obtains "~ thesis"
  3437 
  3438   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3439     obtains "thesis ==> something"
  3440 
  3441 The actual proof of an 'obtains' statement is analogous to that of the
  3442 Isar proof element 'obtain', only that there may be several cases.
  3443 Optional case names may be specified in parentheses; these will be
  3444 available both in the present proof and as annotations in the
  3445 resulting rule, for later use with the 'cases' method (cf. attribute
  3446 case_names).
  3447 
  3448 * Isar: the assumptions of a long theorem statement are available as
  3449 "assms" fact in the proof context.  This is more appropriate than the
  3450 (historical) "prems", which refers to all assumptions of the current
  3451 context, including those from the target locale, proof body etc.
  3452 
  3453 * Isar: 'print_statement' prints theorems from the current theory or
  3454 proof context in long statement form, according to the syntax of a
  3455 top-level lemma.
  3456 
  3457 * Isar: 'obtain' takes an optional case name for the local context
  3458 introduction rule (default "that").
  3459 
  3460 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3461 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3462 to occur.
  3463 
  3464 * Pure: syntax "CONST name" produces a fully internalized constant
  3465 according to the current context.  This is particularly useful for
  3466 syntax translations that should refer to internal constant
  3467 representations independently of name spaces.
  3468 
  3469 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3470 instead of "FOO ". This allows multiple binder declarations to coexist
  3471 in the same context.  INCOMPATIBILITY.
  3472 
  3473 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3474 primitive that also works in a locale context (both for constants and
  3475 fixed variables). Type declaration and internal syntactic representation
  3476 of given constants retrieved from the context. Likewise, the
  3477 'no_notation' command allows to remove given syntax annotations from the
  3478 current context.
  3479 
  3480 * Isar/locales: new derived specification elements 'axiomatization',
  3481 'definition', 'abbreviation', which support type-inference, admit
  3482 object-level specifications (equality, equivalence).  See also the
  3483 isar-ref manual.  Examples:
  3484 
  3485   axiomatization
  3486     eq  (infix "===" 50) where
  3487     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3488 
  3489   definition "f x y = x + y + 1"
  3490   definition g where "g x = f x x"
  3491 
  3492   abbreviation
  3493     neq  (infix "=!=" 50) where
  3494     "x =!= y == ~ (x === y)"
  3495 
  3496 These specifications may be also used in a locale context.  Then the
  3497 constants being introduced depend on certain fixed parameters, and the
  3498 constant name is qualified by the locale base name.  An internal
  3499 abbreviation takes care for convenient input and output, making the
  3500 parameters implicit and using the original short name.  See also
  3501 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3502 entities from a monomorphic theory.
  3503 
  3504 Presently, abbreviations are only available 'in' a target locale, but
  3505 not inherited by general import expressions.  Also note that
  3506 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3507 'translations' in common applications.  The "no_abbrevs" print mode
  3508 prevents folding of abbreviations in term output.
  3509 
  3510 Concrete syntax is attached to specified constants in internal form,
  3511 independently of name spaces.  The parse tree representation is
  3512 slightly different -- use 'notation' instead of raw 'syntax', and
  3513 'translations' with explicit "CONST" markup to accommodate this.
  3514 
  3515 * Pure/Isar: unified syntax for new-style specification mechanisms
  3516 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3517 full type inference and dummy patterns ("_").  For example:
  3518 
  3519   definition "K x _ = x"
  3520 
  3521   inductive conj for A B
  3522   where "A ==> B ==> conj A B"
  3523 
  3524 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3525 the current context.  Print mode "no_abbrevs" prevents inversion of
  3526 abbreviations on output.
  3527 
  3528 * Isar/locales: improved parameter handling: use of locales "var" and
  3529 "struct" no longer necessary; - parameter renamings are no longer
  3530 required to be injective.  For example, this allows to define
  3531 endomorphisms as locale endom = homom mult mult h.
  3532 
  3533 * Isar/locales: changed the way locales with predicates are defined.
  3534 Instead of accumulating the specification, the imported expression is
  3535 now an interpretation.  INCOMPATIBILITY: different normal form of
  3536 locale expressions.  In particular, in interpretations of locales with
  3537 predicates, goals repesenting already interpreted fragments are not
  3538 removed automatically.  Use methods `intro_locales' and
  3539 `unfold_locales'; see below.
  3540 
  3541 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3542 provide backward reasoning on locales predicates.  The methods are
  3543 aware of interpretations and discharge corresponding goals.
  3544 `intro_locales' is less aggressive then `unfold_locales' and does not
  3545 unfold predicates to assumptions.
  3546 
  3547 * Isar/locales: the order in which locale fragments are accumulated
  3548 has changed.  This enables to override declarations from fragments due
  3549 to interpretations -- for example, unwanted simp rules.
  3550 
  3551 * Isar/locales: interpretation in theories and proof contexts has been
  3552 extended.  One may now specify (and prove) equations, which are
  3553 unfolded in interpreted theorems.  This is useful for replacing
  3554 defined concepts (constants depending on locale parameters) by
  3555 concepts already existing in the target context.  Example:
  3556 
  3557   interpretation partial_order ["op <= :: [int, int] => bool"]
  3558     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3559 
  3560 Typically, the constant `partial_order.less' is created by a
  3561 definition specification element in the context of locale
  3562 partial_order.
  3563 
  3564 * Method "induct": improved internal context management to support
  3565 local fixes and defines on-the-fly. Thus explicit meta-level
  3566 connectives !!  and ==> are rarely required anymore in inductive goals
  3567 (using object-logic connectives for this purpose has been long
  3568 obsolete anyway). Common proof patterns are explained in
  3569 src/HOL/Induct/Common_Patterns.thy, see also
  3570 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3571 examples.
  3572 
  3573 * Method "induct": improved handling of simultaneous goals. Instead of
  3574 introducing object-level conjunction, the statement is now split into
  3575 several conclusions, while the corresponding symbolic cases are nested
  3576 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3577 see src/HOL/Induct/Common_Patterns.thy, for example.
  3578 
  3579 * Method "induct": mutual induction rules are now specified as a list
  3580 of rule sharing the same induction cases. HOL packages usually provide
  3581 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3582 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3583 mutual induction rules differently, i.e. like this:
  3584 
  3585   (induct rule: foo_bar.inducts)
  3586   (induct set: foo bar)
  3587   (induct pred: foo bar)
  3588   (induct type: foo bar)
  3589 
  3590 The ML function ProjectRule.projections turns old-style rules into the
  3591 new format.
  3592 
  3593 * Method "coinduct": dual of induction, see
  3594 src/HOL/Library/Coinductive_List.thy for various examples.
  3595 
  3596 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3597 considered a legacy feature.
  3598 
  3599 * Attribute "symmetric" produces result with standardized schematic
  3600 variables (index 0).  Potential INCOMPATIBILITY.
  3601 
  3602 * Simplifier: by default the simplifier trace only shows top level
  3603 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3604 default. Thus there is less danger of being flooded by the trace. The
  3605 trace indicates where parts have been suppressed.
  3606   
  3607 * Provers/classical: removed obsolete classical version of elim_format
  3608 attribute; classical elim/dest rules are now treated uniformly when
  3609 manipulating the claset.
  3610 
  3611 * Provers/classical: stricter checks to ensure that supplied intro,
  3612 dest and elim rules are well-formed; dest and elim rules must have at
  3613 least one premise.
  3614 
  3615 * Provers/classical: attributes dest/elim/intro take an optional
  3616 weight argument for the rule (just as the Pure versions).  Weights are
  3617 ignored by automated tools, but determine the search order of single
  3618 rule steps.
  3619 
  3620 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3621 where the body does not mention the bound variable.  Note that dummy
  3622 patterns implicitly depend on their context of bounds, which makes
  3623 "{_. _}" match any set comprehension as expected.  Potential
  3624 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3625 constant "_idtdummy" in the binding position.
  3626 
  3627 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3628 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3629 for example "A -> B" => "Pi A (%_. B)".
  3630 
  3631 * Pure: 'class_deps' command visualizes the subclass relation, using
  3632 the graph browser tool.
  3633 
  3634 * Pure: 'print_theory' now suppresses certain internal declarations by
  3635 default; use '!' option for full details.
  3636 
  3637 
  3638 *** HOL ***
  3639 
  3640 * Method "metis" proves goals by applying the Metis general-purpose
  3641 resolution prover (see also http://gilith.com/software/metis/).
  3642 Examples are in the directory MetisExamples.  WARNING: the
  3643 Isabelle/HOL-Metis integration does not yet work properly with
  3644 multi-threading.
  3645   
  3646 * Command 'sledgehammer' invokes external automatic theorem provers as
  3647 background processes.  It generates calls to the "metis" method if
  3648 successful. These can be pasted into the proof.  Users do not have to
  3649 wait for the automatic provers to return.  WARNING: does not really
  3650 work with multi-threading.
  3651 
  3652 * New "auto_quickcheck" feature tests outermost goal statements for
  3653 potential counter-examples.  Controlled by ML references
  3654 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3655 5000 milliseconds).  Fails silently if statements is outside of
  3656 executable fragment, or any other codgenerator problem occurs.
  3657 
  3658 * New constant "undefined" with axiom "undefined x = undefined".
  3659 
  3660 * Added class "HOL.eq", allowing for code generation with polymorphic
  3661 equality.
  3662 
  3663 * Some renaming of class constants due to canonical name prefixing in
  3664 the new 'class' package:
  3665 
  3666     HOL.abs ~> HOL.abs_class.abs
  3667     HOL.divide ~> HOL.divide_class.divide
  3668     0 ~> HOL.zero_class.zero
  3669     1 ~> HOL.one_class.one
  3670     op + ~> HOL.plus_class.plus
  3671     op - ~> HOL.minus_class.minus
  3672     uminus ~> HOL.minus_class.uminus
  3673     op * ~> HOL.times_class.times
  3674     op < ~> HOL.ord_class.less
  3675     op <= > HOL.ord_class.less_eq
  3676     Nat.power ~> Power.power_class.power
  3677     Nat.size ~> Nat.size_class.size
  3678     Numeral.number_of ~> Numeral.number_class.number_of
  3679     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3680     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3681     Orderings.min ~> Orderings.ord_class.min
  3682     Orderings.max ~> Orderings.ord_class.max
  3683     Divides.op div ~> Divides.div_class.div
  3684     Divides.op mod ~> Divides.div_class.mod
  3685     Divides.op dvd ~> Divides.div_class.dvd
  3686 
  3687 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3688 
  3689 a) User-defined constants using any of the names "plus", "minus",
  3690 "times", "less" or "less_eq". The standard syntax translations for
  3691 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3692 names.
  3693 
  3694 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3695 INCOMPATIBILITY: use more specific names.
  3696 
  3697 c) Permutative equations (e.g. "a + b = b + a")
  3698 Since the change of names also changes the order of terms, permutative
  3699 rewrite rules may get applied in a different order. Experience shows
  3700 that this is rarely the case (only two adaptions in the whole Isabelle
  3701 distribution).  INCOMPATIBILITY: rewrite proofs
  3702 
  3703 d) ML code directly refering to constant names
  3704 This in general only affects hand-written proof tactics, simprocs and
  3705 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3706 Consider using @{const_name} antiquotation.
  3707 
  3708 * New class "default" with associated constant "default".
  3709 
  3710 * Function "sgn" is now overloaded and available on int, real, complex
  3711 (and other numeric types), using class "sgn".  Two possible defs of
  3712 sgn are given as equational assumptions in the classes sgn_if and
  3713 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3714 INCOMPATIBILITY.
  3715 
  3716 * Locale "partial_order" now unified with class "order" (cf. theory
  3717 Orderings), added parameter "less".  INCOMPATIBILITY.
  3718 
  3719 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3720 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3721 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3722 
  3723 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3724 changed order of proof goals in instance proofs.
  3725 
  3726 * The transitivity reasoner for partial and linear orders is set up
  3727 for classes "order" and "linorder".  Instances of the reasoner are available
  3728 in all contexts importing or interpreting the corresponding locales.
  3729 Method "order" invokes the reasoner separately; the reasoner
  3730 is also integrated with the Simplifier as a solver.  Diagnostic
  3731 command 'print_orders' shows the available instances of the reasoner
  3732 in the current context.
  3733 
  3734 * Localized monotonicity predicate in theory "Orderings"; integrated
  3735 lemmas max_of_mono and min_of_mono with this predicate.
  3736 INCOMPATIBILITY.
  3737 
  3738 * Formulation of theorem "dense" changed slightly due to integration
  3739 with new class dense_linear_order.
  3740 
  3741 * Uniform lattice theory development in HOL.
  3742 
  3743     constants "meet" and "join" now named "inf" and "sup"
  3744     constant "Meet" now named "Inf"
  3745 
  3746     classes "meet_semilorder" and "join_semilorder" now named
  3747       "lower_semilattice" and "upper_semilattice"
  3748     class "lorder" now named "lattice"
  3749     class "comp_lat" now named "complete_lattice"
  3750 
  3751     Instantiation of lattice classes allows explicit definitions
  3752     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3753 
  3754   INCOMPATIBILITY.  Theorem renames:
  3755 
  3756     meet_left_le            ~> inf_le1
  3757     meet_right_le           ~> inf_le2
  3758     join_left_le            ~> sup_ge1
  3759     join_right_le           ~> sup_ge2
  3760     meet_join_le            ~> inf_sup_ord
  3761     le_meetI                ~> le_infI
  3762     join_leI                ~> le_supI
  3763     le_meet                 ~> le_inf_iff
  3764     le_join                 ~> ge_sup_conv
  3765     meet_idempotent         ~> inf_idem
  3766     join_idempotent         ~> sup_idem
  3767     meet_comm               ~> inf_commute
  3768     join_comm               ~> sup_commute
  3769     meet_leI1               ~> le_infI1
  3770     meet_leI2               ~> le_infI2
  3771     le_joinI1               ~> le_supI1
  3772     le_joinI2               ~> le_supI2
  3773     meet_assoc              ~> inf_assoc
  3774     join_assoc              ~> sup_assoc
  3775     meet_left_comm          ~> inf_left_commute
  3776     meet_left_idempotent    ~> inf_left_idem
  3777     join_left_comm          ~> sup_left_commute
  3778     join_left_idempotent    ~> sup_left_idem
  3779     meet_aci                ~> inf_aci
  3780     join_aci                ~> sup_aci
  3781     le_def_meet             ~> le_iff_inf
  3782     le_def_join             ~> le_iff_sup
  3783     join_absorp2            ~> sup_absorb2
  3784     join_absorp1            ~> sup_absorb1
  3785     meet_absorp1            ~> inf_absorb1
  3786     meet_absorp2            ~> inf_absorb2
  3787     meet_join_absorp        ~> inf_sup_absorb
  3788     join_meet_absorp        ~> sup_inf_absorb
  3789     distrib_join_le         ~> distrib_sup_le
  3790     distrib_meet_le         ~> distrib_inf_le
  3791 
  3792     add_meet_distrib_left   ~> add_inf_distrib_left
  3793     add_join_distrib_left   ~> add_sup_distrib_left
  3794     is_join_neg_meet        ~> is_join_neg_inf
  3795     is_meet_neg_join        ~> is_meet_neg_sup
  3796     add_meet_distrib_right  ~> add_inf_distrib_right
  3797     add_join_distrib_right  ~> add_sup_distrib_right
  3798     add_meet_join_distribs  ~> add_sup_inf_distribs
  3799     join_eq_neg_meet        ~> sup_eq_neg_inf
  3800     meet_eq_neg_join        ~> inf_eq_neg_sup
  3801     add_eq_meet_join        ~> add_eq_inf_sup
  3802     meet_0_imp_0            ~> inf_0_imp_0
  3803     join_0_imp_0            ~> sup_0_imp_0
  3804     meet_0_eq_0             ~> inf_0_eq_0
  3805     join_0_eq_0             ~> sup_0_eq_0
  3806     neg_meet_eq_join        ~> neg_inf_eq_sup
  3807     neg_join_eq_meet        ~> neg_sup_eq_inf
  3808     join_eq_if              ~> sup_eq_if
  3809 
  3810     mono_meet               ~> mono_inf
  3811     mono_join               ~> mono_sup
  3812     meet_bool_eq            ~> inf_bool_eq
  3813     join_bool_eq            ~> sup_bool_eq
  3814     meet_fun_eq             ~> inf_fun_eq
  3815     join_fun_eq             ~> sup_fun_eq
  3816     meet_set_eq             ~> inf_set_eq
  3817     join_set_eq             ~> sup_set_eq
  3818     meet1_iff               ~> inf1_iff
  3819     meet2_iff               ~> inf2_iff
  3820     meet1I                  ~> inf1I
  3821     meet2I                  ~> inf2I
  3822     meet1D1                 ~> inf1D1
  3823     meet2D1                 ~> inf2D1
  3824     meet1D2                 ~> inf1D2
  3825     meet2D2                 ~> inf2D2
  3826     meet1E                  ~> inf1E
  3827     meet2E                  ~> inf2E
  3828     join1_iff               ~> sup1_iff
  3829     join2_iff               ~> sup2_iff
  3830     join1I1                 ~> sup1I1
  3831     join2I1                 ~> sup2I1
  3832     join1I1                 ~> sup1I1
  3833     join2I2                 ~> sup1I2
  3834     join1CI                 ~> sup1CI
  3835     join2CI                 ~> sup2CI
  3836     join1E                  ~> sup1E
  3837     join2E                  ~> sup2E
  3838 
  3839     is_meet_Meet            ~> is_meet_Inf
  3840     Meet_bool_def           ~> Inf_bool_def
  3841     Meet_fun_def            ~> Inf_fun_def
  3842     Meet_greatest           ~> Inf_greatest
  3843     Meet_lower              ~> Inf_lower
  3844     Meet_set_def            ~> Inf_set_def
  3845 
  3846     Sup_def                 ~> Sup_Inf
  3847     Sup_bool_eq             ~> Sup_bool_def
  3848     Sup_fun_eq              ~> Sup_fun_def
  3849     Sup_set_eq              ~> Sup_set_def
  3850 
  3851     listsp_meetI            ~> listsp_infI
  3852     listsp_meet_eq          ~> listsp_inf_eq
  3853 
  3854     meet_min                ~> inf_min
  3855     join_max                ~> sup_max
  3856 
  3857 * Added syntactic class "size"; overloaded constant "size" now has
  3858 type "'a::size ==> bool"
  3859 
  3860 * Internal reorganisation of `size' of datatypes: size theorems
  3861 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3862 simplification rules by default!); theorems "prod.size" now named
  3863 "*.size".
  3864 
  3865 * Class "div" now inherits from class "times" rather than "type".
  3866 INCOMPATIBILITY.
  3867 
  3868 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3869 Linorder etc.  have disappeared; operations defined in terms of
  3870 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3871 
  3872 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3873 
  3874 * HOL-Word: New extensive library and type for generic, fixed size
  3875 machine words, with arithemtic, bit-wise, shifting and rotating
  3876 operations, reflection into int, nat, and bool lists, automation for
  3877 linear arithmetic (by automatic reflection into nat or int), including
  3878 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3879 arithmetic type classes, supporting automatic simplification of
  3880 numerals on all operations.
  3881 
  3882 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3883 
  3884 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3885 
  3886 * Code generator library theories:
  3887   - Code_Integer represents HOL integers by big integer literals in target
  3888     languages.
  3889   - Code_Char represents HOL characters by character literals in target
  3890     languages.
  3891   - Code_Char_chr like Code_Char, but also offers treatment of character
  3892     codes; includes Code_Integer.
  3893   - Executable_Set allows to generate code for finite sets using lists.
  3894   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3895     denominator).
  3896   - Executable_Real implements a subset of real numbers, namly those
  3897     representable by rational numbers.
  3898   - Efficient_Nat implements natural numbers by integers, which in general will
  3899     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3900     includes Code_Integer.
  3901   - Code_Index provides an additional datatype index which is mapped to
  3902     target-language built-in integers.
  3903   - Code_Message provides an additional datatype message_string which is isomorphic to
  3904     strings; messages are mapped to target-language strings.
  3905 
  3906 * New package for inductive predicates
  3907 
  3908   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3909 
  3910     inductive
  3911       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3912       for z_1 :: U_1 and ... and z_n :: U_m
  3913     where
  3914       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3915     | ...
  3916 
  3917   with full support for type-inference, rather than
  3918 
  3919     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3920 
  3921     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3922     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3923 
  3924     inductive "s z_1 ... z_m"
  3925     intros
  3926       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3927       ...
  3928 
  3929   For backward compatibility, there is a wrapper allowing inductive
  3930   sets to be defined with the new package via
  3931 
  3932     inductive_set
  3933       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3934       for z_1 :: U_1 and ... and z_n :: U_m
  3935     where
  3936       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3937     | ...
  3938 
  3939   or
  3940 
  3941     inductive_set
  3942       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3943       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3944       for z_1 :: U_1 and ... and z_n :: U_m
  3945     where
  3946       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3947     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3948     | ...
  3949 
  3950   if the additional syntax "p ..." is required.
  3951 
  3952   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3953   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3954 
  3955   INCOMPATIBILITIES:
  3956 
  3957   - Since declaration and definition of inductive sets or predicates
  3958     is no longer separated, abbreviations involving the newly
  3959     introduced sets or predicates must be specified together with the
  3960     introduction rules after the 'where' keyword (see above), rather
  3961     than before the actual inductive definition.
  3962 
  3963   - The variables in induction and elimination rules are now
  3964     quantified in the order of their occurrence in the introduction
  3965     rules, rather than in alphabetical order. Since this may break
  3966     some proofs, these proofs either have to be repaired, e.g. by
  3967     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3968     statements of the form
  3969 
  3970       case (rule_i a_i_1 ... a_i_{k_i})
  3971 
  3972     or the old order of quantification has to be restored by explicitly adding
  3973     meta-level quantifiers in the introduction rules, i.e.
  3974 
  3975       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3976 
  3977   - The format of the elimination rules is now
  3978 
  3979       p z_1 ... z_m x_1 ... x_n ==>
  3980         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3981         ==> ... ==> P
  3982 
  3983     for predicates and
  3984 
  3985       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3986         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3987         ==> ... ==> P
  3988 
  3989     for sets rather than
  3990 
  3991       x : s z_1 ... z_m ==>
  3992         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3993         ==> ... ==> P
  3994 
  3995     This may require terms in goals to be expanded to n-tuples
  3996     (e.g. using case_tac or simplification with the split_paired_all
  3997     rule) before the above elimination rule is applicable.
  3998 
  3999   - The elimination or case analysis rules for (mutually) inductive
  4000     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4001     list of rules "p_1_..._p_k.elims" is no longer available.
  4002 
  4003 * New package "function"/"fun" for general recursive functions,
  4004 supporting mutual and nested recursion, definitions in local contexts,
  4005 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4006 for small examples, and the separate tutorial on the function
  4007 package. The old recdef "package" is still available as before, but
  4008 users are encouraged to use the new package.
  4009 
  4010 * Method "lexicographic_order" automatically synthesizes termination
  4011 relations as lexicographic combinations of size measures. 
  4012 
  4013 * Case-expressions allow arbitrary constructor-patterns (including
  4014 "_") and take their order into account, like in functional
  4015 programming.  Internally, this is translated into nested
  4016 case-expressions; missing cases are added and mapped to the predefined
  4017 constant "undefined". In complicated cases printing may no longer show
  4018 the original input but the internal form. Lambda-abstractions allow
  4019 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4020 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4021 variable.
  4022 
  4023 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4024 is an abbreviation for "of_nat :: nat => int". The simplification
  4025 rules for "of_nat" have been changed to work like "int" did
  4026 previously.  Potential INCOMPATIBILITY:
  4027   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4028   - of_nat_diff and of_nat_mult are no longer default simp rules
  4029 
  4030 * Method "algebra" solves polynomial equations over (semi)rings using
  4031 Groebner bases. The (semi)ring structure is defined by locales and the
  4032 tool setup depends on that generic context. Installing the method for
  4033 a specific type involves instantiating the locale and possibly adding
  4034 declarations for computation on the coefficients.  The method is
  4035 already instantiated for natural numbers and for the axiomatic class
  4036 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4037 CALCULEMUS 2007 for the general principles underlying this
  4038 architecture of context-aware proof-tools.
  4039 
  4040 * Method "ferrack" implements quantifier elimination over
  4041 special-purpose dense linear orders using locales (analogous to
  4042 "algebra"). The method is already installed for class
  4043 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4044 rat, etc.
  4045 
  4046 * Former constant "List.op @" now named "List.append".  Use ML
  4047 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4048 circumvent possible incompatibilities when working on ML level.
  4049 
  4050 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4051 
  4052 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4053 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4054 
  4055 * New syntax for Haskell-like list comprehension (input only), eg.
  4056 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4057 
  4058 * The special syntax for function "filter" has changed from [x :
  4059 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4060 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4061 
  4062 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4063 defined on nat only, as an abbreviation for [a..<Suc b]
  4064 INCOMPATIBILITY.
  4065 
  4066 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4067 
  4068 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4069 
  4070 * New lemma collection field_simps (an extension of ring_simps) for
  4071 manipulating (in)equations involving division. Multiplies with all
  4072 denominators that can be proved to be non-zero (in equations) or
  4073 positive/negative (in inequations).
  4074 
  4075 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4076 have been improved and renamed to ring_simps, group_simps and
  4077 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4078 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4079 
  4080 * Theory Library/Commutative_Ring: switched from recdef to function
  4081 package; constants add, mul, pow now curried.  Infix syntax for
  4082 algebraic operations.
  4083 
  4084 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4085 INCOMPATIBILITY.
  4086 
  4087 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4088 INCOMPATIBILITY.
  4089 
  4090 * HOL/records: generalised field-update to take a function on the
  4091 field rather than the new value: r(|A := x|) is translated to A_update
  4092 (K x) r The K-combinator that is internally used is called K_record.
  4093 INCOMPATIBILITY: Usage of the plain update functions has to be
  4094 adapted.
  4095  
  4096 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4097 * x = 0, which are required for a semiring.  Richer structures do not
  4098 inherit from semiring_0 anymore, because this property is a theorem
  4099 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4100 there is more to prove, but this is mostly trivial.
  4101 
  4102 * Class "recpower" is generalized to arbitrary monoids, not just
  4103 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4104 commutativity or semiring properties additionally.
  4105 
  4106 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4107 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4108 better use 'abbreviation'.
  4109 
  4110 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4111 
  4112 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4113 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4114 significant changes for setting up numeral syntax for types:
  4115   - New constants Numeral.pred and Numeral.succ instead
  4116       of former Numeral.bin_pred and Numeral.bin_succ.
  4117   - Use integer operations instead of bin_add, bin_mult and so on.
  4118   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4119   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4120 
  4121 See src/HOL/Integ/IntArith.thy for an example setup.
  4122 
  4123 * Command 'normal_form' computes the normal form of a term that may
  4124 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4125 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4126 heavy-duty computations because the functions are compiled to ML
  4127 first.  Correspondingly, a method "normalization" is provided.  See
  4128 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4129 
  4130 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4131 25 like -->); output depends on the "iff" print_mode, the default is
  4132 "A = B" (with priority 50).
  4133 
  4134 * Relations less (<) and less_eq (<=) are also available on type bool.
  4135 Modified syntax to disallow nesting without explicit parentheses,
  4136 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4137 INCOMPATIBILITY.
  4138 
  4139 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4140 
  4141 * Relation composition operator "op O" now has precedence 75 and binds
  4142 stronger than union and intersection. INCOMPATIBILITY.
  4143 
  4144 * The old set interval syntax "{m..n(}" (and relatives) has been
  4145 removed.  Use "{m..<n}" (and relatives) instead.
  4146 
  4147 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4148 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4149 ``declare [[simproc del: neq]]''.
  4150 
  4151 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4152 True/False.
  4153 
  4154 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4155 
  4156 * Theorem setsum_mult renamed to setsum_right_distrib.
  4157 
  4158 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4159 ``rule'' method.
  4160 
  4161 * Reimplemented methods "sat" and "satx", with several improvements:
  4162 goals no longer need to be stated as "<prems> ==> False", equivalences
  4163 (i.e. "=" on type bool) are handled, variable names of the form
  4164 "lit_<n>" are no longer reserved, significant speedup.
  4165 
  4166 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4167 zChaff is still supported as well.
  4168 
  4169 * 'inductive' and 'datatype': provide projections of mutual rules,
  4170 bundled as foo_bar.inducts;
  4171 
  4172 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4173 Library.
  4174 
  4175 * Library: moved theory Accessible_Part to main HOL.
  4176 
  4177 * Library: added theory Coinductive_List of potentially infinite lists
  4178 as greatest fixed-point.
  4179 
  4180 * Library: added theory AssocList which implements (finite) maps as
  4181 association lists.
  4182 
  4183 * Method "evaluation" solves goals (i.e. a boolean expression)
  4184 efficiently by compiling it to ML.  The goal is "proved" (via an
  4185 oracle) if it evaluates to True.
  4186 
  4187 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4188 also when invoked by the simplifier.  This results in the Simplifier
  4189 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4190 Configuration option fast_arith_split_limit=0 recovers the old
  4191 behavior.
  4192 
  4193 * Support for hex (0x20) and binary (0b1001) numerals.
  4194 
  4195 * New method: reify eqs (t), where eqs are equations for an
  4196 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4197 parameter, computes a term s::'b and a list xs::'a list and proves the
  4198 theorem I xs s = t. This is also known as reification or quoting. The
  4199 resulting theorem is applied to the subgoal to substitute t with I xs
  4200 s.  If t is omitted, the subgoal itself is reified.
  4201 
  4202 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4203 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4204 where f is supposed to be a computable function (in the sense of code
  4205 generattion). The method uses reify to compute s and xs as above then
  4206 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4207 r and finally gets the theorem t = r, which is again applied to the
  4208 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4209 
  4210 * Reflection: Automatic reification now handels binding, an example is
  4211 available in src/HOL/ex/ReflectionEx.thy
  4212 
  4213 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4214 command 'statespace' that is similar to 'record', but introduces an
  4215 abstract specification based on the locale infrastructure instead of
  4216 HOL types.  This leads to extra flexibility in composing state spaces,
  4217 in particular multiple inheritance and renaming of components.
  4218 
  4219 
  4220 *** HOL-Complex ***
  4221 
  4222 * Hyperreal: Functions root and sqrt are now defined on negative real
  4223 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4224 Nonnegativity side conditions have been removed from many lemmas, so
  4225 that more subgoals may now be solved by simplification; potential
  4226 INCOMPATIBILITY.
  4227 
  4228 * Real: new type classes formalize real normed vector spaces and
  4229 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4230 and norm :: 'a => real.
  4231 
  4232 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4233 reals into other types. The overloaded constant Reals :: 'a set is now
  4234 defined as range of_real; potential INCOMPATIBILITY.
  4235 
  4236 * Real: proper support for ML code generation, including 'quickcheck'.
  4237 Reals are implemented as arbitrary precision rationals.
  4238 
  4239 * Hyperreal: Several constants that previously worked only for the
  4240 reals have been generalized, so they now work over arbitrary vector
  4241 spaces. Type annotations may need to be added in some cases; potential
  4242 INCOMPATIBILITY.
  4243 
  4244   Infinitesimal  :: ('a::real_normed_vector) star set
  4245   HFinite        :: ('a::real_normed_vector) star set
  4246   HInfinite      :: ('a::real_normed_vector) star set
  4247   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4248   monad          :: ('a::real_normed_vector) star => 'a star set
  4249   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4250   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4251   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4252   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4253   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4254   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4255   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4256   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4257   sgn            :: 'a::real_normed_vector => 'a
  4258   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4259 
  4260 * Complex: Some complex-specific constants are now abbreviations for
  4261 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4262 hnorm.  Other constants have been entirely removed in favor of the
  4263 polymorphic versions (INCOMPATIBILITY):
  4264 
  4265   approx        <-- capprox
  4266   HFinite       <-- CFinite
  4267   HInfinite     <-- CInfinite
  4268   Infinitesimal <-- CInfinitesimal
  4269   monad         <-- cmonad
  4270   galaxy        <-- cgalaxy
  4271   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4272   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4273   (ns)deriv     <-- (ns)cderiv
  4274 
  4275 
  4276 *** HOL-Algebra ***
  4277 
  4278 * Formalisation of ideals and the quotient construction over rings.
  4279 
  4280 * Order and lattice theory no longer based on records.
  4281 INCOMPATIBILITY.
  4282 
  4283 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4284 greatest_closed.  INCOMPATIBILITY.
  4285 
  4286 * Method algebra is now set up via an attribute.  For examples see
  4287 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4288 of algebraic structures.
  4289 
  4290 * Renamed theory CRing to Ring.
  4291 
  4292 
  4293 *** HOL-Nominal ***
  4294 
  4295 * Substantial, yet incomplete support for nominal datatypes (binding
  4296 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4297 src/HOL/Nominal/Examples.  Prospective users should consult
  4298 http://isabelle.in.tum.de/nominal/
  4299 
  4300 
  4301 *** ML ***
  4302 
  4303 * ML basics: just one true type int, which coincides with IntInf.int
  4304 (even on SML/NJ).
  4305 
  4306 * ML within Isar: antiquotations allow to embed statically-checked
  4307 formal entities in the source, referring to the context available at
  4308 compile-time.  For example:
  4309 
  4310 ML {* @{sort "{zero,one}"} *}
  4311 ML {* @{typ "'a => 'b"} *}
  4312 ML {* @{term "%x. x"} *}
  4313 ML {* @{prop "x == y"} *}
  4314 ML {* @{ctyp "'a => 'b"} *}
  4315 ML {* @{cterm "%x. x"} *}
  4316 ML {* @{cprop "x == y"} *}
  4317 ML {* @{thm asm_rl} *}
  4318 ML {* @{thms asm_rl} *}
  4319 ML {* @{type_name c} *}
  4320 ML {* @{type_syntax c} *}
  4321 ML {* @{const_name c} *}
  4322 ML {* @{const_syntax c} *}
  4323 ML {* @{context} *}
  4324 ML {* @{theory} *}
  4325 ML {* @{theory Pure} *}
  4326 ML {* @{theory_ref} *}
  4327 ML {* @{theory_ref Pure} *}
  4328 ML {* @{simpset} *}
  4329 ML {* @{claset} *}
  4330 ML {* @{clasimpset} *}
  4331 
  4332 The same works for sources being ``used'' within an Isar context.
  4333 
  4334 * ML in Isar: improved error reporting; extra verbosity with
  4335 ML_Context.trace enabled.
  4336 
  4337 * Pure/General/table.ML: the join operations now works via exceptions
  4338 DUP/SAME instead of type option. This is simpler in simple cases, and
  4339 admits slightly more efficient complex applications.
  4340 
  4341 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4342 use Context.generic instead of just theory.
  4343 
  4344 * Pure: datatype Context.generic joins theory/Proof.context and
  4345 provides some facilities for code that works in either kind of
  4346 context, notably GenericDataFun for uniform theory and proof data.
  4347 
  4348 * Pure: simplified internal attribute type, which is now always
  4349 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4350 local (Proof.context) attributes have been discontinued, while
  4351 minimizing code duplication. Thm.rule_attribute and
  4352 Thm.declaration_attribute build canonical attributes; see also structure
  4353 Context for further operations on Context.generic, notably
  4354 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4355 declarations and definitions.
  4356 
  4357 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4358 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4359 init only required for impure data. INCOMPATIBILITY: empty really need
  4360 to be empty (no dependencies on theory content!)
  4361 
  4362 * Pure/kernel: consts certification ignores sort constraints given in
  4363 signature declarations. (This information is not relevant to the
  4364 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4365 potential INCOMPATIBILITY.
  4366 
  4367 * Pure: axiomatic type classes are now purely definitional, with
  4368 explicit proofs of class axioms and super class relations performed
  4369 internally. See Pure/axclass.ML for the main internal interfaces --
  4370 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4371 AxClass.axiomatize_class/classrel/arity supersede
  4372 Sign.add_classes/classrel/arities.
  4373 
  4374 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4375 global/local versions on theory vs. Proof.context have been
  4376 discontinued; Attrib.syntax and Method.syntax have been adapted
  4377 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4378 attributes, methods, etc.
  4379 
  4380 * Pure: several functions of signature "... -> theory -> theory * ..."
  4381 have been reoriented to "... -> theory -> ... * theory" in order to
  4382 allow natural usage in combination with the ||>, ||>>, |-> and
  4383 fold_map combinators.
  4384 
  4385 * Pure: official theorem names (closed derivations) and additional
  4386 comments (tags) are now strictly separate.  Name hints -- which are
  4387 maintained as tags -- may be attached any time without affecting the
  4388 derivation.
  4389 
  4390 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4391 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4392 achieve the old behaviour.
  4393 
  4394 * Pure: the "Goal" constant is now called "prop", supporting a
  4395 slightly more general idea of ``protecting'' meta-level rule
  4396 statements.
  4397 
  4398 * Pure: Logic.(un)varify only works in a global context, which is now
  4399 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4400 Logic.legacy_(un)varify as temporary workaround.
  4401 
  4402 * Pure: structure Name provides scalable operations for generating
  4403 internal variable names, notably Name.variants etc.  This replaces
  4404 some popular functions from term.ML:
  4405 
  4406   Term.variant		->  Name.variant
  4407   Term.variantlist	->  Name.variant_list
  4408   Term.invent_names	->  Name.invent_list
  4409 
  4410 Note that low-level renaming rarely occurs in new code -- operations
  4411 from structure Variable are used instead (see below).
  4412 
  4413 * Pure: structure Variable provides fundamental operations for proper
  4414 treatment of fixed/schematic variables in a context.  For example,
  4415 Variable.import introduces fixes for schematics of given facts and
  4416 Variable.export reverses the effect (up to renaming) -- this replaces
  4417 various freeze_thaw operations.
  4418 
  4419 * Pure: structure Goal provides simple interfaces for
  4420 init/conclude/finish and tactical prove operations (replacing former
  4421 Tactic.prove).  Goal.prove is the canonical way to prove results
  4422 within a given context; Goal.prove_global is a degraded version for
  4423 theory level goals, including a global Drule.standard.  Note that
  4424 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4425 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4426 in a locale context).
  4427 
  4428 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4429 and type checking (Syntax.check_term etc.), with common combinations
  4430 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4431 which are considered legacy and await removal.
  4432 
  4433 * Pure/Syntax: generic interfaces for type unchecking
  4434 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4435 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4436 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4437 available for convenience, but refer to the very same operations using
  4438 a mere theory instead of a full context.
  4439 
  4440 * Isar: simplified treatment of user-level errors, using exception
  4441 ERROR of string uniformly.  Function error now merely raises ERROR,
  4442 without any side effect on output channels.  The Isar toplevel takes
  4443 care of proper display of ERROR exceptions.  ML code may use plain
  4444 handle/can/try; cat_error may be used to concatenate errors like this:
  4445 
  4446   ... handle ERROR msg => cat_error msg "..."
  4447 
  4448 Toplevel ML code (run directly or through the Isar toplevel) may be
  4449 embedded into the Isar toplevel with exception display/debug like
  4450 this:
  4451 
  4452   Isar.toplevel (fn () => ...)
  4453 
  4454 INCOMPATIBILITY, removed special transform_error facilities, removed
  4455 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4456 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4457 -- use plain ERROR instead.
  4458 
  4459 * Isar: theory setup now has type (theory -> theory), instead of a
  4460 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4461 
  4462 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4463 ProofContext.debug/verbose flags.
  4464 
  4465 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4466 theory before entering a proof state.  Transactions now always see a
  4467 quasi-functional intermediate checkpoint, both in interactive and
  4468 batch mode.
  4469 
  4470 * Isar: simplified interfaces for outer syntax.  Renamed
  4471 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4472 OuterSyntax.add_parsers -- this functionality is now included in
  4473 OuterSyntax.command etc.  INCOMPATIBILITY.
  4474 
  4475 * Simplifier: the simpset of a running simplification process now
  4476 contains a proof context (cf. Simplifier.the_context), which is the
  4477 very context that the initial simpset has been retrieved from (by
  4478 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4479 (solver, looper etc.) may depend on arbitrary proof data.
  4480 
  4481 * Simplifier.inherit_context inherits the proof context (plus the
  4482 local bounds) of the current simplification process; any simproc
  4483 etc. that calls the Simplifier recursively should do this!  Removed
  4484 former Simplifier.inherit_bounds, which is already included here --
  4485 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4486 specify an explicit context using Simplifier.context/theory_context.
  4487 
  4488 * Simplifier/Classical Reasoner: more abstract interfaces
  4489 change_simpset/claset for modifying the simpset/claset reference of a
  4490 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4491 INCOMPATIBILITY.
  4492 
  4493 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4494 "Trueprop" etc.
  4495 
  4496 
  4497 *** System ***
  4498 
  4499 * settings: the default heap location within ISABELLE_HOME_USER now
  4500 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4501 Isabelle installations.
  4502 
  4503 * isabelle-process: option -S (secure mode) disables some critical
  4504 operations, notably runtime compilation and evaluation of ML source
  4505 code.
  4506 
  4507 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4508 
  4509 * Support for parallel execution, using native multicore support of
  4510 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4511 independent theories, according to the given theory header
  4512 specifications. The maximum number of worker threads is specified via
  4513 usedir option -M or the "max-threads" setting in Proof General. A
  4514 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4515 to 6 on a 8-core machine.  User-code needs to observe certain
  4516 guidelines for thread-safe programming, see appendix A in the Isar
  4517 Implementation manual.
  4518 
  4519 
  4520 
  4521 New in Isabelle2005 (October 2005)
  4522 ----------------------------------
  4523 
  4524 *** General ***
  4525 
  4526 * Theory headers: the new header syntax for Isar theories is
  4527 
  4528   theory <name>
  4529   imports <theory1> ... <theoryN>
  4530   uses <file1> ... <fileM>
  4531   begin
  4532 
  4533 where the 'uses' part is optional.  The previous syntax
  4534 
  4535   theory <name> = <theory1> + ... + <theoryN>:
  4536 
  4537 will disappear in the next release.  Use isatool fixheaders to convert
  4538 existing theory files.  Note that there is no change in ancient
  4539 non-Isar theories now, but these will disappear soon.
  4540 
  4541 * Theory loader: parent theories can now also be referred to via
  4542 relative and absolute paths.
  4543 
  4544 * Command 'find_theorems' searches for a list of criteria instead of a
  4545 list of constants. Known criteria are: intro, elim, dest, name:string,
  4546 simp:term, and any term. Criteria can be preceded by '-' to select
  4547 theorems that do not match. Intro, elim, dest select theorems that
  4548 match the current goal, name:s selects theorems whose fully qualified
  4549 name contain s, and simp:term selects all simplification rules whose
  4550 lhs match term.  Any other term is interpreted as pattern and selects
  4551 all theorems matching the pattern. Available in ProofGeneral under
  4552 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4553 
  4554   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4555 
  4556 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4557 matching the current goal as introduction rule and not having "HOL."
  4558 in their name (i.e. not being defined in theory HOL).
  4559 
  4560 * Command 'thms_containing' has been discontinued in favour of
  4561 'find_theorems'; INCOMPATIBILITY.
  4562 
  4563 * Communication with Proof General is now 8bit clean, which means that
  4564 Unicode text in UTF-8 encoding may be used within theory texts (both
  4565 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4566 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4567 
  4568   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4569   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4570 
  4571 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4572 Classical Reasoner.  Typical big applications run around 2 times
  4573 faster.
  4574 
  4575 
  4576 *** Document preparation ***
  4577 
  4578 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4579 of raw sources.  Only those symbols that do not require additional
  4580 LaTeX packages (depending on comments in isabellesym.sty) are
  4581 displayed properly, everything else is left verbatim.  isatool display
  4582 and isatool print are used as front ends (these are subject to the
  4583 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4584 
  4585 * Command tags control specific markup of certain regions of text,
  4586 notably folding and hiding.  Predefined tags include "theory" (for
  4587 theory begin and end), "proof" for proof commands, and "ML" for
  4588 commands involving ML code; the additional tags "visible" and
  4589 "invisible" are unused by default.  Users may give explicit tag
  4590 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4591 interpretation of tags is determined by the LaTeX job during document
  4592 preparation: see option -V of isatool usedir, or options -n and -t of
  4593 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4594 \isadroptag.
  4595 
  4596 Several document versions may be produced at the same time via isatool
  4597 usedir (the generated index.html will link all of them).  Typical
  4598 specifications include ''-V document=theory,proof,ML'' to present
  4599 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4600 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4601 these parts without any formal replacement text.  The Isabelle site
  4602 default settings produce ''document'' and ''outline'' versions as
  4603 specified above.
  4604 
  4605 * Several new antiquotations:
  4606 
  4607   @{term_type term} prints a term with its type annotated;
  4608 
  4609   @{typeof term} prints the type of a term;
  4610 
  4611   @{const const} is the same as @{term const}, but checks that the
  4612   argument is a known logical constant;
  4613 
  4614   @{term_style style term} and @{thm_style style thm} print a term or
  4615   theorem applying a "style" to it
  4616 
  4617   @{ML text}
  4618 
  4619 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4620 definitions, equations, inequations etc., 'concl' printing only the
  4621 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4622 to print the specified premise.  TermStyle.add_style provides an ML
  4623 interface for introducing further styles.  See also the "LaTeX Sugar"
  4624 document practical applications.  The ML antiquotation prints
  4625 type-checked ML expressions verbatim.
  4626 
  4627 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4628 and 'text' support optional locale specification '(in loc)', which
  4629 specifies the default context for interpreting antiquotations.  For
  4630 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4631 
  4632 * Option 'locale=NAME' of antiquotations specifies an alternative
  4633 context interpreting the subsequent argument.  For example: @{thm
  4634 [locale=lattice] inf_assoc}.
  4635 
  4636 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4637 a proof context.
  4638 
  4639 * Proper output of antiquotations for theory commands involving a
  4640 proof context (such as 'locale' or 'theorem (in loc) ...').
  4641 
  4642 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4643 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4644 
  4645 * isatool usedir: new option -C (default true) controls whether option
  4646 -D should include a copy of the original document directory; -C false
  4647 prevents unwanted effects such as copying of administrative CVS data.
  4648 
  4649 
  4650 *** Pure ***
  4651 
  4652 * Considerably improved version of 'constdefs' command.  Now performs
  4653 automatic type-inference of declared constants; additional support for
  4654 local structure declarations (cf. locales and HOL records), see also
  4655 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4656 sequential dependencies of definitions within a single 'constdefs'
  4657 section; moreover, the declared name needs to be an identifier.  If
  4658 all fails, consider to fall back on 'consts' and 'defs' separately.
  4659 
  4660 * Improved indexed syntax and implicit structures.  First of all,
  4661 indexed syntax provides a notational device for subscripted
  4662 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4663 expressions.  Secondly, in a local context with structure
  4664 declarations, number indexes \<^sub>n or the empty index (default
  4665 number 1) refer to a certain fixed variable implicitly; option
  4666 show_structs controls printing of implicit structures.  Typical
  4667 applications of these concepts involve record types and locales.
  4668 
  4669 * New command 'no_syntax' removes grammar declarations (and
  4670 translations) resulting from the given syntax specification, which is
  4671 interpreted in the same manner as for the 'syntax' command.
  4672 
  4673 * 'Advanced' translation functions (parse_translation etc.) may depend
  4674 on the signature of the theory context being presently used for
  4675 parsing/printing, see also isar-ref manual.
  4676 
  4677 * Improved 'oracle' command provides a type-safe interface to turn an
  4678 ML expression of type theory -> T -> term into a primitive rule of
  4679 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4680 is already included here); see also FOL/ex/IffExample.thy;
  4681 INCOMPATIBILITY.
  4682 
  4683 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4684 before); "cI" is no longer bound, use "c.intro" instead.
  4685 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4686 axclasses vs. locales.
  4687 
  4688 * Improved internal renaming of symbolic identifiers -- attach primes
  4689 instead of base 26 numbers.
  4690 
  4691 * New flag show_question_marks controls printing of leading question
  4692 marks in schematic variable names.
  4693 
  4694 * In schematic variable names, *any* symbol following \<^isub> or
  4695 \<^isup> is now treated as part of the base name.  For example, the
  4696 following works without printing of awkward ".0" indexes:
  4697 
  4698   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4699     by simp
  4700 
  4701 * Inner syntax includes (*(*nested*) comments*).
  4702 
  4703 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4704 annotations as "(00...)".
  4705 
  4706 * Clear separation of logical types and nonterminals, where the latter
  4707 may only occur in 'syntax' specifications or type abbreviations.
  4708 Before that distinction was only partially implemented via type class
  4709 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4710 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4711 exotic syntax specifications may require further adaption
  4712 (e.g. Cube/Cube.thy).
  4713 
  4714 * Removed obsolete type class "logic", use the top sort {} instead.
  4715 Note that non-logical types should be declared as 'nonterminals'
  4716 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4717 specifications.
  4718 
  4719 * Attributes 'induct' and 'cases': type or set names may now be
  4720 locally fixed variables as well.
  4721 
  4722 * Simplifier: can now control the depth to which conditional rewriting
  4723 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4724 Limit.
  4725 
  4726 * Simplifier: simplification procedures may now take the current
  4727 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4728 interface), which is very useful for calling the Simplifier
  4729 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4730 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4731 low-level mk_simproc no longer applies Logic.varify internally, to
  4732 allow for use in a context of fixed variables.
  4733 
  4734 * thin_tac now works even if the assumption being deleted contains !!
  4735 or ==>.  More generally, erule now works even if the major premise of
  4736 the elimination rule contains !! or ==>.
  4737 
  4738 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4739 
  4740 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4741 from Pure, which contains all common declarations already.  Both
  4742 theories are defined via plain Isabelle/Isar .thy files.
  4743 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4744 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4745 use isatool fixcpure to adapt your theory and ML sources.
  4746 
  4747 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4748 selections of theorems in named facts via index ranges.
  4749 
  4750 * 'print_theorems': in theory mode, really print the difference
  4751 wrt. the last state (works for interactive theory development only),
  4752 in proof mode print all local facts (cf. 'print_facts');
  4753 
  4754 * 'hide': option '(open)' hides only base names.
  4755 
  4756 * More efficient treatment of intermediate checkpoints in interactive
  4757 theory development.
  4758 
  4759 * Code generator is now invoked via code_module (incremental code
  4760 generation) and code_library (modular code generation, ML structures
  4761 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4762 must be quoted when used as identifiers.
  4763 
  4764 * New 'value' command for reading, evaluating and printing terms using
  4765 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4766 quoted when used as identifier.
  4767 
  4768 
  4769 *** Locales ***
  4770 
  4771 * New commands for the interpretation of locale expressions in
  4772 theories (1), locales (2) and proof contexts (3).  These generate
  4773 proof obligations from the expression specification.  After the
  4774 obligations have been discharged, theorems of the expression are added
  4775 to the theory, target locale or proof context.  The synopsis of the
  4776 commands is a follows:
  4777 
  4778   (1) interpretation expr inst
  4779   (2) interpretation target < expr
  4780   (3) interpret expr inst
  4781 
  4782 Interpretation in theories and proof contexts require a parameter
  4783 instantiation of terms from the current context.  This is applied to
  4784 specifications and theorems of the interpreted expression.
  4785 Interpretation in locales only permits parameter renaming through the
  4786 locale expression.  Interpretation is smart in that interpretations
  4787 that are active already do not occur in proof obligations, neither are
  4788 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4789 inspect active interpretations of a particular locale.  For details,
  4790 see the Isar Reference manual.  Examples can be found in
  4791 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4792 
  4793 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4794 'interpret' instead.
  4795 
  4796 * New context element 'constrains' for adding type constraints to
  4797 parameters.
  4798 
  4799 * Context expressions: renaming of parameters with syntax
  4800 redeclaration.
  4801 
  4802 * Locale declaration: 'includes' disallowed.
  4803 
  4804 * Proper static binding of attribute syntax -- i.e. types / terms /
  4805 facts mentioned as arguments are always those of the locale definition
  4806 context, independently of the context of later invocations.  Moreover,
  4807 locale operations (renaming and type / term instantiation) are applied
  4808 to attribute arguments as expected.
  4809 
  4810 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4811 actual attributes; rare situations may require Attrib.attribute to
  4812 embed those attributes into Attrib.src that lack concrete syntax.
  4813 Attribute implementations need to cooperate properly with the static
  4814 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4815 Attrib.XXX_thm etc. already do the right thing without further
  4816 intervention.  Only unusual applications -- such as "where" or "of"
  4817 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4818 on the context and the facts involved -- may have to assign parsed
  4819 values to argument tokens explicitly.
  4820 
  4821 * Changed parameter management in theorem generation for long goal
  4822 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4823 theorem statement in rare situations.
  4824 
  4825 * Locale inspection command 'print_locale' omits notes elements.  Use
  4826 'print_locale!' to have them included in the output.
  4827 
  4828 
  4829 *** Provers ***
  4830 
  4831 * Provers/hypsubst.ML: improved version of the subst method, for
  4832 single-step rewriting: it now works in bound variable contexts. New is
  4833 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4834 rewrite a different subterm than the original subst method, which is
  4835 still available as 'simplesubst'.
  4836 
  4837 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4838 and quasi orders.
  4839 
  4840 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4841 reflexive-transitive closure of relations.
  4842 
  4843 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4844 limit (previously hard-coded with a value of 20) user-definable.
  4845 
  4846 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4847 is peformed already.  Object-logics merely need to finish their
  4848 initial simpset configuration as before.  INCOMPATIBILITY.
  4849 
  4850 
  4851 *** HOL ***
  4852 
  4853 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4854 
  4855   syntax (epsilon)
  4856     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4857 
  4858 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4859 and x-symbol; use option '-m epsilon' to get it actually printed.
  4860 Moreover, the mathematically important symbolic identifier \<epsilon>
  4861 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4862 
  4863 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4864 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4865 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4866 support corresponding Isar calculations.
  4867 
  4868 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4869 instead of ":".
  4870 
  4871 * theory SetInterval: changed the syntax for open intervals:
  4872 
  4873   Old       New
  4874   {..n(}    {..<n}
  4875   {)n..}    {n<..}
  4876   {m..n(}   {m..<n}
  4877   {)m..n}   {m<..n}
  4878   {)m..n(}  {m<..<n}
  4879 
  4880 The old syntax is still supported but will disappear in the next
  4881 release.  For conversion use the following Emacs search and replace
  4882 patterns (these are not perfect but work quite well):
  4883 
  4884   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4885   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4886 
  4887 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4888 equalities in commutative rings; method 'algebra' provides a generic
  4889 interface.
  4890 
  4891 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4892 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4893 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4894 be a tuple pattern.
  4895 
  4896 Some new syntax forms are available:
  4897 
  4898   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4899   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4900   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4901   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4902 
  4903 The latter form "\<Sum>x < k. e" used to be based on a separate
  4904 function "Summation", which has been discontinued.
  4905 
  4906 * theory Finite_Set: in structured induction proofs, the insert case
  4907 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4908 (insert F x)'.
  4909 
  4910 * The 'refute' command has been extended to support a much larger
  4911 fragment of HOL, including axiomatic type classes, constdefs and
  4912 typedefs, inductive datatypes and recursion.
  4913 
  4914 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4915 Requires zChaff with proof generation to be installed.  See
  4916 HOL/ex/SAT_Examples.thy for examples.
  4917 
  4918 * Datatype induction via method 'induct' now preserves the name of the
  4919 induction variable. For example, when proving P(xs::'a list) by
  4920 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4921 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4922 in unstructured proof scripts.
  4923 
  4924 * Reworked implementation of records.  Improved scalability for
  4925 records with many fields, avoiding performance problems for type
  4926 inference. Records are no longer composed of nested field types, but
  4927 of nested extension types. Therefore the record type only grows linear
  4928 in the number of extensions and not in the number of fields.  The
  4929 top-level (users) view on records is preserved.  Potential
  4930 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4931 old record representation. The type generated for a record is called
  4932 <record_name>_ext_type.
  4933 
  4934 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4935 proofs triggered by a record definition or a simproc (if
  4936 quick_and_dirty is enabled).  Definitions of large records can take
  4937 quite long.
  4938 
  4939 New simproc record_upd_simproc for simplification of multiple record
  4940 updates enabled by default.  Moreover, trivial updates are also
  4941 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4942 occasionally, since simplification is more powerful by default.
  4943 
  4944 * typedef: proper support for polymorphic sets, which contain extra
  4945 type-variables in the term.
  4946 
  4947 * Simplifier: automatically reasons about transitivity chains
  4948 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4949 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4950 old proofs break occasionally as simplification may now solve more
  4951 goals than previously.
  4952 
  4953 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4954 present.  Works for all partial orders (class "order"), in particular
  4955 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4956 just like y <= x.
  4957 
  4958 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4959 bound variable or a constant then the let is unfolded.  Otherwise
  4960 first a is simplified to b, and then f b is simplified to g. If
  4961 possible we abstract b from g arriving at "let x = b in h x",
  4962 otherwise we unfold the let and arrive at g.  The simproc can be
  4963 enabled/disabled by the reference use_let_simproc.  Potential
  4964 INCOMPATIBILITY since simplification is more powerful by default.
  4965 
  4966 * Classical reasoning: the meson method now accepts theorems as arguments.
  4967 
  4968 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4969 jobs to provide advice on the provability of subgoals.
  4970 
  4971 * Theory OrderedGroup and Ring_and_Field: various additions and
  4972 improvements to faciliate calculations involving equalities and
  4973 inequalities.
  4974 
  4975 The following theorems have been eliminated or modified
  4976 (INCOMPATIBILITY):
  4977 
  4978   abs_eq             now named abs_of_nonneg
  4979   abs_of_ge_0        now named abs_of_nonneg
  4980   abs_minus_eq       now named abs_of_nonpos
  4981   imp_abs_id         now named abs_of_nonneg
  4982   imp_abs_neg_id     now named abs_of_nonpos
  4983   mult_pos           now named mult_pos_pos
  4984   mult_pos_le        now named mult_nonneg_nonneg
  4985   mult_pos_neg_le    now named mult_nonneg_nonpos
  4986   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4987   mult_neg           now named mult_neg_neg
  4988   mult_neg_le        now named mult_nonpos_nonpos
  4989 
  4990 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4991      
  4992      zero_le_square
  4993      not_square_less_zero 
  4994 
  4995   The following lemmas have been deleted from Real/RealPow:
  4996   
  4997      realpow_zero_zero
  4998      realpow_two
  4999      realpow_less
  5000      zero_le_power
  5001      realpow_two_le
  5002      abs_realpow_two
  5003      realpow_two_abs     
  5004 
  5005 * Theory Parity: added rules for simplifying exponents.
  5006 
  5007 * Theory List:
  5008 
  5009 The following theorems have been eliminated or modified
  5010 (INCOMPATIBILITY):
  5011 
  5012   list_all_Nil       now named list_all.simps(1)
  5013   list_all_Cons      now named list_all.simps(2)
  5014   list_all_conv      now named list_all_iff
  5015   set_mem_eq         now named mem_iff
  5016 
  5017 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5018 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5019 
  5020 
  5021 *** HOL-Complex ***
  5022 
  5023 * Theory RealDef: better support for embedding natural numbers and
  5024 integers in the reals.
  5025 
  5026 The following theorems have been eliminated or modified
  5027 (INCOMPATIBILITY):
  5028 
  5029   exp_ge_add_one_self  now requires no hypotheses
  5030   real_of_int_add      reversed direction of equality (use [symmetric])
  5031   real_of_int_minus    reversed direction of equality (use [symmetric])
  5032   real_of_int_diff     reversed direction of equality (use [symmetric])
  5033   real_of_int_mult     reversed direction of equality (use [symmetric])
  5034 
  5035 * Theory RComplete: expanded support for floor and ceiling functions.
  5036 
  5037 * Theory Ln is new, with properties of the natural logarithm
  5038 
  5039 * Hyperreal: There is a new type constructor "star" for making
  5040 nonstandard types.  The old type names are now type synonyms:
  5041 
  5042   hypreal = real star
  5043   hypnat = nat star
  5044   hcomplex = complex star
  5045 
  5046 * Hyperreal: Many groups of similarly-defined constants have been
  5047 replaced by polymorphic versions (INCOMPATIBILITY):
  5048 
  5049   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5050 
  5051   starset      <-- starsetNat, starsetC
  5052   *s*          <-- *sNat*, *sc*
  5053   starset_n    <-- starsetNat_n, starsetC_n
  5054   *sn*         <-- *sNatn*, *scn*
  5055   InternalSets <-- InternalNatSets, InternalCSets
  5056 
  5057   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5058   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5059   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5060   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5061   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5062 
  5063 * Hyperreal: Many type-specific theorems have been removed in favor of
  5064 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5065 
  5066   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5067   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5068   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5069   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5070   right_minus <-- hypreal_add_minus
  5071   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5072   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5073   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5074   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5075   mult_1_right <-- hcomplex_mult_one_right
  5076   mult_zero_left <-- hcomplex_mult_zero_left
  5077   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5078   right_distrib <-- hypnat_add_mult_distrib2
  5079   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5080   right_inverse <-- hypreal_mult_inverse
  5081   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5082   order_refl <-- {hypreal,hypnat}_le_refl
  5083   order_trans <-- {hypreal,hypnat}_le_trans
  5084   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5085   order_less_le <-- {hypreal,hypnat}_less_le
  5086   linorder_linear <-- {hypreal,hypnat}_le_linear
  5087   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5088   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5089   add_nonneg_nonneg <-- hypreal_le_add_order
  5090 
  5091 * Hyperreal: Separate theorems having to do with type-specific
  5092 versions of constants have been merged into theorems that apply to the
  5093 new polymorphic constants (INCOMPATIBILITY):
  5094 
  5095   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5096   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5097   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5098   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5099   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5100   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5101   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5102   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5103   STAR_diff <-- {STAR,STARC}_diff
  5104   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5105     STARC_hcomplex_of_complex}_image_subset
  5106   starset_n_Un <-- starset{Nat,C}_n_Un
  5107   starset_n_Int <-- starset{Nat,C}_n_Int
  5108   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5109   starset_n_diff <-- starset{Nat,C}_n_diff
  5110   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5111   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5112   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5113   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5114   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5115   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5116   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5117   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5118   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5119   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5120   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5121   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5122   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5123   starfun_diff <-- starfun{C,RC,CR}_diff
  5124   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5125   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5126   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5127   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5128   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5129   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5130   starfun_Id <-- starfunC_Id
  5131   starfun_approx <-- starfun{Nat,CR}_approx
  5132   starfun_capprox <-- starfun{C,RC}_capprox
  5133   starfun_abs <-- starfunNat_rabs
  5134   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5135   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5136   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5137   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5138   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5139   starfun_add_approx <-- starfunCR_add_approx
  5140   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5141   starfun_divide <-- starfun{C,CR,RC}_divide
  5142   starfun_n <-- starfun{Nat,C}_n
  5143   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5144   starfun_n_add <-- starfun{Nat,C}_n_add
  5145   starfun_n_add_minus <-- starfunNat_n_add_minus
  5146   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5147   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5148   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5149 
  5150   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5151   star_n_minus <-- {hypreal,hcomplex}_minus
  5152   star_n_diff <-- {hypreal,hcomplex}_diff
  5153   star_n_mult <-- {hypreal,hcomplex}_mult
  5154   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5155   star_n_le <-- {hypreal,hypnat}_le
  5156   star_n_less <-- {hypreal,hypnat}_less
  5157   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5158   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5159   star_n_abs <-- hypreal_hrabs
  5160   star_n_divide <-- hcomplex_divide
  5161 
  5162   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5163   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5164   star_of_diff <-- hypreal_of_real_diff
  5165   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5166   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5167   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5168   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5169   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5170   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5171   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5172   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5173   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5174   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5175   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5176   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5177   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5178   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5179   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5180   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5181   star_of_power <-- hypreal_of_real_power
  5182   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5183 
  5184 * Hyperreal: new method "transfer" that implements the transfer
  5185 principle of nonstandard analysis. With a subgoal that mentions
  5186 nonstandard types like "'a star", the command "apply transfer"
  5187 replaces it with an equivalent one that mentions only standard types.
  5188 To be successful, all free variables must have standard types; non-
  5189 standard variables must have explicit universal quantifiers.
  5190 
  5191 * Hyperreal: A theory of Taylor series.
  5192 
  5193 
  5194 *** HOLCF ***
  5195 
  5196 * Discontinued special version of 'constdefs' (which used to support
  5197 continuous functions) in favor of the general Pure one with full
  5198 type-inference.
  5199 
  5200 * New simplification procedure for solving continuity conditions; it
  5201 is much faster on terms with many nested lambda abstractions (cubic
  5202 instead of exponential time).
  5203 
  5204 * New syntax for domain package: selector names are now optional.
  5205 Parentheses should be omitted unless argument is lazy, for example:
  5206 
  5207   domain 'a stream = cons "'a" (lazy "'a stream")
  5208 
  5209 * New command 'fixrec' for defining recursive functions with pattern
  5210 matching; defining multiple functions with mutual recursion is also
  5211 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5212 sinr, or any data constructor defined by the domain package. The given
  5213 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5214 syntax and examples.
  5215 
  5216 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5217 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5218 but the proof obligation additionally includes an admissibility
  5219 requirement. The packages generate instances of class cpo or pcpo,
  5220 with continuity and strictness theorems for Rep and Abs.
  5221 
  5222 * HOLCF: Many theorems have been renamed according to a more standard naming
  5223 scheme (INCOMPATIBILITY):
  5224 
  5225   foo_inject:  "foo$x = foo$y ==> x = y"
  5226   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5227   foo_less:    "(foo$x << foo$y) = (x << y)"
  5228   foo_strict:  "foo$UU = UU"
  5229   foo_defined: "... ==> foo$x ~= UU"
  5230   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5231 
  5232 
  5233 *** ZF ***
  5234 
  5235 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5236 including the First Isomorphism Theorem (on quotienting by the kernel
  5237 of a homomorphism).
  5238 
  5239 * ZF/Simplifier: install second copy of type solver that actually
  5240 makes use of TC rules declared to Isar proof contexts (or locales);
  5241 the old version is still required for ML proof scripts.
  5242 
  5243 
  5244 *** Cube ***
  5245 
  5246 * Converted to Isar theory format; use locales instead of axiomatic
  5247 theories.
  5248 
  5249 
  5250 *** ML ***
  5251 
  5252 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5253 for ||>, ||>>, |>>,
  5254 
  5255 * Pure/library.ML no longer defines its own option datatype, but uses
  5256 that of the SML basis, which has constructors NONE and SOME instead of
  5257 None and Some, as well as exception Option.Option instead of OPTION.
  5258 The functions the, if_none, is_some, is_none have been adapted
  5259 accordingly, while Option.map replaces apsome.
  5260 
  5261 * Pure/library.ML: the exception LIST has been given up in favour of
  5262 the standard exceptions Empty and Subscript, as well as
  5263 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5264 superceded by the standard hd and tl functions etc.
  5265 
  5266 A number of basic list functions are no longer exported to the ML
  5267 toplevel, as they are variants of predefined functions.  The following
  5268 suggests how one can translate existing code:
  5269 
  5270     rev_append xs ys = List.revAppend (xs, ys)
  5271     nth_elem (i, xs) = List.nth (xs, i)
  5272     last_elem xs = List.last xs
  5273     flat xss = List.concat xss
  5274     seq fs = List.app fs
  5275     partition P xs = List.partition P xs
  5276     mapfilter f xs = List.mapPartial f xs
  5277 
  5278 * Pure/library.ML: several combinators for linear functional
  5279 transformations, notably reverse application and composition:
  5280 
  5281   x |> f                f #> g
  5282   (x, y) |-> f          f #-> g
  5283 
  5284 * Pure/library.ML: introduced/changed precedence of infix operators:
  5285 
  5286   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5287   infix 2 ?;
  5288   infix 3 o oo ooo oooo;
  5289   infix 4 ~~ upto downto;
  5290 
  5291 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5292 infix operators.
  5293 
  5294 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5295 fold_map support linear functional transformations and nesting.  For
  5296 example:
  5297 
  5298   fold f [x1, ..., xN] y =
  5299     y |> f x1 |> ... |> f xN
  5300 
  5301   (fold o fold) f [xs1, ..., xsN] y =
  5302     y |> fold f xs1 |> ... |> fold f xsN
  5303 
  5304   fold f [x1, ..., xN] =
  5305     f x1 #> ... #> f xN
  5306 
  5307   (fold o fold) f [xs1, ..., xsN] =
  5308     fold f xs1 #> ... #> fold f xsN
  5309 
  5310 * Pure/library.ML: the following selectors on type 'a option are
  5311 available:
  5312 
  5313   the:               'a option -> 'a  (*partial*)
  5314   these:             'a option -> 'a  where 'a = 'b list
  5315   the_default: 'a -> 'a option -> 'a
  5316   the_list:          'a option -> 'a list
  5317 
  5318 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5319 basic operations for association lists, following natural argument
  5320 order; moreover the explicit equality predicate passed here avoids
  5321 potentially expensive polymorphic runtime equality checks.
  5322 The old functions may be expressed as follows:
  5323 
  5324   assoc = uncurry (AList.lookup (op =))
  5325   assocs = these oo AList.lookup (op =)
  5326   overwrite = uncurry (AList.update (op =)) o swap
  5327 
  5328 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5329 
  5330   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5331   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5332 
  5333 replacing make_keylist and keyfilter (occassionally used)
  5334 Naive rewrites:
  5335 
  5336   make_keylist = AList.make
  5337   keyfilter = AList.find (op =)
  5338 
  5339 * eq_fst and eq_snd now take explicit equality parameter, thus
  5340   avoiding eqtypes. Naive rewrites:
  5341 
  5342     eq_fst = eq_fst (op =)
  5343     eq_snd = eq_snd (op =)
  5344 
  5345 * Removed deprecated apl and apr (rarely used).
  5346   Naive rewrites:
  5347 
  5348     apl (n, op) =>>= curry op n
  5349     apr (op, m) =>>= fn n => op (n, m)
  5350 
  5351 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5352 provides a reasonably efficient light-weight implementation of sets as
  5353 lists.
  5354 
  5355 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5356 few new operations; existing lookup and update are now curried to
  5357 follow natural argument order (for use with fold etc.);
  5358 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5359 
  5360 * Pure/General: output via the Isabelle channels of
  5361 writeln/warning/error etc. is now passed through Output.output, with a
  5362 hook for arbitrary transformations depending on the print_mode
  5363 (cf. Output.add_mode -- the first active mode that provides a output
  5364 function wins).  Already formatted output may be embedded into further
  5365 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5366 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5367 accommodate easy composition of diagnostic messages etc.  Programmers
  5368 rarely need to care about Output.output or Output.raw at all, with
  5369 some notable exceptions: Output.output is required when bypassing the
  5370 standard channels (writeln etc.), or in token translations to produce
  5371 properly formatted results; Output.raw is required when capturing
  5372 already output material that will eventually be presented to the user
  5373 a second time.  For the default print mode, both Output.output and
  5374 Output.raw have no effect.
  5375 
  5376 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5377 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5378 cumulative results are displayed at the end of a batch session.
  5379 
  5380 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5381 replaced by File.platform_path and File.shell_path (with appropriate
  5382 hooks).  This provides a clean interface for unusual systems where the
  5383 internal and external process view of file names are different.
  5384 
  5385 * Pure: more efficient orders for basic syntactic entities: added
  5386 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5387 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5388 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5389 orders now -- potential INCOMPATIBILITY for code that depends on a
  5390 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5391 Library.sort_strings on result).
  5392 
  5393 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5394 fold_types traverse types/terms from left to right, observing natural
  5395 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5396 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5397 
  5398 * Pure: name spaces have been refined, with significant changes of the
  5399 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5400 to extern(_table).  The plain name entry path is superceded by a
  5401 general 'naming' context, which also includes the 'policy' to produce
  5402 a fully qualified name and external accesses of a fully qualified
  5403 name; NameSpace.extend is superceded by context dependent
  5404 Sign.declare_name.  Several theory and proof context operations modify
  5405 the naming context.  Especially note Theory.restore_naming and
  5406 ProofContext.restore_naming to get back to a sane state; note that
  5407 Theory.add_path is no longer sufficient to recover from
  5408 Theory.absolute_path in particular.
  5409 
  5410 * Pure: new flags short_names (default false) and unique_names
  5411 (default true) for controlling output of qualified names.  If
  5412 short_names is set, names are printed unqualified.  If unique_names is
  5413 reset, the name prefix is reduced to the minimum required to achieve
  5414 the original result when interning again, even if there is an overlap
  5415 with earlier declarations.
  5416 
  5417 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5418 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5419 (useful for printing error messages).  INCOMPATIBILITY.
  5420 
  5421 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5422 Theory.theory are now identified, referring to the universal
  5423 Context.theory (see Pure/context.ML).  Actual signature and theory
  5424 content is managed as theory data.  The old code and interfaces were
  5425 spread over many files and structures; the new arrangement introduces
  5426 considerable INCOMPATIBILITY to gain more clarity:
  5427 
  5428   Context -- theory management operations (name, identity, inclusion,
  5429     parents, ancestors, merge, etc.), plus generic theory data;
  5430 
  5431   Sign -- logical signature and syntax operations (declaring consts,
  5432     types, etc.), plus certify/read for common entities;
  5433 
  5434   Theory -- logical theory operations (stating axioms, definitions,
  5435     oracles), plus a copy of logical signature operations (consts,
  5436     types, etc.); also a few basic management operations (Theory.copy,
  5437     Theory.merge, etc.)
  5438 
  5439 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5440 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5441 for convenience -- they merely return the theory.
  5442 
  5443 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5444 
  5445 * Pure: the Isar proof context type is already defined early in Pure
  5446 as Context.proof (note that ProofContext.context and Proof.context are
  5447 aliases, where the latter is the preferred name).  This enables other
  5448 Isabelle components to refer to that type even before Isar is present.
  5449 
  5450 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5451 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5452 any of these kinds.  For example, Sign.intern typeK is now
  5453 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5454 Theory.hide_types.  Also note that former
  5455 Theory.hide_classes/types/consts are now
  5456 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5457 internalize their arguments!  INCOMPATIBILITY.
  5458 
  5459 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5460 datatype thmref (with constructors Name and NameSelection) instead of
  5461 plain string -- INCOMPATIBILITY;
  5462 
  5463 * Pure: cases produced by proof methods specify options, where NONE
  5464 means to remove case bindings -- INCOMPATIBILITY in
  5465 (RAW_)METHOD_CASES.
  5466 
  5467 * Pure: the following operations retrieve axioms or theorems from a
  5468 theory node or theory hierarchy, respectively:
  5469 
  5470   Theory.axioms_of: theory -> (string * term) list
  5471   Theory.all_axioms_of: theory -> (string * term) list
  5472   PureThy.thms_of: theory -> (string * thm) list
  5473   PureThy.all_thms_of: theory -> (string * thm) list
  5474 
  5475 * Pure: print_tac now outputs the goal through the trace channel.
  5476 
  5477 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5478 Reference Toplevel.debug (default false) controls detailed printing
  5479 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5480 controls execution profiling -- set to 1 for time and 2 for space
  5481 (both increase the runtime).
  5482 
  5483 * Isar session: The initial use of ROOT.ML is now always timed,
  5484 i.e. the log will show the actual process times, in contrast to the
  5485 elapsed wall-clock time that the outer shell wrapper produces.
  5486 
  5487 * Simplifier: improved handling of bound variables (nameless
  5488 representation, avoid allocating new strings).  Simprocs that invoke
  5489 the Simplifier recursively should use Simplifier.inherit_bounds to
  5490 avoid local name clashes.  Failure to do so produces warnings
  5491 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5492 for further details.
  5493 
  5494 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5495 bindings for all theorems stored within a given theory; this may help
  5496 in porting non-Isar theories to Isar ones, while keeping ML proof
  5497 scripts for the time being.
  5498 
  5499 * ML operator HTML.with_charset specifies the charset begin used for
  5500 generated HTML files.  For example:
  5501 
  5502   HTML.with_charset "utf-8" use_thy "Hebrew";
  5503   HTML.with_charset "utf-8" use_thy "Chinese";
  5504 
  5505 
  5506 *** System ***
  5507 
  5508 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5509 isabelle, isatool etc.).
  5510 
  5511 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5512 isatool doc, isatool mkdir, display_drafts etc.).
  5513 
  5514 * isatool usedir: option -f allows specification of the ML file to be
  5515 used by Isabelle; default is ROOT.ML.
  5516 
  5517 * New isatool version outputs the version identifier of the Isabelle
  5518 distribution being used.
  5519 
  5520 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5521 (containing Boolean satisfiability problems) into Isabelle/HOL
  5522 theories.
  5523 
  5524 
  5525 
  5526 New in Isabelle2004 (April 2004)
  5527 --------------------------------
  5528 
  5529 *** General ***
  5530 
  5531 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5532   Replaces linorder.ML.
  5533 
  5534 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5535   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5536   (\<a>...\<z>), are now considered normal letters, and can therefore
  5537   be used anywhere where an ASCII letter (a...zA...Z) has until
  5538   now. COMPATIBILITY: This obviously changes the parsing of some
  5539   terms, especially where a symbol has been used as a binder, say
  5540   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5541   as an identifier.  Fix it by inserting a space around former
  5542   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5543   existing theory and ML files.
  5544 
  5545 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5546 
  5547 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5548   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5549   a normal (but invisible) letter. For multiple letter subscripts repeat
  5550   \<^isub> like this: x\<^isub>1\<^isub>2.
  5551 
  5552 * Pure: There are now sub-/superscripts that can span more than one
  5553   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5554   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5555   superscript. The new control characters are not identifier parts.
  5556 
  5557 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5558   content of "..." to the latex file instead of \isacntrl... . The "..."
  5559   may consist of any printable characters excluding the end bracket >.
  5560 
  5561 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5562   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5563   declare constants "final", which prevents their being given a definition
  5564   later.  It is useful for constants whose behaviour is fixed axiomatically
  5565   rather than definitionally, such as the meta-logic connectives.
  5566 
  5567 * Pure: 'instance' now handles general arities with general sorts
  5568   (i.e. intersections of classes),
  5569 
  5570 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5571   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5572   It can be changed to alter the colors/layout of generated pages.
  5573 
  5574 
  5575 *** Isar ***
  5576 
  5577 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5578   cut_tac, subgoal_tac and thin_tac:
  5579   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5580     locales are no longer forced to write Isar proof scripts.
  5581     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5582     emulations.
  5583   - INCOMPATIBILITY: names of variables to be instantiated may no
  5584     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5585     This is consistent with the instantiation attribute "where".
  5586 
  5587 * Attributes "where" and "of":
  5588   - Now take type variables of instantiated theorem into account when reading
  5589     the instantiation string.  This fixes a bug that caused instantiated
  5590     theorems to have too special types in some circumstances.
  5591   - "where" permits explicit instantiations of type variables.
  5592 
  5593 * Calculation commands "moreover" and "also" no longer interfere with
  5594   current facts ("this"), admitting arbitrary combinations with "then"
  5595   and derived forms.
  5596 
  5597 * Locales:
  5598   - Goal statements involving the context element "includes" no longer
  5599     generate theorems with internal delta predicates (those ending on
  5600     "_axioms") in the premise.
  5601     Resolve particular premise with <locale>.intro to obtain old form.
  5602   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5603     specification and "includes" elements in goal statement.
  5604   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5605     [intro?] and [elim?] (respectively) by default.
  5606   - Experimental command for instantiation of locales in proof contexts:
  5607         instantiate <label>[<attrs>]: <loc>
  5608     Instantiates locale <loc> and adds all its theorems to the current context
  5609     taking into account their attributes.  Label and attrs are optional
  5610     modifiers, like in theorem declarations.  If present, names of
  5611     instantiated theorems are qualified with <label>, and the attributes
  5612     <attrs> are applied after any attributes these theorems might have already.
  5613       If the locale has assumptions, a chained fact of the form
  5614     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5615     are derived.  The command does not support old-style locales declared
  5616     with "locale (open)".
  5617       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5618 
  5619 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5620   (Isar) contexts.
  5621 
  5622 
  5623 *** HOL ***
  5624 
  5625 * Proof import: new image HOL4 contains the imported library from
  5626   the HOL4 system with about 2500 theorems. It is imported by
  5627   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5628   can be used like any other Isabelle image.  See
  5629   HOL/Import/HOL/README for more information.
  5630 
  5631 * Simplifier:
  5632   - Much improved handling of linear and partial orders.
  5633     Reasoners for linear and partial orders are set up for type classes
  5634     "linorder" and "order" respectively, and are added to the default simpset
  5635     as solvers.  This means that the simplifier can build transitivity chains
  5636     to solve goals from the assumptions.
  5637   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5638     of blast or auto after simplification become unnecessary because the goal
  5639     is solved by simplification already.
  5640 
  5641 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5642     all proved in axiomatic type classes for semirings, rings and fields.
  5643 
  5644 * Numerics:
  5645   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5646     now formalized using the Ring_and_Field theory mentioned above.
  5647   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5648     than before, because now they are set up once in a generic manner.
  5649   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5650     Look for the general versions in Ring_and_Field (and Power if they concern
  5651     exponentiation).
  5652 
  5653 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5654 
  5655 * Records:
  5656   - Record types are now by default printed with their type abbreviation
  5657     instead of the list of all field types. This can be configured via
  5658     the reference "print_record_type_abbr".
  5659   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5660     (not enabled by default).
  5661   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5662     EX x. x = sel r to True (not enabled by default).
  5663   - Tactic "record_split_simp_tac" to split and simplify records added.
  5664 
  5665 * 'specification' command added, allowing for definition by
  5666   specification.  There is also an 'ax_specification' command that
  5667   introduces the new constants axiomatically.
  5668 
  5669 * arith(_tac) is now able to generate counterexamples for reals as well.
  5670 
  5671 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5672 
  5673 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5674   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5675 
  5676 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5677   matrix theory to linear programming.
  5678 
  5679 * Unions and Intersections:
  5680   The latex output syntax of UN and INT has been changed
  5681   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5682   i.e. the index formulae has become a subscript.
  5683   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5684 
  5685 * Unions and Intersections over Intervals:
  5686   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5687   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5688   like in normal math, and corresponding versions for < and for intersection.
  5689 
  5690 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5691   lexicographic dictonary ordering has been added as "lexord".
  5692 
  5693 * ML: the legacy theory structures Int and List have been removed. They had
  5694   conflicted with ML Basis Library structures having the same names.
  5695 
  5696 * 'refute' command added to search for (finite) countermodels.  Only works
  5697   for a fragment of HOL.  The installation of an external SAT solver is
  5698   highly recommended.  See "HOL/Refute.thy" for details.
  5699 
  5700 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5701   formulae under an assignment of free variables to random values.
  5702   In contrast to 'refute', it can deal with inductive datatypes,
  5703   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5704   for examples.
  5705 
  5706 
  5707 *** HOLCF ***
  5708 
  5709 * Streams now come with concatenation and are part of the HOLCF image
  5710 
  5711 
  5712 
  5713 New in Isabelle2003 (May 2003)
  5714 ------------------------------
  5715 
  5716 *** General ***
  5717 
  5718 * Provers/simplifier:
  5719 
  5720   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5721     Assumptions are now subject to complete mutual simplification,
  5722     not just from left to right. The simplifier now preserves
  5723     the order of assumptions.
  5724 
  5725     Potential INCOMPATIBILITY:
  5726 
  5727     -- simp sometimes diverges where the old version did
  5728        not, e.g. invoking simp on the goal
  5729 
  5730         [| P (f x); y = x; f x = f y |] ==> Q
  5731 
  5732        now gives rise to the infinite reduction sequence
  5733 
  5734         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5735 
  5736        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5737        kind of problem.
  5738 
  5739     -- Tactics combining classical reasoner and simplification (such as auto)
  5740        are also affected by this change, because many of them rely on
  5741        simp. They may sometimes diverge as well or yield a different numbers
  5742        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5743        in case of problems. Sometimes subsequent calls to the classical
  5744        reasoner will fail because a preceeding call to the simplifier too
  5745        eagerly simplified the goal, e.g. deleted redundant premises.
  5746 
  5747   - The simplifier trace now shows the names of the applied rewrite rules
  5748 
  5749   - You can limit the number of recursive invocations of the simplifier
  5750     during conditional rewriting (where the simplifie tries to solve the
  5751     conditions before applying the rewrite rule):
  5752     ML "simp_depth_limit := n"
  5753     where n is an integer. Thus you can force termination where previously
  5754     the simplifier would diverge.
  5755 
  5756   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5757 
  5758   - No longer aborts on failed congruence proof.  Instead, the
  5759     congruence is ignored.
  5760 
  5761 * Pure: New generic framework for extracting programs from constructive
  5762   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5763   as HOL/Extraction for some case studies.
  5764 
  5765 * Pure: The main goal of the proof state is no longer shown by default, only
  5766 the subgoals. This behaviour is controlled by a new flag.
  5767    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5768 (ML: Proof.show_main_goal).
  5769 
  5770 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5771 rules whose conclusion matches subgoal 1:
  5772       PG menu: Isabelle/Isar -> Show me -> matching rules
  5773 The rules are ordered by how closely they match the subgoal.
  5774 In particular, rules that solve a subgoal outright are displayed first
  5775 (or rather last, the way they are printed).
  5776 (ML: ProofGeneral.print_intros())
  5777 
  5778 * Pure: New flag trace_unify_fail causes unification to print
  5779 diagnostic information (PG: in trace buffer) when it fails. This is
  5780 useful for figuring out why single step proofs like rule, erule or
  5781 assumption failed.
  5782 
  5783 * Pure: Locale specifications now produce predicate definitions
  5784 according to the body of text (covering assumptions modulo local
  5785 definitions); predicate "loc_axioms" covers newly introduced text,
  5786 while "loc" is cumulative wrt. all included locale expressions; the
  5787 latter view is presented only on export into the global theory
  5788 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5789 on the old view without predicates;
  5790 
  5791 * Pure: predefined locales "var" and "struct" are useful for sharing
  5792 parameters (as in CASL, for example); just specify something like
  5793 ``var x + var y + struct M'' as import;
  5794 
  5795 * Pure: improved thms_containing: proper indexing of facts instead of
  5796 raw theorems; check validity of results wrt. current name space;
  5797 include local facts of proof configuration (also covers active
  5798 locales), cover fixed variables in index; may use "_" in term
  5799 specification; an optional limit for the number of printed facts may
  5800 be given (the default is 40);
  5801 
  5802 * Pure: disallow duplicate fact bindings within new-style theory files
  5803 (batch-mode only);
  5804 
  5805 * Provers: improved induct method: assumptions introduced by case
  5806 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5807 the goal statement); "foo" still refers to all facts collectively;
  5808 
  5809 * Provers: the function blast.overloaded has been removed: all constants
  5810 are regarded as potentially overloaded, which improves robustness in exchange
  5811 for slight decrease in efficiency;
  5812 
  5813 * Provers/linorder: New generic prover for transitivity reasoning over
  5814 linear orders.  Note: this prover is not efficient!
  5815 
  5816 * Isar: preview of problems to finish 'show' now produce an error
  5817 rather than just a warning (in interactive mode);
  5818 
  5819 
  5820 *** HOL ***
  5821 
  5822 * arith(_tac)
  5823 
  5824  - Produces a counter example if it cannot prove a goal.
  5825    Note that the counter example may be spurious if the goal is not a formula
  5826    of quantifier-free linear arithmetic.
  5827    In ProofGeneral the counter example appears in the trace buffer.
  5828 
  5829  - Knows about div k and mod k where k is a numeral of type nat or int.
  5830 
  5831  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5832    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5833    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5834 
  5835 * simp's arithmetic capabilities have been enhanced a bit: it now
  5836 takes ~= in premises into account (by performing a case split);
  5837 
  5838 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5839 are distributed over a sum of terms;
  5840 
  5841 * New tactic "trans_tac" and method "trans" instantiate
  5842 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5843 "<=", "<" and "=").
  5844 
  5845 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5846 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5847 
  5848 * 'typedef' command has new option "open" to suppress the set
  5849 definition;
  5850 
  5851 * functions Min and Max on finite sets have been introduced (theory
  5852 Finite_Set);
  5853 
  5854 * attribute [symmetric] now works for relations as well; it turns
  5855 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5856 
  5857 * induct over a !!-quantified statement (say !!x1..xn):
  5858   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5859 
  5860 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5861 %x. None. Warning: empty_def now refers to the previously hidden definition
  5862 of the empty set.
  5863 
  5864 * Algebra: formalization of classical algebra.  Intended as base for
  5865 any algebraic development in Isabelle.  Currently covers group theory
  5866 (up to Sylow's theorem) and ring theory (Universal Property of
  5867 Univariate Polynomials).  Contributions welcome;
  5868 
  5869 * GroupTheory: deleted, since its material has been moved to Algebra;
  5870 
  5871 * Complex: new directory of the complex numbers with numeric constants,
  5872 nonstandard complex numbers, and some complex analysis, standard and
  5873 nonstandard (Jacques Fleuriot);
  5874 
  5875 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5876 
  5877 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5878 Fleuriot);
  5879 
  5880 * Real/HahnBanach: updated and adapted to locales;
  5881 
  5882 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5883 Gray and Kramer);
  5884 
  5885 * UNITY: added the Meier-Sanders theory of progress sets;
  5886 
  5887 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5888 as abstract algorithms, instantiated to the JVM;
  5889 
  5890 * Bali: Java source language formalization. Type system, operational
  5891 semantics, axiomatic semantics. Supported language features:
  5892 classes, interfaces, objects,virtual methods, static methods,
  5893 static/instance fields, arrays, access modifiers, definite
  5894 assignment, exceptions.
  5895 
  5896 
  5897 *** ZF ***
  5898 
  5899 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5900 universe, etc.);
  5901 
  5902 * Main ZF: virtually all theories converted to new-style format;
  5903 
  5904 
  5905 *** ML ***
  5906 
  5907 * Pure: Tactic.prove provides sane interface for internal proofs;
  5908 omits the infamous "standard" operation, so this is more appropriate
  5909 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5910 
  5911 * Pure: improved error reporting of simprocs;
  5912 
  5913 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5914 up simprocs;
  5915 
  5916 
  5917 *** Document preparation ***
  5918 
  5919 * uses \par instead of \\ for line breaks in theory text. This may
  5920 shift some page breaks in large documents. To get the old behaviour
  5921 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5922 
  5923 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5924 other packages
  5925 
  5926 * \<euro> now needs package babel/greek instead of marvosym (which
  5927 broke \Rightarrow)
  5928 
  5929 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5930 textcomp package)
  5931 
  5932 
  5933 
  5934 New in Isabelle2002 (March 2002)
  5935 --------------------------------
  5936 
  5937 *** Document preparation ***
  5938 
  5939 * greatly simplified document preparation setup, including more
  5940 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5941 instructive isatool mkdir; users should basically be able to get
  5942 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5943 users may run a separate document processing stage manually like this:
  5944 "isatool usedir -D output HOL Test && isatool document Test/output";
  5945 
  5946 * theory dependency graph may now be incorporated into documents;
  5947 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5948 with \includegraphics of LaTeX;
  5949 
  5950 * proper spacing of consecutive markup elements, especially text
  5951 blocks after section headings;
  5952 
  5953 * support bold style (for single symbols only), input syntax is like
  5954 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5955 
  5956 * \<bullet> is now output as bold \cdot by default, which looks much
  5957 better in printed text;
  5958 
  5959 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5960 note that these symbols are currently unavailable in Proof General /
  5961 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5962 
  5963 * isatool latex no longer depends on changed TEXINPUTS, instead
  5964 isatool document copies the Isabelle style files to the target
  5965 location;
  5966 
  5967 
  5968 *** Isar ***
  5969 
  5970 * Pure/Provers: improved proof by cases and induction;
  5971   - 'case' command admits impromptu naming of parameters (such as
  5972     "case (Suc n)");
  5973   - 'induct' method divinates rule instantiation from the inductive
  5974     claim; no longer requires excessive ?P bindings for proper
  5975     instantiation of cases;
  5976   - 'induct' method properly enumerates all possibilities of set/type
  5977     rules; as a consequence facts may be also passed through *type*
  5978     rules without further ado;
  5979   - 'induct' method now derives symbolic cases from the *rulified*
  5980     rule (before it used to rulify cases stemming from the internal
  5981     atomized version); this means that the context of a non-atomic
  5982     statement becomes is included in the hypothesis, avoiding the
  5983     slightly cumbersome show "PROP ?case" form;
  5984   - 'induct' may now use elim-style induction rules without chaining
  5985     facts, using ``missing'' premises from the goal state; this allows
  5986     rules stemming from inductive sets to be applied in unstructured
  5987     scripts, while still benefitting from proper handling of non-atomic
  5988     statements; NB: major inductive premises need to be put first, all
  5989     the rest of the goal is passed through the induction;
  5990   - 'induct' proper support for mutual induction involving non-atomic
  5991     rule statements (uses the new concept of simultaneous goals, see
  5992     below);
  5993   - append all possible rule selections, but only use the first
  5994     success (no backtracking);
  5995   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5996   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5997   - added 'print_induct_rules' (covered by help item in recent Proof
  5998     General versions);
  5999   - moved induct/cases attributes to Pure, methods to Provers;
  6000   - generic method setup instantiated for FOL and HOL;
  6001 
  6002 * Pure: support multiple simultaneous goal statements, for example
  6003 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6004 meta-level mechanism, this acts as if several individual goals had
  6005 been stated separately; in particular common proof methods need to be
  6006 repeated in order to cover all claims; note that a single elimination
  6007 step is *not* sufficient to establish the two conjunctions, so this
  6008 fails:
  6009 
  6010   assume "A & B" then have A and B ..   (*".." fails*)
  6011 
  6012 better use "obtain" in situations as above; alternative refer to
  6013 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6014 
  6015 * Pure: proper integration with ``locales''; unlike the original
  6016 version by Florian Kammller, Isar locales package high-level proof
  6017 contexts rather than raw logical ones (e.g. we admit to include
  6018 attributes everywhere); operations on locales include merge and
  6019 rename; support for implicit arguments (``structures''); simultaneous
  6020 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6021 some examples;
  6022 
  6023 * Pure: the following commands have been ``localized'', supporting a
  6024 target locale specification "(in name)": 'lemma', 'theorem',
  6025 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6026 stored both within the locale and at the theory level (exported and
  6027 qualified by the locale name);
  6028 
  6029 * Pure: theory goals may now be specified in ``long'' form, with
  6030 ad-hoc contexts consisting of arbitrary locale elements. for example
  6031 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6032 definitions may be given, too); the result is a meta-level rule with
  6033 the context elements being discharged in the obvious way;
  6034 
  6035 * Pure: new proof command 'using' allows to augment currently used
  6036 facts after a goal statement ('using' is syntactically analogous to
  6037 'apply', but acts on the goal's facts only); this allows chained facts
  6038 to be separated into parts given before and after a claim, as in
  6039 ``from a and b have C using d and e <proof>'';
  6040 
  6041 * Pure: renamed "antecedent" case to "rule_context";
  6042 
  6043 * Pure: new 'judgment' command records explicit information about the
  6044 object-logic embedding (used by several tools internally); no longer
  6045 use hard-wired "Trueprop";
  6046 
  6047 * Pure: added 'corollary' command;
  6048 
  6049 * Pure: fixed 'token_translation' command;
  6050 
  6051 * Pure: removed obsolete 'exported' attribute;
  6052 
  6053 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6054 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6055 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6056 
  6057 * Pure: method 'atomize' presents local goal premises as object-level
  6058 statements (atomic meta-level propositions); setup controlled via
  6059 rewrite rules declarations of 'atomize' attribute; example
  6060 application: 'induct' method with proper rule statements in improper
  6061 proof *scripts*;
  6062 
  6063 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6064 now consider the syntactic context of assumptions, giving a better
  6065 chance to get type-inference of the arguments right (this is
  6066 especially important for locales);
  6067 
  6068 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6069 mode;
  6070 
  6071 * Pure/obtain: the formal conclusion "thesis", being marked as
  6072 ``internal'', may no longer be reference directly in the text;
  6073 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6074 situations;
  6075 
  6076 * Pure: generic 'sym' attribute which declares a rule both as pure
  6077 'elim?' and for the 'symmetric' operation;
  6078 
  6079 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6080 text; the fixed correlation with particular command syntax has been
  6081 discontinued;
  6082 
  6083 * Pure: new method 'rules' is particularly well-suited for proof
  6084 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6085 but often produces more compact proof terms with less detours;
  6086 
  6087 * Pure/Provers/classical: simplified integration with pure rule
  6088 attributes and methods; the classical "intro?/elim?/dest?"
  6089 declarations coincide with the pure ones; the "rule" method no longer
  6090 includes classically swapped intros; "intro" and "elim" methods no
  6091 longer pick rules from the context; also got rid of ML declarations
  6092 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6093 INCOMPATIBILITY;
  6094 
  6095 * Provers/classical: attribute 'swapped' produces classical inversions
  6096 of introduction rules;
  6097 
  6098 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6099 rules instead of full simplifier context; 'iff' attribute handles
  6100 conditional rules;
  6101 
  6102 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6103 
  6104 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6105 "(permissive)" option to recover old behavior;
  6106 
  6107 * HOL: 'inductive' no longer features separate (collective) attributes
  6108 for 'intros' (was found too confusing);
  6109 
  6110 * HOL: properly declared induction rules less_induct and
  6111 wf_induct_rule;
  6112 
  6113 
  6114 *** HOL ***
  6115 
  6116 * HOL: moved over to sane numeral syntax; the new policy is as
  6117 follows:
  6118 
  6119   - 0 and 1 are polymorphic constants, which are defined on any
  6120   numeric type (nat, int, real etc.);
  6121 
  6122   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6123   binary representation internally;
  6124 
  6125   - type nat has special constructor Suc, and generally prefers Suc 0
  6126   over 1::nat and Suc (Suc 0) over 2::nat;
  6127 
  6128 This change may cause significant problems of INCOMPATIBILITY; here
  6129 are some hints on converting existing sources:
  6130 
  6131   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6132   entities, so expressions involving "-" (unary or binary minus) need
  6133   to be spaced properly;
  6134 
  6135   - existing occurrences of "1" may need to be constraint "1::nat" or
  6136   even replaced by Suc 0; similar for old "2";
  6137 
  6138   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6139 
  6140   - remove all special provisions on numerals in proofs;
  6141 
  6142 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6143 representation (depends on bin_arith_simps in the default context);
  6144 
  6145 * HOL: symbolic syntax for x^2 (numeral 2);
  6146 
  6147 * HOL: the class of all HOL types is now called "type" rather than
  6148 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6149 in axclass/classes, instance/arities, and (usually rare) occurrences
  6150 in typings (of consts etc.); internally the class is called
  6151 "HOL.type", ML programs should refer to HOLogic.typeS;
  6152 
  6153 * HOL/record package improvements:
  6154   - new derived operations "fields" to build a partial record section,
  6155     "extend" to promote a fixed record to a record scheme, and
  6156     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6157     declared as simp by default;
  6158   - shared operations ("more", "fields", etc.) now need to be always
  6159     qualified) --- potential INCOMPATIBILITY;
  6160   - removed "make_scheme" operations (use "make" with "extend") --
  6161     INCOMPATIBILITY;
  6162   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6163   - provides cases/induct rules for use with corresponding Isar
  6164     methods (for concrete records, record schemes, concrete more
  6165     parts, and schematic more parts -- in that order);
  6166   - internal definitions directly based on a light-weight abstract
  6167     theory of product types over typedef rather than datatype;
  6168 
  6169 * HOL: generic code generator for generating executable ML code from
  6170 specifications; specific support for HOL constructs such as inductive
  6171 datatypes and sets, as well as recursive functions; can be invoked
  6172 via 'generate_code' theory section;
  6173 
  6174 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6175 
  6176 * HOL: consolidated and renamed several theories.  In particular:
  6177         Ord.thy has been absorbed into HOL.thy
  6178         String.thy has been absorbed into List.thy
  6179 
  6180 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6181 (beware of argument permutation!);
  6182 
  6183 * HOL: linorder_less_split superseded by linorder_cases;
  6184 
  6185 * HOL/List: "nodups" renamed to "distinct";
  6186 
  6187 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6188 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6189   - Ex_def has changed, now need to use some_eq_ex
  6190 
  6191 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6192 in this (rare) case use:
  6193 
  6194   delSWrapper "split_all_tac"
  6195   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6196 
  6197 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6198 MAY FAIL;
  6199 
  6200 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  6201 Isabelle's type classes, ^ on functions and relations has too general
  6202 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  6203 necessary to attach explicit type constraints;
  6204 
  6205 * HOL/Relation: the prefix name of the infix "O" has been changed from
  6206 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  6207 renamed accordingly (eg "compI" -> "rel_compI").
  6208 
  6209 * HOL: syntax translations now work properly with numerals and records
  6210 expressions;
  6211 
  6212 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  6213 of "lam" -- INCOMPATIBILITY;
  6214 
  6215 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  6216 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  6217 renamed "Product_Type.unit";
  6218 
  6219 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  6220 
  6221 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  6222 the "cases" method);
  6223 
  6224 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  6225 Florian Kammller);
  6226 
  6227 * HOL/IMP: updated and converted to new-style theory format; several
  6228 parts turned into readable document, with proper Isar proof texts and
  6229 some explanations (by Gerwin Klein);
  6230 
  6231 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  6232 
  6233 * HOL-Hyperreal is now a logic image;
  6234 
  6235 
  6236 *** HOLCF ***
  6237 
  6238 * Isar: consts/constdefs supports mixfix syntax for continuous
  6239 operations;
  6240 
  6241 * Isar: domain package adapted to new-style theory format, e.g. see
  6242 HOLCF/ex/Dnat.thy;
  6243 
  6244 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  6245 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  6246 lift.induct_tac, always use UU instead of Undef;
  6247 
  6248 * HOLCF/IMP: updated and converted to new-style theory;
  6249 
  6250 
  6251 *** ZF ***
  6252 
  6253 * Isar: proper integration of logic-specific tools and packages,
  6254 including theory commands '(co)inductive', '(co)datatype',
  6255 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  6256 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  6257 
  6258 * theory Main no longer includes AC; for the Axiom of Choice, base
  6259 your theory on Main_ZFC;
  6260 
  6261 * the integer library now covers quotients and remainders, with many
  6262 laws relating division to addition, multiplication, etc.;
  6263 
  6264 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  6265 typeless version of the formalism;
  6266 
  6267 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  6268 format;
  6269 
  6270 * ZF/Induct: new directory for examples of inductive definitions,
  6271 including theory Multiset for multiset orderings; converted to
  6272 new-style theory format;
  6273 
  6274 * ZF: many new theorems about lists, ordinals, etc.;
  6275 
  6276 
  6277 *** General ***
  6278 
  6279 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  6280 variable proof controls level of detail: 0 = no proofs (only oracle
  6281 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  6282 also ref manual for further ML interfaces;
  6283 
  6284 * Pure/axclass: removed obsolete ML interface
  6285 goal_subclass/goal_arity;
  6286 
  6287 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  6288 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  6289 separate tokens, so expressions involving minus need to be spaced
  6290 properly;
  6291 
  6292 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  6293 rather than "infixl" or "infixr";
  6294 
  6295 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  6296 sort constraint specifications in type inference; e.g. "x::_::foo"
  6297 ensures that the type of "x" is of sort "foo" (but not necessarily a
  6298 type variable);
  6299 
  6300 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  6301 control output of nested => (types); the default behavior is
  6302 "type_brackets";
  6303 
  6304 * Pure/syntax: builtin parse translation for "_constify" turns valued
  6305 tokens into AST constants;
  6306 
  6307 * Pure/syntax: prefer later declarations of translations and print
  6308 translation functions; potential INCOMPATIBILITY: need to reverse
  6309 multiple declarations for same syntax element constant;
  6310 
  6311 * Pure/show_hyps reset by default (in accordance to existing Isar
  6312 practice);
  6313 
  6314 * Provers/classical: renamed addaltern to addafter, addSaltern to
  6315 addSafter;
  6316 
  6317 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  6318 as well;
  6319 
  6320 * system: tested support for MacOS X; should be able to get Isabelle +
  6321 Proof General to work in a plain Terminal after installing Poly/ML
  6322 (e.g. from the Isabelle distribution area) and GNU bash alone
  6323 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  6324 support requires further installations, e.g. from
  6325 http://fink.sourceforge.net/);
  6326 
  6327 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  6328 
  6329 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  6330 of 40 MB), cf. ML_OPTIONS;
  6331 
  6332 * system: Proof General keywords specification is now part of the
  6333 Isabelle distribution (see etc/isar-keywords.el);
  6334 
  6335 * system: support for persistent Proof General sessions (refrain from
  6336 outdating all loaded theories on startup); user may create writable
  6337 logic images like this: ``isabelle -q HOL Test'';
  6338 
  6339 * system: smart selection of Isabelle process versus Isabelle
  6340 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  6341 run both "isabelle" and "Isabelle" even if file names are badly
  6342 damaged (executable inspects the case of the first letter of its own
  6343 name); added separate "isabelle-process" and "isabelle-interface";
  6344 
  6345 * system: refrain from any attempt at filtering input streams; no
  6346 longer support ``8bit'' encoding of old isabelle font, instead proper
  6347 iso-latin characters may now be used; the related isatools
  6348 "symbolinput" and "nonascii" have disappeared as well;
  6349 
  6350 * system: removed old "xterm" interface (the print modes "xterm" and
  6351 "xterm_color" are still available for direct use in a suitable
  6352 terminal);
  6353 
  6354 
  6355 
  6356 New in Isabelle99-2 (February 2001)
  6357 -----------------------------------
  6358 
  6359 *** Overview of INCOMPATIBILITIES ***
  6360 
  6361 * HOL: please note that theories in the Library and elsewhere often use the
  6362 new-style (Isar) format; to refer to their theorems in an ML script you must
  6363 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  6364 
  6365 * HOL: inductive package no longer splits induction rule aggressively,
  6366 but only as far as specified by the introductions given; the old
  6367 format may be recovered via ML function complete_split_rule or attribute
  6368 'split_rule (complete)';
  6369 
  6370 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  6371 gfp_Tarski to gfp_unfold;
  6372 
  6373 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  6374 
  6375 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  6376 relation); infix "^^" has been renamed "``"; infix "``" has been
  6377 renamed "`"; "univalent" has been renamed "single_valued";
  6378 
  6379 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  6380 operation;
  6381 
  6382 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  6383 
  6384 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  6385 
  6386 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  6387 consequence, it is no longer monotonic wrt. the local goal context
  6388 (which is now passed through the inductive cases);
  6389 
  6390 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  6391 \<gg> to \<ggreater>;
  6392 
  6393 
  6394 *** Document preparation ***
  6395 
  6396 * \isabellestyle{NAME} selects version of Isabelle output (currently
  6397 available: are "it" for near math-mode best-style output, "sl" for
  6398 slanted text style, and "tt" for plain type-writer; if no
  6399 \isabellestyle command is given, output is according to slanted
  6400 type-writer);
  6401 
  6402 * support sub/super scripts (for single symbols only), input syntax is
  6403 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  6404 
  6405 * some more standard symbols; see Appendix A of the system manual for
  6406 the complete list of symbols defined in isabellesym.sty;
  6407 
  6408 * improved isabelle style files; more abstract symbol implementation
  6409 (should now use \isamath{...} and \isatext{...} in custom symbol
  6410 definitions);
  6411 
  6412 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  6413 state; Note that presentation of goal states does not conform to
  6414 actual human-readable proof documents.  Please do not include goal
  6415 states into document output unless you really know what you are doing!
  6416 
  6417 * proper indentation of antiquoted output with proportional LaTeX
  6418 fonts;
  6419 
  6420 * no_document ML operator temporarily disables LaTeX document
  6421 generation;
  6422 
  6423 * isatool unsymbolize tunes sources for plain ASCII communication;
  6424 
  6425 
  6426 *** Isar ***
  6427 
  6428 * Pure: Isar now suffers initial goal statements to contain unbound
  6429 schematic variables (this does not conform to actual readable proof
  6430 documents, due to unpredictable outcome and non-compositional proof
  6431 checking); users who know what they are doing may use schematic goals
  6432 for Prolog-style synthesis of proven results;
  6433 
  6434 * Pure: assumption method (an implicit finishing) now handles actual
  6435 rules as well;
  6436 
  6437 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  6438 initial goal, declare "that" only as Pure intro (only for single
  6439 steps); the "that" rule assumption may now be involved in implicit
  6440 finishing, thus ".." becomes a feasible for trivial obtains;
  6441 
  6442 * Pure: default proof step now includes 'intro_classes'; thus trivial
  6443 instance proofs may be performed by "..";
  6444 
  6445 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  6446 statements as well;
  6447 
  6448 * Pure: more robust selection of calculational rules;
  6449 
  6450 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  6451 rule (as well as the assumption rule);
  6452 
  6453 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  6454 lemmas, using the graph browser tool;
  6455 
  6456 * Pure: predict failure of "show" in interactive mode;
  6457 
  6458 * Pure: 'thms_containing' now takes actual terms as arguments;
  6459 
  6460 * HOL: improved method 'induct' --- now handles non-atomic goals
  6461 (potential INCOMPATIBILITY); tuned error handling;
  6462 
  6463 * HOL: cases and induct rules now provide explicit hints about the
  6464 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  6465 any remaining facts are inserted into the goal verbatim;
  6466 
  6467 * HOL: local contexts (aka cases) may now contain term bindings as
  6468 well; the 'cases' and 'induct' methods new provide a ?case binding for
  6469 the result to be shown in each case;
  6470 
  6471 * HOL: added 'recdef_tc' command;
  6472 
  6473 * isatool convert assists in eliminating legacy ML scripts;
  6474 
  6475 
  6476 *** HOL ***
  6477 
  6478 * HOL/Library: a collection of generic theories to be used together
  6479 with main HOL; the theory loader path already includes this directory
  6480 by default; the following existing theories have been moved here:
  6481 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  6482 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  6483 
  6484 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  6485 modelling and verification task performed in Isabelle/HOL +
  6486 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  6487 
  6488 * HOL/Algebra: special summation operator SUM no longer exists, it has
  6489 been replaced by setsum; infix 'assoc' now has priority 50 (like
  6490 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  6491 'domain', this makes the theory consistent with mathematical
  6492 literature;
  6493 
  6494 * HOL basics: added overloaded operations "inverse" and "divide"
  6495 (infix "/"), syntax for generic "abs" operation, generic summation
  6496 operator \<Sum>;
  6497 
  6498 * HOL/typedef: simplified package, provide more useful rules (see also
  6499 HOL/subset.thy);
  6500 
  6501 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  6502 now expressed as a proper nested rule (old-style tactic scripts may
  6503 require atomize_strip_tac to cope with non-atomic premises);
  6504 
  6505 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  6506 to "split_conv" (old name still available for compatibility);
  6507 
  6508 * HOL: improved concrete syntax for strings (e.g. allows translation
  6509 rules with string literals);
  6510 
  6511 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  6512  and Fleuriot's mechanization of analysis, including the transcendental
  6513  functions for the reals;
  6514 
  6515 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  6516 
  6517 
  6518 *** CTT ***
  6519 
  6520 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  6521 "lam" is displayed as TWO lambda-symbols
  6522 
  6523 * CTT: theory Main now available, containing everything (that is, Bool
  6524 and Arith);
  6525 
  6526 
  6527 *** General ***
  6528 
  6529 * Pure: the Simplifier has been implemented properly as a derived rule
  6530 outside of the actual kernel (at last!); the overall performance
  6531 penalty in practical applications is about 50%, while reliability of
  6532 the Isabelle inference kernel has been greatly improved;
  6533 
  6534 * print modes "brackets" and "no_brackets" control output of nested =>
  6535 (types) and ==> (props); the default behaviour is "brackets";
  6536 
  6537 * Provers: fast_tac (and friends) now handle actual object-logic rules
  6538 as assumptions as well;
  6539 
  6540 * system: support Poly/ML 4.0;
  6541 
  6542 * system: isatool install handles KDE version 1 or 2;
  6543 
  6544 
  6545 
  6546 New in Isabelle99-1 (October 2000)
  6547 ----------------------------------
  6548 
  6549 *** Overview of INCOMPATIBILITIES ***
  6550 
  6551 * HOL: simplification of natural numbers is much changed; to partly
  6552 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  6553 issue the following ML commands:
  6554 
  6555   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  6556   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  6557 
  6558 * HOL: simplification no longer dives into case-expressions; this is
  6559 controlled by "t.weak_case_cong" for each datatype t;
  6560 
  6561 * HOL: nat_less_induct renamed to less_induct;
  6562 
  6563 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  6564 fixsome to patch .thy and .ML sources automatically;
  6565 
  6566   select_equality  -> some_equality
  6567   select_eq_Ex     -> some_eq_ex
  6568   selectI2EX       -> someI2_ex
  6569   selectI2         -> someI2
  6570   selectI          -> someI
  6571   select1_equality -> some1_equality
  6572   Eps_sym_eq       -> some_sym_eq_trivial
  6573   Eps_eq           -> some_eq_trivial
  6574 
  6575 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  6576 
  6577 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  6578 instead);
  6579 
  6580 * HOL: the recursion equations generated by 'recdef' are now called
  6581 f.simps instead of f.rules;
  6582 
  6583 * HOL: qed_spec_mp now also handles bounded ALL as well;
  6584 
  6585 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  6586 sometimes be needed;
  6587 
  6588 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  6589 
  6590 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  6591 
  6592 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  6593 product is now "<*>" instead of "Times"; the lexicographic product is
  6594 now "<*lex*>" instead of "**";
  6595 
  6596 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  6597 of main HOL, but was unused); better use HOL's datatype package;
  6598 
  6599 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6600 the old syntax may be recovered as follows:
  6601 
  6602   syntax (symbols)
  6603     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6604       (infixl "\\<oplus>" 100)
  6605 
  6606 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6607 
  6608 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6609 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6610 internally;
  6611 
  6612 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6613 changed from A/r to A//r;
  6614 
  6615 * ZF: new treatment of arithmetic (nat & int) may break some old
  6616 proofs;
  6617 
  6618 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6619 rulify -> rule_format, elimify -> elim_format, ...);
  6620 
  6621 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6622 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6623 should have to change intro!! to intro? only); replaced "delrule" by
  6624 "rule del";
  6625 
  6626 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6627 
  6628 * Provers: strengthened force_tac by using new first_best_tac;
  6629 
  6630 * LaTeX document preparation: several changes of isabelle.sty (see
  6631 lib/texinputs);
  6632 
  6633 
  6634 *** Document preparation ***
  6635 
  6636 * formal comments (text blocks etc.) in new-style theories may now
  6637 contain antiquotations of thm/prop/term/typ/text to be presented
  6638 according to latex print mode; concrete syntax is like this:
  6639 @{term[show_types] "f(x) = a + x"};
  6640 
  6641 * isatool mkdir provides easy setup of Isabelle session directories,
  6642 including proper document sources;
  6643 
  6644 * generated LaTeX sources are now deleted after successful run
  6645 (isatool document -c); may retain a copy somewhere else via -D option
  6646 of isatool usedir;
  6647 
  6648 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6649 style files, achieving self-contained LaTeX sources and simplifying
  6650 LaTeX debugging;
  6651 
  6652 * old-style theories now produce (crude) LaTeX output as well;
  6653 
  6654 * browser info session directories are now self-contained (may be put
  6655 on WWW server seperately); improved graphs of nested sessions; removed
  6656 graph for 'all sessions';
  6657 
  6658 * several improvements in isabelle style files; \isabellestyle{it}
  6659 produces fake math mode output; \isamarkupheader is now \section by
  6660 default; see lib/texinputs/isabelle.sty etc.;
  6661 
  6662 
  6663 *** Isar ***
  6664 
  6665 * Isar/Pure: local results and corresponding term bindings are now
  6666 subject to Hindley-Milner polymorphism (similar to ML); this
  6667 accommodates incremental type-inference very nicely;
  6668 
  6669 * Isar/Pure: new derived language element 'obtain' supports
  6670 generalized existence reasoning;
  6671 
  6672 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6673 support accumulation of results, without applying any rules yet;
  6674 useful to collect intermediate results without explicit name
  6675 references, and for use with transitivity rules with more than 2
  6676 premises;
  6677 
  6678 * Isar/Pure: scalable support for case-analysis type proofs: new
  6679 'case' language element refers to local contexts symbolically, as
  6680 produced by certain proof methods; internally, case names are attached
  6681 to theorems as "tags";
  6682 
  6683 * Isar/Pure: theory command 'hide' removes declarations from
  6684 class/type/const name spaces;
  6685 
  6686 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6687 indicate potential overloading;
  6688 
  6689 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6690 
  6691 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6692 "{a,b,c}" instead of {a,b,c};
  6693 
  6694 * Isar/Pure now provides its own version of intro/elim/dest
  6695 attributes; useful for building new logics, but beware of confusion
  6696 with the version in Provers/classical;
  6697 
  6698 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6699 case name 'antecedent';
  6700 
  6701 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6702 to the current context is now done automatically);
  6703 
  6704 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6705 for definining proof methods in ML;
  6706 
  6707 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6708 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6709 most cases, one should have to change intro!! to intro? only);
  6710 replaced "delrule" by "rule del";
  6711 
  6712 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6713 'symmetric' attribute (the latter supercedes [RS sym]);
  6714 
  6715 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6716 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6717 well (including splits);
  6718 
  6719 * Isar/Provers: Simplifier and Classical methods now support all kind
  6720 of modifiers used in the past, including 'cong', 'iff', etc.
  6721 
  6722 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6723 of Simplifier and Classical reasoner);
  6724 
  6725 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6726 now support named cases; major packages (inductive, datatype, primrec,
  6727 recdef) support case names and properly name parameters;
  6728 
  6729 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6730 monotonicity conditions are extracted to be proven at end of
  6731 calculations;
  6732 
  6733 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6734 method anyway;
  6735 
  6736 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6737 split_if split_if_asm; datatype package provides theorems foo.splits =
  6738 foo.split foo.split_asm for each datatype;
  6739 
  6740 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6741 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6742 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6743 use "(cases (simplified))" method in proper proof texts);
  6744 
  6745 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6746 
  6747 * Isar: names of theorems etc. may be natural numbers as well;
  6748 
  6749 * Isar: 'pr' command: optional arguments for goals_limit and
  6750 ProofContext.prems_limit; no longer prints theory contexts, but only
  6751 proof states;
  6752 
  6753 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6754 additional print modes to be specified; e.g. "pr(latex)" will print
  6755 proof state according to the Isabelle LaTeX style;
  6756 
  6757 * Isar: improved support for emulating tactic scripts, including proof
  6758 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6759 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6760 (for HOL datatypes);
  6761 
  6762 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6763 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6764 'proof method scripts' have to be in depth-first order;
  6765 
  6766 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6767 
  6768 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6769 should instead use individual commands for printing items
  6770 (print_commands, print_methods etc.);
  6771 
  6772 * Isar: added 'nothing' --- the empty list of theorems;
  6773 
  6774 
  6775 *** HOL ***
  6776 
  6777 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6778 corresponding virtual machine and a specification of its bytecode
  6779 verifier and a lightweight bytecode verifier, including proofs of
  6780 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6781 Cornelia Pusch (see also the homepage of project Bali at
  6782 http://isabelle.in.tum.de/Bali/);
  6783 
  6784 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6785 Clemens Ballarin;
  6786 
  6787 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6788 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6789 Rasmussen;
  6790 
  6791 * HOL/Lattice: fundamental concepts of lattice theory and order
  6792 structures, including duals, properties of bounds versus algebraic
  6793 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6794 Theorem for complete lattices etc.; may also serve as a demonstration
  6795 for abstract algebraic reasoning using axiomatic type classes, and
  6796 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6797 
  6798 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6799 von Oheimb;
  6800 
  6801 * HOL/IMPP: extension of IMP with local variables and mutually
  6802 recursive procedures, by David von Oheimb;
  6803 
  6804 * HOL/Lambda: converted into new-style theory and document;
  6805 
  6806 * HOL/ex/Multiquote: example of multiple nested quotations and
  6807 anti-quotations -- basically a generalized version of de-Bruijn
  6808 representation; very useful in avoiding lifting of operations;
  6809 
  6810 * HOL/record: added general record equality rule to simpset; fixed
  6811 select-update simplification procedure to handle extended records as
  6812 well; admit "r" as field name;
  6813 
  6814 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6815 other numeric types and also as the identity of groups, rings, etc.;
  6816 
  6817 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6818 Types nat and int belong to this axclass;
  6819 
  6820 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6821    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6822    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6823   two terms #m*u and #n*u are replaced by #(m+n)*u
  6824     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6825   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6826     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6827 
  6828 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6829 powerful prover for predicate logic but knows nothing of clasets; see
  6830 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6831 
  6832 * HOL: new version of "case_tac" subsumes both boolean case split and
  6833 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6834 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6835 
  6836 * HOL: simplification no longer dives into case-expressions: only the
  6837 selector expression is simplified, but not the remaining arms; to
  6838 enable full simplification of case-expressions for datatype t, you may
  6839 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6840 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6841 
  6842 * HOL/recdef: the recursion equations generated by 'recdef' for
  6843 function 'f' are now called f.simps instead of f.rules; if all
  6844 termination conditions are proved automatically, these simplification
  6845 rules are added to the simpset, as in primrec; rules may be named
  6846 individually as well, resulting in a separate list of theorems for
  6847 each equation;
  6848 
  6849 * HOL/While is a new theory that provides a while-combinator. It
  6850 permits the definition of tail-recursive functions without the
  6851 provision of a termination measure. The latter is necessary once the
  6852 invariant proof rule for while is applied.
  6853 
  6854 * HOL: new (overloaded) notation for the set of elements below/above
  6855 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6856 
  6857 * HOL: theorems impI, allI, ballI bound as "strip";
  6858 
  6859 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6860 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6861 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6862 
  6863 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6864 
  6865 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6866 main HOL, but was unused);
  6867 
  6868 * HOL: fewer consts declared as global (e.g. have to refer to
  6869 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6870 
  6871 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6872 in case of overlap with user translations (e.g. judgements over
  6873 tuples); (note that the underlying logical represenation is still
  6874 bogus);
  6875 
  6876 
  6877 *** ZF ***
  6878 
  6879 * ZF: simplification automatically cancels common terms in arithmetic
  6880 expressions over nat and int;
  6881 
  6882 * ZF: new treatment of nat to minimize type-checking: all operators
  6883 coerce their operands to a natural number using the function natify,
  6884 making the algebraic laws unconditional;
  6885 
  6886 * ZF: as above, for int: operators coerce their operands to an integer
  6887 using the function intify;
  6888 
  6889 * ZF: the integer library now contains many of the usual laws for the
  6890 orderings, including $<=, and monotonicity laws for $+ and $*;
  6891 
  6892 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  6893 simplification;
  6894 
  6895 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  6896 to the simplifier and classical reasoner simultaneously;
  6897 
  6898 
  6899 *** General ***
  6900 
  6901 * Provers: blast_tac now handles actual object-logic rules as
  6902 assumptions; note that auto_tac uses blast_tac internally as well;
  6903 
  6904 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  6905 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  6906 
  6907 * Provers: delrules now handles destruct rules as well (no longer need
  6908 explicit make_elim);
  6909 
  6910 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  6911   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6912 use instead the strong form,
  6913   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6914 in HOL, FOL and ZF the function cla_make_elim will create such rules
  6915 from destruct-rules;
  6916 
  6917 * Provers: Simplifier.easy_setup provides a fast path to basic
  6918 Simplifier setup for new object-logics;
  6919 
  6920 * Pure: AST translation rules no longer require constant head on LHS;
  6921 
  6922 * Pure: improved name spaces: ambiguous output is qualified; support
  6923 for hiding of names;
  6924 
  6925 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  6926 XSYMBOL_HOME; no longer need to do manual configuration in most
  6927 situations;
  6928 
  6929 * system: compression of ML heaps images may now be controlled via -c
  6930 option of isabelle and isatool usedir (currently only observed by
  6931 Poly/ML);
  6932 
  6933 * system: isatool installfonts may handle X-Symbol fonts as well (very
  6934 useful for remote X11);
  6935 
  6936 * system: provide TAGS file for Isabelle sources;
  6937 
  6938 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  6939 order;
  6940 
  6941 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  6942 timing flag supersedes proof_timing and Toplevel.trace;
  6943 
  6944 * ML: new combinators |>> and |>>> for incremental transformations
  6945 with secondary results (e.g. certain theory extensions):
  6946 
  6947 * ML: PureThy.add_defs gets additional argument to indicate potential
  6948 overloading (usually false);
  6949 
  6950 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  6951 results;
  6952 
  6953 
  6954 
  6955 New in Isabelle99 (October 1999)
  6956 --------------------------------
  6957 
  6958 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6959 
  6960 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  6961 are no longer simplified.  (This allows the simplifier to unfold recursive
  6962 functional programs.)  To restore the old behaviour, declare
  6963 
  6964     Delcongs [if_weak_cong];
  6965 
  6966 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  6967 complement;
  6968 
  6969 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  6970 
  6971 * HOL/datatype: mutual_induct_tac no longer exists --
  6972   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  6973 
  6974 * HOL/typedef: fixed type inference for representing set; type
  6975 arguments now have to occur explicitly on the rhs as type constraints;
  6976 
  6977 * ZF: The con_defs part of an inductive definition may no longer refer
  6978 to constants declared in the same theory;
  6979 
  6980 * HOL, ZF: the function mk_cases, generated by the inductive
  6981 definition package, has lost an argument.  To simplify its result, it
  6982 uses the default simpset instead of a supplied list of theorems.
  6983 
  6984 * HOL/List: the constructors of type list are now Nil and Cons;
  6985 
  6986 * Simplifier: the type of the infix ML functions
  6987         setSSolver addSSolver setSolver addSolver
  6988 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  6989 for packaging solvers. A solver is created via
  6990         mk_solver: string -> (thm list -> int -> tactic) -> solver
  6991 where the string argument is only a comment.
  6992 
  6993 
  6994 *** Proof tools ***
  6995 
  6996 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  6997 decision procedure for linear arithmetic. Currently it is used for
  6998 types `nat', `int', and `real' in HOL (see below); it can, should and
  6999 will be instantiated for other types and logics as well.
  7000 
  7001 * The simplifier now accepts rewrite rules with flexible heads, eg
  7002      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  7003   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  7004   matching.
  7005 
  7006 
  7007 *** General ***
  7008 
  7009 * New Isabelle/Isar subsystem provides an alternative to traditional
  7010 tactical theorem proving; together with the ProofGeneral/isar user
  7011 interface it offers an interactive environment for developing human
  7012 readable proof documents (Isar == Intelligible semi-automated
  7013 reasoning); for further information see isatool doc isar-ref,
  7014 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  7015 
  7016 * improved and simplified presentation of theories: better HTML markup
  7017 (including colors), graph views in several sizes; isatool usedir now
  7018 provides a proper interface for user theories (via -P option); actual
  7019 document preparation based on (PDF)LaTeX is available as well (for
  7020 new-style theories only); see isatool doc system for more information;
  7021 
  7022 * native support for Proof General, both for classic Isabelle and
  7023 Isabelle/Isar;
  7024 
  7025 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  7026 using the graph browser tool;
  7027 
  7028 * Isabelle manuals now also available as PDF;
  7029 
  7030 * theory loader rewritten from scratch (may not be fully
  7031 bug-compatible); old loadpath variable has been replaced by show_path,
  7032 add_path, del_path, reset_path functions; new operations such as
  7033 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  7034 isatool doc ref);
  7035 
  7036 * improved isatool install: option -k creates KDE application icon,
  7037 option -p DIR installs standalone binaries;
  7038 
  7039 * added ML_PLATFORM setting (useful for cross-platform installations);
  7040 more robust handling of platform specific ML images for SML/NJ;
  7041 
  7042 * the settings environment is now statically scoped, i.e. it is never
  7043 created again in sub-processes invoked from isabelle, isatool, or
  7044 Isabelle;
  7045 
  7046 * path element specification '~~' refers to '$ISABELLE_HOME';
  7047 
  7048 * in locales, the "assumes" and "defines" parts may be omitted if
  7049 empty;
  7050 
  7051 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  7052 long arrows);
  7053 
  7054 * new print_mode "HTML";
  7055 
  7056 * new flag show_tags controls display of tags of theorems (which are
  7057 basically just comments that may be attached by some tools);
  7058 
  7059 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  7060 mode and goal output format:
  7061 
  7062 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  7063 244c244
  7064 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  7065 ---
  7066 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  7067 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  7068 181c181
  7069 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  7070 ---
  7071 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  7072 
  7073 * function bind_thms stores lists of theorems (cf. bind_thm);
  7074 
  7075 * new shorthand tactics ftac, eatac, datac, fatac;
  7076 
  7077 * qed (and friends) now accept "" as result name; in that case the
  7078 theorem is not stored, but proper checks and presentation of the
  7079 result still apply;
  7080 
  7081 * theorem database now also indexes constants "Trueprop", "all",
  7082 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  7083 
  7084 
  7085 *** HOL ***
  7086 
  7087 ** HOL arithmetic **
  7088 
  7089 * There are now decision procedures for linear arithmetic over nat and
  7090 int:
  7091 
  7092 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  7093 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  7094 are treated as atomic; subformulae not involving type `nat' or `int'
  7095 are ignored; quantified subformulae are ignored unless they are
  7096 positive universal or negative existential. The tactic has to be
  7097 invoked by hand and can be a little bit slow. In particular, the
  7098 running time is exponential in the number of occurrences of `min' and
  7099 `max', and `-' on `nat'.
  7100 
  7101 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  7102 (negated) (in)equalities among the premises and the conclusion into
  7103 account (i.e. no compound formulae) and does not know about `min' and
  7104 `max', and `-' on `nat'. It is fast and is used automatically by the
  7105 simplifier.
  7106 
  7107 NB: At the moment, these decision procedures do not cope with mixed
  7108 nat/int formulae where the two parts interact, such as `m < n ==>
  7109 int(m) < int(n)'.
  7110 
  7111 * HOL/Numeral provides a generic theory of numerals (encoded
  7112 efficiently as bit strings); setup for types nat/int/real is in place;
  7113 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  7114 int, existing theories and proof scripts may require a few additional
  7115 type constraints;
  7116 
  7117 * integer division and remainder can now be performed on constant
  7118 arguments;
  7119 
  7120 * many properties of integer multiplication, division and remainder
  7121 are now available;
  7122 
  7123 * An interface to the Stanford Validity Checker (SVC) is available through the
  7124 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  7125 are proved automatically.  SVC must be installed separately, and its results
  7126 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  7127 invocation of the underlying oracle).  For SVC see
  7128   http://verify.stanford.edu/SVC
  7129 
  7130 * IsaMakefile: the HOL-Real target now builds an actual image;
  7131 
  7132 
  7133 ** HOL misc **
  7134 
  7135 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  7136 (in Isabelle/Isar) -- by Gertrud Bauer;
  7137 
  7138 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  7139 analysis for assembly languages with subtypes;
  7140 
  7141 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  7142 -- avoids syntactic ambiguities and treats state, transition, and
  7143 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  7144 changed syntax and (many) tactics;
  7145 
  7146 * HOL/inductive: Now also handles more general introduction rules such
  7147   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  7148   theorems are now maintained within the theory (maintained via the
  7149   "mono" attribute);
  7150 
  7151 * HOL/datatype: Now also handles arbitrarily branching datatypes
  7152   (using function types) such as
  7153 
  7154   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  7155 
  7156 * HOL/record: record_simproc (part of the default simpset) takes care
  7157 of selectors applied to updated records; record_split_tac is no longer
  7158 part of the default claset; update_defs may now be removed from the
  7159 simpset in many cases; COMPATIBILITY: old behavior achieved by
  7160 
  7161   claset_ref () := claset() addSWrapper record_split_wrapper;
  7162   Delsimprocs [record_simproc]
  7163 
  7164 * HOL/typedef: fixed type inference for representing set; type
  7165 arguments now have to occur explicitly on the rhs as type constraints;
  7166 
  7167 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  7168 names rather than an ML expression;
  7169 
  7170 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  7171 supplied later.  Program schemes can be defined, such as
  7172     "While B C s = (if B s then While B C (C s) else s)"
  7173 where the well-founded relation can be chosen after B and C have been given.
  7174 
  7175 * HOL/List: the constructors of type list are now Nil and Cons;
  7176 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  7177 course, ML tools referring to List.list.op # etc. have to be adapted;
  7178 
  7179 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  7180 disabled by default; run isabelle with option -m HOL to get back to
  7181 the original Gordon/HOL-style output;
  7182 
  7183 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  7184 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  7185 
  7186 * HOL basic syntax simplified (more orthogonal): all variants of
  7187 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  7188 Eps operator is provided as well: "SOME x. P[x]";
  7189 
  7190 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  7191 
  7192 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  7193 thus available for user theories;
  7194 
  7195 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  7196 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  7197 time;
  7198 
  7199 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  7200 several times and then mp;
  7201 
  7202 
  7203 *** LK ***
  7204 
  7205 * the notation <<...>> is now available as a notation for sequences of
  7206 formulas;
  7207 
  7208 * the simplifier is now installed
  7209 
  7210 * the axiom system has been generalized (thanks to Soren Heilmann)
  7211 
  7212 * the classical reasoner now has a default rule database
  7213 
  7214 
  7215 *** ZF ***
  7216 
  7217 * new primrec section allows primitive recursive functions to be given
  7218 directly (as in HOL) over datatypes and the natural numbers;
  7219 
  7220 * new tactics induct_tac and exhaust_tac for induction (or case
  7221 analysis) over datatypes and the natural numbers;
  7222 
  7223 * the datatype declaration of type T now defines the recursor T_rec;
  7224 
  7225 * simplification automatically does freeness reasoning for datatype
  7226 constructors;
  7227 
  7228 * automatic type-inference, with AddTCs command to insert new
  7229 type-checking rules;
  7230 
  7231 * datatype introduction rules are now added as Safe Introduction rules
  7232 to the claset;
  7233 
  7234 * the syntax "if P then x else y" is now available in addition to
  7235 if(P,x,y);
  7236 
  7237 
  7238 *** Internal programming interfaces ***
  7239 
  7240 * tuned simplifier trace output; new flag debug_simp;
  7241 
  7242 * structures Vartab / Termtab (instances of TableFun) offer efficient
  7243 tables indexed by indexname_ord / term_ord (compatible with aconv);
  7244 
  7245 * AxClass.axclass_tac lost the theory argument;
  7246 
  7247 * tuned current_goals_markers semantics: begin / end goal avoids
  7248 printing empty lines;
  7249 
  7250 * removed prs and prs_fn hook, which was broken because it did not
  7251 include \n in its semantics, forcing writeln to add one
  7252 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  7253 string -> unit if you really want to output text without newline;
  7254 
  7255 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  7256 plain output, interface builders may have to enable 'isabelle_font'
  7257 mode to get Isabelle font glyphs as before;
  7258 
  7259 * refined token_translation interface; INCOMPATIBILITY: output length
  7260 now of type real instead of int;
  7261 
  7262 * theory loader actions may be traced via new ThyInfo.add_hook
  7263 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  7264 your own database of information attached to *whole* theories -- as
  7265 opposed to intra-theory data slots offered via TheoryDataFun;
  7266 
  7267 * proper handling of dangling sort hypotheses (at last!);
  7268 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  7269 extra sort hypotheses that can be witnessed from the type signature;
  7270 the force_strip_shyps flag is gone, any remaining shyps are simply
  7271 left in the theorem (with a warning issued by strip_shyps_warning);
  7272 
  7273 
  7274 
  7275 New in Isabelle98-1 (October 1998)
  7276 ----------------------------------
  7277 
  7278 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7279 
  7280 * several changes of automated proof tools;
  7281 
  7282 * HOL: major changes to the inductive and datatype packages, including
  7283 some minor incompatibilities of theory syntax;
  7284 
  7285 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  7286 called `inj_on';
  7287 
  7288 * HOL: removed duplicate thms in Arith:
  7289   less_imp_add_less  should be replaced by  trans_less_add1
  7290   le_imp_add_le      should be replaced by  trans_le_add1
  7291 
  7292 * HOL: unary minus is now overloaded (new type constraints may be
  7293 required);
  7294 
  7295 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  7296 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  7297 now taken as an integer constant.
  7298 
  7299 * Pure: ML function 'theory_of' renamed to 'theory';
  7300 
  7301 
  7302 *** Proof tools ***
  7303 
  7304 * Simplifier:
  7305   1. Asm_full_simp_tac is now more aggressive.
  7306      1. It will sometimes reorient premises if that increases their power to
  7307         simplify.
  7308      2. It does no longer proceed strictly from left to right but may also
  7309         rotate premises to achieve further simplification.
  7310      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  7311      old Asm_full_simp_tac in that it does not rotate premises.
  7312   2. The simplifier now knows a little bit about nat-arithmetic.
  7313 
  7314 * Classical reasoner: wrapper mechanism for the classical reasoner now
  7315 allows for selected deletion of wrappers, by introduction of names for
  7316 wrapper functionals.  This implies that addbefore, addSbefore,
  7317 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  7318 and that adding two tactics with the same name overwrites the first
  7319 one (emitting a warning).
  7320   type wrapper = (int -> tactic) -> (int -> tactic)
  7321   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  7322   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  7323   delWrapper, delSWrapper: claset *  string            -> claset
  7324   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  7325 
  7326 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  7327 semantics; addbefore now affects only the unsafe part of step_tac
  7328 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  7329 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  7330 by Force_tac;
  7331 
  7332 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  7333 compWrapper; added safe wrapper (and access functions for it);
  7334 
  7335 * HOL/split_all_tac is now much faster and fails if there is nothing
  7336 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  7337 and the names of the automatically generated variables have changed.
  7338 split_all_tac has moved within claset() from unsafe wrappers to safe
  7339 wrappers, which means that !!-bound variables are split much more
  7340 aggressively, and safe_tac and clarify_tac now split such variables.
  7341 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  7342 Note: the same holds for record_split_tac, which does the job of
  7343 split_all_tac for record fields.
  7344 
  7345 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  7346 permanently to the default simpset using Addsplits just like
  7347 Addsimps. They can be removed via Delsplits just like
  7348 Delsimps. Lower-case versions are also available.
  7349 
  7350 * HOL/Simplifier: The rule split_if is now part of the default
  7351 simpset. This means that the simplifier will eliminate all occurrences
  7352 of if-then-else in the conclusion of a goal. To prevent this, you can
  7353 either remove split_if completely from the default simpset by
  7354 `Delsplits [split_if]' or remove it in a specific call of the
  7355 simplifier using `... delsplits [split_if]'.  You can also add/delete
  7356 other case splitting rules to/from the default simpset: every datatype
  7357 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  7358 t is the name of the datatype).
  7359 
  7360 * Classical reasoner / Simplifier combination: new force_tac (and
  7361 derivatives Force_tac, force) combines rewriting and classical
  7362 reasoning (and whatever other tools) similarly to auto_tac, but is
  7363 aimed to solve the given subgoal completely.
  7364 
  7365 
  7366 *** General ***
  7367 
  7368 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  7369 and `goalw': the theory is no longer needed as an explicit argument -
  7370 the current theory context is used; assumptions are no longer returned
  7371 at the ML-level unless one of them starts with ==> or !!; it is
  7372 recommended to convert to these new commands using isatool fixgoal
  7373 (backup your sources first!);
  7374 
  7375 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  7376 the current theory context, and 'theory' to lookup stored theories;
  7377 
  7378 * new theory section 'locale' for declaring constants, assumptions and
  7379 definitions that have local scope;
  7380 
  7381 * new theory section 'nonterminals' for purely syntactic types;
  7382 
  7383 * new theory section 'setup' for generic ML setup functions
  7384 (e.g. package initialization);
  7385 
  7386 * the distribution now includes Isabelle icons: see
  7387 lib/logo/isabelle-{small,tiny}.xpm;
  7388 
  7389 * isatool install - install binaries with absolute references to
  7390 ISABELLE_HOME/bin;
  7391 
  7392 * isatool logo -- create instances of the Isabelle logo (as EPS);
  7393 
  7394 * print mode 'emacs' reserved for Isamode;
  7395 
  7396 * support multiple print (ast) translations per constant name;
  7397 
  7398 * theorems involving oracles are now printed with a suffixed [!];
  7399 
  7400 
  7401 *** HOL ***
  7402 
  7403 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  7404 
  7405 * HOL/inductive package reorganized and improved: now supports mutual
  7406 definitions such as
  7407 
  7408   inductive EVEN ODD
  7409     intrs
  7410       null "0 : EVEN"
  7411       oddI "n : EVEN ==> Suc n : ODD"
  7412       evenI "n : ODD ==> Suc n : EVEN"
  7413 
  7414 new theorem list "elims" contains an elimination rule for each of the
  7415 recursive sets; inductive definitions now handle disjunctive premises
  7416 correctly (also ZF);
  7417 
  7418 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  7419 "mutual_induct" no longer exists - the induction rule is always
  7420 contained in "induct";
  7421 
  7422 
  7423 * HOL/datatype package re-implemented and greatly improved: now
  7424 supports mutually recursive datatypes such as
  7425 
  7426   datatype
  7427     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  7428             | SUM ('a aexp) ('a aexp)
  7429             | DIFF ('a aexp) ('a aexp)
  7430             | NUM 'a
  7431   and
  7432     'a bexp = LESS ('a aexp) ('a aexp)
  7433             | AND ('a bexp) ('a bexp)
  7434             | OR ('a bexp) ('a bexp)
  7435 
  7436 as well as indirectly recursive datatypes such as
  7437 
  7438   datatype
  7439     ('a, 'b) term = Var 'a
  7440                   | App 'b ((('a, 'b) term) list)
  7441 
  7442 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  7443 induction on mutually / indirectly recursive datatypes.
  7444 
  7445 Primrec equations are now stored in theory and can be accessed via
  7446 <function_name>.simps.
  7447 
  7448 INCOMPATIBILITIES:
  7449 
  7450   - Theories using datatypes must now have theory Datatype as an
  7451     ancestor.
  7452   - The specific <typename>.induct_tac no longer exists - use the
  7453     generic induct_tac instead.
  7454   - natE has been renamed to nat.exhaust - use exhaust_tac
  7455     instead of res_inst_tac ... natE. Note that the variable
  7456     names in nat.exhaust differ from the names in natE, this
  7457     may cause some "fragile" proofs to fail.
  7458   - The theorems split_<typename>_case and split_<typename>_case_asm
  7459     have been renamed to <typename>.split and <typename>.split_asm.
  7460   - Since default sorts of type variables are now handled correctly,
  7461     some datatype definitions may have to be annotated with explicit
  7462     sort constraints.
  7463   - Primrec definitions no longer require function name and type
  7464     of recursive argument.
  7465 
  7466 Consider using isatool fixdatatype to adapt your theories and proof
  7467 scripts to the new package (backup your sources first!).
  7468 
  7469 
  7470 * HOL/record package: considerably improved implementation; now
  7471 includes concrete syntax for record types, terms, updates; theorems
  7472 for surjective pairing and splitting !!-bound record variables; proof
  7473 support is as follows:
  7474 
  7475   1) standard conversions (selectors or updates applied to record
  7476 constructor terms) are part of the standard simpset;
  7477 
  7478   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  7479 made part of standard simpset and claset via addIffs;
  7480 
  7481   3) a tactic for record field splitting (record_split_tac) is part of
  7482 the standard claset (addSWrapper);
  7483 
  7484 To get a better idea about these rules you may retrieve them via
  7485 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  7486 the name of your record type.
  7487 
  7488 The split tactic 3) conceptually simplifies by the following rule:
  7489 
  7490   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  7491 
  7492 Thus any record variable that is bound by meta-all will automatically
  7493 blow up into some record constructor term, consequently the
  7494 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  7495 solve record problems automatically.
  7496 
  7497 
  7498 * reorganized the main HOL image: HOL/Integ and String loaded by
  7499 default; theory Main includes everything;
  7500 
  7501 * automatic simplification of integer sums and comparisons, using cancellation;
  7502 
  7503 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  7504 
  7505 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  7506 
  7507 * many new identities for unions, intersections, set difference, etc.;
  7508 
  7509 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  7510 called split_if, split_split, split_sum_case and split_nat_case (to go
  7511 with add/delsplits);
  7512 
  7513 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  7514 (?x::unit) = (); this is made part of the default simpset, which COULD
  7515 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  7516 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  7517 unit_abs_eta_conv is added in order to counter the effect of
  7518 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  7519 %u.f();
  7520 
  7521 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  7522 makes more sense);
  7523 
  7524 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7525   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7526   disjointness reasoning but breaking a few old proofs.
  7527 
  7528 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  7529 to 'converse' from 'inverse' (for compatibility with ZF and some
  7530 literature);
  7531 
  7532 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  7533 the well-founded relation;
  7534 
  7535 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  7536     Compl A.  The "Compl" syntax remains available as input syntax for this
  7537     release ONLY.
  7538 
  7539 * HOL/Update: new theory of function updates:
  7540     f(a:=b) == %x. if x=a then b else f x
  7541 may also be iterated as in f(a:=b,c:=d,...);
  7542 
  7543 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  7544 
  7545 * HOL/List:
  7546   - new function list_update written xs[i:=v] that updates the i-th
  7547     list position. May also be iterated as in xs[i:=a,j:=b,...].
  7548   - new function `upt' written [i..j(] which generates the list
  7549     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  7550     bound write [i..j], which is a shorthand for [i..j+1(].
  7551   - new lexicographic orderings and corresponding wellfoundedness theorems.
  7552 
  7553 * HOL/Arith:
  7554   - removed 'pred' (predecessor) function;
  7555   - generalized some theorems about n-1;
  7556   - many new laws about "div" and "mod";
  7557   - new laws about greatest common divisors (see theory ex/Primes);
  7558 
  7559 * HOL/Relation: renamed the relational operator r^-1 "converse"
  7560 instead of "inverse";
  7561 
  7562 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  7563   of the multiset ordering;
  7564 
  7565 * directory HOL/Real: a construction of the reals using Dedekind cuts
  7566   (not included by default);
  7567 
  7568 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  7569 
  7570 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  7571   programs, i.e. different program variables may have different types.
  7572 
  7573 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7574   [previously, this check worked only if the rewrite rule was unconditional]
  7575   Now rew can involve either definitions or equalities (either == or =).
  7576 
  7577 
  7578 *** ZF ***
  7579 
  7580 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  7581   only the theorems proved on ZF.ML;
  7582 
  7583 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7584   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7585   disjointness reasoning but breaking a few old proofs.
  7586 
  7587 * ZF/Update: new theory of function updates
  7588     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  7589   may also be iterated as in f(a:=b,c:=d,...);
  7590 
  7591 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  7592 
  7593 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7594   [previously, this check worked only if the rewrite rule was unconditional]
  7595   Now rew can involve either definitions or equalities (either == or =).
  7596 
  7597 * case_tac provided for compatibility with HOL
  7598     (like the old excluded_middle_tac, but with subgoals swapped)
  7599 
  7600 
  7601 *** Internal programming interfaces ***
  7602 
  7603 * Pure: several new basic modules made available for general use, see
  7604 also src/Pure/README;
  7605 
  7606 * improved the theory data mechanism to support encapsulation (data
  7607 kind name replaced by private Object.kind, acting as authorization
  7608 key); new type-safe user interface via functor TheoryDataFun; generic
  7609 print_data function becomes basically useless;
  7610 
  7611 * removed global_names compatibility flag -- all theory declarations
  7612 are qualified by default;
  7613 
  7614 * module Pure/Syntax now offers quote / antiquote translation
  7615 functions (useful for Hoare logic etc. with implicit dependencies);
  7616 see HOL/ex/Antiquote for an example use;
  7617 
  7618 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  7619 cterm -> thm;
  7620 
  7621 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  7622 subgoal;
  7623 
  7624 * Display.print_goals function moved to Locale.print_goals;
  7625 
  7626 * standard print function for goals supports current_goals_markers
  7627 variable for marking begin of proof, end of proof, start of goal; the
  7628 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  7629 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  7630 for example;
  7631 
  7632 
  7633 
  7634 New in Isabelle98 (January 1998)
  7635 --------------------------------
  7636 
  7637 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7638 
  7639 * changed lexical syntax of terms / types: dots made part of long
  7640 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  7641 
  7642 * simpset (and claset) reference variable replaced by functions
  7643 simpset / simpset_ref;
  7644 
  7645 * no longer supports theory aliases (via merge) and non-trivial
  7646 implicit merge of thms' signatures;
  7647 
  7648 * most internal names of constants changed due to qualified names;
  7649 
  7650 * changed Pure/Sequence interface (see Pure/seq.ML);
  7651 
  7652 
  7653 *** General Changes ***
  7654 
  7655 * hierachically structured name spaces (for consts, types, axms, thms
  7656 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  7657 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  7658 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  7659 long_names for fully qualified output names; NOTE: ML programs
  7660 (special tactics, packages etc.) referring to internal names may have
  7661 to be adapted to cope with fully qualified names; in case of severe
  7662 backward campatibility problems try setting 'global_names' at compile
  7663 time to have enrything declared within a flat name space; one may also
  7664 fine tune name declarations in theories via the 'global' and 'local'
  7665 section;
  7666 
  7667 * reimplemented the implicit simpset and claset using the new anytype
  7668 data filed in signatures; references simpset:simpset ref etc. are
  7669 replaced by functions simpset:unit->simpset and
  7670 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  7671 to patch your ML files accordingly;
  7672 
  7673 * HTML output now includes theory graph data for display with Java
  7674 applet or isatool browser; data generated automatically via isatool
  7675 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  7676 
  7677 * defs may now be conditional; improved rewrite_goals_tac to handle
  7678 conditional equations;
  7679 
  7680 * defs now admits additional type arguments, using TYPE('a) syntax;
  7681 
  7682 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  7683 creates a new theory node; implicit merge of thms' signatures is
  7684 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  7685 transfer:theory->thm->thm in (rare) cases;
  7686 
  7687 * improved handling of draft signatures / theories; draft thms (and
  7688 ctyps, cterms) are automatically promoted to real ones;
  7689 
  7690 * slightly changed interfaces for oracles: admit many per theory, named
  7691 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  7692 
  7693 * print_goals: optional output of const types (set show_consts and
  7694 show_types);
  7695 
  7696 * improved output of warnings (###) and errors (***);
  7697 
  7698 * subgoal_tac displays a warning if the new subgoal has type variables;
  7699 
  7700 * removed old README and Makefiles;
  7701 
  7702 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  7703 
  7704 * removed obsolete init_pps and init_database;
  7705 
  7706 * deleted the obsolete tactical STATE, which was declared by
  7707     fun STATE tacfun st = tacfun st st;
  7708 
  7709 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  7710 (which abbreviates $HOME);
  7711 
  7712 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  7713 use isatool fixseq to adapt your ML programs (this works for fully
  7714 qualified references to the Sequence structure only!);
  7715 
  7716 * use_thy no longer requires writable current directory; it always
  7717 reloads .ML *and* .thy file, if either one is out of date;
  7718 
  7719 
  7720 *** Classical Reasoner ***
  7721 
  7722 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  7723 tactics that use classical reasoning to simplify a subgoal without
  7724 splitting it into several subgoals;
  7725 
  7726 * Safe_tac: like safe_tac but uses the default claset;
  7727 
  7728 
  7729 *** Simplifier ***
  7730 
  7731 * added simplification meta rules:
  7732     (asm_)(full_)simplify: simpset -> thm -> thm;
  7733 
  7734 * simplifier.ML no longer part of Pure -- has to be loaded by object
  7735 logics (again);
  7736 
  7737 * added prems argument to simplification procedures;
  7738 
  7739 * HOL, FOL, ZF: added infix function `addsplits':
  7740   instead of `<simpset> setloop (split_tac <thms>)'
  7741   you can simply write `<simpset> addsplits <thms>'
  7742 
  7743 
  7744 *** Syntax ***
  7745 
  7746 * TYPE('a) syntax for type reflection terms;
  7747 
  7748 * no longer handles consts with name "" -- declare as 'syntax' instead;
  7749 
  7750 * pretty printer: changed order of mixfix annotation preference (again!);
  7751 
  7752 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  7753 
  7754 
  7755 *** HOL ***
  7756 
  7757 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7758   with `addloop' of the simplifier to faciliate case splitting in premises.
  7759 
  7760 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  7761 
  7762 * HOL/Auth: new protocol proofs including some for the Internet
  7763   protocol TLS;
  7764 
  7765 * HOL/Map: new theory of `maps' a la VDM;
  7766 
  7767 * HOL/simplifier: simplification procedures nat_cancel_sums for
  7768 cancelling out common nat summands from =, <, <= (in)equalities, or
  7769 differences; simplification procedures nat_cancel_factor for
  7770 cancelling common factor from =, <, <= (in)equalities over natural
  7771 sums; nat_cancel contains both kinds of procedures, it is installed by
  7772 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  7773 
  7774 * HOL/simplifier: terms of the form
  7775   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  7776   are rewritten to
  7777   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  7778   and those of the form
  7779   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  7780   are rewritten to
  7781   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  7782 
  7783 * HOL/datatype
  7784   Each datatype `t' now comes with a theorem `split_t_case' of the form
  7785 
  7786   P(t_case f1 ... fn x) =
  7787      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  7788         ...
  7789        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  7790      )
  7791 
  7792   and a theorem `split_t_case_asm' of the form
  7793 
  7794   P(t_case f1 ... fn x) =
  7795     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  7796         ...
  7797        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  7798      )
  7799   which can be added to a simpset via `addsplits'. The existing theorems
  7800   expand_list_case and expand_option_case have been renamed to
  7801   split_list_case and split_option_case.
  7802 
  7803 * HOL/Arithmetic:
  7804   - `pred n' is automatically converted to `n-1'.
  7805     Users are strongly encouraged not to use `pred' any longer,
  7806     because it will disappear altogether at some point.
  7807   - Users are strongly encouraged to write "0 < n" rather than
  7808     "n ~= 0". Theorems and proof tools have been modified towards this
  7809     `standard'.
  7810 
  7811 * HOL/Lists:
  7812   the function "set_of_list" has been renamed "set" (and its theorems too);
  7813   the function "nth" now takes its arguments in the reverse order and
  7814   has acquired the infix notation "!" as in "xs!n".
  7815 
  7816 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  7817 
  7818 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  7819   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  7820 
  7821 * HOL/record: extensible records with schematic structural subtyping
  7822 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  7823 still lacks various theorems and concrete record syntax;
  7824 
  7825 
  7826 *** HOLCF ***
  7827 
  7828 * removed "axioms" and "generated by" sections;
  7829 
  7830 * replaced "ops" section by extended "consts" section, which is capable of
  7831   handling the continuous function space "->" directly;
  7832 
  7833 * domain package:
  7834   . proves theorems immediately and stores them in the theory,
  7835   . creates hierachical name space,
  7836   . now uses normal mixfix annotations (instead of cinfix...),
  7837   . minor changes to some names and values (for consistency),
  7838   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  7839   . separator between mutual domain defs: changed "," to "and",
  7840   . improved handling of sort constraints;  now they have to
  7841     appear on the left-hand side of the equations only;
  7842 
  7843 * fixed LAM <x,y,zs>.b syntax;
  7844 
  7845 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  7846 adm (%x. P (t x)), where P is chainfinite and t continuous;
  7847 
  7848 
  7849 *** FOL and ZF ***
  7850 
  7851 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7852   with `addloop' of the simplifier to faciliate case splitting in premises.
  7853 
  7854 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  7855 in HOL, they strip ALL and --> from proved theorems;
  7856 
  7857 
  7858 
  7859 New in Isabelle94-8 (May 1997)
  7860 ------------------------------
  7861 
  7862 *** General Changes ***
  7863 
  7864 * new utilities to build / run / maintain Isabelle etc. (in parts
  7865 still somewhat experimental); old Makefiles etc. still functional;
  7866 
  7867 * new 'Isabelle System Manual';
  7868 
  7869 * INSTALL text, together with ./configure and ./build scripts;
  7870 
  7871 * reimplemented type inference for greater efficiency, better error
  7872 messages and clean internal interface;
  7873 
  7874 * prlim command for dealing with lots of subgoals (an easier way of
  7875 setting goals_limit);
  7876 
  7877 
  7878 *** Syntax ***
  7879 
  7880 * supports alternative (named) syntax tables (parser and pretty
  7881 printer); internal interface is provided by add_modesyntax(_i);
  7882 
  7883 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  7884 be used in conjunction with the Isabelle symbol font; uses the
  7885 "symbols" syntax table;
  7886 
  7887 * added token_translation interface (may translate name tokens in
  7888 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  7889 the current print_mode); IMPORTANT: user print translation functions
  7890 are responsible for marking newly introduced bounds
  7891 (Syntax.mark_boundT);
  7892 
  7893 * token translations for modes "xterm" and "xterm_color" that display
  7894 names in bold, underline etc. or colors (which requires a color
  7895 version of xterm);
  7896 
  7897 * infixes may now be declared with names independent of their syntax;
  7898 
  7899 * added typed_print_translation (like print_translation, but may
  7900 access type of constant);
  7901 
  7902 
  7903 *** Classical Reasoner ***
  7904 
  7905 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  7906 some limitations.  Blast_tac...
  7907   + ignores addss, addbefore, addafter; this restriction is intrinsic
  7908   + ignores elimination rules that don't have the correct format
  7909         (the conclusion MUST be a formula variable)
  7910   + ignores types, which can make HOL proofs fail
  7911   + rules must not require higher-order unification, e.g. apply_type in ZF
  7912     [message "Function Var's argument not a bound variable" relates to this]
  7913   + its proof strategy is more general but can actually be slower
  7914 
  7915 * substitution with equality assumptions no longer permutes other
  7916 assumptions;
  7917 
  7918 * minor changes in semantics of addafter (now called addaltern); renamed
  7919 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  7920 (and access functions for it);
  7921 
  7922 * improved combination of classical reasoner and simplifier:
  7923   + functions for handling clasimpsets
  7924   + improvement of addss: now the simplifier is called _after_ the
  7925     safe steps.
  7926   + safe variant of addss called addSss: uses safe simplifications
  7927     _during_ the safe steps. It is more complete as it allows multiple
  7928     instantiations of unknowns (e.g. with slow_tac).
  7929 
  7930 *** Simplifier ***
  7931 
  7932 * added interface for simplification procedures (functions that
  7933 produce *proven* rewrite rules on the fly, depending on current
  7934 redex);
  7935 
  7936 * ordering on terms as parameter (used for ordered rewriting);
  7937 
  7938 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  7939 
  7940 * the solver is now split into a safe and an unsafe part.
  7941 This should be invisible for the normal user, except that the
  7942 functions setsolver and addsolver have been renamed to setSolver and
  7943 addSolver; added safe_asm_full_simp_tac;
  7944 
  7945 
  7946 *** HOL ***
  7947 
  7948 * a generic induction tactic `induct_tac' which works for all datatypes and
  7949 also for type `nat';
  7950 
  7951 * a generic case distinction tactic `exhaust_tac' which works for all
  7952 datatypes and also for type `nat';
  7953 
  7954 * each datatype comes with a function `size';
  7955 
  7956 * patterns in case expressions allow tuple patterns as arguments to
  7957 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  7958 
  7959 * primrec now also works with type nat;
  7960 
  7961 * recdef: a new declaration form, allows general recursive functions to be
  7962 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  7963 
  7964 * the constant for negation has been renamed from "not" to "Not" to
  7965 harmonize with FOL, ZF, LK, etc.;
  7966 
  7967 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  7968 infinite lists;
  7969 
  7970 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  7971 
  7972 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  7973 problems in commutative rings, using axiomatic type classes for + and *;
  7974 
  7975 * more examples in HOL/MiniML and HOL/Auth;
  7976 
  7977 * more default rewrite rules for quantifiers, union/intersection;
  7978 
  7979 * a new constant `arbitrary == @x.False';
  7980 
  7981 * HOLCF/IOA replaces old HOL/IOA;
  7982 
  7983 * HOLCF changes: derived all rules and arities
  7984   + axiomatic type classes instead of classes
  7985   + typedef instead of faking type definitions
  7986   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  7987   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  7988   + eliminated the types void, one, tr
  7989   + use unit lift and bool lift (with translations) instead of one and tr
  7990   + eliminated blift from Lift3.thy (use Def instead of blift)
  7991   all eliminated rules are derived as theorems --> no visible changes ;
  7992 
  7993 
  7994 *** ZF ***
  7995 
  7996 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  7997 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  7998 as ZF_cs addSIs [equalityI];
  7999 
  8000 
  8001 
  8002 New in Isabelle94-7 (November 96)
  8003 ---------------------------------
  8004 
  8005 * allowing negative levels (as offsets) in prlev and choplev;
  8006 
  8007 * super-linear speedup for large simplifications;
  8008 
  8009 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  8010 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  8011 FAIL); can suppress it using the command Delsimps (ex_simps @
  8012 all_simps); De Morgan laws are also now included, by default;
  8013 
  8014 * improved printing of ==>  :  ~:
  8015 
  8016 * new object-logic "Sequents" adds linear logic, while replacing LK
  8017 and Modal (thanks to Sara Kalvala);
  8018 
  8019 * HOL/Auth: correctness proofs for authentication protocols;
  8020 
  8021 * HOL: new auto_tac combines rewriting and classical reasoning (many
  8022 examples on HOL/Auth);
  8023 
  8024 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  8025 the rewriter and classical reasoner simultaneously;
  8026 
  8027 * function uresult no longer returns theorems in "standard" format;
  8028 regain previous version by: val uresult = standard o uresult;
  8029 
  8030 
  8031 
  8032 New in Isabelle94-6
  8033 -------------------
  8034 
  8035 * oracles -- these establish an interface between Isabelle and trusted
  8036 external reasoners, which may deliver results as theorems;
  8037 
  8038 * proof objects (in particular record all uses of oracles);
  8039 
  8040 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  8041 
  8042 * "constdefs" section in theory files;
  8043 
  8044 * "primrec" section (HOL) no longer requires names;
  8045 
  8046 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  8047 
  8048 
  8049 
  8050 New in Isabelle94-5
  8051 -------------------
  8052 
  8053 * reduced space requirements;
  8054 
  8055 * automatic HTML generation from theories;
  8056 
  8057 * theory files no longer require "..." (quotes) around most types;
  8058 
  8059 * new examples, including two proofs of the Church-Rosser theorem;
  8060 
  8061 * non-curried (1994) version of HOL is no longer distributed;
  8062 
  8063 
  8064 
  8065 New in Isabelle94-4
  8066 -------------------
  8067 
  8068 * greatly reduced space requirements;
  8069 
  8070 * theory files (.thy) no longer require \...\ escapes at line breaks;
  8071 
  8072 * searchable theorem database (see the section "Retrieving theorems" on
  8073 page 8 of the Reference Manual);
  8074 
  8075 * new examples, including Grabczewski's monumental case study of the
  8076 Axiom of Choice;
  8077 
  8078 * The previous version of HOL renamed to Old_HOL;
  8079 
  8080 * The new version of HOL (previously called CHOL) uses a curried syntax
  8081 for functions.  Application looks like f a b instead of f(a,b);
  8082 
  8083 * Mutually recursive inductive definitions finally work in HOL;
  8084 
  8085 * In ZF, pattern-matching on tuples is now available in all abstractions and
  8086 translates to the operator "split";
  8087 
  8088 
  8089 
  8090 New in Isabelle94-3
  8091 -------------------
  8092 
  8093 * new infix operator, addss, allowing the classical reasoner to
  8094 perform simplification at each step of its search.  Example:
  8095         fast_tac (cs addss ss)
  8096 
  8097 * a new logic, CHOL, the same as HOL, but with a curried syntax
  8098 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  8099 look like (a,b) instead of <a,b>;
  8100 
  8101 * PLEASE NOTE: CHOL will eventually replace HOL!
  8102 
  8103 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  8104 It translates to the operator "split".  A new theory of integers is available;
  8105 
  8106 * In ZF, integer numerals now denote two's-complement binary integers.
  8107 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  8108 
  8109 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  8110 of the Axiom of Choice;
  8111 
  8112 
  8113 
  8114 New in Isabelle94-2
  8115 -------------------
  8116 
  8117 * Significantly faster resolution;
  8118 
  8119 * the different sections in a .thy file can now be mixed and repeated
  8120 freely;
  8121 
  8122 * Database of theorems for FOL, HOL and ZF.  New
  8123 commands including qed, qed_goal and bind_thm store theorems in the database.
  8124 
  8125 * Simple database queries: return a named theorem (get_thm) or all theorems of
  8126 a given theory (thms_of), or find out what theory a theorem was proved in
  8127 (theory_of_thm);
  8128 
  8129 * Bugs fixed in the inductive definition and datatype packages;
  8130 
  8131 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  8132 and HOL_dup_cs obsolete;
  8133 
  8134 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  8135 have been removed;
  8136 
  8137 * Simpler definition of function space in ZF;
  8138 
  8139 * new results about cardinal and ordinal arithmetic in ZF;
  8140 
  8141 * 'subtype' facility in HOL for introducing new types as subsets of existing
  8142 types;
  8143 
  8144 :mode=text:wrap=hard:maxLineLen=72: