NEWS
author wenzelm
Fri May 13 22:55:00 2011 +0200 (2011-05-13)
changeset 42793 88bee9f6eec7
parent 42740 31334a7b109d
child 42809 5b45125b15ba
permissions -rw-r--r--
proper Proof.context for classical tactics;
reduced claset to snapshot of classical context;
discontinued clasimpset;
     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 * Name space: former unsynchronized references are now proper
    41 configuration options, with more conventional names:
    42 
    43   long_names   ~> names_long
    44   short_names  ~> names_short
    45   unique_names ~> names_unique
    46 
    47 Minor INCOMPATIBILITY, need to declare options in context like this:
    48 
    49   declare [[names_unique = false]]
    50 
    51 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
    52 that the result needs to be unique, which means fact specifications
    53 may have to be refined after enriching a proof context.
    54 
    55 * Isabelle/Isar reference manual provides more formal references in
    56 syntax diagrams.
    57 
    58 
    59 *** HOL ***
    60 
    61 * Nitpick:
    62   - Added "need" and "total_consts" options.
    63   - Reintroduced "show_skolems" option by popular demand.
    64   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    65     INCOMPATIBILITY.
    66 
    67 * Sledgehammer:
    68   - sledgehammer available_provers ~> sledgehammer supported_provers
    69     INCOMPATIBILITY.
    70   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
    71     TPTP problems (TFF).
    72   - Added "type_sys", "max_mono_iters", and "max_new_mono_instances" options.
    73 
    74 * "try":
    75   - Added "simp:", "intro:", and "elim:" options.
    76 
    77 * Quickcheck:
    78   - Added "eval" option to evaluate terms for the found counterexample
    79     (currently only supported by the default (exhaustive) tester)
    80   - Added post-processing of terms to obtain readable counterexamples
    81     (currently only supported by the default (exhaustive) tester)
    82 
    83 * Function package: discontinued option "tailrec".
    84 INCOMPATIBILITY. Use partial_function instead.
    85 
    86 * HOL-Probability:
    87   - Caratheodory's extension lemma is now proved for ring_of_sets.
    88   - Infinite products of probability measures are now available.
    89   - Use extended reals instead of positive extended reals.
    90     INCOMPATIBILITY.
    91 
    92 
    93 *** Document preparation ***
    94 
    95 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
    96 isar-ref manual.
    97 
    98 * Localized \isabellestyle switch can be used within blocks or groups
    99 like this:
   100 
   101   \isabellestyle{it}  %preferred default
   102   {\isabellestylett @{text "typewriter stuff"}}
   103 
   104 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   105 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   106 
   107 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   108 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   109 
   110 
   111 *** ML ***
   112 
   113 * Structure Proof_Context follows standard naming scheme.  Old
   114 ProofContext is still available for some time as legacy alias.
   115 
   116 * Structure Timing provides various operations for timing; supersedes
   117 former start_timing/end_timing etc.
   118 
   119 * Path.print is the official way to show file-system paths to users
   120 (including quotes etc.).
   121 
   122 * Inner syntax: identifiers in parse trees of generic categories
   123 "logic", "aprop", "idt" etc. carry position information (disguised as
   124 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   125 translations that choke on unexpected type constraints.  Positions can
   126 be stripped in ML translations via Syntax.strip_positions /
   127 Syntax.strip_positions_ast, or via the syntax constant
   128 "_strip_positions" within parse trees.  As last resort, positions can
   129 be disabled via the configuration option Syntax.positions, which is
   130 called "syntax_positions" in Isar attribute syntax.
   131 
   132 * Discontinued special status of various ML structures that contribute
   133 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   134 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   135 refer directly to Ast.Constant, Lexicon.is_identifier,
   136 Syntax_Trans.mk_binder_tr etc.
   137 
   138 * Typed print translation: discontinued show_sorts argument, which is
   139 already available via context of "advanced" translation.
   140 
   141 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   142 goal states; body tactic needs to address all subgoals uniformly.
   143 
   144 * Slightly more special eq_list/eq_set, with shortcut involving
   145 pointer equality (assumes that eq relation is reflexive).
   146 
   147 * Classical tactics use proper Proof.context instead of historic types
   148 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   149 operate directly on Proof.context.  Raw type claset retains its use as
   150 snapshot of the classical context, which can be recovered via
   151 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   152 INCOMPATIBILITY, classical tactics and derived proof methods require
   153 proper Proof.context.
   154 
   155 
   156 
   157 New in Isabelle2011 (January 2011)
   158 ----------------------------------
   159 
   160 *** General ***
   161 
   162 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   163 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   164 useful tooltips and hyperlinks produced from its static analysis.  The
   165 bundled component provides an executable Isabelle tool that can be run
   166 like this:
   167 
   168   Isabelle2011/bin/isabelle jedit
   169 
   170 * Significantly improved Isabelle/Isar implementation manual.
   171 
   172 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   173 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   174 while the default heap location within that directory lacks that extra
   175 suffix.  This isolates multiple Isabelle installations from each
   176 other, avoiding problems with old settings in new versions.
   177 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   178 
   179 * Source files are always encoded as UTF-8, instead of old-fashioned
   180 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   181 the following package declarations:
   182 
   183   \usepackage[utf8]{inputenc}
   184   \usepackage{textcomp}
   185 
   186 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   187 a Unicode character is treated as a single symbol, not a sequence of
   188 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   189 contain symbols without further backslash escapes, Unicode can now be
   190 used here as well.  Recall that Symbol.explode in ML provides a
   191 consistent view on symbols, while raw explode (or String.explode)
   192 merely give a byte-oriented representation.
   193 
   194 * Theory loader: source files are primarily located via the master
   195 directory of each theory node (where the .thy file itself resides).
   196 The global load path is still partially available as legacy feature.
   197 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   198 explicit paths, relatively to the theory.
   199 
   200 * Special treatment of ML file names has been discontinued.
   201 Historically, optional extensions .ML or .sml were added on demand --
   202 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   203 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   204 
   205 * Various options that affect pretty printing etc. are now properly
   206 handled within the context via configuration options, instead of
   207 unsynchronized references or print modes.  There are both ML Config.T
   208 entities and Isar declaration attributes to access these.
   209 
   210   ML (Config.T)                 Isar (attribute)
   211 
   212   eta_contract                  eta_contract
   213   show_brackets                 show_brackets
   214   show_sorts                    show_sorts
   215   show_types                    show_types
   216   show_question_marks           show_question_marks
   217   show_consts                   show_consts
   218   show_abbrevs                  show_abbrevs
   219 
   220   Syntax.ast_trace              syntax_ast_trace
   221   Syntax.ast_stat               syntax_ast_stat
   222   Syntax.ambiguity_level        syntax_ambiguity_level
   223 
   224   Goal_Display.goals_limit      goals_limit
   225   Goal_Display.show_main_goal   show_main_goal
   226 
   227   Method.rule_trace             rule_trace
   228 
   229   Thy_Output.display            thy_output_display
   230   Thy_Output.quotes             thy_output_quotes
   231   Thy_Output.indent             thy_output_indent
   232   Thy_Output.source             thy_output_source
   233   Thy_Output.break              thy_output_break
   234 
   235 Note that corresponding "..._default" references in ML may only be
   236 changed globally at the ROOT session setup, but *not* within a theory.
   237 The option "show_abbrevs" supersedes the former print mode
   238 "no_abbrevs" with inverted meaning.
   239 
   240 * More systematic naming of some configuration options.
   241 INCOMPATIBILITY.
   242 
   243   trace_simp  ~>  simp_trace
   244   debug_simp  ~>  simp_debug
   245 
   246 * Support for real valued configuration options, using simplistic
   247 floating-point notation that coincides with the inner syntax for
   248 float_token.
   249 
   250 * Support for real valued preferences (with approximative PGIP type):
   251 front-ends need to accept "pgint" values in float notation.
   252 INCOMPATIBILITY.
   253 
   254 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   255 DejaVu Sans.
   256 
   257 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   258 
   259 
   260 *** Pure ***
   261 
   262 * Command 'type_synonym' (with single argument) replaces somewhat
   263 outdated 'types', which is still available as legacy feature for some
   264 time.
   265 
   266 * Command 'nonterminal' (with 'and' separated list of arguments)
   267 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   268 
   269 * Command 'notepad' replaces former 'example_proof' for
   270 experimentation in Isar without any result.  INCOMPATIBILITY.
   271 
   272 * Locale interpretation commands 'interpret' and 'sublocale' accept
   273 lists of equations to map definitions in a locale to appropriate
   274 entities in the context of the interpretation.  The 'interpretation'
   275 command already provided this functionality.
   276 
   277 * Diagnostic command 'print_dependencies' prints the locale instances
   278 that would be activated if the specified expression was interpreted in
   279 the current context.  Variant "print_dependencies!" assumes a context
   280 without interpretations.
   281 
   282 * Diagnostic command 'print_interps' prints interpretations in proofs
   283 in addition to interpretations in theories.
   284 
   285 * Discontinued obsolete 'global' and 'local' commands to manipulate
   286 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   287 Sign.root_path and Sign.local_path may be applied directly where this
   288 feature is still required for historical reasons.
   289 
   290 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   291 'definition' instead.
   292 
   293 * The "prems" fact, which refers to the accidental collection of
   294 foundational premises in the context, is now explicitly marked as
   295 legacy feature and will be discontinued soon.  Consider using "assms"
   296 of the head statement or reference facts by explicit names.
   297 
   298 * Document antiquotations @{class} and @{type} print classes and type
   299 constructors.
   300 
   301 * Document antiquotation @{file} checks file/directory entries within
   302 the local file system.
   303 
   304 
   305 *** HOL ***
   306 
   307 * Coercive subtyping: functions can be declared as coercions and type
   308 inference will add them as necessary upon input of a term.  Theory
   309 Complex_Main declares real :: nat => real and real :: int => real as
   310 coercions. A coercion function f is declared like this:
   311 
   312   declare [[coercion f]]
   313 
   314 To lift coercions through type constructors (e.g. from nat => real to
   315 nat list => real list), map functions can be declared, e.g.
   316 
   317   declare [[coercion_map map]]
   318 
   319 Currently coercion inference is activated only in theories including
   320 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   321 the configuration option "coercion_enabled", e.g. it can be enabled in
   322 other theories like this:
   323 
   324   declare [[coercion_enabled]]
   325 
   326 * Command 'partial_function' provides basic support for recursive
   327 function definitions over complete partial orders.  Concrete instances
   328 are provided for i) the option type, ii) tail recursion on arbitrary
   329 types, and iii) the heap monad of Imperative_HOL.  See
   330 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   331 for examples.
   332 
   333 * Function package: f.psimps rules are no longer implicitly declared
   334 as [simp].  INCOMPATIBILITY.
   335 
   336 * Datatype package: theorems generated for executable equality (class
   337 "eq") carry proper names and are treated as default code equations.
   338 
   339 * Inductive package: now offers command 'inductive_simps' to
   340 automatically derive instantiated and simplified equations for
   341 inductive predicates, similar to 'inductive_cases'.
   342 
   343 * Command 'enriched_type' allows to register properties of the
   344 functorial structure of types.
   345 
   346 * Improved infrastructure for term evaluation using code generator
   347 techniques, in particular static evaluation conversions.
   348 
   349 * Code generator: Scala (2.8 or higher) has been added to the target
   350 languages.
   351 
   352 * Code generator: globbing constant expressions "*" and "Theory.*"
   353 have been replaced by the more idiomatic "_" and "Theory._".
   354 INCOMPATIBILITY.
   355 
   356 * Code generator: export_code without explicit file declaration prints
   357 to standard output.  INCOMPATIBILITY.
   358 
   359 * Code generator: do not print function definitions for case
   360 combinators any longer.
   361 
   362 * Code generator: simplification with rules determined with
   363 src/Tools/Code/code_simp.ML and method "code_simp".
   364 
   365 * Code generator for records: more idiomatic representation of record
   366 types.  Warning: records are not covered by ancient SML code
   367 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   368 rep_datatype declaration helps to succeed then:
   369 
   370   record 'a foo = ...
   371   ...
   372   rep_datatype foo_ext ...
   373 
   374 * Records: logical foundation type for records does not carry a
   375 '_type' suffix any longer (obsolete due to authentic syntax).
   376 INCOMPATIBILITY.
   377 
   378 * Quickcheck now by default uses exhaustive testing instead of random
   379 testing.  Random testing can be invoked by "quickcheck [random]",
   380 exhaustive testing by "quickcheck [exhaustive]".
   381 
   382 * Quickcheck instantiates polymorphic types with small finite
   383 datatypes by default. This enables a simple execution mechanism to
   384 handle quantifiers and function equality over the finite datatypes.
   385 
   386 * Quickcheck random generator has been renamed from "code" to
   387 "random".  INCOMPATIBILITY.
   388 
   389 * Quickcheck now has a configurable time limit which is set to 30
   390 seconds by default. This can be changed by adding [timeout = n] to the
   391 quickcheck command. The time limit for Auto Quickcheck is still set
   392 independently.
   393 
   394 * Quickcheck in locales considers interpretations of that locale for
   395 counter example search.
   396 
   397 * Sledgehammer:
   398   - Added "smt" and "remote_smt" provers based on the "smt" proof
   399     method. See the Sledgehammer manual for details ("isabelle doc
   400     sledgehammer").
   401   - Renamed commands:
   402     sledgehammer atp_info ~> sledgehammer running_provers
   403     sledgehammer atp_kill ~> sledgehammer kill_provers
   404     sledgehammer available_atps ~> sledgehammer available_provers
   405     INCOMPATIBILITY.
   406   - Renamed options:
   407     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   408     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   409     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   410     (and "ms" and "min" are no longer supported)
   411     INCOMPATIBILITY.
   412 
   413 * Nitpick:
   414   - Renamed options:
   415     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   416     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   417     INCOMPATIBILITY.
   418   - Added support for partial quotient types.
   419   - Added local versions of the "Nitpick.register_xxx" functions.
   420   - Added "whack" option.
   421   - Allow registration of quotient types as codatatypes.
   422   - Improved "merge_type_vars" option to merge more types.
   423   - Removed unsound "fast_descrs" option.
   424   - Added custom symmetry breaking for datatypes, making it possible to reach
   425     higher cardinalities.
   426   - Prevent the expansion of too large definitions.
   427 
   428 * Proof methods "metis" and "meson" now have configuration options
   429 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   430 to diagnose these tools. E.g.
   431 
   432     using [[metis_trace = true]]
   433 
   434 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   435 manually as command 'solve_direct'.
   436 
   437 * The default SMT solver Z3 must be enabled explicitly (due to
   438 licensing issues) by setting the environment variable
   439 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   440 commercial applications, the SMT solver CVC3 is provided as fall-back;
   441 changing the SMT solver is done via the configuration option
   442 "smt_solver".
   443 
   444 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   445 i.e. "remote_cvc3" and "remote_z3".
   446 
   447 * Added basic SMT support for datatypes, records, and typedefs using
   448 the oracle mode (no proofs).  Direct support of pairs has been dropped
   449 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   450 support for a similar behavior).  Minor INCOMPATIBILITY.
   451 
   452 * Changed SMT configuration options:
   453   - Renamed:
   454     z3_proofs ~> smt_oracle (with inverted meaning)
   455     z3_trace_assms ~> smt_trace_used_facts
   456     INCOMPATIBILITY.
   457   - Added:
   458     smt_verbose
   459     smt_random_seed
   460     smt_datatypes
   461     smt_infer_triggers
   462     smt_monomorph_limit
   463     cvc3_options
   464     remote_cvc3_options
   465     remote_z3_options
   466     yices_options
   467 
   468 * Boogie output files (.b2i files) need to be declared in the theory
   469 header.
   470 
   471 * Simplification procedure "list_to_set_comprehension" rewrites list
   472 comprehensions applied to List.set to set comprehensions.  Occasional
   473 INCOMPATIBILITY, may be deactivated like this:
   474 
   475   declare [[simproc del: list_to_set_comprehension]]
   476 
   477 * Removed old version of primrec package.  INCOMPATIBILITY.
   478 
   479 * Removed simplifier congruence rule of "prod_case", as has for long
   480 been the case with "split".  INCOMPATIBILITY.
   481 
   482 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   483 
   484 * Removed [split_format ... and ... and ...] version of
   485 [split_format].  Potential INCOMPATIBILITY.
   486 
   487 * Predicate "sorted" now defined inductively, with nice induction
   488 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   489 
   490 * Constant "contents" renamed to "the_elem", to free the generic name
   491 contents for other uses.  INCOMPATIBILITY.
   492 
   493 * Renamed class eq and constant eq (for code generation) to class
   494 equal and constant equal, plus renaming of related facts and various
   495 tuning.  INCOMPATIBILITY.
   496 
   497 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   498 
   499 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   500 INCOMPATIBILITY.
   501 
   502 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   503 avoid confusion with finite sets.  INCOMPATIBILITY.
   504 
   505 * Abandoned locales equiv, congruent and congruent2 for equivalence
   506 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   507 for congruent(2)).
   508 
   509 * Some previously unqualified names have been qualified:
   510 
   511   types
   512     bool ~> HOL.bool
   513     nat ~> Nat.nat
   514 
   515   constants
   516     Trueprop ~> HOL.Trueprop
   517     True ~> HOL.True
   518     False ~> HOL.False
   519     op & ~> HOL.conj
   520     op | ~> HOL.disj
   521     op --> ~> HOL.implies
   522     op = ~> HOL.eq
   523     Not ~> HOL.Not
   524     The ~> HOL.The
   525     All ~> HOL.All
   526     Ex ~> HOL.Ex
   527     Ex1 ~> HOL.Ex1
   528     Let ~> HOL.Let
   529     If ~> HOL.If
   530     Ball ~> Set.Ball
   531     Bex ~> Set.Bex
   532     Suc ~> Nat.Suc
   533     Pair ~> Product_Type.Pair
   534     fst ~> Product_Type.fst
   535     snd ~> Product_Type.snd
   536     curry ~> Product_Type.curry
   537     op : ~> Set.member
   538     Collect ~> Set.Collect
   539 
   540 INCOMPATIBILITY.
   541 
   542 * More canonical naming convention for some fundamental definitions:
   543 
   544     bot_bool_eq ~> bot_bool_def
   545     top_bool_eq ~> top_bool_def
   546     inf_bool_eq ~> inf_bool_def
   547     sup_bool_eq ~> sup_bool_def
   548     bot_fun_eq  ~> bot_fun_def
   549     top_fun_eq  ~> top_fun_def
   550     inf_fun_eq  ~> inf_fun_def
   551     sup_fun_eq  ~> sup_fun_def
   552 
   553 INCOMPATIBILITY.
   554 
   555 * More stylized fact names:
   556 
   557   expand_fun_eq ~> fun_eq_iff
   558   expand_set_eq ~> set_eq_iff
   559   set_ext       ~> set_eqI
   560   nat_number    ~> eval_nat_numeral
   561 
   562 INCOMPATIBILITY.
   563 
   564 * Refactoring of code-generation specific operations in theory List:
   565 
   566   constants
   567     null ~> List.null
   568 
   569   facts
   570     mem_iff ~> member_def
   571     null_empty ~> null_def
   572 
   573 INCOMPATIBILITY.  Note that these were not supposed to be used
   574 regularly unless for striking reasons; their main purpose was code
   575 generation.
   576 
   577 Various operations from the Haskell prelude are used for generating
   578 Haskell code.
   579 
   580 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   581 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   582 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   583 
   584 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   585 "*" and "+" respectively.  INCOMPATIBILITY.
   586 
   587 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   588 "Sum_Type.Plus" instead.
   589 
   590 * Constant "split" has been merged with constant "prod_case"; names of
   591 ML functions, facts etc. involving split have been retained so far,
   592 though.  INCOMPATIBILITY.
   593 
   594 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   595 instead.  INCOMPATIBILITY.
   596 
   597 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   598 INCOMPATIBILITY.
   599 
   600 * Former theory Library/Enum is now part of the HOL-Main image.
   601 INCOMPATIBILITY: all constants of the Enum theory now have to be
   602 referred to by its qualified name.
   603 
   604   enum    ~>  Enum.enum
   605   nlists  ~>  Enum.nlists
   606   product ~>  Enum.product
   607 
   608 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   609 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   610 INCOMPATIBILITY.
   611 
   612 * Theory Library/SetsAndFunctions has been split into
   613 Library/Function_Algebras and Library/Set_Algebras; canonical names
   614 for instance definitions for functions; various improvements.
   615 INCOMPATIBILITY.
   616 
   617 * Theory Library/Multiset provides stable quicksort implementation of
   618 sort_key.
   619 
   620 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   621 INCOMPATIBILITY.
   622 
   623 * Session Multivariate_Analysis: introduced a type class for euclidean
   624 space.  Most theorems are now stated in terms of euclidean spaces
   625 instead of finite cartesian products.
   626 
   627   types
   628     real ^ 'n ~>  'a::real_vector
   629               ~>  'a::euclidean_space
   630               ~>  'a::ordered_euclidean_space
   631         (depends on your needs)
   632 
   633   constants
   634      _ $ _        ~> _ $$ _
   635      \<chi> x. _  ~> \<chi>\<chi> x. _
   636      CARD('n)     ~> DIM('a)
   637 
   638 Also note that the indices are now natural numbers and not from some
   639 finite type. Finite cartesian products of euclidean spaces, products
   640 of euclidean spaces the real and complex numbers are instantiated to
   641 be euclidean_spaces.  INCOMPATIBILITY.
   642 
   643 * Session Probability: introduced pextreal as positive extended real
   644 numbers.  Use pextreal as value for measures.  Introduce the
   645 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   646 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   647 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   648 
   649 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   650 INCOMPATIBILITY.
   651 
   652 * Session SPARK (with image HOL-SPARK) provides commands to load and
   653 prove verification conditions generated by the SPARK Ada program
   654 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   655 
   656 
   657 *** HOL-Algebra ***
   658 
   659 * Theorems for additive ring operations (locale abelian_monoid and
   660 descendants) are generated by interpretation from their multiplicative
   661 counterparts.  Names (in particular theorem names) have the mandatory
   662 qualifier 'add'.  Previous theorem names are redeclared for
   663 compatibility.
   664 
   665 * Structure "int_ring" is now an abbreviation (previously a
   666 definition).  This fits more natural with advanced interpretations.
   667 
   668 
   669 *** HOLCF ***
   670 
   671 * The domain package now runs in definitional mode by default: The
   672 former command 'new_domain' is now called 'domain'.  To use the domain
   673 package in its original axiomatic mode, use 'domain (unsafe)'.
   674 INCOMPATIBILITY.
   675 
   676 * The new class "domain" is now the default sort.  Class "predomain"
   677 is an unpointed version of "domain". Theories can be updated by
   678 replacing sort annotations as shown below.  INCOMPATIBILITY.
   679 
   680   'a::type ~> 'a::countable
   681   'a::cpo  ~> 'a::predomain
   682   'a::pcpo ~> 'a::domain
   683 
   684 * The old type class "rep" has been superseded by class "domain".
   685 Accordingly, users of the definitional package must remove any
   686 "default_sort rep" declarations.  INCOMPATIBILITY.
   687 
   688 * The domain package (definitional mode) now supports unpointed
   689 predomain argument types, as long as they are marked 'lazy'. (Strict
   690 arguments must be in class "domain".) For example, the following
   691 domain definition now works:
   692 
   693   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   694 
   695 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   696 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   697 'a option, and 'a list.  Additionally, it configures fixrec and the
   698 domain package to work with these types.  For example:
   699 
   700   fixrec isInl :: "('a + 'b) u -> tr"
   701     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   702 
   703   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   704 
   705 * The "(permissive)" option of fixrec has been replaced with a
   706 per-equation "(unchecked)" option. See
   707 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   708 
   709 * The "bifinite" class no longer fixes a constant "approx"; the class
   710 now just asserts that such a function exists.  INCOMPATIBILITY.
   711 
   712 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   713 defines an embedding of type 'a defl into udom by default; instances
   714 of "bifinite" and "domain" classes are available in
   715 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   716 
   717 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   718 
   719 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   720 
   721 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   722 
   723 * The function "cprod_map" has been renamed to "prod_map".
   724 INCOMPATIBILITY.
   725 
   726 * The monadic bind operator on each powerdomain has new binder syntax
   727 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   728 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   729 
   730 * The infix syntax for binary union on each powerdomain has changed
   731 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   732 syntax.  INCOMPATIBILITY.
   733 
   734 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   735 still supported as an input translation.
   736 
   737 * Renamed some theorems (the original names are also still available).
   738 
   739   expand_fun_below   ~> fun_below_iff
   740   below_fun_ext      ~> fun_belowI
   741   expand_cfun_eq     ~> cfun_eq_iff
   742   ext_cfun           ~> cfun_eqI
   743   expand_cfun_below  ~> cfun_below_iff
   744   below_cfun_ext     ~> cfun_belowI
   745   cont2cont_Rep_CFun ~> cont2cont_APP
   746 
   747 * The Abs and Rep functions for various types have changed names.
   748 Related theorem names have also changed to match. INCOMPATIBILITY.
   749 
   750   Rep_CFun  ~> Rep_cfun
   751   Abs_CFun  ~> Abs_cfun
   752   Rep_Sprod ~> Rep_sprod
   753   Abs_Sprod ~> Abs_sprod
   754   Rep_Ssum  ~> Rep_ssum
   755   Abs_Ssum  ~> Abs_ssum
   756 
   757 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   758 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   759 
   760 * Various changes to bisimulation/coinduction with domain package:
   761 
   762   - Definitions of "bisim" constants no longer mention definedness.
   763   - With mutual recursion, "bisim" predicate is now curried.
   764   - With mutual recursion, each type gets a separate coind theorem.
   765   - Variable names in bisim_def and coinduct rules have changed.
   766 
   767 INCOMPATIBILITY.
   768 
   769 * Case combinators generated by the domain package for type "foo" are
   770 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   771 
   772 * Several theorems have been renamed to more accurately reflect the
   773 names of constants and types involved.  INCOMPATIBILITY.
   774 
   775   thelub_const    ~> lub_const
   776   lub_const       ~> is_lub_const
   777   thelubI         ~> lub_eqI
   778   is_lub_lub      ~> is_lubD2
   779   lubI            ~> is_lub_lub
   780   unique_lub      ~> is_lub_unique
   781   is_ub_lub       ~> is_lub_rangeD1
   782   lub_bin_chain   ~> is_lub_bin_chain
   783   lub_fun         ~> is_lub_fun
   784   thelub_fun      ~> lub_fun
   785   thelub_cfun     ~> lub_cfun
   786   thelub_Pair     ~> lub_Pair
   787   lub_cprod       ~> is_lub_prod
   788   thelub_cprod    ~> lub_prod
   789   minimal_cprod   ~> minimal_prod
   790   inst_cprod_pcpo ~> inst_prod_pcpo
   791   UU_I            ~> bottomI
   792   compact_UU      ~> compact_bottom
   793   deflation_UU    ~> deflation_bottom
   794   finite_deflation_UU ~> finite_deflation_bottom
   795 
   796 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   797 
   798   sq_ord_less_eq_trans ~> below_eq_trans
   799   sq_ord_eq_less_trans ~> eq_below_trans
   800   refl_less            ~> below_refl
   801   trans_less           ~> below_trans
   802   antisym_less         ~> below_antisym
   803   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   804   box_less             ~> box_below
   805   rev_trans_less       ~> rev_below_trans
   806   not_less2not_eq      ~> not_below2not_eq
   807   less_UU_iff          ~> below_UU_iff
   808   flat_less_iff        ~> flat_below_iff
   809   adm_less             ~> adm_below
   810   adm_not_less         ~> adm_not_below
   811   adm_compact_not_less ~> adm_compact_not_below
   812   less_fun_def         ~> below_fun_def
   813   expand_fun_less      ~> fun_below_iff
   814   less_fun_ext         ~> fun_belowI
   815   less_discr_def       ~> below_discr_def
   816   discr_less_eq        ~> discr_below_eq
   817   less_unit_def        ~> below_unit_def
   818   less_cprod_def       ~> below_prod_def
   819   prod_lessI           ~> prod_belowI
   820   Pair_less_iff        ~> Pair_below_iff
   821   fst_less_iff         ~> fst_below_iff
   822   snd_less_iff         ~> snd_below_iff
   823   expand_cfun_less     ~> cfun_below_iff
   824   less_cfun_ext        ~> cfun_belowI
   825   injection_less       ~> injection_below
   826   less_up_def          ~> below_up_def
   827   not_Iup_less         ~> not_Iup_below
   828   Iup_less             ~> Iup_below
   829   up_less              ~> up_below
   830   Def_inject_less_eq   ~> Def_below_Def
   831   Def_less_is_eq       ~> Def_below_iff
   832   spair_less_iff       ~> spair_below_iff
   833   less_sprod           ~> below_sprod
   834   spair_less           ~> spair_below
   835   sfst_less_iff        ~> sfst_below_iff
   836   ssnd_less_iff        ~> ssnd_below_iff
   837   fix_least_less       ~> fix_least_below
   838   dist_less_one        ~> dist_below_one
   839   less_ONE             ~> below_ONE
   840   ONE_less_iff         ~> ONE_below_iff
   841   less_sinlD           ~> below_sinlD
   842   less_sinrD           ~> below_sinrD
   843 
   844 
   845 *** FOL and ZF ***
   846 
   847 * All constant names are now qualified internally and use proper
   848 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   849 
   850 
   851 *** ML ***
   852 
   853 * Antiquotation @{assert} inlines a function bool -> unit that raises
   854 Fail if the argument is false.  Due to inlining the source position of
   855 failed assertions is included in the error output.
   856 
   857 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   858 text is in practice always evaluated with a stable theory checkpoint.
   859 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   860 
   861 * Antiquotation @{theory A} refers to theory A from the ancestry of
   862 the current context, not any accidental theory loader state as before.
   863 Potential INCOMPATIBILITY, subtle change in semantics.
   864 
   865 * Syntax.pretty_priority (default 0) configures the required priority
   866 of pretty-printed output and thus affects insertion of parentheses.
   867 
   868 * Syntax.default_root (default "any") configures the inner syntax
   869 category (nonterminal symbol) for parsing of terms.
   870 
   871 * Former exception Library.UnequalLengths now coincides with
   872 ListPair.UnequalLengths.
   873 
   874 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   875 main functionality is provided by structure Simplifier.
   876 
   877 * Renamed raw "explode" function to "raw_explode" to emphasize its
   878 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   879 almost all situations.
   880 
   881 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   882 See implementation manual for further details on exceptions in
   883 Isabelle/ML.
   884 
   885 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   886 meaning.
   887 
   888 * Renamed structure PureThy to Pure_Thy and moved most of its
   889 operations to structure Global_Theory, to emphasize that this is
   890 rarely-used global-only stuff.
   891 
   892 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   893 instead (or tracing for high-volume output).
   894 
   895 * Configuration option show_question_marks only affects regular pretty
   896 printing of types and terms, not raw Term.string_of_vname.
   897 
   898 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   899 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   900 @{thms} for most purposes.
   901 
   902 * ML structure Unsynchronized is never opened, not even in Isar
   903 interaction mode as before.  Old Unsynchronized.set etc. have been
   904 discontinued -- use plain := instead.  This should be *rare* anyway,
   905 since modern tools always work via official context data, notably
   906 configuration options.
   907 
   908 * Parallel and asynchronous execution requires special care concerning
   909 interrupts.  Structure Exn provides some convenience functions that
   910 avoid working directly with raw Interrupt.  User code must not absorb
   911 interrupts -- intermediate handling (for cleanup etc.) needs to be
   912 followed by re-raising of the original exception.  Another common
   913 source of mistakes are "handle _" patterns, which make the meaning of
   914 the program subject to physical effects of the environment.
   915 
   916 
   917 
   918 New in Isabelle2009-2 (June 2010)
   919 ---------------------------------
   920 
   921 *** General ***
   922 
   923 * Authentic syntax for *all* logical entities (type classes, type
   924 constructors, term constants): provides simple and robust
   925 correspondence between formal entities and concrete syntax.  Within
   926 the parse tree / AST representations, "constants" are decorated by
   927 their category (class, type, const) and spelled out explicitly with
   928 their full internal name.
   929 
   930 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   931 and translations (translation rules and translation functions in ML).
   932 Some hints on upgrading:
   933 
   934   - Many existing uses of 'syntax' and 'translations' can be replaced
   935     by more modern 'type_notation', 'notation' and 'abbreviation',
   936     which are independent of this issue.
   937 
   938   - 'translations' require markup within the AST; the term syntax
   939     provides the following special forms:
   940 
   941       CONST c   -- produces syntax version of constant c from context
   942       XCONST c  -- literally c, checked as constant from context
   943       c         -- literally c, if declared by 'syntax'
   944 
   945     Plain identifiers are treated as AST variables -- occasionally the
   946     system indicates accidental variables via the error "rhs contains
   947     extra variables".
   948 
   949     Type classes and type constructors are marked according to their
   950     concrete syntax.  Some old translations rules need to be written
   951     for the "type" category, using type constructor application
   952     instead of pseudo-term application of the default category
   953     "logic".
   954 
   955   - 'parse_translation' etc. in ML may use the following
   956     antiquotations:
   957 
   958       @{class_syntax c}   -- type class c within parse tree / AST
   959       @{term_syntax c}    -- type constructor c within parse tree / AST
   960       @{const_syntax c}   -- ML version of "CONST c" above
   961       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   962 
   963   - Literal types within 'typed_print_translations', i.e. those *not*
   964     represented as pseudo-terms are represented verbatim.  Use @{class
   965     c} or @{type_name c} here instead of the above syntax
   966     antiquotations.
   967 
   968 Note that old non-authentic syntax was based on unqualified base
   969 names, so all of the above "constant" names would coincide.  Recall
   970 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   971 diagnose syntax problems.
   972 
   973 * Type constructors admit general mixfix syntax, not just infix.
   974 
   975 * Concrete syntax may be attached to local entities without a proof
   976 body, too.  This works via regular mixfix annotations for 'fix',
   977 'def', 'obtain' etc. or via the explicit 'write' command, which is
   978 similar to the 'notation' command in theory specifications.
   979 
   980 * Discontinued unnamed infix syntax (legacy feature for many years) --
   981 need to specify constant name and syntax separately.  Internal ML
   982 datatype constructors have been renamed from InfixName to Infix etc.
   983 Minor INCOMPATIBILITY.
   984 
   985 * Schematic theorem statements need to be explicitly markup as such,
   986 via commands 'schematic_lemma', 'schematic_theorem',
   987 'schematic_corollary'.  Thus the relevance of the proof is made
   988 syntactically clear, which impacts performance in a parallel or
   989 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   990 
   991 * Use of cumulative prems via "!" in some proof methods has been
   992 discontinued (old legacy feature).
   993 
   994 * References 'trace_simp' and 'debug_simp' have been replaced by
   995 configuration options stored in the context. Enabling tracing (the
   996 case of debugging is similar) in proofs works via
   997 
   998   using [[trace_simp = true]]
   999 
  1000 Tracing is then active for all invocations of the simplifier in
  1001 subsequent goal refinement steps. Tracing may also still be enabled or
  1002 disabled via the ProofGeneral settings menu.
  1003 
  1004 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1005 'hide_fact' replace the former 'hide' KIND command.  Minor
  1006 INCOMPATIBILITY.
  1007 
  1008 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1009 more efficient than combinations with -q1 or -q2.
  1010 
  1011 
  1012 *** Pure ***
  1013 
  1014 * Proofterms record type-class reasoning explicitly, using the
  1015 "unconstrain" operation internally.  This eliminates all sort
  1016 constraints from a theorem and proof, introducing explicit
  1017 OFCLASS-premises.  On the proof term level, this operation is
  1018 automatically applied at theorem boundaries, such that closed proofs
  1019 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1020 inspect proof terms.
  1021 
  1022 * Local theory specifications may depend on extra type variables that
  1023 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1024 are added internally.  For example:
  1025 
  1026   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1027 
  1028 * Predicates of locales introduced by classes carry a mandatory
  1029 "class" prefix.  INCOMPATIBILITY.
  1030 
  1031 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1032 
  1033 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1034 'class' instead.
  1035 
  1036 * Command 'code_reflect' allows to incorporate generated ML code into
  1037 runtime environment; replaces immature code_datatype antiquotation.
  1038 INCOMPATIBILITY.
  1039 
  1040 * Code generator: simple concept for abstract datatypes obeying
  1041 invariants.
  1042 
  1043 * Code generator: details of internal data cache have no impact on the
  1044 user space functionality any longer.
  1045 
  1046 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1047 subgoals.  This is more appropriate for interpretations with 'where'.
  1048 INCOMPATIBILITY.
  1049 
  1050 * Command 'example_proof' opens an empty proof body.  This allows to
  1051 experiment with Isar, without producing any persistent result.
  1052 
  1053 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1054 within a local theory context, with explicit checking of the
  1055 constructors involved (in contrast to the raw 'syntax' versions).
  1056 
  1057 * Commands 'types' and 'typedecl' now work within a local theory
  1058 context -- without introducing dependencies on parameters or
  1059 assumptions, which is not possible in Isabelle/Pure.
  1060 
  1061 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1062 within a local theory context.  Minor INCOMPATIBILITY.
  1063 
  1064 
  1065 *** HOL ***
  1066 
  1067 * Command 'typedef' now works within a local theory context -- without
  1068 introducing dependencies on parameters or assumptions, which is not
  1069 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1070 contain multiple interpretations of local typedefs (with different
  1071 non-emptiness proofs), even in a global theory context.
  1072 
  1073 * New package for quotient types.  Commands 'quotient_type' and
  1074 'quotient_definition' may be used for defining types and constants by
  1075 quotient constructions.  An example is the type of integers created by
  1076 quotienting pairs of natural numbers:
  1077 
  1078   fun
  1079     intrel :: "(nat * nat) => (nat * nat) => bool"
  1080   where
  1081     "intrel (x, y) (u, v) = (x + v = u + y)"
  1082 
  1083   quotient_type int = "nat * nat" / intrel
  1084     by (auto simp add: equivp_def expand_fun_eq)
  1085 
  1086   quotient_definition
  1087     "0::int" is "(0::nat, 0::nat)"
  1088 
  1089 The method "lifting" can be used to lift of theorems from the
  1090 underlying "raw" type to the quotient type.  The example
  1091 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1092 construction and provides a reasoning infrastructure for finite sets.
  1093 
  1094 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1095 clash with new theory Quotient in Main HOL.
  1096 
  1097 * Moved the SMT binding into the main HOL session, eliminating
  1098 separate HOL-SMT session.
  1099 
  1100 * List membership infix mem operation is only an input abbreviation.
  1101 INCOMPATIBILITY.
  1102 
  1103 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1104 for future developements; former Library/Word.thy is still present in
  1105 the AFP entry RSAPPS.
  1106 
  1107 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1108 longer shadowed.  INCOMPATIBILITY.
  1109 
  1110 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1111 INCOMPATIBILITY.
  1112 
  1113 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1114 INCOMPATIBILITY.
  1115 
  1116 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1117 instead.  INCOMPATIBILITY.
  1118 
  1119 * Dropped several real-specific versions of lemmas about floor and
  1120 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1121 instead.  INCOMPATIBILITY.
  1122 
  1123   floor_number_of_eq         ~> floor_number_of
  1124   le_floor_eq_number_of      ~> number_of_le_floor
  1125   le_floor_eq_zero           ~> zero_le_floor
  1126   le_floor_eq_one            ~> one_le_floor
  1127   floor_less_eq_number_of    ~> floor_less_number_of
  1128   floor_less_eq_zero         ~> floor_less_zero
  1129   floor_less_eq_one          ~> floor_less_one
  1130   less_floor_eq_number_of    ~> number_of_less_floor
  1131   less_floor_eq_zero         ~> zero_less_floor
  1132   less_floor_eq_one          ~> one_less_floor
  1133   floor_le_eq_number_of      ~> floor_le_number_of
  1134   floor_le_eq_zero           ~> floor_le_zero
  1135   floor_le_eq_one            ~> floor_le_one
  1136   floor_subtract_number_of   ~> floor_diff_number_of
  1137   floor_subtract_one         ~> floor_diff_one
  1138   ceiling_number_of_eq       ~> ceiling_number_of
  1139   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1140   ceiling_le_zero_eq         ~> ceiling_le_zero
  1141   ceiling_le_eq_one          ~> ceiling_le_one
  1142   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1143   less_ceiling_eq_zero       ~> zero_less_ceiling
  1144   less_ceiling_eq_one        ~> one_less_ceiling
  1145   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1146   ceiling_less_eq_zero       ~> ceiling_less_zero
  1147   ceiling_less_eq_one        ~> ceiling_less_one
  1148   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1149   le_ceiling_eq_zero         ~> zero_le_ceiling
  1150   le_ceiling_eq_one          ~> one_le_ceiling
  1151   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1152   ceiling_subtract_one       ~> ceiling_diff_one
  1153 
  1154 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1155 application of the various fold combinators on finite sets.
  1156 
  1157 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1158 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1159 implementation.  INCOMPATIBILTY.
  1160 
  1161 * Theory Library/Coinductive_List has been removed -- superseded by
  1162 AFP/thys/Coinductive.
  1163 
  1164 * Theory PReal, including the type "preal" and related operations, has
  1165 been removed.  INCOMPATIBILITY.
  1166 
  1167 * Real: new development using Cauchy Sequences.
  1168 
  1169 * Split off theory "Big_Operators" containing setsum, setprod,
  1170 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1171 
  1172 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1173 "Int" etc.  INCOMPATIBILITY.
  1174 
  1175 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1176 
  1177 * New set of rules "ac_simps" provides combined assoc / commute
  1178 rewrites for all interpretations of the appropriate generic locales.
  1179 
  1180 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1181 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1182 appropriate and more consistent names suitable for name prefixes
  1183 within the HOL theories.  INCOMPATIBILITY.
  1184 
  1185 * Some generic constants have been put to appropriate theories:
  1186   - less_eq, less: Orderings
  1187   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1188   - inverse, divide: Rings
  1189 INCOMPATIBILITY.
  1190 
  1191 * More consistent naming of type classes involving orderings (and
  1192 lattices):
  1193 
  1194     lower_semilattice                   ~> semilattice_inf
  1195     upper_semilattice                   ~> semilattice_sup
  1196 
  1197     dense_linear_order                  ~> dense_linorder
  1198 
  1199     pordered_ab_group_add               ~> ordered_ab_group_add
  1200     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1201     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1202     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1203     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1204     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1205     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1206     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1207     pordered_comm_ring                  ~> ordered_comm_ring
  1208     pordered_comm_semiring              ~> ordered_comm_semiring
  1209     pordered_ring                       ~> ordered_ring
  1210     pordered_ring_abs                   ~> ordered_ring_abs
  1211     pordered_semiring                   ~> ordered_semiring
  1212 
  1213     ordered_ab_group_add                ~> linordered_ab_group_add
  1214     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1215     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1216     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1217     ordered_field                       ~> linordered_field
  1218     ordered_field_no_lb                 ~> linordered_field_no_lb
  1219     ordered_field_no_ub                 ~> linordered_field_no_ub
  1220     ordered_field_dense_linear_order    ~> dense_linordered_field
  1221     ordered_idom                        ~> linordered_idom
  1222     ordered_ring                        ~> linordered_ring
  1223     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1224     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1225     ordered_ring_strict                 ~> linordered_ring_strict
  1226     ordered_semidom                     ~> linordered_semidom
  1227     ordered_semiring                    ~> linordered_semiring
  1228     ordered_semiring_1                  ~> linordered_semiring_1
  1229     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1230     ordered_semiring_strict             ~> linordered_semiring_strict
  1231 
  1232   The following slightly odd type classes have been moved to a
  1233   separate theory Library/Lattice_Algebras:
  1234 
  1235     lordered_ab_group_add               ~> lattice_ab_group_add
  1236     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1237     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1238     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1239     lordered_ring                       ~> lattice_ring
  1240 
  1241 INCOMPATIBILITY.
  1242 
  1243 * Refined field classes:
  1244   - classes division_ring_inverse_zero, field_inverse_zero,
  1245     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1246     subsumes former division_by_zero class;
  1247   - numerous lemmas have been ported from field to division_ring.
  1248 INCOMPATIBILITY.
  1249 
  1250 * Refined algebra theorem collections:
  1251   - dropped theorem group group_simps, use algebra_simps instead;
  1252   - dropped theorem group ring_simps, use field_simps instead;
  1253   - proper theorem collection field_simps subsumes former theorem
  1254     groups field_eq_simps and field_simps;
  1255   - dropped lemma eq_minus_self_iff which is a duplicate for
  1256     equal_neg_zero.
  1257 INCOMPATIBILITY.
  1258 
  1259 * Theory Finite_Set and List: some lemmas have been generalized from
  1260 sets to lattices:
  1261 
  1262   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1263   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1264   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1265   union_Union_fold_union        ~> sup_Sup_fold_sup
  1266   Inter_fold_inter              ~> Inf_fold_inf
  1267   Union_fold_union              ~> Sup_fold_sup
  1268   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1269   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1270   INTER_fold_inter              ~> INFI_fold_inf
  1271   UNION_fold_union              ~> SUPR_fold_sup
  1272 
  1273 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1274 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1275 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1276 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1277 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1278 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1279 
  1280 * Reorganized theory Multiset: swapped notation of pointwise and
  1281 multiset order:
  1282 
  1283   - pointwise ordering is instance of class order with standard syntax
  1284     <= and <;
  1285   - multiset ordering has syntax <=# and <#; partial order properties
  1286     are provided by means of interpretation with prefix
  1287     multiset_order;
  1288   - less duplication, less historical organization of sections,
  1289     conversion from associations lists to multisets, rudimentary code
  1290     generation;
  1291   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1292     if needed.
  1293 
  1294 Renamed:
  1295 
  1296   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1297   multi_count_ext  ~>  multiset_ext
  1298   diff_union_inverse2  ~>  diff_union_cancelR
  1299 
  1300 INCOMPATIBILITY.
  1301 
  1302 * Theory Permutation: replaced local "remove" by List.remove1.
  1303 
  1304 * Code generation: ML and OCaml code is decorated with signatures.
  1305 
  1306 * Theory List: added transpose.
  1307 
  1308 * Library/Nat_Bijection.thy is a collection of bijective functions
  1309 between nat and other types, which supersedes the older libraries
  1310 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1311 
  1312   Constants:
  1313   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1314   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1315   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1316   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1317   Countable.pair_encode           ~> prod_encode
  1318   NatIso.prod2nat                 ~> prod_encode
  1319   NatIso.nat2prod                 ~> prod_decode
  1320   NatIso.sum2nat                  ~> sum_encode
  1321   NatIso.nat2sum                  ~> sum_decode
  1322   NatIso.list2nat                 ~> list_encode
  1323   NatIso.nat2list                 ~> list_decode
  1324   NatIso.set2nat                  ~> set_encode
  1325   NatIso.nat2set                  ~> set_decode
  1326 
  1327   Lemmas:
  1328   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1329   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1330   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1331   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1332   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1333   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1334   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1335   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1336   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1337   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1338   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1339   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1340   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1341 
  1342 * Sledgehammer:
  1343   - Renamed ATP commands:
  1344     atp_info     ~> sledgehammer running_atps
  1345     atp_kill     ~> sledgehammer kill_atps
  1346     atp_messages ~> sledgehammer messages
  1347     atp_minimize ~> sledgehammer minimize
  1348     print_atps   ~> sledgehammer available_atps
  1349     INCOMPATIBILITY.
  1350   - Added user's manual ("isabelle doc sledgehammer").
  1351   - Added option syntax and "sledgehammer_params" to customize
  1352     Sledgehammer's behavior.  See the manual for details.
  1353   - Modified the Isar proof reconstruction code so that it produces
  1354     direct proofs rather than proofs by contradiction.  (This feature
  1355     is still experimental.)
  1356   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1357     full-typed mode.
  1358   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1359 
  1360 * Nitpick:
  1361   - Added and implemented "binary_ints" and "bits" options.
  1362   - Added "std" option and implemented support for nonstandard models.
  1363   - Added and implemented "finitize" option to improve the precision
  1364     of infinite datatypes based on a monotonicity analysis.
  1365   - Added support for quotient types.
  1366   - Added support for "specification" and "ax_specification"
  1367     constructs.
  1368   - Added support for local definitions (for "function" and
  1369     "termination" proofs).
  1370   - Added support for term postprocessors.
  1371   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1372   - Improved efficiency of "destroy_constrs" optimization.
  1373   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1374     record getters.
  1375   - Fixed soundness bug related to higher-order constructors.
  1376   - Fixed soundness bug when "full_descrs" is enabled.
  1377   - Improved precision of set constructs.
  1378   - Added "atoms" option.
  1379   - Added cache to speed up repeated Kodkod invocations on the same
  1380     problems.
  1381   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1382     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1383     "SAT4J_Light".  INCOMPATIBILITY.
  1384   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1385     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1386   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1387 
  1388 * Method "induct" now takes instantiations of the form t, where t is not
  1389   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1390   If this is not intended, t has to be enclosed in parentheses.
  1391   By default, the equalities generated by definitional instantiations
  1392   are pre-simplified, which may cause parameters of inductive cases
  1393   to disappear, or may even delete some of the inductive cases.
  1394   Use "induct (no_simp)" instead of "induct" to restore the old
  1395   behaviour. The (no_simp) option is also understood by the "cases"
  1396   and "nominal_induct" methods, which now perform pre-simplification, too.
  1397   INCOMPATIBILITY.
  1398 
  1399 
  1400 *** HOLCF ***
  1401 
  1402 * Variable names in lemmas generated by the domain package have
  1403 changed; the naming scheme is now consistent with the HOL datatype
  1404 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1405 
  1406 * The domain package no longer defines the function "foo_copy" for
  1407 recursive domain "foo".  The reach lemma is now stated directly in
  1408 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1409 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1410 
  1411 * Most definedness lemmas generated by the domain package (previously
  1412 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1413 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1414 Proofs that used definedness lemmas as intro rules may break,
  1415 potential INCOMPATIBILITY.
  1416 
  1417 * Induction and casedist rules generated by the domain package now
  1418 declare proper case_names (one called "bottom", and one named for each
  1419 constructor).  INCOMPATIBILITY.
  1420 
  1421 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1422 rules are generated for each domain, INCOMPATIBILITY.
  1423 
  1424   foo_bar.reach       ~> foo.reach  bar.reach
  1425   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1426 
  1427 * Some lemmas generated by the domain package have been renamed for
  1428 consistency with the datatype package, INCOMPATIBILITY.
  1429 
  1430   foo.ind        ~> foo.induct
  1431   foo.finite_ind ~> foo.finite_induct
  1432   foo.coind      ~> foo.coinduct
  1433   foo.casedist   ~> foo.exhaust
  1434   foo.exhaust    ~> foo.nchotomy
  1435 
  1436 * For consistency with other definition packages, the fixrec package
  1437 now generates qualified theorem names, INCOMPATIBILITY.
  1438 
  1439   foo_simps  ~> foo.simps
  1440   foo_unfold ~> foo.unfold
  1441   foo_induct ~> foo.induct
  1442 
  1443 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1444 method and internal fixrec proofs now use the default simpset instead.
  1445 INCOMPATIBILITY.
  1446 
  1447 * The "contlub" predicate has been removed.  Proof scripts should use
  1448 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1449 
  1450 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1451 
  1452 * The constants cpair, cfst, and csnd have been removed in favor of
  1453 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1454 
  1455 
  1456 *** ML ***
  1457 
  1458 * Antiquotations for basic formal entities:
  1459 
  1460     @{class NAME}         -- type class
  1461     @{class_syntax NAME}  -- syntax representation of the above
  1462 
  1463     @{type_name NAME}     -- logical type
  1464     @{type_abbrev NAME}   -- type abbreviation
  1465     @{nonterminal NAME}   -- type of concrete syntactic category
  1466     @{type_syntax NAME}   -- syntax representation of any of the above
  1467 
  1468     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1469     @{const_abbrev NAME}  -- abbreviated constant
  1470     @{const_syntax NAME}  -- syntax representation of any of the above
  1471 
  1472 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1473 syntax constant (cf. 'syntax' command).
  1474 
  1475 * Antiquotation @{make_string} inlines a function to print arbitrary
  1476 values similar to the ML toplevel.  The result is compiler dependent
  1477 and may fall back on "?" in certain situations.
  1478 
  1479 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1480 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1481 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1482 not work with the asynchronous Isar document model.
  1483 
  1484 * Configuration options now admit dynamic default values, depending on
  1485 the context or even global references.
  1486 
  1487 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1488 uses an efficient external library if available (for Poly/ML).
  1489 
  1490 * Renamed some important ML structures, while keeping the old names
  1491 for some time as aliases within the structure Legacy:
  1492 
  1493   OuterKeyword  ~>  Keyword
  1494   OuterLex      ~>  Token
  1495   OuterParse    ~>  Parse
  1496   OuterSyntax   ~>  Outer_Syntax
  1497   PrintMode     ~>  Print_Mode
  1498   SpecParse     ~>  Parse_Spec
  1499   ThyInfo       ~>  Thy_Info
  1500   ThyLoad       ~>  Thy_Load
  1501   ThyOutput     ~>  Thy_Output
  1502   TypeInfer     ~>  Type_Infer
  1503 
  1504 Note that "open Legacy" simplifies porting of sources, but forgetting
  1505 to remove it again will complicate porting again in the future.
  1506 
  1507 * Most operations that refer to a global context are named
  1508 accordingly, e.g. Simplifier.global_context or
  1509 ProofContext.init_global.  There are some situations where a global
  1510 context actually works, but under normal circumstances one needs to
  1511 pass the proper local context through the code!
  1512 
  1513 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1514 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1515 Pretty.pp argument to merge, which is absent in the standard
  1516 Theory_Data version.
  1517 
  1518 * Sorts.certify_sort and derived "cert" operations for types and terms
  1519 no longer minimize sorts.  Thus certification at the boundary of the
  1520 inference kernel becomes invariant under addition of class relations,
  1521 which is an important monotonicity principle.  Sorts are now minimized
  1522 in the syntax layer only, at the boundary between the end-user and the
  1523 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1524 explicitly in rare situations.
  1525 
  1526 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1527 emphasize that this is in no way a standard operation.
  1528 INCOMPATIBILITY.
  1529 
  1530 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1531 usual for resolution.  Rare INCOMPATIBILITY.
  1532 
  1533 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1534 to emphasize that these only work in a global situation (which is
  1535 quite rare).
  1536 
  1537 * Curried take and drop in library.ML; negative length is interpreted
  1538 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1539 
  1540 * Proof terms: type substitutions on proof constants now use canonical
  1541 order of type variables.  INCOMPATIBILITY for tools working with proof
  1542 terms.
  1543 
  1544 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1545 may no longer carry premises.  User-level specifications are
  1546 transformed accordingly by Thm.add_axiom/add_def.
  1547 
  1548 
  1549 *** System ***
  1550 
  1551 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1552 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1553 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1554 
  1555 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1556 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1557 respectively.
  1558 
  1559 * Old lib/scripts/polyml-platform is superseded by the
  1560 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1561 variant, even on a 64 bit machine.  The following example setting
  1562 prefers 64 bit if available:
  1563 
  1564   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1565 
  1566 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1567 Isabelle/Scala layer for advanced prover interaction and integration.
  1568 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1569 component.
  1570 
  1571 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1572 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1573 similar to the default assignment of the document preparation system
  1574 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1575 provides some operations for direct access to the font without asking
  1576 the user for manual installation.
  1577 
  1578 
  1579 
  1580 New in Isabelle2009-1 (December 2009)
  1581 -------------------------------------
  1582 
  1583 *** General ***
  1584 
  1585 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1586 one backslash should be used, even in ML sources.
  1587 
  1588 
  1589 *** Pure ***
  1590 
  1591 * Locale interpretation propagates mixins along the locale hierarchy.
  1592 The currently only available mixins are the equations used to map
  1593 local definitions to terms of the target domain of an interpretation.
  1594 
  1595 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1596 loc" to print all interpretations of locale "loc" in the theory.
  1597 Interpretations in proofs are not shown.
  1598 
  1599 * Thoroughly revised locales tutorial.  New section on conditional
  1600 interpretation.
  1601 
  1602 * On instantiation of classes, remaining undefined class parameters
  1603 are formally declared.  INCOMPATIBILITY.
  1604 
  1605 
  1606 *** Document preparation ***
  1607 
  1608 * New generalized style concept for printing terms: @{foo (style) ...}
  1609 instead of @{foo_style style ...}  (old form is still retained for
  1610 backward compatibility).  Styles can be also applied for
  1611 antiquotations prop, term_type and typeof.
  1612 
  1613 
  1614 *** HOL ***
  1615 
  1616 * New proof method "smt" for a combination of first-order logic with
  1617 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1618 fixed-size bitvectors; there is also basic support for higher-order
  1619 features (esp. lambda abstractions).  It is an incomplete decision
  1620 procedure based on external SMT solvers using the oracle mechanism;
  1621 for the SMT solver Z3, this method is proof-producing.  Certificates
  1622 are provided to avoid calling the external solvers solely for
  1623 re-checking proofs.  Due to a remote SMT service there is no need for
  1624 installing SMT solvers locally.  See src/HOL/SMT.
  1625 
  1626 * New commands to load and prove verification conditions generated by
  1627 the Boogie program verifier or derived systems (e.g. the Verifying C
  1628 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1629 
  1630 * New counterexample generator tool 'nitpick' based on the Kodkod
  1631 relational model finder.  See src/HOL/Tools/Nitpick and
  1632 src/HOL/Nitpick_Examples.
  1633 
  1634 * New commands 'code_pred' and 'values' to invoke the predicate
  1635 compiler and to enumerate values of inductive predicates.
  1636 
  1637 * A tabled implementation of the reflexive transitive closure.
  1638 
  1639 * New implementation of quickcheck uses generic code generator;
  1640 default generators are provided for all suitable HOL types, records
  1641 and datatypes.  Old quickcheck can be re-activated importing theory
  1642 Library/SML_Quickcheck.
  1643 
  1644 * New testing tool Mirabelle for automated proof tools.  Applies
  1645 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1646 every proof step in a theory.  To be used in batch mode via the
  1647 "mirabelle" utility.
  1648 
  1649 * New proof method "sos" (sum of squares) for nonlinear real
  1650 arithmetic (originally due to John Harison). It requires theory
  1651 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1652 works well in practice on quantifier-free real arithmetic with +, -,
  1653 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1654 inequalities between polynomials.  It makes use of external
  1655 semidefinite programming solvers.  Method "sos" generates a
  1656 certificate that can be pasted into the proof thus avoiding the need
  1657 to call an external tool every time the proof is checked.  See
  1658 src/HOL/Library/Sum_Of_Squares.
  1659 
  1660 * New method "linarith" invokes existing linear arithmetic decision
  1661 procedure only.
  1662 
  1663 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1664 
  1665 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1666 Causes full type information to be output to the ATPs.  This slows
  1667 ATPs down considerably but eliminates a source of unsound "proofs"
  1668 that fail later.
  1669 
  1670 * New method "metisFT": A version of metis that uses full type
  1671 information in order to avoid failures of proof reconstruction.
  1672 
  1673 * New evaluator "approximate" approximates an real valued term using
  1674 the same method as the approximation method.
  1675 
  1676 * Method "approximate" now supports arithmetic expressions as
  1677 boundaries of intervals and implements interval splitting and Taylor
  1678 series expansion.
  1679 
  1680 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1681 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1682 
  1683 * New theory SupInf of the supremum and infimum operators for sets of
  1684 reals.
  1685 
  1686 * New theory Probability, which contains a development of measure
  1687 theory, eventually leading to Lebesgue integration and probability.
  1688 
  1689 * Extended Multivariate Analysis to include derivation and Brouwer's
  1690 fixpoint theorem.
  1691 
  1692 * Reorganization of number theory, INCOMPATIBILITY:
  1693   - new number theory development for nat and int, in theories Divides
  1694     and GCD as well as in new session Number_Theory
  1695   - some constants and facts now suffixed with _nat and _int
  1696     accordingly
  1697   - former session NumberTheory now named Old_Number_Theory, including
  1698     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1699   - moved theory Pocklington from src/HOL/Library to
  1700     src/HOL/Old_Number_Theory
  1701 
  1702 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1703 lcm of finite and infinite sets. It is shown that they form a complete
  1704 lattice.
  1705 
  1706 * Class semiring_div requires superclass no_zero_divisors and proof of
  1707 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1708 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1709 generalized to class semiring_div, subsuming former theorems
  1710 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1711 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1712 INCOMPATIBILITY.
  1713 
  1714 * Refinements to lattice classes and sets:
  1715   - less default intro/elim rules in locale variant, more default
  1716     intro/elim rules in class variant: more uniformity
  1717   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1718     le_inf_iff
  1719   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1720     sup_aci)
  1721   - renamed ACI to inf_sup_aci
  1722   - new class "boolean_algebra"
  1723   - class "complete_lattice" moved to separate theory
  1724     "Complete_Lattice"; corresponding constants (and abbreviations)
  1725     renamed and with authentic syntax:
  1726     Set.Inf ~>    Complete_Lattice.Inf
  1727     Set.Sup ~>    Complete_Lattice.Sup
  1728     Set.INFI ~>   Complete_Lattice.INFI
  1729     Set.SUPR ~>   Complete_Lattice.SUPR
  1730     Set.Inter ~>  Complete_Lattice.Inter
  1731     Set.Union ~>  Complete_Lattice.Union
  1732     Set.INTER ~>  Complete_Lattice.INTER
  1733     Set.UNION ~>  Complete_Lattice.UNION
  1734   - authentic syntax for
  1735     Set.Pow
  1736     Set.image
  1737   - mere abbreviations:
  1738     Set.empty               (for bot)
  1739     Set.UNIV                (for top)
  1740     Set.inter               (for inf, formerly Set.Int)
  1741     Set.union               (for sup, formerly Set.Un)
  1742     Complete_Lattice.Inter  (for Inf)
  1743     Complete_Lattice.Union  (for Sup)
  1744     Complete_Lattice.INTER  (for INFI)
  1745     Complete_Lattice.UNION  (for SUPR)
  1746   - object-logic definitions as far as appropriate
  1747 
  1748 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1749 Un_subset_iff are explicitly deleted as default simp rules; then also
  1750 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1751 deleted to achieve the desired effect.
  1752 
  1753 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1754 rules by default any longer; the same applies to min_max.inf_absorb1
  1755 etc.  INCOMPATIBILITY.
  1756 
  1757 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1758 pred_set_conv by default.  INCOMPATIBILITY.
  1759 
  1760 * Power operations on relations and functions are now one dedicated
  1761 constant "compow" with infix syntax "^^".  Power operation on
  1762 multiplicative monoids retains syntax "^" and is now defined generic
  1763 in class power.  INCOMPATIBILITY.
  1764 
  1765 * Relation composition "R O S" now has a more standard argument order:
  1766 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1767 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1768 break, since the O_assoc rule was not rewritten like this.  Fix using
  1769 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1770 
  1771 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1772 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1773 INCOMPATIBILITY.
  1774 
  1775 * Most rules produced by inductive and datatype package have mandatory
  1776 prefixes.  INCOMPATIBILITY.
  1777 
  1778 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1779 the attribute of the same name.  Each of the theorems in the list
  1780 DERIV_intros assumes composition with an additional function and
  1781 matches a variable to the derivative, which has to be solved by the
  1782 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1783 of most elementary terms.  Former Maclauren.DERIV_tac and
  1784 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1785 INCOMPATIBILITY.
  1786 
  1787 * Code generator attributes follow the usual underscore convention:
  1788     code_unfold     replaces    code unfold
  1789     code_post       replaces    code post
  1790     etc.
  1791   INCOMPATIBILITY.
  1792 
  1793 * Renamed methods:
  1794     sizechange -> size_change
  1795     induct_scheme -> induction_schema
  1796   INCOMPATIBILITY.
  1797 
  1798 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1799 INCOMPATIBILITY, use "undefined" directly.
  1800 
  1801 * Renamed theorems:
  1802     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1803     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1804     Suc_plus1 -> Suc_eq_plus1
  1805     *anti_sym -> *antisym*
  1806     vector_less_eq_def -> vector_le_def
  1807   INCOMPATIBILITY.
  1808 
  1809 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1810 INCOMPATIBILITY.
  1811 
  1812 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1813 INCOMPATIBILITY.
  1814 
  1815 
  1816 *** HOLCF ***
  1817 
  1818 * Theory Representable defines a class "rep" of domains that are
  1819 representable (via an ep-pair) in the universal domain type "udom".
  1820 Instances are provided for all type constructors defined in HOLCF.
  1821 
  1822 * The 'new_domain' command is a purely definitional version of the
  1823 domain package, for representable domains.  Syntax is identical to the
  1824 old domain package.  The 'new_domain' package also supports indirect
  1825 recursion using previously-defined type constructors.  See
  1826 src/HOLCF/ex/New_Domain.thy for examples.
  1827 
  1828 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1829 on the left-hand side of an equation, and then performs
  1830 simplification.  Rewriting is done using rules declared with the
  1831 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1832 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1833 
  1834 * The pattern-match compiler in 'fixrec' can now handle constructors
  1835 with HOL function types.  Pattern-match combinators for the Pair
  1836 constructor are pre-configured.
  1837 
  1838 * The 'fixrec' package now produces better fixed-point induction rules
  1839 for mutually-recursive definitions:  Induction rules have conclusions
  1840 of the form "P foo bar" instead of "P <foo, bar>".
  1841 
  1842 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1843 been renamed to "below".  The name "below" now replaces "less" in many
  1844 theorem names.  (Legacy theorem names using "less" are still supported
  1845 as well.)
  1846 
  1847 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1848 patterns can be used to generate strictness rules, or to make
  1849 functions more strict (much like the bang-patterns supported by the
  1850 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1851 examples.
  1852 
  1853 
  1854 *** ML ***
  1855 
  1856 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1857 errors and run-time exceptions, including detailed source positions.
  1858 
  1859 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1860 identified entries, with some additional information such as source
  1861 position, logical grouping etc.
  1862 
  1863 * Theory and context data is now introduced by the simplified and
  1864 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1865 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1866 copy operation) is still available for some time.
  1867 
  1868 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1869 provides a high-level programming interface to synchronized state
  1870 variables with atomic update.  This works via pure function
  1871 application within a critical section -- its runtime should be as
  1872 short as possible; beware of deadlocks if critical code is nested,
  1873 either directly or indirectly via other synchronized variables!
  1874 
  1875 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1876 wraps raw ML references, explicitly indicating their non-thread-safe
  1877 behaviour.  The Isar toplevel keeps this structure open, to
  1878 accommodate Proof General as well as quick and dirty interactive
  1879 experiments with references.
  1880 
  1881 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1882 parallel tactical reasoning.
  1883 
  1884 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1885 are similar to SUBPROOF, but are slightly more flexible: only the
  1886 specified parts of the subgoal are imported into the context, and the
  1887 body tactic may introduce new subgoals and schematic variables.
  1888 
  1889 * Old tactical METAHYPS, which does not observe the proof context, has
  1890 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1891 or Subgoal.FOCUS etc.
  1892 
  1893 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1894 functors have their own ML name space there is no point to mark them
  1895 separately.)  Minor INCOMPATIBILITY.
  1896 
  1897 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1898 
  1899 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1900 INCOMPATIBILITY.
  1901 
  1902 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1903 mode, which avoids critical setmp.
  1904 
  1905 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1906 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1907 Attrib/Method.setup introduced in Isabelle2009.
  1908 
  1909 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1910 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1911 last resort.  INCOMPATIBILITY.
  1912 
  1913 * Display.pretty_thm now requires a proper context (cf. former
  1914 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1915 or even Display.pretty_thm_without_context as last resort.
  1916 INCOMPATIBILITY.
  1917 
  1918 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1919 Syntax.pretty_typ/term directly, preferably with proper context
  1920 instead of global theory.
  1921 
  1922 
  1923 *** System ***
  1924 
  1925 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1926 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1927 usedir option -q.
  1928 
  1929 * Support for additional "Isabelle components" via etc/components, see
  1930 also the system manual.
  1931 
  1932 * The isabelle makeall tool now operates on all components with
  1933 IsaMakefile, not just hardwired "logics".
  1934 
  1935 * Removed "compress" option from isabelle-process and isabelle usedir;
  1936 this is always enabled.
  1937 
  1938 * Discontinued support for Poly/ML 4.x versions.
  1939 
  1940 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1941 on a given logic image.  This requires the lighttpd webserver and is
  1942 currently supported on Linux only.
  1943 
  1944 
  1945 
  1946 New in Isabelle2009 (April 2009)
  1947 --------------------------------
  1948 
  1949 *** General ***
  1950 
  1951 * Simplified main Isabelle executables, with less surprises on
  1952 case-insensitive file-systems (such as Mac OS).
  1953 
  1954   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1955     "isatool."
  1956 
  1957   - The former "isabelle" alias for "isabelle-process" has been
  1958     removed (should rarely occur to regular users).
  1959 
  1960   - The former "isabelle-interface" and its alias "Isabelle" have been
  1961     removed (interfaces are now regular Isabelle tools).
  1962 
  1963 Within scripts and make files, the Isabelle environment variables
  1964 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1965 respectively.  (The latter are still available as legacy feature.)
  1966 
  1967 The old isabelle-interface wrapper could react in confusing ways if
  1968 the interface was uninstalled or changed otherwise.  Individual
  1969 interface tool configuration is now more explicit, see also the
  1970 Isabelle system manual.  In particular, Proof General is now available
  1971 via "isabelle emacs".
  1972 
  1973 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1974 purge installed copies of Isabelle executables and re-run "isabelle
  1975 install -p ...", or use symlinks.
  1976 
  1977 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1978 old ~/isabelle, which was slightly non-standard and apt to cause
  1979 surprises on case-insensitive file-systems (such as Mac OS).
  1980 
  1981 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1982 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1983 care is required when using older releases of Isabelle.  Note that
  1984 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1985 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1986 
  1987 * Proofs of fully specified statements are run in parallel on
  1988 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1989 a regular 4-core machine, if the initial heap space is made reasonably
  1990 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1991 
  1992 * The main reference manuals ("isar-ref", "implementation", and
  1993 "system") have been updated and extended.  Formally checked references
  1994 as hyperlinks are now available uniformly.
  1995 
  1996 
  1997 *** Pure ***
  1998 
  1999 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2000 respects.  The most important changes are listed below.  See the
  2001 Tutorial on Locales ("locales" manual) for details.
  2002 
  2003 - In locale expressions, instantiation replaces renaming.  Parameters
  2004 must be declared in a for clause.  To aid compatibility with previous
  2005 parameter inheritance, in locale declarations, parameters that are not
  2006 'touched' (instantiation position "_" or omitted) are implicitly added
  2007 with their syntax at the beginning of the for clause.
  2008 
  2009 - Syntax from abbreviations and definitions in locales is available in
  2010 locale expressions and context elements.  The latter is particularly
  2011 useful in locale declarations.
  2012 
  2013 - More flexible mechanisms to qualify names generated by locale
  2014 expressions.  Qualifiers (prefixes) may be specified in locale
  2015 expressions, and can be marked as mandatory (syntax: "name!:") or
  2016 optional (syntax "name?:").  The default depends for plain "name:"
  2017 depends on the situation where a locale expression is used: in
  2018 commands 'locale' and 'sublocale' prefixes are optional, in
  2019 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2020 implicit qualifiers derived from the parameter names of a locale are
  2021 no longer generated.
  2022 
  2023 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2024 instantiation clause in "interpretation" and "interpret" (square
  2025 brackets) is no longer available.  Use locale expressions.
  2026 
  2027 - When converting proof scripts, mandatory qualifiers in
  2028 'interpretation' and 'interpret' should be retained by default, even
  2029 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2030 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2031 in locale expressions range over a single locale instance only.
  2032 
  2033 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2034 In existing theorem specifications replace the includes element by the
  2035 respective context elements of the included locale, omitting those
  2036 that are already present in the theorem specification.  Multiple
  2037 assume elements of a locale should be replaced by a single one
  2038 involving the locale predicate.  In the proof body, declarations (most
  2039 notably theorems) may be regained by interpreting the respective
  2040 locales in the proof context as required (command "interpret").
  2041 
  2042 If using "includes" in replacement of a target solely because the
  2043 parameter types in the theorem are not as general as in the target,
  2044 consider declaring a new locale with additional type constraints on
  2045 the parameters (context element "constrains").
  2046 
  2047 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2048 
  2049 - Locale interpretation commands no longer attempt to simplify goal.
  2050 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2051 methods intro_locales and unfold_locales to clarify.
  2052 
  2053 - Locale interpretation commands no longer accept interpretation
  2054 attributes.  INCOMPATIBILITY.
  2055 
  2056 * Class declaration: so-called "base sort" must not be given in import
  2057 list any longer, but is inferred from the specification.  Particularly
  2058 in HOL, write
  2059 
  2060     class foo = ...
  2061 
  2062 instead of
  2063 
  2064     class foo = type + ...
  2065 
  2066 * Class target: global versions of theorems stemming do not carry a
  2067 parameter prefix any longer.  INCOMPATIBILITY.
  2068 
  2069 * Class 'instance' command no longer accepts attached definitions.
  2070 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2071 
  2072 * Recovered hiding of consts, which was accidentally broken in
  2073 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2074 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2075 
  2076 * Slightly more coherent Pure syntax, with updated documentation in
  2077 isar-ref manual.  Removed locales meta_term_syntax and
  2078 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2079 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2080 directly in regular applications.
  2081 
  2082 * There is a new syntactic category "float_const" for signed decimal
  2083 fractions (e.g. 123.45 or -123.45).
  2084 
  2085 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2086 interface with 'setup' command instead.
  2087 
  2088 * Command 'local_setup' is similar to 'setup', but operates on a local
  2089 theory context.
  2090 
  2091 * The 'axiomatization' command now only works within a global theory
  2092 context.  INCOMPATIBILITY.
  2093 
  2094 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2095 hypotheses.  Sorts required in the course of reasoning need to be
  2096 covered by the constraints in the initial statement, completed by the
  2097 type instance information of the background theory.  Non-trivial sort
  2098 hypotheses, which rarely occur in practice, may be specified via
  2099 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2100 
  2101   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2102 
  2103 The result contains an implicit sort hypotheses as before --
  2104 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2105 normalization.
  2106 
  2107 * Generalized Isar history, with support for linear undo, direct state
  2108 addressing etc.
  2109 
  2110 * Changed defaults for unify configuration options:
  2111 
  2112   unify_trace_bound = 50 (formerly 25)
  2113   unify_search_bound = 60 (formerly 30)
  2114 
  2115 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2116 
  2117   a) On theory merge, the last set of code equations for a particular
  2118      constant is taken (in accordance with the policy applied by other
  2119      parts of the code generator framework).
  2120 
  2121   b) Code equations stemming from explicit declarations (e.g. code
  2122      attribute) gain priority over default code equations stemming
  2123      from definition, primrec, fun etc.
  2124 
  2125 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2126 
  2127 * Unified theorem tables for both code generators.  Thus [code
  2128 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2129 
  2130 * Command 'find_consts' searches for constants based on type and name
  2131 patterns, e.g.
  2132 
  2133     find_consts "_ => bool"
  2134 
  2135 By default, matching is against subtypes, but it may be restricted to
  2136 the whole type.  Searching by name is possible.  Multiple queries are
  2137 conjunctive and queries may be negated by prefixing them with a
  2138 hyphen:
  2139 
  2140     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2141 
  2142 * New 'find_theorems' criterion "solves" matches theorems that
  2143 directly solve the current goal (modulo higher-order unification).
  2144 
  2145 * Auto solve feature for main theorem statements: whenever a new goal
  2146 is stated, "find_theorems solves" is called; any theorems that could
  2147 solve the lemma directly are listed as part of the goal state.
  2148 Cf. associated options in Proof General Isabelle settings menu,
  2149 enabled by default, with reasonable timeout for pathological cases of
  2150 higher-order unification.
  2151 
  2152 
  2153 *** Document preparation ***
  2154 
  2155 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2156 demanding keyword 'by' and supporting the full method expression
  2157 syntax just like the Isar command 'by'.
  2158 
  2159 
  2160 *** HOL ***
  2161 
  2162 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2163 points Main and Complex_Main remain as before.
  2164 
  2165 * Logic image HOL-Plain provides a minimal HOL with the most important
  2166 tools available (inductive, datatype, primrec, ...).  This facilitates
  2167 experimentation and tool development.  Note that user applications
  2168 (and library theories) should never refer to anything below theory
  2169 Main, as before.
  2170 
  2171 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2172 experimentation due to shorter build times.
  2173 
  2174 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2175 were previously part of former HOL-Complex.  Entry point Hyperreal
  2176 remains valid, but theories formerly using Complex_Main should now use
  2177 new entry point Hypercomplex.
  2178 
  2179 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2180 Posix processes.  Avoids potentially expensive forking of the ML
  2181 process.  New thread-based implementation also works on non-Unix
  2182 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2183 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2184 commands are covered in the isar-ref manual.
  2185 
  2186 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2187 sledgehammer without local ATP installation (Vampire etc.). Other
  2188 provers may be included via suitable ML wrappers, see also
  2189 src/HOL/ATP_Linkup.thy.
  2190 
  2191 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2192 menu.
  2193 
  2194 * The metis method no longer fails because the theorem is too trivial
  2195 (contains the empty clause).
  2196 
  2197 * The metis method now fails in the usual manner, rather than raising
  2198 an exception, if it determines that it cannot prove the theorem.
  2199 
  2200 * Method "coherent" implements a prover for coherent logic (see also
  2201 src/Tools/coherent.ML).
  2202 
  2203 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2204 "undefined" is the right choice to replace "arbitrary", though
  2205 logically there is no difference.  INCOMPATIBILITY.
  2206 
  2207 * Command "value" now integrates different evaluation mechanisms.  The
  2208 result of the first successful evaluation mechanism is printed.  In
  2209 square brackets a particular named evaluation mechanisms may be
  2210 specified (currently, [SML], [code] or [nbe]).  See further
  2211 src/HOL/ex/Eval_Examples.thy.
  2212 
  2213 * Normalization by evaluation now allows non-leftlinear equations.
  2214 Declare with attribute [code nbe].
  2215 
  2216 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2217 as the structured Isar versions "cases" and "induct", cf. the
  2218 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2219 are now presented as a list of individual projections
  2220 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2221 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2222 rare situations a different rule is selected --- notably nested tuple
  2223 elimination instead of former prod.exhaust: use explicit (case_tac t
  2224 rule: prod.exhaust) here.
  2225 
  2226 * Attributes "cases", "induct", "coinduct" support "del" option.
  2227 
  2228 * Removed fact "case_split_thm", which duplicates "case_split".
  2229 
  2230 * The option datatype has been moved to a new theory Option.  Renamed
  2231 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2232 
  2233 * New predicate "strict_mono" classifies strict functions on partial
  2234 orders.  With strict functions on linear orders, reasoning about
  2235 (in)equalities is facilitated by theorems "strict_mono_eq",
  2236 "strict_mono_less_eq" and "strict_mono_less".
  2237 
  2238 * Some set operations are now proper qualified constants with
  2239 authentic syntax.  INCOMPATIBILITY:
  2240 
  2241     op Int ~>   Set.Int
  2242     op Un ~>    Set.Un
  2243     INTER ~>    Set.INTER
  2244     UNION ~>    Set.UNION
  2245     Inter ~>    Set.Inter
  2246     Union ~>    Set.Union
  2247     {} ~>       Set.empty
  2248     UNIV ~>     Set.UNIV
  2249 
  2250 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2251 theory Set.
  2252 
  2253 * Auxiliary class "itself" has disappeared -- classes without any
  2254 parameter are treated as expected by the 'class' command.
  2255 
  2256 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2257 
  2258 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2259 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2260 
  2261 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2262 method "approximation".  It proves formulas on real values by using
  2263 interval arithmetic.  In the formulas are also the transcendental
  2264 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2265 allowed. For examples see
  2266 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2267 
  2268 * Theory "Reflection" now resides in HOL/Library.
  2269 
  2270 * Entry point to Word library now simply named "Word".
  2271 INCOMPATIBILITY.
  2272 
  2273 * Made source layout more coherent with logical distribution
  2274 structure:
  2275 
  2276     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2277     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2278     src/HOL/Library/GCD.thy ~> src/HOL/
  2279     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2280     src/HOL/Library/Parity.thy ~> src/HOL/
  2281     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2282     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2283     src/HOL/Real/Lubs.thy ~> src/HOL/
  2284     src/HOL/Real/PReal.thy ~> src/HOL/
  2285     src/HOL/Real/Rational.thy ~> src/HOL/
  2286     src/HOL/Real/RComplete.thy ~> src/HOL/
  2287     src/HOL/Real/RealDef.thy ~> src/HOL/
  2288     src/HOL/Real/RealPow.thy ~> src/HOL/
  2289     src/HOL/Real/Real.thy ~> src/HOL/
  2290     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2291     src/HOL/Complex/Complex.thy ~> src/HOL/
  2292     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2293     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2294     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2295     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2296     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2297     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2298     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2299     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2300     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2301     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2302     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2303     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2304     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2305     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2306     src/HOL/Real/Float ~> src/HOL/Library/
  2307     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2308     src/HOL/Real/RealVector.thy ~> src/HOL/
  2309 
  2310     src/HOL/arith_data.ML ~> src/HOL/Tools
  2311     src/HOL/hologic.ML ~> src/HOL/Tools
  2312     src/HOL/simpdata.ML ~> src/HOL/Tools
  2313     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2314     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2315     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2316     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2317     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2318     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2319     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2320 
  2321     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2322     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2323     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2324     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2325     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2326     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2327 
  2328 * If methods "eval" and "evaluation" encounter a structured proof
  2329 state with !!/==>, only the conclusion is evaluated to True (if
  2330 possible), avoiding strange error messages.
  2331 
  2332 * Method "sizechange" automates termination proofs using (a
  2333 modification of) the size-change principle.  Requires SAT solver.  See
  2334 src/HOL/ex/Termination.thy for examples.
  2335 
  2336 * Simplifier: simproc for let expressions now unfolds if bound
  2337 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2338 
  2339 * Method "arith": Linear arithmetic now ignores all inequalities when
  2340 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2341 
  2342 * New attribute "arith" for facts that should always be used
  2343 automatically by arithmetic. It is intended to be used locally in
  2344 proofs, e.g.
  2345 
  2346   assumes [arith]: "x > 0"
  2347 
  2348 Global usage is discouraged because of possible performance impact.
  2349 
  2350 * New classes "top" and "bot" with corresponding operations "top" and
  2351 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2352 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2353 
  2354 * Changed definition lemma "less_fun_def" in order to provide an
  2355 instance for preorders on functions; use lemma "less_le" instead.
  2356 INCOMPATIBILITY.
  2357 
  2358 * Theory Orderings: class "wellorder" moved here, with explicit
  2359 induction rule "less_induct" as assumption.  For instantiation of
  2360 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2361 INCOMPATIBILITY.
  2362 
  2363 * Theory Orderings: added class "preorder" as superclass of "order".
  2364 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2365 etc. slightly changed.  Some theorems named order_class.* now named
  2366 preorder_class.*.
  2367 
  2368 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2369 "diag" to "Id_on".
  2370 
  2371 * Theory Finite_Set: added a new fold combinator of type
  2372 
  2373   ('a => 'b => 'b) => 'b => 'a set => 'b
  2374 
  2375 Occasionally this is more convenient than the old fold combinator
  2376 which is now defined in terms of the new one and renamed to
  2377 fold_image.
  2378 
  2379 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2380 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2381 extended with further lemmas!).  At the moment both still exist but
  2382 the former will disappear at some point.
  2383 
  2384 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2385 class recpower.  Type-specific simp rules for various recpower types
  2386 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2387 
  2388 rat_power_0    -> power_0
  2389 rat_power_Suc  -> power_Suc
  2390 realpow_0      -> power_0
  2391 realpow_Suc    -> power_Suc
  2392 complexpow_0   -> power_0
  2393 complexpow_Suc -> power_Suc
  2394 power_poly_0   -> power_0
  2395 power_poly_Suc -> power_Suc
  2396 
  2397 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2398 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2399 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2400 of lemmas from Divides has been generalized from nat to class
  2401 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2402 renames resulting from duplicate elimination:
  2403 
  2404     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2405     zero_dvd_iff ~>         dvd_0_left_iff
  2406     dvd_0 ~>                dvd_0_right
  2407     DIVISION_BY_ZERO_DIV ~> div_by_0
  2408     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2409     mult_div ~>             div_mult_self2_is_id
  2410     mult_mod ~>             mod_mult_self2_is_0
  2411 
  2412 * Theory IntDiv: removed many lemmas that are instances of class-based
  2413 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2414 rename old lemmas as follows:
  2415 
  2416 dvd_diff               -> nat_dvd_diff
  2417 dvd_zminus_iff         -> dvd_minus_iff
  2418 mod_add1_eq            -> mod_add_eq
  2419 mod_mult1_eq           -> mod_mult_right_eq
  2420 mod_mult1_eq'          -> mod_mult_left_eq
  2421 mod_mult_distrib_mod   -> mod_mult_eq
  2422 nat_mod_add_left_eq    -> mod_add_left_eq
  2423 nat_mod_add_right_eq   -> mod_add_right_eq
  2424 nat_mod_div_trivial    -> mod_div_trivial
  2425 nat_mod_mod_trivial    -> mod_mod_trivial
  2426 zdiv_zadd_self1        -> div_add_self1
  2427 zdiv_zadd_self2        -> div_add_self2
  2428 zdiv_zmult_self1       -> div_mult_self2_is_id
  2429 zdiv_zmult_self2       -> div_mult_self1_is_id
  2430 zdvd_triv_left         -> dvd_triv_left
  2431 zdvd_triv_right        -> dvd_triv_right
  2432 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2433 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2434 zmod_zadd_left_eq      -> mod_add_left_eq
  2435 zmod_zadd_right_eq     -> mod_add_right_eq
  2436 zmod_zadd_self1        -> mod_add_self1
  2437 zmod_zadd_self2        -> mod_add_self2
  2438 zmod_zadd1_eq          -> mod_add_eq
  2439 zmod_zdiff1_eq         -> mod_diff_eq
  2440 zmod_zdvd_zmod         -> mod_mod_cancel
  2441 zmod_zmod_cancel       -> mod_mod_cancel
  2442 zmod_zmult_self1       -> mod_mult_self2_is_0
  2443 zmod_zmult_self2       -> mod_mult_self1_is_0
  2444 zmod_1                 -> mod_by_1
  2445 zdiv_1                 -> div_by_1
  2446 zdvd_abs1              -> abs_dvd_iff
  2447 zdvd_abs2              -> dvd_abs_iff
  2448 zdvd_refl              -> dvd_refl
  2449 zdvd_trans             -> dvd_trans
  2450 zdvd_zadd              -> dvd_add
  2451 zdvd_zdiff             -> dvd_diff
  2452 zdvd_zminus_iff        -> dvd_minus_iff
  2453 zdvd_zminus2_iff       -> minus_dvd_iff
  2454 zdvd_zmultD            -> dvd_mult_right
  2455 zdvd_zmultD2           -> dvd_mult_left
  2456 zdvd_zmult_mono        -> mult_dvd_mono
  2457 zdvd_0_right           -> dvd_0_right
  2458 zdvd_0_left            -> dvd_0_left_iff
  2459 zdvd_1_left            -> one_dvd
  2460 zminus_dvd_iff         -> minus_dvd_iff
  2461 
  2462 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2463 
  2464 * The real numbers offer decimal input syntax: 12.34 is translated
  2465 into 1234/10^2. This translation is not reversed upon output.
  2466 
  2467 * Theory Library/Polynomial defines an abstract type 'a poly of
  2468 univariate polynomials with coefficients of type 'a.  In addition to
  2469 the standard ring operations, it also supports div and mod.  Code
  2470 generation is also supported, using list-style constructors.
  2471 
  2472 * Theory Library/Inner_Product defines a class of real_inner for real
  2473 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2474 => real.  Class real_inner is a subclass of real_normed_vector from
  2475 theory RealVector.
  2476 
  2477 * Theory Library/Product_Vector provides instances for the product
  2478 type 'a * 'b of several classes from RealVector and Inner_Product.
  2479 Definitions of addition, subtraction, scalar multiplication, norms,
  2480 and inner products are included.
  2481 
  2482 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2483 addition to the field operations, numerals and case syntax are also
  2484 supported.
  2485 
  2486 * Theory Library/Diagonalize provides constructive version of Cantor's
  2487 first diagonalization argument.
  2488 
  2489 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2490 zlcm (for int); carried together from various gcd/lcm developements in
  2491 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2492 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2493 may recover tupled syntax as follows:
  2494 
  2495     hide (open) const gcd
  2496     abbreviation gcd where
  2497       "gcd == (%(a, b). GCD.gcd a b)"
  2498     notation (output)
  2499       GCD.gcd ("gcd '(_, _')")
  2500 
  2501 The same works for lcm, zgcd, zlcm.
  2502 
  2503 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2504 instantiations for algebraic structures.  Removed some duplicate
  2505 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2506 
  2507 * ML antiquotation @{code} takes a constant as argument and generates
  2508 corresponding code in background and inserts name of the corresponding
  2509 resulting ML value/function/datatype constructor binding in place.
  2510 All occurrences of @{code} with a single ML block are generated
  2511 simultaneously.  Provides a generic and safe interface for
  2512 instrumentalizing code generation.  See
  2513 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2514 In future you ought to refrain from ad-hoc compiling generated SML
  2515 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2516 cannot refer to constants for which user-defined serializations are
  2517 set.  Refer to the corresponding ML counterpart directly in that
  2518 cases.
  2519 
  2520 * Command 'rep_datatype': instead of theorem names the command now
  2521 takes a list of terms denoting the constructors of the type to be
  2522 represented as datatype.  The characteristic theorems have to be
  2523 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2524 have disappeared in favour of existing ones:
  2525 
  2526     unit_induct                 ~> unit.induct
  2527     prod_induct                 ~> prod.induct
  2528     sum_induct                  ~> sum.induct
  2529     Suc_Suc_eq                  ~> nat.inject
  2530     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2531 
  2532 
  2533 *** HOL-Algebra ***
  2534 
  2535 * New locales for orders and lattices where the equivalence relation
  2536 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2537 locales use a record structure with field eq for the equivalence.
  2538 
  2539 * New theory of factorial domains.
  2540 
  2541 * Units_l_inv and Units_r_inv are now simp rules by default.
  2542 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2543 and/or r_inv will now also require deletion of these lemmas.
  2544 
  2545 * Renamed the following theorems, INCOMPATIBILITY:
  2546 
  2547 UpperD ~> Upper_memD
  2548 LowerD ~> Lower_memD
  2549 least_carrier ~> least_closed
  2550 greatest_carrier ~> greatest_closed
  2551 greatest_Lower_above ~> greatest_Lower_below
  2552 one_zero ~> carrier_one_zero
  2553 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2554 
  2555 
  2556 *** HOL-Nominal ***
  2557 
  2558 * Nominal datatypes can now contain type-variables.
  2559 
  2560 * Commands 'nominal_inductive' and 'equivariance' work with local
  2561 theory targets.
  2562 
  2563 * Nominal primrec can now works with local theory targets and its
  2564 specification syntax now conforms to the general format as seen in
  2565 'inductive' etc.
  2566 
  2567 * Method "perm_simp" honours the standard simplifier attributes
  2568 (no_asm), (no_asm_use) etc.
  2569 
  2570 * The new predicate #* is defined like freshness, except that on the
  2571 left hand side can be a set or list of atoms.
  2572 
  2573 * Experimental command 'nominal_inductive2' derives strong induction
  2574 principles for inductive definitions.  In contrast to
  2575 'nominal_inductive', which can only deal with a fixed number of
  2576 binders, it can deal with arbitrary expressions standing for sets of
  2577 atoms to be avoided.  The only inductive definition we have at the
  2578 moment that needs this generalisation is the typing rule for Lets in
  2579 the algorithm W:
  2580 
  2581  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2582  -----------------------------------------------------------------
  2583          Gamma |- Let x be t1 in t2 : T2
  2584 
  2585 In this rule one wants to avoid all the binders that are introduced by
  2586 "close Gamma T1".  We are looking for other examples where this
  2587 feature might be useful.  Please let us know.
  2588 
  2589 
  2590 *** HOLCF ***
  2591 
  2592 * Reimplemented the simplification procedure for proving continuity
  2593 subgoals.  The new simproc is extensible; users can declare additional
  2594 continuity introduction rules with the attribute [cont2cont].
  2595 
  2596 * The continuity simproc now uses a different introduction rule for
  2597 solving continuity subgoals on terms with lambda abstractions.  In
  2598 some rare cases the new simproc may fail to solve subgoals that the
  2599 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2600 Potential INCOMPATIBILITY.
  2601 
  2602 * Command 'fixrec': specification syntax now conforms to the general
  2603 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2604 examples.  INCOMPATIBILITY.
  2605 
  2606 
  2607 *** ZF ***
  2608 
  2609 * Proof of Zorn's Lemma for partial orders.
  2610 
  2611 
  2612 *** ML ***
  2613 
  2614 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2615 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2616 depends on multithreading, so timouts will not work before Poly/ML
  2617 5.2.1!
  2618 
  2619 * High-level support for concurrent ML programming, see
  2620 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2621 particularly convenient to organize independent functional
  2622 computations.  The concept of "synchronized variables" provides a
  2623 higher-order interface for components with shared state, avoiding the
  2624 delicate details of mutexes and condition variables.  (Requires
  2625 Poly/ML 5.2.1 or later.)
  2626 
  2627 * ML bindings produced via Isar commands are stored within the Isar
  2628 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2629 become thread-safe and work with undo as expected (concerning
  2630 top-level bindings, not side-effects on global references).
  2631 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2632 compiler at runtime; really global bindings need to be given outside a
  2633 theory.  (Requires Poly/ML 5.2 or later.)
  2634 
  2635 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2636 context.  Top-level ML bindings are stored within the proof context in
  2637 a purely sequential fashion, disregarding the nested proof structure.
  2638 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2639 proof.  (Requires Poly/ML 5.2 or later.)
  2640 
  2641 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2642 and Method.setup, as well as Isar commands 'attribute_setup' and
  2643 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2644 existing code accordingly, or use plain 'setup' together with old
  2645 Method.add_method.
  2646 
  2647 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2648 to 'a -> thm, while results are always tagged with an authentic oracle
  2649 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2650 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2651 accordingly.  Note that extra performance may be gained by producing
  2652 the cterm carefully, avoiding slow Thm.cterm_of.
  2653 
  2654 * Simplified interface for defining document antiquotations via
  2655 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2656 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2657 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2658 examples.
  2659 
  2660 * More systematic treatment of long names, abstract name bindings, and
  2661 name space operations.  Basic operations on qualified names have been
  2662 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2663 Long_Name.append.  Old type bstring has been mostly replaced by
  2664 abstract type binding (see structure Binding), which supports precise
  2665 qualification by packages and local theory targets, as well as proper
  2666 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2667 bstring values into Binding.name, or better pass through abstract
  2668 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2669 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2670 
  2671 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2672 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2673 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2674 
  2675 * Disposed old type and term read functions (Sign.read_def_typ,
  2676 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2677 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2678 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2679 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2680 resort for legacy applications.
  2681 
  2682 * Disposed old declarations, tactics, tactic combinators that refer to
  2683 the simpset or claset of an implicit theory (such as Addsimps,
  2684 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2685 embedded ML text, or local_simpset_of with a proper context passed as
  2686 explicit runtime argument.
  2687 
  2688 * Rules and tactics that read instantiations (read_instantiate,
  2689 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2690 context, which is required for parsing and type-checking.  Moreover,
  2691 the variables are specified as plain indexnames, not string encodings
  2692 thereof.  INCOMPATIBILITY.
  2693 
  2694 * Generic Toplevel.add_hook interface allows to analyze the result of
  2695 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2696 for theorem dependency output of transactions resulting in a new
  2697 theory state.
  2698 
  2699 * ML antiquotations: block-structured compilation context indicated by
  2700 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2701 
  2702   @{binding name}                         - basic name binding
  2703   @{let ?pat = term}                      - term abbreviation (HO matching)
  2704   @{note name = fact}                     - fact abbreviation
  2705   @{thm fact}                             - singleton fact (with attributes)
  2706   @{thms fact}                            - general fact (with attributes)
  2707   @{lemma prop by method}                 - singleton goal
  2708   @{lemma prop by meth1 meth2}            - singleton goal
  2709   @{lemma prop1 ... propN by method}      - general goal
  2710   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2711   @{lemma (open) ...}                     - open derivation
  2712 
  2713 
  2714 *** System ***
  2715 
  2716 * The Isabelle "emacs" tool provides a specific interface to invoke
  2717 Proof General / Emacs, with more explicit failure if that is not
  2718 installed (the old isabelle-interface script silently falls back on
  2719 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2720 installation location of the Proof General distribution.
  2721 
  2722 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2723 the Isabelle process into a JVM/Scala application.  See
  2724 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2725 process wrapper has been discontinued.)
  2726 
  2727 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2728 
  2729 * Various status messages (with exact source position information) are
  2730 emitted, if proper markup print mode is enabled.  This allows
  2731 user-interface components to provide detailed feedback on internal
  2732 prover operations.
  2733 
  2734 
  2735 
  2736 New in Isabelle2008 (June 2008)
  2737 -------------------------------
  2738 
  2739 *** General ***
  2740 
  2741 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2742 and updated, with formally checked references as hyperlinks.
  2743 
  2744 * Theory loader: use_thy (and similar operations) no longer set the
  2745 implicit ML context, which was occasionally hard to predict and in
  2746 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2747 provides a proper context already.
  2748 
  2749 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2750 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2751 'use' within a theory file will do the job.
  2752 
  2753 * Name space merge now observes canonical order, i.e. the second space
  2754 is inserted into the first one, while existing entries in the first
  2755 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2756 swap theory imports.
  2757 
  2758 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2759 INCOMPATIBILITY in identifier syntax etc.
  2760 
  2761 * Outer syntax: string tokens no longer admit escaped white space,
  2762 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2763 white space without escapes.
  2764 
  2765 * Outer syntax: string tokens may contain arbitrary character codes
  2766 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2767 "foo_bar".
  2768 
  2769 
  2770 *** Pure ***
  2771 
  2772 * Context-dependent token translations.  Default setup reverts locally
  2773 fixed variables, and adds hilite markup for undeclared frees.
  2774 
  2775 * Unused theorems can be found using the new command 'unused_thms'.
  2776 There are three ways of invoking it:
  2777 
  2778 (1) unused_thms
  2779      Only finds unused theorems in the current theory.
  2780 
  2781 (2) unused_thms thy_1 ... thy_n -
  2782      Finds unused theorems in the current theory and all of its ancestors,
  2783      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2784 
  2785 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2786      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2787      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2788      their ancestors.
  2789 
  2790 In order to increase the readability of the list produced by
  2791 unused_thms, theorems that have been created by a particular instance
  2792 of a theory command such as 'inductive' or 'function' are considered
  2793 to belong to the same "group", meaning that if at least one theorem in
  2794 this group is used, the other theorems in the same group are no longer
  2795 reported as unused.  Moreover, if all theorems in the group are
  2796 unused, only one theorem in the group is displayed.
  2797 
  2798 Note that proof objects have to be switched on in order for
  2799 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2800 usually the case when using Proof General with the default settings).
  2801 
  2802 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2803 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2804 duplicate fact bindings, or even accidental fact duplications.  Note
  2805 that tools may maintain dynamically scoped facts systematically, using
  2806 PureThy.add_thms_dynamic.
  2807 
  2808 * Command 'hide' now allows to hide from "fact" name space as well.
  2809 
  2810 * Eliminated destructive theorem database, simpset, claset, and
  2811 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2812 update of theories within ML code.
  2813 
  2814 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2815 INCOMPATIBILITY, object-logics depending on former Pure require
  2816 additional setup PureThy.old_appl_syntax_setup; object-logics
  2817 depending on former CPure need to refer to Pure.
  2818 
  2819 * Commands 'use' and 'ML' are now purely functional, operating on
  2820 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2821 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2822 INCOMPATIBILITY.
  2823 
  2824 * Command 'setup': discontinued implicit version with ML reference.
  2825 
  2826 * Instantiation target allows for simultaneous specification of class
  2827 instance operations together with an instantiation proof.
  2828 Type-checking phase allows to refer to class operations uniformly.
  2829 See src/HOL/Complex/Complex.thy for an Isar example and
  2830 src/HOL/Library/Eval.thy for an ML example.
  2831 
  2832 * Indexing of literal facts: be more serious about including only
  2833 facts from the visible specification/proof context, but not the
  2834 background context (locale etc.).  Affects `prop` notation and method
  2835 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2836 situations.
  2837 
  2838 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2839 "(open)" option, which used to expose internal bound variables to the
  2840 proof text.
  2841 
  2842 * Isar statements: removed obsolete case "rule_context".
  2843 INCOMPATIBILITY, better use explicit fixes/assumes.
  2844 
  2845 * Locale proofs: default proof step now includes 'unfold_locales';
  2846 hence 'proof' without argument may be used to unfold locale
  2847 predicates.
  2848 
  2849 
  2850 *** Document preparation ***
  2851 
  2852 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2853 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2854 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2855 spot); renamed link color from "darkblue" to "linkcolor" (default
  2856 value unchanged, can be redefined via \definecolor); no longer sets
  2857 "a4paper" option (unnecessary or even intrusive).
  2858 
  2859 * Antiquotation @{lemma A method} proves proposition A by the given
  2860 method (either a method name or a method name plus (optional) method
  2861 arguments in parentheses) and prints A just like @{prop A}.
  2862 
  2863 
  2864 *** HOL ***
  2865 
  2866 * New primrec package.  Specification syntax conforms in style to
  2867 definition/function/....  No separate induction rule is provided.  The
  2868 "primrec" command distinguishes old-style and new-style specifications
  2869 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2870 When adjusting theories, beware: constants stemming from new-style
  2871 primrec specifications have authentic syntax.
  2872 
  2873 * Metis prover is now an order of magnitude faster, and also works
  2874 with multithreading.
  2875 
  2876 * Metis: the maximum number of clauses that can be produced from a
  2877 theorem is now given by the attribute max_clauses.  Theorems that
  2878 exceed this number are ignored, with a warning printed.
  2879 
  2880 * Sledgehammer no longer produces structured proofs by default. To
  2881 enable, declare [[sledgehammer_full = true]].  Attributes
  2882 reconstruction_modulus, reconstruction_sorts renamed
  2883 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2884 
  2885 * Method "induct_scheme" derives user-specified induction rules
  2886 from well-founded induction and completeness of patterns. This factors
  2887 out some operations that are done internally by the function package
  2888 and makes them available separately.  See
  2889 src/HOL/ex/Induction_Scheme.thy for examples.
  2890 
  2891 * More flexible generation of measure functions for termination
  2892 proofs: Measure functions can be declared by proving a rule of the
  2893 form "is_measure f" and giving it the [measure_function] attribute.
  2894 The "is_measure" predicate is logically meaningless (always true), and
  2895 just guides the heuristic.  To find suitable measure functions, the
  2896 termination prover sets up the goal "is_measure ?f" of the appropriate
  2897 type and generates all solutions by prolog-style backwards proof using
  2898 the declared rules.
  2899 
  2900 This setup also deals with rules like 
  2901 
  2902   "is_measure f ==> is_measure (list_size f)"
  2903 
  2904 which accommodates nested datatypes that recurse through lists.
  2905 Similar rules are predeclared for products and option types.
  2906 
  2907 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2908 
  2909   INCOMPATIBILITIES:
  2910 
  2911   - Definitions of overloaded constants on sets have to be replaced by
  2912     definitions on => and bool.
  2913 
  2914   - Some definitions of overloaded operators on sets can now be proved
  2915     using the definitions of the operators on => and bool.  Therefore,
  2916     the following theorems have been renamed:
  2917 
  2918       subset_def   -> subset_eq
  2919       psubset_def  -> psubset_eq
  2920       set_diff_def -> set_diff_eq
  2921       Compl_def    -> Compl_eq
  2922       Sup_set_def  -> Sup_set_eq
  2923       Inf_set_def  -> Inf_set_eq
  2924       sup_set_def  -> sup_set_eq
  2925       inf_set_def  -> inf_set_eq
  2926 
  2927   - Due to the incompleteness of the HO unification algorithm, some
  2928     rules such as subst may require manual instantiation, if some of
  2929     the unknowns in the rule is a set.
  2930 
  2931   - Higher order unification and forward proofs:
  2932     The proof pattern
  2933 
  2934       have "P (S::'a set)" <...>
  2935       then have "EX S. P S" ..
  2936 
  2937     no longer works (due to the incompleteness of the HO unification
  2938     algorithm) and must be replaced by the pattern
  2939 
  2940       have "EX S. P S"
  2941       proof
  2942         show "P S" <...>
  2943       qed
  2944 
  2945   - Calculational reasoning with subst (or similar rules):
  2946     The proof pattern
  2947 
  2948       have "P (S::'a set)" <...>
  2949       also have "S = T" <...>
  2950       finally have "P T" .
  2951 
  2952     no longer works (for similar reasons as the previous example) and
  2953     must be replaced by something like
  2954 
  2955       have "P (S::'a set)" <...>
  2956       moreover have "S = T" <...>
  2957       ultimately have "P T" by simp
  2958 
  2959   - Tactics or packages written in ML code:
  2960     Code performing pattern matching on types via
  2961 
  2962       Type ("set", [T]) => ...
  2963 
  2964     must be rewritten. Moreover, functions like strip_type or
  2965     binder_types no longer return the right value when applied to a
  2966     type of the form
  2967 
  2968       T1 => ... => Tn => U => bool
  2969 
  2970     rather than
  2971 
  2972       T1 => ... => Tn => U set
  2973 
  2974 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2975 Wellfounded_Relations to theory Wellfounded.
  2976 
  2977 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2978 
  2979 * Class finite no longer treats UNIV as class parameter.  Use class
  2980 enum from theory Library/Enum instead to achieve a similar effect.
  2981 INCOMPATIBILITY.
  2982 
  2983 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2984 and "Cons".  INCOMPATIBILITY.
  2985 
  2986 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2987 Potential INCOMPATIBILITY.
  2988 
  2989 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2990 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2991 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2992 
  2993 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2994 the same name in theory Orderings:
  2995 
  2996   less_trans
  2997   less_linear
  2998   le_imp_less_or_eq
  2999   le_less_trans
  3000   less_le_trans
  3001   less_not_sym
  3002   less_asym
  3003 
  3004 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3005 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3006 and different variable names.
  3007 
  3008 * Library/Option_ord.thy: Canonical order on option type.
  3009 
  3010 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3011 finite maps.
  3012 
  3013 * Library/Countable.thy: Type class for countable types.
  3014 
  3015 * Theory Int: The representation of numerals has changed.  The infix
  3016 operator BIT and the bit datatype with constructors B0 and B1 have
  3017 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3018 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3019 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3020 accordingly.
  3021 
  3022 * Theory Nat: definition of <= and < on natural numbers no longer
  3023 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3024 le_def and less_def have disappeared.  Consider lemmas not_less
  3025 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3026 
  3027 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3028 (whose purpose mainly is for various fold_set functionals) have been
  3029 abandoned in favor of the existing algebraic classes
  3030 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3031 lower_semilattice (resp. upper_semilattice) and linorder.
  3032 INCOMPATIBILITY.
  3033 
  3034 * Theory Transitive_Closure: induct and cases rules now declare proper
  3035 case_names ("base" and "step").  INCOMPATIBILITY.
  3036 
  3037 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3038 lattices.  The form set-specific version is available as
  3039 Inductive.lfp_ordinal_induct_set.
  3040 
  3041 * Renamed theorems "power.simps" to "power_int.simps".
  3042 INCOMPATIBILITY.
  3043 
  3044 * Class semiring_div provides basic abstract properties of semirings
  3045 with division and modulo operations.  Subsumes former class dvd_mod.
  3046 
  3047 * Merged theories IntDef, Numeral and IntArith into unified theory
  3048 Int.  INCOMPATIBILITY.
  3049 
  3050 * Theory Library/Code_Index: type "index" now represents natural
  3051 numbers rather than integers.  INCOMPATIBILITY.
  3052 
  3053 * New class "uminus" with operation "uminus" (split of from class
  3054 "minus" which now only has operation "minus", binary).
  3055 INCOMPATIBILITY.
  3056 
  3057 * Constants "card", "internal_split", "option_map" now with authentic
  3058 syntax.  INCOMPATIBILITY.
  3059 
  3060 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3061 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3062 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3063 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3064 Sup_set_def, le_def, less_def, option_map_def now with object
  3065 equality.  INCOMPATIBILITY.
  3066 
  3067 * Records. Removed K_record, and replaced it by pure lambda term
  3068 %x. c. The simplifier setup is now more robust against eta expansion.
  3069 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3070 
  3071 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3072 
  3073 * Library/ListVector: new theory of arithmetic vector operations.
  3074 
  3075 * Library/Order_Relation: new theory of various orderings as sets of
  3076 pairs.  Defines preorders, partial orders, linear orders and
  3077 well-orders on sets and on types.
  3078 
  3079 
  3080 *** ZF ***
  3081 
  3082 * Renamed some theories to allow to loading both ZF and HOL in the
  3083 same session:
  3084 
  3085   Datatype  -> Datatype_ZF
  3086   Inductive -> Inductive_ZF
  3087   Int       -> Int_ZF
  3088   IntDiv    -> IntDiv_ZF
  3089   Nat       -> Nat_ZF
  3090   List      -> List_ZF
  3091   Main      -> Main_ZF
  3092 
  3093 INCOMPATIBILITY: ZF theories that import individual theories below
  3094 Main might need to be adapted.  Regular theory Main is still
  3095 available, as trivial extension of Main_ZF.
  3096 
  3097 
  3098 *** ML ***
  3099 
  3100 * ML within Isar: antiquotation @{const name} or @{const
  3101 name(typargs)} produces statically-checked Const term.
  3102 
  3103 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3104 (of the same name).  Removed obsolete print command.
  3105 
  3106 * Removed obsolete "use_legacy_bindings" function.
  3107 
  3108 * The ``print mode'' is now a thread-local value derived from a global
  3109 template (the former print_mode reference), thus access becomes
  3110 non-critical.  The global print_mode reference is for session
  3111 management only; user-code should use print_mode_value,
  3112 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3113 
  3114 * Functions system/system_out provide a robust way to invoke external
  3115 shell commands, with propagation of interrupts (requires Poly/ML
  3116 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3117 
  3118 
  3119 *** System ***
  3120 
  3121 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3122 in accordance with Proof General 3.7, which prefers GNU emacs.
  3123 
  3124 * isatool tty runs Isabelle process with plain tty interaction;
  3125 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3126 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3127 
  3128 * isatool browser now works with Cygwin as well, using general
  3129 "javapath" function defined in Isabelle process environment.
  3130 
  3131 * YXML notation provides a simple and efficient alternative to
  3132 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3133 isatool yxml as described in the Isabelle system manual.
  3134 
  3135 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3136 provides general wrapper for managing an Isabelle process in a robust
  3137 fashion, with ``cooked'' output from stdin/stderr.
  3138 
  3139 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3140 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3141 
  3142 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3143 way of changing the user's settings is via
  3144 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3145 script.
  3146 
  3147 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3148 cores of the underlying machine, which is a good starting point for
  3149 optimal performance tuning.  The corresponding usedir option -M allows
  3150 "max" as an alias for "0".  WARNING: does not work on certain versions
  3151 of Mac OS (with Poly/ML 5.1).
  3152 
  3153 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3154 adverse effect of Isabelle flooding interactive front-ends (notably
  3155 ProofGeneral / XEmacs).
  3156 
  3157 
  3158 
  3159 New in Isabelle2007 (November 2007)
  3160 -----------------------------------
  3161 
  3162 *** General ***
  3163 
  3164 * More uniform information about legacy features, notably a
  3165 warning/error of "Legacy feature: ...", depending on the state of the
  3166 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3167 legacy features will disappear eventually.
  3168 
  3169 * Theory syntax: the header format ``theory A = B + C:'' has been
  3170 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3171 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3172 
  3173 * Theory syntax: the old non-Isar theory file format has been
  3174 discontinued altogether.  Note that ML proof scripts may still be used
  3175 with Isar theories; migration is usually quite simple with the ML
  3176 function use_legacy_bindings.  INCOMPATIBILITY.
  3177 
  3178 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3179 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3180 quotes.
  3181 
  3182 * Theory loader: be more serious about observing the static theory
  3183 header specifications (including optional directories), but not the
  3184 accidental file locations of previously successful loads.  The strict
  3185 update policy of former update_thy is now already performed by
  3186 use_thy, so the former has been removed; use_thys updates several
  3187 theories simultaneously, just as 'imports' within a theory header
  3188 specification, but without merging the results.  Potential
  3189 INCOMPATIBILITY: may need to refine theory headers and commands
  3190 ROOT.ML which depend on load order.
  3191 
  3192 * Theory loader: optional support for content-based file
  3193 identification, instead of the traditional scheme of full physical
  3194 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3195 (cf. the system manual).  The new scheme allows to work with
  3196 non-finished theories in persistent session images, such that source
  3197 files may be moved later on without requiring reloads.
  3198 
  3199 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3200 file (with the same base name as the theory) are considered a legacy
  3201 feature, which will disappear eventually. Even now, the theory loader
  3202 no longer maintains dependencies on such files.
  3203 
  3204 * Syntax: the scope for resolving ambiguities via type-inference is
  3205 now limited to individual terms, instead of whole simultaneous
  3206 specifications as before. This greatly reduces the complexity of the
  3207 syntax module and improves flexibility by separating parsing and
  3208 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3209 'fixes' etc.) are required in rare situations.
  3210 
  3211 * Syntax: constants introduced by new-style packages ('definition',
  3212 'abbreviation' etc.) are passed through the syntax module in
  3213 ``authentic mode''. This means that associated mixfix annotations
  3214 really stick to such constants, independently of potential name space
  3215 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3216 trees are represented slightly differently, may need to adapt syntax
  3217 translations accordingly. Use CONST marker in 'translations' and
  3218 @{const_syntax} antiquotation in 'parse_translation' etc.
  3219 
  3220 * Legacy goal package: reduced interface to the bare minimum required
  3221 to keep existing proof scripts running.  Most other user-level
  3222 functions are now part of the OldGoals structure, which is *not* open
  3223 by default (consider isatool expandshort before open OldGoals).
  3224 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3225 these tend to cause confusion about the actual goal (!) context being
  3226 used here, which is not necessarily the same as the_context().
  3227 
  3228 * Command 'find_theorems': supports "*" wild-card in "name:"
  3229 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3230 support a specific search form (see ProofGeneral/CHANGES).
  3231 
  3232 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3233 by default, which means that "prems" (and also "fixed variables") are
  3234 suppressed from proof state output.  Note that the ProofGeneral
  3235 settings mechanism allows to change and save options persistently, but
  3236 older versions of Isabelle will fail to start up if a negative prems
  3237 limit is imposed.
  3238 
  3239 * Local theory targets may be specified by non-nested blocks of
  3240 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3241 contain definitions, theorems etc., including any derived mechanism
  3242 that has been implemented on top of these primitives.  This concept
  3243 generalizes the existing ``theorem (in ...)'' towards more versatility
  3244 and scalability.
  3245 
  3246 * Proof General interface: proper undo of final 'end' command;
  3247 discontinued Isabelle/classic mode (ML proof scripts).
  3248 
  3249 
  3250 *** Document preparation ***
  3251 
  3252 * Added antiquotation @{theory name} which prints the given name,
  3253 after checking that it refers to a valid ancestor theory in the
  3254 current context.
  3255 
  3256 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3257 check the given source text as ML type/structure, printing verbatim.
  3258 
  3259 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3260 "c args == rhs" given in the current context.  (Any number of
  3261 arguments may be given on the LHS.)
  3262 
  3263 
  3264 *** Pure ***
  3265 
  3266 * The 'class' package offers a combination of axclass and locale to
  3267 achieve Haskell-like type classes in Isabelle.  Definitions and
  3268 theorems within a class context produce both relative results (with
  3269 implicit parameters according to the locale context), and polymorphic
  3270 constants with qualified polymorphism (according to the class
  3271 context).  Within the body context of a 'class' target, a separate
  3272 syntax layer ("user space type system") takes care of converting
  3273 between global polymorphic consts and internal locale representation.
  3274 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3275 "isatool doc classes" provides a tutorial.
  3276 
  3277 * Generic code generator framework allows to generate executable
  3278 code for ML and Haskell (including Isabelle classes).  A short usage
  3279 sketch:
  3280 
  3281     internal compilation:
  3282         export_code <list of constants (term syntax)> in SML
  3283     writing SML code to a file:
  3284         export_code <list of constants (term syntax)> in SML <filename>
  3285     writing OCaml code to a file:
  3286         export_code <list of constants (term syntax)> in OCaml <filename>
  3287     writing Haskell code to a bunch of files:
  3288         export_code <list of constants (term syntax)> in Haskell <filename>
  3289 
  3290     evaluating closed propositions to True/False using code generation:
  3291         method ``eval''
  3292 
  3293 Reasonable default setup of framework in HOL.
  3294 
  3295 Theorem attributs for selecting and transforming function equations theorems:
  3296 
  3297     [code fun]:        select a theorem as function equation for a specific constant
  3298     [code fun del]:    deselect a theorem as function equation for a specific constant
  3299     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3300     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3301 
  3302 User-defined serializations (target in {SML, OCaml, Haskell}):
  3303 
  3304     code_const <and-list of constants (term syntax)>
  3305       {(target) <and-list of const target syntax>}+
  3306 
  3307     code_type <and-list of type constructors>
  3308       {(target) <and-list of type target syntax>}+
  3309 
  3310     code_instance <and-list of instances>
  3311       {(target)}+
  3312         where instance ::= <type constructor> :: <class>
  3313 
  3314     code_class <and_list of classes>
  3315       {(target) <and-list of class target syntax>}+
  3316         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3317 
  3318 code_instance and code_class only are effective to target Haskell.
  3319 
  3320 For example usage see src/HOL/ex/Codegenerator.thy and
  3321 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3322 generation from Isabelle/HOL theories is available via "isatool doc
  3323 codegen".
  3324 
  3325 * Code generator: consts in 'consts_code' Isar commands are now
  3326 referred to by usual term syntax (including optional type
  3327 annotations).
  3328 
  3329 * Command 'no_translations' removes translation rules from theory
  3330 syntax.
  3331 
  3332 * Overloaded definitions are now actually checked for acyclic
  3333 dependencies.  The overloading scheme is slightly more general than
  3334 that of Haskell98, although Isabelle does not demand an exact
  3335 correspondence to type class and instance declarations.
  3336 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3337 exotic versions of overloading -- at the discretion of the user!
  3338 
  3339 Polymorphic constants are represented via type arguments, i.e. the
  3340 instantiation that matches an instance against the most general
  3341 declaration given in the signature.  For example, with the declaration
  3342 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3343 as c(nat).  Overloading is essentially simultaneous structural
  3344 recursion over such type arguments.  Incomplete specification patterns
  3345 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3346 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3347 Command 'print_theory' outputs the normalized system of recursive
  3348 equations, see section "definitions".
  3349 
  3350 * Configuration options are maintained within the theory or proof
  3351 context (with name and type bool/int/string), providing a very simple
  3352 interface to a poor-man's version of general context data.  Tools may
  3353 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3354 these values using Config.get etc.  Users may change options via an
  3355 associated attribute of the same name.  This form of context
  3356 declaration works particularly well with commands 'declare' or
  3357 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3358 very easy to avoid global references, which would not observe Isar
  3359 toplevel undo/redo and fail to work with multithreading.
  3360 
  3361 Various global ML references of Pure and HOL have been turned into
  3362 configuration options:
  3363 
  3364   Unify.search_bound		unify_search_bound
  3365   Unify.trace_bound		unify_trace_bound
  3366   Unify.trace_simp		unify_trace_simp
  3367   Unify.trace_types		unify_trace_types
  3368   Simplifier.simp_depth_limit	simp_depth_limit
  3369   Blast.depth_limit		blast_depth_limit
  3370   DatatypeProp.dtK		datatype_distinctness_limit
  3371   fast_arith_neq_limit  	fast_arith_neq_limit
  3372   fast_arith_split_limit	fast_arith_split_limit
  3373 
  3374 * Named collections of theorems may be easily installed as context
  3375 data using the functor NamedThmsFun (see also
  3376 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3377 attributes; there is also a toplevel print command.  This facility is
  3378 just a common case of general context data, which is the preferred way
  3379 for anything more complex than just a list of facts in canonical
  3380 order.
  3381 
  3382 * Isar: command 'declaration' augments a local theory by generic
  3383 declaration functions written in ML.  This enables arbitrary content
  3384 being added to the context, depending on a morphism that tells the
  3385 difference of the original declaration context wrt. the application
  3386 context encountered later on.
  3387 
  3388 * Isar: proper interfaces for simplification procedures.  Command
  3389 'simproc_setup' declares named simprocs (with match patterns, and body
  3390 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3391 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3392 
  3393 * Isar: an extra pair of brackets around attribute declarations
  3394 abbreviates a theorem reference involving an internal dummy fact,
  3395 which will be ignored later --- only the effect of the attribute on
  3396 the background context will persist.  This form of in-place
  3397 declarations is particularly useful with commands like 'declare' and
  3398 'using', for example ``have A using [[simproc a]] by simp''.
  3399 
  3400 * Isar: method "assumption" (and implicit closing of subproofs) now
  3401 takes simple non-atomic goal assumptions into account: after applying
  3402 an assumption as a rule the resulting subgoals are solved by atomic
  3403 assumption steps.  This is particularly useful to finish 'obtain'
  3404 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3405 without referring to the original premise "!!x. P x ==> thesis" in the
  3406 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3407 more permissive.
  3408 
  3409 * Isar: implicit use of prems from the Isar proof context is
  3410 considered a legacy feature.  Common applications like ``have A .''
  3411 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3412 referencing facts explicitly here improves readability and
  3413 maintainability of proof texts.
  3414 
  3415 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3416 the obtained context from the course of reasoning!  For example:
  3417 
  3418   assume "EX x y. A x & B y"   -- "any previous fact"
  3419   then guess x and y by clarify
  3420 
  3421 This technique is potentially adventurous, depending on the facts and
  3422 proof tools being involved here.
  3423 
  3424 * Isar: known facts from the proof context may be specified as literal
  3425 propositions, using ASCII back-quote syntax.  This works wherever
  3426 named facts used to be allowed so far, in proof commands, proof
  3427 methods, attributes etc.  Literal facts are retrieved from the context
  3428 according to unification of type and term parameters.  For example,
  3429 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3430 theorems in the current context, then these are valid literal facts:
  3431 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3432 
  3433 There is also a proof method "fact" which does the same composition
  3434 for explicit goal states, e.g. the following proof texts coincide with
  3435 certain special cases of literal facts:
  3436 
  3437   have "A" by fact                 ==  note `A`
  3438   have "A ==> B" by fact           ==  note `A ==> B`
  3439   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3440   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3441 
  3442 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3443 outer syntax.  Thus symbolic identifiers may be used without
  3444 additional white space in declarations like this: ``assume *: A''.
  3445 
  3446 * Isar: 'print_facts' prints all local facts of the current context,
  3447 both named and unnamed ones.
  3448 
  3449 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3450 
  3451   def x == "t" and y == "u"
  3452 
  3453 * Isar: added command 'unfolding', which is structurally similar to
  3454 'using', but affects both the goal state and facts by unfolding given
  3455 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3456 'unfolded' attribute may be replaced by first-class proof text.
  3457 
  3458 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3459 and command 'unfolding' now all support object-level equalities
  3460 (potentially conditional).  The underlying notion of rewrite rule is
  3461 analogous to the 'rule_format' attribute, but *not* that of the
  3462 Simplifier (which is usually more generous).
  3463 
  3464 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3465 premises of a theorem by n. Useful in conjunction with drule.
  3466 
  3467 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3468 method expression within a sandbox consisting of the first N
  3469 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3470 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3471 simplifies all new goals that emerge from applying rule foo to the
  3472 originally first one.
  3473 
  3474 * Isar: schematic goals are no longer restricted to higher-order
  3475 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3476 expected.
  3477 
  3478 * Isar: the conclusion of a long theorem statement is now either
  3479 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3480 (essentially a disjunction of cases with local parameters and
  3481 assumptions).  The latter allows to express general elimination rules
  3482 adequately; in this notation common elimination rules look like this:
  3483 
  3484   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3485     assumes "EX x. P x"
  3486     obtains x where "P x"
  3487 
  3488   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3489     assumes "A & B"
  3490     obtains A and B
  3491 
  3492   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3493     assumes "A | B"
  3494     obtains
  3495       A
  3496     | B
  3497 
  3498 The subsequent classical rules even refer to the formal "thesis"
  3499 explicitly:
  3500 
  3501   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3502     obtains "~ thesis"
  3503 
  3504   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3505     obtains "thesis ==> something"
  3506 
  3507 The actual proof of an 'obtains' statement is analogous to that of the
  3508 Isar proof element 'obtain', only that there may be several cases.
  3509 Optional case names may be specified in parentheses; these will be
  3510 available both in the present proof and as annotations in the
  3511 resulting rule, for later use with the 'cases' method (cf. attribute
  3512 case_names).
  3513 
  3514 * Isar: the assumptions of a long theorem statement are available as
  3515 "assms" fact in the proof context.  This is more appropriate than the
  3516 (historical) "prems", which refers to all assumptions of the current
  3517 context, including those from the target locale, proof body etc.
  3518 
  3519 * Isar: 'print_statement' prints theorems from the current theory or
  3520 proof context in long statement form, according to the syntax of a
  3521 top-level lemma.
  3522 
  3523 * Isar: 'obtain' takes an optional case name for the local context
  3524 introduction rule (default "that").
  3525 
  3526 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3527 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3528 to occur.
  3529 
  3530 * Pure: syntax "CONST name" produces a fully internalized constant
  3531 according to the current context.  This is particularly useful for
  3532 syntax translations that should refer to internal constant
  3533 representations independently of name spaces.
  3534 
  3535 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3536 instead of "FOO ". This allows multiple binder declarations to coexist
  3537 in the same context.  INCOMPATIBILITY.
  3538 
  3539 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3540 primitive that also works in a locale context (both for constants and
  3541 fixed variables). Type declaration and internal syntactic representation
  3542 of given constants retrieved from the context. Likewise, the
  3543 'no_notation' command allows to remove given syntax annotations from the
  3544 current context.
  3545 
  3546 * Isar/locales: new derived specification elements 'axiomatization',
  3547 'definition', 'abbreviation', which support type-inference, admit
  3548 object-level specifications (equality, equivalence).  See also the
  3549 isar-ref manual.  Examples:
  3550 
  3551   axiomatization
  3552     eq  (infix "===" 50) where
  3553     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3554 
  3555   definition "f x y = x + y + 1"
  3556   definition g where "g x = f x x"
  3557 
  3558   abbreviation
  3559     neq  (infix "=!=" 50) where
  3560     "x =!= y == ~ (x === y)"
  3561 
  3562 These specifications may be also used in a locale context.  Then the
  3563 constants being introduced depend on certain fixed parameters, and the
  3564 constant name is qualified by the locale base name.  An internal
  3565 abbreviation takes care for convenient input and output, making the
  3566 parameters implicit and using the original short name.  See also
  3567 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3568 entities from a monomorphic theory.
  3569 
  3570 Presently, abbreviations are only available 'in' a target locale, but
  3571 not inherited by general import expressions.  Also note that
  3572 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3573 'translations' in common applications.  The "no_abbrevs" print mode
  3574 prevents folding of abbreviations in term output.
  3575 
  3576 Concrete syntax is attached to specified constants in internal form,
  3577 independently of name spaces.  The parse tree representation is
  3578 slightly different -- use 'notation' instead of raw 'syntax', and
  3579 'translations' with explicit "CONST" markup to accommodate this.
  3580 
  3581 * Pure/Isar: unified syntax for new-style specification mechanisms
  3582 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3583 full type inference and dummy patterns ("_").  For example:
  3584 
  3585   definition "K x _ = x"
  3586 
  3587   inductive conj for A B
  3588   where "A ==> B ==> conj A B"
  3589 
  3590 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3591 the current context.  Print mode "no_abbrevs" prevents inversion of
  3592 abbreviations on output.
  3593 
  3594 * Isar/locales: improved parameter handling: use of locales "var" and
  3595 "struct" no longer necessary; - parameter renamings are no longer
  3596 required to be injective.  For example, this allows to define
  3597 endomorphisms as locale endom = homom mult mult h.
  3598 
  3599 * Isar/locales: changed the way locales with predicates are defined.
  3600 Instead of accumulating the specification, the imported expression is
  3601 now an interpretation.  INCOMPATIBILITY: different normal form of
  3602 locale expressions.  In particular, in interpretations of locales with
  3603 predicates, goals repesenting already interpreted fragments are not
  3604 removed automatically.  Use methods `intro_locales' and
  3605 `unfold_locales'; see below.
  3606 
  3607 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3608 provide backward reasoning on locales predicates.  The methods are
  3609 aware of interpretations and discharge corresponding goals.
  3610 `intro_locales' is less aggressive then `unfold_locales' and does not
  3611 unfold predicates to assumptions.
  3612 
  3613 * Isar/locales: the order in which locale fragments are accumulated
  3614 has changed.  This enables to override declarations from fragments due
  3615 to interpretations -- for example, unwanted simp rules.
  3616 
  3617 * Isar/locales: interpretation in theories and proof contexts has been
  3618 extended.  One may now specify (and prove) equations, which are
  3619 unfolded in interpreted theorems.  This is useful for replacing
  3620 defined concepts (constants depending on locale parameters) by
  3621 concepts already existing in the target context.  Example:
  3622 
  3623   interpretation partial_order ["op <= :: [int, int] => bool"]
  3624     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3625 
  3626 Typically, the constant `partial_order.less' is created by a
  3627 definition specification element in the context of locale
  3628 partial_order.
  3629 
  3630 * Method "induct": improved internal context management to support
  3631 local fixes and defines on-the-fly. Thus explicit meta-level
  3632 connectives !!  and ==> are rarely required anymore in inductive goals
  3633 (using object-logic connectives for this purpose has been long
  3634 obsolete anyway). Common proof patterns are explained in
  3635 src/HOL/Induct/Common_Patterns.thy, see also
  3636 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3637 examples.
  3638 
  3639 * Method "induct": improved handling of simultaneous goals. Instead of
  3640 introducing object-level conjunction, the statement is now split into
  3641 several conclusions, while the corresponding symbolic cases are nested
  3642 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3643 see src/HOL/Induct/Common_Patterns.thy, for example.
  3644 
  3645 * Method "induct": mutual induction rules are now specified as a list
  3646 of rule sharing the same induction cases. HOL packages usually provide
  3647 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3648 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3649 mutual induction rules differently, i.e. like this:
  3650 
  3651   (induct rule: foo_bar.inducts)
  3652   (induct set: foo bar)
  3653   (induct pred: foo bar)
  3654   (induct type: foo bar)
  3655 
  3656 The ML function ProjectRule.projections turns old-style rules into the
  3657 new format.
  3658 
  3659 * Method "coinduct": dual of induction, see
  3660 src/HOL/Library/Coinductive_List.thy for various examples.
  3661 
  3662 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3663 considered a legacy feature.
  3664 
  3665 * Attribute "symmetric" produces result with standardized schematic
  3666 variables (index 0).  Potential INCOMPATIBILITY.
  3667 
  3668 * Simplifier: by default the simplifier trace only shows top level
  3669 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3670 default. Thus there is less danger of being flooded by the trace. The
  3671 trace indicates where parts have been suppressed.
  3672   
  3673 * Provers/classical: removed obsolete classical version of elim_format
  3674 attribute; classical elim/dest rules are now treated uniformly when
  3675 manipulating the claset.
  3676 
  3677 * Provers/classical: stricter checks to ensure that supplied intro,
  3678 dest and elim rules are well-formed; dest and elim rules must have at
  3679 least one premise.
  3680 
  3681 * Provers/classical: attributes dest/elim/intro take an optional
  3682 weight argument for the rule (just as the Pure versions).  Weights are
  3683 ignored by automated tools, but determine the search order of single
  3684 rule steps.
  3685 
  3686 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3687 where the body does not mention the bound variable.  Note that dummy
  3688 patterns implicitly depend on their context of bounds, which makes
  3689 "{_. _}" match any set comprehension as expected.  Potential
  3690 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3691 constant "_idtdummy" in the binding position.
  3692 
  3693 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3694 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3695 for example "A -> B" => "Pi A (%_. B)".
  3696 
  3697 * Pure: 'class_deps' command visualizes the subclass relation, using
  3698 the graph browser tool.
  3699 
  3700 * Pure: 'print_theory' now suppresses certain internal declarations by
  3701 default; use '!' option for full details.
  3702 
  3703 
  3704 *** HOL ***
  3705 
  3706 * Method "metis" proves goals by applying the Metis general-purpose
  3707 resolution prover (see also http://gilith.com/software/metis/).
  3708 Examples are in the directory MetisExamples.  WARNING: the
  3709 Isabelle/HOL-Metis integration does not yet work properly with
  3710 multi-threading.
  3711   
  3712 * Command 'sledgehammer' invokes external automatic theorem provers as
  3713 background processes.  It generates calls to the "metis" method if
  3714 successful. These can be pasted into the proof.  Users do not have to
  3715 wait for the automatic provers to return.  WARNING: does not really
  3716 work with multi-threading.
  3717 
  3718 * New "auto_quickcheck" feature tests outermost goal statements for
  3719 potential counter-examples.  Controlled by ML references
  3720 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3721 5000 milliseconds).  Fails silently if statements is outside of
  3722 executable fragment, or any other codgenerator problem occurs.
  3723 
  3724 * New constant "undefined" with axiom "undefined x = undefined".
  3725 
  3726 * Added class "HOL.eq", allowing for code generation with polymorphic
  3727 equality.
  3728 
  3729 * Some renaming of class constants due to canonical name prefixing in
  3730 the new 'class' package:
  3731 
  3732     HOL.abs ~> HOL.abs_class.abs
  3733     HOL.divide ~> HOL.divide_class.divide
  3734     0 ~> HOL.zero_class.zero
  3735     1 ~> HOL.one_class.one
  3736     op + ~> HOL.plus_class.plus
  3737     op - ~> HOL.minus_class.minus
  3738     uminus ~> HOL.minus_class.uminus
  3739     op * ~> HOL.times_class.times
  3740     op < ~> HOL.ord_class.less
  3741     op <= > HOL.ord_class.less_eq
  3742     Nat.power ~> Power.power_class.power
  3743     Nat.size ~> Nat.size_class.size
  3744     Numeral.number_of ~> Numeral.number_class.number_of
  3745     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3746     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3747     Orderings.min ~> Orderings.ord_class.min
  3748     Orderings.max ~> Orderings.ord_class.max
  3749     Divides.op div ~> Divides.div_class.div
  3750     Divides.op mod ~> Divides.div_class.mod
  3751     Divides.op dvd ~> Divides.div_class.dvd
  3752 
  3753 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3754 
  3755 a) User-defined constants using any of the names "plus", "minus",
  3756 "times", "less" or "less_eq". The standard syntax translations for
  3757 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3758 names.
  3759 
  3760 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3761 INCOMPATIBILITY: use more specific names.
  3762 
  3763 c) Permutative equations (e.g. "a + b = b + a")
  3764 Since the change of names also changes the order of terms, permutative
  3765 rewrite rules may get applied in a different order. Experience shows
  3766 that this is rarely the case (only two adaptions in the whole Isabelle
  3767 distribution).  INCOMPATIBILITY: rewrite proofs
  3768 
  3769 d) ML code directly refering to constant names
  3770 This in general only affects hand-written proof tactics, simprocs and
  3771 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3772 Consider using @{const_name} antiquotation.
  3773 
  3774 * New class "default" with associated constant "default".
  3775 
  3776 * Function "sgn" is now overloaded and available on int, real, complex
  3777 (and other numeric types), using class "sgn".  Two possible defs of
  3778 sgn are given as equational assumptions in the classes sgn_if and
  3779 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3780 INCOMPATIBILITY.
  3781 
  3782 * Locale "partial_order" now unified with class "order" (cf. theory
  3783 Orderings), added parameter "less".  INCOMPATIBILITY.
  3784 
  3785 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3786 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3787 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3788 
  3789 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3790 changed order of proof goals in instance proofs.
  3791 
  3792 * The transitivity reasoner for partial and linear orders is set up
  3793 for classes "order" and "linorder".  Instances of the reasoner are available
  3794 in all contexts importing or interpreting the corresponding locales.
  3795 Method "order" invokes the reasoner separately; the reasoner
  3796 is also integrated with the Simplifier as a solver.  Diagnostic
  3797 command 'print_orders' shows the available instances of the reasoner
  3798 in the current context.
  3799 
  3800 * Localized monotonicity predicate in theory "Orderings"; integrated
  3801 lemmas max_of_mono and min_of_mono with this predicate.
  3802 INCOMPATIBILITY.
  3803 
  3804 * Formulation of theorem "dense" changed slightly due to integration
  3805 with new class dense_linear_order.
  3806 
  3807 * Uniform lattice theory development in HOL.
  3808 
  3809     constants "meet" and "join" now named "inf" and "sup"
  3810     constant "Meet" now named "Inf"
  3811 
  3812     classes "meet_semilorder" and "join_semilorder" now named
  3813       "lower_semilattice" and "upper_semilattice"
  3814     class "lorder" now named "lattice"
  3815     class "comp_lat" now named "complete_lattice"
  3816 
  3817     Instantiation of lattice classes allows explicit definitions
  3818     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3819 
  3820   INCOMPATIBILITY.  Theorem renames:
  3821 
  3822     meet_left_le            ~> inf_le1
  3823     meet_right_le           ~> inf_le2
  3824     join_left_le            ~> sup_ge1
  3825     join_right_le           ~> sup_ge2
  3826     meet_join_le            ~> inf_sup_ord
  3827     le_meetI                ~> le_infI
  3828     join_leI                ~> le_supI
  3829     le_meet                 ~> le_inf_iff
  3830     le_join                 ~> ge_sup_conv
  3831     meet_idempotent         ~> inf_idem
  3832     join_idempotent         ~> sup_idem
  3833     meet_comm               ~> inf_commute
  3834     join_comm               ~> sup_commute
  3835     meet_leI1               ~> le_infI1
  3836     meet_leI2               ~> le_infI2
  3837     le_joinI1               ~> le_supI1
  3838     le_joinI2               ~> le_supI2
  3839     meet_assoc              ~> inf_assoc
  3840     join_assoc              ~> sup_assoc
  3841     meet_left_comm          ~> inf_left_commute
  3842     meet_left_idempotent    ~> inf_left_idem
  3843     join_left_comm          ~> sup_left_commute
  3844     join_left_idempotent    ~> sup_left_idem
  3845     meet_aci                ~> inf_aci
  3846     join_aci                ~> sup_aci
  3847     le_def_meet             ~> le_iff_inf
  3848     le_def_join             ~> le_iff_sup
  3849     join_absorp2            ~> sup_absorb2
  3850     join_absorp1            ~> sup_absorb1
  3851     meet_absorp1            ~> inf_absorb1
  3852     meet_absorp2            ~> inf_absorb2
  3853     meet_join_absorp        ~> inf_sup_absorb
  3854     join_meet_absorp        ~> sup_inf_absorb
  3855     distrib_join_le         ~> distrib_sup_le
  3856     distrib_meet_le         ~> distrib_inf_le
  3857 
  3858     add_meet_distrib_left   ~> add_inf_distrib_left
  3859     add_join_distrib_left   ~> add_sup_distrib_left
  3860     is_join_neg_meet        ~> is_join_neg_inf
  3861     is_meet_neg_join        ~> is_meet_neg_sup
  3862     add_meet_distrib_right  ~> add_inf_distrib_right
  3863     add_join_distrib_right  ~> add_sup_distrib_right
  3864     add_meet_join_distribs  ~> add_sup_inf_distribs
  3865     join_eq_neg_meet        ~> sup_eq_neg_inf
  3866     meet_eq_neg_join        ~> inf_eq_neg_sup
  3867     add_eq_meet_join        ~> add_eq_inf_sup
  3868     meet_0_imp_0            ~> inf_0_imp_0
  3869     join_0_imp_0            ~> sup_0_imp_0
  3870     meet_0_eq_0             ~> inf_0_eq_0
  3871     join_0_eq_0             ~> sup_0_eq_0
  3872     neg_meet_eq_join        ~> neg_inf_eq_sup
  3873     neg_join_eq_meet        ~> neg_sup_eq_inf
  3874     join_eq_if              ~> sup_eq_if
  3875 
  3876     mono_meet               ~> mono_inf
  3877     mono_join               ~> mono_sup
  3878     meet_bool_eq            ~> inf_bool_eq
  3879     join_bool_eq            ~> sup_bool_eq
  3880     meet_fun_eq             ~> inf_fun_eq
  3881     join_fun_eq             ~> sup_fun_eq
  3882     meet_set_eq             ~> inf_set_eq
  3883     join_set_eq             ~> sup_set_eq
  3884     meet1_iff               ~> inf1_iff
  3885     meet2_iff               ~> inf2_iff
  3886     meet1I                  ~> inf1I
  3887     meet2I                  ~> inf2I
  3888     meet1D1                 ~> inf1D1
  3889     meet2D1                 ~> inf2D1
  3890     meet1D2                 ~> inf1D2
  3891     meet2D2                 ~> inf2D2
  3892     meet1E                  ~> inf1E
  3893     meet2E                  ~> inf2E
  3894     join1_iff               ~> sup1_iff
  3895     join2_iff               ~> sup2_iff
  3896     join1I1                 ~> sup1I1
  3897     join2I1                 ~> sup2I1
  3898     join1I1                 ~> sup1I1
  3899     join2I2                 ~> sup1I2
  3900     join1CI                 ~> sup1CI
  3901     join2CI                 ~> sup2CI
  3902     join1E                  ~> sup1E
  3903     join2E                  ~> sup2E
  3904 
  3905     is_meet_Meet            ~> is_meet_Inf
  3906     Meet_bool_def           ~> Inf_bool_def
  3907     Meet_fun_def            ~> Inf_fun_def
  3908     Meet_greatest           ~> Inf_greatest
  3909     Meet_lower              ~> Inf_lower
  3910     Meet_set_def            ~> Inf_set_def
  3911 
  3912     Sup_def                 ~> Sup_Inf
  3913     Sup_bool_eq             ~> Sup_bool_def
  3914     Sup_fun_eq              ~> Sup_fun_def
  3915     Sup_set_eq              ~> Sup_set_def
  3916 
  3917     listsp_meetI            ~> listsp_infI
  3918     listsp_meet_eq          ~> listsp_inf_eq
  3919 
  3920     meet_min                ~> inf_min
  3921     join_max                ~> sup_max
  3922 
  3923 * Added syntactic class "size"; overloaded constant "size" now has
  3924 type "'a::size ==> bool"
  3925 
  3926 * Internal reorganisation of `size' of datatypes: size theorems
  3927 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3928 simplification rules by default!); theorems "prod.size" now named
  3929 "*.size".
  3930 
  3931 * Class "div" now inherits from class "times" rather than "type".
  3932 INCOMPATIBILITY.
  3933 
  3934 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3935 Linorder etc.  have disappeared; operations defined in terms of
  3936 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3937 
  3938 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3939 
  3940 * HOL-Word: New extensive library and type for generic, fixed size
  3941 machine words, with arithemtic, bit-wise, shifting and rotating
  3942 operations, reflection into int, nat, and bool lists, automation for
  3943 linear arithmetic (by automatic reflection into nat or int), including
  3944 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3945 arithmetic type classes, supporting automatic simplification of
  3946 numerals on all operations.
  3947 
  3948 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3949 
  3950 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3951 
  3952 * Code generator library theories:
  3953   - Code_Integer represents HOL integers by big integer literals in target
  3954     languages.
  3955   - Code_Char represents HOL characters by character literals in target
  3956     languages.
  3957   - Code_Char_chr like Code_Char, but also offers treatment of character
  3958     codes; includes Code_Integer.
  3959   - Executable_Set allows to generate code for finite sets using lists.
  3960   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3961     denominator).
  3962   - Executable_Real implements a subset of real numbers, namly those
  3963     representable by rational numbers.
  3964   - Efficient_Nat implements natural numbers by integers, which in general will
  3965     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3966     includes Code_Integer.
  3967   - Code_Index provides an additional datatype index which is mapped to
  3968     target-language built-in integers.
  3969   - Code_Message provides an additional datatype message_string which is isomorphic to
  3970     strings; messages are mapped to target-language strings.
  3971 
  3972 * New package for inductive predicates
  3973 
  3974   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3975 
  3976     inductive
  3977       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3978       for z_1 :: U_1 and ... and z_n :: U_m
  3979     where
  3980       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3981     | ...
  3982 
  3983   with full support for type-inference, rather than
  3984 
  3985     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3986 
  3987     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3988     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3989 
  3990     inductive "s z_1 ... z_m"
  3991     intros
  3992       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3993       ...
  3994 
  3995   For backward compatibility, there is a wrapper allowing inductive
  3996   sets to be defined with the new package via
  3997 
  3998     inductive_set
  3999       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4000       for z_1 :: U_1 and ... and z_n :: U_m
  4001     where
  4002       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4003     | ...
  4004 
  4005   or
  4006 
  4007     inductive_set
  4008       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4009       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4010       for z_1 :: U_1 and ... and z_n :: U_m
  4011     where
  4012       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4013     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4014     | ...
  4015 
  4016   if the additional syntax "p ..." is required.
  4017 
  4018   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4019   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4020 
  4021   INCOMPATIBILITIES:
  4022 
  4023   - Since declaration and definition of inductive sets or predicates
  4024     is no longer separated, abbreviations involving the newly
  4025     introduced sets or predicates must be specified together with the
  4026     introduction rules after the 'where' keyword (see above), rather
  4027     than before the actual inductive definition.
  4028 
  4029   - The variables in induction and elimination rules are now
  4030     quantified in the order of their occurrence in the introduction
  4031     rules, rather than in alphabetical order. Since this may break
  4032     some proofs, these proofs either have to be repaired, e.g. by
  4033     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4034     statements of the form
  4035 
  4036       case (rule_i a_i_1 ... a_i_{k_i})
  4037 
  4038     or the old order of quantification has to be restored by explicitly adding
  4039     meta-level quantifiers in the introduction rules, i.e.
  4040 
  4041       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4042 
  4043   - The format of the elimination rules is now
  4044 
  4045       p z_1 ... z_m x_1 ... x_n ==>
  4046         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4047         ==> ... ==> P
  4048 
  4049     for predicates and
  4050 
  4051       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4052         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4053         ==> ... ==> P
  4054 
  4055     for sets rather than
  4056 
  4057       x : s z_1 ... z_m ==>
  4058         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4059         ==> ... ==> P
  4060 
  4061     This may require terms in goals to be expanded to n-tuples
  4062     (e.g. using case_tac or simplification with the split_paired_all
  4063     rule) before the above elimination rule is applicable.
  4064 
  4065   - The elimination or case analysis rules for (mutually) inductive
  4066     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4067     list of rules "p_1_..._p_k.elims" is no longer available.
  4068 
  4069 * New package "function"/"fun" for general recursive functions,
  4070 supporting mutual and nested recursion, definitions in local contexts,
  4071 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4072 for small examples, and the separate tutorial on the function
  4073 package. The old recdef "package" is still available as before, but
  4074 users are encouraged to use the new package.
  4075 
  4076 * Method "lexicographic_order" automatically synthesizes termination
  4077 relations as lexicographic combinations of size measures. 
  4078 
  4079 * Case-expressions allow arbitrary constructor-patterns (including
  4080 "_") and take their order into account, like in functional
  4081 programming.  Internally, this is translated into nested
  4082 case-expressions; missing cases are added and mapped to the predefined
  4083 constant "undefined". In complicated cases printing may no longer show
  4084 the original input but the internal form. Lambda-abstractions allow
  4085 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4086 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4087 variable.
  4088 
  4089 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4090 is an abbreviation for "of_nat :: nat => int". The simplification
  4091 rules for "of_nat" have been changed to work like "int" did
  4092 previously.  Potential INCOMPATIBILITY:
  4093   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4094   - of_nat_diff and of_nat_mult are no longer default simp rules
  4095 
  4096 * Method "algebra" solves polynomial equations over (semi)rings using
  4097 Groebner bases. The (semi)ring structure is defined by locales and the
  4098 tool setup depends on that generic context. Installing the method for
  4099 a specific type involves instantiating the locale and possibly adding
  4100 declarations for computation on the coefficients.  The method is
  4101 already instantiated for natural numbers and for the axiomatic class
  4102 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4103 CALCULEMUS 2007 for the general principles underlying this
  4104 architecture of context-aware proof-tools.
  4105 
  4106 * Method "ferrack" implements quantifier elimination over
  4107 special-purpose dense linear orders using locales (analogous to
  4108 "algebra"). The method is already installed for class
  4109 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4110 rat, etc.
  4111 
  4112 * Former constant "List.op @" now named "List.append".  Use ML
  4113 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4114 circumvent possible incompatibilities when working on ML level.
  4115 
  4116 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4117 
  4118 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4119 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4120 
  4121 * New syntax for Haskell-like list comprehension (input only), eg.
  4122 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4123 
  4124 * The special syntax for function "filter" has changed from [x :
  4125 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4126 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4127 
  4128 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4129 defined on nat only, as an abbreviation for [a..<Suc b]
  4130 INCOMPATIBILITY.
  4131 
  4132 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4133 
  4134 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4135 
  4136 * New lemma collection field_simps (an extension of ring_simps) for
  4137 manipulating (in)equations involving division. Multiplies with all
  4138 denominators that can be proved to be non-zero (in equations) or
  4139 positive/negative (in inequations).
  4140 
  4141 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4142 have been improved and renamed to ring_simps, group_simps and
  4143 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4144 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4145 
  4146 * Theory Library/Commutative_Ring: switched from recdef to function
  4147 package; constants add, mul, pow now curried.  Infix syntax for
  4148 algebraic operations.
  4149 
  4150 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4151 INCOMPATIBILITY.
  4152 
  4153 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4154 INCOMPATIBILITY.
  4155 
  4156 * HOL/records: generalised field-update to take a function on the
  4157 field rather than the new value: r(|A := x|) is translated to A_update
  4158 (K x) r The K-combinator that is internally used is called K_record.
  4159 INCOMPATIBILITY: Usage of the plain update functions has to be
  4160 adapted.
  4161  
  4162 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4163 * x = 0, which are required for a semiring.  Richer structures do not
  4164 inherit from semiring_0 anymore, because this property is a theorem
  4165 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4166 there is more to prove, but this is mostly trivial.
  4167 
  4168 * Class "recpower" is generalized to arbitrary monoids, not just
  4169 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4170 commutativity or semiring properties additionally.
  4171 
  4172 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4173 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4174 better use 'abbreviation'.
  4175 
  4176 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4177 
  4178 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4179 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4180 significant changes for setting up numeral syntax for types:
  4181   - New constants Numeral.pred and Numeral.succ instead
  4182       of former Numeral.bin_pred and Numeral.bin_succ.
  4183   - Use integer operations instead of bin_add, bin_mult and so on.
  4184   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4185   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4186 
  4187 See src/HOL/Integ/IntArith.thy for an example setup.
  4188 
  4189 * Command 'normal_form' computes the normal form of a term that may
  4190 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4191 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4192 heavy-duty computations because the functions are compiled to ML
  4193 first.  Correspondingly, a method "normalization" is provided.  See
  4194 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4195 
  4196 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4197 25 like -->); output depends on the "iff" print_mode, the default is
  4198 "A = B" (with priority 50).
  4199 
  4200 * Relations less (<) and less_eq (<=) are also available on type bool.
  4201 Modified syntax to disallow nesting without explicit parentheses,
  4202 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4203 INCOMPATIBILITY.
  4204 
  4205 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4206 
  4207 * Relation composition operator "op O" now has precedence 75 and binds
  4208 stronger than union and intersection. INCOMPATIBILITY.
  4209 
  4210 * The old set interval syntax "{m..n(}" (and relatives) has been
  4211 removed.  Use "{m..<n}" (and relatives) instead.
  4212 
  4213 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4214 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4215 ``declare [[simproc del: neq]]''.
  4216 
  4217 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4218 True/False.
  4219 
  4220 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4221 
  4222 * Theorem setsum_mult renamed to setsum_right_distrib.
  4223 
  4224 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4225 ``rule'' method.
  4226 
  4227 * Reimplemented methods "sat" and "satx", with several improvements:
  4228 goals no longer need to be stated as "<prems> ==> False", equivalences
  4229 (i.e. "=" on type bool) are handled, variable names of the form
  4230 "lit_<n>" are no longer reserved, significant speedup.
  4231 
  4232 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4233 zChaff is still supported as well.
  4234 
  4235 * 'inductive' and 'datatype': provide projections of mutual rules,
  4236 bundled as foo_bar.inducts;
  4237 
  4238 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4239 Library.
  4240 
  4241 * Library: moved theory Accessible_Part to main HOL.
  4242 
  4243 * Library: added theory Coinductive_List of potentially infinite lists
  4244 as greatest fixed-point.
  4245 
  4246 * Library: added theory AssocList which implements (finite) maps as
  4247 association lists.
  4248 
  4249 * Method "evaluation" solves goals (i.e. a boolean expression)
  4250 efficiently by compiling it to ML.  The goal is "proved" (via an
  4251 oracle) if it evaluates to True.
  4252 
  4253 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4254 also when invoked by the simplifier.  This results in the Simplifier
  4255 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4256 Configuration option fast_arith_split_limit=0 recovers the old
  4257 behavior.
  4258 
  4259 * Support for hex (0x20) and binary (0b1001) numerals.
  4260 
  4261 * New method: reify eqs (t), where eqs are equations for an
  4262 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4263 parameter, computes a term s::'b and a list xs::'a list and proves the
  4264 theorem I xs s = t. This is also known as reification or quoting. The
  4265 resulting theorem is applied to the subgoal to substitute t with I xs
  4266 s.  If t is omitted, the subgoal itself is reified.
  4267 
  4268 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4269 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4270 where f is supposed to be a computable function (in the sense of code
  4271 generattion). The method uses reify to compute s and xs as above then
  4272 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4273 r and finally gets the theorem t = r, which is again applied to the
  4274 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4275 
  4276 * Reflection: Automatic reification now handels binding, an example is
  4277 available in src/HOL/ex/ReflectionEx.thy
  4278 
  4279 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4280 command 'statespace' that is similar to 'record', but introduces an
  4281 abstract specification based on the locale infrastructure instead of
  4282 HOL types.  This leads to extra flexibility in composing state spaces,
  4283 in particular multiple inheritance and renaming of components.
  4284 
  4285 
  4286 *** HOL-Complex ***
  4287 
  4288 * Hyperreal: Functions root and sqrt are now defined on negative real
  4289 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4290 Nonnegativity side conditions have been removed from many lemmas, so
  4291 that more subgoals may now be solved by simplification; potential
  4292 INCOMPATIBILITY.
  4293 
  4294 * Real: new type classes formalize real normed vector spaces and
  4295 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4296 and norm :: 'a => real.
  4297 
  4298 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4299 reals into other types. The overloaded constant Reals :: 'a set is now
  4300 defined as range of_real; potential INCOMPATIBILITY.
  4301 
  4302 * Real: proper support for ML code generation, including 'quickcheck'.
  4303 Reals are implemented as arbitrary precision rationals.
  4304 
  4305 * Hyperreal: Several constants that previously worked only for the
  4306 reals have been generalized, so they now work over arbitrary vector
  4307 spaces. Type annotations may need to be added in some cases; potential
  4308 INCOMPATIBILITY.
  4309 
  4310   Infinitesimal  :: ('a::real_normed_vector) star set
  4311   HFinite        :: ('a::real_normed_vector) star set
  4312   HInfinite      :: ('a::real_normed_vector) star set
  4313   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4314   monad          :: ('a::real_normed_vector) star => 'a star set
  4315   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4316   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4317   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4318   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4319   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4320   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4321   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4322   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4323   sgn            :: 'a::real_normed_vector => 'a
  4324   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4325 
  4326 * Complex: Some complex-specific constants are now abbreviations for
  4327 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4328 hnorm.  Other constants have been entirely removed in favor of the
  4329 polymorphic versions (INCOMPATIBILITY):
  4330 
  4331   approx        <-- capprox
  4332   HFinite       <-- CFinite
  4333   HInfinite     <-- CInfinite
  4334   Infinitesimal <-- CInfinitesimal
  4335   monad         <-- cmonad
  4336   galaxy        <-- cgalaxy
  4337   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4338   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4339   (ns)deriv     <-- (ns)cderiv
  4340 
  4341 
  4342 *** HOL-Algebra ***
  4343 
  4344 * Formalisation of ideals and the quotient construction over rings.
  4345 
  4346 * Order and lattice theory no longer based on records.
  4347 INCOMPATIBILITY.
  4348 
  4349 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4350 greatest_closed.  INCOMPATIBILITY.
  4351 
  4352 * Method algebra is now set up via an attribute.  For examples see
  4353 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4354 of algebraic structures.
  4355 
  4356 * Renamed theory CRing to Ring.
  4357 
  4358 
  4359 *** HOL-Nominal ***
  4360 
  4361 * Substantial, yet incomplete support for nominal datatypes (binding
  4362 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4363 src/HOL/Nominal/Examples.  Prospective users should consult
  4364 http://isabelle.in.tum.de/nominal/
  4365 
  4366 
  4367 *** ML ***
  4368 
  4369 * ML basics: just one true type int, which coincides with IntInf.int
  4370 (even on SML/NJ).
  4371 
  4372 * ML within Isar: antiquotations allow to embed statically-checked
  4373 formal entities in the source, referring to the context available at
  4374 compile-time.  For example:
  4375 
  4376 ML {* @{sort "{zero,one}"} *}
  4377 ML {* @{typ "'a => 'b"} *}
  4378 ML {* @{term "%x. x"} *}
  4379 ML {* @{prop "x == y"} *}
  4380 ML {* @{ctyp "'a => 'b"} *}
  4381 ML {* @{cterm "%x. x"} *}
  4382 ML {* @{cprop "x == y"} *}
  4383 ML {* @{thm asm_rl} *}
  4384 ML {* @{thms asm_rl} *}
  4385 ML {* @{type_name c} *}
  4386 ML {* @{type_syntax c} *}
  4387 ML {* @{const_name c} *}
  4388 ML {* @{const_syntax c} *}
  4389 ML {* @{context} *}
  4390 ML {* @{theory} *}
  4391 ML {* @{theory Pure} *}
  4392 ML {* @{theory_ref} *}
  4393 ML {* @{theory_ref Pure} *}
  4394 ML {* @{simpset} *}
  4395 ML {* @{claset} *}
  4396 ML {* @{clasimpset} *}
  4397 
  4398 The same works for sources being ``used'' within an Isar context.
  4399 
  4400 * ML in Isar: improved error reporting; extra verbosity with
  4401 ML_Context.trace enabled.
  4402 
  4403 * Pure/General/table.ML: the join operations now works via exceptions
  4404 DUP/SAME instead of type option. This is simpler in simple cases, and
  4405 admits slightly more efficient complex applications.
  4406 
  4407 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4408 use Context.generic instead of just theory.
  4409 
  4410 * Pure: datatype Context.generic joins theory/Proof.context and
  4411 provides some facilities for code that works in either kind of
  4412 context, notably GenericDataFun for uniform theory and proof data.
  4413 
  4414 * Pure: simplified internal attribute type, which is now always
  4415 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4416 local (Proof.context) attributes have been discontinued, while
  4417 minimizing code duplication. Thm.rule_attribute and
  4418 Thm.declaration_attribute build canonical attributes; see also structure
  4419 Context for further operations on Context.generic, notably
  4420 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4421 declarations and definitions.
  4422 
  4423 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4424 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4425 init only required for impure data. INCOMPATIBILITY: empty really need
  4426 to be empty (no dependencies on theory content!)
  4427 
  4428 * Pure/kernel: consts certification ignores sort constraints given in
  4429 signature declarations. (This information is not relevant to the
  4430 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4431 potential INCOMPATIBILITY.
  4432 
  4433 * Pure: axiomatic type classes are now purely definitional, with
  4434 explicit proofs of class axioms and super class relations performed
  4435 internally. See Pure/axclass.ML for the main internal interfaces --
  4436 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4437 AxClass.axiomatize_class/classrel/arity supersede
  4438 Sign.add_classes/classrel/arities.
  4439 
  4440 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4441 global/local versions on theory vs. Proof.context have been
  4442 discontinued; Attrib.syntax and Method.syntax have been adapted
  4443 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4444 attributes, methods, etc.
  4445 
  4446 * Pure: several functions of signature "... -> theory -> theory * ..."
  4447 have been reoriented to "... -> theory -> ... * theory" in order to
  4448 allow natural usage in combination with the ||>, ||>>, |-> and
  4449 fold_map combinators.
  4450 
  4451 * Pure: official theorem names (closed derivations) and additional
  4452 comments (tags) are now strictly separate.  Name hints -- which are
  4453 maintained as tags -- may be attached any time without affecting the
  4454 derivation.
  4455 
  4456 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4457 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4458 achieve the old behaviour.
  4459 
  4460 * Pure: the "Goal" constant is now called "prop", supporting a
  4461 slightly more general idea of ``protecting'' meta-level rule
  4462 statements.
  4463 
  4464 * Pure: Logic.(un)varify only works in a global context, which is now
  4465 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4466 Logic.legacy_(un)varify as temporary workaround.
  4467 
  4468 * Pure: structure Name provides scalable operations for generating
  4469 internal variable names, notably Name.variants etc.  This replaces
  4470 some popular functions from term.ML:
  4471 
  4472   Term.variant		->  Name.variant
  4473   Term.variantlist	->  Name.variant_list
  4474   Term.invent_names	->  Name.invent_list
  4475 
  4476 Note that low-level renaming rarely occurs in new code -- operations
  4477 from structure Variable are used instead (see below).
  4478 
  4479 * Pure: structure Variable provides fundamental operations for proper
  4480 treatment of fixed/schematic variables in a context.  For example,
  4481 Variable.import introduces fixes for schematics of given facts and
  4482 Variable.export reverses the effect (up to renaming) -- this replaces
  4483 various freeze_thaw operations.
  4484 
  4485 * Pure: structure Goal provides simple interfaces for
  4486 init/conclude/finish and tactical prove operations (replacing former
  4487 Tactic.prove).  Goal.prove is the canonical way to prove results
  4488 within a given context; Goal.prove_global is a degraded version for
  4489 theory level goals, including a global Drule.standard.  Note that
  4490 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4491 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4492 in a locale context).
  4493 
  4494 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4495 and type checking (Syntax.check_term etc.), with common combinations
  4496 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4497 which are considered legacy and await removal.
  4498 
  4499 * Pure/Syntax: generic interfaces for type unchecking
  4500 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4501 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4502 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4503 available for convenience, but refer to the very same operations using
  4504 a mere theory instead of a full context.
  4505 
  4506 * Isar: simplified treatment of user-level errors, using exception
  4507 ERROR of string uniformly.  Function error now merely raises ERROR,
  4508 without any side effect on output channels.  The Isar toplevel takes
  4509 care of proper display of ERROR exceptions.  ML code may use plain
  4510 handle/can/try; cat_error may be used to concatenate errors like this:
  4511 
  4512   ... handle ERROR msg => cat_error msg "..."
  4513 
  4514 Toplevel ML code (run directly or through the Isar toplevel) may be
  4515 embedded into the Isar toplevel with exception display/debug like
  4516 this:
  4517 
  4518   Isar.toplevel (fn () => ...)
  4519 
  4520 INCOMPATIBILITY, removed special transform_error facilities, removed
  4521 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4522 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4523 -- use plain ERROR instead.
  4524 
  4525 * Isar: theory setup now has type (theory -> theory), instead of a
  4526 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4527 
  4528 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4529 ProofContext.debug/verbose flags.
  4530 
  4531 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4532 theory before entering a proof state.  Transactions now always see a
  4533 quasi-functional intermediate checkpoint, both in interactive and
  4534 batch mode.
  4535 
  4536 * Isar: simplified interfaces for outer syntax.  Renamed
  4537 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4538 OuterSyntax.add_parsers -- this functionality is now included in
  4539 OuterSyntax.command etc.  INCOMPATIBILITY.
  4540 
  4541 * Simplifier: the simpset of a running simplification process now
  4542 contains a proof context (cf. Simplifier.the_context), which is the
  4543 very context that the initial simpset has been retrieved from (by
  4544 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4545 (solver, looper etc.) may depend on arbitrary proof data.
  4546 
  4547 * Simplifier.inherit_context inherits the proof context (plus the
  4548 local bounds) of the current simplification process; any simproc
  4549 etc. that calls the Simplifier recursively should do this!  Removed
  4550 former Simplifier.inherit_bounds, which is already included here --
  4551 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4552 specify an explicit context using Simplifier.context/theory_context.
  4553 
  4554 * Simplifier/Classical Reasoner: more abstract interfaces
  4555 change_simpset/claset for modifying the simpset/claset reference of a
  4556 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4557 INCOMPATIBILITY.
  4558 
  4559 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4560 "Trueprop" etc.
  4561 
  4562 
  4563 *** System ***
  4564 
  4565 * settings: the default heap location within ISABELLE_HOME_USER now
  4566 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4567 Isabelle installations.
  4568 
  4569 * isabelle-process: option -S (secure mode) disables some critical
  4570 operations, notably runtime compilation and evaluation of ML source
  4571 code.
  4572 
  4573 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4574 
  4575 * Support for parallel execution, using native multicore support of
  4576 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4577 independent theories, according to the given theory header
  4578 specifications. The maximum number of worker threads is specified via
  4579 usedir option -M or the "max-threads" setting in Proof General. A
  4580 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4581 to 6 on a 8-core machine.  User-code needs to observe certain
  4582 guidelines for thread-safe programming, see appendix A in the Isar
  4583 Implementation manual.
  4584 
  4585 
  4586 
  4587 New in Isabelle2005 (October 2005)
  4588 ----------------------------------
  4589 
  4590 *** General ***
  4591 
  4592 * Theory headers: the new header syntax for Isar theories is
  4593 
  4594   theory <name>
  4595   imports <theory1> ... <theoryN>
  4596   uses <file1> ... <fileM>
  4597   begin
  4598 
  4599 where the 'uses' part is optional.  The previous syntax
  4600 
  4601   theory <name> = <theory1> + ... + <theoryN>:
  4602 
  4603 will disappear in the next release.  Use isatool fixheaders to convert
  4604 existing theory files.  Note that there is no change in ancient
  4605 non-Isar theories now, but these will disappear soon.
  4606 
  4607 * Theory loader: parent theories can now also be referred to via
  4608 relative and absolute paths.
  4609 
  4610 * Command 'find_theorems' searches for a list of criteria instead of a
  4611 list of constants. Known criteria are: intro, elim, dest, name:string,
  4612 simp:term, and any term. Criteria can be preceded by '-' to select
  4613 theorems that do not match. Intro, elim, dest select theorems that
  4614 match the current goal, name:s selects theorems whose fully qualified
  4615 name contain s, and simp:term selects all simplification rules whose
  4616 lhs match term.  Any other term is interpreted as pattern and selects
  4617 all theorems matching the pattern. Available in ProofGeneral under
  4618 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4619 
  4620   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4621 
  4622 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4623 matching the current goal as introduction rule and not having "HOL."
  4624 in their name (i.e. not being defined in theory HOL).
  4625 
  4626 * Command 'thms_containing' has been discontinued in favour of
  4627 'find_theorems'; INCOMPATIBILITY.
  4628 
  4629 * Communication with Proof General is now 8bit clean, which means that
  4630 Unicode text in UTF-8 encoding may be used within theory texts (both
  4631 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4632 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4633 
  4634   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4635   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4636 
  4637 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4638 Classical Reasoner.  Typical big applications run around 2 times
  4639 faster.
  4640 
  4641 
  4642 *** Document preparation ***
  4643 
  4644 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4645 of raw sources.  Only those symbols that do not require additional
  4646 LaTeX packages (depending on comments in isabellesym.sty) are
  4647 displayed properly, everything else is left verbatim.  isatool display
  4648 and isatool print are used as front ends (these are subject to the
  4649 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4650 
  4651 * Command tags control specific markup of certain regions of text,
  4652 notably folding and hiding.  Predefined tags include "theory" (for
  4653 theory begin and end), "proof" for proof commands, and "ML" for
  4654 commands involving ML code; the additional tags "visible" and
  4655 "invisible" are unused by default.  Users may give explicit tag
  4656 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4657 interpretation of tags is determined by the LaTeX job during document
  4658 preparation: see option -V of isatool usedir, or options -n and -t of
  4659 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4660 \isadroptag.
  4661 
  4662 Several document versions may be produced at the same time via isatool
  4663 usedir (the generated index.html will link all of them).  Typical
  4664 specifications include ''-V document=theory,proof,ML'' to present
  4665 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4666 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4667 these parts without any formal replacement text.  The Isabelle site
  4668 default settings produce ''document'' and ''outline'' versions as
  4669 specified above.
  4670 
  4671 * Several new antiquotations:
  4672 
  4673   @{term_type term} prints a term with its type annotated;
  4674 
  4675   @{typeof term} prints the type of a term;
  4676 
  4677   @{const const} is the same as @{term const}, but checks that the
  4678   argument is a known logical constant;
  4679 
  4680   @{term_style style term} and @{thm_style style thm} print a term or
  4681   theorem applying a "style" to it
  4682 
  4683   @{ML text}
  4684 
  4685 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4686 definitions, equations, inequations etc., 'concl' printing only the
  4687 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4688 to print the specified premise.  TermStyle.add_style provides an ML
  4689 interface for introducing further styles.  See also the "LaTeX Sugar"
  4690 document practical applications.  The ML antiquotation prints
  4691 type-checked ML expressions verbatim.
  4692 
  4693 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4694 and 'text' support optional locale specification '(in loc)', which
  4695 specifies the default context for interpreting antiquotations.  For
  4696 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4697 
  4698 * Option 'locale=NAME' of antiquotations specifies an alternative
  4699 context interpreting the subsequent argument.  For example: @{thm
  4700 [locale=lattice] inf_assoc}.
  4701 
  4702 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4703 a proof context.
  4704 
  4705 * Proper output of antiquotations for theory commands involving a
  4706 proof context (such as 'locale' or 'theorem (in loc) ...').
  4707 
  4708 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4709 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4710 
  4711 * isatool usedir: new option -C (default true) controls whether option
  4712 -D should include a copy of the original document directory; -C false
  4713 prevents unwanted effects such as copying of administrative CVS data.
  4714 
  4715 
  4716 *** Pure ***
  4717 
  4718 * Considerably improved version of 'constdefs' command.  Now performs
  4719 automatic type-inference of declared constants; additional support for
  4720 local structure declarations (cf. locales and HOL records), see also
  4721 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4722 sequential dependencies of definitions within a single 'constdefs'
  4723 section; moreover, the declared name needs to be an identifier.  If
  4724 all fails, consider to fall back on 'consts' and 'defs' separately.
  4725 
  4726 * Improved indexed syntax and implicit structures.  First of all,
  4727 indexed syntax provides a notational device for subscripted
  4728 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4729 expressions.  Secondly, in a local context with structure
  4730 declarations, number indexes \<^sub>n or the empty index (default
  4731 number 1) refer to a certain fixed variable implicitly; option
  4732 show_structs controls printing of implicit structures.  Typical
  4733 applications of these concepts involve record types and locales.
  4734 
  4735 * New command 'no_syntax' removes grammar declarations (and
  4736 translations) resulting from the given syntax specification, which is
  4737 interpreted in the same manner as for the 'syntax' command.
  4738 
  4739 * 'Advanced' translation functions (parse_translation etc.) may depend
  4740 on the signature of the theory context being presently used for
  4741 parsing/printing, see also isar-ref manual.
  4742 
  4743 * Improved 'oracle' command provides a type-safe interface to turn an
  4744 ML expression of type theory -> T -> term into a primitive rule of
  4745 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4746 is already included here); see also FOL/ex/IffExample.thy;
  4747 INCOMPATIBILITY.
  4748 
  4749 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4750 before); "cI" is no longer bound, use "c.intro" instead.
  4751 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4752 axclasses vs. locales.
  4753 
  4754 * Improved internal renaming of symbolic identifiers -- attach primes
  4755 instead of base 26 numbers.
  4756 
  4757 * New flag show_question_marks controls printing of leading question
  4758 marks in schematic variable names.
  4759 
  4760 * In schematic variable names, *any* symbol following \<^isub> or
  4761 \<^isup> is now treated as part of the base name.  For example, the
  4762 following works without printing of awkward ".0" indexes:
  4763 
  4764   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4765     by simp
  4766 
  4767 * Inner syntax includes (*(*nested*) comments*).
  4768 
  4769 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4770 annotations as "(00...)".
  4771 
  4772 * Clear separation of logical types and nonterminals, where the latter
  4773 may only occur in 'syntax' specifications or type abbreviations.
  4774 Before that distinction was only partially implemented via type class
  4775 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4776 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4777 exotic syntax specifications may require further adaption
  4778 (e.g. Cube/Cube.thy).
  4779 
  4780 * Removed obsolete type class "logic", use the top sort {} instead.
  4781 Note that non-logical types should be declared as 'nonterminals'
  4782 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4783 specifications.
  4784 
  4785 * Attributes 'induct' and 'cases': type or set names may now be
  4786 locally fixed variables as well.
  4787 
  4788 * Simplifier: can now control the depth to which conditional rewriting
  4789 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4790 Limit.
  4791 
  4792 * Simplifier: simplification procedures may now take the current
  4793 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4794 interface), which is very useful for calling the Simplifier
  4795 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4796 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4797 low-level mk_simproc no longer applies Logic.varify internally, to
  4798 allow for use in a context of fixed variables.
  4799 
  4800 * thin_tac now works even if the assumption being deleted contains !!
  4801 or ==>.  More generally, erule now works even if the major premise of
  4802 the elimination rule contains !! or ==>.
  4803 
  4804 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4805 
  4806 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4807 from Pure, which contains all common declarations already.  Both
  4808 theories are defined via plain Isabelle/Isar .thy files.
  4809 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4810 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4811 use isatool fixcpure to adapt your theory and ML sources.
  4812 
  4813 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4814 selections of theorems in named facts via index ranges.
  4815 
  4816 * 'print_theorems': in theory mode, really print the difference
  4817 wrt. the last state (works for interactive theory development only),
  4818 in proof mode print all local facts (cf. 'print_facts');
  4819 
  4820 * 'hide': option '(open)' hides only base names.
  4821 
  4822 * More efficient treatment of intermediate checkpoints in interactive
  4823 theory development.
  4824 
  4825 * Code generator is now invoked via code_module (incremental code
  4826 generation) and code_library (modular code generation, ML structures
  4827 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4828 must be quoted when used as identifiers.
  4829 
  4830 * New 'value' command for reading, evaluating and printing terms using
  4831 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4832 quoted when used as identifier.
  4833 
  4834 
  4835 *** Locales ***
  4836 
  4837 * New commands for the interpretation of locale expressions in
  4838 theories (1), locales (2) and proof contexts (3).  These generate
  4839 proof obligations from the expression specification.  After the
  4840 obligations have been discharged, theorems of the expression are added
  4841 to the theory, target locale or proof context.  The synopsis of the
  4842 commands is a follows:
  4843 
  4844   (1) interpretation expr inst
  4845   (2) interpretation target < expr
  4846   (3) interpret expr inst
  4847 
  4848 Interpretation in theories and proof contexts require a parameter
  4849 instantiation of terms from the current context.  This is applied to
  4850 specifications and theorems of the interpreted expression.
  4851 Interpretation in locales only permits parameter renaming through the
  4852 locale expression.  Interpretation is smart in that interpretations
  4853 that are active already do not occur in proof obligations, neither are
  4854 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4855 inspect active interpretations of a particular locale.  For details,
  4856 see the Isar Reference manual.  Examples can be found in
  4857 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4858 
  4859 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4860 'interpret' instead.
  4861 
  4862 * New context element 'constrains' for adding type constraints to
  4863 parameters.
  4864 
  4865 * Context expressions: renaming of parameters with syntax
  4866 redeclaration.
  4867 
  4868 * Locale declaration: 'includes' disallowed.
  4869 
  4870 * Proper static binding of attribute syntax -- i.e. types / terms /
  4871 facts mentioned as arguments are always those of the locale definition
  4872 context, independently of the context of later invocations.  Moreover,
  4873 locale operations (renaming and type / term instantiation) are applied
  4874 to attribute arguments as expected.
  4875 
  4876 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4877 actual attributes; rare situations may require Attrib.attribute to
  4878 embed those attributes into Attrib.src that lack concrete syntax.
  4879 Attribute implementations need to cooperate properly with the static
  4880 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4881 Attrib.XXX_thm etc. already do the right thing without further
  4882 intervention.  Only unusual applications -- such as "where" or "of"
  4883 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4884 on the context and the facts involved -- may have to assign parsed
  4885 values to argument tokens explicitly.
  4886 
  4887 * Changed parameter management in theorem generation for long goal
  4888 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4889 theorem statement in rare situations.
  4890 
  4891 * Locale inspection command 'print_locale' omits notes elements.  Use
  4892 'print_locale!' to have them included in the output.
  4893 
  4894 
  4895 *** Provers ***
  4896 
  4897 * Provers/hypsubst.ML: improved version of the subst method, for
  4898 single-step rewriting: it now works in bound variable contexts. New is
  4899 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4900 rewrite a different subterm than the original subst method, which is
  4901 still available as 'simplesubst'.
  4902 
  4903 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4904 and quasi orders.
  4905 
  4906 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4907 reflexive-transitive closure of relations.
  4908 
  4909 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4910 limit (previously hard-coded with a value of 20) user-definable.
  4911 
  4912 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4913 is peformed already.  Object-logics merely need to finish their
  4914 initial simpset configuration as before.  INCOMPATIBILITY.
  4915 
  4916 
  4917 *** HOL ***
  4918 
  4919 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4920 
  4921   syntax (epsilon)
  4922     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4923 
  4924 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4925 and x-symbol; use option '-m epsilon' to get it actually printed.
  4926 Moreover, the mathematically important symbolic identifier \<epsilon>
  4927 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4928 
  4929 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4930 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4931 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4932 support corresponding Isar calculations.
  4933 
  4934 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4935 instead of ":".
  4936 
  4937 * theory SetInterval: changed the syntax for open intervals:
  4938 
  4939   Old       New
  4940   {..n(}    {..<n}
  4941   {)n..}    {n<..}
  4942   {m..n(}   {m..<n}
  4943   {)m..n}   {m<..n}
  4944   {)m..n(}  {m<..<n}
  4945 
  4946 The old syntax is still supported but will disappear in the next
  4947 release.  For conversion use the following Emacs search and replace
  4948 patterns (these are not perfect but work quite well):
  4949 
  4950   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4951   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4952 
  4953 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4954 equalities in commutative rings; method 'algebra' provides a generic
  4955 interface.
  4956 
  4957 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4958 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4959 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4960 be a tuple pattern.
  4961 
  4962 Some new syntax forms are available:
  4963 
  4964   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4965   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4966   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4967   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4968 
  4969 The latter form "\<Sum>x < k. e" used to be based on a separate
  4970 function "Summation", which has been discontinued.
  4971 
  4972 * theory Finite_Set: in structured induction proofs, the insert case
  4973 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4974 (insert F x)'.
  4975 
  4976 * The 'refute' command has been extended to support a much larger
  4977 fragment of HOL, including axiomatic type classes, constdefs and
  4978 typedefs, inductive datatypes and recursion.
  4979 
  4980 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4981 Requires zChaff with proof generation to be installed.  See
  4982 HOL/ex/SAT_Examples.thy for examples.
  4983 
  4984 * Datatype induction via method 'induct' now preserves the name of the
  4985 induction variable. For example, when proving P(xs::'a list) by
  4986 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4987 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4988 in unstructured proof scripts.
  4989 
  4990 * Reworked implementation of records.  Improved scalability for
  4991 records with many fields, avoiding performance problems for type
  4992 inference. Records are no longer composed of nested field types, but
  4993 of nested extension types. Therefore the record type only grows linear
  4994 in the number of extensions and not in the number of fields.  The
  4995 top-level (users) view on records is preserved.  Potential
  4996 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4997 old record representation. The type generated for a record is called
  4998 <record_name>_ext_type.
  4999 
  5000 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5001 proofs triggered by a record definition or a simproc (if
  5002 quick_and_dirty is enabled).  Definitions of large records can take
  5003 quite long.
  5004 
  5005 New simproc record_upd_simproc for simplification of multiple record
  5006 updates enabled by default.  Moreover, trivial updates are also
  5007 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5008 occasionally, since simplification is more powerful by default.
  5009 
  5010 * typedef: proper support for polymorphic sets, which contain extra
  5011 type-variables in the term.
  5012 
  5013 * Simplifier: automatically reasons about transitivity chains
  5014 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5015 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5016 old proofs break occasionally as simplification may now solve more
  5017 goals than previously.
  5018 
  5019 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5020 present.  Works for all partial orders (class "order"), in particular
  5021 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5022 just like y <= x.
  5023 
  5024 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5025 bound variable or a constant then the let is unfolded.  Otherwise
  5026 first a is simplified to b, and then f b is simplified to g. If
  5027 possible we abstract b from g arriving at "let x = b in h x",
  5028 otherwise we unfold the let and arrive at g.  The simproc can be
  5029 enabled/disabled by the reference use_let_simproc.  Potential
  5030 INCOMPATIBILITY since simplification is more powerful by default.
  5031 
  5032 * Classical reasoning: the meson method now accepts theorems as arguments.
  5033 
  5034 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5035 jobs to provide advice on the provability of subgoals.
  5036 
  5037 * Theory OrderedGroup and Ring_and_Field: various additions and
  5038 improvements to faciliate calculations involving equalities and
  5039 inequalities.
  5040 
  5041 The following theorems have been eliminated or modified
  5042 (INCOMPATIBILITY):
  5043 
  5044   abs_eq             now named abs_of_nonneg
  5045   abs_of_ge_0        now named abs_of_nonneg
  5046   abs_minus_eq       now named abs_of_nonpos
  5047   imp_abs_id         now named abs_of_nonneg
  5048   imp_abs_neg_id     now named abs_of_nonpos
  5049   mult_pos           now named mult_pos_pos
  5050   mult_pos_le        now named mult_nonneg_nonneg
  5051   mult_pos_neg_le    now named mult_nonneg_nonpos
  5052   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5053   mult_neg           now named mult_neg_neg
  5054   mult_neg_le        now named mult_nonpos_nonpos
  5055 
  5056 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5057      
  5058      zero_le_square
  5059      not_square_less_zero 
  5060 
  5061   The following lemmas have been deleted from Real/RealPow:
  5062   
  5063      realpow_zero_zero
  5064      realpow_two
  5065      realpow_less
  5066      zero_le_power
  5067      realpow_two_le
  5068      abs_realpow_two
  5069      realpow_two_abs     
  5070 
  5071 * Theory Parity: added rules for simplifying exponents.
  5072 
  5073 * Theory List:
  5074 
  5075 The following theorems have been eliminated or modified
  5076 (INCOMPATIBILITY):
  5077 
  5078   list_all_Nil       now named list_all.simps(1)
  5079   list_all_Cons      now named list_all.simps(2)
  5080   list_all_conv      now named list_all_iff
  5081   set_mem_eq         now named mem_iff
  5082 
  5083 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5084 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5085 
  5086 
  5087 *** HOL-Complex ***
  5088 
  5089 * Theory RealDef: better support for embedding natural numbers and
  5090 integers in the reals.
  5091 
  5092 The following theorems have been eliminated or modified
  5093 (INCOMPATIBILITY):
  5094 
  5095   exp_ge_add_one_self  now requires no hypotheses
  5096   real_of_int_add      reversed direction of equality (use [symmetric])
  5097   real_of_int_minus    reversed direction of equality (use [symmetric])
  5098   real_of_int_diff     reversed direction of equality (use [symmetric])
  5099   real_of_int_mult     reversed direction of equality (use [symmetric])
  5100 
  5101 * Theory RComplete: expanded support for floor and ceiling functions.
  5102 
  5103 * Theory Ln is new, with properties of the natural logarithm
  5104 
  5105 * Hyperreal: There is a new type constructor "star" for making
  5106 nonstandard types.  The old type names are now type synonyms:
  5107 
  5108   hypreal = real star
  5109   hypnat = nat star
  5110   hcomplex = complex star
  5111 
  5112 * Hyperreal: Many groups of similarly-defined constants have been
  5113 replaced by polymorphic versions (INCOMPATIBILITY):
  5114 
  5115   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5116 
  5117   starset      <-- starsetNat, starsetC
  5118   *s*          <-- *sNat*, *sc*
  5119   starset_n    <-- starsetNat_n, starsetC_n
  5120   *sn*         <-- *sNatn*, *scn*
  5121   InternalSets <-- InternalNatSets, InternalCSets
  5122 
  5123   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5124   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5125   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5126   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5127   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5128 
  5129 * Hyperreal: Many type-specific theorems have been removed in favor of
  5130 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5131 
  5132   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5133   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5134   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5135   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5136   right_minus <-- hypreal_add_minus
  5137   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5138   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5139   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5140   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5141   mult_1_right <-- hcomplex_mult_one_right
  5142   mult_zero_left <-- hcomplex_mult_zero_left
  5143   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5144   right_distrib <-- hypnat_add_mult_distrib2
  5145   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5146   right_inverse <-- hypreal_mult_inverse
  5147   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5148   order_refl <-- {hypreal,hypnat}_le_refl
  5149   order_trans <-- {hypreal,hypnat}_le_trans
  5150   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5151   order_less_le <-- {hypreal,hypnat}_less_le
  5152   linorder_linear <-- {hypreal,hypnat}_le_linear
  5153   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5154   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5155   add_nonneg_nonneg <-- hypreal_le_add_order
  5156 
  5157 * Hyperreal: Separate theorems having to do with type-specific
  5158 versions of constants have been merged into theorems that apply to the
  5159 new polymorphic constants (INCOMPATIBILITY):
  5160 
  5161   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5162   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5163   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5164   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5165   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5166   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5167   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5168   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5169   STAR_diff <-- {STAR,STARC}_diff
  5170   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5171     STARC_hcomplex_of_complex}_image_subset
  5172   starset_n_Un <-- starset{Nat,C}_n_Un
  5173   starset_n_Int <-- starset{Nat,C}_n_Int
  5174   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5175   starset_n_diff <-- starset{Nat,C}_n_diff
  5176   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5177   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5178   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5179   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5180   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5181   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5182   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5183   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5184   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5185   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5186   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5187   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5188   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5189   starfun_diff <-- starfun{C,RC,CR}_diff
  5190   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5191   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5192   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5193   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5194   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5195   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5196   starfun_Id <-- starfunC_Id
  5197   starfun_approx <-- starfun{Nat,CR}_approx
  5198   starfun_capprox <-- starfun{C,RC}_capprox
  5199   starfun_abs <-- starfunNat_rabs
  5200   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5201   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5202   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5203   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5204   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5205   starfun_add_approx <-- starfunCR_add_approx
  5206   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5207   starfun_divide <-- starfun{C,CR,RC}_divide
  5208   starfun_n <-- starfun{Nat,C}_n
  5209   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5210   starfun_n_add <-- starfun{Nat,C}_n_add
  5211   starfun_n_add_minus <-- starfunNat_n_add_minus
  5212   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5213   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5214   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5215 
  5216   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5217   star_n_minus <-- {hypreal,hcomplex}_minus
  5218   star_n_diff <-- {hypreal,hcomplex}_diff
  5219   star_n_mult <-- {hypreal,hcomplex}_mult
  5220   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5221   star_n_le <-- {hypreal,hypnat}_le
  5222   star_n_less <-- {hypreal,hypnat}_less
  5223   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5224   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5225   star_n_abs <-- hypreal_hrabs
  5226   star_n_divide <-- hcomplex_divide
  5227 
  5228   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5229   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5230   star_of_diff <-- hypreal_of_real_diff
  5231   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5232   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5233   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5234   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5235   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5236   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5237   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5238   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5239   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5240   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5241   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5242   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5243   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5244   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5245   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5246   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5247   star_of_power <-- hypreal_of_real_power
  5248   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5249 
  5250 * Hyperreal: new method "transfer" that implements the transfer
  5251 principle of nonstandard analysis. With a subgoal that mentions
  5252 nonstandard types like "'a star", the command "apply transfer"
  5253 replaces it with an equivalent one that mentions only standard types.
  5254 To be successful, all free variables must have standard types; non-
  5255 standard variables must have explicit universal quantifiers.
  5256 
  5257 * Hyperreal: A theory of Taylor series.
  5258 
  5259 
  5260 *** HOLCF ***
  5261 
  5262 * Discontinued special version of 'constdefs' (which used to support
  5263 continuous functions) in favor of the general Pure one with full
  5264 type-inference.
  5265 
  5266 * New simplification procedure for solving continuity conditions; it
  5267 is much faster on terms with many nested lambda abstractions (cubic
  5268 instead of exponential time).
  5269 
  5270 * New syntax for domain package: selector names are now optional.
  5271 Parentheses should be omitted unless argument is lazy, for example:
  5272 
  5273   domain 'a stream = cons "'a" (lazy "'a stream")
  5274 
  5275 * New command 'fixrec' for defining recursive functions with pattern
  5276 matching; defining multiple functions with mutual recursion is also
  5277 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5278 sinr, or any data constructor defined by the domain package. The given
  5279 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5280 syntax and examples.
  5281 
  5282 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5283 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5284 but the proof obligation additionally includes an admissibility
  5285 requirement. The packages generate instances of class cpo or pcpo,
  5286 with continuity and strictness theorems for Rep and Abs.
  5287 
  5288 * HOLCF: Many theorems have been renamed according to a more standard naming
  5289 scheme (INCOMPATIBILITY):
  5290 
  5291   foo_inject:  "foo$x = foo$y ==> x = y"
  5292   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5293   foo_less:    "(foo$x << foo$y) = (x << y)"
  5294   foo_strict:  "foo$UU = UU"
  5295   foo_defined: "... ==> foo$x ~= UU"
  5296   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5297 
  5298 
  5299 *** ZF ***
  5300 
  5301 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5302 including the First Isomorphism Theorem (on quotienting by the kernel
  5303 of a homomorphism).
  5304 
  5305 * ZF/Simplifier: install second copy of type solver that actually
  5306 makes use of TC rules declared to Isar proof contexts (or locales);
  5307 the old version is still required for ML proof scripts.
  5308 
  5309 
  5310 *** Cube ***
  5311 
  5312 * Converted to Isar theory format; use locales instead of axiomatic
  5313 theories.
  5314 
  5315 
  5316 *** ML ***
  5317 
  5318 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5319 for ||>, ||>>, |>>,
  5320 
  5321 * Pure/library.ML no longer defines its own option datatype, but uses
  5322 that of the SML basis, which has constructors NONE and SOME instead of
  5323 None and Some, as well as exception Option.Option instead of OPTION.
  5324 The functions the, if_none, is_some, is_none have been adapted
  5325 accordingly, while Option.map replaces apsome.
  5326 
  5327 * Pure/library.ML: the exception LIST has been given up in favour of
  5328 the standard exceptions Empty and Subscript, as well as
  5329 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5330 superceded by the standard hd and tl functions etc.
  5331 
  5332 A number of basic list functions are no longer exported to the ML
  5333 toplevel, as they are variants of predefined functions.  The following
  5334 suggests how one can translate existing code:
  5335 
  5336     rev_append xs ys = List.revAppend (xs, ys)
  5337     nth_elem (i, xs) = List.nth (xs, i)
  5338     last_elem xs = List.last xs
  5339     flat xss = List.concat xss
  5340     seq fs = List.app fs
  5341     partition P xs = List.partition P xs
  5342     mapfilter f xs = List.mapPartial f xs
  5343 
  5344 * Pure/library.ML: several combinators for linear functional
  5345 transformations, notably reverse application and composition:
  5346 
  5347   x |> f                f #> g
  5348   (x, y) |-> f          f #-> g
  5349 
  5350 * Pure/library.ML: introduced/changed precedence of infix operators:
  5351 
  5352   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5353   infix 2 ?;
  5354   infix 3 o oo ooo oooo;
  5355   infix 4 ~~ upto downto;
  5356 
  5357 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5358 infix operators.
  5359 
  5360 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5361 fold_map support linear functional transformations and nesting.  For
  5362 example:
  5363 
  5364   fold f [x1, ..., xN] y =
  5365     y |> f x1 |> ... |> f xN
  5366 
  5367   (fold o fold) f [xs1, ..., xsN] y =
  5368     y |> fold f xs1 |> ... |> fold f xsN
  5369 
  5370   fold f [x1, ..., xN] =
  5371     f x1 #> ... #> f xN
  5372 
  5373   (fold o fold) f [xs1, ..., xsN] =
  5374     fold f xs1 #> ... #> fold f xsN
  5375 
  5376 * Pure/library.ML: the following selectors on type 'a option are
  5377 available:
  5378 
  5379   the:               'a option -> 'a  (*partial*)
  5380   these:             'a option -> 'a  where 'a = 'b list
  5381   the_default: 'a -> 'a option -> 'a
  5382   the_list:          'a option -> 'a list
  5383 
  5384 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5385 basic operations for association lists, following natural argument
  5386 order; moreover the explicit equality predicate passed here avoids
  5387 potentially expensive polymorphic runtime equality checks.
  5388 The old functions may be expressed as follows:
  5389 
  5390   assoc = uncurry (AList.lookup (op =))
  5391   assocs = these oo AList.lookup (op =)
  5392   overwrite = uncurry (AList.update (op =)) o swap
  5393 
  5394 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5395 
  5396   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5397   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5398 
  5399 replacing make_keylist and keyfilter (occassionally used)
  5400 Naive rewrites:
  5401 
  5402   make_keylist = AList.make
  5403   keyfilter = AList.find (op =)
  5404 
  5405 * eq_fst and eq_snd now take explicit equality parameter, thus
  5406   avoiding eqtypes. Naive rewrites:
  5407 
  5408     eq_fst = eq_fst (op =)
  5409     eq_snd = eq_snd (op =)
  5410 
  5411 * Removed deprecated apl and apr (rarely used).
  5412   Naive rewrites:
  5413 
  5414     apl (n, op) =>>= curry op n
  5415     apr (op, m) =>>= fn n => op (n, m)
  5416 
  5417 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5418 provides a reasonably efficient light-weight implementation of sets as
  5419 lists.
  5420 
  5421 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5422 few new operations; existing lookup and update are now curried to
  5423 follow natural argument order (for use with fold etc.);
  5424 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5425 
  5426 * Pure/General: output via the Isabelle channels of
  5427 writeln/warning/error etc. is now passed through Output.output, with a
  5428 hook for arbitrary transformations depending on the print_mode
  5429 (cf. Output.add_mode -- the first active mode that provides a output
  5430 function wins).  Already formatted output may be embedded into further
  5431 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5432 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5433 accommodate easy composition of diagnostic messages etc.  Programmers
  5434 rarely need to care about Output.output or Output.raw at all, with
  5435 some notable exceptions: Output.output is required when bypassing the
  5436 standard channels (writeln etc.), or in token translations to produce
  5437 properly formatted results; Output.raw is required when capturing
  5438 already output material that will eventually be presented to the user
  5439 a second time.  For the default print mode, both Output.output and
  5440 Output.raw have no effect.
  5441 
  5442 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5443 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5444 cumulative results are displayed at the end of a batch session.
  5445 
  5446 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5447 replaced by File.platform_path and File.shell_path (with appropriate
  5448 hooks).  This provides a clean interface for unusual systems where the
  5449 internal and external process view of file names are different.
  5450 
  5451 * Pure: more efficient orders for basic syntactic entities: added
  5452 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5453 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5454 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5455 orders now -- potential INCOMPATIBILITY for code that depends on a
  5456 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5457 Library.sort_strings on result).
  5458 
  5459 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5460 fold_types traverse types/terms from left to right, observing natural
  5461 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5462 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5463 
  5464 * Pure: name spaces have been refined, with significant changes of the
  5465 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5466 to extern(_table).  The plain name entry path is superceded by a
  5467 general 'naming' context, which also includes the 'policy' to produce
  5468 a fully qualified name and external accesses of a fully qualified
  5469 name; NameSpace.extend is superceded by context dependent
  5470 Sign.declare_name.  Several theory and proof context operations modify
  5471 the naming context.  Especially note Theory.restore_naming and
  5472 ProofContext.restore_naming to get back to a sane state; note that
  5473 Theory.add_path is no longer sufficient to recover from
  5474 Theory.absolute_path in particular.
  5475 
  5476 * Pure: new flags short_names (default false) and unique_names
  5477 (default true) for controlling output of qualified names.  If
  5478 short_names is set, names are printed unqualified.  If unique_names is
  5479 reset, the name prefix is reduced to the minimum required to achieve
  5480 the original result when interning again, even if there is an overlap
  5481 with earlier declarations.
  5482 
  5483 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5484 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5485 (useful for printing error messages).  INCOMPATIBILITY.
  5486 
  5487 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5488 Theory.theory are now identified, referring to the universal
  5489 Context.theory (see Pure/context.ML).  Actual signature and theory
  5490 content is managed as theory data.  The old code and interfaces were
  5491 spread over many files and structures; the new arrangement introduces
  5492 considerable INCOMPATIBILITY to gain more clarity:
  5493 
  5494   Context -- theory management operations (name, identity, inclusion,
  5495     parents, ancestors, merge, etc.), plus generic theory data;
  5496 
  5497   Sign -- logical signature and syntax operations (declaring consts,
  5498     types, etc.), plus certify/read for common entities;
  5499 
  5500   Theory -- logical theory operations (stating axioms, definitions,
  5501     oracles), plus a copy of logical signature operations (consts,
  5502     types, etc.); also a few basic management operations (Theory.copy,
  5503     Theory.merge, etc.)
  5504 
  5505 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5506 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5507 for convenience -- they merely return the theory.
  5508 
  5509 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5510 
  5511 * Pure: the Isar proof context type is already defined early in Pure
  5512 as Context.proof (note that ProofContext.context and Proof.context are
  5513 aliases, where the latter is the preferred name).  This enables other
  5514 Isabelle components to refer to that type even before Isar is present.
  5515 
  5516 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5517 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5518 any of these kinds.  For example, Sign.intern typeK is now
  5519 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5520 Theory.hide_types.  Also note that former
  5521 Theory.hide_classes/types/consts are now
  5522 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5523 internalize their arguments!  INCOMPATIBILITY.
  5524 
  5525 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5526 datatype thmref (with constructors Name and NameSelection) instead of
  5527 plain string -- INCOMPATIBILITY;
  5528 
  5529 * Pure: cases produced by proof methods specify options, where NONE
  5530 means to remove case bindings -- INCOMPATIBILITY in
  5531 (RAW_)METHOD_CASES.
  5532 
  5533 * Pure: the following operations retrieve axioms or theorems from a
  5534 theory node or theory hierarchy, respectively:
  5535 
  5536   Theory.axioms_of: theory -> (string * term) list
  5537   Theory.all_axioms_of: theory -> (string * term) list
  5538   PureThy.thms_of: theory -> (string * thm) list
  5539   PureThy.all_thms_of: theory -> (string * thm) list
  5540 
  5541 * Pure: print_tac now outputs the goal through the trace channel.
  5542 
  5543 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5544 Reference Toplevel.debug (default false) controls detailed printing
  5545 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5546 controls execution profiling -- set to 1 for time and 2 for space
  5547 (both increase the runtime).
  5548 
  5549 * Isar session: The initial use of ROOT.ML is now always timed,
  5550 i.e. the log will show the actual process times, in contrast to the
  5551 elapsed wall-clock time that the outer shell wrapper produces.
  5552 
  5553 * Simplifier: improved handling of bound variables (nameless
  5554 representation, avoid allocating new strings).  Simprocs that invoke
  5555 the Simplifier recursively should use Simplifier.inherit_bounds to
  5556 avoid local name clashes.  Failure to do so produces warnings
  5557 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5558 for further details.
  5559 
  5560 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5561 bindings for all theorems stored within a given theory; this may help
  5562 in porting non-Isar theories to Isar ones, while keeping ML proof
  5563 scripts for the time being.
  5564 
  5565 * ML operator HTML.with_charset specifies the charset begin used for
  5566 generated HTML files.  For example:
  5567 
  5568   HTML.with_charset "utf-8" use_thy "Hebrew";
  5569   HTML.with_charset "utf-8" use_thy "Chinese";
  5570 
  5571 
  5572 *** System ***
  5573 
  5574 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5575 isabelle, isatool etc.).
  5576 
  5577 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5578 isatool doc, isatool mkdir, display_drafts etc.).
  5579 
  5580 * isatool usedir: option -f allows specification of the ML file to be
  5581 used by Isabelle; default is ROOT.ML.
  5582 
  5583 * New isatool version outputs the version identifier of the Isabelle
  5584 distribution being used.
  5585 
  5586 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5587 (containing Boolean satisfiability problems) into Isabelle/HOL
  5588 theories.
  5589 
  5590 
  5591 
  5592 New in Isabelle2004 (April 2004)
  5593 --------------------------------
  5594 
  5595 *** General ***
  5596 
  5597 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5598   Replaces linorder.ML.
  5599 
  5600 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5601   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5602   (\<a>...\<z>), are now considered normal letters, and can therefore
  5603   be used anywhere where an ASCII letter (a...zA...Z) has until
  5604   now. COMPATIBILITY: This obviously changes the parsing of some
  5605   terms, especially where a symbol has been used as a binder, say
  5606   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5607   as an identifier.  Fix it by inserting a space around former
  5608   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5609   existing theory and ML files.
  5610 
  5611 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5612 
  5613 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5614   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5615   a normal (but invisible) letter. For multiple letter subscripts repeat
  5616   \<^isub> like this: x\<^isub>1\<^isub>2.
  5617 
  5618 * Pure: There are now sub-/superscripts that can span more than one
  5619   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5620   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5621   superscript. The new control characters are not identifier parts.
  5622 
  5623 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5624   content of "..." to the latex file instead of \isacntrl... . The "..."
  5625   may consist of any printable characters excluding the end bracket >.
  5626 
  5627 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5628   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5629   declare constants "final", which prevents their being given a definition
  5630   later.  It is useful for constants whose behaviour is fixed axiomatically
  5631   rather than definitionally, such as the meta-logic connectives.
  5632 
  5633 * Pure: 'instance' now handles general arities with general sorts
  5634   (i.e. intersections of classes),
  5635 
  5636 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5637   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5638   It can be changed to alter the colors/layout of generated pages.
  5639 
  5640 
  5641 *** Isar ***
  5642 
  5643 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5644   cut_tac, subgoal_tac and thin_tac:
  5645   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5646     locales are no longer forced to write Isar proof scripts.
  5647     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5648     emulations.
  5649   - INCOMPATIBILITY: names of variables to be instantiated may no
  5650     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5651     This is consistent with the instantiation attribute "where".
  5652 
  5653 * Attributes "where" and "of":
  5654   - Now take type variables of instantiated theorem into account when reading
  5655     the instantiation string.  This fixes a bug that caused instantiated
  5656     theorems to have too special types in some circumstances.
  5657   - "where" permits explicit instantiations of type variables.
  5658 
  5659 * Calculation commands "moreover" and "also" no longer interfere with
  5660   current facts ("this"), admitting arbitrary combinations with "then"
  5661   and derived forms.
  5662 
  5663 * Locales:
  5664   - Goal statements involving the context element "includes" no longer
  5665     generate theorems with internal delta predicates (those ending on
  5666     "_axioms") in the premise.
  5667     Resolve particular premise with <locale>.intro to obtain old form.
  5668   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5669     specification and "includes" elements in goal statement.
  5670   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5671     [intro?] and [elim?] (respectively) by default.
  5672   - Experimental command for instantiation of locales in proof contexts:
  5673         instantiate <label>[<attrs>]: <loc>
  5674     Instantiates locale <loc> and adds all its theorems to the current context
  5675     taking into account their attributes.  Label and attrs are optional
  5676     modifiers, like in theorem declarations.  If present, names of
  5677     instantiated theorems are qualified with <label>, and the attributes
  5678     <attrs> are applied after any attributes these theorems might have already.
  5679       If the locale has assumptions, a chained fact of the form
  5680     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5681     are derived.  The command does not support old-style locales declared
  5682     with "locale (open)".
  5683       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5684 
  5685 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5686   (Isar) contexts.
  5687 
  5688 
  5689 *** HOL ***
  5690 
  5691 * Proof import: new image HOL4 contains the imported library from
  5692   the HOL4 system with about 2500 theorems. It is imported by
  5693   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5694   can be used like any other Isabelle image.  See
  5695   HOL/Import/HOL/README for more information.
  5696 
  5697 * Simplifier:
  5698   - Much improved handling of linear and partial orders.
  5699     Reasoners for linear and partial orders are set up for type classes
  5700     "linorder" and "order" respectively, and are added to the default simpset
  5701     as solvers.  This means that the simplifier can build transitivity chains
  5702     to solve goals from the assumptions.
  5703   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5704     of blast or auto after simplification become unnecessary because the goal
  5705     is solved by simplification already.
  5706 
  5707 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5708     all proved in axiomatic type classes for semirings, rings and fields.
  5709 
  5710 * Numerics:
  5711   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5712     now formalized using the Ring_and_Field theory mentioned above.
  5713   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5714     than before, because now they are set up once in a generic manner.
  5715   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5716     Look for the general versions in Ring_and_Field (and Power if they concern
  5717     exponentiation).
  5718 
  5719 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5720 
  5721 * Records:
  5722   - Record types are now by default printed with their type abbreviation
  5723     instead of the list of all field types. This can be configured via
  5724     the reference "print_record_type_abbr".
  5725   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5726     (not enabled by default).
  5727   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5728     EX x. x = sel r to True (not enabled by default).
  5729   - Tactic "record_split_simp_tac" to split and simplify records added.
  5730 
  5731 * 'specification' command added, allowing for definition by
  5732   specification.  There is also an 'ax_specification' command that
  5733   introduces the new constants axiomatically.
  5734 
  5735 * arith(_tac) is now able to generate counterexamples for reals as well.
  5736 
  5737 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5738 
  5739 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5740   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5741 
  5742 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5743   matrix theory to linear programming.
  5744 
  5745 * Unions and Intersections:
  5746   The latex output syntax of UN and INT has been changed
  5747   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5748   i.e. the index formulae has become a subscript.
  5749   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5750 
  5751 * Unions and Intersections over Intervals:
  5752   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5753   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5754   like in normal math, and corresponding versions for < and for intersection.
  5755 
  5756 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5757   lexicographic dictonary ordering has been added as "lexord".
  5758 
  5759 * ML: the legacy theory structures Int and List have been removed. They had
  5760   conflicted with ML Basis Library structures having the same names.
  5761 
  5762 * 'refute' command added to search for (finite) countermodels.  Only works
  5763   for a fragment of HOL.  The installation of an external SAT solver is
  5764   highly recommended.  See "HOL/Refute.thy" for details.
  5765 
  5766 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5767   formulae under an assignment of free variables to random values.
  5768   In contrast to 'refute', it can deal with inductive datatypes,
  5769   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5770   for examples.
  5771 
  5772 
  5773 *** HOLCF ***
  5774 
  5775 * Streams now come with concatenation and are part of the HOLCF image
  5776 
  5777 
  5778 
  5779 New in Isabelle2003 (May 2003)
  5780 ------------------------------
  5781 
  5782 *** General ***
  5783 
  5784 * Provers/simplifier:
  5785 
  5786   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5787     Assumptions are now subject to complete mutual simplification,
  5788     not just from left to right. The simplifier now preserves
  5789     the order of assumptions.
  5790 
  5791     Potential INCOMPATIBILITY:
  5792 
  5793     -- simp sometimes diverges where the old version did
  5794        not, e.g. invoking simp on the goal
  5795 
  5796         [| P (f x); y = x; f x = f y |] ==> Q
  5797 
  5798        now gives rise to the infinite reduction sequence
  5799 
  5800         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5801 
  5802        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5803        kind of problem.
  5804 
  5805     -- Tactics combining classical reasoner and simplification (such as auto)
  5806        are also affected by this change, because many of them rely on
  5807        simp. They may sometimes diverge as well or yield a different numbers
  5808        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5809        in case of problems. Sometimes subsequent calls to the classical
  5810        reasoner will fail because a preceeding call to the simplifier too
  5811        eagerly simplified the goal, e.g. deleted redundant premises.
  5812 
  5813   - The simplifier trace now shows the names of the applied rewrite rules
  5814 
  5815   - You can limit the number of recursive invocations of the simplifier
  5816     during conditional rewriting (where the simplifie tries to solve the
  5817     conditions before applying the rewrite rule):
  5818     ML "simp_depth_limit := n"
  5819     where n is an integer. Thus you can force termination where previously
  5820     the simplifier would diverge.
  5821 
  5822   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5823 
  5824   - No longer aborts on failed congruence proof.  Instead, the
  5825     congruence is ignored.
  5826 
  5827 * Pure: New generic framework for extracting programs from constructive
  5828   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5829   as HOL/Extraction for some case studies.
  5830 
  5831 * Pure: The main goal of the proof state is no longer shown by default, only
  5832 the subgoals. This behaviour is controlled by a new flag.
  5833    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5834 (ML: Proof.show_main_goal).
  5835 
  5836 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5837 rules whose conclusion matches subgoal 1:
  5838       PG menu: Isabelle/Isar -> Show me -> matching rules
  5839 The rules are ordered by how closely they match the subgoal.
  5840 In particular, rules that solve a subgoal outright are displayed first
  5841 (or rather last, the way they are printed).
  5842 (ML: ProofGeneral.print_intros())
  5843 
  5844 * Pure: New flag trace_unify_fail causes unification to print
  5845 diagnostic information (PG: in trace buffer) when it fails. This is
  5846 useful for figuring out why single step proofs like rule, erule or
  5847 assumption failed.
  5848 
  5849 * Pure: Locale specifications now produce predicate definitions
  5850 according to the body of text (covering assumptions modulo local
  5851 definitions); predicate "loc_axioms" covers newly introduced text,
  5852 while "loc" is cumulative wrt. all included locale expressions; the
  5853 latter view is presented only on export into the global theory
  5854 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5855 on the old view without predicates;
  5856 
  5857 * Pure: predefined locales "var" and "struct" are useful for sharing
  5858 parameters (as in CASL, for example); just specify something like
  5859 ``var x + var y + struct M'' as import;
  5860 
  5861 * Pure: improved thms_containing: proper indexing of facts instead of
  5862 raw theorems; check validity of results wrt. current name space;
  5863 include local facts of proof configuration (also covers active
  5864 locales), cover fixed variables in index; may use "_" in term
  5865 specification; an optional limit for the number of printed facts may
  5866 be given (the default is 40);
  5867 
  5868 * Pure: disallow duplicate fact bindings within new-style theory files
  5869 (batch-mode only);
  5870 
  5871 * Provers: improved induct method: assumptions introduced by case
  5872 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5873 the goal statement); "foo" still refers to all facts collectively;
  5874 
  5875 * Provers: the function blast.overloaded has been removed: all constants
  5876 are regarded as potentially overloaded, which improves robustness in exchange
  5877 for slight decrease in efficiency;
  5878 
  5879 * Provers/linorder: New generic prover for transitivity reasoning over
  5880 linear orders.  Note: this prover is not efficient!
  5881 
  5882 * Isar: preview of problems to finish 'show' now produce an error
  5883 rather than just a warning (in interactive mode);
  5884 
  5885 
  5886 *** HOL ***
  5887 
  5888 * arith(_tac)
  5889 
  5890  - Produces a counter example if it cannot prove a goal.
  5891    Note that the counter example may be spurious if the goal is not a formula
  5892    of quantifier-free linear arithmetic.
  5893    In ProofGeneral the counter example appears in the trace buffer.
  5894 
  5895  - Knows about div k and mod k where k is a numeral of type nat or int.
  5896 
  5897  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5898    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5899    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5900 
  5901 * simp's arithmetic capabilities have been enhanced a bit: it now
  5902 takes ~= in premises into account (by performing a case split);
  5903 
  5904 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5905 are distributed over a sum of terms;
  5906 
  5907 * New tactic "trans_tac" and method "trans" instantiate
  5908 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5909 "<=", "<" and "=").
  5910 
  5911 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5912 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5913 
  5914 * 'typedef' command has new option "open" to suppress the set
  5915 definition;
  5916 
  5917 * functions Min and Max on finite sets have been introduced (theory
  5918 Finite_Set);
  5919 
  5920 * attribute [symmetric] now works for relations as well; it turns
  5921 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5922 
  5923 * induct over a !!-quantified statement (say !!x1..xn):
  5924   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5925 
  5926 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5927 %x. None. Warning: empty_def now refers to the previously hidden definition
  5928 of the empty set.
  5929 
  5930 * Algebra: formalization of classical algebra.  Intended as base for
  5931 any algebraic development in Isabelle.  Currently covers group theory
  5932 (up to Sylow's theorem) and ring theory (Universal Property of
  5933 Univariate Polynomials).  Contributions welcome;
  5934 
  5935 * GroupTheory: deleted, since its material has been moved to Algebra;
  5936 
  5937 * Complex: new directory of the complex numbers with numeric constants,
  5938 nonstandard complex numbers, and some complex analysis, standard and
  5939 nonstandard (Jacques Fleuriot);
  5940 
  5941 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5942 
  5943 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5944 Fleuriot);
  5945 
  5946 * Real/HahnBanach: updated and adapted to locales;
  5947 
  5948 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5949 Gray and Kramer);
  5950 
  5951 * UNITY: added the Meier-Sanders theory of progress sets;
  5952 
  5953 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5954 as abstract algorithms, instantiated to the JVM;
  5955 
  5956 * Bali: Java source language formalization. Type system, operational
  5957 semantics, axiomatic semantics. Supported language features:
  5958 classes, interfaces, objects,virtual methods, static methods,
  5959 static/instance fields, arrays, access modifiers, definite
  5960 assignment, exceptions.
  5961 
  5962 
  5963 *** ZF ***
  5964 
  5965 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5966 universe, etc.);
  5967 
  5968 * Main ZF: virtually all theories converted to new-style format;
  5969 
  5970 
  5971 *** ML ***
  5972 
  5973 * Pure: Tactic.prove provides sane interface for internal proofs;
  5974 omits the infamous "standard" operation, so this is more appropriate
  5975 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5976 
  5977 * Pure: improved error reporting of simprocs;
  5978 
  5979 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5980 up simprocs;
  5981 
  5982 
  5983 *** Document preparation ***
  5984 
  5985 * uses \par instead of \\ for line breaks in theory text. This may
  5986 shift some page breaks in large documents. To get the old behaviour
  5987 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5988 
  5989 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5990 other packages
  5991 
  5992 * \<euro> now needs package babel/greek instead of marvosym (which
  5993 broke \Rightarrow)
  5994 
  5995 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5996 textcomp package)
  5997 
  5998 
  5999 
  6000 New in Isabelle2002 (March 2002)
  6001 --------------------------------
  6002 
  6003 *** Document preparation ***
  6004 
  6005 * greatly simplified document preparation setup, including more
  6006 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6007 instructive isatool mkdir; users should basically be able to get
  6008 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6009 users may run a separate document processing stage manually like this:
  6010 "isatool usedir -D output HOL Test && isatool document Test/output";
  6011 
  6012 * theory dependency graph may now be incorporated into documents;
  6013 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6014 with \includegraphics of LaTeX;
  6015 
  6016 * proper spacing of consecutive markup elements, especially text
  6017 blocks after section headings;
  6018 
  6019 * support bold style (for single symbols only), input syntax is like
  6020 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6021 
  6022 * \<bullet> is now output as bold \cdot by default, which looks much
  6023 better in printed text;
  6024 
  6025 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6026 note that these symbols are currently unavailable in Proof General /
  6027 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6028 
  6029 * isatool latex no longer depends on changed TEXINPUTS, instead
  6030 isatool document copies the Isabelle style files to the target
  6031 location;
  6032 
  6033 
  6034 *** Isar ***
  6035 
  6036 * Pure/Provers: improved proof by cases and induction;
  6037   - 'case' command admits impromptu naming of parameters (such as
  6038     "case (Suc n)");
  6039   - 'induct' method divinates rule instantiation from the inductive
  6040     claim; no longer requires excessive ?P bindings for proper
  6041     instantiation of cases;
  6042   - 'induct' method properly enumerates all possibilities of set/type
  6043     rules; as a consequence facts may be also passed through *type*
  6044     rules without further ado;
  6045   - 'induct' method now derives symbolic cases from the *rulified*
  6046     rule (before it used to rulify cases stemming from the internal
  6047     atomized version); this means that the context of a non-atomic
  6048     statement becomes is included in the hypothesis, avoiding the
  6049     slightly cumbersome show "PROP ?case" form;
  6050   - 'induct' may now use elim-style induction rules without chaining
  6051     facts, using ``missing'' premises from the goal state; this allows
  6052     rules stemming from inductive sets to be applied in unstructured
  6053     scripts, while still benefitting from proper handling of non-atomic
  6054     statements; NB: major inductive premises need to be put first, all
  6055     the rest of the goal is passed through the induction;
  6056   - 'induct' proper support for mutual induction involving non-atomic
  6057     rule statements (uses the new concept of simultaneous goals, see
  6058     below);
  6059   - append all possible rule selections, but only use the first
  6060     success (no backtracking);
  6061   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6062   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6063   - added 'print_induct_rules' (covered by help item in recent Proof
  6064     General versions);
  6065   - moved induct/cases attributes to Pure, methods to Provers;
  6066   - generic method setup instantiated for FOL and HOL;
  6067 
  6068 * Pure: support multiple simultaneous goal statements, for example
  6069 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6070 meta-level mechanism, this acts as if several individual goals had
  6071 been stated separately; in particular common proof methods need to be
  6072 repeated in order to cover all claims; note that a single elimination
  6073 step is *not* sufficient to establish the two conjunctions, so this
  6074 fails:
  6075 
  6076   assume "A & B" then have A and B ..   (*".." fails*)
  6077 
  6078 better use "obtain" in situations as above; alternative refer to
  6079 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6080 
  6081 * Pure: proper integration with ``locales''; unlike the original
  6082 version by Florian Kammller, Isar locales package high-level proof
  6083 contexts rather than raw logical ones (e.g. we admit to include
  6084 attributes everywhere); operations on locales include merge and
  6085 rename; support for implicit arguments (``structures''); simultaneous
  6086 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6087 some examples;
  6088 
  6089 * Pure: the following commands have been ``localized'', supporting a
  6090 target locale specification "(in name)": 'lemma', 'theorem',
  6091 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6092 stored both within the locale and at the theory level (exported and
  6093 qualified by the locale name);
  6094 
  6095 * Pure: theory goals may now be specified in ``long'' form, with
  6096 ad-hoc contexts consisting of arbitrary locale elements. for example
  6097 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6098 definitions may be given, too); the result is a meta-level rule with
  6099 the context elements being discharged in the obvious way;
  6100 
  6101 * Pure: new proof command 'using' allows to augment currently used
  6102 facts after a goal statement ('using' is syntactically analogous to
  6103 'apply', but acts on the goal's facts only); this allows chained facts
  6104 to be separated into parts given before and after a claim, as in
  6105 ``from a and b have C using d and e <proof>'';
  6106 
  6107 * Pure: renamed "antecedent" case to "rule_context";
  6108 
  6109 * Pure: new 'judgment' command records explicit information about the
  6110 object-logic embedding (used by several tools internally); no longer
  6111 use hard-wired "Trueprop";
  6112 
  6113 * Pure: added 'corollary' command;
  6114 
  6115 * Pure: fixed 'token_translation' command;
  6116 
  6117 * Pure: removed obsolete 'exported' attribute;
  6118 
  6119 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6120 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6121 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6122 
  6123 * Pure: method 'atomize' presents local goal premises as object-level
  6124 statements (atomic meta-level propositions); setup controlled via
  6125 rewrite rules declarations of 'atomize' attribute; example
  6126 application: 'induct' method with proper rule statements in improper
  6127 proof *scripts*;
  6128 
  6129 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6130 now consider the syntactic context of assumptions, giving a better
  6131 chance to get type-inference of the arguments right (this is
  6132 especially important for locales);
  6133 
  6134 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6135 mode;
  6136 
  6137 * Pure/obtain: the formal conclusion "thesis", being marked as
  6138 ``internal'', may no longer be reference directly in the text;
  6139 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6140 situations;
  6141 
  6142 * Pure: generic 'sym' attribute which declares a rule both as pure
  6143 'elim?' and for the 'symmetric' operation;
  6144 
  6145 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6146 text; the fixed correlation with particular command syntax has been
  6147 discontinued;
  6148 
  6149 * Pure: new method 'rules' is particularly well-suited for proof
  6150 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6151 but often produces more compact proof terms with less detours;
  6152 
  6153 * Pure/Provers/classical: simplified integration with pure rule
  6154 attributes and methods; the classical "intro?/elim?/dest?"
  6155 declarations coincide with the pure ones; the "rule" method no longer
  6156 includes classically swapped intros; "intro" and "elim" methods no
  6157 longer pick rules from the context; also got rid of ML declarations
  6158 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6159 INCOMPATIBILITY;
  6160 
  6161 * Provers/classical: attribute 'swapped' produces classical inversions
  6162 of introduction rules;
  6163 
  6164 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6165 rules instead of full simplifier context; 'iff' attribute handles
  6166 conditional rules;
  6167 
  6168 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6169 
  6170 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6171 "(permissive)" option to recover old behavior;
  6172 
  6173 * HOL: 'inductive' no longer features separate (collective) attributes
  6174 for 'intros' (was found too confusing);
  6175 
  6176 * HOL: properly declared induction rules less_induct and
  6177 wf_induct_rule;
  6178 
  6179 
  6180 *** HOL ***
  6181 
  6182 * HOL: moved over to sane numeral syntax; the new policy is as
  6183 follows:
  6184 
  6185   - 0 and 1 are polymorphic constants, which are defined on any
  6186   numeric type (nat, int, real etc.);
  6187 
  6188   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6189   binary representation internally;
  6190 
  6191   - type nat has special constructor Suc, and generally prefers Suc 0
  6192   over 1::nat and Suc (Suc 0) over 2::nat;
  6193 
  6194 This change may cause significant problems of INCOMPATIBILITY; here
  6195 are some hints on converting existing sources:
  6196 
  6197   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6198   entities, so expressions involving "-" (unary or binary minus) need
  6199   to be spaced properly;
  6200 
  6201   - existing occurrences of "1" may need to be constraint "1::nat" or
  6202   even replaced by Suc 0; similar for old "2";
  6203 
  6204   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6205 
  6206   - remove all special provisions on numerals in proofs;
  6207 
  6208 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6209 representation (depends on bin_arith_simps in the default context);
  6210 
  6211 * HOL: symbolic syntax for x^2 (numeral 2);
  6212 
  6213 * HOL: the class of all HOL types is now called "type" rather than
  6214 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6215 in axclass/classes, instance/arities, and (usually rare) occurrences
  6216 in typings (of consts etc.); internally the class is called
  6217 "HOL.type", ML programs should refer to HOLogic.typeS;
  6218 
  6219 * HOL/record package improvements:
  6220   - new derived operations "fields" to build a partial record section,
  6221     "extend" to promote a fixed record to a record scheme, and
  6222     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6223     declared as simp by default;
  6224   - shared operations ("more", "fields", etc.) now need to be always
  6225     qualified) --- potential INCOMPATIBILITY;
  6226   - removed "make_scheme" operations (use "make" with "extend") --
  6227     INCOMPATIBILITY;
  6228   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6229   - provides cases/induct rules for use with corresponding Isar
  6230     methods (for concrete records, record schemes, concrete more
  6231     parts, and sc