NEWS
author wenzelm
Fri Jul 08 16:13:34 2011 +0200 (2011-07-08)
changeset 43709 717e96cf9527
parent 43627 ecd4bb7a8bc0
child 43731 70072780e095
child 43736 d2f7af6e993c
permissions -rw-r--r--
discontinued special treatment of hard tabulators;
     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) has been discontinued.
    26 Note that the path element ~~ may be used to reference theories in the
    27 Isabelle home folder -- for instance, "~~/src/HOL/Library/FuncSet".
    28 INCOMPATIBILITY.
    29 
    30 * Various optional external tools are referenced more robustly and
    31 uniformly by explicit Isabelle settings as follows:
    32 
    33   ISABELLE_CSDP   (formerly CSDP_EXE)
    34   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
    35   ISABELLE_OCAML  (formerly EXEC_OCAML)
    36   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
    37   ISABELLE_YAP    (formerly EXEC_YAP)
    38 
    39 Note that automated detection from the file-system or search path has
    40 been discontinued.  INCOMPATIBILITY.
    41 
    42 * Name space: former unsynchronized references are now proper
    43 configuration options, with more conventional names:
    44 
    45   long_names   ~> names_long
    46   short_names  ~> names_short
    47   unique_names ~> names_unique
    48 
    49 Minor INCOMPATIBILITY, need to declare options in context like this:
    50 
    51   declare [[names_unique = false]]
    52 
    53 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
    54 that the result needs to be unique, which means fact specifications
    55 may have to be refined after enriching a proof context.
    56 
    57 * Isabelle/Isar reference manual provides more formal references in
    58 syntax diagrams.
    59 
    60 
    61 *** HOL ***
    62 
    63 * Finite_Set.thy: more coherent development of fold_set locales:
    64 
    65     locale fun_left_comm ~> locale comp_fun_commute
    66     locale fun_left_comm_idem ~> locale comp_fun_idem
    67     
    68 Both use point-free characterisation; interpretation proofs may need adjustment.
    69 INCOMPATIBILITY.
    70 
    71 * Code generation:
    72   - theory Library/Code_Char_ord provides native ordering of characters
    73     in the target language.
    74     
    75 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
    76 
    77 * Nitpick:
    78   - Added "need" and "total_consts" options.
    79   - Reintroduced "show_skolems" option by popular demand.
    80   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    81     INCOMPATIBILITY.
    82 
    83 * Sledgehammer:
    84   - sledgehammer available_provers ~> sledgehammer supported_provers.
    85     INCOMPATIBILITY.
    86   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
    87     TPTP problems (TFF).
    88   - Added "preplay_timeout", "slicing", "type_enc", "sound", "max_mono_iters",
    89     and "max_new_mono_instances" options.
    90   - Removed "explicit_apply" and "full_types" options as well as "Full Types"
    91     Proof General menu item. INCOMPATIBILITY.
    92 
    93 * Metis:
    94   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
    95   - Obsoleted "metisFT" -- use "metis (full_types)" instead. INCOMPATIBILITY.
    96 
    97 * "try":
    98   - Renamed "try_methods" and added "simp:", "intro:", "dest:", and "elim:"
    99     options. INCOMPATIBILITY.
   100   - Introduced "try" that not only runs "try_methods" but also "solve_direct",
   101     "sledgehammer", "quickcheck", and "nitpick".
   102 
   103 * Quickcheck:
   104   - Added "eval" option to evaluate terms for the found counterexample
   105     (currently only supported by the default (exhaustive) tester)
   106   - Added post-processing of terms to obtain readable counterexamples
   107     (currently only supported by the default (exhaustive) tester)
   108   - New counterexample generator quickcheck[narrowing] enables
   109     narrowing-based testing.
   110     It requires that the Glasgow Haskell compiler is installed and
   111     its location is known to Isabelle with the environment variable
   112     ISABELLE_GHC.
   113 
   114 * Function package: discontinued option "tailrec".
   115 INCOMPATIBILITY. Use partial_function instead.
   116 
   117 * HOL-Probability:
   118   - Caratheodory's extension lemma is now proved for ring_of_sets.
   119   - Infinite products of probability measures are now available.
   120   - Use extended reals instead of positive extended reals.
   121     INCOMPATIBILITY.
   122 
   123 
   124 *** Document preparation ***
   125 
   126 * Discontinued special treatment of hard tabulators, which are better
   127 avoided in the first place.  Implicit tab-width is 1.
   128 
   129 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   130 isar-ref manual.
   131 
   132 * Antiquotation @{value} evaluates the given term and presents its result.
   133 
   134 * Localized \isabellestyle switch can be used within blocks or groups
   135 like this:
   136 
   137   \isabellestyle{it}  %preferred default
   138   {\isabellestylett @{text "typewriter stuff"}}
   139 
   140 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   141 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   142 
   143 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   144 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   145 
   146 
   147 *** ML ***
   148 
   149 * Antiquotations for ML and document preparation are managed as theory
   150 data, which requires explicit setup.
   151 
   152 * Isabelle_Process.is_active allows tools to check if the official
   153 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
   154 (better known as Proof General).
   155 
   156 * Structure Proof_Context follows standard naming scheme.  Old
   157 ProofContext is still available for some time as legacy alias.
   158 
   159 * Structure Timing provides various operations for timing; supersedes
   160 former start_timing/end_timing etc.
   161 
   162 * Path.print is the official way to show file-system paths to users
   163 (including quotes etc.).
   164 
   165 * Inner syntax: identifiers in parse trees of generic categories
   166 "logic", "aprop", "idt" etc. carry position information (disguised as
   167 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   168 translations that choke on unexpected type constraints.  Positions can
   169 be stripped in ML translations via Syntax.strip_positions /
   170 Syntax.strip_positions_ast, or via the syntax constant
   171 "_strip_positions" within parse trees.  As last resort, positions can
   172 be disabled via the configuration option Syntax.positions, which is
   173 called "syntax_positions" in Isar attribute syntax.
   174 
   175 * Discontinued special status of various ML structures that contribute
   176 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   177 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   178 refer directly to Ast.Constant, Lexicon.is_identifier,
   179 Syntax_Trans.mk_binder_tr etc.
   180 
   181 * Typed print translation: discontinued show_sorts argument, which is
   182 already available via context of "advanced" translation.
   183 
   184 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   185 goal states; body tactic needs to address all subgoals uniformly.
   186 
   187 * Slightly more special eq_list/eq_set, with shortcut involving
   188 pointer equality (assumes that eq relation is reflexive).
   189 
   190 * Classical tactics use proper Proof.context instead of historic types
   191 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   192 operate directly on Proof.context.  Raw type claset retains its use as
   193 snapshot of the classical context, which can be recovered via
   194 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   195 INCOMPATIBILITY, classical tactics and derived proof methods require
   196 proper Proof.context.
   197 
   198 
   199 
   200 New in Isabelle2011 (January 2011)
   201 ----------------------------------
   202 
   203 *** General ***
   204 
   205 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   206 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   207 useful tooltips and hyperlinks produced from its static analysis.  The
   208 bundled component provides an executable Isabelle tool that can be run
   209 like this:
   210 
   211   Isabelle2011/bin/isabelle jedit
   212 
   213 * Significantly improved Isabelle/Isar implementation manual.
   214 
   215 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   216 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   217 while the default heap location within that directory lacks that extra
   218 suffix.  This isolates multiple Isabelle installations from each
   219 other, avoiding problems with old settings in new versions.
   220 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   221 
   222 * Source files are always encoded as UTF-8, instead of old-fashioned
   223 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   224 the following package declarations:
   225 
   226   \usepackage[utf8]{inputenc}
   227   \usepackage{textcomp}
   228 
   229 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   230 a Unicode character is treated as a single symbol, not a sequence of
   231 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   232 contain symbols without further backslash escapes, Unicode can now be
   233 used here as well.  Recall that Symbol.explode in ML provides a
   234 consistent view on symbols, while raw explode (or String.explode)
   235 merely give a byte-oriented representation.
   236 
   237 * Theory loader: source files are primarily located via the master
   238 directory of each theory node (where the .thy file itself resides).
   239 The global load path is still partially available as legacy feature.
   240 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   241 explicit paths, relatively to the theory.
   242 
   243 * Special treatment of ML file names has been discontinued.
   244 Historically, optional extensions .ML or .sml were added on demand --
   245 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   246 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   247 
   248 * Various options that affect pretty printing etc. are now properly
   249 handled within the context via configuration options, instead of
   250 unsynchronized references or print modes.  There are both ML Config.T
   251 entities and Isar declaration attributes to access these.
   252 
   253   ML (Config.T)                 Isar (attribute)
   254 
   255   eta_contract                  eta_contract
   256   show_brackets                 show_brackets
   257   show_sorts                    show_sorts
   258   show_types                    show_types
   259   show_question_marks           show_question_marks
   260   show_consts                   show_consts
   261   show_abbrevs                  show_abbrevs
   262 
   263   Syntax.ast_trace              syntax_ast_trace
   264   Syntax.ast_stat               syntax_ast_stat
   265   Syntax.ambiguity_level        syntax_ambiguity_level
   266 
   267   Goal_Display.goals_limit      goals_limit
   268   Goal_Display.show_main_goal   show_main_goal
   269 
   270   Method.rule_trace             rule_trace
   271 
   272   Thy_Output.display            thy_output_display
   273   Thy_Output.quotes             thy_output_quotes
   274   Thy_Output.indent             thy_output_indent
   275   Thy_Output.source             thy_output_source
   276   Thy_Output.break              thy_output_break
   277 
   278 Note that corresponding "..._default" references in ML may only be
   279 changed globally at the ROOT session setup, but *not* within a theory.
   280 The option "show_abbrevs" supersedes the former print mode
   281 "no_abbrevs" with inverted meaning.
   282 
   283 * More systematic naming of some configuration options.
   284 INCOMPATIBILITY.
   285 
   286   trace_simp  ~>  simp_trace
   287   debug_simp  ~>  simp_debug
   288 
   289 * Support for real valued configuration options, using simplistic
   290 floating-point notation that coincides with the inner syntax for
   291 float_token.
   292 
   293 * Support for real valued preferences (with approximative PGIP type):
   294 front-ends need to accept "pgint" values in float notation.
   295 INCOMPATIBILITY.
   296 
   297 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   298 DejaVu Sans.
   299 
   300 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   301 
   302 
   303 *** Pure ***
   304 
   305 * Command 'type_synonym' (with single argument) replaces somewhat
   306 outdated 'types', which is still available as legacy feature for some
   307 time.
   308 
   309 * Command 'nonterminal' (with 'and' separated list of arguments)
   310 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   311 
   312 * Command 'notepad' replaces former 'example_proof' for
   313 experimentation in Isar without any result.  INCOMPATIBILITY.
   314 
   315 * Locale interpretation commands 'interpret' and 'sublocale' accept
   316 lists of equations to map definitions in a locale to appropriate
   317 entities in the context of the interpretation.  The 'interpretation'
   318 command already provided this functionality.
   319 
   320 * Diagnostic command 'print_dependencies' prints the locale instances
   321 that would be activated if the specified expression was interpreted in
   322 the current context.  Variant "print_dependencies!" assumes a context
   323 without interpretations.
   324 
   325 * Diagnostic command 'print_interps' prints interpretations in proofs
   326 in addition to interpretations in theories.
   327 
   328 * Discontinued obsolete 'global' and 'local' commands to manipulate
   329 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   330 Sign.root_path and Sign.local_path may be applied directly where this
   331 feature is still required for historical reasons.
   332 
   333 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   334 'definition' instead.
   335 
   336 * The "prems" fact, which refers to the accidental collection of
   337 foundational premises in the context, is now explicitly marked as
   338 legacy feature and will be discontinued soon.  Consider using "assms"
   339 of the head statement or reference facts by explicit names.
   340 
   341 * Document antiquotations @{class} and @{type} print classes and type
   342 constructors.
   343 
   344 * Document antiquotation @{file} checks file/directory entries within
   345 the local file system.
   346 
   347 
   348 *** HOL ***
   349 
   350 * Coercive subtyping: functions can be declared as coercions and type
   351 inference will add them as necessary upon input of a term.  Theory
   352 Complex_Main declares real :: nat => real and real :: int => real as
   353 coercions. A coercion function f is declared like this:
   354 
   355   declare [[coercion f]]
   356 
   357 To lift coercions through type constructors (e.g. from nat => real to
   358 nat list => real list), map functions can be declared, e.g.
   359 
   360   declare [[coercion_map map]]
   361 
   362 Currently coercion inference is activated only in theories including
   363 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   364 the configuration option "coercion_enabled", e.g. it can be enabled in
   365 other theories like this:
   366 
   367   declare [[coercion_enabled]]
   368 
   369 * Command 'partial_function' provides basic support for recursive
   370 function definitions over complete partial orders.  Concrete instances
   371 are provided for i) the option type, ii) tail recursion on arbitrary
   372 types, and iii) the heap monad of Imperative_HOL.  See
   373 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   374 for examples.
   375 
   376 * Function package: f.psimps rules are no longer implicitly declared
   377 as [simp].  INCOMPATIBILITY.
   378 
   379 * Datatype package: theorems generated for executable equality (class
   380 "eq") carry proper names and are treated as default code equations.
   381 
   382 * Inductive package: now offers command 'inductive_simps' to
   383 automatically derive instantiated and simplified equations for
   384 inductive predicates, similar to 'inductive_cases'.
   385 
   386 * Command 'enriched_type' allows to register properties of the
   387 functorial structure of types.
   388 
   389 * Improved infrastructure for term evaluation using code generator
   390 techniques, in particular static evaluation conversions.
   391 
   392 * Code generator: Scala (2.8 or higher) has been added to the target
   393 languages.
   394 
   395 * Code generator: globbing constant expressions "*" and "Theory.*"
   396 have been replaced by the more idiomatic "_" and "Theory._".
   397 INCOMPATIBILITY.
   398 
   399 * Code generator: export_code without explicit file declaration prints
   400 to standard output.  INCOMPATIBILITY.
   401 
   402 * Code generator: do not print function definitions for case
   403 combinators any longer.
   404 
   405 * Code generator: simplification with rules determined with
   406 src/Tools/Code/code_simp.ML and method "code_simp".
   407 
   408 * Code generator for records: more idiomatic representation of record
   409 types.  Warning: records are not covered by ancient SML code
   410 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   411 rep_datatype declaration helps to succeed then:
   412 
   413   record 'a foo = ...
   414   ...
   415   rep_datatype foo_ext ...
   416 
   417 * Records: logical foundation type for records does not carry a
   418 '_type' suffix any longer (obsolete due to authentic syntax).
   419 INCOMPATIBILITY.
   420 
   421 * Quickcheck now by default uses exhaustive testing instead of random
   422 testing.  Random testing can be invoked by "quickcheck [random]",
   423 exhaustive testing by "quickcheck [exhaustive]".
   424 
   425 * Quickcheck instantiates polymorphic types with small finite
   426 datatypes by default. This enables a simple execution mechanism to
   427 handle quantifiers and function equality over the finite datatypes.
   428 
   429 * Quickcheck random generator has been renamed from "code" to
   430 "random".  INCOMPATIBILITY.
   431 
   432 * Quickcheck now has a configurable time limit which is set to 30
   433 seconds by default. This can be changed by adding [timeout = n] to the
   434 quickcheck command. The time limit for Auto Quickcheck is still set
   435 independently.
   436 
   437 * Quickcheck in locales considers interpretations of that locale for
   438 counter example search.
   439 
   440 * Sledgehammer:
   441   - Added "smt" and "remote_smt" provers based on the "smt" proof
   442     method. See the Sledgehammer manual for details ("isabelle doc
   443     sledgehammer").
   444   - Renamed commands:
   445     sledgehammer atp_info ~> sledgehammer running_provers
   446     sledgehammer atp_kill ~> sledgehammer kill_provers
   447     sledgehammer available_atps ~> sledgehammer available_provers
   448     INCOMPATIBILITY.
   449   - Renamed options:
   450     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   451     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   452     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   453     (and "ms" and "min" are no longer supported)
   454     INCOMPATIBILITY.
   455 
   456 * Nitpick:
   457   - Renamed options:
   458     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   459     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   460     INCOMPATIBILITY.
   461   - Added support for partial quotient types.
   462   - Added local versions of the "Nitpick.register_xxx" functions.
   463   - Added "whack" option.
   464   - Allow registration of quotient types as codatatypes.
   465   - Improved "merge_type_vars" option to merge more types.
   466   - Removed unsound "fast_descrs" option.
   467   - Added custom symmetry breaking for datatypes, making it possible to reach
   468     higher cardinalities.
   469   - Prevent the expansion of too large definitions.
   470 
   471 * Proof methods "metis" and "meson" now have configuration options
   472 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   473 to diagnose these tools. E.g.
   474 
   475     using [[metis_trace = true]]
   476 
   477 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   478 manually as command 'solve_direct'.
   479 
   480 * The default SMT solver Z3 must be enabled explicitly (due to
   481 licensing issues) by setting the environment variable
   482 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   483 commercial applications, the SMT solver CVC3 is provided as fall-back;
   484 changing the SMT solver is done via the configuration option
   485 "smt_solver".
   486 
   487 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   488 i.e. "remote_cvc3" and "remote_z3".
   489 
   490 * Added basic SMT support for datatypes, records, and typedefs using
   491 the oracle mode (no proofs).  Direct support of pairs has been dropped
   492 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   493 support for a similar behavior).  Minor INCOMPATIBILITY.
   494 
   495 * Changed SMT configuration options:
   496   - Renamed:
   497     z3_proofs ~> smt_oracle (with inverted meaning)
   498     z3_trace_assms ~> smt_trace_used_facts
   499     INCOMPATIBILITY.
   500   - Added:
   501     smt_verbose
   502     smt_random_seed
   503     smt_datatypes
   504     smt_infer_triggers
   505     smt_monomorph_limit
   506     cvc3_options
   507     remote_cvc3_options
   508     remote_z3_options
   509     yices_options
   510 
   511 * Boogie output files (.b2i files) need to be declared in the theory
   512 header.
   513 
   514 * Simplification procedure "list_to_set_comprehension" rewrites list
   515 comprehensions applied to List.set to set comprehensions.  Occasional
   516 INCOMPATIBILITY, may be deactivated like this:
   517 
   518   declare [[simproc del: list_to_set_comprehension]]
   519 
   520 * Removed old version of primrec package.  INCOMPATIBILITY.
   521 
   522 * Removed simplifier congruence rule of "prod_case", as has for long
   523 been the case with "split".  INCOMPATIBILITY.
   524 
   525 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   526 
   527 * Removed [split_format ... and ... and ...] version of
   528 [split_format].  Potential INCOMPATIBILITY.
   529 
   530 * Predicate "sorted" now defined inductively, with nice induction
   531 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   532 
   533 * Constant "contents" renamed to "the_elem", to free the generic name
   534 contents for other uses.  INCOMPATIBILITY.
   535 
   536 * Renamed class eq and constant eq (for code generation) to class
   537 equal and constant equal, plus renaming of related facts and various
   538 tuning.  INCOMPATIBILITY.
   539 
   540 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   541 
   542 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   543 INCOMPATIBILITY.
   544 
   545 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   546 avoid confusion with finite sets.  INCOMPATIBILITY.
   547 
   548 * Abandoned locales equiv, congruent and congruent2 for equivalence
   549 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   550 for congruent(2)).
   551 
   552 * Some previously unqualified names have been qualified:
   553 
   554   types
   555     bool ~> HOL.bool
   556     nat ~> Nat.nat
   557 
   558   constants
   559     Trueprop ~> HOL.Trueprop
   560     True ~> HOL.True
   561     False ~> HOL.False
   562     op & ~> HOL.conj
   563     op | ~> HOL.disj
   564     op --> ~> HOL.implies
   565     op = ~> HOL.eq
   566     Not ~> HOL.Not
   567     The ~> HOL.The
   568     All ~> HOL.All
   569     Ex ~> HOL.Ex
   570     Ex1 ~> HOL.Ex1
   571     Let ~> HOL.Let
   572     If ~> HOL.If
   573     Ball ~> Set.Ball
   574     Bex ~> Set.Bex
   575     Suc ~> Nat.Suc
   576     Pair ~> Product_Type.Pair
   577     fst ~> Product_Type.fst
   578     snd ~> Product_Type.snd
   579     curry ~> Product_Type.curry
   580     op : ~> Set.member
   581     Collect ~> Set.Collect
   582 
   583 INCOMPATIBILITY.
   584 
   585 * More canonical naming convention for some fundamental definitions:
   586 
   587     bot_bool_eq ~> bot_bool_def
   588     top_bool_eq ~> top_bool_def
   589     inf_bool_eq ~> inf_bool_def
   590     sup_bool_eq ~> sup_bool_def
   591     bot_fun_eq  ~> bot_fun_def
   592     top_fun_eq  ~> top_fun_def
   593     inf_fun_eq  ~> inf_fun_def
   594     sup_fun_eq  ~> sup_fun_def
   595 
   596 INCOMPATIBILITY.
   597 
   598 * More stylized fact names:
   599 
   600   expand_fun_eq ~> fun_eq_iff
   601   expand_set_eq ~> set_eq_iff
   602   set_ext       ~> set_eqI
   603   nat_number    ~> eval_nat_numeral
   604 
   605 INCOMPATIBILITY.
   606 
   607 * Refactoring of code-generation specific operations in theory List:
   608 
   609   constants
   610     null ~> List.null
   611 
   612   facts
   613     mem_iff ~> member_def
   614     null_empty ~> null_def
   615 
   616 INCOMPATIBILITY.  Note that these were not supposed to be used
   617 regularly unless for striking reasons; their main purpose was code
   618 generation.
   619 
   620 Various operations from the Haskell prelude are used for generating
   621 Haskell code.
   622 
   623 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   624 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   625 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   626 
   627 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   628 "*" and "+" respectively.  INCOMPATIBILITY.
   629 
   630 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   631 "Sum_Type.Plus" instead.
   632 
   633 * Constant "split" has been merged with constant "prod_case"; names of
   634 ML functions, facts etc. involving split have been retained so far,
   635 though.  INCOMPATIBILITY.
   636 
   637 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   638 instead.  INCOMPATIBILITY.
   639 
   640 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   641 INCOMPATIBILITY.
   642 
   643 * Former theory Library/Enum is now part of the HOL-Main image.
   644 INCOMPATIBILITY: all constants of the Enum theory now have to be
   645 referred to by its qualified name.
   646 
   647   enum    ~>  Enum.enum
   648   nlists  ~>  Enum.nlists
   649   product ~>  Enum.product
   650 
   651 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   652 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   653 INCOMPATIBILITY.
   654 
   655 * Theory Library/SetsAndFunctions has been split into
   656 Library/Function_Algebras and Library/Set_Algebras; canonical names
   657 for instance definitions for functions; various improvements.
   658 INCOMPATIBILITY.
   659 
   660 * Theory Library/Multiset provides stable quicksort implementation of
   661 sort_key.
   662 
   663 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   664 INCOMPATIBILITY.
   665 
   666 * Session Multivariate_Analysis: introduced a type class for euclidean
   667 space.  Most theorems are now stated in terms of euclidean spaces
   668 instead of finite cartesian products.
   669 
   670   types
   671     real ^ 'n ~>  'a::real_vector
   672               ~>  'a::euclidean_space
   673               ~>  'a::ordered_euclidean_space
   674         (depends on your needs)
   675 
   676   constants
   677      _ $ _        ~> _ $$ _
   678      \<chi> x. _  ~> \<chi>\<chi> x. _
   679      CARD('n)     ~> DIM('a)
   680 
   681 Also note that the indices are now natural numbers and not from some
   682 finite type. Finite cartesian products of euclidean spaces, products
   683 of euclidean spaces the real and complex numbers are instantiated to
   684 be euclidean_spaces.  INCOMPATIBILITY.
   685 
   686 * Session Probability: introduced pextreal as positive extended real
   687 numbers.  Use pextreal as value for measures.  Introduce the
   688 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   689 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   690 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   691 
   692 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   693 INCOMPATIBILITY.
   694 
   695 * Session SPARK (with image HOL-SPARK) provides commands to load and
   696 prove verification conditions generated by the SPARK Ada program
   697 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   698 
   699 
   700 *** HOL-Algebra ***
   701 
   702 * Theorems for additive ring operations (locale abelian_monoid and
   703 descendants) are generated by interpretation from their multiplicative
   704 counterparts.  Names (in particular theorem names) have the mandatory
   705 qualifier 'add'.  Previous theorem names are redeclared for
   706 compatibility.
   707 
   708 * Structure "int_ring" is now an abbreviation (previously a
   709 definition).  This fits more natural with advanced interpretations.
   710 
   711 
   712 *** HOLCF ***
   713 
   714 * The domain package now runs in definitional mode by default: The
   715 former command 'new_domain' is now called 'domain'.  To use the domain
   716 package in its original axiomatic mode, use 'domain (unsafe)'.
   717 INCOMPATIBILITY.
   718 
   719 * The new class "domain" is now the default sort.  Class "predomain"
   720 is an unpointed version of "domain". Theories can be updated by
   721 replacing sort annotations as shown below.  INCOMPATIBILITY.
   722 
   723   'a::type ~> 'a::countable
   724   'a::cpo  ~> 'a::predomain
   725   'a::pcpo ~> 'a::domain
   726 
   727 * The old type class "rep" has been superseded by class "domain".
   728 Accordingly, users of the definitional package must remove any
   729 "default_sort rep" declarations.  INCOMPATIBILITY.
   730 
   731 * The domain package (definitional mode) now supports unpointed
   732 predomain argument types, as long as they are marked 'lazy'. (Strict
   733 arguments must be in class "domain".) For example, the following
   734 domain definition now works:
   735 
   736   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   737 
   738 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   739 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   740 'a option, and 'a list.  Additionally, it configures fixrec and the
   741 domain package to work with these types.  For example:
   742 
   743   fixrec isInl :: "('a + 'b) u -> tr"
   744     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   745 
   746   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   747 
   748 * The "(permissive)" option of fixrec has been replaced with a
   749 per-equation "(unchecked)" option. See
   750 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   751 
   752 * The "bifinite" class no longer fixes a constant "approx"; the class
   753 now just asserts that such a function exists.  INCOMPATIBILITY.
   754 
   755 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   756 defines an embedding of type 'a defl into udom by default; instances
   757 of "bifinite" and "domain" classes are available in
   758 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   759 
   760 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   761 
   762 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   763 
   764 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   765 
   766 * The function "cprod_map" has been renamed to "prod_map".
   767 INCOMPATIBILITY.
   768 
   769 * The monadic bind operator on each powerdomain has new binder syntax
   770 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   771 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   772 
   773 * The infix syntax for binary union on each powerdomain has changed
   774 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   775 syntax.  INCOMPATIBILITY.
   776 
   777 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   778 still supported as an input translation.
   779 
   780 * Renamed some theorems (the original names are also still available).
   781 
   782   expand_fun_below   ~> fun_below_iff
   783   below_fun_ext      ~> fun_belowI
   784   expand_cfun_eq     ~> cfun_eq_iff
   785   ext_cfun           ~> cfun_eqI
   786   expand_cfun_below  ~> cfun_below_iff
   787   below_cfun_ext     ~> cfun_belowI
   788   cont2cont_Rep_CFun ~> cont2cont_APP
   789 
   790 * The Abs and Rep functions for various types have changed names.
   791 Related theorem names have also changed to match. INCOMPATIBILITY.
   792 
   793   Rep_CFun  ~> Rep_cfun
   794   Abs_CFun  ~> Abs_cfun
   795   Rep_Sprod ~> Rep_sprod
   796   Abs_Sprod ~> Abs_sprod
   797   Rep_Ssum  ~> Rep_ssum
   798   Abs_Ssum  ~> Abs_ssum
   799 
   800 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   801 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   802 
   803 * Various changes to bisimulation/coinduction with domain package:
   804 
   805   - Definitions of "bisim" constants no longer mention definedness.
   806   - With mutual recursion, "bisim" predicate is now curried.
   807   - With mutual recursion, each type gets a separate coind theorem.
   808   - Variable names in bisim_def and coinduct rules have changed.
   809 
   810 INCOMPATIBILITY.
   811 
   812 * Case combinators generated by the domain package for type "foo" are
   813 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   814 
   815 * Several theorems have been renamed to more accurately reflect the
   816 names of constants and types involved.  INCOMPATIBILITY.
   817 
   818   thelub_const    ~> lub_const
   819   lub_const       ~> is_lub_const
   820   thelubI         ~> lub_eqI
   821   is_lub_lub      ~> is_lubD2
   822   lubI            ~> is_lub_lub
   823   unique_lub      ~> is_lub_unique
   824   is_ub_lub       ~> is_lub_rangeD1
   825   lub_bin_chain   ~> is_lub_bin_chain
   826   lub_fun         ~> is_lub_fun
   827   thelub_fun      ~> lub_fun
   828   thelub_cfun     ~> lub_cfun
   829   thelub_Pair     ~> lub_Pair
   830   lub_cprod       ~> is_lub_prod
   831   thelub_cprod    ~> lub_prod
   832   minimal_cprod   ~> minimal_prod
   833   inst_cprod_pcpo ~> inst_prod_pcpo
   834   UU_I            ~> bottomI
   835   compact_UU      ~> compact_bottom
   836   deflation_UU    ~> deflation_bottom
   837   finite_deflation_UU ~> finite_deflation_bottom
   838 
   839 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   840 
   841   sq_ord_less_eq_trans ~> below_eq_trans
   842   sq_ord_eq_less_trans ~> eq_below_trans
   843   refl_less            ~> below_refl
   844   trans_less           ~> below_trans
   845   antisym_less         ~> below_antisym
   846   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   847   box_less             ~> box_below
   848   rev_trans_less       ~> rev_below_trans
   849   not_less2not_eq      ~> not_below2not_eq
   850   less_UU_iff          ~> below_UU_iff
   851   flat_less_iff        ~> flat_below_iff
   852   adm_less             ~> adm_below
   853   adm_not_less         ~> adm_not_below
   854   adm_compact_not_less ~> adm_compact_not_below
   855   less_fun_def         ~> below_fun_def
   856   expand_fun_less      ~> fun_below_iff
   857   less_fun_ext         ~> fun_belowI
   858   less_discr_def       ~> below_discr_def
   859   discr_less_eq        ~> discr_below_eq
   860   less_unit_def        ~> below_unit_def
   861   less_cprod_def       ~> below_prod_def
   862   prod_lessI           ~> prod_belowI
   863   Pair_less_iff        ~> Pair_below_iff
   864   fst_less_iff         ~> fst_below_iff
   865   snd_less_iff         ~> snd_below_iff
   866   expand_cfun_less     ~> cfun_below_iff
   867   less_cfun_ext        ~> cfun_belowI
   868   injection_less       ~> injection_below
   869   less_up_def          ~> below_up_def
   870   not_Iup_less         ~> not_Iup_below
   871   Iup_less             ~> Iup_below
   872   up_less              ~> up_below
   873   Def_inject_less_eq   ~> Def_below_Def
   874   Def_less_is_eq       ~> Def_below_iff
   875   spair_less_iff       ~> spair_below_iff
   876   less_sprod           ~> below_sprod
   877   spair_less           ~> spair_below
   878   sfst_less_iff        ~> sfst_below_iff
   879   ssnd_less_iff        ~> ssnd_below_iff
   880   fix_least_less       ~> fix_least_below
   881   dist_less_one        ~> dist_below_one
   882   less_ONE             ~> below_ONE
   883   ONE_less_iff         ~> ONE_below_iff
   884   less_sinlD           ~> below_sinlD
   885   less_sinrD           ~> below_sinrD
   886 
   887 
   888 *** FOL and ZF ***
   889 
   890 * All constant names are now qualified internally and use proper
   891 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   892 
   893 
   894 *** ML ***
   895 
   896 * Antiquotation @{assert} inlines a function bool -> unit that raises
   897 Fail if the argument is false.  Due to inlining the source position of
   898 failed assertions is included in the error output.
   899 
   900 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   901 text is in practice always evaluated with a stable theory checkpoint.
   902 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   903 
   904 * Antiquotation @{theory A} refers to theory A from the ancestry of
   905 the current context, not any accidental theory loader state as before.
   906 Potential INCOMPATIBILITY, subtle change in semantics.
   907 
   908 * Syntax.pretty_priority (default 0) configures the required priority
   909 of pretty-printed output and thus affects insertion of parentheses.
   910 
   911 * Syntax.default_root (default "any") configures the inner syntax
   912 category (nonterminal symbol) for parsing of terms.
   913 
   914 * Former exception Library.UnequalLengths now coincides with
   915 ListPair.UnequalLengths.
   916 
   917 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   918 main functionality is provided by structure Simplifier.
   919 
   920 * Renamed raw "explode" function to "raw_explode" to emphasize its
   921 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   922 almost all situations.
   923 
   924 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   925 See implementation manual for further details on exceptions in
   926 Isabelle/ML.
   927 
   928 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   929 meaning.
   930 
   931 * Renamed structure PureThy to Pure_Thy and moved most of its
   932 operations to structure Global_Theory, to emphasize that this is
   933 rarely-used global-only stuff.
   934 
   935 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   936 instead (or tracing for high-volume output).
   937 
   938 * Configuration option show_question_marks only affects regular pretty
   939 printing of types and terms, not raw Term.string_of_vname.
   940 
   941 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   942 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   943 @{thms} for most purposes.
   944 
   945 * ML structure Unsynchronized is never opened, not even in Isar
   946 interaction mode as before.  Old Unsynchronized.set etc. have been
   947 discontinued -- use plain := instead.  This should be *rare* anyway,
   948 since modern tools always work via official context data, notably
   949 configuration options.
   950 
   951 * Parallel and asynchronous execution requires special care concerning
   952 interrupts.  Structure Exn provides some convenience functions that
   953 avoid working directly with raw Interrupt.  User code must not absorb
   954 interrupts -- intermediate handling (for cleanup etc.) needs to be
   955 followed by re-raising of the original exception.  Another common
   956 source of mistakes are "handle _" patterns, which make the meaning of
   957 the program subject to physical effects of the environment.
   958 
   959 
   960 
   961 New in Isabelle2009-2 (June 2010)
   962 ---------------------------------
   963 
   964 *** General ***
   965 
   966 * Authentic syntax for *all* logical entities (type classes, type
   967 constructors, term constants): provides simple and robust
   968 correspondence between formal entities and concrete syntax.  Within
   969 the parse tree / AST representations, "constants" are decorated by
   970 their category (class, type, const) and spelled out explicitly with
   971 their full internal name.
   972 
   973 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   974 and translations (translation rules and translation functions in ML).
   975 Some hints on upgrading:
   976 
   977   - Many existing uses of 'syntax' and 'translations' can be replaced
   978     by more modern 'type_notation', 'notation' and 'abbreviation',
   979     which are independent of this issue.
   980 
   981   - 'translations' require markup within the AST; the term syntax
   982     provides the following special forms:
   983 
   984       CONST c   -- produces syntax version of constant c from context
   985       XCONST c  -- literally c, checked as constant from context
   986       c         -- literally c, if declared by 'syntax'
   987 
   988     Plain identifiers are treated as AST variables -- occasionally the
   989     system indicates accidental variables via the error "rhs contains
   990     extra variables".
   991 
   992     Type classes and type constructors are marked according to their
   993     concrete syntax.  Some old translations rules need to be written
   994     for the "type" category, using type constructor application
   995     instead of pseudo-term application of the default category
   996     "logic".
   997 
   998   - 'parse_translation' etc. in ML may use the following
   999     antiquotations:
  1000 
  1001       @{class_syntax c}   -- type class c within parse tree / AST
  1002       @{term_syntax c}    -- type constructor c within parse tree / AST
  1003       @{const_syntax c}   -- ML version of "CONST c" above
  1004       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1005 
  1006   - Literal types within 'typed_print_translations', i.e. those *not*
  1007     represented as pseudo-terms are represented verbatim.  Use @{class
  1008     c} or @{type_name c} here instead of the above syntax
  1009     antiquotations.
  1010 
  1011 Note that old non-authentic syntax was based on unqualified base
  1012 names, so all of the above "constant" names would coincide.  Recall
  1013 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1014 diagnose syntax problems.
  1015 
  1016 * Type constructors admit general mixfix syntax, not just infix.
  1017 
  1018 * Concrete syntax may be attached to local entities without a proof
  1019 body, too.  This works via regular mixfix annotations for 'fix',
  1020 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1021 similar to the 'notation' command in theory specifications.
  1022 
  1023 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1024 need to specify constant name and syntax separately.  Internal ML
  1025 datatype constructors have been renamed from InfixName to Infix etc.
  1026 Minor INCOMPATIBILITY.
  1027 
  1028 * Schematic theorem statements need to be explicitly markup as such,
  1029 via commands 'schematic_lemma', 'schematic_theorem',
  1030 'schematic_corollary'.  Thus the relevance of the proof is made
  1031 syntactically clear, which impacts performance in a parallel or
  1032 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1033 
  1034 * Use of cumulative prems via "!" in some proof methods has been
  1035 discontinued (old legacy feature).
  1036 
  1037 * References 'trace_simp' and 'debug_simp' have been replaced by
  1038 configuration options stored in the context. Enabling tracing (the
  1039 case of debugging is similar) in proofs works via
  1040 
  1041   using [[trace_simp = true]]
  1042 
  1043 Tracing is then active for all invocations of the simplifier in
  1044 subsequent goal refinement steps. Tracing may also still be enabled or
  1045 disabled via the ProofGeneral settings menu.
  1046 
  1047 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1048 'hide_fact' replace the former 'hide' KIND command.  Minor
  1049 INCOMPATIBILITY.
  1050 
  1051 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1052 more efficient than combinations with -q1 or -q2.
  1053 
  1054 
  1055 *** Pure ***
  1056 
  1057 * Proofterms record type-class reasoning explicitly, using the
  1058 "unconstrain" operation internally.  This eliminates all sort
  1059 constraints from a theorem and proof, introducing explicit
  1060 OFCLASS-premises.  On the proof term level, this operation is
  1061 automatically applied at theorem boundaries, such that closed proofs
  1062 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1063 inspect proof terms.
  1064 
  1065 * Local theory specifications may depend on extra type variables that
  1066 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1067 are added internally.  For example:
  1068 
  1069   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1070 
  1071 * Predicates of locales introduced by classes carry a mandatory
  1072 "class" prefix.  INCOMPATIBILITY.
  1073 
  1074 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1075 
  1076 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1077 'class' instead.
  1078 
  1079 * Command 'code_reflect' allows to incorporate generated ML code into
  1080 runtime environment; replaces immature code_datatype antiquotation.
  1081 INCOMPATIBILITY.
  1082 
  1083 * Code generator: simple concept for abstract datatypes obeying
  1084 invariants.
  1085 
  1086 * Code generator: details of internal data cache have no impact on the
  1087 user space functionality any longer.
  1088 
  1089 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1090 subgoals.  This is more appropriate for interpretations with 'where'.
  1091 INCOMPATIBILITY.
  1092 
  1093 * Command 'example_proof' opens an empty proof body.  This allows to
  1094 experiment with Isar, without producing any persistent result.
  1095 
  1096 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1097 within a local theory context, with explicit checking of the
  1098 constructors involved (in contrast to the raw 'syntax' versions).
  1099 
  1100 * Commands 'types' and 'typedecl' now work within a local theory
  1101 context -- without introducing dependencies on parameters or
  1102 assumptions, which is not possible in Isabelle/Pure.
  1103 
  1104 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1105 within a local theory context.  Minor INCOMPATIBILITY.
  1106 
  1107 
  1108 *** HOL ***
  1109 
  1110 * Command 'typedef' now works within a local theory context -- without
  1111 introducing dependencies on parameters or assumptions, which is not
  1112 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1113 contain multiple interpretations of local typedefs (with different
  1114 non-emptiness proofs), even in a global theory context.
  1115 
  1116 * New package for quotient types.  Commands 'quotient_type' and
  1117 'quotient_definition' may be used for defining types and constants by
  1118 quotient constructions.  An example is the type of integers created by
  1119 quotienting pairs of natural numbers:
  1120 
  1121   fun
  1122     intrel :: "(nat * nat) => (nat * nat) => bool"
  1123   where
  1124     "intrel (x, y) (u, v) = (x + v = u + y)"
  1125 
  1126   quotient_type int = "nat * nat" / intrel
  1127     by (auto simp add: equivp_def expand_fun_eq)
  1128 
  1129   quotient_definition
  1130     "0::int" is "(0::nat, 0::nat)"
  1131 
  1132 The method "lifting" can be used to lift of theorems from the
  1133 underlying "raw" type to the quotient type.  The example
  1134 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1135 construction and provides a reasoning infrastructure for finite sets.
  1136 
  1137 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1138 clash with new theory Quotient in Main HOL.
  1139 
  1140 * Moved the SMT binding into the main HOL session, eliminating
  1141 separate HOL-SMT session.
  1142 
  1143 * List membership infix mem operation is only an input abbreviation.
  1144 INCOMPATIBILITY.
  1145 
  1146 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1147 for future developements; former Library/Word.thy is still present in
  1148 the AFP entry RSAPPS.
  1149 
  1150 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1151 longer shadowed.  INCOMPATIBILITY.
  1152 
  1153 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1154 INCOMPATIBILITY.
  1155 
  1156 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1157 INCOMPATIBILITY.
  1158 
  1159 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1160 instead.  INCOMPATIBILITY.
  1161 
  1162 * Dropped several real-specific versions of lemmas about floor and
  1163 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1164 instead.  INCOMPATIBILITY.
  1165 
  1166   floor_number_of_eq         ~> floor_number_of
  1167   le_floor_eq_number_of      ~> number_of_le_floor
  1168   le_floor_eq_zero           ~> zero_le_floor
  1169   le_floor_eq_one            ~> one_le_floor
  1170   floor_less_eq_number_of    ~> floor_less_number_of
  1171   floor_less_eq_zero         ~> floor_less_zero
  1172   floor_less_eq_one          ~> floor_less_one
  1173   less_floor_eq_number_of    ~> number_of_less_floor
  1174   less_floor_eq_zero         ~> zero_less_floor
  1175   less_floor_eq_one          ~> one_less_floor
  1176   floor_le_eq_number_of      ~> floor_le_number_of
  1177   floor_le_eq_zero           ~> floor_le_zero
  1178   floor_le_eq_one            ~> floor_le_one
  1179   floor_subtract_number_of   ~> floor_diff_number_of
  1180   floor_subtract_one         ~> floor_diff_one
  1181   ceiling_number_of_eq       ~> ceiling_number_of
  1182   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1183   ceiling_le_zero_eq         ~> ceiling_le_zero
  1184   ceiling_le_eq_one          ~> ceiling_le_one
  1185   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1186   less_ceiling_eq_zero       ~> zero_less_ceiling
  1187   less_ceiling_eq_one        ~> one_less_ceiling
  1188   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1189   ceiling_less_eq_zero       ~> ceiling_less_zero
  1190   ceiling_less_eq_one        ~> ceiling_less_one
  1191   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1192   le_ceiling_eq_zero         ~> zero_le_ceiling
  1193   le_ceiling_eq_one          ~> one_le_ceiling
  1194   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1195   ceiling_subtract_one       ~> ceiling_diff_one
  1196 
  1197 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1198 application of the various fold combinators on finite sets.
  1199 
  1200 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1201 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1202 implementation.  INCOMPATIBILTY.
  1203 
  1204 * Theory Library/Coinductive_List has been removed -- superseded by
  1205 AFP/thys/Coinductive.
  1206 
  1207 * Theory PReal, including the type "preal" and related operations, has
  1208 been removed.  INCOMPATIBILITY.
  1209 
  1210 * Real: new development using Cauchy Sequences.
  1211 
  1212 * Split off theory "Big_Operators" containing setsum, setprod,
  1213 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1214 
  1215 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1216 "Int" etc.  INCOMPATIBILITY.
  1217 
  1218 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1219 
  1220 * New set of rules "ac_simps" provides combined assoc / commute
  1221 rewrites for all interpretations of the appropriate generic locales.
  1222 
  1223 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1224 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1225 appropriate and more consistent names suitable for name prefixes
  1226 within the HOL theories.  INCOMPATIBILITY.
  1227 
  1228 * Some generic constants have been put to appropriate theories:
  1229   - less_eq, less: Orderings
  1230   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1231   - inverse, divide: Rings
  1232 INCOMPATIBILITY.
  1233 
  1234 * More consistent naming of type classes involving orderings (and
  1235 lattices):
  1236 
  1237     lower_semilattice                   ~> semilattice_inf
  1238     upper_semilattice                   ~> semilattice_sup
  1239 
  1240     dense_linear_order                  ~> dense_linorder
  1241 
  1242     pordered_ab_group_add               ~> ordered_ab_group_add
  1243     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1244     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1245     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1246     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1247     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1248     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1249     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1250     pordered_comm_ring                  ~> ordered_comm_ring
  1251     pordered_comm_semiring              ~> ordered_comm_semiring
  1252     pordered_ring                       ~> ordered_ring
  1253     pordered_ring_abs                   ~> ordered_ring_abs
  1254     pordered_semiring                   ~> ordered_semiring
  1255 
  1256     ordered_ab_group_add                ~> linordered_ab_group_add
  1257     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1258     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1259     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1260     ordered_field                       ~> linordered_field
  1261     ordered_field_no_lb                 ~> linordered_field_no_lb
  1262     ordered_field_no_ub                 ~> linordered_field_no_ub
  1263     ordered_field_dense_linear_order    ~> dense_linordered_field
  1264     ordered_idom                        ~> linordered_idom
  1265     ordered_ring                        ~> linordered_ring
  1266     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1267     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1268     ordered_ring_strict                 ~> linordered_ring_strict
  1269     ordered_semidom                     ~> linordered_semidom
  1270     ordered_semiring                    ~> linordered_semiring
  1271     ordered_semiring_1                  ~> linordered_semiring_1
  1272     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1273     ordered_semiring_strict             ~> linordered_semiring_strict
  1274 
  1275   The following slightly odd type classes have been moved to a
  1276   separate theory Library/Lattice_Algebras:
  1277 
  1278     lordered_ab_group_add               ~> lattice_ab_group_add
  1279     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1280     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1281     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1282     lordered_ring                       ~> lattice_ring
  1283 
  1284 INCOMPATIBILITY.
  1285 
  1286 * Refined field classes:
  1287   - classes division_ring_inverse_zero, field_inverse_zero,
  1288     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1289     subsumes former division_by_zero class;
  1290   - numerous lemmas have been ported from field to division_ring.
  1291 INCOMPATIBILITY.
  1292 
  1293 * Refined algebra theorem collections:
  1294   - dropped theorem group group_simps, use algebra_simps instead;
  1295   - dropped theorem group ring_simps, use field_simps instead;
  1296   - proper theorem collection field_simps subsumes former theorem
  1297     groups field_eq_simps and field_simps;
  1298   - dropped lemma eq_minus_self_iff which is a duplicate for
  1299     equal_neg_zero.
  1300 INCOMPATIBILITY.
  1301 
  1302 * Theory Finite_Set and List: some lemmas have been generalized from
  1303 sets to lattices:
  1304 
  1305   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1306   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1307   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1308   union_Union_fold_union        ~> sup_Sup_fold_sup
  1309   Inter_fold_inter              ~> Inf_fold_inf
  1310   Union_fold_union              ~> Sup_fold_sup
  1311   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1312   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1313   INTER_fold_inter              ~> INFI_fold_inf
  1314   UNION_fold_union              ~> SUPR_fold_sup
  1315 
  1316 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1317 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1318 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1319 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1320 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1321 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1322 
  1323 * Reorganized theory Multiset: swapped notation of pointwise and
  1324 multiset order:
  1325 
  1326   - pointwise ordering is instance of class order with standard syntax
  1327     <= and <;
  1328   - multiset ordering has syntax <=# and <#; partial order properties
  1329     are provided by means of interpretation with prefix
  1330     multiset_order;
  1331   - less duplication, less historical organization of sections,
  1332     conversion from associations lists to multisets, rudimentary code
  1333     generation;
  1334   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1335     if needed.
  1336 
  1337 Renamed:
  1338 
  1339   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1340   multi_count_ext  ~>  multiset_ext
  1341   diff_union_inverse2  ~>  diff_union_cancelR
  1342 
  1343 INCOMPATIBILITY.
  1344 
  1345 * Theory Permutation: replaced local "remove" by List.remove1.
  1346 
  1347 * Code generation: ML and OCaml code is decorated with signatures.
  1348 
  1349 * Theory List: added transpose.
  1350 
  1351 * Library/Nat_Bijection.thy is a collection of bijective functions
  1352 between nat and other types, which supersedes the older libraries
  1353 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1354 
  1355   Constants:
  1356   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1357   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1358   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1359   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1360   Countable.pair_encode           ~> prod_encode
  1361   NatIso.prod2nat                 ~> prod_encode
  1362   NatIso.nat2prod                 ~> prod_decode
  1363   NatIso.sum2nat                  ~> sum_encode
  1364   NatIso.nat2sum                  ~> sum_decode
  1365   NatIso.list2nat                 ~> list_encode
  1366   NatIso.nat2list                 ~> list_decode
  1367   NatIso.set2nat                  ~> set_encode
  1368   NatIso.nat2set                  ~> set_decode
  1369 
  1370   Lemmas:
  1371   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1372   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1373   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1374   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1375   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1376   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1377   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1378   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1379   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1380   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1381   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1382   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1383   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1384 
  1385 * Sledgehammer:
  1386   - Renamed ATP commands:
  1387     atp_info     ~> sledgehammer running_atps
  1388     atp_kill     ~> sledgehammer kill_atps
  1389     atp_messages ~> sledgehammer messages
  1390     atp_minimize ~> sledgehammer minimize
  1391     print_atps   ~> sledgehammer available_atps
  1392     INCOMPATIBILITY.
  1393   - Added user's manual ("isabelle doc sledgehammer").
  1394   - Added option syntax and "sledgehammer_params" to customize
  1395     Sledgehammer's behavior.  See the manual for details.
  1396   - Modified the Isar proof reconstruction code so that it produces
  1397     direct proofs rather than proofs by contradiction.  (This feature
  1398     is still experimental.)
  1399   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1400     full-typed mode.
  1401   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1402 
  1403 * Nitpick:
  1404   - Added and implemented "binary_ints" and "bits" options.
  1405   - Added "std" option and implemented support for nonstandard models.
  1406   - Added and implemented "finitize" option to improve the precision
  1407     of infinite datatypes based on a monotonicity analysis.
  1408   - Added support for quotient types.
  1409   - Added support for "specification" and "ax_specification"
  1410     constructs.
  1411   - Added support for local definitions (for "function" and
  1412     "termination" proofs).
  1413   - Added support for term postprocessors.
  1414   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1415   - Improved efficiency of "destroy_constrs" optimization.
  1416   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1417     record getters.
  1418   - Fixed soundness bug related to higher-order constructors.
  1419   - Fixed soundness bug when "full_descrs" is enabled.
  1420   - Improved precision of set constructs.
  1421   - Added "atoms" option.
  1422   - Added cache to speed up repeated Kodkod invocations on the same
  1423     problems.
  1424   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1425     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1426     "SAT4J_Light".  INCOMPATIBILITY.
  1427   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1428     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1429   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1430 
  1431 * Method "induct" now takes instantiations of the form t, where t is not
  1432   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1433   If this is not intended, t has to be enclosed in parentheses.
  1434   By default, the equalities generated by definitional instantiations
  1435   are pre-simplified, which may cause parameters of inductive cases
  1436   to disappear, or may even delete some of the inductive cases.
  1437   Use "induct (no_simp)" instead of "induct" to restore the old
  1438   behaviour. The (no_simp) option is also understood by the "cases"
  1439   and "nominal_induct" methods, which now perform pre-simplification, too.
  1440   INCOMPATIBILITY.
  1441 
  1442 
  1443 *** HOLCF ***
  1444 
  1445 * Variable names in lemmas generated by the domain package have
  1446 changed; the naming scheme is now consistent with the HOL datatype
  1447 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1448 
  1449 * The domain package no longer defines the function "foo_copy" for
  1450 recursive domain "foo".  The reach lemma is now stated directly in
  1451 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1452 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1453 
  1454 * Most definedness lemmas generated by the domain package (previously
  1455 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1456 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1457 Proofs that used definedness lemmas as intro rules may break,
  1458 potential INCOMPATIBILITY.
  1459 
  1460 * Induction and casedist rules generated by the domain package now
  1461 declare proper case_names (one called "bottom", and one named for each
  1462 constructor).  INCOMPATIBILITY.
  1463 
  1464 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1465 rules are generated for each domain, INCOMPATIBILITY.
  1466 
  1467   foo_bar.reach       ~> foo.reach  bar.reach
  1468   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1469 
  1470 * Some lemmas generated by the domain package have been renamed for
  1471 consistency with the datatype package, INCOMPATIBILITY.
  1472 
  1473   foo.ind        ~> foo.induct
  1474   foo.finite_ind ~> foo.finite_induct
  1475   foo.coind      ~> foo.coinduct
  1476   foo.casedist   ~> foo.exhaust
  1477   foo.exhaust    ~> foo.nchotomy
  1478 
  1479 * For consistency with other definition packages, the fixrec package
  1480 now generates qualified theorem names, INCOMPATIBILITY.
  1481 
  1482   foo_simps  ~> foo.simps
  1483   foo_unfold ~> foo.unfold
  1484   foo_induct ~> foo.induct
  1485 
  1486 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1487 method and internal fixrec proofs now use the default simpset instead.
  1488 INCOMPATIBILITY.
  1489 
  1490 * The "contlub" predicate has been removed.  Proof scripts should use
  1491 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1492 
  1493 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1494 
  1495 * The constants cpair, cfst, and csnd have been removed in favor of
  1496 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1497 
  1498 
  1499 *** ML ***
  1500 
  1501 * Antiquotations for basic formal entities:
  1502 
  1503     @{class NAME}         -- type class
  1504     @{class_syntax NAME}  -- syntax representation of the above
  1505 
  1506     @{type_name NAME}     -- logical type
  1507     @{type_abbrev NAME}   -- type abbreviation
  1508     @{nonterminal NAME}   -- type of concrete syntactic category
  1509     @{type_syntax NAME}   -- syntax representation of any of the above
  1510 
  1511     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1512     @{const_abbrev NAME}  -- abbreviated constant
  1513     @{const_syntax NAME}  -- syntax representation of any of the above
  1514 
  1515 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1516 syntax constant (cf. 'syntax' command).
  1517 
  1518 * Antiquotation @{make_string} inlines a function to print arbitrary
  1519 values similar to the ML toplevel.  The result is compiler dependent
  1520 and may fall back on "?" in certain situations.
  1521 
  1522 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1523 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1524 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1525 not work with the asynchronous Isar document model.
  1526 
  1527 * Configuration options now admit dynamic default values, depending on
  1528 the context or even global references.
  1529 
  1530 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1531 uses an efficient external library if available (for Poly/ML).
  1532 
  1533 * Renamed some important ML structures, while keeping the old names
  1534 for some time as aliases within the structure Legacy:
  1535 
  1536   OuterKeyword  ~>  Keyword
  1537   OuterLex      ~>  Token
  1538   OuterParse    ~>  Parse
  1539   OuterSyntax   ~>  Outer_Syntax
  1540   PrintMode     ~>  Print_Mode
  1541   SpecParse     ~>  Parse_Spec
  1542   ThyInfo       ~>  Thy_Info
  1543   ThyLoad       ~>  Thy_Load
  1544   ThyOutput     ~>  Thy_Output
  1545   TypeInfer     ~>  Type_Infer
  1546 
  1547 Note that "open Legacy" simplifies porting of sources, but forgetting
  1548 to remove it again will complicate porting again in the future.
  1549 
  1550 * Most operations that refer to a global context are named
  1551 accordingly, e.g. Simplifier.global_context or
  1552 ProofContext.init_global.  There are some situations where a global
  1553 context actually works, but under normal circumstances one needs to
  1554 pass the proper local context through the code!
  1555 
  1556 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1557 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1558 Pretty.pp argument to merge, which is absent in the standard
  1559 Theory_Data version.
  1560 
  1561 * Sorts.certify_sort and derived "cert" operations for types and terms
  1562 no longer minimize sorts.  Thus certification at the boundary of the
  1563 inference kernel becomes invariant under addition of class relations,
  1564 which is an important monotonicity principle.  Sorts are now minimized
  1565 in the syntax layer only, at the boundary between the end-user and the
  1566 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1567 explicitly in rare situations.
  1568 
  1569 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1570 emphasize that this is in no way a standard operation.
  1571 INCOMPATIBILITY.
  1572 
  1573 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1574 usual for resolution.  Rare INCOMPATIBILITY.
  1575 
  1576 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1577 to emphasize that these only work in a global situation (which is
  1578 quite rare).
  1579 
  1580 * Curried take and drop in library.ML; negative length is interpreted
  1581 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1582 
  1583 * Proof terms: type substitutions on proof constants now use canonical
  1584 order of type variables.  INCOMPATIBILITY for tools working with proof
  1585 terms.
  1586 
  1587 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1588 may no longer carry premises.  User-level specifications are
  1589 transformed accordingly by Thm.add_axiom/add_def.
  1590 
  1591 
  1592 *** System ***
  1593 
  1594 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1595 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1596 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1597 
  1598 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1599 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1600 respectively.
  1601 
  1602 * Old lib/scripts/polyml-platform is superseded by the
  1603 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1604 variant, even on a 64 bit machine.  The following example setting
  1605 prefers 64 bit if available:
  1606 
  1607   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1608 
  1609 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1610 Isabelle/Scala layer for advanced prover interaction and integration.
  1611 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1612 component.
  1613 
  1614 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1615 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1616 similar to the default assignment of the document preparation system
  1617 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1618 provides some operations for direct access to the font without asking
  1619 the user for manual installation.
  1620 
  1621 
  1622 
  1623 New in Isabelle2009-1 (December 2009)
  1624 -------------------------------------
  1625 
  1626 *** General ***
  1627 
  1628 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1629 one backslash should be used, even in ML sources.
  1630 
  1631 
  1632 *** Pure ***
  1633 
  1634 * Locale interpretation propagates mixins along the locale hierarchy.
  1635 The currently only available mixins are the equations used to map
  1636 local definitions to terms of the target domain of an interpretation.
  1637 
  1638 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1639 loc" to print all interpretations of locale "loc" in the theory.
  1640 Interpretations in proofs are not shown.
  1641 
  1642 * Thoroughly revised locales tutorial.  New section on conditional
  1643 interpretation.
  1644 
  1645 * On instantiation of classes, remaining undefined class parameters
  1646 are formally declared.  INCOMPATIBILITY.
  1647 
  1648 
  1649 *** Document preparation ***
  1650 
  1651 * New generalized style concept for printing terms: @{foo (style) ...}
  1652 instead of @{foo_style style ...}  (old form is still retained for
  1653 backward compatibility).  Styles can be also applied for
  1654 antiquotations prop, term_type and typeof.
  1655 
  1656 
  1657 *** HOL ***
  1658 
  1659 * New proof method "smt" for a combination of first-order logic with
  1660 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1661 fixed-size bitvectors; there is also basic support for higher-order
  1662 features (esp. lambda abstractions).  It is an incomplete decision
  1663 procedure based on external SMT solvers using the oracle mechanism;
  1664 for the SMT solver Z3, this method is proof-producing.  Certificates
  1665 are provided to avoid calling the external solvers solely for
  1666 re-checking proofs.  Due to a remote SMT service there is no need for
  1667 installing SMT solvers locally.  See src/HOL/SMT.
  1668 
  1669 * New commands to load and prove verification conditions generated by
  1670 the Boogie program verifier or derived systems (e.g. the Verifying C
  1671 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1672 
  1673 * New counterexample generator tool 'nitpick' based on the Kodkod
  1674 relational model finder.  See src/HOL/Tools/Nitpick and
  1675 src/HOL/Nitpick_Examples.
  1676 
  1677 * New commands 'code_pred' and 'values' to invoke the predicate
  1678 compiler and to enumerate values of inductive predicates.
  1679 
  1680 * A tabled implementation of the reflexive transitive closure.
  1681 
  1682 * New implementation of quickcheck uses generic code generator;
  1683 default generators are provided for all suitable HOL types, records
  1684 and datatypes.  Old quickcheck can be re-activated importing theory
  1685 Library/SML_Quickcheck.
  1686 
  1687 * New testing tool Mirabelle for automated proof tools.  Applies
  1688 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1689 every proof step in a theory.  To be used in batch mode via the
  1690 "mirabelle" utility.
  1691 
  1692 * New proof method "sos" (sum of squares) for nonlinear real
  1693 arithmetic (originally due to John Harison). It requires theory
  1694 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1695 works well in practice on quantifier-free real arithmetic with +, -,
  1696 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1697 inequalities between polynomials.  It makes use of external
  1698 semidefinite programming solvers.  Method "sos" generates a
  1699 certificate that can be pasted into the proof thus avoiding the need
  1700 to call an external tool every time the proof is checked.  See
  1701 src/HOL/Library/Sum_Of_Squares.
  1702 
  1703 * New method "linarith" invokes existing linear arithmetic decision
  1704 procedure only.
  1705 
  1706 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1707 
  1708 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1709 Causes full type information to be output to the ATPs.  This slows
  1710 ATPs down considerably but eliminates a source of unsound "proofs"
  1711 that fail later.
  1712 
  1713 * New method "metisFT": A version of metis that uses full type
  1714 information in order to avoid failures of proof reconstruction.
  1715 
  1716 * New evaluator "approximate" approximates an real valued term using
  1717 the same method as the approximation method.
  1718 
  1719 * Method "approximate" now supports arithmetic expressions as
  1720 boundaries of intervals and implements interval splitting and Taylor
  1721 series expansion.
  1722 
  1723 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1724 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1725 
  1726 * New theory SupInf of the supremum and infimum operators for sets of
  1727 reals.
  1728 
  1729 * New theory Probability, which contains a development of measure
  1730 theory, eventually leading to Lebesgue integration and probability.
  1731 
  1732 * Extended Multivariate Analysis to include derivation and Brouwer's
  1733 fixpoint theorem.
  1734 
  1735 * Reorganization of number theory, INCOMPATIBILITY:
  1736   - new number theory development for nat and int, in theories Divides
  1737     and GCD as well as in new session Number_Theory
  1738   - some constants and facts now suffixed with _nat and _int
  1739     accordingly
  1740   - former session NumberTheory now named Old_Number_Theory, including
  1741     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1742   - moved theory Pocklington from src/HOL/Library to
  1743     src/HOL/Old_Number_Theory
  1744 
  1745 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1746 lcm of finite and infinite sets. It is shown that they form a complete
  1747 lattice.
  1748 
  1749 * Class semiring_div requires superclass no_zero_divisors and proof of
  1750 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1751 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1752 generalized to class semiring_div, subsuming former theorems
  1753 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1754 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1755 INCOMPATIBILITY.
  1756 
  1757 * Refinements to lattice classes and sets:
  1758   - less default intro/elim rules in locale variant, more default
  1759     intro/elim rules in class variant: more uniformity
  1760   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1761     le_inf_iff
  1762   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1763     sup_aci)
  1764   - renamed ACI to inf_sup_aci
  1765   - new class "boolean_algebra"
  1766   - class "complete_lattice" moved to separate theory
  1767     "Complete_Lattice"; corresponding constants (and abbreviations)
  1768     renamed and with authentic syntax:
  1769     Set.Inf ~>    Complete_Lattice.Inf
  1770     Set.Sup ~>    Complete_Lattice.Sup
  1771     Set.INFI ~>   Complete_Lattice.INFI
  1772     Set.SUPR ~>   Complete_Lattice.SUPR
  1773     Set.Inter ~>  Complete_Lattice.Inter
  1774     Set.Union ~>  Complete_Lattice.Union
  1775     Set.INTER ~>  Complete_Lattice.INTER
  1776     Set.UNION ~>  Complete_Lattice.UNION
  1777   - authentic syntax for
  1778     Set.Pow
  1779     Set.image
  1780   - mere abbreviations:
  1781     Set.empty               (for bot)
  1782     Set.UNIV                (for top)
  1783     Set.inter               (for inf, formerly Set.Int)
  1784     Set.union               (for sup, formerly Set.Un)
  1785     Complete_Lattice.Inter  (for Inf)
  1786     Complete_Lattice.Union  (for Sup)
  1787     Complete_Lattice.INTER  (for INFI)
  1788     Complete_Lattice.UNION  (for SUPR)
  1789   - object-logic definitions as far as appropriate
  1790 
  1791 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1792 Un_subset_iff are explicitly deleted as default simp rules; then also
  1793 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1794 deleted to achieve the desired effect.
  1795 
  1796 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1797 rules by default any longer; the same applies to min_max.inf_absorb1
  1798 etc.  INCOMPATIBILITY.
  1799 
  1800 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1801 pred_set_conv by default.  INCOMPATIBILITY.
  1802 
  1803 * Power operations on relations and functions are now one dedicated
  1804 constant "compow" with infix syntax "^^".  Power operation on
  1805 multiplicative monoids retains syntax "^" and is now defined generic
  1806 in class power.  INCOMPATIBILITY.
  1807 
  1808 * Relation composition "R O S" now has a more standard argument order:
  1809 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1810 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1811 break, since the O_assoc rule was not rewritten like this.  Fix using
  1812 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1813 
  1814 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1815 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1816 INCOMPATIBILITY.
  1817 
  1818 * Most rules produced by inductive and datatype package have mandatory
  1819 prefixes.  INCOMPATIBILITY.
  1820 
  1821 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1822 the attribute of the same name.  Each of the theorems in the list
  1823 DERIV_intros assumes composition with an additional function and
  1824 matches a variable to the derivative, which has to be solved by the
  1825 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1826 of most elementary terms.  Former Maclauren.DERIV_tac and
  1827 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1828 INCOMPATIBILITY.
  1829 
  1830 * Code generator attributes follow the usual underscore convention:
  1831     code_unfold     replaces    code unfold
  1832     code_post       replaces    code post
  1833     etc.
  1834   INCOMPATIBILITY.
  1835 
  1836 * Renamed methods:
  1837     sizechange -> size_change
  1838     induct_scheme -> induction_schema
  1839   INCOMPATIBILITY.
  1840 
  1841 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1842 INCOMPATIBILITY, use "undefined" directly.
  1843 
  1844 * Renamed theorems:
  1845     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1846     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1847     Suc_plus1 -> Suc_eq_plus1
  1848     *anti_sym -> *antisym*
  1849     vector_less_eq_def -> vector_le_def
  1850   INCOMPATIBILITY.
  1851 
  1852 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1853 INCOMPATIBILITY.
  1854 
  1855 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1856 INCOMPATIBILITY.
  1857 
  1858 
  1859 *** HOLCF ***
  1860 
  1861 * Theory Representable defines a class "rep" of domains that are
  1862 representable (via an ep-pair) in the universal domain type "udom".
  1863 Instances are provided for all type constructors defined in HOLCF.
  1864 
  1865 * The 'new_domain' command is a purely definitional version of the
  1866 domain package, for representable domains.  Syntax is identical to the
  1867 old domain package.  The 'new_domain' package also supports indirect
  1868 recursion using previously-defined type constructors.  See
  1869 src/HOLCF/ex/New_Domain.thy for examples.
  1870 
  1871 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1872 on the left-hand side of an equation, and then performs
  1873 simplification.  Rewriting is done using rules declared with the
  1874 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1875 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1876 
  1877 * The pattern-match compiler in 'fixrec' can now handle constructors
  1878 with HOL function types.  Pattern-match combinators for the Pair
  1879 constructor are pre-configured.
  1880 
  1881 * The 'fixrec' package now produces better fixed-point induction rules
  1882 for mutually-recursive definitions:  Induction rules have conclusions
  1883 of the form "P foo bar" instead of "P <foo, bar>".
  1884 
  1885 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1886 been renamed to "below".  The name "below" now replaces "less" in many
  1887 theorem names.  (Legacy theorem names using "less" are still supported
  1888 as well.)
  1889 
  1890 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1891 patterns can be used to generate strictness rules, or to make
  1892 functions more strict (much like the bang-patterns supported by the
  1893 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1894 examples.
  1895 
  1896 
  1897 *** ML ***
  1898 
  1899 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1900 errors and run-time exceptions, including detailed source positions.
  1901 
  1902 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1903 identified entries, with some additional information such as source
  1904 position, logical grouping etc.
  1905 
  1906 * Theory and context data is now introduced by the simplified and
  1907 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1908 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1909 copy operation) is still available for some time.
  1910 
  1911 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1912 provides a high-level programming interface to synchronized state
  1913 variables with atomic update.  This works via pure function
  1914 application within a critical section -- its runtime should be as
  1915 short as possible; beware of deadlocks if critical code is nested,
  1916 either directly or indirectly via other synchronized variables!
  1917 
  1918 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1919 wraps raw ML references, explicitly indicating their non-thread-safe
  1920 behaviour.  The Isar toplevel keeps this structure open, to
  1921 accommodate Proof General as well as quick and dirty interactive
  1922 experiments with references.
  1923 
  1924 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1925 parallel tactical reasoning.
  1926 
  1927 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1928 are similar to SUBPROOF, but are slightly more flexible: only the
  1929 specified parts of the subgoal are imported into the context, and the
  1930 body tactic may introduce new subgoals and schematic variables.
  1931 
  1932 * Old tactical METAHYPS, which does not observe the proof context, has
  1933 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1934 or Subgoal.FOCUS etc.
  1935 
  1936 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1937 functors have their own ML name space there is no point to mark them
  1938 separately.)  Minor INCOMPATIBILITY.
  1939 
  1940 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1941 
  1942 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1943 INCOMPATIBILITY.
  1944 
  1945 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1946 mode, which avoids critical setmp.
  1947 
  1948 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1949 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1950 Attrib/Method.setup introduced in Isabelle2009.
  1951 
  1952 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1953 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1954 last resort.  INCOMPATIBILITY.
  1955 
  1956 * Display.pretty_thm now requires a proper context (cf. former
  1957 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1958 or even Display.pretty_thm_without_context as last resort.
  1959 INCOMPATIBILITY.
  1960 
  1961 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1962 Syntax.pretty_typ/term directly, preferably with proper context
  1963 instead of global theory.
  1964 
  1965 
  1966 *** System ***
  1967 
  1968 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1969 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1970 usedir option -q.
  1971 
  1972 * Support for additional "Isabelle components" via etc/components, see
  1973 also the system manual.
  1974 
  1975 * The isabelle makeall tool now operates on all components with
  1976 IsaMakefile, not just hardwired "logics".
  1977 
  1978 * Removed "compress" option from isabelle-process and isabelle usedir;
  1979 this is always enabled.
  1980 
  1981 * Discontinued support for Poly/ML 4.x versions.
  1982 
  1983 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1984 on a given logic image.  This requires the lighttpd webserver and is
  1985 currently supported on Linux only.
  1986 
  1987 
  1988 
  1989 New in Isabelle2009 (April 2009)
  1990 --------------------------------
  1991 
  1992 *** General ***
  1993 
  1994 * Simplified main Isabelle executables, with less surprises on
  1995 case-insensitive file-systems (such as Mac OS).
  1996 
  1997   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1998     "isatool."
  1999 
  2000   - The former "isabelle" alias for "isabelle-process" has been
  2001     removed (should rarely occur to regular users).
  2002 
  2003   - The former "isabelle-interface" and its alias "Isabelle" have been
  2004     removed (interfaces are now regular Isabelle tools).
  2005 
  2006 Within scripts and make files, the Isabelle environment variables
  2007 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2008 respectively.  (The latter are still available as legacy feature.)
  2009 
  2010 The old isabelle-interface wrapper could react in confusing ways if
  2011 the interface was uninstalled or changed otherwise.  Individual
  2012 interface tool configuration is now more explicit, see also the
  2013 Isabelle system manual.  In particular, Proof General is now available
  2014 via "isabelle emacs".
  2015 
  2016 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2017 purge installed copies of Isabelle executables and re-run "isabelle
  2018 install -p ...", or use symlinks.
  2019 
  2020 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2021 old ~/isabelle, which was slightly non-standard and apt to cause
  2022 surprises on case-insensitive file-systems (such as Mac OS).
  2023 
  2024 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2025 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2026 care is required when using older releases of Isabelle.  Note that
  2027 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2028 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2029 
  2030 * Proofs of fully specified statements are run in parallel on
  2031 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2032 a regular 4-core machine, if the initial heap space is made reasonably
  2033 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2034 
  2035 * The main reference manuals ("isar-ref", "implementation", and
  2036 "system") have been updated and extended.  Formally checked references
  2037 as hyperlinks are now available uniformly.
  2038 
  2039 
  2040 *** Pure ***
  2041 
  2042 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2043 respects.  The most important changes are listed below.  See the
  2044 Tutorial on Locales ("locales" manual) for details.
  2045 
  2046 - In locale expressions, instantiation replaces renaming.  Parameters
  2047 must be declared in a for clause.  To aid compatibility with previous
  2048 parameter inheritance, in locale declarations, parameters that are not
  2049 'touched' (instantiation position "_" or omitted) are implicitly added
  2050 with their syntax at the beginning of the for clause.
  2051 
  2052 - Syntax from abbreviations and definitions in locales is available in
  2053 locale expressions and context elements.  The latter is particularly
  2054 useful in locale declarations.
  2055 
  2056 - More flexible mechanisms to qualify names generated by locale
  2057 expressions.  Qualifiers (prefixes) may be specified in locale
  2058 expressions, and can be marked as mandatory (syntax: "name!:") or
  2059 optional (syntax "name?:").  The default depends for plain "name:"
  2060 depends on the situation where a locale expression is used: in
  2061 commands 'locale' and 'sublocale' prefixes are optional, in
  2062 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2063 implicit qualifiers derived from the parameter names of a locale are
  2064 no longer generated.
  2065 
  2066 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2067 instantiation clause in "interpretation" and "interpret" (square
  2068 brackets) is no longer available.  Use locale expressions.
  2069 
  2070 - When converting proof scripts, mandatory qualifiers in
  2071 'interpretation' and 'interpret' should be retained by default, even
  2072 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2073 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2074 in locale expressions range over a single locale instance only.
  2075 
  2076 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2077 In existing theorem specifications replace the includes element by the
  2078 respective context elements of the included locale, omitting those
  2079 that are already present in the theorem specification.  Multiple
  2080 assume elements of a locale should be replaced by a single one
  2081 involving the locale predicate.  In the proof body, declarations (most
  2082 notably theorems) may be regained by interpreting the respective
  2083 locales in the proof context as required (command "interpret").
  2084 
  2085 If using "includes" in replacement of a target solely because the
  2086 parameter types in the theorem are not as general as in the target,
  2087 consider declaring a new locale with additional type constraints on
  2088 the parameters (context element "constrains").
  2089 
  2090 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2091 
  2092 - Locale interpretation commands no longer attempt to simplify goal.
  2093 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2094 methods intro_locales and unfold_locales to clarify.
  2095 
  2096 - Locale interpretation commands no longer accept interpretation
  2097 attributes.  INCOMPATIBILITY.
  2098 
  2099 * Class declaration: so-called "base sort" must not be given in import
  2100 list any longer, but is inferred from the specification.  Particularly
  2101 in HOL, write
  2102 
  2103     class foo = ...
  2104 
  2105 instead of
  2106 
  2107     class foo = type + ...
  2108 
  2109 * Class target: global versions of theorems stemming do not carry a
  2110 parameter prefix any longer.  INCOMPATIBILITY.
  2111 
  2112 * Class 'instance' command no longer accepts attached definitions.
  2113 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2114 
  2115 * Recovered hiding of consts, which was accidentally broken in
  2116 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2117 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2118 
  2119 * Slightly more coherent Pure syntax, with updated documentation in
  2120 isar-ref manual.  Removed locales meta_term_syntax and
  2121 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2122 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2123 directly in regular applications.
  2124 
  2125 * There is a new syntactic category "float_const" for signed decimal
  2126 fractions (e.g. 123.45 or -123.45).
  2127 
  2128 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2129 interface with 'setup' command instead.
  2130 
  2131 * Command 'local_setup' is similar to 'setup', but operates on a local
  2132 theory context.
  2133 
  2134 * The 'axiomatization' command now only works within a global theory
  2135 context.  INCOMPATIBILITY.
  2136 
  2137 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2138 hypotheses.  Sorts required in the course of reasoning need to be
  2139 covered by the constraints in the initial statement, completed by the
  2140 type instance information of the background theory.  Non-trivial sort
  2141 hypotheses, which rarely occur in practice, may be specified via
  2142 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2143 
  2144   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2145 
  2146 The result contains an implicit sort hypotheses as before --
  2147 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2148 normalization.
  2149 
  2150 * Generalized Isar history, with support for linear undo, direct state
  2151 addressing etc.
  2152 
  2153 * Changed defaults for unify configuration options:
  2154 
  2155   unify_trace_bound = 50 (formerly 25)
  2156   unify_search_bound = 60 (formerly 30)
  2157 
  2158 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2159 
  2160   a) On theory merge, the last set of code equations for a particular
  2161      constant is taken (in accordance with the policy applied by other
  2162      parts of the code generator framework).
  2163 
  2164   b) Code equations stemming from explicit declarations (e.g. code
  2165      attribute) gain priority over default code equations stemming
  2166      from definition, primrec, fun etc.
  2167 
  2168 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2169 
  2170 * Unified theorem tables for both code generators.  Thus [code
  2171 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2172 
  2173 * Command 'find_consts' searches for constants based on type and name
  2174 patterns, e.g.
  2175 
  2176     find_consts "_ => bool"
  2177 
  2178 By default, matching is against subtypes, but it may be restricted to
  2179 the whole type.  Searching by name is possible.  Multiple queries are
  2180 conjunctive and queries may be negated by prefixing them with a
  2181 hyphen:
  2182 
  2183     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2184 
  2185 * New 'find_theorems' criterion "solves" matches theorems that
  2186 directly solve the current goal (modulo higher-order unification).
  2187 
  2188 * Auto solve feature for main theorem statements: whenever a new goal
  2189 is stated, "find_theorems solves" is called; any theorems that could
  2190 solve the lemma directly are listed as part of the goal state.
  2191 Cf. associated options in Proof General Isabelle settings menu,
  2192 enabled by default, with reasonable timeout for pathological cases of
  2193 higher-order unification.
  2194 
  2195 
  2196 *** Document preparation ***
  2197 
  2198 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2199 demanding keyword 'by' and supporting the full method expression
  2200 syntax just like the Isar command 'by'.
  2201 
  2202 
  2203 *** HOL ***
  2204 
  2205 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2206 points Main and Complex_Main remain as before.
  2207 
  2208 * Logic image HOL-Plain provides a minimal HOL with the most important
  2209 tools available (inductive, datatype, primrec, ...).  This facilitates
  2210 experimentation and tool development.  Note that user applications
  2211 (and library theories) should never refer to anything below theory
  2212 Main, as before.
  2213 
  2214 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2215 experimentation due to shorter build times.
  2216 
  2217 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2218 were previously part of former HOL-Complex.  Entry point Hyperreal
  2219 remains valid, but theories formerly using Complex_Main should now use
  2220 new entry point Hypercomplex.
  2221 
  2222 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2223 Posix processes.  Avoids potentially expensive forking of the ML
  2224 process.  New thread-based implementation also works on non-Unix
  2225 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2226 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2227 commands are covered in the isar-ref manual.
  2228 
  2229 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2230 sledgehammer without local ATP installation (Vampire etc.). Other
  2231 provers may be included via suitable ML wrappers, see also
  2232 src/HOL/ATP_Linkup.thy.
  2233 
  2234 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2235 menu.
  2236 
  2237 * The metis method no longer fails because the theorem is too trivial
  2238 (contains the empty clause).
  2239 
  2240 * The metis method now fails in the usual manner, rather than raising
  2241 an exception, if it determines that it cannot prove the theorem.
  2242 
  2243 * Method "coherent" implements a prover for coherent logic (see also
  2244 src/Tools/coherent.ML).
  2245 
  2246 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2247 "undefined" is the right choice to replace "arbitrary", though
  2248 logically there is no difference.  INCOMPATIBILITY.
  2249 
  2250 * Command "value" now integrates different evaluation mechanisms.  The
  2251 result of the first successful evaluation mechanism is printed.  In
  2252 square brackets a particular named evaluation mechanisms may be
  2253 specified (currently, [SML], [code] or [nbe]).  See further
  2254 src/HOL/ex/Eval_Examples.thy.
  2255 
  2256 * Normalization by evaluation now allows non-leftlinear equations.
  2257 Declare with attribute [code nbe].
  2258 
  2259 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2260 as the structured Isar versions "cases" and "induct", cf. the
  2261 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2262 are now presented as a list of individual projections
  2263 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2264 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2265 rare situations a different rule is selected --- notably nested tuple
  2266 elimination instead of former prod.exhaust: use explicit (case_tac t
  2267 rule: prod.exhaust) here.
  2268 
  2269 * Attributes "cases", "induct", "coinduct" support "del" option.
  2270 
  2271 * Removed fact "case_split_thm", which duplicates "case_split".
  2272 
  2273 * The option datatype has been moved to a new theory Option.  Renamed
  2274 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2275 
  2276 * New predicate "strict_mono" classifies strict functions on partial
  2277 orders.  With strict functions on linear orders, reasoning about
  2278 (in)equalities is facilitated by theorems "strict_mono_eq",
  2279 "strict_mono_less_eq" and "strict_mono_less".
  2280 
  2281 * Some set operations are now proper qualified constants with
  2282 authentic syntax.  INCOMPATIBILITY:
  2283 
  2284     op Int ~>   Set.Int
  2285     op Un ~>    Set.Un
  2286     INTER ~>    Set.INTER
  2287     UNION ~>    Set.UNION
  2288     Inter ~>    Set.Inter
  2289     Union ~>    Set.Union
  2290     {} ~>       Set.empty
  2291     UNIV ~>     Set.UNIV
  2292 
  2293 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2294 theory Set.
  2295 
  2296 * Auxiliary class "itself" has disappeared -- classes without any
  2297 parameter are treated as expected by the 'class' command.
  2298 
  2299 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2300 
  2301 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2302 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2303 
  2304 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2305 method "approximation".  It proves formulas on real values by using
  2306 interval arithmetic.  In the formulas are also the transcendental
  2307 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2308 allowed. For examples see
  2309 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2310 
  2311 * Theory "Reflection" now resides in HOL/Library.
  2312 
  2313 * Entry point to Word library now simply named "Word".
  2314 INCOMPATIBILITY.
  2315 
  2316 * Made source layout more coherent with logical distribution
  2317 structure:
  2318 
  2319     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2320     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2321     src/HOL/Library/GCD.thy ~> src/HOL/
  2322     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2323     src/HOL/Library/Parity.thy ~> src/HOL/
  2324     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2325     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2326     src/HOL/Real/Lubs.thy ~> src/HOL/
  2327     src/HOL/Real/PReal.thy ~> src/HOL/
  2328     src/HOL/Real/Rational.thy ~> src/HOL/
  2329     src/HOL/Real/RComplete.thy ~> src/HOL/
  2330     src/HOL/Real/RealDef.thy ~> src/HOL/
  2331     src/HOL/Real/RealPow.thy ~> src/HOL/
  2332     src/HOL/Real/Real.thy ~> src/HOL/
  2333     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2334     src/HOL/Complex/Complex.thy ~> src/HOL/
  2335     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2336     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2337     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2338     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2339     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2340     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2341     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2342     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2343     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2344     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2345     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2346     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2347     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2348     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2349     src/HOL/Real/Float ~> src/HOL/Library/
  2350     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2351     src/HOL/Real/RealVector.thy ~> src/HOL/
  2352 
  2353     src/HOL/arith_data.ML ~> src/HOL/Tools
  2354     src/HOL/hologic.ML ~> src/HOL/Tools
  2355     src/HOL/simpdata.ML ~> src/HOL/Tools
  2356     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2357     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2358     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2359     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2360     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2361     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2362     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2363 
  2364     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2365     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2366     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2367     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2368     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2369     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2370 
  2371 * If methods "eval" and "evaluation" encounter a structured proof
  2372 state with !!/==>, only the conclusion is evaluated to True (if
  2373 possible), avoiding strange error messages.
  2374 
  2375 * Method "sizechange" automates termination proofs using (a
  2376 modification of) the size-change principle.  Requires SAT solver.  See
  2377 src/HOL/ex/Termination.thy for examples.
  2378 
  2379 * Simplifier: simproc for let expressions now unfolds if bound
  2380 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2381 
  2382 * Method "arith": Linear arithmetic now ignores all inequalities when
  2383 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2384 
  2385 * New attribute "arith" for facts that should always be used
  2386 automatically by arithmetic. It is intended to be used locally in
  2387 proofs, e.g.
  2388 
  2389   assumes [arith]: "x > 0"
  2390 
  2391 Global usage is discouraged because of possible performance impact.
  2392 
  2393 * New classes "top" and "bot" with corresponding operations "top" and
  2394 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2395 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2396 
  2397 * Changed definition lemma "less_fun_def" in order to provide an
  2398 instance for preorders on functions; use lemma "less_le" instead.
  2399 INCOMPATIBILITY.
  2400 
  2401 * Theory Orderings: class "wellorder" moved here, with explicit
  2402 induction rule "less_induct" as assumption.  For instantiation of
  2403 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2404 INCOMPATIBILITY.
  2405 
  2406 * Theory Orderings: added class "preorder" as superclass of "order".
  2407 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2408 etc. slightly changed.  Some theorems named order_class.* now named
  2409 preorder_class.*.
  2410 
  2411 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2412 "diag" to "Id_on".
  2413 
  2414 * Theory Finite_Set: added a new fold combinator of type
  2415 
  2416   ('a => 'b => 'b) => 'b => 'a set => 'b
  2417 
  2418 Occasionally this is more convenient than the old fold combinator
  2419 which is now defined in terms of the new one and renamed to
  2420 fold_image.
  2421 
  2422 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2423 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2424 extended with further lemmas!).  At the moment both still exist but
  2425 the former will disappear at some point.
  2426 
  2427 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2428 class recpower.  Type-specific simp rules for various recpower types
  2429 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2430 
  2431 rat_power_0    -> power_0
  2432 rat_power_Suc  -> power_Suc
  2433 realpow_0      -> power_0
  2434 realpow_Suc    -> power_Suc
  2435 complexpow_0   -> power_0
  2436 complexpow_Suc -> power_Suc
  2437 power_poly_0   -> power_0
  2438 power_poly_Suc -> power_Suc
  2439 
  2440 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2441 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2442 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2443 of lemmas from Divides has been generalized from nat to class
  2444 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2445 renames resulting from duplicate elimination:
  2446 
  2447     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2448     zero_dvd_iff ~>         dvd_0_left_iff
  2449     dvd_0 ~>                dvd_0_right
  2450     DIVISION_BY_ZERO_DIV ~> div_by_0
  2451     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2452     mult_div ~>             div_mult_self2_is_id
  2453     mult_mod ~>             mod_mult_self2_is_0
  2454 
  2455 * Theory IntDiv: removed many lemmas that are instances of class-based
  2456 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2457 rename old lemmas as follows:
  2458 
  2459 dvd_diff               -> nat_dvd_diff
  2460 dvd_zminus_iff         -> dvd_minus_iff
  2461 mod_add1_eq            -> mod_add_eq
  2462 mod_mult1_eq           -> mod_mult_right_eq
  2463 mod_mult1_eq'          -> mod_mult_left_eq
  2464 mod_mult_distrib_mod   -> mod_mult_eq
  2465 nat_mod_add_left_eq    -> mod_add_left_eq
  2466 nat_mod_add_right_eq   -> mod_add_right_eq
  2467 nat_mod_div_trivial    -> mod_div_trivial
  2468 nat_mod_mod_trivial    -> mod_mod_trivial
  2469 zdiv_zadd_self1        -> div_add_self1
  2470 zdiv_zadd_self2        -> div_add_self2
  2471 zdiv_zmult_self1       -> div_mult_self2_is_id
  2472 zdiv_zmult_self2       -> div_mult_self1_is_id
  2473 zdvd_triv_left         -> dvd_triv_left
  2474 zdvd_triv_right        -> dvd_triv_right
  2475 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2476 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2477 zmod_zadd_left_eq      -> mod_add_left_eq
  2478 zmod_zadd_right_eq     -> mod_add_right_eq
  2479 zmod_zadd_self1        -> mod_add_self1
  2480 zmod_zadd_self2        -> mod_add_self2
  2481 zmod_zadd1_eq          -> mod_add_eq
  2482 zmod_zdiff1_eq         -> mod_diff_eq
  2483 zmod_zdvd_zmod         -> mod_mod_cancel
  2484 zmod_zmod_cancel       -> mod_mod_cancel
  2485 zmod_zmult_self1       -> mod_mult_self2_is_0
  2486 zmod_zmult_self2       -> mod_mult_self1_is_0
  2487 zmod_1                 -> mod_by_1
  2488 zdiv_1                 -> div_by_1
  2489 zdvd_abs1              -> abs_dvd_iff
  2490 zdvd_abs2              -> dvd_abs_iff
  2491 zdvd_refl              -> dvd_refl
  2492 zdvd_trans             -> dvd_trans
  2493 zdvd_zadd              -> dvd_add
  2494 zdvd_zdiff             -> dvd_diff
  2495 zdvd_zminus_iff        -> dvd_minus_iff
  2496 zdvd_zminus2_iff       -> minus_dvd_iff
  2497 zdvd_zmultD            -> dvd_mult_right
  2498 zdvd_zmultD2           -> dvd_mult_left
  2499 zdvd_zmult_mono        -> mult_dvd_mono
  2500 zdvd_0_right           -> dvd_0_right
  2501 zdvd_0_left            -> dvd_0_left_iff
  2502 zdvd_1_left            -> one_dvd
  2503 zminus_dvd_iff         -> minus_dvd_iff
  2504 
  2505 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2506 
  2507 * The real numbers offer decimal input syntax: 12.34 is translated
  2508 into 1234/10^2. This translation is not reversed upon output.
  2509 
  2510 * Theory Library/Polynomial defines an abstract type 'a poly of
  2511 univariate polynomials with coefficients of type 'a.  In addition to
  2512 the standard ring operations, it also supports div and mod.  Code
  2513 generation is also supported, using list-style constructors.
  2514 
  2515 * Theory Library/Inner_Product defines a class of real_inner for real
  2516 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2517 => real.  Class real_inner is a subclass of real_normed_vector from
  2518 theory RealVector.
  2519 
  2520 * Theory Library/Product_Vector provides instances for the product
  2521 type 'a * 'b of several classes from RealVector and Inner_Product.
  2522 Definitions of addition, subtraction, scalar multiplication, norms,
  2523 and inner products are included.
  2524 
  2525 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2526 addition to the field operations, numerals and case syntax are also
  2527 supported.
  2528 
  2529 * Theory Library/Diagonalize provides constructive version of Cantor's
  2530 first diagonalization argument.
  2531 
  2532 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2533 zlcm (for int); carried together from various gcd/lcm developements in
  2534 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2535 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2536 may recover tupled syntax as follows:
  2537 
  2538     hide (open) const gcd
  2539     abbreviation gcd where
  2540       "gcd == (%(a, b). GCD.gcd a b)"
  2541     notation (output)
  2542       GCD.gcd ("gcd '(_, _')")
  2543 
  2544 The same works for lcm, zgcd, zlcm.
  2545 
  2546 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2547 instantiations for algebraic structures.  Removed some duplicate
  2548 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2549 
  2550 * ML antiquotation @{code} takes a constant as argument and generates
  2551 corresponding code in background and inserts name of the corresponding
  2552 resulting ML value/function/datatype constructor binding in place.
  2553 All occurrences of @{code} with a single ML block are generated
  2554 simultaneously.  Provides a generic and safe interface for
  2555 instrumentalizing code generation.  See
  2556 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2557 In future you ought to refrain from ad-hoc compiling generated SML
  2558 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2559 cannot refer to constants for which user-defined serializations are
  2560 set.  Refer to the corresponding ML counterpart directly in that
  2561 cases.
  2562 
  2563 * Command 'rep_datatype': instead of theorem names the command now
  2564 takes a list of terms denoting the constructors of the type to be
  2565 represented as datatype.  The characteristic theorems have to be
  2566 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2567 have disappeared in favour of existing ones:
  2568 
  2569     unit_induct                 ~> unit.induct
  2570     prod_induct                 ~> prod.induct
  2571     sum_induct                  ~> sum.induct
  2572     Suc_Suc_eq                  ~> nat.inject
  2573     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2574 
  2575 
  2576 *** HOL-Algebra ***
  2577 
  2578 * New locales for orders and lattices where the equivalence relation
  2579 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2580 locales use a record structure with field eq for the equivalence.
  2581 
  2582 * New theory of factorial domains.
  2583 
  2584 * Units_l_inv and Units_r_inv are now simp rules by default.
  2585 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2586 and/or r_inv will now also require deletion of these lemmas.
  2587 
  2588 * Renamed the following theorems, INCOMPATIBILITY:
  2589 
  2590 UpperD ~> Upper_memD
  2591 LowerD ~> Lower_memD
  2592 least_carrier ~> least_closed
  2593 greatest_carrier ~> greatest_closed
  2594 greatest_Lower_above ~> greatest_Lower_below
  2595 one_zero ~> carrier_one_zero
  2596 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2597 
  2598 
  2599 *** HOL-Nominal ***
  2600 
  2601 * Nominal datatypes can now contain type-variables.
  2602 
  2603 * Commands 'nominal_inductive' and 'equivariance' work with local
  2604 theory targets.
  2605 
  2606 * Nominal primrec can now works with local theory targets and its
  2607 specification syntax now conforms to the general format as seen in
  2608 'inductive' etc.
  2609 
  2610 * Method "perm_simp" honours the standard simplifier attributes
  2611 (no_asm), (no_asm_use) etc.
  2612 
  2613 * The new predicate #* is defined like freshness, except that on the
  2614 left hand side can be a set or list of atoms.
  2615 
  2616 * Experimental command 'nominal_inductive2' derives strong induction
  2617 principles for inductive definitions.  In contrast to
  2618 'nominal_inductive', which can only deal with a fixed number of
  2619 binders, it can deal with arbitrary expressions standing for sets of
  2620 atoms to be avoided.  The only inductive definition we have at the
  2621 moment that needs this generalisation is the typing rule for Lets in
  2622 the algorithm W:
  2623 
  2624  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2625  -----------------------------------------------------------------
  2626          Gamma |- Let x be t1 in t2 : T2
  2627 
  2628 In this rule one wants to avoid all the binders that are introduced by
  2629 "close Gamma T1".  We are looking for other examples where this
  2630 feature might be useful.  Please let us know.
  2631 
  2632 
  2633 *** HOLCF ***
  2634 
  2635 * Reimplemented the simplification procedure for proving continuity
  2636 subgoals.  The new simproc is extensible; users can declare additional
  2637 continuity introduction rules with the attribute [cont2cont].
  2638 
  2639 * The continuity simproc now uses a different introduction rule for
  2640 solving continuity subgoals on terms with lambda abstractions.  In
  2641 some rare cases the new simproc may fail to solve subgoals that the
  2642 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2643 Potential INCOMPATIBILITY.
  2644 
  2645 * Command 'fixrec': specification syntax now conforms to the general
  2646 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2647 examples.  INCOMPATIBILITY.
  2648 
  2649 
  2650 *** ZF ***
  2651 
  2652 * Proof of Zorn's Lemma for partial orders.
  2653 
  2654 
  2655 *** ML ***
  2656 
  2657 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2658 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2659 depends on multithreading, so timouts will not work before Poly/ML
  2660 5.2.1!
  2661 
  2662 * High-level support for concurrent ML programming, see
  2663 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2664 particularly convenient to organize independent functional
  2665 computations.  The concept of "synchronized variables" provides a
  2666 higher-order interface for components with shared state, avoiding the
  2667 delicate details of mutexes and condition variables.  (Requires
  2668 Poly/ML 5.2.1 or later.)
  2669 
  2670 * ML bindings produced via Isar commands are stored within the Isar
  2671 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2672 become thread-safe and work with undo as expected (concerning
  2673 top-level bindings, not side-effects on global references).
  2674 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2675 compiler at runtime; really global bindings need to be given outside a
  2676 theory.  (Requires Poly/ML 5.2 or later.)
  2677 
  2678 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2679 context.  Top-level ML bindings are stored within the proof context in
  2680 a purely sequential fashion, disregarding the nested proof structure.
  2681 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2682 proof.  (Requires Poly/ML 5.2 or later.)
  2683 
  2684 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2685 and Method.setup, as well as Isar commands 'attribute_setup' and
  2686 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2687 existing code accordingly, or use plain 'setup' together with old
  2688 Method.add_method.
  2689 
  2690 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2691 to 'a -> thm, while results are always tagged with an authentic oracle
  2692 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2693 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2694 accordingly.  Note that extra performance may be gained by producing
  2695 the cterm carefully, avoiding slow Thm.cterm_of.
  2696 
  2697 * Simplified interface for defining document antiquotations via
  2698 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2699 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2700 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2701 examples.
  2702 
  2703 * More systematic treatment of long names, abstract name bindings, and
  2704 name space operations.  Basic operations on qualified names have been
  2705 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2706 Long_Name.append.  Old type bstring has been mostly replaced by
  2707 abstract type binding (see structure Binding), which supports precise
  2708 qualification by packages and local theory targets, as well as proper
  2709 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2710 bstring values into Binding.name, or better pass through abstract
  2711 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2712 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2713 
  2714 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2715 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2716 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2717 
  2718 * Disposed old type and term read functions (Sign.read_def_typ,
  2719 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2720 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2721 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2722 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2723 resort for legacy applications.
  2724 
  2725 * Disposed old declarations, tactics, tactic combinators that refer to
  2726 the simpset or claset of an implicit theory (such as Addsimps,
  2727 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2728 embedded ML text, or local_simpset_of with a proper context passed as
  2729 explicit runtime argument.
  2730 
  2731 * Rules and tactics that read instantiations (read_instantiate,
  2732 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2733 context, which is required for parsing and type-checking.  Moreover,
  2734 the variables are specified as plain indexnames, not string encodings
  2735 thereof.  INCOMPATIBILITY.
  2736 
  2737 * Generic Toplevel.add_hook interface allows to analyze the result of
  2738 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2739 for theorem dependency output of transactions resulting in a new
  2740 theory state.
  2741 
  2742 * ML antiquotations: block-structured compilation context indicated by
  2743 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2744 
  2745   @{binding name}                         - basic name binding
  2746   @{let ?pat = term}                      - term abbreviation (HO matching)
  2747   @{note name = fact}                     - fact abbreviation
  2748   @{thm fact}                             - singleton fact (with attributes)
  2749   @{thms fact}                            - general fact (with attributes)
  2750   @{lemma prop by method}                 - singleton goal
  2751   @{lemma prop by meth1 meth2}            - singleton goal
  2752   @{lemma prop1 ... propN by method}      - general goal
  2753   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2754   @{lemma (open) ...}                     - open derivation
  2755 
  2756 
  2757 *** System ***
  2758 
  2759 * The Isabelle "emacs" tool provides a specific interface to invoke
  2760 Proof General / Emacs, with more explicit failure if that is not
  2761 installed (the old isabelle-interface script silently falls back on
  2762 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2763 installation location of the Proof General distribution.
  2764 
  2765 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2766 the Isabelle process into a JVM/Scala application.  See
  2767 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2768 process wrapper has been discontinued.)
  2769 
  2770 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2771 
  2772 * Various status messages (with exact source position information) are
  2773 emitted, if proper markup print mode is enabled.  This allows
  2774 user-interface components to provide detailed feedback on internal
  2775 prover operations.
  2776 
  2777 
  2778 
  2779 New in Isabelle2008 (June 2008)
  2780 -------------------------------
  2781 
  2782 *** General ***
  2783 
  2784 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2785 and updated, with formally checked references as hyperlinks.
  2786 
  2787 * Theory loader: use_thy (and similar operations) no longer set the
  2788 implicit ML context, which was occasionally hard to predict and in
  2789 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2790 provides a proper context already.
  2791 
  2792 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2793 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2794 'use' within a theory file will do the job.
  2795 
  2796 * Name space merge now observes canonical order, i.e. the second space
  2797 is inserted into the first one, while existing entries in the first
  2798 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2799 swap theory imports.
  2800 
  2801 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2802 INCOMPATIBILITY in identifier syntax etc.
  2803 
  2804 * Outer syntax: string tokens no longer admit escaped white space,
  2805 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2806 white space without escapes.
  2807 
  2808 * Outer syntax: string tokens may contain arbitrary character codes
  2809 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2810 "foo_bar".
  2811 
  2812 
  2813 *** Pure ***
  2814 
  2815 * Context-dependent token translations.  Default setup reverts locally
  2816 fixed variables, and adds hilite markup for undeclared frees.
  2817 
  2818 * Unused theorems can be found using the new command 'unused_thms'.
  2819 There are three ways of invoking it:
  2820 
  2821 (1) unused_thms
  2822      Only finds unused theorems in the current theory.
  2823 
  2824 (2) unused_thms thy_1 ... thy_n -
  2825      Finds unused theorems in the current theory and all of its ancestors,
  2826      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2827 
  2828 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2829      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2830      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2831      their ancestors.
  2832 
  2833 In order to increase the readability of the list produced by
  2834 unused_thms, theorems that have been created by a particular instance
  2835 of a theory command such as 'inductive' or 'function' are considered
  2836 to belong to the same "group", meaning that if at least one theorem in
  2837 this group is used, the other theorems in the same group are no longer
  2838 reported as unused.  Moreover, if all theorems in the group are
  2839 unused, only one theorem in the group is displayed.
  2840 
  2841 Note that proof objects have to be switched on in order for
  2842 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2843 usually the case when using Proof General with the default settings).
  2844 
  2845 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2846 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2847 duplicate fact bindings, or even accidental fact duplications.  Note
  2848 that tools may maintain dynamically scoped facts systematically, using
  2849 PureThy.add_thms_dynamic.
  2850 
  2851 * Command 'hide' now allows to hide from "fact" name space as well.
  2852 
  2853 * Eliminated destructive theorem database, simpset, claset, and
  2854 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2855 update of theories within ML code.
  2856 
  2857 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2858 INCOMPATIBILITY, object-logics depending on former Pure require
  2859 additional setup PureThy.old_appl_syntax_setup; object-logics
  2860 depending on former CPure need to refer to Pure.
  2861 
  2862 * Commands 'use' and 'ML' are now purely functional, operating on
  2863 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2864 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2865 INCOMPATIBILITY.
  2866 
  2867 * Command 'setup': discontinued implicit version with ML reference.
  2868 
  2869 * Instantiation target allows for simultaneous specification of class
  2870 instance operations together with an instantiation proof.
  2871 Type-checking phase allows to refer to class operations uniformly.
  2872 See src/HOL/Complex/Complex.thy for an Isar example and
  2873 src/HOL/Library/Eval.thy for an ML example.
  2874 
  2875 * Indexing of literal facts: be more serious about including only
  2876 facts from the visible specification/proof context, but not the
  2877 background context (locale etc.).  Affects `prop` notation and method
  2878 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2879 situations.
  2880 
  2881 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2882 "(open)" option, which used to expose internal bound variables to the
  2883 proof text.
  2884 
  2885 * Isar statements: removed obsolete case "rule_context".
  2886 INCOMPATIBILITY, better use explicit fixes/assumes.
  2887 
  2888 * Locale proofs: default proof step now includes 'unfold_locales';
  2889 hence 'proof' without argument may be used to unfold locale
  2890 predicates.
  2891 
  2892 
  2893 *** Document preparation ***
  2894 
  2895 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2896 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2897 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2898 spot); renamed link color from "darkblue" to "linkcolor" (default
  2899 value unchanged, can be redefined via \definecolor); no longer sets
  2900 "a4paper" option (unnecessary or even intrusive).
  2901 
  2902 * Antiquotation @{lemma A method} proves proposition A by the given
  2903 method (either a method name or a method name plus (optional) method
  2904 arguments in parentheses) and prints A just like @{prop A}.
  2905 
  2906 
  2907 *** HOL ***
  2908 
  2909 * New primrec package.  Specification syntax conforms in style to
  2910 definition/function/....  No separate induction rule is provided.  The
  2911 "primrec" command distinguishes old-style and new-style specifications
  2912 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2913 When adjusting theories, beware: constants stemming from new-style
  2914 primrec specifications have authentic syntax.
  2915 
  2916 * Metis prover is now an order of magnitude faster, and also works
  2917 with multithreading.
  2918 
  2919 * Metis: the maximum number of clauses that can be produced from a
  2920 theorem is now given by the attribute max_clauses.  Theorems that
  2921 exceed this number are ignored, with a warning printed.
  2922 
  2923 * Sledgehammer no longer produces structured proofs by default. To
  2924 enable, declare [[sledgehammer_full = true]].  Attributes
  2925 reconstruction_modulus, reconstruction_sorts renamed
  2926 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2927 
  2928 * Method "induct_scheme" derives user-specified induction rules
  2929 from well-founded induction and completeness of patterns. This factors
  2930 out some operations that are done internally by the function package
  2931 and makes them available separately.  See
  2932 src/HOL/ex/Induction_Scheme.thy for examples.
  2933 
  2934 * More flexible generation of measure functions for termination
  2935 proofs: Measure functions can be declared by proving a rule of the
  2936 form "is_measure f" and giving it the [measure_function] attribute.
  2937 The "is_measure" predicate is logically meaningless (always true), and
  2938 just guides the heuristic.  To find suitable measure functions, the
  2939 termination prover sets up the goal "is_measure ?f" of the appropriate
  2940 type and generates all solutions by prolog-style backwards proof using
  2941 the declared rules.
  2942 
  2943 This setup also deals with rules like 
  2944 
  2945   "is_measure f ==> is_measure (list_size f)"
  2946 
  2947 which accommodates nested datatypes that recurse through lists.
  2948 Similar rules are predeclared for products and option types.
  2949 
  2950 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2951 
  2952   INCOMPATIBILITIES:
  2953 
  2954   - Definitions of overloaded constants on sets have to be replaced by
  2955     definitions on => and bool.
  2956 
  2957   - Some definitions of overloaded operators on sets can now be proved
  2958     using the definitions of the operators on => and bool.  Therefore,
  2959     the following theorems have been renamed:
  2960 
  2961       subset_def   -> subset_eq
  2962       psubset_def  -> psubset_eq
  2963       set_diff_def -> set_diff_eq
  2964       Compl_def    -> Compl_eq
  2965       Sup_set_def  -> Sup_set_eq
  2966       Inf_set_def  -> Inf_set_eq
  2967       sup_set_def  -> sup_set_eq
  2968       inf_set_def  -> inf_set_eq
  2969 
  2970   - Due to the incompleteness of the HO unification algorithm, some
  2971     rules such as subst may require manual instantiation, if some of
  2972     the unknowns in the rule is a set.
  2973 
  2974   - Higher order unification and forward proofs:
  2975     The proof pattern
  2976 
  2977       have "P (S::'a set)" <...>
  2978       then have "EX S. P S" ..
  2979 
  2980     no longer works (due to the incompleteness of the HO unification
  2981     algorithm) and must be replaced by the pattern
  2982 
  2983       have "EX S. P S"
  2984       proof
  2985         show "P S" <...>
  2986       qed
  2987 
  2988   - Calculational reasoning with subst (or similar rules):
  2989     The proof pattern
  2990 
  2991       have "P (S::'a set)" <...>
  2992       also have "S = T" <...>
  2993       finally have "P T" .
  2994 
  2995     no longer works (for similar reasons as the previous example) and
  2996     must be replaced by something like
  2997 
  2998       have "P (S::'a set)" <...>
  2999       moreover have "S = T" <...>
  3000       ultimately have "P T" by simp
  3001 
  3002   - Tactics or packages written in ML code:
  3003     Code performing pattern matching on types via
  3004 
  3005       Type ("set", [T]) => ...
  3006 
  3007     must be rewritten. Moreover, functions like strip_type or
  3008     binder_types no longer return the right value when applied to a
  3009     type of the form
  3010 
  3011       T1 => ... => Tn => U => bool
  3012 
  3013     rather than
  3014 
  3015       T1 => ... => Tn => U set
  3016 
  3017 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3018 Wellfounded_Relations to theory Wellfounded.
  3019 
  3020 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3021 
  3022 * Class finite no longer treats UNIV as class parameter.  Use class
  3023 enum from theory Library/Enum instead to achieve a similar effect.
  3024 INCOMPATIBILITY.
  3025 
  3026 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3027 and "Cons".  INCOMPATIBILITY.
  3028 
  3029 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3030 Potential INCOMPATIBILITY.
  3031 
  3032 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3033 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3034 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3035 
  3036 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3037 the same name in theory Orderings:
  3038 
  3039   less_trans
  3040   less_linear
  3041   le_imp_less_or_eq
  3042   le_less_trans
  3043   less_le_trans
  3044   less_not_sym
  3045   less_asym
  3046 
  3047 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3048 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3049 and different variable names.
  3050 
  3051 * Library/Option_ord.thy: Canonical order on option type.
  3052 
  3053 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3054 finite maps.
  3055 
  3056 * Library/Countable.thy: Type class for countable types.
  3057 
  3058 * Theory Int: The representation of numerals has changed.  The infix
  3059 operator BIT and the bit datatype with constructors B0 and B1 have
  3060 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3061 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3062 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3063 accordingly.
  3064 
  3065 * Theory Nat: definition of <= and < on natural numbers no longer
  3066 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3067 le_def and less_def have disappeared.  Consider lemmas not_less
  3068 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3069 
  3070 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3071 (whose purpose mainly is for various fold_set functionals) have been
  3072 abandoned in favor of the existing algebraic classes
  3073 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3074 lower_semilattice (resp. upper_semilattice) and linorder.
  3075 INCOMPATIBILITY.
  3076 
  3077 * Theory Transitive_Closure: induct and cases rules now declare proper
  3078 case_names ("base" and "step").  INCOMPATIBILITY.
  3079 
  3080 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3081 lattices.  The form set-specific version is available as
  3082 Inductive.lfp_ordinal_induct_set.
  3083 
  3084 * Renamed theorems "power.simps" to "power_int.simps".
  3085 INCOMPATIBILITY.
  3086 
  3087 * Class semiring_div provides basic abstract properties of semirings
  3088 with division and modulo operations.  Subsumes former class dvd_mod.
  3089 
  3090 * Merged theories IntDef, Numeral and IntArith into unified theory
  3091 Int.  INCOMPATIBILITY.
  3092 
  3093 * Theory Library/Code_Index: type "index" now represents natural
  3094 numbers rather than integers.  INCOMPATIBILITY.
  3095 
  3096 * New class "uminus" with operation "uminus" (split of from class
  3097 "minus" which now only has operation "minus", binary).
  3098 INCOMPATIBILITY.
  3099 
  3100 * Constants "card", "internal_split", "option_map" now with authentic
  3101 syntax.  INCOMPATIBILITY.
  3102 
  3103 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3104 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3105 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3106 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3107 Sup_set_def, le_def, less_def, option_map_def now with object
  3108 equality.  INCOMPATIBILITY.
  3109 
  3110 * Records. Removed K_record, and replaced it by pure lambda term
  3111 %x. c. The simplifier setup is now more robust against eta expansion.
  3112 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3113 
  3114 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3115 
  3116 * Library/ListVector: new theory of arithmetic vector operations.
  3117 
  3118 * Library/Order_Relation: new theory of various orderings as sets of
  3119 pairs.  Defines preorders, partial orders, linear orders and
  3120 well-orders on sets and on types.
  3121 
  3122 
  3123 *** ZF ***
  3124 
  3125 * Renamed some theories to allow to loading both ZF and HOL in the
  3126 same session:
  3127 
  3128   Datatype  -> Datatype_ZF
  3129   Inductive -> Inductive_ZF
  3130   Int       -> Int_ZF
  3131   IntDiv    -> IntDiv_ZF
  3132   Nat       -> Nat_ZF
  3133   List      -> List_ZF
  3134   Main      -> Main_ZF
  3135 
  3136 INCOMPATIBILITY: ZF theories that import individual theories below
  3137 Main might need to be adapted.  Regular theory Main is still
  3138 available, as trivial extension of Main_ZF.
  3139 
  3140 
  3141 *** ML ***
  3142 
  3143 * ML within Isar: antiquotation @{const name} or @{const
  3144 name(typargs)} produces statically-checked Const term.
  3145 
  3146 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3147 (of the same name).  Removed obsolete print command.
  3148 
  3149 * Removed obsolete "use_legacy_bindings" function.
  3150 
  3151 * The ``print mode'' is now a thread-local value derived from a global
  3152 template (the former print_mode reference), thus access becomes
  3153 non-critical.  The global print_mode reference is for session
  3154 management only; user-code should use print_mode_value,
  3155 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3156 
  3157 * Functions system/system_out provide a robust way to invoke external
  3158 shell commands, with propagation of interrupts (requires Poly/ML
  3159 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3160 
  3161 
  3162 *** System ***
  3163 
  3164 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3165 in accordance with Proof General 3.7, which prefers GNU emacs.
  3166 
  3167 * isatool tty runs Isabelle process with plain tty interaction;
  3168 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3169 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3170 
  3171 * isatool browser now works with Cygwin as well, using general
  3172 "javapath" function defined in Isabelle process environment.
  3173 
  3174 * YXML notation provides a simple and efficient alternative to
  3175 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3176 isatool yxml as described in the Isabelle system manual.
  3177 
  3178 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3179 provides general wrapper for managing an Isabelle process in a robust
  3180 fashion, with ``cooked'' output from stdin/stderr.
  3181 
  3182 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3183 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3184 
  3185 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3186 way of changing the user's settings is via
  3187 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3188 script.
  3189 
  3190 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3191 cores of the underlying machine, which is a good starting point for
  3192 optimal performance tuning.  The corresponding usedir option -M allows
  3193 "max" as an alias for "0".  WARNING: does not work on certain versions
  3194 of Mac OS (with Poly/ML 5.1).
  3195 
  3196 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3197 adverse effect of Isabelle flooding interactive front-ends (notably
  3198 ProofGeneral / XEmacs).
  3199 
  3200 
  3201 
  3202 New in Isabelle2007 (November 2007)
  3203 -----------------------------------
  3204 
  3205 *** General ***
  3206 
  3207 * More uniform information about legacy features, notably a
  3208 warning/error of "Legacy feature: ...", depending on the state of the
  3209 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3210 legacy features will disappear eventually.
  3211 
  3212 * Theory syntax: the header format ``theory A = B + C:'' has been
  3213 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3214 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3215 
  3216 * Theory syntax: the old non-Isar theory file format has been
  3217 discontinued altogether.  Note that ML proof scripts may still be used
  3218 with Isar theories; migration is usually quite simple with the ML
  3219 function use_legacy_bindings.  INCOMPATIBILITY.
  3220 
  3221 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3222 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3223 quotes.
  3224 
  3225 * Theory loader: be more serious about observing the static theory
  3226 header specifications (including optional directories), but not the
  3227 accidental file locations of previously successful loads.  The strict
  3228 update policy of former update_thy is now already performed by
  3229 use_thy, so the former has been removed; use_thys updates several
  3230 theories simultaneously, just as 'imports' within a theory header
  3231 specification, but without merging the results.  Potential
  3232 INCOMPATIBILITY: may need to refine theory headers and commands
  3233 ROOT.ML which depend on load order.
  3234 
  3235 * Theory loader: optional support for content-based file
  3236 identification, instead of the traditional scheme of full physical
  3237 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3238 (cf. the system manual).  The new scheme allows to work with
  3239 non-finished theories in persistent session images, such that source
  3240 files may be moved later on without requiring reloads.
  3241 
  3242 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3243 file (with the same base name as the theory) are considered a legacy
  3244 feature, which will disappear eventually. Even now, the theory loader
  3245 no longer maintains dependencies on such files.
  3246 
  3247 * Syntax: the scope for resolving ambiguities via type-inference is
  3248 now limited to individual terms, instead of whole simultaneous
  3249 specifications as before. This greatly reduces the complexity of the
  3250 syntax module and improves flexibility by separating parsing and
  3251 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3252 'fixes' etc.) are required in rare situations.
  3253 
  3254 * Syntax: constants introduced by new-style packages ('definition',
  3255 'abbreviation' etc.) are passed through the syntax module in
  3256 ``authentic mode''. This means that associated mixfix annotations
  3257 really stick to such constants, independently of potential name space
  3258 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3259 trees are represented slightly differently, may need to adapt syntax
  3260 translations accordingly. Use CONST marker in 'translations' and
  3261 @{const_syntax} antiquotation in 'parse_translation' etc.
  3262 
  3263 * Legacy goal package: reduced interface to the bare minimum required
  3264 to keep existing proof scripts running.  Most other user-level
  3265 functions are now part of the OldGoals structure, which is *not* open
  3266 by default (consider isatool expandshort before open OldGoals).
  3267 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3268 these tend to cause confusion about the actual goal (!) context being
  3269 used here, which is not necessarily the same as the_context().
  3270 
  3271 * Command 'find_theorems': supports "*" wild-card in "name:"
  3272 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3273 support a specific search form (see ProofGeneral/CHANGES).
  3274 
  3275 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3276 by default, which means that "prems" (and also "fixed variables") are
  3277 suppressed from proof state output.  Note that the ProofGeneral
  3278 settings mechanism allows to change and save options persistently, but
  3279 older versions of Isabelle will fail to start up if a negative prems
  3280 limit is imposed.
  3281 
  3282 * Local theory targets may be specified by non-nested blocks of
  3283 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3284 contain definitions, theorems etc., including any derived mechanism
  3285 that has been implemented on top of these primitives.  This concept
  3286 generalizes the existing ``theorem (in ...)'' towards more versatility
  3287 and scalability.
  3288 
  3289 * Proof General interface: proper undo of final 'end' command;
  3290 discontinued Isabelle/classic mode (ML proof scripts).
  3291 
  3292 
  3293 *** Document preparation ***
  3294 
  3295 * Added antiquotation @{theory name} which prints the given name,
  3296 after checking that it refers to a valid ancestor theory in the
  3297 current context.
  3298 
  3299 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3300 check the given source text as ML type/structure, printing verbatim.
  3301 
  3302 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3303 "c args == rhs" given in the current context.  (Any number of
  3304 arguments may be given on the LHS.)
  3305 
  3306 
  3307 *** Pure ***
  3308 
  3309 * The 'class' package offers a combination of axclass and locale to
  3310 achieve Haskell-like type classes in Isabelle.  Definitions and
  3311 theorems within a class context produce both relative results (with
  3312 implicit parameters according to the locale context), and polymorphic
  3313 constants with qualified polymorphism (according to the class
  3314 context).  Within the body context of a 'class' target, a separate
  3315 syntax layer ("user space type system") takes care of converting
  3316 between global polymorphic consts and internal locale representation.
  3317 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3318 "isatool doc classes" provides a tutorial.
  3319 
  3320 * Generic code generator framework allows to generate executable
  3321 code for ML and Haskell (including Isabelle classes).  A short usage
  3322 sketch:
  3323 
  3324     internal compilation:
  3325         export_code <list of constants (term syntax)> in SML
  3326     writing SML code to a file:
  3327         export_code <list of constants (term syntax)> in SML <filename>
  3328     writing OCaml code to a file:
  3329         export_code <list of constants (term syntax)> in OCaml <filename>
  3330     writing Haskell code to a bunch of files:
  3331         export_code <list of constants (term syntax)> in Haskell <filename>
  3332 
  3333     evaluating closed propositions to True/False using code generation:
  3334         method ``eval''
  3335 
  3336 Reasonable default setup of framework in HOL.
  3337 
  3338 Theorem attributs for selecting and transforming function equations theorems:
  3339 
  3340     [code fun]:        select a theorem as function equation for a specific constant
  3341     [code fun del]:    deselect a theorem as function equation for a specific constant
  3342     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3343     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3344 
  3345 User-defined serializations (target in {SML, OCaml, Haskell}):
  3346 
  3347     code_const <and-list of constants (term syntax)>
  3348       {(target) <and-list of const target syntax>}+
  3349 
  3350     code_type <and-list of type constructors>
  3351       {(target) <and-list of type target syntax>}+
  3352 
  3353     code_instance <and-list of instances>
  3354       {(target)}+
  3355         where instance ::= <type constructor> :: <class>
  3356 
  3357     code_class <and_list of classes>
  3358       {(target) <and-list of class target syntax>}+
  3359         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3360 
  3361 code_instance and code_class only are effective to target Haskell.
  3362 
  3363 For example usage see src/HOL/ex/Codegenerator.thy and
  3364 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3365 generation from Isabelle/HOL theories is available via "isatool doc
  3366 codegen".
  3367 
  3368 * Code generator: consts in 'consts_code' Isar commands are now
  3369 referred to by usual term syntax (including optional type
  3370 annotations).
  3371 
  3372 * Command 'no_translations' removes translation rules from theory
  3373 syntax.
  3374 
  3375 * Overloaded definitions are now actually checked for acyclic
  3376 dependencies.  The overloading scheme is slightly more general than
  3377 that of Haskell98, although Isabelle does not demand an exact
  3378 correspondence to type class and instance declarations.
  3379 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3380 exotic versions of overloading -- at the discretion of the user!
  3381 
  3382 Polymorphic constants are represented via type arguments, i.e. the
  3383 instantiation that matches an instance against the most general
  3384 declaration given in the signature.  For example, with the declaration
  3385 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3386 as c(nat).  Overloading is essentially simultaneous structural
  3387 recursion over such type arguments.  Incomplete specification patterns
  3388 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3389 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3390 Command 'print_theory' outputs the normalized system of recursive
  3391 equations, see section "definitions".
  3392 
  3393 * Configuration options are maintained within the theory or proof
  3394 context (with name and type bool/int/string), providing a very simple
  3395 interface to a poor-man's version of general context data.  Tools may
  3396 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3397 these values using Config.get etc.  Users may change options via an
  3398 associated attribute of the same name.  This form of context
  3399 declaration works particularly well with commands 'declare' or
  3400 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3401 very easy to avoid global references, which would not observe Isar
  3402 toplevel undo/redo and fail to work with multithreading.
  3403 
  3404 Various global ML references of Pure and HOL have been turned into
  3405 configuration options:
  3406 
  3407   Unify.search_bound		unify_search_bound
  3408   Unify.trace_bound		unify_trace_bound
  3409   Unify.trace_simp		unify_trace_simp
  3410   Unify.trace_types		unify_trace_types
  3411   Simplifier.simp_depth_limit	simp_depth_limit
  3412   Blast.depth_limit		blast_depth_limit
  3413   DatatypeProp.dtK		datatype_distinctness_limit
  3414   fast_arith_neq_limit  	fast_arith_neq_limit
  3415   fast_arith_split_limit	fast_arith_split_limit
  3416 
  3417 * Named collections of theorems may be easily installed as context
  3418 data using the functor NamedThmsFun (see also
  3419 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3420 attributes; there is also a toplevel print command.  This facility is
  3421 just a common case of general context data, which is the preferred way
  3422 for anything more complex than just a list of facts in canonical
  3423 order.
  3424 
  3425 * Isar: command 'declaration' augments a local theory by generic
  3426 declaration functions written in ML.  This enables arbitrary content
  3427 being added to the context, depending on a morphism that tells the
  3428 difference of the original declaration context wrt. the application
  3429 context encountered later on.
  3430 
  3431 * Isar: proper interfaces for simplification procedures.  Command
  3432 'simproc_setup' declares named simprocs (with match patterns, and body
  3433 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3434 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3435 
  3436 * Isar: an extra pair of brackets around attribute declarations
  3437 abbreviates a theorem reference involving an internal dummy fact,
  3438 which will be ignored later --- only the effect of the attribute on
  3439 the background context will persist.  This form of in-place
  3440 declarations is particularly useful with commands like 'declare' and
  3441 'using', for example ``have A using [[simproc a]] by simp''.
  3442 
  3443 * Isar: method "assumption" (and implicit closing of subproofs) now
  3444 takes simple non-atomic goal assumptions into account: after applying
  3445 an assumption as a rule the resulting subgoals are solved by atomic
  3446 assumption steps.  This is particularly useful to finish 'obtain'
  3447 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3448 without referring to the original premise "!!x. P x ==> thesis" in the
  3449 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3450 more permissive.
  3451 
  3452 * Isar: implicit use of prems from the Isar proof context is
  3453 considered a legacy feature.  Common applications like ``have A .''
  3454 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3455 referencing facts explicitly here improves readability and
  3456 maintainability of proof texts.
  3457 
  3458 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3459 the obtained context from the course of reasoning!  For example:
  3460 
  3461   assume "EX x y. A x & B y"   -- "any previous fact"
  3462   then guess x and y by clarify
  3463 
  3464 This technique is potentially adventurous, depending on the facts and
  3465 proof tools being involved here.
  3466 
  3467 * Isar: known facts from the proof context may be specified as literal
  3468 propositions, using ASCII back-quote syntax.  This works wherever
  3469 named facts used to be allowed so far, in proof commands, proof
  3470 methods, attributes etc.  Literal facts are retrieved from the context
  3471 according to unification of type and term parameters.  For example,
  3472 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3473 theorems in the current context, then these are valid literal facts:
  3474 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3475 
  3476 There is also a proof method "fact" which does the same composition
  3477 for explicit goal states, e.g. the following proof texts coincide with
  3478 certain special cases of literal facts:
  3479 
  3480   have "A" by fact                 ==  note `A`
  3481   have "A ==> B" by fact           ==  note `A ==> B`
  3482   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3483   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3484 
  3485 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3486 outer syntax.  Thus symbolic identifiers may be used without
  3487 additional white space in declarations like this: ``assume *: A''.
  3488 
  3489 * Isar: 'print_facts' prints all local facts of the current context,
  3490 both named and unnamed ones.
  3491 
  3492 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3493 
  3494   def x == "t" and y == "u"
  3495 
  3496 * Isar: added command 'unfolding', which is structurally similar to
  3497 'using', but affects both the goal state and facts by unfolding given
  3498 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3499 'unfolded' attribute may be replaced by first-class proof text.
  3500 
  3501 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3502 and command 'unfolding' now all support object-level equalities
  3503 (potentially conditional).  The underlying notion of rewrite rule is
  3504 analogous to the 'rule_format' attribute, but *not* that of the
  3505 Simplifier (which is usually more generous).
  3506 
  3507 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3508 premises of a theorem by n. Useful in conjunction with drule.
  3509 
  3510 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3511 method expression within a sandbox consisting of the first N
  3512 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3513 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3514 simplifies all new goals that emerge from applying rule foo to the
  3515 originally first one.
  3516 
  3517 * Isar: schematic goals are no longer restricted to higher-order
  3518 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3519 expected.
  3520 
  3521 * Isar: the conclusion of a long theorem statement is now either
  3522 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3523 (essentially a disjunction of cases with local parameters and
  3524 assumptions).  The latter allows to express general elimination rules
  3525 adequately; in this notation common elimination rules look like this:
  3526 
  3527   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3528     assumes "EX x. P x"
  3529     obtains x where "P x"
  3530 
  3531   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3532     assumes "A & B"
  3533     obtains A and B
  3534 
  3535   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3536     assumes "A | B"
  3537     obtains
  3538       A
  3539     | B
  3540 
  3541 The subsequent classical rules even refer to the formal "thesis"
  3542 explicitly:
  3543 
  3544   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3545     obtains "~ thesis"
  3546 
  3547   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3548     obtains "thesis ==> something"
  3549 
  3550 The actual proof of an 'obtains' statement is analogous to that of the
  3551 Isar proof element 'obtain', only that there may be several cases.
  3552 Optional case names may be specified in parentheses; these will be
  3553 available both in the present proof and as annotations in the
  3554 resulting rule, for later use with the 'cases' method (cf. attribute
  3555 case_names).
  3556 
  3557 * Isar: the assumptions of a long theorem statement are available as
  3558 "assms" fact in the proof context.  This is more appropriate than the
  3559 (historical) "prems", which refers to all assumptions of the current
  3560 context, including those from the target locale, proof body etc.
  3561 
  3562 * Isar: 'print_statement' prints theorems from the current theory or
  3563 proof context in long statement form, according to the syntax of a
  3564 top-level lemma.
  3565 
  3566 * Isar: 'obtain' takes an optional case name for the local context
  3567 introduction rule (default "that").
  3568 
  3569 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3570 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3571 to occur.
  3572 
  3573 * Pure: syntax "CONST name" produces a fully internalized constant
  3574 according to the current context.  This is particularly useful for
  3575 syntax translations that should refer to internal constant
  3576 representations independently of name spaces.
  3577 
  3578 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3579 instead of "FOO ". This allows multiple binder declarations to coexist
  3580 in the same context.  INCOMPATIBILITY.
  3581 
  3582 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3583 primitive that also works in a locale context (both for constants and
  3584 fixed variables). Type declaration and internal syntactic representation
  3585 of given constants retrieved from the context. Likewise, the
  3586 'no_notation' command allows to remove given syntax annotations from the
  3587 current context.
  3588 
  3589 * Isar/locales: new derived specification elements 'axiomatization',
  3590 'definition', 'abbreviation', which support type-inference, admit
  3591 object-level specifications (equality, equivalence).  See also the
  3592 isar-ref manual.  Examples:
  3593 
  3594   axiomatization
  3595     eq  (infix "===" 50) where
  3596     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3597 
  3598   definition "f x y = x + y + 1"
  3599   definition g where "g x = f x x"
  3600 
  3601   abbreviation
  3602     neq  (infix "=!=" 50) where
  3603     "x =!= y == ~ (x === y)"
  3604 
  3605 These specifications may be also used in a locale context.  Then the
  3606 constants being introduced depend on certain fixed parameters, and the
  3607 constant name is qualified by the locale base name.  An internal
  3608 abbreviation takes care for convenient input and output, making the
  3609 parameters implicit and using the original short name.  See also
  3610 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3611 entities from a monomorphic theory.
  3612 
  3613 Presently, abbreviations are only available 'in' a target locale, but
  3614 not inherited by general import expressions.  Also note that
  3615 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3616 'translations' in common applications.  The "no_abbrevs" print mode
  3617 prevents folding of abbreviations in term output.
  3618 
  3619 Concrete syntax is attached to specified constants in internal form,
  3620 independently of name spaces.  The parse tree representation is
  3621 slightly different -- use 'notation' instead of raw 'syntax', and
  3622 'translations' with explicit "CONST" markup to accommodate this.
  3623 
  3624 * Pure/Isar: unified syntax for new-style specification mechanisms
  3625 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3626 full type inference and dummy patterns ("_").  For example:
  3627 
  3628   definition "K x _ = x"
  3629 
  3630   inductive conj for A B
  3631   where "A ==> B ==> conj A B"
  3632 
  3633 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3634 the current context.  Print mode "no_abbrevs" prevents inversion of
  3635 abbreviations on output.
  3636 
  3637 * Isar/locales: improved parameter handling: use of locales "var" and
  3638 "struct" no longer necessary; - parameter renamings are no longer
  3639 required to be injective.  For example, this allows to define
  3640 endomorphisms as locale endom = homom mult mult h.
  3641 
  3642 * Isar/locales: changed the way locales with predicates are defined.
  3643 Instead of accumulating the specification, the imported expression is
  3644 now an interpretation.  INCOMPATIBILITY: different normal form of
  3645 locale expressions.  In particular, in interpretations of locales with
  3646 predicates, goals repesenting already interpreted fragments are not
  3647 removed automatically.  Use methods `intro_locales' and
  3648 `unfold_locales'; see below.
  3649 
  3650 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3651 provide backward reasoning on locales predicates.  The methods are
  3652 aware of interpretations and discharge corresponding goals.
  3653 `intro_locales' is less aggressive then `unfold_locales' and does not
  3654 unfold predicates to assumptions.
  3655 
  3656 * Isar/locales: the order in which locale fragments are accumulated
  3657 has changed.  This enables to override declarations from fragments due
  3658 to interpretations -- for example, unwanted simp rules.
  3659 
  3660 * Isar/locales: interpretation in theories and proof contexts has been
  3661 extended.  One may now specify (and prove) equations, which are
  3662 unfolded in interpreted theorems.  This is useful for replacing
  3663 defined concepts (constants depending on locale parameters) by
  3664 concepts already existing in the target context.  Example:
  3665 
  3666   interpretation partial_order ["op <= :: [int, int] => bool"]
  3667     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3668 
  3669 Typically, the constant `partial_order.less' is created by a
  3670 definition specification element in the context of locale
  3671 partial_order.
  3672 
  3673 * Method "induct": improved internal context management to support
  3674 local fixes and defines on-the-fly. Thus explicit meta-level
  3675 connectives !!  and ==> are rarely required anymore in inductive goals
  3676 (using object-logic connectives for this purpose has been long
  3677 obsolete anyway). Common proof patterns are explained in
  3678 src/HOL/Induct/Common_Patterns.thy, see also
  3679 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3680 examples.
  3681 
  3682 * Method "induct": improved handling of simultaneous goals. Instead of
  3683 introducing object-level conjunction, the statement is now split into
  3684 several conclusions, while the corresponding symbolic cases are nested
  3685 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3686 see src/HOL/Induct/Common_Patterns.thy, for example.
  3687 
  3688 * Method "induct": mutual induction rules are now specified as a list
  3689 of rule sharing the same induction cases. HOL packages usually provide
  3690 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3691 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3692 mutual induction rules differently, i.e. like this:
  3693 
  3694   (induct rule: foo_bar.inducts)
  3695   (induct set: foo bar)
  3696   (induct pred: foo bar)
  3697   (induct type: foo bar)
  3698 
  3699 The ML function ProjectRule.projections turns old-style rules into the
  3700 new format.
  3701 
  3702 * Method "coinduct": dual of induction, see
  3703 src/HOL/Library/Coinductive_List.thy for various examples.
  3704 
  3705 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3706 considered a legacy feature.
  3707 
  3708 * Attribute "symmetric" produces result with standardized schematic
  3709 variables (index 0).  Potential INCOMPATIBILITY.
  3710 
  3711 * Simplifier: by default the simplifier trace only shows top level
  3712 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3713 default. Thus there is less danger of being flooded by the trace. The
  3714 trace indicates where parts have been suppressed.
  3715   
  3716 * Provers/classical: removed obsolete classical version of elim_format
  3717 attribute; classical elim/dest rules are now treated uniformly when
  3718 manipulating the claset.
  3719 
  3720 * Provers/classical: stricter checks to ensure that supplied intro,
  3721 dest and elim rules are well-formed; dest and elim rules must have at
  3722 least one premise.
  3723 
  3724 * Provers/classical: attributes dest/elim/intro take an optional
  3725 weight argument for the rule (just as the Pure versions).  Weights are
  3726 ignored by automated tools, but determine the search order of single
  3727 rule steps.
  3728 
  3729 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3730 where the body does not mention the bound variable.  Note that dummy
  3731 patterns implicitly depend on their context of bounds, which makes
  3732 "{_. _}" match any set comprehension as expected.  Potential
  3733 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3734 constant "_idtdummy" in the binding position.
  3735 
  3736 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3737 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3738 for example "A -> B" => "Pi A (%_. B)".
  3739 
  3740 * Pure: 'class_deps' command visualizes the subclass relation, using
  3741 the graph browser tool.
  3742 
  3743 * Pure: 'print_theory' now suppresses certain internal declarations by
  3744 default; use '!' option for full details.
  3745 
  3746 
  3747 *** HOL ***
  3748 
  3749 * Method "metis" proves goals by applying the Metis general-purpose
  3750 resolution prover (see also http://gilith.com/software/metis/).
  3751 Examples are in the directory MetisExamples.  WARNING: the
  3752 Isabelle/HOL-Metis integration does not yet work properly with
  3753 multi-threading.
  3754   
  3755 * Command 'sledgehammer' invokes external automatic theorem provers as
  3756 background processes.  It generates calls to the "metis" method if
  3757 successful. These can be pasted into the proof.  Users do not have to
  3758 wait for the automatic provers to return.  WARNING: does not really
  3759 work with multi-threading.
  3760 
  3761 * New "auto_quickcheck" feature tests outermost goal statements for
  3762 potential counter-examples.  Controlled by ML references
  3763 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3764 5000 milliseconds).  Fails silently if statements is outside of
  3765 executable fragment, or any other codgenerator problem occurs.
  3766 
  3767 * New constant "undefined" with axiom "undefined x = undefined".
  3768 
  3769 * Added class "HOL.eq", allowing for code generation with polymorphic
  3770 equality.
  3771 
  3772 * Some renaming of class constants due to canonical name prefixing in
  3773 the new 'class' package:
  3774 
  3775     HOL.abs ~> HOL.abs_class.abs
  3776     HOL.divide ~> HOL.divide_class.divide
  3777     0 ~> HOL.zero_class.zero
  3778     1 ~> HOL.one_class.one
  3779     op + ~> HOL.plus_class.plus
  3780     op - ~> HOL.minus_class.minus
  3781     uminus ~> HOL.minus_class.uminus
  3782     op * ~> HOL.times_class.times
  3783     op < ~> HOL.ord_class.less
  3784     op <= > HOL.ord_class.less_eq
  3785     Nat.power ~> Power.power_class.power
  3786     Nat.size ~> Nat.size_class.size
  3787     Numeral.number_of ~> Numeral.number_class.number_of
  3788     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3789     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3790     Orderings.min ~> Orderings.ord_class.min
  3791     Orderings.max ~> Orderings.ord_class.max
  3792     Divides.op div ~> Divides.div_class.div
  3793     Divides.op mod ~> Divides.div_class.mod
  3794     Divides.op dvd ~> Divides.div_class.dvd
  3795 
  3796 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3797 
  3798 a) User-defined constants using any of the names "plus", "minus",
  3799 "times", "less" or "less_eq". The standard syntax translations for
  3800 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3801 names.
  3802 
  3803 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3804 INCOMPATIBILITY: use more specific names.
  3805 
  3806 c) Permutative equations (e.g. "a + b = b + a")
  3807 Since the change of names also changes the order of terms, permutative
  3808 rewrite rules may get applied in a different order. Experience shows
  3809 that this is rarely the case (only two adaptions in the whole Isabelle
  3810 distribution).  INCOMPATIBILITY: rewrite proofs
  3811 
  3812 d) ML code directly refering to constant names
  3813 This in general only affects hand-written proof tactics, simprocs and
  3814 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3815 Consider using @{const_name} antiquotation.
  3816 
  3817 * New class "default" with associated constant "default".
  3818 
  3819 * Function "sgn" is now overloaded and available on int, real, complex
  3820 (and other numeric types), using class "sgn".  Two possible defs of
  3821 sgn are given as equational assumptions in the classes sgn_if and
  3822 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3823 INCOMPATIBILITY.
  3824 
  3825 * Locale "partial_order" now unified with class "order" (cf. theory
  3826 Orderings), added parameter "less".  INCOMPATIBILITY.
  3827 
  3828 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3829 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3830 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3831 
  3832 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3833 changed order of proof goals in instance proofs.
  3834 
  3835 * The transitivity reasoner for partial and linear orders is set up
  3836 for classes "order" and "linorder".  Instances of the reasoner are available
  3837 in all contexts importing or interpreting the corresponding locales.
  3838 Method "order" invokes the reasoner separately; the reasoner
  3839 is also integrated with the Simplifier as a solver.  Diagnostic
  3840 command 'print_orders' shows the available instances of the reasoner
  3841 in the current context.
  3842 
  3843 * Localized monotonicity predicate in theory "Orderings"; integrated
  3844 lemmas max_of_mono and min_of_mono with this predicate.
  3845 INCOMPATIBILITY.
  3846 
  3847 * Formulation of theorem "dense" changed slightly due to integration
  3848 with new class dense_linear_order.
  3849 
  3850 * Uniform lattice theory development in HOL.
  3851 
  3852     constants "meet" and "join" now named "inf" and "sup"
  3853     constant "Meet" now named "Inf"
  3854 
  3855     classes "meet_semilorder" and "join_semilorder" now named
  3856       "lower_semilattice" and "upper_semilattice"
  3857     class "lorder" now named "lattice"
  3858     class "comp_lat" now named "complete_lattice"
  3859 
  3860     Instantiation of lattice classes allows explicit definitions
  3861     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3862 
  3863   INCOMPATIBILITY.  Theorem renames:
  3864 
  3865     meet_left_le            ~> inf_le1
  3866     meet_right_le           ~> inf_le2
  3867     join_left_le            ~> sup_ge1
  3868     join_right_le           ~> sup_ge2
  3869     meet_join_le            ~> inf_sup_ord
  3870     le_meetI                ~> le_infI
  3871     join_leI                ~> le_supI
  3872     le_meet                 ~> le_inf_iff
  3873     le_join                 ~> ge_sup_conv
  3874     meet_idempotent         ~> inf_idem
  3875     join_idempotent         ~> sup_idem
  3876     meet_comm               ~> inf_commute
  3877     join_comm               ~> sup_commute
  3878     meet_leI1               ~> le_infI1
  3879     meet_leI2               ~> le_infI2
  3880     le_joinI1               ~> le_supI1
  3881     le_joinI2               ~> le_supI2
  3882     meet_assoc              ~> inf_assoc
  3883     join_assoc              ~> sup_assoc
  3884     meet_left_comm          ~> inf_left_commute
  3885     meet_left_idempotent    ~> inf_left_idem
  3886     join_left_comm          ~> sup_left_commute
  3887     join_left_idempotent    ~> sup_left_idem
  3888     meet_aci                ~> inf_aci
  3889     join_aci                ~> sup_aci
  3890     le_def_meet             ~> le_iff_inf
  3891     le_def_join             ~> le_iff_sup
  3892     join_absorp2            ~> sup_absorb2
  3893     join_absorp1            ~> sup_absorb1
  3894     meet_absorp1            ~> inf_absorb1
  3895     meet_absorp2            ~> inf_absorb2
  3896     meet_join_absorp        ~> inf_sup_absorb
  3897     join_meet_absorp        ~> sup_inf_absorb
  3898     distrib_join_le         ~> distrib_sup_le
  3899     distrib_meet_le         ~> distrib_inf_le
  3900 
  3901     add_meet_distrib_left   ~> add_inf_distrib_left
  3902     add_join_distrib_left   ~> add_sup_distrib_left
  3903     is_join_neg_meet        ~> is_join_neg_inf
  3904     is_meet_neg_join        ~> is_meet_neg_sup
  3905     add_meet_distrib_right  ~> add_inf_distrib_right
  3906     add_join_distrib_right  ~> add_sup_distrib_right
  3907     add_meet_join_distribs  ~> add_sup_inf_distribs
  3908     join_eq_neg_meet        ~> sup_eq_neg_inf
  3909     meet_eq_neg_join        ~> inf_eq_neg_sup
  3910     add_eq_meet_join        ~> add_eq_inf_sup
  3911     meet_0_imp_0            ~> inf_0_imp_0
  3912     join_0_imp_0            ~> sup_0_imp_0
  3913     meet_0_eq_0             ~> inf_0_eq_0
  3914     join_0_eq_0             ~> sup_0_eq_0
  3915     neg_meet_eq_join        ~> neg_inf_eq_sup
  3916     neg_join_eq_meet        ~> neg_sup_eq_inf
  3917     join_eq_if              ~> sup_eq_if
  3918 
  3919     mono_meet               ~> mono_inf
  3920     mono_join               ~> mono_sup
  3921     meet_bool_eq            ~> inf_bool_eq
  3922     join_bool_eq            ~> sup_bool_eq
  3923     meet_fun_eq             ~> inf_fun_eq
  3924     join_fun_eq             ~> sup_fun_eq
  3925     meet_set_eq             ~> inf_set_eq
  3926     join_set_eq             ~> sup_set_eq
  3927     meet1_iff               ~> inf1_iff
  3928     meet2_iff               ~> inf2_iff
  3929     meet1I                  ~> inf1I
  3930     meet2I                  ~> inf2I
  3931     meet1D1                 ~> inf1D1
  3932     meet2D1                 ~> inf2D1
  3933     meet1D2                 ~> inf1D2
  3934     meet2D2                 ~> inf2D2
  3935     meet1E                  ~> inf1E
  3936     meet2E                  ~> inf2E
  3937     join1_iff               ~> sup1_iff
  3938     join2_iff               ~> sup2_iff
  3939     join1I1                 ~> sup1I1
  3940     join2I1                 ~> sup2I1
  3941     join1I1                 ~> sup1I1
  3942     join2I2                 ~> sup1I2
  3943     join1CI                 ~> sup1CI
  3944     join2CI                 ~> sup2CI
  3945     join1E                  ~> sup1E
  3946     join2E                  ~> sup2E
  3947 
  3948     is_meet_Meet            ~> is_meet_Inf
  3949     Meet_bool_def           ~> Inf_bool_def
  3950     Meet_fun_def            ~> Inf_fun_def
  3951     Meet_greatest           ~> Inf_greatest
  3952     Meet_lower              ~> Inf_lower
  3953     Meet_set_def            ~> Inf_set_def
  3954 
  3955     Sup_def                 ~> Sup_Inf
  3956     Sup_bool_eq             ~> Sup_bool_def
  3957     Sup_fun_eq              ~> Sup_fun_def
  3958     Sup_set_eq              ~> Sup_set_def
  3959 
  3960     listsp_meetI            ~> listsp_infI
  3961     listsp_meet_eq          ~> listsp_inf_eq
  3962 
  3963     meet_min                ~> inf_min
  3964     join_max                ~> sup_max
  3965 
  3966 * Added syntactic class "size"; overloaded constant "size" now has
  3967 type "'a::size ==> bool"
  3968 
  3969 * Internal reorganisation of `size' of datatypes: size theorems
  3970 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3971 simplification rules by default!); theorems "prod.size" now named
  3972 "*.size".
  3973 
  3974 * Class "div" now inherits from class "times" rather than "type".
  3975 INCOMPATIBILITY.
  3976 
  3977 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3978 Linorder etc.  have disappeared; operations defined in terms of
  3979 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3980 
  3981 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3982 
  3983 * HOL-Word: New extensive library and type for generic, fixed size
  3984 machine words, with arithemtic, bit-wise, shifting and rotating
  3985 operations, reflection into int, nat, and bool lists, automation for
  3986 linear arithmetic (by automatic reflection into nat or int), including
  3987 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3988 arithmetic type classes, supporting automatic simplification of
  3989 numerals on all operations.
  3990 
  3991 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3992 
  3993 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3994 
  3995 * Code generator library theories:
  3996   - Code_Integer represents HOL integers by big integer literals in target
  3997     languages.
  3998   - Code_Char represents HOL characters by character literals in target
  3999     languages.
  4000   - Code_Char_chr like Code_Char, but also offers treatment of character
  4001     codes; includes Code_Integer.
  4002   - Executable_Set allows to generate code for finite sets using lists.
  4003   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4004     denominator).
  4005   - Executable_Real implements a subset of real numbers, namly those
  4006     representable by rational numbers.
  4007   - Efficient_Nat implements natural numbers by integers, which in general will
  4008     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4009     includes Code_Integer.
  4010   - Code_Index provides an additional datatype index which is mapped to
  4011     target-language built-in integers.
  4012   - Code_Message provides an additional datatype message_string which is isomorphic to
  4013     strings; messages are mapped to target-language strings.
  4014 
  4015 * New package for inductive predicates
  4016 
  4017   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4018 
  4019     inductive
  4020       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4021       for z_1 :: U_1 and ... and z_n :: U_m
  4022     where
  4023       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4024     | ...
  4025 
  4026   with full support for type-inference, rather than
  4027 
  4028     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4029 
  4030     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4031     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4032 
  4033     inductive "s z_1 ... z_m"
  4034     intros
  4035       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4036       ...
  4037 
  4038   For backward compatibility, there is a wrapper allowing inductive
  4039   sets to be defined with the new package via
  4040 
  4041     inductive_set
  4042       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4043       for z_1 :: U_1 and ... and z_n :: U_m
  4044     where
  4045       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4046     | ...
  4047 
  4048   or
  4049 
  4050     inductive_set
  4051       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4052       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4053       for z_1 :: U_1 and ... and z_n :: U_m
  4054     where
  4055       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4056     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4057     | ...
  4058 
  4059   if the additional syntax "p ..." is required.
  4060 
  4061   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4062   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4063 
  4064   INCOMPATIBILITIES:
  4065 
  4066   - Since declaration and definition of inductive sets or predicates
  4067     is no longer separated, abbreviations involving the newly
  4068     introduced sets or predicates must be specified together with the
  4069     introduction rules after the 'where' keyword (see above), rather
  4070     than before the actual inductive definition.
  4071 
  4072   - The variables in induction and elimination rules are now
  4073     quantified in the order of their occurrence in the introduction
  4074     rules, rather than in alphabetical order. Since this may break
  4075     some proofs, these proofs either have to be repaired, e.g. by
  4076     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4077     statements of the form
  4078 
  4079       case (rule_i a_i_1 ... a_i_{k_i})
  4080 
  4081     or the old order of quantification has to be restored by explicitly adding
  4082     meta-level quantifiers in the introduction rules, i.e.
  4083 
  4084       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4085 
  4086   - The format of the elimination rules is now
  4087 
  4088       p z_1 ... z_m x_1 ... x_n ==>
  4089         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4090         ==> ... ==> P
  4091 
  4092     for predicates and
  4093 
  4094       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4095         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4096         ==> ... ==> P
  4097 
  4098     for sets rather than
  4099 
  4100       x : s z_1 ... z_m ==>
  4101         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4102         ==> ... ==> P
  4103 
  4104     This may require terms in goals to be expanded to n-tuples
  4105     (e.g. using case_tac or simplification with the split_paired_all
  4106     rule) before the above elimination rule is applicable.
  4107 
  4108   - The elimination or case analysis rules for (mutually) inductive
  4109     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4110     list of rules "p_1_..._p_k.elims" is no longer available.
  4111 
  4112 * New package "function"/"fun" for general recursive functions,
  4113 supporting mutual and nested recursion, definitions in local contexts,
  4114 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4115 for small examples, and the separate tutorial on the function
  4116 package. The old recdef "package" is still available as before, but
  4117 users are encouraged to use the new package.
  4118 
  4119 * Method "lexicographic_order" automatically synthesizes termination
  4120 relations as lexicographic combinations of size measures. 
  4121 
  4122 * Case-expressions allow arbitrary constructor-patterns (including
  4123 "_") and take their order into account, like in functional
  4124 programming.  Internally, this is translated into nested
  4125 case-expressions; missing cases are added and mapped to the predefined
  4126 constant "undefined". In complicated cases printing may no longer show
  4127 the original input but the internal form. Lambda-abstractions allow
  4128 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4129 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4130 variable.
  4131 
  4132 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4133 is an abbreviation for "of_nat :: nat => int". The simplification
  4134 rules for "of_nat" have been changed to work like "int" did
  4135 previously.  Potential INCOMPATIBILITY:
  4136   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4137   - of_nat_diff and of_nat_mult are no longer default simp rules
  4138 
  4139 * Method "algebra" solves polynomial equations over (semi)rings using
  4140 Groebner bases. The (semi)ring structure is defined by locales and the
  4141 tool setup depends on that generic context. Installing the method for
  4142 a specific type involves instantiating the locale and possibly adding
  4143 declarations for computation on the coefficients.  The method is
  4144 already instantiated for natural numbers and for the axiomatic class
  4145 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4146 CALCULEMUS 2007 for the general principles underlying this
  4147 architecture of context-aware proof-tools.
  4148 
  4149 * Method "ferrack" implements quantifier elimination over
  4150 special-purpose dense linear orders using locales (analogous to
  4151 "algebra"). The method is already installed for class
  4152 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4153 rat, etc.
  4154 
  4155 * Former constant "List.op @" now named "List.append".  Use ML
  4156 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4157 circumvent possible incompatibilities when working on ML level.
  4158 
  4159 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4160 
  4161 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4162 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4163 
  4164 * New syntax for Haskell-like list comprehension (input only), eg.
  4165 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4166 
  4167 * The special syntax for function "filter" has changed from [x :
  4168 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4169 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4170 
  4171 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4172 defined on nat only, as an abbreviation for [a..<Suc b]
  4173 INCOMPATIBILITY.
  4174 
  4175 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4176 
  4177 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4178 
  4179 * New lemma collection field_simps (an extension of ring_simps) for
  4180 manipulating (in)equations involving division. Multiplies with all
  4181 denominators that can be proved to be non-zero (in equations) or
  4182 positive/negative (in inequations).
  4183 
  4184 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4185 have been improved and renamed to ring_simps, group_simps and
  4186 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4187 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4188 
  4189 * Theory Library/Commutative_Ring: switched from recdef to function
  4190 package; constants add, mul, pow now curried.  Infix syntax for
  4191 algebraic operations.
  4192 
  4193 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4194 INCOMPATIBILITY.
  4195 
  4196 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4197 INCOMPATIBILITY.
  4198 
  4199 * HOL/records: generalised field-update to take a function on the
  4200 field rather than the new value: r(|A := x|) is translated to A_update
  4201 (K x) r The K-combinator that is internally used is called K_record.
  4202 INCOMPATIBILITY: Usage of the plain update functions has to be
  4203 adapted.
  4204  
  4205 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4206 * x = 0, which are required for a semiring.  Richer structures do not
  4207 inherit from semiring_0 anymore, because this property is a theorem
  4208 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4209 there is more to prove, but this is mostly trivial.
  4210 
  4211 * Class "recpower" is generalized to arbitrary monoids, not just
  4212 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4213 commutativity or semiring properties additionally.
  4214 
  4215 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4216 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4217 better use 'abbreviation'.
  4218 
  4219 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4220 
  4221 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4222 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4223 significant changes for setting up numeral syntax for types:
  4224   - New constants Numeral.pred and Numeral.succ instead
  4225       of former Numeral.bin_pred and Numeral.bin_succ.
  4226   - Use integer operations instead of bin_add, bin_mult and so on.
  4227   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4228   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4229 
  4230 See src/HOL/Integ/IntArith.thy for an example setup.
  4231 
  4232 * Command 'normal_form' computes the normal form of a term that may
  4233 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4234 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4235 heavy-duty computations because the functions are compiled to ML
  4236 first.  Correspondingly, a method "normalization" is provided.  See
  4237 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4238 
  4239 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4240 25 like -->); output depends on the "iff" print_mode, the default is
  4241 "A = B" (with priority 50).
  4242 
  4243 * Relations less (<) and less_eq (<=) are also available on type bool.
  4244 Modified syntax to disallow nesting without explicit parentheses,
  4245 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4246 INCOMPATIBILITY.
  4247 
  4248 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4249 
  4250 * Relation composition operator "op O" now has precedence 75 and binds
  4251 stronger than union and intersection. INCOMPATIBILITY.
  4252 
  4253 * The old set interval syntax "{m..n(}" (and relatives) has been
  4254 removed.  Use "{m..<n}" (and relatives) instead.
  4255 
  4256 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4257 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4258 ``declare [[simproc del: neq]]''.
  4259 
  4260 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4261 True/False.
  4262 
  4263 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4264 
  4265 * Theorem setsum_mult renamed to setsum_right_distrib.
  4266 
  4267 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4268 ``rule'' method.
  4269 
  4270 * Reimplemented methods "sat" and "satx", with several improvements:
  4271 goals no longer need to be stated as "<prems> ==> False", equivalences
  4272 (i.e. "=" on type bool) are handled, variable names of the form
  4273 "lit_<n>" are no longer reserved, significant speedup.
  4274 
  4275 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4276 zChaff is still supported as well.
  4277 
  4278 * 'inductive' and 'datatype': provide projections of mutual rules,
  4279 bundled as foo_bar.inducts;
  4280 
  4281 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4282 Library.
  4283 
  4284 * Library: moved theory Accessible_Part to main HOL.
  4285 
  4286 * Library: added theory Coinductive_List of potentially infinite lists
  4287 as greatest fixed-point.
  4288 
  4289 * Library: added theory AssocList which implements (finite) maps as
  4290 association lists.
  4291 
  4292 * Method "evaluation" solves goals (i.e. a boolean expression)
  4293 efficiently by compiling it to ML.  The goal is "proved" (via an
  4294 oracle) if it evaluates to True.
  4295 
  4296 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4297 also when invoked by the simplifier.  This results in the Simplifier
  4298 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4299 Configuration option fast_arith_split_limit=0 recovers the old
  4300 behavior.
  4301 
  4302 * Support for hex (0x20) and binary (0b1001) numerals.
  4303 
  4304 * New method: reify eqs (t), where eqs are equations for an
  4305 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4306 parameter, computes a term s::'b and a list xs::'a list and proves the
  4307 theorem I xs s = t. This is also known as reification or quoting. The
  4308 resulting theorem is applied to the subgoal to substitute t with I xs
  4309 s.  If t is omitted, the subgoal itself is reified.
  4310 
  4311 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4312 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4313 where f is supposed to be a computable function (in the sense of code
  4314 generattion). The method uses reify to compute s and xs as above then
  4315 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4316 r and finally gets the theorem t = r, which is again applied to the
  4317 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4318 
  4319 * Reflection: Automatic reification now handels binding, an example is
  4320 available in src/HOL/ex/ReflectionEx.thy
  4321 
  4322 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4323 command 'statespace' that is similar to 'record', but introduces an
  4324 abstract specification based on the locale infrastructure instead of
  4325 HOL types.  This leads to extra flexibility in composing state spaces,
  4326 in particular multiple inheritance and renaming of components.
  4327 
  4328 
  4329 *** HOL-Complex ***
  4330 
  4331 * Hyperreal: Functions root and sqrt are now defined on negative real
  4332 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4333 Nonnegativity side conditions have been removed from many lemmas, so
  4334 that more subgoals may now be solved by simplification; potential
  4335 INCOMPATIBILITY.
  4336 
  4337 * Real: new type classes formalize real normed vector spaces and
  4338 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4339 and norm :: 'a => real.
  4340 
  4341 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4342 reals into other types. The overloaded constant Reals :: 'a set is now
  4343 defined as range of_real; potential INCOMPATIBILITY.
  4344 
  4345 * Real: proper support for ML code generation, including 'quickcheck'.
  4346 Reals are implemented as arbitrary precision rationals.
  4347 
  4348 * Hyperreal: Several constants that previously worked only for the
  4349 reals have been generalized, so they now work over arbitrary vector
  4350 spaces. Type annotations may need to be added in some cases; potential
  4351 INCOMPATIBILITY.
  4352 
  4353   Infinitesimal  :: ('a::real_normed_vector) star set
  4354   HFinite        :: ('a::real_normed_vector) star set
  4355   HInfinite      :: ('a::real_normed_vector) star set
  4356   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4357   monad          :: ('a::real_normed_vector) star => 'a star set
  4358   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4359   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4360   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4361   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4362   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4363   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4364   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4365   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4366   sgn            :: 'a::real_normed_vector => 'a
  4367   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4368 
  4369 * Complex: Some complex-specific constants are now abbreviations for
  4370 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4371 hnorm.  Other constants have been entirely removed in favor of the
  4372 polymorphic versions (INCOMPATIBILITY):
  4373 
  4374   approx        <-- capprox
  4375   HFinite       <-- CFinite
  4376   HInfinite     <-- CInfinite
  4377   Infinitesimal <-- CInfinitesimal
  4378   monad         <-- cmonad
  4379   galaxy        <-- cgalaxy
  4380   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4381   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4382   (ns)deriv     <-- (ns)cderiv
  4383 
  4384 
  4385 *** HOL-Algebra ***
  4386 
  4387 * Formalisation of ideals and the quotient construction over rings.
  4388 
  4389 * Order and lattice theory no longer based on records.
  4390 INCOMPATIBILITY.
  4391 
  4392 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4393 greatest_closed.  INCOMPATIBILITY.
  4394 
  4395 * Method algebra is now set up via an attribute.  For examples see
  4396 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4397 of algebraic structures.
  4398 
  4399 * Renamed theory CRing to Ring.
  4400 
  4401 
  4402 *** HOL-Nominal ***
  4403 
  4404 * Substantial, yet incomplete support for nominal datatypes (binding
  4405 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4406 src/HOL/Nominal/Examples.  Prospective users should consult
  4407 http://isabelle.in.tum.de/nominal/
  4408 
  4409 
  4410 *** ML ***
  4411 
  4412 * ML basics: just one true type int, which coincides with IntInf.int
  4413 (even on SML/NJ).
  4414 
  4415 * ML within Isar: antiquotations allow to embed statically-checked
  4416 formal entities in the source, referring to the context available at
  4417 compile-time.  For example:
  4418 
  4419 ML {* @{sort "{zero,one}"} *}
  4420 ML {* @{typ "'a => 'b"} *}
  4421 ML {* @{term "%x. x"} *}
  4422 ML {* @{prop "x == y"} *}
  4423 ML {* @{ctyp "'a => 'b"} *}
  4424 ML {* @{cterm "%x. x"} *}
  4425 ML {* @{cprop "x == y"} *}
  4426 ML {* @{thm asm_rl} *}
  4427 ML {* @{thms asm_rl} *}
  4428 ML {* @{type_name c} *}
  4429 ML {* @{type_syntax c} *}
  4430 ML {* @{const_name c} *}
  4431 ML {* @{const_syntax c} *}
  4432 ML {* @{context} *}
  4433 ML {* @{theory} *}
  4434 ML {* @{theory Pure} *}
  4435 ML {* @{theory_ref} *}
  4436 ML {* @{theory_ref Pure} *}
  4437 ML {* @{simpset} *}
  4438 ML {* @{claset} *}
  4439 ML {* @{clasimpset} *}
  4440 
  4441 The same works for sources being ``used'' within an Isar context.
  4442 
  4443 * ML in Isar: improved error reporting; extra verbosity with
  4444 ML_Context.trace enabled.
  4445 
  4446 * Pure/General/table.ML: the join operations now works via exceptions
  4447 DUP/SAME instead of type option. This is simpler in simple cases, and
  4448 admits slightly more efficient complex applications.
  4449 
  4450 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4451 use Context.generic instead of just theory.
  4452 
  4453 * Pure: datatype Context.generic joins theory/Proof.context and
  4454 provides some facilities for code that works in either kind of
  4455 context, notably GenericDataFun for uniform theory and proof data.
  4456 
  4457 * Pure: simplified internal attribute type, which is now always
  4458 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4459 local (Proof.context) attributes have been discontinued, while
  4460 minimizing code duplication. Thm.rule_attribute and
  4461 Thm.declaration_attribute build canonical attributes; see also structure
  4462 Context for further operations on Context.generic, notably
  4463 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4464 declarations and definitions.
  4465 
  4466 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4467 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4468 init only required for impure data. INCOMPATIBILITY: empty really need
  4469 to be empty (no dependencies on theory content!)
  4470 
  4471 * Pure/kernel: consts certification ignores sort constraints given in
  4472 signature declarations. (This information is not relevant to the
  4473 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4474 potential INCOMPATIBILITY.
  4475 
  4476 * Pure: axiomatic type classes are now purely definitional, with
  4477 explicit proofs of class axioms and super class relations performed
  4478 internally. See Pure/axclass.ML for the main internal interfaces --
  4479 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4480 AxClass.axiomatize_class/classrel/arity supersede
  4481 Sign.add_classes/classrel/arities.
  4482 
  4483 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4484 global/local versions on theory vs. Proof.context have been
  4485 discontinued; Attrib.syntax and Method.syntax have been adapted
  4486 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4487 attributes, methods, etc.
  4488 
  4489 * Pure: several functions of signature "... -> theory -> theory * ..."
  4490 have been reoriented to "... -> theory -> ... * theory" in order to
  4491 allow natural usage in combination with the ||>, ||>>, |-> and
  4492 fold_map combinators.
  4493 
  4494 * Pure: official theorem names (closed derivations) and additional
  4495 comments (tags) are now strictly separate.  Name hints -- which are
  4496 maintained as tags -- may be attached any time without affecting the
  4497 derivation.
  4498 
  4499 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4500 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4501 achieve the old behaviour.
  4502 
  4503 * Pure: the "Goal" constant is now called "prop", supporting a
  4504 slightly more general idea of ``protecting'' meta-level rule
  4505 statements.
  4506 
  4507 * Pure: Logic.(un)varify only works in a global context, which is now
  4508 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4509 Logic.legacy_(un)varify as temporary workaround.
  4510 
  4511 * Pure: structure Name provides scalable operations for generating
  4512 internal variable names, notably Name.variants etc.  This replaces
  4513 some popular functions from term.ML:
  4514 
  4515   Term.variant		->  Name.variant
  4516   Term.variantlist	->  Name.variant_list
  4517   Term.invent_names	->  Name.invent_list
  4518 
  4519 Note that low-level renaming rarely occurs in new code -- operations
  4520 from structure Variable are used instead (see below).
  4521 
  4522 * Pure: structure Variable provides fundamental operations for proper
  4523 treatment of fixed/schematic variables in a context.  For example,
  4524 Variable.import introduces fixes for schematics of given facts and
  4525 Variable.export reverses the effect (up to renaming) -- this replaces
  4526 various freeze_thaw operations.
  4527 
  4528 * Pure: structure Goal provides simple interfaces for
  4529 init/conclude/finish and tactical prove operations (replacing former
  4530 Tactic.prove).  Goal.prove is the canonical way to prove results
  4531 within a given context; Goal.prove_global is a degraded version for
  4532 theory level goals, including a global Drule.standard.  Note that
  4533 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4534 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4535 in a locale context).
  4536 
  4537 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4538 and type checking (Syntax.check_term etc.), with common combinations
  4539 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4540 which are considered legacy and await removal.
  4541 
  4542 * Pure/Syntax: generic interfaces for type unchecking
  4543 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4544 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4545 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4546 available for convenience, but refer to the very same operations using
  4547 a mere theory instead of a full context.
  4548 
  4549 * Isar: simplified treatment of user-level errors, using exception
  4550 ERROR of string uniformly.  Function error now merely raises ERROR,
  4551 without any side effect on output channels.  The Isar toplevel takes
  4552 care of proper display of ERROR exceptions.  ML code may use plain
  4553 handle/can/try; cat_error may be used to concatenate errors like this:
  4554 
  4555   ... handle ERROR msg => cat_error msg "..."
  4556 
  4557 Toplevel ML code (run directly or through the Isar toplevel) may be
  4558 embedded into the Isar toplevel with exception display/debug like
  4559 this:
  4560 
  4561   Isar.toplevel (fn () => ...)
  4562 
  4563 INCOMPATIBILITY, removed special transform_error facilities, removed
  4564 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4565 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4566 -- use plain ERROR instead.
  4567 
  4568 * Isar: theory setup now has type (theory -> theory), instead of a
  4569 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4570 
  4571 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4572 ProofContext.debug/verbose flags.
  4573 
  4574 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4575 theory before entering a proof state.  Transactions now always see a
  4576 quasi-functional intermediate checkpoint, both in interactive and
  4577 batch mode.
  4578 
  4579 * Isar: simplified interfaces for outer syntax.  Renamed
  4580 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4581 OuterSyntax.add_parsers -- this functionality is now included in
  4582 OuterSyntax.command etc.  INCOMPATIBILITY.
  4583 
  4584 * Simplifier: the simpset of a running simplification process now
  4585 contains a proof context (cf. Simplifier.the_context), which is the
  4586 very context that the initial simpset has been retrieved from (by
  4587 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4588 (solver, looper etc.) may depend on arbitrary proof data.
  4589 
  4590 * Simplifier.inherit_context inherits the proof context (plus the
  4591 local bounds) of the current simplification process; any simproc
  4592 etc. that calls the Simplifier recursively should do this!  Removed
  4593 former Simplifier.inherit_bounds, which is already included here --
  4594 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4595 specify an explicit context using Simplifier.context/theory_context.
  4596 
  4597 * Simplifier/Classical Reasoner: more abstract interfaces
  4598 change_simpset/claset for modifying the simpset/claset reference of a
  4599 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4600 INCOMPATIBILITY.
  4601 
  4602 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4603 "Trueprop" etc.
  4604 
  4605 
  4606 *** System ***
  4607 
  4608 * settings: the default heap location within ISABELLE_HOME_USER now
  4609 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4610 Isabelle installations.
  4611 
  4612 * isabelle-process: option -S (secure mode) disables some critical
  4613 operations, notably runtime compilation and evaluation of ML source
  4614 code.
  4615 
  4616 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4617 
  4618 * Support for parallel execution, using native multicore support of
  4619 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4620 independent theories, according to the given theory header
  4621 specifications. The maximum number of worker threads is specified via
  4622 usedir option -M or the "max-threads" setting in Proof General. A
  4623 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4624 to 6 on a 8-core machine.  User-code needs to observe certain
  4625 guidelines for thread-safe programming, see appendix A in the Isar
  4626 Implementation manual.
  4627 
  4628 
  4629 
  4630 New in Isabelle2005 (October 2005)
  4631 ----------------------------------
  4632 
  4633 *** General ***
  4634 
  4635 * Theory headers: the new header syntax for Isar theories is
  4636 
  4637   theory <name>
  4638   imports <theory1> ... <theoryN>
  4639   uses <file1> ... <fileM>
  4640   begin
  4641 
  4642 where the 'uses' part is optional.  The previous syntax
  4643 
  4644   theory <name> = <theory1> + ... + <theoryN>:
  4645 
  4646 will disappear in the next release.  Use isatool fixheaders to convert
  4647 existing theory files.  Note that there is no change in ancient
  4648 non-Isar theories now, but these will disappear soon.
  4649 
  4650 * Theory loader: parent theories can now also be referred to via
  4651 relative and absolute paths.
  4652 
  4653 * Command 'find_theorems' searches for a list of criteria instead of a
  4654 list of constants. Known criteria are: intro, elim, dest, name:string,
  4655 simp:term, and any term. Criteria can be preceded by '-' to select
  4656 theorems that do not match. Intro, elim, dest select theorems that
  4657 match the current goal, name:s selects theorems whose fully qualified
  4658 name contain s, and simp:term selects all simplification rules whose
  4659 lhs match term.  Any other term is interpreted as pattern and selects
  4660 all theorems matching the pattern. Available in ProofGeneral under
  4661 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4662 
  4663   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4664 
  4665 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4666 matching the current goal as introduction rule and not having "HOL."
  4667 in their name (i.e. not being defined in theory HOL).
  4668 
  4669 * Command 'thms_containing' has been discontinued in favour of
  4670 'find_theorems'; INCOMPATIBILITY.
  4671 
  4672 * Communication with Proof General is now 8bit clean, which means that
  4673 Unicode text in UTF-8 encoding may be used within theory texts (both
  4674 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4675 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4676 
  4677   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4678   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4679 
  4680 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4681 Classical Reasoner.  Typical big applications run around 2 times
  4682 faster.
  4683 
  4684 
  4685 *** Document preparation ***
  4686 
  4687 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4688 of raw sources.  Only those symbols that do not require additional
  4689 LaTeX packages (depending on comments in isabellesym.sty) are
  4690 displayed properly, everything else is left verbatim.  isatool display
  4691 and isatool print are used as front ends (these are subject to the
  4692 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4693 
  4694 * Command tags control specific markup of certain regions of text,
  4695 notably folding and hiding.  Predefined tags include "theory" (for
  4696 theory begin and end), "proof" for proof commands, and "ML" for
  4697 commands involving ML code; the additional tags "visible" and
  4698 "invisible" are unused by default.  Users may give explicit tag
  4699 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4700 interpretation of tags is determined by the LaTeX job during document
  4701 preparation: see option -V of isatool usedir, or options -n and -t of
  4702 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4703 \isadroptag.
  4704 
  4705 Several document versions may be produced at the same time via isatool
  4706 usedir (the generated index.html will link all of them).  Typical
  4707 specifications include ''-V document=theory,proof,ML'' to present
  4708 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4709 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4710 these parts without any formal replacement text.  The Isabelle site
  4711 default settings produce ''document'' and ''outline'' versions as
  4712 specified above.
  4713 
  4714 * Several new antiquotations:
  4715 
  4716   @{term_type term} prints a term with its type annotated;
  4717 
  4718   @{typeof term} prints the type of a term;
  4719 
  4720   @{const const} is the same as @{term const}, but checks that the
  4721   argument is a known logical constant;
  4722 
  4723   @{term_style style term} and @{thm_style style thm} print a term or
  4724   theorem applying a "style" to it
  4725 
  4726   @{ML text}
  4727 
  4728 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4729 definitions, equations, inequations etc., 'concl' printing only the
  4730 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4731 to print the specified premise.  TermStyle.add_style provides an ML
  4732 interface for introducing further styles.  See also the "LaTeX Sugar"
  4733 document practical applications.  The ML antiquotation prints
  4734 type-checked ML expressions verbatim.
  4735 
  4736 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4737 and 'text' support optional locale specification '(in loc)', which
  4738 specifies the default context for interpreting antiquotations.  For
  4739 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4740 
  4741 * Option 'locale=NAME' of antiquotations specifies an alternative
  4742 context interpreting the subsequent argument.  For example: @{thm
  4743 [locale=lattice] inf_assoc}.
  4744 
  4745 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4746 a proof context.
  4747 
  4748 * Proper output of antiquotations for theory commands involving a
  4749 proof context (such as 'locale' or 'theorem (in loc) ...').
  4750 
  4751 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4752 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4753 
  4754 * isatool usedir: new option -C (default true) controls whether option
  4755 -D should include a copy of the original document directory; -C false
  4756 prevents unwanted effects such as copying of administrative CVS data.
  4757 
  4758 
  4759 *** Pure ***
  4760 
  4761 * Considerably improved version of 'constdefs' command.  Now performs
  4762 automatic type-inference of declared constants; additional support for
  4763 local structure declarations (cf. locales and HOL records), see also
  4764 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4765 sequential dependencies of definitions within a single 'constdefs'
  4766 section; moreover, the declared name needs to be an identifier.  If
  4767 all fails, consider to fall back on 'consts' and 'defs' separately.
  4768 
  4769 * Improved indexed syntax and implicit structures.  First of all,
  4770 indexed syntax provides a notational device for subscripted
  4771 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4772 expressions.  Secondly, in a local context with structure
  4773 declarations, number indexes \<^sub>n or the empty index (default
  4774 number 1) refer to a certain fixed variable implicitly; option
  4775 show_structs controls printing of implicit structures.  Typical
  4776 applications of these concepts involve record types and locales.
  4777 
  4778 * New command 'no_syntax' removes grammar declarations (and
  4779 translations) resulting from the given syntax specification, which is
  4780 interpreted in the same manner as for the 'syntax' command.
  4781 
  4782 * 'Advanced' translation functions (parse_translation etc.) may depend
  4783 on the signature of the theory context being presently used for
  4784 parsing/printing, see also isar-ref manual.
  4785 
  4786 * Improved 'oracle' command provides a type-safe interface to turn an
  4787 ML expression of type theory -> T -> term into a primitive rule of
  4788 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4789 is already included here); see also FOL/ex/IffExample.thy;
  4790 INCOMPATIBILITY.
  4791 
  4792 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4793 before); "cI" is no longer bound, use "c.intro" instead.
  4794 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4795 axclasses vs. locales.
  4796 
  4797 * Improved internal renaming of symbolic identifiers -- attach primes
  4798 instead of base 26 numbers.
  4799 
  4800 * New flag show_question_marks controls printing of leading question
  4801 marks in schematic variable names.
  4802 
  4803 * In schematic variable names, *any* symbol following \<^isub> or
  4804 \<^isup> is now treated as part of the base name.  For example, the
  4805 following works without printing of awkward ".0" indexes:
  4806 
  4807   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4808     by simp
  4809 
  4810 * Inner syntax includes (*(*nested*) comments*).
  4811 
  4812 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4813 annotations as "(00...)".
  4814 
  4815 * Clear separation of logical types and nonterminals, where the latter
  4816 may only occur in 'syntax' specifications or type abbreviations.
  4817 Before that distinction was only partially implemented via type class
  4818 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4819 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4820 exotic syntax specifications may require further adaption
  4821 (e.g. Cube/Cube.thy).
  4822 
  4823 * Removed obsolete type class "logic", use the top sort {} instead.
  4824 Note that non-logical types should be declared as 'nonterminals'
  4825 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4826 specifications.
  4827 
  4828 * Attributes 'induct' and 'cases': type or set names may now be
  4829 locally fixed variables as well.
  4830 
  4831 * Simplifier: can now control the depth to which conditional rewriting
  4832 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4833 Limit.
  4834 
  4835 * Simplifier: simplification procedures may now take the current
  4836 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4837 interface), which is very useful for calling the Simplifier
  4838 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4839 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4840 low-level mk_simproc no longer applies Logic.varify internally, to
  4841 allow for use in a context of fixed variables.
  4842 
  4843 * thin_tac now works even if the assumption being deleted contains !!
  4844 or ==>.  More generally, erule now works even if the major premise of
  4845 the elimination rule contains !! or ==>.
  4846 
  4847 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4848 
  4849 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4850 from Pure, which contains all common declarations already.  Both
  4851 theories are defined via plain Isabelle/Isar .thy files.
  4852 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4853 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4854 use isatool fixcpure to adapt your theory and ML sources.
  4855 
  4856 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4857 selections of theorems in named facts via index ranges.
  4858 
  4859 * 'print_theorems': in theory mode, really print the difference
  4860 wrt. the last state (works for interactive theory development only),
  4861 in proof mode print all local facts (cf. 'print_facts');
  4862 
  4863 * 'hide': option '(open)' hides only base names.
  4864 
  4865 * More efficient treatment of intermediate checkpoints in interactive
  4866 theory development.
  4867 
  4868 * Code generator is now invoked via code_module (incremental code
  4869 generation) and code_library (modular code generation, ML structures
  4870 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4871 must be quoted when used as identifiers.
  4872 
  4873 * New 'value' command for reading, evaluating and printing terms using
  4874 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4875 quoted when used as identifier.
  4876 
  4877 
  4878 *** Locales ***
  4879 
  4880 * New commands for the interpretation of locale expressions in
  4881 theories (1), locales (2) and proof contexts (3).  These generate
  4882 proof obligations from the expression specification.  After the
  4883 obligations have been discharged, theorems of the expression are added
  4884 to the theory, target locale or proof context.  The synopsis of the
  4885 commands is a follows:
  4886 
  4887   (1) interpretation expr inst
  4888   (2) interpretation target < expr
  4889   (3) interpret expr inst
  4890 
  4891 Interpretation in theories and proof contexts require a parameter
  4892 instantiation of terms from the current context.  This is applied to
  4893 specifications and theorems of the interpreted expression.
  4894 Interpretation in locales only permits parameter renaming through the
  4895 locale expression.  Interpretation is smart in that interpretations
  4896 that are active already do not occur in proof obligations, neither are
  4897 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4898 inspect active interpretations of a particular locale.  For details,
  4899 see the Isar Reference manual.  Examples can be found in
  4900 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4901 
  4902 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4903 'interpret' instead.
  4904 
  4905 * New context element 'constrains' for adding type constraints to
  4906 parameters.
  4907 
  4908 * Context expressions: renaming of parameters with syntax
  4909 redeclaration.
  4910 
  4911 * Locale declaration: 'includes' disallowed.
  4912 
  4913 * Proper static binding of attribute syntax -- i.e. types / terms /
  4914 facts mentioned as arguments are always those of the locale definition
  4915 context, independently of the context of later invocations.  Moreover,
  4916 locale operations (renaming and type / term instantiation) are applied
  4917 to attribute arguments as expected.
  4918 
  4919 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4920 actual attributes; rare situations may require Attrib.attribute to
  4921 embed those attributes into Attrib.src that lack concrete syntax.
  4922 Attribute implementations need to cooperate properly with the static
  4923 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4924 Attrib.XXX_thm etc. already do the right thing without further
  4925 intervention.  Only unusual applications -- such as "where" or "of"
  4926 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4927 on the context and the facts involved -- may have to assign parsed
  4928 values to argument tokens explicitly.
  4929 
  4930 * Changed parameter management in theorem generation for long goal
  4931 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4932 theorem statement in rare situations.
  4933 
  4934 * Locale inspection command 'print_locale' omits notes elements.  Use
  4935 'print_locale!' to have them included in the output.
  4936 
  4937 
  4938 *** Provers ***
  4939 
  4940 * Provers/hypsubst.ML: improved version of the subst method, for
  4941 single-step rewriting: it now works in bound variable contexts. New is
  4942 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4943 rewrite a different subterm than the original subst method, which is
  4944 still available as 'simplesubst'.
  4945 
  4946 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4947 and quasi orders.
  4948 
  4949 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4950 reflexive-transitive closure of relations.
  4951 
  4952 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4953 limit (previously hard-coded with a value of 20) user-definable.
  4954 
  4955 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4956 is peformed already.  Object-logics merely need to finish their
  4957 initial simpset configuration as before.  INCOMPATIBILITY.
  4958 
  4959 
  4960 *** HOL ***
  4961 
  4962 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4963 
  4964   syntax (epsilon)
  4965     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4966 
  4967 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4968 and x-symbol; use option '-m epsilon' to get it actually printed.
  4969 Moreover, the mathematically important symbolic identifier \<epsilon>
  4970 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4971 
  4972 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4973 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4974 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4975 support corresponding Isar calculations.
  4976 
  4977 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4978 instead of ":".
  4979 
  4980 * theory SetInterval: changed the syntax for open intervals:
  4981 
  4982   Old       New
  4983   {..n(}    {..<n}
  4984   {)n..}    {n<..}
  4985   {m..n(}   {m..<n}
  4986   {)m..n}   {m<..n}
  4987   {)m..n(}  {m<..<n}
  4988 
  4989 The old syntax is still supported but will disappear in the next
  4990 release.  For conversion use the following Emacs search and replace
  4991 patterns (these are not perfect but work quite well):
  4992 
  4993   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4994   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4995 
  4996 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4997 equalities in commutative rings; method 'algebra' provides a generic
  4998 interface.
  4999 
  5000 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5001 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5002 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5003 be a tuple pattern.
  5004 
  5005 Some new syntax forms are available:
  5006 
  5007   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5008   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5009   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5010   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5011 
  5012 The latter form "\<Sum>x < k. e" used to be based on a separate
  5013 function "Summation", which has been discontinued.
  5014 
  5015 * theory Finite_Set: in structured induction proofs, the insert case
  5016 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5017 (insert F x)'.
  5018 
  5019 * The 'refute' command has been extended to support a much larger
  5020 fragment of HOL, including axiomatic type classes, constdefs and
  5021 typedefs, inductive datatypes and recursion.
  5022 
  5023 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5024 Requires zChaff with proof generation to be installed.  See
  5025 HOL/ex/SAT_Examples.thy for examples.
  5026 
  5027 * Datatype induction via method 'induct' now preserves the name of the
  5028 induction variable. For example, when proving P(xs::'a list) by
  5029 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5030 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5031 in unstructured proof scripts.
  5032 
  5033 * Reworked implementation of records.  Improved scalability for
  5034 records with many fields, avoiding performance problems for type
  5035 inference. Records are no longer composed of nested field types, but
  5036 of nested extension types. Therefore the record type only grows linear
  5037 in the number of extensions and not in the number of fields.  The
  5038 top-level (users) view on records is preserved.  Potential
  5039 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5040 old record representation. The type generated for a record is called
  5041 <record_name>_ext_type.
  5042 
  5043 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5044 proofs triggered by a record definition or a simproc (if
  5045 quick_and_dirty is enabled).  Definitions of large records can take
  5046 quite long.
  5047 
  5048 New simproc record_upd_simproc for simplification of multiple record
  5049 updates enabled by default.  Moreover, trivial updates are also
  5050 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5051 occasionally, since simplification is more powerful by default.
  5052 
  5053 * typedef: proper support for polymorphic sets, which contain extra
  5054 type-variables in the term.
  5055 
  5056 * Simplifier: automatically reasons about transitivity chains
  5057 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5058 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5059 old proofs break occasionally as simplification may now solve more
  5060 goals than previously.
  5061 
  5062 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5063 present.  Works for all partial orders (class "order"), in particular
  5064 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5065 just like y <= x.
  5066 
  5067 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5068 bound variable or a constant then the let is unfolded.  Otherwise
  5069 first a is simplified to b, and then f b is simplified to g. If
  5070 possible we abstract b from g arriving at "let x = b in h x",
  5071 otherwise we unfold the let and arrive at g.  The simproc can be
  5072 enabled/disabled by the reference use_let_simproc.  Potential
  5073 INCOMPATIBILITY since simplification is more powerful by default.
  5074 
  5075 * Classical reasoning: the meson method now accepts theorems as arguments.
  5076 
  5077 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5078 jobs to provide advice on the provability of subgoals.
  5079 
  5080 * Theory OrderedGroup and Ring_and_Field: various additions and
  5081 improvements to faciliate calculations involving equalities and
  5082 inequalities.
  5083 
  5084 The following theorems have been eliminated or modified
  5085 (INCOMPATIBILITY):
  5086 
  5087   abs_eq             now named abs_of_nonneg
  5088   abs_of_ge_0        now named abs_of_nonneg
  5089   abs_minus_eq       now named abs_of_nonpos
  5090   imp_abs_id         now named abs_of_nonneg
  5091   imp_abs_neg_id     now named abs_of_nonpos
  5092   mult_pos           now named mult_pos_pos
  5093   mult_pos_le        now named mult_nonneg_nonneg
  5094   mult_pos_neg_le    now named mult_nonneg_nonpos
  5095   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5096   mult_neg           now named mult_neg_neg
  5097   mult_neg_le        now named mult_nonpos_nonpos
  5098 
  5099 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5100      
  5101      zero_le_square
  5102      not_square_less_zero 
  5103 
  5104   The following lemmas have been deleted from Real/RealPow:
  5105   
  5106      realpow_zero_zero
  5107      realpow_two
  5108      realpow_less
  5109      zero_le_power
  5110      realpow_two_le
  5111      abs_realpow_two
  5112      realpow_two_abs     
  5113 
  5114 * Theory Parity: added rules for simplifying exponents.
  5115 
  5116 * Theory List:
  5117 
  5118 The following theorems have been eliminated or modified
  5119 (INCOMPATIBILITY):
  5120 
  5121   list_all_Nil       now named list_all.simps(1)
  5122   list_all_Cons      now named list_all.simps(2)
  5123   list_all_conv      now named list_all_iff
  5124   set_mem_eq         now named mem_iff
  5125 
  5126 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5127 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5128 
  5129 
  5130 *** HOL-Complex ***
  5131 
  5132 * Theory RealDef: better support for embedding natural numbers and
  5133 integers in the reals.
  5134 
  5135 The following theorems have been eliminated or modified
  5136 (INCOMPATIBILITY):
  5137 
  5138   exp_ge_add_one_self  now requires no hypotheses
  5139   real_of_int_add      reversed direction of equality (use [symmetric])
  5140   real_of_int_minus    reversed direction of equality (use [symmetric])
  5141   real_of_int_diff     reversed direction of equality (use [symmetric])
  5142   real_of_int_mult     reversed direction of equality (use [symmetric])
  5143 
  5144 * Theory RComplete: expanded support for floor and ceiling functions.
  5145 
  5146 * Theory Ln is new, with properties of the natural logarithm
  5147 
  5148 * Hyperreal: There is a new type constructor "star" for making
  5149 nonstandard types.  The old type names are now type synonyms:
  5150 
  5151   hypreal = real star
  5152   hypnat = nat star
  5153   hcomplex = complex star
  5154 
  5155 * Hyperreal: Many groups of similarly-defined constants have been
  5156 replaced by polymorphic versions (INCOMPATIBILITY):
  5157 
  5158   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5159 
  5160   starset      <-- starsetNat, starsetC
  5161   *s*          <-- *sNat*, *sc*
  5162   starset_n    <-- starsetNat_n, starsetC_n
  5163   *sn*         <-- *sNatn*, *scn*
  5164   InternalSets <-- InternalNatSets, InternalCSets
  5165 
  5166   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5167   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5168   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5169   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5170   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5171 
  5172 * Hyperreal: Many type-specific theorems have been removed in favor of
  5173 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5174 
  5175   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5176   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5177   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5178   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5179   right_minus <-- hypreal_add_minus
  5180   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5181   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5182   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5183   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5184   mult_1_right <-- hcomplex_mult_one_right
  5185   mult_zero_left <-- hcomplex_mult_zero_left
  5186   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5187   right_distrib <-- hypnat_add_mult_distrib2
  5188   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5189   right_inverse <-- hypreal_mult_inverse
  5190   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5191   order_refl <-- {hypreal,hypnat}_le_refl
  5192   order_trans <-- {hypreal,hypnat}_le_trans
  5193   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5194   order_less_le <-- {hypreal,hypnat}_less_le
  5195   linorder_linear <-- {hypreal,hypnat}_le_linear
  5196   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5197   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5198   add_nonneg_nonneg <-- hypreal_le_add_order
  5199 
  5200 * Hyperreal: Separate theorems having to do with type-specific
  5201 versions of constants have been merged into theorems that apply to the
  5202 new polymorphic constants (INCOMPATIBILITY):
  5203 
  5204   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5205   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5206   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5207   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5208   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5209   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5210   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5211   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5212   STAR_diff <-- {STAR,STARC}_diff
  5213   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5214     STARC_hcomplex_of_complex}_image_subset
  5215   starset_n_Un <-- starset{Nat,C}_n_Un
  5216   starset_n_Int <-- starset{Nat,C}_n_Int
  5217   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5218   starset_n_diff <-- starset{Nat,C}_n_diff
  5219   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5220   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5221   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5222   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5223   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5224   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5225   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5226   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5227   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5228   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5229   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5230   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5231   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5232   starfun_diff <-- starfun{C,RC,CR}_diff
  5233   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5234   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5235   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5236   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5237   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5238   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5239   starfun_Id <-- starfunC_Id
  5240   starfun_approx <-- starfun{Nat,CR}_approx
  5241   starfun_capprox <-- starfun{C,RC}_capprox
  5242   starfun_abs <-- starfunNat_rabs
  5243   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5244   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5245   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5246   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5247   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5248   starfun_add_approx <-- starfunCR_add_approx
  5249   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5250   starfun_divide <-- starfun{C,CR,RC}_divide
  5251   starfun_n <-- starfun{Nat,C}_n
  5252   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5253   starfun_n_add <-- starfun{Nat,C}_n_add
  5254   starfun_n_add_minus <-- starfunNat_n_add_minus
  5255   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5256   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5257   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5258 
  5259   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5260   star_n_minus <-- {hypreal,hcomplex}_minus
  5261   star_n_diff <-- {hypreal,hcomplex}_diff
  5262   star_n_mult <-- {hypreal,hcomplex}_mult
  5263   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5264   star_n_le <-- {hypreal,hypnat}_le
  5265   star_n_less <-- {hypreal,hypnat}_less
  5266   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5267   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5268   star_n_abs <-- hypreal_hrabs
  5269   star_n_divide <-- hcomplex_divide
  5270 
  5271   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5272   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5273   star_of_diff <-- hypreal_of_real_diff
  5274   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5275   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5276   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5277   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5278   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5279   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5280   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5281   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5282   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5283   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5284   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5285   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5286   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5287   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5288   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5289   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5290   star_of_power <-- hypreal_of_real_power
  5291   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5292 
  5293 * Hyperreal: new method "transfer" that implements the transfer
  5294 principle of nonstandard analysis. With a subgoal that mentions
  5295 nonstandard types like "'a star", the command "apply transfer"
  5296 replaces it with an equivalent one that mentions only standard types.
  5297 To be successful, all free variables must have standard types; non-
  5298 standard variables must have explicit universal quantifiers.
  5299 
  5300 * Hyperreal: A theory of Taylor series.
  5301 
  5302 
  5303 *** HOLCF ***
  5304 
  5305 * Discontinued special version of 'constdefs' (which used to support
  5306 continuous functions) in favor of the general Pure one with full
  5307 type-inference.
  5308 
  5309 * New simplification procedure for solving continuity conditions; it
  5310 is much faster on terms with many nested lambda abstractions (cubic
  5311 instead of exponential time).
  5312 
  5313 * New syntax for domain package: selector names are now optional.
  5314 Parentheses should be omitted unless argument is lazy, for example:
  5315 
  5316   domain 'a stream = cons "'a" (lazy "'a stream")
  5317 
  5318 * New command 'fixrec' for defining recursive functions with pattern
  5319 matching; defining multiple functions with mutual recursion is also
  5320 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5321 sinr, or any data constructor defined by the domain package. The given
  5322 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5323 syntax and examples.
  5324 
  5325 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5326 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5327 but the proof obligation additionally includes an admissibility
  5328 requirement. The packages generate instances of class cpo or pcpo,
  5329 with continuity and strictness theorems for Rep and Abs.
  5330 
  5331 * HOLCF: Many theorems have been renamed according to a more standard naming
  5332 scheme (INCOMPATIBILITY):
  5333 
  5334   foo_inject:  "foo$x = foo$y ==> x = y"
  5335   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5336   foo_less:    "(foo$x << foo$y) = (x << y)"
  5337   foo_strict:  "foo$UU = UU"
  5338   foo_defined: "... ==> foo$x ~= UU"
  5339   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5340 
  5341 
  5342 *** ZF ***
  5343 
  5344 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5345 including the First Isomorphism Theorem (on quotienting by the kernel
  5346 of a homomorphism).
  5347 
  5348 * ZF/Simplifier: install second copy of type solver that actually
  5349 makes use of TC rules declared to Isar proof contexts (or locales);
  5350 the old version is still required for ML proof scripts.
  5351 
  5352 
  5353 *** Cube ***
  5354 
  5355 * Converted to Isar theory format; use locales instead of axiomatic
  5356 theories.
  5357 
  5358 
  5359 *** ML ***
  5360 
  5361 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5362 for ||>, ||>>, |>>,
  5363 
  5364 * Pure/library.ML no longer defines its own option datatype, but uses
  5365 that of the SML basis, which has constructors NONE and SOME instead of
  5366 None and Some, as well as exception Option.Option instead of OPTION.
  5367 The functions the, if_none, is_some, is_none have been adapted
  5368 accordingly, while Option.map replaces apsome.
  5369 
  5370 * Pure/library.ML: the exception LIST has been given up in favour of
  5371 the standard exceptions Empty and Subscript, as well as
  5372 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5373 superceded by the standard hd and tl functions etc.
  5374 
  5375 A number of basic list functions are no longer exported to the ML
  5376 toplevel, as they are variants of predefined functions.  The following
  5377 suggests how one can translate existing code:
  5378 
  5379     rev_append xs ys = List.revAppend (xs, ys)
  5380     nth_elem (i, xs) = List.nth (xs, i)
  5381     last_elem xs = List.last xs
  5382     flat xss = List.concat xss
  5383     seq fs = List.app fs
  5384     partition P xs = List.partition P xs
  5385     mapfilter f xs = List.mapPartial f xs
  5386 
  5387 * Pure/library.ML: several combinators for linear functional
  5388 transformations, notably reverse application and composition:
  5389 
  5390   x |> f                f #> g
  5391   (x, y) |-> f          f #-> g
  5392 
  5393 * Pure/library.ML: introduced/changed precedence of infix operators:
  5394 
  5395   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5396   infix 2 ?;
  5397   infix 3 o oo ooo oooo;
  5398   infix 4 ~~ upto downto;
  5399 
  5400 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5401 infix operators.
  5402 
  5403 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5404 fold_map support linear functional transformations and nesting.  For
  5405 example:
  5406 
  5407   fold f [x1, ..., xN] y =
  5408     y |> f x1 |> ... |> f xN
  5409 
  5410   (fold o fold) f [xs1, ..., xsN] y =
  5411     y |> fold f xs1 |> ... |> fold f xsN
  5412 
  5413   fold f [x1, ..., xN] =
  5414     f x1 #> ... #> f xN
  5415 
  5416   (fold o fold) f [xs1, ..., xsN] =
  5417     fold f xs1 #> ... #> fold f xsN
  5418 
  5419 * Pure/library.ML: the following selectors on type 'a option are
  5420 available:
  5421 
  5422   the:               'a option -> 'a  (*partial*)
  5423   these:             'a option -> 'a  where 'a = 'b list
  5424   the_default: 'a -> 'a option -> 'a
  5425   the_list:          'a option -> 'a list
  5426 
  5427 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5428 basic operations for association lists, following natural argument
  5429 order; moreover the explicit equality predicate passed here avoids
  5430 potentially expensive polymorphic runtime equality checks.
  5431 The old functions may be expressed as follows:
  5432 
  5433   assoc = uncurry (AList.lookup (op =))
  5434   assocs = these oo AList.lookup (op =)
  5435   overwrite = uncurry (AList.update (op =)) o swap
  5436 
  5437 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5438 
  5439   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5440   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5441 
  5442 replacing make_keylist and keyfilter (occassionally used)
  5443 Naive rewrites:
  5444 
  5445   make_keylist = AList.make
  5446   keyfilter = AList.find (op =)
  5447 
  5448 * eq_fst and eq_snd now take explicit equality parameter, thus
  5449   avoiding eqtypes. Naive rewrites:
  5450 
  5451     eq_fst = eq_fst (op =)
  5452     eq_snd = eq_snd (op =)
  5453 
  5454 * Removed deprecated apl and apr (rarely used).
  5455   Naive rewrites:
  5456 
  5457     apl (n, op) =>>= curry op n
  5458     apr (op, m) =>>= fn n => op (n, m)
  5459 
  5460 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5461 provides a reasonably efficient light-weight implementation of sets as
  5462 lists.
  5463 
  5464 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5465 few new operations; existing lookup and update are now curried to
  5466 follow natural argument order (for use with fold etc.);
  5467 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5468 
  5469 * Pure/General: output via the Isabelle channels of
  5470 writeln/warning/error etc. is now passed through Output.output, with a
  5471 hook for arbitrary transformations depending on the print_mode
  5472 (cf. Output.add_mode -- the first active mode that provides a output
  5473 function wins).  Already formatted output may be embedded into further
  5474 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5475 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5476 accommodate easy composition of diagnostic messages etc.  Programmers
  5477 rarely need to care about Output.output or Output.raw at all, with
  5478 some notable exceptions: Output.output is required when bypassing the
  5479 standard channels (writeln etc.), or in token translations to produce
  5480 properly formatted results; Output.raw is required when capturing
  5481 already output material that will eventually be presented to the user
  5482 a second time.  For the default print mode, both Output.output and
  5483 Output.raw have no effect.
  5484 
  5485 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5486 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5487 cumulative results are displayed at the end of a batch session.
  5488 
  5489 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5490 replaced by File.platform_path and File.shell_path (with appropriate
  5491 hooks).  This provides a clean interface for unusual systems where the
  5492 internal and external process view of file names are different.
  5493 
  5494 * Pure: more efficient orders for basic syntactic entities: added
  5495 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5496 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5497 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5498 orders now -- potential INCOMPATIBILITY for code that depends on a
  5499 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5500 Library.sort_strings on result).
  5501 
  5502 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5503 fold_types traverse types/terms from left to right, observing natural
  5504 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5505 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5506 
  5507 * Pure: name spaces have been refined, with significant changes of the
  5508 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5509 to extern(_table).  The plain name entry path is superceded by a
  5510 general 'naming' context, which also includes the 'policy' to produce
  5511 a fully qualified name and external accesses of a fully qualified
  5512 name; NameSpace.extend is superceded by context dependent
  5513 Sign.declare_name.  Several theory and proof context operations modify
  5514 the naming context.  Especially note Theory.restore_naming and
  5515 ProofContext.restore_naming to get back to a sane state; note that
  5516 Theory.add_path is no longer sufficient to recover from
  5517 Theory.absolute_path in particular.
  5518 
  5519 * Pure: new flags short_names (default false) and unique_names
  5520 (default true) for controlling output of qualified names.  If
  5521 short_names is set, names are printed unqualified.  If unique_names is
  5522 reset, the name prefix is reduced to the minimum required to achieve
  5523 the original result when interning again, even if there is an overlap
  5524 with earlier declarations.
  5525 
  5526 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5527 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5528 (useful for printing error messages).  INCOMPATIBILITY.
  5529 
  5530 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5531 Theory.theory are now identified, referring to the universal
  5532 Context.theory (see Pure/context.ML).  Actual signature and theory
  5533 content is managed as theory data.  The old code and interfaces were
  5534 spread over many files and structures; the new arrangement introduces
  5535 considerable INCOMPATIBILITY to gain more clarity:
  5536 
  5537   Context -- theory management operations (name, identity, inclusion,
  5538     parents, ancestors, merge, etc.), plus generic theory data;
  5539 
  5540   Sign -- logical signature and syntax operations (declaring consts,
  5541     types, etc.), plus certify/read for common entities;
  5542 
  5543   Theory -- logical theory operations (stating axioms, definitions,
  5544     oracles), plus a copy of logical signature operations (consts,
  5545     types, etc.); also a few basic management operations (Theory.copy,
  5546     Theory.merge, etc.)
  5547 
  5548 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5549 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5550 for convenience -- they merely return the theory.
  5551 
  5552 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5553 
  5554 * Pure: the Isar proof context type is already defined early in Pure
  5555 as Context.proof (note that ProofContext.context and Proof.context are
  5556 aliases, where the latter is the preferred name).  This enables other
  5557 Isabelle components to refer to that type even before Isar is present.
  5558 
  5559 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5560 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5561 any of these kinds.  For example, Sign.intern typeK is now
  5562 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5563 Theory.hide_types.  Also note that former
  5564 Theory.hide_classes/types/consts are now
  5565 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5566 internalize their arguments!  INCOMPATIBILITY.
  5567 
  5568 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5569 datatype thmref (with constructors Name and NameSelection) instead of
  5570 plain string -- INCOMPATIBILITY;
  5571 
  5572 * Pure: cases produced by proof methods specify options, where NONE
  5573 means to remove case bindings -- INCOMPATIBILITY in
  5574 (RAW_)METHOD_CASES.
  5575 
  5576 * Pure: the following operations retrieve axioms or theorems from a
  5577 theory node or theory hierarchy, respectively:
  5578 
  5579   Theory.axioms_of: theory -> (string * term) list
  5580   Theory.all_axioms_of: theory -> (string * term) list
  5581   PureThy.thms_of: theory -> (string * thm) list
  5582   PureThy.all_thms_of: theory -> (string * thm) list
  5583 
  5584 * Pure: print_tac now outputs the goal through the trace channel.
  5585 
  5586 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5587 Reference Toplevel.debug (default false) controls detailed printing
  5588 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5589 controls execution profiling -- set to 1 for time and 2 for space
  5590 (both increase the runtime).
  5591 
  5592 * Isar session: The initial use of ROOT.ML is now always timed,
  5593 i.e. the log will show the actual process times, in contrast to the
  5594 elapsed wall-clock time that the outer shell wrapper produces.
  5595 
  5596 * Simplifier: improved handling of bound variables (nameless
  5597 representation, avoid allocating new strings).  Simprocs that invoke
  5598 the Simplifier recursively should use Simplifier.inherit_bounds to
  5599 avoid local name clashes.  Failure to do so produces warnings
  5600 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5601 for further details.
  5602 
  5603 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5604 bindings for all theorems stored within a given theory; this may help
  5605 in porting non-Isar theories to Isar ones, while keeping ML proof
  5606 scripts for the time being.
  5607 
  5608 * ML operator HTML.with_charset specifies the charset begin used for
  5609 generated HTML files.  For example:
  5610 
  5611   HTML.with_charset "utf-8" use_thy "Hebrew";
  5612   HTML.with_charset "utf-8" use_thy "Chinese";
  5613 
  5614 
  5615 *** System ***
  5616 
  5617 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5618 isabelle, isatool etc.).
  5619 
  5620 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5621 isatool doc, isatool mkdir, display_drafts etc.).
  5622 
  5623 * isatool usedir: option -f allows specification of the ML file to be
  5624 used by Isabelle; default is ROOT.ML.
  5625 
  5626 * New isatool version outputs the version identifier of the Isabelle
  5627 distribution being used.
  5628 
  5629 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5630 (containing Boolean satisfiability problems) into Isabelle/HOL
  5631 theories.
  5632 
  5633 
  5634 
  5635 New in Isabelle2004 (April 2004)
  5636 --------------------------------
  5637 
  5638 *** General ***
  5639 
  5640 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5641   Replaces linorder.ML.
  5642 
  5643 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5644   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5645   (\<a>...\<z>), are now considered normal letters, and can therefore
  5646   be used anywhere where an ASCII letter (a...zA...Z) has until
  5647   now. COMPATIBILITY: This obviously changes the parsing of some
  5648   terms, especially where a symbol has been used as a binder, say
  5649   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5650   as an identifier.  Fix it by inserting a space around former
  5651   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5652   existing theory and ML files.
  5653 
  5654 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5655 
  5656 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5657   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5658   a normal (but invisible) letter. For multiple letter subscripts repeat
  5659   \<^isub> like this: x\<^isub>1\<^isub>2.
  5660 
  5661 * Pure: There are now sub-/superscripts that can span more than one
  5662   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5663   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5664   superscript. The new control characters are not identifier parts.
  5665 
  5666 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5667   content of "..." to the latex file instead of \isacntrl... . The "..."
  5668   may consist of any printable characters excluding the end bracket >.
  5669 
  5670 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5671   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5672   declare constants "final", which prevents their being given a definition
  5673   later.  It is useful for constants whose behaviour is fixed axiomatically
  5674   rather than definitionally, such as the meta-logic connectives.
  5675 
  5676 * Pure: 'instance' now handles general arities with general sorts
  5677   (i.e. intersections of classes),
  5678 
  5679 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5680   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5681   It can be changed to alter the colors/layout of generated pages.
  5682 
  5683 
  5684 *** Isar ***
  5685 
  5686 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5687   cut_tac, subgoal_tac and thin_tac:
  5688   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5689     locales are no longer forced to write Isar proof scripts.
  5690     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5691     emulations.
  5692   - INCOMPATIBILITY: names of variables to be instantiated may no
  5693     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5694     This is consistent with the instantiation attribute "where".
  5695 
  5696 * Attributes "where" and "of":
  5697   - Now take type variables of instantiated theorem into account when reading
  5698     the instantiation string.  This fixes a bug that caused instantiated
  5699     theorems to have too special types in some circumstances.
  5700   - "where" permits explicit instantiations of type variables.
  5701 
  5702 * Calculation commands "moreover" and "also" no longer interfere with
  5703   current facts ("this"), admitting arbitrary combinations with "then"
  5704   and derived forms.
  5705 
  5706 * Locales:
  5707   - Goal statements involving the context element "includes" no longer
  5708     generate theorems with internal delta predicates (those ending on
  5709     "_axioms") in the premise.
  5710     Resolve particular premise with <locale>.intro to obtain old form.
  5711   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5712     specification and "includes" elements in goal statement.
  5713   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5714     [intro?] and [elim?] (respectively) by default.
  5715   - Experimental command for instantiation of locales in proof contexts:
  5716         instantiate <label>[<attrs>]: <loc>
  5717     Instantiates locale <loc> and adds all its theorems to the current context
  5718     taking into account their attributes.  Label and attrs are optional
  5719     modifiers, like in theorem declarations.  If present, names of
  5720     instantiated theorems are qualified with <label>, and the attributes
  5721     <attrs> are applied after any attributes these theorems might have already.
  5722       If the locale has assumptions, a chained fact of the form
  5723     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5724     are derived.  The command does not support old-style locales declared
  5725     with "locale (open)".
  5726       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5727 
  5728 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5729   (Isar) contexts.
  5730 
  5731 
  5732 *** HOL ***
  5733 
  5734 * Proof import: new image HOL4 contains the imported library from
  5735   the HOL4 system with about 2500 theorems. It is imported by
  5736   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5737   can be used like any other Isabelle image.  See
  5738   HOL/Import/HOL/README for more information.
  5739 
  5740 * Simplifier:
  5741   - Much improved handling of linear and partial orders.
  5742     Reasoners for linear and partial orders are set up for type classes
  5743     "linorder" and "order" respectively, and are added to the default simpset
  5744     as solvers.  This means that the simplifier can build transitivity chains
  5745     to solve goals from the assumptions.
  5746   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5747     of blast or auto after simplification become unnecessary because the goal
  5748     is solved by simplification already.
  5749 
  5750 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5751     all proved in axiomatic type classes for semirings, rings and fields.
  5752 
  5753 * Numerics:
  5754   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5755     now formalized using the Ring_and_Field theory mentioned above.
  5756   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5757     than before, because now they are set up once in a generic manner.
  5758   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5759     Look for the general versions in Ring_and_Field (and Power if they concern
  5760     exponentiation).
  5761 
  5762 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5763 
  5764 * Records:
  5765   - Record types are now by default printed with their type abbreviation
  5766     instead of the list of all field types. This can be configured via
  5767     the reference "print_record_type_abbr".
  5768   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5769     (not enabled by default).
  5770   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5771     EX x. x = sel r to True (not enabled by default).
  5772   - Tactic "record_split_simp_tac" to split and simplify records added.
  5773 
  5774 * 'specification' command added, allowing for definition by
  5775   specification.  There is also an 'ax_specification' command that
  5776   introduces the new constants axiomatically.
  5777 
  5778 * arith(_tac) is now able to generate counterexamples for reals as well.
  5779 
  5780 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5781 
  5782 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5783   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5784 
  5785 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5786   matrix theory to linear programming.
  5787 
  5788 * Unions and Intersections:
  5789   The latex output syntax of UN and INT has been changed
  5790   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5791   i.e. the index formulae has become a subscript.
  5792   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5793 
  5794 * Unions and Intersections over Intervals:
  5795   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5796   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5797   like in normal math, and corresponding versions for < and for intersection.
  5798 
  5799 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5800   lexicographic dictonary ordering has been added as "lexord".
  5801 
  5802 * ML: the legacy theory structures Int and List have been removed. They had
  5803   conflicted with ML Basis Library structures having the same names.
  5804 
  5805 * 'refute' command added to search for (finite) countermodels.  Only works
  5806   for a fragment of HOL.  The installation of an external SAT solver is
  5807   highly recommended.  See "HOL/Refute.thy" for details.
  5808 
  5809 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5810   formulae under an assignment of free variables to random values.
  5811   In contrast to 'refute', it can deal with inductive datatypes,
  5812   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5813   for examples.
  5814 
  5815 
  5816 *** HOLCF ***
  5817 
  5818 * Streams now come with concatenation and are part of the HOLCF image
  5819 
  5820 
  5821 
  5822 New in Isabelle2003 (May 2003)
  5823 ------------------------------
  5824 
  5825 *** General ***
  5826 
  5827 * Provers/simplifier:
  5828 
  5829   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5830     Assumptions are now subject to complete mutual simplification,
  5831     not just from left to right. The simplifier now preserves
  5832     the order of assumptions.
  5833 
  5834     Potential INCOMPATIBILITY:
  5835 
  5836     -- simp sometimes diverges where the old version did
  5837        not, e.g. invoking simp on the goal
  5838 
  5839         [| P (f x); y = x; f x = f y |] ==> Q
  5840 
  5841        now gives rise to the infinite reduction sequence
  5842 
  5843         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5844 
  5845        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5846        kind of problem.
  5847 
  5848     -- Tactics combining classical reasoner and simplification (such as auto)
  5849        are also affected by this change, because many of them rely on
  5850        simp. They may sometimes diverge as well or yield a different numbers
  5851        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5852        in case of problems. Sometimes subsequent calls to the classical
  5853        reasoner will fail because a preceeding call to the simplifier too
  5854        eagerly simplified the goal, e.g. deleted redundant premises.
  5855 
  5856   - The simplifier trace now shows the names of the applied rewrite rules
  5857 
  5858   - You can limit the number of recursive invocations of the simplifier
  5859     during conditional rewriting (where the simplifie tries to solve the
  5860     conditions before applying the rewrite rule):
  5861     ML "simp_depth_limit := n"
  5862     where n is an integer. Thus you can force termination where previously
  5863     the simplifier would diverge.
  5864 
  5865   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5866 
  5867   - No longer aborts on failed congruence proof.  Instead, the
  5868     congruence is ignored.
  5869 
  5870 * Pure: New generic framework for extracting programs from constructive
  5871   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5872   as HOL/Extraction for some case studies.
  5873 
  5874 * Pure: The main goal of the proof state is no longer shown by default, only
  5875 the subgoals. This behaviour is controlled by a new flag.
  5876    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5877 (ML: Proof.show_main_goal).
  5878 
  5879 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5880 rules whose conclusion matches subgoal 1:
  5881       PG menu: Isabelle/Isar -> Show me -> matching rules
  5882 The rules are ordered by how closely they match the subgoal.
  5883 In particular, rules that solve a subgoal outright are displayed first
  5884 (or rather last, the way they are printed).
  5885 (ML: ProofGeneral.print_intros())
  5886 
  5887 * Pure: New flag trace_unify_fail causes unification to print
  5888 diagnostic information (PG: in trace buffer) when it fails. This is
  5889 useful for figuring out why single step proofs like rule, erule or
  5890 assumption failed.
  5891 
  5892 * Pure: Locale specifications now produce predicate definitions
  5893 according to the body of text (covering assumptions modulo local
  5894 definitions); predicate "loc_axioms" covers newly introduced text,
  5895 while "loc" is cumulative wrt. all included locale expressions; the
  5896 latter view is presented only on export into the global theory
  5897 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5898 on the old view without predicates;
  5899 
  5900 * Pure: predefined locales "var" and "struct" are useful for sharing
  5901 parameters (as in CASL, for example); just specify something like
  5902 ``var x + var y + struct M'' as import;
  5903 
  5904 * Pure: improved thms_containing: proper indexing of facts instead of
  5905 raw theorems; check validity of results wrt. current name space;
  5906 include local facts of proof configuration (also covers active
  5907 locales), cover fixed variables in index; may use "_" in term
  5908 specification; an optional limit for the number of printed facts may
  5909 be given (the default is 40);
  5910 
  5911 * Pure: disallow duplicate fact bindings within new-style theory files
  5912 (batch-mode only);
  5913 
  5914 * Provers: improved induct method: assumptions introduced by case
  5915 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5916 the goal statement); "foo" still refers to all facts collectively;
  5917 
  5918 * Provers: the function blast.overloaded has been removed: all constants
  5919 are regarded as potentially overloaded, which improves robustness in exchange
  5920 for slight decrease in efficiency;
  5921 
  5922 * Provers/linorder: New generic prover for transitivity reasoning over
  5923 linear orders.  Note: this prover is not efficient!
  5924 
  5925 * Isar: preview of problems to finish 'show' now produce an error
  5926 rather than just a warning (in interactive mode);
  5927 
  5928 
  5929 *** HOL ***
  5930 
  5931 * arith(_tac)
  5932 
  5933  - Produces a counter example if it cannot prove a goal.
  5934    Note that the counter example may be spurious if the goal is not a formula
  5935    of quantifier-free linear arithmetic.
  5936    In ProofGeneral the counter example appears in the trace buffer.
  5937 
  5938  - Knows about div k and mod k where k is a numeral of type nat or int.
  5939 
  5940  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5941    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5942    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5943 
  5944 * simp's arithmetic capabilities have been enhanced a bit: it now
  5945 takes ~= in premises into account (by performing a case split);
  5946 
  5947 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5948 are distributed over a sum of terms;
  5949 
  5950 * New tactic "trans_tac" and method "trans" instantiate
  5951 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5952 "<=", "<" and "=").
  5953 
  5954 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5955 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5956 
  5957 * 'typedef' command has new option "open" to suppress the set
  5958 definition;
  5959 
  5960 * functions Min and Max on finite sets have been introduced (theory
  5961 Finite_Set);
  5962 
  5963 * attribute [symmetric] now works for relations as well; it turns
  5964 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5965 
  5966 * induct over a !!-quantified statement (say !!x1..xn):
  5967   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5968 
  5969 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5970 %x. None. Warning: empty_def now refers to the previously hidden definition
  5971 of the empty set.
  5972 
  5973 * Algebra: formalization of classical algebra.  Intended as base for
  5974 any algebraic development in Isabelle.  Currently covers group theory
  5975 (up to Sylow's theorem) and ring theory (Universal Property of
  5976 Univariate Polynomials).  Contributions welcome;
  5977 
  5978 * GroupTheory: deleted, since its material has been moved to Algebra;
  5979 
  5980 * Complex: new directory of the complex numbers with numeric constants,
  5981 nonstandard complex numbers, and some complex analysis, standard and
  5982 nonstandard (Jacques Fleuriot);
  5983 
  5984 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5985 
  5986 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5987 Fleuriot);
  5988 
  5989 * Real/HahnBanach: updated and adapted to locales;
  5990 
  5991 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5992 Gray and Kramer);
  5993 
  5994 * UNITY: added the Meier-Sanders theory of progress sets;
  5995 
  5996 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5997 as abstract algorithms, instantiated to the JVM;
  5998 
  5999 * Bali: Java source language formalization. Type system, operational
  6000 semantics, axiomatic semantics. Supported language features:
  6001 classes, interfaces, objects,virtual methods, static methods,
  6002 static/instance fields, arrays, access modifiers, definite
  6003 assignment, exceptions.
  6004 
  6005 
  6006 *** ZF ***
  6007 
  6008 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6009 universe, etc.);
  6010 
  6011 * Main ZF: virtually all theories converted to new-style format;
  6012 
  6013 
  6014 *** ML ***
  6015 
  6016 * Pure: Tactic.prove provides sane interface for internal proofs;
  6017 omits the infamous "standard" operation, so this is more appropriate
  6018 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6019 
  6020 * Pure: improved error reporting of simprocs;
  6021 
  6022 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6023 up simprocs;
  6024 
  6025 
  6026 *** Document preparation ***
  6027 
  6028 * uses \par instead of \\ for line breaks in theory text. This may
  6029 shift some page breaks in large documents. To get the old behaviour
  6030 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6031 
  6032 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6033 other packages
  6034 
  6035 * \<euro> now needs package babel/greek instead of marvosym (which
  6036 broke \Rightarrow)
  6037 
  6038 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6039 textcomp package)
  6040 
  6041 
  6042 
  6043 New in Isabelle2002 (March 2002)
  6044 --------------------------------
  6045 
  6046 *** Document preparation ***
  6047 
  6048 * greatly simplified document preparation setup, including more
  6049 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6050 instructive isatool mkdir; users should basically be able to get
  6051 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6052 users may run a separate document processing stage manually like this:
  6053 "isatool usedir -D output HOL Test && isatool document Test/output";
  6054 
  6055 * theory dependency graph may now be incorporated into documents;
  6056 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6057 with \includegraphics of LaTeX;
  6058 
  6059 * proper spacing of consecutive markup elements, especially text
  6060 blocks after section headings;
  6061 
  6062 * support bold style (for single symbols only), input syntax is like
  6063 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6064 
  6065 * \<bullet> is now output as bold \cdot by default, which looks much
  6066 better in printed text;
  6067 
  6068 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6069 note that these symbols are currently unavailable in Proof General /
  6070 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6071 
  6072 * isatool latex no longer depends on changed TEXINPUTS, instead
  6073 isatool document copies the Isabelle style files to the target
  6074 location;
  6075 
  6076 
  6077 *** Isar ***
  6078 
  6079 * Pure/Provers: improved proof by cases and induction;
  6080   - 'case' command admits impromptu naming of parameters (such as
  6081     "case (Suc n)");
  6082   - 'induct' method divinates rule instantiation from the inductive
  6083     claim; no longer requires excessive ?P bindings for proper
  6084     instantiation of cases;
  6085   - 'induct' method properly enumerates all possibilities of set/type
  6086     rules; as a consequence facts may be also passed through *type*
  6087     rules without further ado;
  6088   - 'induct' method now derives symbolic cases from the *rulified*
  6089     rule (before it used to rulify cases stemming from the internal
  6090     atomized version); this means that the context of a non-atomic
  6091     statement becomes is included in the hypothesis, avoiding the
  6092     slightly cumbersome show "PROP ?case" form;
  6093   - 'induct' may now use elim-style induction rules without chaining
  6094     facts, using ``missing'' premises from the goal state; this allows
  6095     rules stemming from inductive sets to be applied in unstructured
  6096     scripts, while still benefitting from proper handling of non-atomic
  6097     statements; NB: major inductive premises need to be put first, all
  6098     the rest of the goal is passed through the induction;
  6099   - 'induct' proper support for mutual induction involving non-atomic
  6100     rule statements (uses the new concept of simultaneous goals, see
  6101     below);
  6102   - append all possible rule selections, but only use the first
  6103     success (no backtracking);
  6104   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6105   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6106   - added 'print_induct_rules' (covered by help item in recent Proof
  6107     General versions);
  6108   - moved induct/cases attributes to Pure, methods to Provers;
  6109   - generic method setup instantiated for FOL and HOL;
  6110 
  6111 * Pure: support multiple simultaneous goal statements, for example
  6112 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6113 meta-level mechanism, this acts as if several individual goals had
  6114 been stated separately; in particular common proof methods need to be
  6115 repeated in order to cover all claims; note that a single elimination
  6116 step is *not* sufficient to establish the two conjunctions, so this
  6117 fails:
  6118 
  6119   assume "A & B" then have A and B ..   (*".." fails*)
  6120 
  6121 better use "obtain" in situations as above; alternative refer to
  6122 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6123 
  6124 * Pure: proper integration with ``locales''; unlike the original
  6125 version by Florian Kammller, Isar locales package high-level proof
  6126 contexts rather than raw logical ones (e.g. we admit to include
  6127 attributes everywhere); operations on locales include merge and
  6128 rename; support for implicit arguments (``structures''); simultaneous
  6129 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6130 some examples;
  6131 
  6132 * Pure: the following commands have been ``localized'', supporting a
  6133 target locale specification "(in name)": 'lemma', 'theorem',
  6134 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6135 stored both within the locale and at the theory level (exported and
  6136 qualified by the locale name);
  6137 
  6138 * Pure: theory goals may now be specified in ``long'' form, with
  6139 ad-hoc contexts consisting of arbitrary locale elements. for example
  6140 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6141 definitions may be given, too); the result is a meta-level rule with
  6142 the context elements being discharged in the obvious way;
  6143 
  6144 * Pure: new proof command 'using' allows to augment currently used
  6145 facts after a goal statement ('using' is syntactically analogous to
  6146 'apply', but acts on the goal's facts only); this allows chained facts
  6147 to be separated into parts given before and after a claim, as in
  6148 ``from a and b have C using d and e <proof>'';
  6149 
  6150 * Pure: renamed "antecedent" case to "rule_context";
  6151 
  6152 * Pure: new 'judgment' command records explicit information about the
  6153 object-logic embedding (used by several tools internally); no longer
  6154 use hard-wired "Trueprop";
  6155 
  6156 * Pure: added 'corollary' command;
  6157 
  6158 * Pure: fixed 'token_translation' command;
  6159 
  6160 * Pure: removed obsolete 'exported' attribute;
  6161 
  6162 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6163 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6164 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6165 
  6166 * Pure: method 'atomize' presents local goal premises as object-level
  6167 statements (atomic meta-level propositions); setup controlled via
  6168 rewrite rules declarations of 'atomize' attribute; example
  6169 application: 'induct' method with proper rule statements in improper
  6170 proof *scripts*;
  6171 
  6172 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6173 now consider the syntactic context of assumptions, giving a better
  6174 chance to get type-inference of the arguments right (this is
  6175 especially important for locales);
  6176 
  6177 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6178 mode;
  6179 
  6180 * Pure/obtain: the formal conclusion "thesis", being marked as
  6181 ``internal'', may no longer be reference directly in the text;
  6182 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6183 situations;
  6184 
  6185 * Pure: generic 'sym' attribute which declares a rule both as pure
  6186 'elim?' and for the 'symmetric' operation;
  6187 
  6188 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6189 text; the fixed correlation with particular command syntax has been
  6190 discontinued;
  6191 
  6192 * Pure: new method 'rules' is particularly well-suited for proof
  6193 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6194 but often produces more compact proof terms with less detours;
  6195 
  6196 * Pure/Provers/classical: simplified integration with pure rule
  6197 attributes and methods; the classical "intro?/elim?/dest?"
  6198 declarations coincide with the pure ones; the "rule" method no longer
  6199 includes classically swapped intros; "intro" and "elim" methods no
  6200 longer pick rules from the context; also got rid of ML declarations
  6201 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6202 INCOMPATIBILITY;
  6203 
  6204 * Provers/classical: attribute 'swapped' produces classical inversions
  6205 of introduction rules;
  6206 
  6207 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6208 rules instead of full simplifier context; 'iff' attribute handles
  6209 conditional rules;
  6210 
  6211 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6212 
  6213 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6214 "(permissive)" option to recover old behavior;
  6215 
  6216 * HOL: 'inductive' no longer features separate (collective) attributes
  6217 for 'intros' (was found too confusing);
  6218 
  6219 * HOL: properly declared induction rules less_induct and
  6220 wf_induct_rule;
  6221 
  6222 
  6223 *** HOL ***
  6224 
  6225 * HOL: moved over to sane numeral syntax; the new policy is as
  6226 follows:
  6227 
  6228   - 0 and 1 are polymorphic constants, which are defined on any
  6229   numeric type (nat, int, real etc.);
  6230 
  6231   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
</