NEWS
author berghofe
Tue Nov 13 11:02:55 2007 +0100 (2007-11-13)
changeset 25425 9191942c4ead
parent 25409 b87196bb57da
child 25429 9e14fbd43e6b
permissions -rw-r--r--
Removed some case_names and consumes attributes that are now no longer
needed due to changes in the to_pred and to_set attributes.
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in Isabelle2007
     5 -------------------
     6 
     7 *** General ***
     8 
     9 * More uniform information about legacy features, notably a
    10 warning/error of "Legacy feature: ...", depending on the state of the
    11 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
    12 legacy features will disappear eventually.
    13 
    14 * Theory syntax: the header format ``theory A = B + C:'' has been
    15 discontinued in favour of ``theory A imports B C begin''.  Use isatool
    16 fixheaders to convert existing theory files.  INCOMPATIBILITY.
    17 
    18 * Theory syntax: the old non-Isar theory file format has been
    19 discontinued altogether.  Note that ML proof scripts may still be used
    20 with Isar theories; migration is usually quite simple with the ML
    21 function use_legacy_bindings.  INCOMPATIBILITY.
    22 
    23 * Theory syntax: some popular names (e.g. 'class', 'declaration',
    24 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
    25 quotes.
    26 
    27 * Theory loader: be more serious about observing the static theory
    28 header specifications (including optional directories), but not the
    29 accidental file locations of previously successful loads.  The strict
    30 update policy of former update_thy is now already performed by
    31 use_thy, so the former has been removed; use_thys updates several
    32 theories simultaneously, just as 'imports' within a theory header
    33 specification, but without merging the results.  Potential
    34 INCOMPATIBILITY: may need to refine theory headers and commands
    35 ROOT.ML which depend on load order.
    36 
    37 * Theory loader: optional support for content-based file
    38 identification, instead of the traditional scheme of full physical
    39 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
    40 (cf. the system manual).  The new scheme allows to work with
    41 non-finished theories in persistent session images, such that source
    42 files may be moved later on without requiring reloads.
    43 
    44 * Theory loader: old-style ML proof scripts being *attached* to a thy
    45 file (with the same base name as the theory) are considered a legacy
    46 feature, which will disappear eventually. Even now, the theory loader
    47 no longer maintains dependencies on such files.
    48 
    49 * Syntax: the scope for resolving ambiguities via type-inference is
    50 now limited to individual terms, instead of whole simultaneous
    51 specifications as before. This greatly reduces the complexity of the
    52 syntax module and improves flexibility by separating parsing and
    53 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
    54 'fixes' etc.) are required in rare situations.
    55 
    56 * Syntax: constants introduced by new-style packages ('definition',
    57 'abbreviation' etc.) are passed through the syntax module in
    58 ``authentic mode''. This means that associated mixfix annotations
    59 really stick to such constants, independently of potential name space
    60 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
    61 trees are represented slightly differently, may need to adapt syntax
    62 translations accordingly. Use CONST marker in 'translations' and
    63 @{const_syntax} antiquotation in 'parse_translation' etc.
    64 
    65 * Legacy goal package: reduced interface to the bare minimum required
    66 to keep existing proof scripts running.  Most other user-level
    67 functions are now part of the OldGoals structure, which is *not* open
    68 by default (consider isatool expandshort before open OldGoals).
    69 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
    70 these tend to cause confusion about the actual goal (!) context being
    71 used here, which is not necessarily the same as the_context().
    72 
    73 * Command 'find_theorems': supports "*" wild-card in "name:"
    74 criterion; "with_dups" option.  Certain ProofGeneral versions might
    75 support a specific search form (see ProofGeneral/CHANGES).
    76 
    77 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
    78 by default, which means that "prems" (and also "fixed variables") are
    79 suppressed from proof state output.  Note that the ProofGeneral
    80 settings mechanism allows to change and save options persistently, but
    81 older versions of Isabelle will fail to start up if a negative prems
    82 limit is imposed.
    83 
    84 * Local theory targets may be specified by non-nested blocks of
    85 ``context/locale/class ... begin'' followed by ``end''.  The body may
    86 contain definitions, theorems etc., including any derived mechanism
    87 that has been implemented on top of these primitives.  This concept
    88 generalizes the existing ``theorem (in ...)'' towards more versatility
    89 and scalability.
    90 
    91 * Proof General interface: proper undo of final 'end' command;
    92 discontinued Isabelle/classic mode (ML proof scripts).
    93 
    94 
    95 *** Document preparation ***
    96 
    97 * Added antiquotation @{theory name} which prints the given name,
    98 after checking that it refers to a valid ancestor theory in the
    99 current context.
   100 
   101 * Added antiquotations @{ML_type text} and @{ML_struct text} which
   102 check the given source text as ML type/structure, printing verbatim.
   103 
   104 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
   105 "c args == rhs" given in the current context.  (Any number of
   106 arguments may be given on the LHS.)
   107 
   108 
   109 
   110 *** Pure ***
   111 
   112 * The 'class' package offers a combination of axclass and locale to
   113 achieve Haskell-like type classes in Isabelle.  Definitions and
   114 theorems within a class context produce both relative results (with
   115 implicit parameters according to the locale context), and polymorphic
   116 constants with qualified polymorphism (according to the class
   117 context).  Within the body context of a 'class' target, a separate
   118 syntax layer ("user space type system") takes care of converting
   119 between global polymorphic consts and internal locale representation.
   120 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
   121 "isatool doc classes" provides a tutorial.
   122 
   123 * Generic code generator framework allows to generate executable
   124 code for ML and Haskell (including Isabelle classes).  A short usage
   125 sketch:
   126 
   127     internal compilation:
   128         export_code <list of constants (term syntax)> in SML
   129     writing SML code to a file:
   130         export_code <list of constants (term syntax)> in SML <filename>
   131     writing OCaml code to a file:
   132         export_code <list of constants (term syntax)> in OCaml <filename>
   133     writing Haskell code to a bunch of files:
   134         export_code <list of constants (term syntax)> in Haskell <filename>
   135 
   136     evaluating closed propositions to True/False using code generation:
   137         method ``eval''
   138 
   139 Reasonable default setup of framework in HOL.
   140 
   141 Theorem attributs for selecting and transforming function equations theorems:
   142 
   143     [code fun]:        select a theorem as function equation for a specific constant
   144     [code fun del]:    deselect a theorem as function equation for a specific constant
   145     [code inline]:     select an equation theorem for unfolding (inlining) in place
   146     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
   147 
   148 User-defined serializations (target in {SML, OCaml, Haskell}):
   149 
   150     code_const <and-list of constants (term syntax)>
   151       {(target) <and-list of const target syntax>}+
   152 
   153     code_type <and-list of type constructors>
   154       {(target) <and-list of type target syntax>}+
   155 
   156     code_instance <and-list of instances>
   157       {(target)}+
   158         where instance ::= <type constructor> :: <class>
   159 
   160     code_class <and_list of classes>
   161       {(target) <and-list of class target syntax>}+
   162         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
   163 
   164 code_instance and code_class only are effective to target Haskell.
   165 
   166 For example usage see src/HOL/ex/Codegenerator.thy and
   167 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
   168 generation from Isabelle/HOL theories is available via "isatool doc
   169 codegen".
   170 
   171 * Code generator: consts in 'consts_code' Isar commands are now
   172 referred to by usual term syntax (including optional type
   173 annotations).
   174 
   175 * Command 'no_translations' removes translation rules from theory
   176 syntax.
   177 
   178 * Overloaded definitions are now actually checked for acyclic
   179 dependencies.  The overloading scheme is slightly more general than
   180 that of Haskell98, although Isabelle does not demand an exact
   181 correspondence to type class and instance declarations.
   182 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
   183 exotic versions of overloading -- at the discretion of the user!
   184 
   185 Polymorphic constants are represented via type arguments, i.e. the
   186 instantiation that matches an instance against the most general
   187 declaration given in the signature.  For example, with the declaration
   188 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
   189 as c(nat).  Overloading is essentially simultaneous structural
   190 recursion over such type arguments.  Incomplete specification patterns
   191 impose global constraints on all occurrences, e.g. c('a * 'a) on the
   192 LHS means that more general c('a * 'b) will be disallowed on any RHS.
   193 Command 'print_theory' outputs the normalized system of recursive
   194 equations, see section "definitions".
   195 
   196 * Configuration options are maintained within the theory or proof
   197 context (with name and type bool/int/string), providing a very simple
   198 interface to a poor-man's version of general context data.  Tools may
   199 declare options in ML (e.g. using Attrib.config_int) and then refer to
   200 these values using Config.get etc.  Users may change options via an
   201 associated attribute of the same name.  This form of context
   202 declaration works particularly well with commands 'declare' or
   203 'using', for example ``declare [[foo = 42]]''.  Thus it has become
   204 very easy to avoid global references, which would not observe Isar
   205 toplevel undo/redo and fail to work with multithreading.
   206 
   207 Various global ML references of Pure and HOL have been turned into
   208 configuration options:
   209 
   210   Unify.search_bound		unify_search_bound
   211   Unify.trace_bound		unify_trace_bound
   212   Unify.trace_simp		unify_trace_simp
   213   Unify.trace_types		unify_trace_types
   214   Simplifier.simp_depth_limit	simp_depth_limit
   215   Blast.depth_limit		blast_depth_limit
   216   DatatypeProp.dtK		datatype_distinctness_limit
   217   fast_arith_neq_limit  	fast_arith_neq_limit
   218   fast_arith_split_limit	fast_arith_split_limit
   219 
   220 * Named collections of theorems may be easily installed as context
   221 data using the functor NamedThmsFun (see also
   222 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
   223 attributes; there is also a toplevel print command.  This facility is
   224 just a common case of general context data, which is the preferred way
   225 for anything more complex than just a list of facts in canonical
   226 order.
   227 
   228 * Isar: command 'declaration' augments a local theory by generic
   229 declaration functions written in ML.  This enables arbitrary content
   230 being added to the context, depending on a morphism that tells the
   231 difference of the original declaration context wrt. the application
   232 context encountered later on.
   233 
   234 * Isar: proper interfaces for simplification procedures.  Command
   235 'simproc_setup' declares named simprocs (with match patterns, and body
   236 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
   237 context.  ML antiquotation @{simproc name} retrieves named simprocs.
   238 
   239 * Isar: an extra pair of brackets around attribute declarations
   240 abbreviates a theorem reference involving an internal dummy fact,
   241 which will be ignored later --- only the effect of the attribute on
   242 the background context will persist.  This form of in-place
   243 declarations is particularly useful with commands like 'declare' and
   244 'using', for example ``have A using [[simproc a]] by simp''.
   245 
   246 * Isar: method "assumption" (and implicit closing of subproofs) now
   247 takes simple non-atomic goal assumptions into account: after applying
   248 an assumption as a rule the resulting subgoals are solved by atomic
   249 assumption steps.  This is particularly useful to finish 'obtain'
   250 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
   251 without referring to the original premise "!!x. P x ==> thesis" in the
   252 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
   253 more permissive.
   254 
   255 * Isar: implicit use of prems from the Isar proof context is
   256 considered a legacy feature.  Common applications like ``have A .''
   257 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
   258 referencing facts explicitly here improves readability and
   259 maintainability of proof texts.
   260 
   261 * Isar: improper proof element 'guess' is like 'obtain', but derives
   262 the obtained context from the course of reasoning!  For example:
   263 
   264   assume "EX x y. A x & B y"   -- "any previous fact"
   265   then guess x and y by clarify
   266 
   267 This technique is potentially adventurous, depending on the facts and
   268 proof tools being involved here.
   269 
   270 * Isar: known facts from the proof context may be specified as literal
   271 propositions, using ASCII back-quote syntax.  This works wherever
   272 named facts used to be allowed so far, in proof commands, proof
   273 methods, attributes etc.  Literal facts are retrieved from the context
   274 according to unification of type and term parameters.  For example,
   275 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
   276 theorems in the current context, then these are valid literal facts:
   277 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
   278 
   279 There is also a proof method "fact" which does the same composition
   280 for explicit goal states, e.g. the following proof texts coincide with
   281 certain special cases of literal facts:
   282 
   283   have "A" by fact                 ==  note `A`
   284   have "A ==> B" by fact           ==  note `A ==> B`
   285   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
   286   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
   287 
   288 * Isar: ":" (colon) is no longer a symbolic identifier character in
   289 outer syntax.  Thus symbolic identifiers may be used without
   290 additional white space in declarations like this: ``assume *: A''.
   291 
   292 * Isar: 'print_facts' prints all local facts of the current context,
   293 both named and unnamed ones.
   294 
   295 * Isar: 'def' now admits simultaneous definitions, e.g.:
   296 
   297   def x == "t" and y == "u"
   298 
   299 * Isar: added command 'unfolding', which is structurally similar to
   300 'using', but affects both the goal state and facts by unfolding given
   301 rewrite rules.  Thus many occurrences of the 'unfold' method or
   302 'unfolded' attribute may be replaced by first-class proof text.
   303 
   304 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
   305 and command 'unfolding' now all support object-level equalities
   306 (potentially conditional).  The underlying notion of rewrite rule is
   307 analogous to the 'rule_format' attribute, but *not* that of the
   308 Simplifier (which is usually more generous).
   309 
   310 * Isar: the new attribute [rotated n] (default n = 1) rotates the
   311 premises of a theorem by n. Useful in conjunction with drule.
   312 
   313 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
   314 method expression within a sandbox consisting of the first N
   315 sub-goals, which need to exist.  For example, ``simp_all [3]''
   316 simplifies the first three sub-goals, while (rule foo, simp_all)[]
   317 simplifies all new goals that emerge from applying rule foo to the
   318 originally first one.
   319 
   320 * Isar: schematic goals are no longer restricted to higher-order
   321 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
   322 expected.
   323 
   324 * Isar: the conclusion of a long theorem statement is now either
   325 'shows' (a simultaneous conjunction, as before), or 'obtains'
   326 (essentially a disjunction of cases with local parameters and
   327 assumptions).  The latter allows to express general elimination rules
   328 adequately; in this notation common elimination rules look like this:
   329 
   330   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
   331     assumes "EX x. P x"
   332     obtains x where "P x"
   333 
   334   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
   335     assumes "A & B"
   336     obtains A and B
   337 
   338   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
   339     assumes "A | B"
   340     obtains
   341       A
   342     | B
   343 
   344 The subsequent classical rules even refer to the formal "thesis"
   345 explicitly:
   346 
   347   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
   348     obtains "~ thesis"
   349 
   350   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
   351     obtains "thesis ==> something"
   352 
   353 The actual proof of an 'obtains' statement is analogous to that of the
   354 Isar proof element 'obtain', only that there may be several cases.
   355 Optional case names may be specified in parentheses; these will be
   356 available both in the present proof and as annotations in the
   357 resulting rule, for later use with the 'cases' method (cf. attribute
   358 case_names).
   359 
   360 * Isar: the assumptions of a long theorem statement are available as
   361 "assms" fact in the proof context.  This is more appropriate than the
   362 (historical) "prems", which refers to all assumptions of the current
   363 context, including those from the target locale, proof body etc.
   364 
   365 * Isar: 'print_statement' prints theorems from the current theory or
   366 proof context in long statement form, according to the syntax of a
   367 top-level lemma.
   368 
   369 * Isar: 'obtain' takes an optional case name for the local context
   370 introduction rule (default "that").
   371 
   372 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
   373 explicit (is "_ ==> ?foo") in the rare cases where this still happens
   374 to occur.
   375 
   376 * Pure: syntax "CONST name" produces a fully internalized constant
   377 according to the current context.  This is particularly useful for
   378 syntax translations that should refer to internal constant
   379 representations independently of name spaces.
   380 
   381 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
   382 instead of "FOO ". This allows multiple binder declarations to coexist
   383 in the same context.  INCOMPATIBILITY.
   384 
   385 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
   386 primitive that also works in a locale context (both for constants and
   387 fixed variables). Type declaration and internal syntactic representation
   388 of given constants retrieved from the context. Likewise, the
   389 'no_notation' command allows to remove given syntax annotations from the
   390 current context.
   391 
   392 * Isar/locales: new derived specification elements 'axiomatization',
   393 'definition', 'abbreviation', which support type-inference, admit
   394 object-level specifications (equality, equivalence).  See also the
   395 isar-ref manual.  Examples:
   396 
   397   axiomatization
   398     eq  (infix "===" 50) where
   399     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
   400 
   401   definition "f x y = x + y + 1"
   402   definition g where "g x = f x x"
   403 
   404   abbreviation
   405     neq  (infix "=!=" 50) where
   406     "x =!= y == ~ (x === y)"
   407 
   408 These specifications may be also used in a locale context.  Then the
   409 constants being introduced depend on certain fixed parameters, and the
   410 constant name is qualified by the locale base name.  An internal
   411 abbreviation takes care for convenient input and output, making the
   412 parameters implicit and using the original short name.  See also
   413 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
   414 entities from a monomorphic theory.
   415 
   416 Presently, abbreviations are only available 'in' a target locale, but
   417 not inherited by general import expressions.  Also note that
   418 'abbreviation' may be used as a type-safe replacement for 'syntax' +
   419 'translations' in common applications.  The "no_abbrevs" print mode
   420 prevents folding of abbreviations in term output.
   421 
   422 Concrete syntax is attached to specified constants in internal form,
   423 independently of name spaces.  The parse tree representation is
   424 slightly different -- use 'notation' instead of raw 'syntax', and
   425 'translations' with explicit "CONST" markup to accommodate this.
   426 
   427 * Pure/Isar: unified syntax for new-style specification mechanisms
   428 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
   429 full type inference and dummy patterns ("_").  For example:
   430 
   431   definition "K x _ = x"
   432 
   433   inductive conj for A B
   434   where "A ==> B ==> conj A B"
   435 
   436 * Pure: command 'print_abbrevs' prints all constant abbreviations of
   437 the current context.  Print mode "no_abbrevs" prevents inversion of
   438 abbreviations on output.
   439 
   440 * Isar/locales: improved parameter handling: use of locales "var" and
   441 "struct" no longer necessary; - parameter renamings are no longer
   442 required to be injective.  For example, this allows to define
   443 endomorphisms as locale endom = homom mult mult h.
   444 
   445 * Isar/locales: changed the way locales with predicates are defined.
   446 Instead of accumulating the specification, the imported expression is
   447 now an interpretation.  INCOMPATIBILITY: different normal form of
   448 locale expressions.  In particular, in interpretations of locales with
   449 predicates, goals repesenting already interpreted fragments are not
   450 removed automatically.  Use methods `intro_locales' and
   451 `unfold_locales'; see below.
   452 
   453 * Isar/locales: new methods `intro_locales' and `unfold_locales'
   454 provide backward reasoning on locales predicates.  The methods are
   455 aware of interpretations and discharge corresponding goals.
   456 `intro_locales' is less aggressive then `unfold_locales' and does not
   457 unfold predicates to assumptions.
   458 
   459 * Isar/locales: the order in which locale fragments are accumulated
   460 has changed.  This enables to override declarations from fragments due
   461 to interpretations -- for example, unwanted simp rules.
   462 
   463 * Isar/locales: interpretation in theories and proof contexts has been
   464 extended.  One may now specify (and prove) equations, which are
   465 unfolded in interpreted theorems.  This is useful for replacing
   466 defined concepts (constants depending on locale parameters) by
   467 concepts already existing in the target context.  Example:
   468 
   469   interpretation partial_order ["op <= :: [int, int] => bool"]
   470     where "partial_order.less (op <=) (x::int) y = (x < y)"
   471 
   472 Typically, the constant `partial_order.less' is created by a
   473 definition specification element in the context of locale
   474 partial_order.
   475 
   476 * Method "induct": improved internal context management to support
   477 local fixes and defines on-the-fly. Thus explicit meta-level
   478 connectives !!  and ==> are rarely required anymore in inductive goals
   479 (using object-logic connectives for this purpose has been long
   480 obsolete anyway). Common proof patterns are explained in
   481 src/HOL/Induct/Common_Patterns.thy, see also
   482 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
   483 examples.
   484 
   485 * Method "induct": improved handling of simultaneous goals. Instead of
   486 introducing object-level conjunction, the statement is now split into
   487 several conclusions, while the corresponding symbolic cases are nested
   488 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
   489 see src/HOL/Induct/Common_Patterns.thy, for example.
   490 
   491 * Method "induct": mutual induction rules are now specified as a list
   492 of rule sharing the same induction cases. HOL packages usually provide
   493 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
   494 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
   495 mutual induction rules differently, i.e. like this:
   496 
   497   (induct rule: foo_bar.inducts)
   498   (induct set: foo bar)
   499   (induct pred: foo bar)
   500   (induct type: foo bar)
   501 
   502 The ML function ProjectRule.projections turns old-style rules into the
   503 new format.
   504 
   505 * Method "coinduct": dual of induction, see
   506 src/HOL/Library/Coinductive_List.thy for various examples.
   507 
   508 * Method "cases", "induct", "coinduct": the ``(open)'' option is
   509 considered a legacy feature.
   510 
   511 * Attribute "symmetric" produces result with standardized schematic
   512 variables (index 0).  Potential INCOMPATIBILITY.
   513 
   514 * Simplifier: by default the simplifier trace only shows top level
   515 rewrites now. That is, trace_simp_depth_limit is set to 1 by
   516 default. Thus there is less danger of being flooded by the trace. The
   517 trace indicates where parts have been suppressed.
   518   
   519 * Provers/classical: removed obsolete classical version of elim_format
   520 attribute; classical elim/dest rules are now treated uniformly when
   521 manipulating the claset.
   522 
   523 * Provers/classical: stricter checks to ensure that supplied intro,
   524 dest and elim rules are well-formed; dest and elim rules must have at
   525 least one premise.
   526 
   527 * Provers/classical: attributes dest/elim/intro take an optional
   528 weight argument for the rule (just as the Pure versions).  Weights are
   529 ignored by automated tools, but determine the search order of single
   530 rule steps.
   531 
   532 * Syntax: input syntax now supports dummy variable binding "%_. b",
   533 where the body does not mention the bound variable.  Note that dummy
   534 patterns implicitly depend on their context of bounds, which makes
   535 "{_. _}" match any set comprehension as expected.  Potential
   536 INCOMPATIBILITY -- parse translations need to cope with syntactic
   537 constant "_idtdummy" in the binding position.
   538 
   539 * Syntax: removed obsolete syntactic constant "_K" and its associated
   540 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
   541 for example "A -> B" => "Pi A (%_. B)".
   542 
   543 * Pure: 'class_deps' command visualizes the subclass relation, using
   544 the graph browser tool.
   545 
   546 * Pure: 'print_theory' now suppresses certain internal declarations by
   547 default; use '!' option for full details.
   548 
   549 
   550 *** HOL ***
   551 
   552 * Method "metis" proves goals by applying the Metis general-purpose
   553 resolution prover (see also http://gilith.com/software/metis/).
   554 Examples are in the directory MetisExamples.  WARNING: the
   555 Isabelle/HOL-Metis integration does not yet work properly with
   556 multi-threading.
   557   
   558 * Command 'sledgehammer' invokes external automatic theorem provers as
   559 background processes.  It generates calls to the "metis" method if
   560 successful. These can be pasted into the proof.  Users do not have to
   561 wait for the automatic provers to return.  WARNING: does not really
   562 work with multi-threading.
   563 
   564 * New "auto_quickcheck" feature tests outermost goal statements for
   565 potential counter-examples.  Controlled by ML references
   566 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
   567 5000 milliseconds).  Fails silently if statements is outside of
   568 executable fragment, or any other codgenerator problem occurs.
   569 
   570 * New constant "undefined" with axiom "undefined x = undefined".
   571 
   572 * Added class "HOL.eq", allowing for code generation with polymorphic
   573 equality.
   574 
   575 * Some renaming of class constants due to canonical name prefixing in
   576 the new 'class' package:
   577 
   578     HOL.abs ~> HOL.abs_class.abs
   579     HOL.divide ~> HOL.divide_class.divide
   580     0 ~> HOL.zero_class.zero
   581     1 ~> HOL.one_class.one
   582     op + ~> HOL.plus_class.plus
   583     op - ~> HOL.minus_class.minus
   584     uminus ~> HOL.minus_class.uminus
   585     op * ~> HOL.times_class.times
   586     op < ~> HOL.ord_class.less
   587     op <= > HOL.ord_class.less_eq
   588     Nat.power ~> Power.power_class.power
   589     Nat.size ~> Nat.size_class.size
   590     Numeral.number_of ~> Numeral.number_class.number_of
   591     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
   592     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
   593     Orderings.min ~> Orderings.ord_class.min
   594     Orderings.max ~> Orderings.ord_class.max
   595     Divides.op div ~> Divides.div_class.div
   596     Divides.op mod ~> Divides.div_class.mod
   597     Divides.op dvd ~> Divides.div_class.dvd
   598 
   599 INCOMPATIBILITY.  Adaptions may be required in the following cases:
   600 
   601 a) User-defined constants using any of the names "plus", "minus",
   602 "times", "less" or "less_eq". The standard syntax translations for
   603 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
   604 names.
   605 
   606 b) Variables named "plus", "minus", "times", "less", "less_eq"
   607 INCOMPATIBILITY: use more specific names.
   608 
   609 c) Permutative equations (e.g. "a + b = b + a")
   610 Since the change of names also changes the order of terms, permutative
   611 rewrite rules may get applied in a different order. Experience shows
   612 that this is rarely the case (only two adaptions in the whole Isabelle
   613 distribution).  INCOMPATIBILITY: rewrite proofs
   614 
   615 d) ML code directly refering to constant names
   616 This in general only affects hand-written proof tactics, simprocs and
   617 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
   618 Consider using @{const_name} antiquotation.
   619 
   620 * New class "default" with associated constant "default".
   621 
   622 * Function "sgn" is now overloaded and available on int, real, complex
   623 (and other numeric types), using class "sgn".  Two possible defs of
   624 sgn are given as equational assumptions in the classes sgn_if and
   625 sgn_div_norm; ordered_idom now also inherits from sgn_if.
   626 INCOMPATIBILITY.
   627 
   628 * Locale "partial_order" now unified with class "order" (cf. theory
   629 Orderings), added parameter "less".  INCOMPATIBILITY.
   630 
   631 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
   632 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
   633 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
   634 
   635 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
   636 changed order of proof goals in instance proofs.
   637 
   638 * The transitivity reasoner for partial and linear orders is set up
   639 for classes "order" and "linorder".  Instances of the reasoner are available
   640 in all contexts importing or interpreting the corresponding locales.
   641 Method "order" invokes the reasoner separately; the reasoner
   642 is also integrated with the Simplifier as a solver.  Diagnostic
   643 command 'print_orders' shows the available instances of the reasoner
   644 in the current context.
   645 
   646 * Localized monotonicity predicate in theory "Orderings"; integrated
   647 lemmas max_of_mono and min_of_mono with this predicate.
   648 INCOMPATIBILITY.
   649 
   650 * Formulation of theorem "dense" changed slightly due to integration
   651 with new class dense_linear_order.
   652 
   653 * Uniform lattice theory development in HOL.
   654 
   655     constants "meet" and "join" now named "inf" and "sup"
   656     constant "Meet" now named "Inf"
   657 
   658     classes "meet_semilorder" and "join_semilorder" now named
   659       "lower_semilattice" and "upper_semilattice"
   660     class "lorder" now named "lattice"
   661     class "comp_lat" now named "complete_lattice"
   662 
   663     Instantiation of lattice classes allows explicit definitions
   664     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
   665 
   666   INCOMPATIBILITY.  Theorem renames:
   667 
   668     meet_left_le            ~> inf_le1
   669     meet_right_le           ~> inf_le2
   670     join_left_le            ~> sup_ge1
   671     join_right_le           ~> sup_ge2
   672     meet_join_le            ~> inf_sup_ord
   673     le_meetI                ~> le_infI
   674     join_leI                ~> le_supI
   675     le_meet                 ~> le_inf_iff
   676     le_join                 ~> ge_sup_conv
   677     meet_idempotent         ~> inf_idem
   678     join_idempotent         ~> sup_idem
   679     meet_comm               ~> inf_commute
   680     join_comm               ~> sup_commute
   681     meet_leI1               ~> le_infI1
   682     meet_leI2               ~> le_infI2
   683     le_joinI1               ~> le_supI1
   684     le_joinI2               ~> le_supI2
   685     meet_assoc              ~> inf_assoc
   686     join_assoc              ~> sup_assoc
   687     meet_left_comm          ~> inf_left_commute
   688     meet_left_idempotent    ~> inf_left_idem
   689     join_left_comm          ~> sup_left_commute
   690     join_left_idempotent    ~> sup_left_idem
   691     meet_aci                ~> inf_aci
   692     join_aci                ~> sup_aci
   693     le_def_meet             ~> le_iff_inf
   694     le_def_join             ~> le_iff_sup
   695     join_absorp2            ~> sup_absorb2
   696     join_absorp1            ~> sup_absorb1
   697     meet_absorp1            ~> inf_absorb1
   698     meet_absorp2            ~> inf_absorb2
   699     meet_join_absorp        ~> inf_sup_absorb
   700     join_meet_absorp        ~> sup_inf_absorb
   701     distrib_join_le         ~> distrib_sup_le
   702     distrib_meet_le         ~> distrib_inf_le
   703 
   704     add_meet_distrib_left   ~> add_inf_distrib_left
   705     add_join_distrib_left   ~> add_sup_distrib_left
   706     is_join_neg_meet        ~> is_join_neg_inf
   707     is_meet_neg_join        ~> is_meet_neg_sup
   708     add_meet_distrib_right  ~> add_inf_distrib_right
   709     add_join_distrib_right  ~> add_sup_distrib_right
   710     add_meet_join_distribs  ~> add_sup_inf_distribs
   711     join_eq_neg_meet        ~> sup_eq_neg_inf
   712     meet_eq_neg_join        ~> inf_eq_neg_sup
   713     add_eq_meet_join        ~> add_eq_inf_sup
   714     meet_0_imp_0            ~> inf_0_imp_0
   715     join_0_imp_0            ~> sup_0_imp_0
   716     meet_0_eq_0             ~> inf_0_eq_0
   717     join_0_eq_0             ~> sup_0_eq_0
   718     neg_meet_eq_join        ~> neg_inf_eq_sup
   719     neg_join_eq_meet        ~> neg_sup_eq_inf
   720     join_eq_if              ~> sup_eq_if
   721 
   722     mono_meet               ~> mono_inf
   723     mono_join               ~> mono_sup
   724     meet_bool_eq            ~> inf_bool_eq
   725     join_bool_eq            ~> sup_bool_eq
   726     meet_fun_eq             ~> inf_fun_eq
   727     join_fun_eq             ~> sup_fun_eq
   728     meet_set_eq             ~> inf_set_eq
   729     join_set_eq             ~> sup_set_eq
   730     meet1_iff               ~> inf1_iff
   731     meet2_iff               ~> inf2_iff
   732     meet1I                  ~> inf1I
   733     meet2I                  ~> inf2I
   734     meet1D1                 ~> inf1D1
   735     meet2D1                 ~> inf2D1
   736     meet1D2                 ~> inf1D2
   737     meet2D2                 ~> inf2D2
   738     meet1E                  ~> inf1E
   739     meet2E                  ~> inf2E
   740     join1_iff               ~> sup1_iff
   741     join2_iff               ~> sup2_iff
   742     join1I1                 ~> sup1I1
   743     join2I1                 ~> sup2I1
   744     join1I1                 ~> sup1I1
   745     join2I2                 ~> sup1I2
   746     join1CI                 ~> sup1CI
   747     join2CI                 ~> sup2CI
   748     join1E                  ~> sup1E
   749     join2E                  ~> sup2E
   750 
   751     is_meet_Meet            ~> is_meet_Inf
   752     Meet_bool_def           ~> Inf_bool_def
   753     Meet_fun_def            ~> Inf_fun_def
   754     Meet_greatest           ~> Inf_greatest
   755     Meet_lower              ~> Inf_lower
   756     Meet_set_def            ~> Inf_set_def
   757 
   758     Sup_def                 ~> Sup_Inf
   759     Sup_bool_eq             ~> Sup_bool_def
   760     Sup_fun_eq              ~> Sup_fun_def
   761     Sup_set_eq              ~> Sup_set_def
   762 
   763     listsp_meetI            ~> listsp_infI
   764     listsp_meet_eq          ~> listsp_inf_eq
   765 
   766     meet_min                ~> inf_min
   767     join_max                ~> sup_max
   768 
   769 * Added syntactic class "size"; overloaded constant "size" now has
   770 type "'a::size ==> bool"
   771 
   772 * Internal reorganisation of `size' of datatypes: size theorems
   773 "foo.size" are no longer subsumed by "foo.simps" (but are still
   774 simplification rules by default!); theorems "prod.size" now named
   775 "*.size".
   776 
   777 * Class "div" now inherits from class "times" rather than "type".
   778 INCOMPATIBILITY.
   779 
   780 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
   781 Linorder etc.  have disappeared; operations defined in terms of
   782 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
   783 
   784 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
   785 
   786 * HOL-Word: New extensive library and type for generic, fixed size
   787 machine words, with arithemtic, bit-wise, shifting and rotating
   788 operations, reflection into int, nat, and bool lists, automation for
   789 linear arithmetic (by automatic reflection into nat or int), including
   790 lemmas on overflow and monotonicity.  Instantiated to all appropriate
   791 arithmetic type classes, supporting automatic simplification of
   792 numerals on all operations.
   793 
   794 * Library/Boolean_Algebra: locales for abstract boolean algebras.
   795 
   796 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
   797 
   798 * Code generator library theories:
   799   - Code_Integer represents HOL integers by big integer literals in target
   800     languages.
   801   - Code_Char represents HOL characters by character literals in target
   802     languages.
   803   - Code_Char_chr like Code_Char, but also offers treatment of character
   804     codes; includes Code_Integer.
   805   - Executable_Set allows to generate code for finite sets using lists.
   806   - Executable_Rat implements rational numbers as triples (sign, enumerator,
   807     denominator).
   808   - Executable_Real implements a subset of real numbers, namly those
   809     representable by rational numbers.
   810   - Efficient_Nat implements natural numbers by integers, which in general will
   811     result in higher efficency; pattern matching with 0/Suc is eliminated;
   812     includes Code_Integer.
   813   - Code_Index provides an additional datatype index which is mapped to
   814     target-language built-in integers.
   815   - Code_Message provides an additional datatype message_string} which is isomorphic to
   816     strings; messages are mapped to target-language strings.
   817 
   818 * New package for inductive predicates
   819 
   820   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
   821 
   822     inductive
   823       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
   824       for z_1 :: U_1 and ... and z_n :: U_m
   825     where
   826       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
   827     | ...
   828 
   829   with full support for type-inference, rather than
   830 
   831     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
   832 
   833     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
   834     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
   835 
   836     inductive "s z_1 ... z_m"
   837     intros
   838       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
   839       ...
   840 
   841   For backward compatibility, there is a wrapper allowing inductive
   842   sets to be defined with the new package via
   843 
   844     inductive_set
   845       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
   846       for z_1 :: U_1 and ... and z_n :: U_m
   847     where
   848       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
   849     | ...
   850 
   851   or
   852 
   853     inductive_set
   854       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
   855       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
   856       for z_1 :: U_1 and ... and z_n :: U_m
   857     where
   858       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
   859     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
   860     | ...
   861 
   862   if the additional syntax "p ..." is required.
   863 
   864   Numerous examples can be found in the subdirectories src/HOL/Auth,
   865   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
   866 
   867   INCOMPATIBILITIES:
   868 
   869   - Since declaration and definition of inductive sets or predicates
   870     is no longer separated, abbreviations involving the newly
   871     introduced sets or predicates must be specified together with the
   872     introduction rules after the 'where' keyword (see above), rather
   873     than before the actual inductive definition.
   874 
   875   - The variables in induction and elimination rules are now
   876     quantified in the order of their occurrence in the introduction
   877     rules, rather than in alphabetical order. Since this may break
   878     some proofs, these proofs either have to be repaired, e.g. by
   879     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
   880     statements of the form
   881 
   882       case (rule_i a_i_1 ... a_i_{k_i})
   883 
   884     or the old order of quantification has to be restored by explicitly adding
   885     meta-level quantifiers in the introduction rules, i.e.
   886 
   887       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
   888 
   889   - The format of the elimination rules is now
   890 
   891       p z_1 ... z_m x_1 ... x_n ==>
   892         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
   893         ==> ... ==> P
   894 
   895     for predicates and
   896 
   897       (x_1, ..., x_n) : s z_1 ... z_m ==>
   898         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
   899         ==> ... ==> P
   900 
   901     for sets rather than
   902 
   903       x : s z_1 ... z_m ==>
   904         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
   905         ==> ... ==> P
   906 
   907     This may require terms in goals to be expanded to n-tuples
   908     (e.g. using case_tac or simplification with the split_paired_all
   909     rule) before the above elimination rule is applicable.
   910 
   911   - The elimination or case analysis rules for (mutually) inductive
   912     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
   913     list of rules "p_1_..._p_k.elims" is no longer available.
   914 
   915 * New package "function"/"fun" for general recursive functions,
   916 supporting mutual and nested recursion, definitions in local contexts,
   917 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
   918 for small examples, and the separate tutorial on the function
   919 package. The old recdef "package" is still available as before, but
   920 users are encouraged to use the new package.
   921 
   922 * Method "lexicographic_order" automatically synthesizes termination
   923 relations as lexicographic combinations of size measures. 
   924 
   925 * Case-expressions allow arbitrary constructor-patterns (including
   926 "_") and take their order into account, like in functional
   927 programming.  Internally, this is translated into nested
   928 case-expressions; missing cases are added and mapped to the predefined
   929 constant "undefined". In complicated cases printing may no longer show
   930 the original input but the internal form. Lambda-abstractions allow
   931 the same form of pattern matching: "% pat1 => e1 | ..." is an
   932 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
   933 variable.
   934 
   935 * IntDef: The constant "int :: nat => int" has been removed; now "int"
   936 is an abbreviation for "of_nat :: nat => int". The simplification
   937 rules for "of_nat" have been changed to work like "int" did
   938 previously.  Potential INCOMPATIBILITY:
   939   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
   940   - of_nat_diff and of_nat_mult are no longer default simp rules
   941 
   942 * Method "algebra" solves polynomial equations over (semi)rings using
   943 Groebner bases. The (semi)ring structure is defined by locales and the
   944 tool setup depends on that generic context. Installing the method for
   945 a specific type involves instantiating the locale and possibly adding
   946 declarations for computation on the coefficients.  The method is
   947 already instantiated for natural numbers and for the axiomatic class
   948 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
   949 CALCULEMUS 2007 for the general principles underlying this
   950 architecture of context-aware proof-tools.
   951 
   952 * Method "ferrack" implements quantifier elimination over
   953 special-purpose dense linear orders using locales (analogous to
   954 "algebra"). The method is already installed for class
   955 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
   956 rat, etc.
   957 
   958 * Former constant "List.op @" now named "List.append".  Use ML
   959 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
   960 circumvent possible incompatibilities when working on ML level.
   961 
   962 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
   963 
   964 * New function listsum :: 'a list => 'a for arbitrary monoids.
   965 Special syntax: "SUM x <- xs. f x" (and latex variants)
   966 
   967 * New syntax for Haskell-like list comprehension (input only), eg.
   968 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
   969 
   970 * The special syntax for function "filter" has changed from [x :
   971 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
   972 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
   973 
   974 * [a..b] is now defined for arbitrary linear orders.  It used to be
   975 defined on nat only, as an abbreviation for [a..<Suc b]
   976 INCOMPATIBILITY.
   977 
   978 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
   979 
   980 * New functions "sorted" and "sort" in src/HOL/List.thy.
   981 
   982 * New lemma collection field_simps (an extension of ring_simps) for
   983 manipulating (in)equations involving division. Multiplies with all
   984 denominators that can be proved to be non-zero (in equations) or
   985 positive/negative (in inequations).
   986 
   987 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
   988 have been improved and renamed to ring_simps, group_simps and
   989 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
   990 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
   991 
   992 * Theory Library/Commutative_Ring: switched from recdef to function
   993 package; constants add, mul, pow now curried.  Infix syntax for
   994 algebraic operations.
   995 
   996 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
   997 INCOMPATIBILITY.
   998 
   999 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  1000 INCOMPATIBILITY.
  1001 
  1002 * HOL/records: generalised field-update to take a function on the
  1003 field rather than the new value: r(|A := x|) is translated to A_update
  1004 (K x) r The K-combinator that is internally used is called K_record.
  1005 INCOMPATIBILITY: Usage of the plain update functions has to be
  1006 adapted.
  1007  
  1008 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  1009 * x = 0, which are required for a semiring.  Richer structures do not
  1010 inherit from semiring_0 anymore, because this property is a theorem
  1011 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  1012 there is more to prove, but this is mostly trivial.
  1013 
  1014 * Class "recpower" is generalized to arbitrary monoids, not just
  1015 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  1016 commutativity or semiring properties additionally.
  1017 
  1018 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  1019 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  1020 better use 'abbreviation'.
  1021 
  1022 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  1023 
  1024 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  1025 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  1026 significant changes for setting up numeral syntax for types:
  1027   - New constants Numeral.pred and Numeral.succ instead
  1028       of former Numeral.bin_pred and Numeral.bin_succ.
  1029   - Use integer operations instead of bin_add, bin_mult and so on.
  1030   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  1031   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  1032 
  1033 See src/HOL/Integ/IntArith.thy for an example setup.
  1034 
  1035 * Command 'normal_form' computes the normal form of a term that may
  1036 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  1037 produces ``[b, c, a]'' (without proof).  This command is suitable for
  1038 heavy-duty computations because the functions are compiled to ML
  1039 first.  Correspondingly, a method "normalization" is provided.  See
  1040 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  1041 
  1042 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  1043 25 like -->); output depends on the "iff" print_mode, the default is
  1044 "A = B" (with priority 50).
  1045 
  1046 * Relations less (<) and less_eq (<=) are also available on type bool.
  1047 Modified syntax to disallow nesting without explicit parentheses,
  1048 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  1049 INCOMPATIBILITY.
  1050 
  1051 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  1052 
  1053 * Relation composition operator "op O" now has precedence 75 and binds
  1054 stronger than union and intersection. INCOMPATIBILITY.
  1055 
  1056 * The old set interval syntax "{m..n(}" (and relatives) has been
  1057 removed.  Use "{m..<n}" (and relatives) instead.
  1058 
  1059 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  1060 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  1061 ``declare [[simproc del: neq]]''.
  1062 
  1063 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  1064 True/False.
  1065 
  1066 * Theorem Cons_eq_map_conv no longer declared as "simp".
  1067 
  1068 * Theorem setsum_mult renamed to setsum_right_distrib.
  1069 
  1070 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  1071 ``rule'' method.
  1072 
  1073 * Reimplemented methods "sat" and "satx", with several improvements:
  1074 goals no longer need to be stated as "<prems> ==> False", equivalences
  1075 (i.e. "=" on type bool) are handled, variable names of the form
  1076 "lit_<n>" are no longer reserved, significant speedup.
  1077 
  1078 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  1079 zChaff is still supported as well.
  1080 
  1081 * 'inductive' and 'datatype': provide projections of mutual rules,
  1082 bundled as foo_bar.inducts;
  1083 
  1084 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  1085 Library.
  1086 
  1087 * Library: moved theory Accessible_Part to main HOL.
  1088 
  1089 * Library: added theory Coinductive_List of potentially infinite lists
  1090 as greatest fixed-point.
  1091 
  1092 * Library: added theory AssocList which implements (finite) maps as
  1093 association lists.
  1094 
  1095 * Method "evaluation" solves goals (i.e. a boolean expression)
  1096 efficiently by compiling it to ML.  The goal is "proved" (via an
  1097 oracle) if it evaluates to True.
  1098 
  1099 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  1100 also when invoked by the simplifier.  This results in the Simplifier
  1101 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  1102 Configuration option fast_arith_split_limit=0 recovers the old
  1103 behavior.
  1104 
  1105 * Support for hex (0x20) and binary (0b1001) numerals.
  1106 
  1107 * New method: reify eqs (t), where eqs are equations for an
  1108 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  1109 parameter, computes a term s::'b and a list xs::'a list and proves the
  1110 theorem I xs s = t. This is also known as reification or quoting. The
  1111 resulting theorem is applied to the subgoal to substitute t with I xs
  1112 s.  If t is omitted, the subgoal itself is reified.
  1113 
  1114 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  1115 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  1116 where f is supposed to be a computable function (in the sense of code
  1117 generattion). The method uses reify to compute s and xs as above then
  1118 applies corr_thm and uses normalization by evaluation to "prove" f s =
  1119 r and finally gets the theorem t = r, which is again applied to the
  1120 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  1121 
  1122 * Reflection: Automatic reification now handels binding, an example is
  1123 available in src/HOL/ex/ReflectionEx.thy
  1124 
  1125 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  1126 command 'statespace' that is similar to 'record', but introduces an
  1127 abstract specification based on the locale infrastructure instead of
  1128 HOL types.  This leads to extra flexibility in composing state spaces,
  1129 in particular multiple inheritance and renaming of components.
  1130 
  1131 
  1132 
  1133 *** HOL-Complex ***
  1134 
  1135 * Hyperreal: Functions root and sqrt are now defined on negative real
  1136 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  1137 Nonnegativity side conditions have been removed from many lemmas, so
  1138 that more subgoals may now be solved by simplification; potential
  1139 INCOMPATIBILITY.
  1140 
  1141 * Real: new type classes formalize real normed vector spaces and
  1142 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  1143 and norm :: 'a => real.
  1144 
  1145 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  1146 reals into other types. The overloaded constant Reals :: 'a set is now
  1147 defined as range of_real; potential INCOMPATIBILITY.
  1148 
  1149 * Real: proper support for ML code generation, including 'quickcheck'.
  1150 Reals are implemented as arbitrary precision rationals.
  1151 
  1152 * Hyperreal: Several constants that previously worked only for the
  1153 reals have been generalized, so they now work over arbitrary vector
  1154 spaces. Type annotations may need to be added in some cases; potential
  1155 INCOMPATIBILITY.
  1156 
  1157   Infinitesimal  :: ('a::real_normed_vector) star set
  1158   HFinite        :: ('a::real_normed_vector) star set
  1159   HInfinite      :: ('a::real_normed_vector) star set
  1160   approx         :: ('a::real_normed_vector) star => 'a star => bool
  1161   monad          :: ('a::real_normed_vector) star => 'a star set
  1162   galaxy         :: ('a::real_normed_vector) star => 'a star set
  1163   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  1164   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  1165   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  1166   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  1167   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  1168   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  1169   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  1170   sgn            :: 'a::real_normed_vector => 'a
  1171   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  1172 
  1173 * Complex: Some complex-specific constants are now abbreviations for
  1174 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  1175 hnorm.  Other constants have been entirely removed in favor of the
  1176 polymorphic versions (INCOMPATIBILITY):
  1177 
  1178   approx        <-- capprox
  1179   HFinite       <-- CFinite
  1180   HInfinite     <-- CInfinite
  1181   Infinitesimal <-- CInfinitesimal
  1182   monad         <-- cmonad
  1183   galaxy        <-- cgalaxy
  1184   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  1185   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  1186   (ns)deriv     <-- (ns)cderiv
  1187 
  1188 
  1189 *** HOL-Algebra ***
  1190 
  1191 * Formalisation of ideals and the quotient construction over rings.
  1192 
  1193 * Order and lattice theory no longer based on records.
  1194 INCOMPATIBILITY.
  1195 
  1196 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  1197 greatest_closed.  INCOMPATIBILITY.
  1198 
  1199 * Method algebra is now set up via an attribute.  For examples see
  1200 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  1201 of algebraic structures.
  1202 
  1203 * Renamed theory CRing to Ring.
  1204 
  1205 
  1206 *** HOL-Nominal ***
  1207 
  1208 * Substantial, yet incomplete support for nominal datatypes (binding
  1209 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  1210 src/HOL/Nominal/Examples.  Prospective users should consult
  1211 http://isabelle.in.tum.de/nominal/
  1212 
  1213 
  1214 *** ML ***
  1215 
  1216 * ML basics: just one true type int, which coincides with IntInf.int
  1217 (even on SML/NJ).
  1218 
  1219 * ML within Isar: antiquotations allow to embed statically-checked
  1220 formal entities in the source, referring to the context available at
  1221 compile-time.  For example:
  1222 
  1223 ML {* @{sort "{zero,one}"} *}
  1224 ML {* @{typ "'a => 'b"} *}
  1225 ML {* @{term "%x. x"} *}
  1226 ML {* @{prop "x == y"} *}
  1227 ML {* @{ctyp "'a => 'b"} *}
  1228 ML {* @{cterm "%x. x"} *}
  1229 ML {* @{cprop "x == y"} *}
  1230 ML {* @{thm asm_rl} *}
  1231 ML {* @{thms asm_rl} *}
  1232 ML {* @{type_name c} *}
  1233 ML {* @{type_syntax c} *}
  1234 ML {* @{const_name c} *}
  1235 ML {* @{const_syntax c} *}
  1236 ML {* @{context} *}
  1237 ML {* @{theory} *}
  1238 ML {* @{theory Pure} *}
  1239 ML {* @{theory_ref} *}
  1240 ML {* @{theory_ref Pure} *}
  1241 ML {* @{simpset} *}
  1242 ML {* @{claset} *}
  1243 ML {* @{clasimpset} *}
  1244 
  1245 The same works for sources being ``used'' within an Isar context.
  1246 
  1247 * ML in Isar: improved error reporting; extra verbosity with
  1248 ML_Context.trace enabled.
  1249 
  1250 * Pure/General/table.ML: the join operations now works via exceptions
  1251 DUP/SAME instead of type option. This is simpler in simple cases, and
  1252 admits slightly more efficient complex applications.
  1253 
  1254 * Pure: 'advanced' translation functions (parse_translation etc.) now
  1255 use Context.generic instead of just theory.
  1256 
  1257 * Pure: datatype Context.generic joins theory/Proof.context and
  1258 provides some facilities for code that works in either kind of
  1259 context, notably GenericDataFun for uniform theory and proof data.
  1260 
  1261 * Pure: simplified internal attribute type, which is now always
  1262 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  1263 local (Proof.context) attributes have been discontinued, while
  1264 minimizing code duplication. Thm.rule_attribute and
  1265 Thm.declaration_attribute build canonical attributes; see also structure
  1266 Context for further operations on Context.generic, notably
  1267 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  1268 declarations and definitions.
  1269 
  1270 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  1271 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  1272 init only required for impure data. INCOMPATIBILITY: empty really need
  1273 to be empty (no dependencies on theory content!)
  1274 
  1275 * Pure/kernel: consts certification ignores sort constraints given in
  1276 signature declarations. (This information is not relevant to the
  1277 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  1278 potential INCOMPATIBILITY.
  1279 
  1280 * Pure: axiomatic type classes are now purely definitional, with
  1281 explicit proofs of class axioms and super class relations performed
  1282 internally. See Pure/axclass.ML for the main internal interfaces --
  1283 notably AxClass.define_class supercedes AxClass.add_axclass, and
  1284 AxClass.axiomatize_class/classrel/arity supersede
  1285 Sign.add_classes/classrel/arities.
  1286 
  1287 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  1288 global/local versions on theory vs. Proof.context have been
  1289 discontinued; Attrib.syntax and Method.syntax have been adapted
  1290 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  1291 attributes, methods, etc.
  1292 
  1293 * Pure: several functions of signature "... -> theory -> theory * ..."
  1294 have been reoriented to "... -> theory -> ... * theory" in order to
  1295 allow natural usage in combination with the ||>, ||>>, |-> and
  1296 fold_map combinators.
  1297 
  1298 * Pure: official theorem names (closed derivations) and additional
  1299 comments (tags) are now strictly separate.  Name hints -- which are
  1300 maintained as tags -- may be attached any time without affecting the
  1301 derivation.
  1302 
  1303 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  1304 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  1305 achieve the old behaviour.
  1306 
  1307 * Pure: the "Goal" constant is now called "prop", supporting a
  1308 slightly more general idea of ``protecting'' meta-level rule
  1309 statements.
  1310 
  1311 * Pure: Logic.(un)varify only works in a global context, which is now
  1312 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  1313 Logic.legacy_(un)varify as temporary workaround.
  1314 
  1315 * Pure: structure Name provides scalable operations for generating
  1316 internal variable names, notably Name.variants etc.  This replaces
  1317 some popular functions from term.ML:
  1318 
  1319   Term.variant		->  Name.variant
  1320   Term.variantlist	->  Name.variant_list
  1321   Term.invent_names	->  Name.invent_list
  1322 
  1323 Note that low-level renaming rarely occurs in new code -- operations
  1324 from structure Variable are used instead (see below).
  1325 
  1326 * Pure: structure Variable provides fundamental operations for proper
  1327 treatment of fixed/schematic variables in a context.  For example,
  1328 Variable.import introduces fixes for schematics of given facts and
  1329 Variable.export reverses the effect (up to renaming) -- this replaces
  1330 various freeze_thaw operations.
  1331 
  1332 * Pure: structure Goal provides simple interfaces for
  1333 init/conclude/finish and tactical prove operations (replacing former
  1334 Tactic.prove).  Goal.prove is the canonical way to prove results
  1335 within a given context; Goal.prove_global is a degraded version for
  1336 theory level goals, including a global Drule.standard.  Note that
  1337 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  1338 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  1339 in a locale context).
  1340 
  1341 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  1342 and type checking (Syntax.check_term etc.), with common combinations
  1343 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  1344 which are considered legacy and await removal.
  1345 
  1346 * Pure/Syntax: generic interfaces for type unchecking
  1347 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  1348 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  1349 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  1350 available for convenience, but refer to the very same operations using
  1351 a mere theory instead of a full context.
  1352 
  1353 * Isar: simplified treatment of user-level errors, using exception
  1354 ERROR of string uniformly.  Function error now merely raises ERROR,
  1355 without any side effect on output channels.  The Isar toplevel takes
  1356 care of proper display of ERROR exceptions.  ML code may use plain
  1357 handle/can/try; cat_error may be used to concatenate errors like this:
  1358 
  1359   ... handle ERROR msg => cat_error msg "..."
  1360 
  1361 Toplevel ML code (run directly or through the Isar toplevel) may be
  1362 embedded into the Isar toplevel with exception display/debug like
  1363 this:
  1364 
  1365   Isar.toplevel (fn () => ...)
  1366 
  1367 INCOMPATIBILITY, removed special transform_error facilities, removed
  1368 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  1369 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  1370 -- use plain ERROR instead.
  1371 
  1372 * Isar: theory setup now has type (theory -> theory), instead of a
  1373 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  1374 
  1375 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  1376 ProofContext.debug/verbose flags.
  1377 
  1378 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  1379 theory before entering a proof state.  Transactions now always see a
  1380 quasi-functional intermediate checkpoint, both in interactive and
  1381 batch mode.
  1382 
  1383 * Isar: simplified interfaces for outer syntax.  Renamed
  1384 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  1385 OuterSyntax.add_parsers -- this functionality is now included in
  1386 OuterSyntax.command etc.  INCOMPATIBILITY.
  1387 
  1388 * Simplifier: the simpset of a running simplification process now
  1389 contains a proof context (cf. Simplifier.the_context), which is the
  1390 very context that the initial simpset has been retrieved from (by
  1391 simpset_of/local_simpset_of).  Consequently, all plug-in components
  1392 (solver, looper etc.) may depend on arbitrary proof data.
  1393 
  1394 * Simplifier.inherit_context inherits the proof context (plus the
  1395 local bounds) of the current simplification process; any simproc
  1396 etc. that calls the Simplifier recursively should do this!  Removed
  1397 former Simplifier.inherit_bounds, which is already included here --
  1398 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  1399 specify an explicit context using Simplifier.context/theory_context.
  1400 
  1401 * Simplifier/Classical Reasoner: more abstract interfaces
  1402 change_simpset/claset for modifying the simpset/claset reference of a
  1403 theory; raw versions simpset/claset_ref etc. have been discontinued --
  1404 INCOMPATIBILITY.
  1405 
  1406 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  1407 "Trueprop" etc.
  1408 
  1409 
  1410 *** System ***
  1411 
  1412 * settings: ML_IDENTIFIER -- which is appended to user specific heap
  1413 locations -- now includes the Isabelle version identifier as well.
  1414 This simplifies use of multiple Isabelle installations.
  1415 
  1416 * isabelle-process: option -S (secure mode) disables some critical
  1417 operations, notably runtime compilation and evaluation of ML source
  1418 code.
  1419 
  1420 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  1421 
  1422 * Support for parallel execution, using native multicore support of
  1423 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  1424 independent theories, according to the given theory header
  1425 specifications. The maximum number of worker threads is specified via
  1426 usedir option -M or the "max-threads" setting in Proof General. A
  1427 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  1428 to 6 on a 8-core machine.  User-code needs to observe certain
  1429 guidelines for thread-safe programming, see appendix A in the Isar
  1430 Implementation manual.
  1431 
  1432 
  1433 New in Isabelle2005 (October 2005)
  1434 ----------------------------------
  1435 
  1436 *** General ***
  1437 
  1438 * Theory headers: the new header syntax for Isar theories is
  1439 
  1440   theory <name>
  1441   imports <theory1> ... <theoryN>
  1442   uses <file1> ... <fileM>
  1443   begin
  1444 
  1445 where the 'uses' part is optional.  The previous syntax
  1446 
  1447   theory <name> = <theory1> + ... + <theoryN>:
  1448 
  1449 will disappear in the next release.  Use isatool fixheaders to convert
  1450 existing theory files.  Note that there is no change in ancient
  1451 non-Isar theories now, but these will disappear soon.
  1452 
  1453 * Theory loader: parent theories can now also be referred to via
  1454 relative and absolute paths.
  1455 
  1456 * Command 'find_theorems' searches for a list of criteria instead of a
  1457 list of constants. Known criteria are: intro, elim, dest, name:string,
  1458 simp:term, and any term. Criteria can be preceded by '-' to select
  1459 theorems that do not match. Intro, elim, dest select theorems that
  1460 match the current goal, name:s selects theorems whose fully qualified
  1461 name contain s, and simp:term selects all simplification rules whose
  1462 lhs match term.  Any other term is interpreted as pattern and selects
  1463 all theorems matching the pattern. Available in ProofGeneral under
  1464 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  1465 
  1466   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  1467 
  1468 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  1469 matching the current goal as introduction rule and not having "HOL."
  1470 in their name (i.e. not being defined in theory HOL).
  1471 
  1472 * Command 'thms_containing' has been discontinued in favour of
  1473 'find_theorems'; INCOMPATIBILITY.
  1474 
  1475 * Communication with Proof General is now 8bit clean, which means that
  1476 Unicode text in UTF-8 encoding may be used within theory texts (both
  1477 formal and informal parts).  Cf. option -U of the Isabelle Proof
  1478 General interface.  Here are some simple examples (cf. src/HOL/ex):
  1479 
  1480   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  1481   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  1482 
  1483 * Improved efficiency of the Simplifier and, to a lesser degree, the
  1484 Classical Reasoner.  Typical big applications run around 2 times
  1485 faster.
  1486 
  1487 
  1488 *** Document preparation ***
  1489 
  1490 * Commands 'display_drafts' and 'print_drafts' perform simple output
  1491 of raw sources.  Only those symbols that do not require additional
  1492 LaTeX packages (depending on comments in isabellesym.sty) are
  1493 displayed properly, everything else is left verbatim.  isatool display
  1494 and isatool print are used as front ends (these are subject to the
  1495 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  1496 
  1497 * Command tags control specific markup of certain regions of text,
  1498 notably folding and hiding.  Predefined tags include "theory" (for
  1499 theory begin and end), "proof" for proof commands, and "ML" for
  1500 commands involving ML code; the additional tags "visible" and
  1501 "invisible" are unused by default.  Users may give explicit tag
  1502 specifications in the text, e.g. ''by %invisible (auto)''.  The
  1503 interpretation of tags is determined by the LaTeX job during document
  1504 preparation: see option -V of isatool usedir, or options -n and -t of
  1505 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  1506 \isadroptag.
  1507 
  1508 Several document versions may be produced at the same time via isatool
  1509 usedir (the generated index.html will link all of them).  Typical
  1510 specifications include ''-V document=theory,proof,ML'' to present
  1511 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  1512 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  1513 these parts without any formal replacement text.  The Isabelle site
  1514 default settings produce ''document'' and ''outline'' versions as
  1515 specified above.
  1516 
  1517 * Several new antiquotations:
  1518 
  1519   @{term_type term} prints a term with its type annotated;
  1520 
  1521   @{typeof term} prints the type of a term;
  1522 
  1523   @{const const} is the same as @{term const}, but checks that the
  1524   argument is a known logical constant;
  1525 
  1526   @{term_style style term} and @{thm_style style thm} print a term or
  1527   theorem applying a "style" to it
  1528 
  1529   @{ML text}
  1530 
  1531 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  1532 definitions, equations, inequations etc., 'concl' printing only the
  1533 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  1534 to print the specified premise.  TermStyle.add_style provides an ML
  1535 interface for introducing further styles.  See also the "LaTeX Sugar"
  1536 document practical applications.  The ML antiquotation prints
  1537 type-checked ML expressions verbatim.
  1538 
  1539 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  1540 and 'text' support optional locale specification '(in loc)', which
  1541 specifies the default context for interpreting antiquotations.  For
  1542 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  1543 
  1544 * Option 'locale=NAME' of antiquotations specifies an alternative
  1545 context interpreting the subsequent argument.  For example: @{thm
  1546 [locale=lattice] inf_assoc}.
  1547 
  1548 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  1549 a proof context.
  1550 
  1551 * Proper output of antiquotations for theory commands involving a
  1552 proof context (such as 'locale' or 'theorem (in loc) ...').
  1553 
  1554 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  1555 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  1556 
  1557 * isatool usedir: new option -C (default true) controls whether option
  1558 -D should include a copy of the original document directory; -C false
  1559 prevents unwanted effects such as copying of administrative CVS data.
  1560 
  1561 
  1562 *** Pure ***
  1563 
  1564 * Considerably improved version of 'constdefs' command.  Now performs
  1565 automatic type-inference of declared constants; additional support for
  1566 local structure declarations (cf. locales and HOL records), see also
  1567 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  1568 sequential dependencies of definitions within a single 'constdefs'
  1569 section; moreover, the declared name needs to be an identifier.  If
  1570 all fails, consider to fall back on 'consts' and 'defs' separately.
  1571 
  1572 * Improved indexed syntax and implicit structures.  First of all,
  1573 indexed syntax provides a notational device for subscripted
  1574 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  1575 expressions.  Secondly, in a local context with structure
  1576 declarations, number indexes \<^sub>n or the empty index (default
  1577 number 1) refer to a certain fixed variable implicitly; option
  1578 show_structs controls printing of implicit structures.  Typical
  1579 applications of these concepts involve record types and locales.
  1580 
  1581 * New command 'no_syntax' removes grammar declarations (and
  1582 translations) resulting from the given syntax specification, which is
  1583 interpreted in the same manner as for the 'syntax' command.
  1584 
  1585 * 'Advanced' translation functions (parse_translation etc.) may depend
  1586 on the signature of the theory context being presently used for
  1587 parsing/printing, see also isar-ref manual.
  1588 
  1589 * Improved 'oracle' command provides a type-safe interface to turn an
  1590 ML expression of type theory -> T -> term into a primitive rule of
  1591 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  1592 is already included here); see also FOL/ex/IffExample.thy;
  1593 INCOMPATIBILITY.
  1594 
  1595 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  1596 before); "cI" is no longer bound, use "c.intro" instead.
  1597 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  1598 axclasses vs. locales.
  1599 
  1600 * Improved internal renaming of symbolic identifiers -- attach primes
  1601 instead of base 26 numbers.
  1602 
  1603 * New flag show_question_marks controls printing of leading question
  1604 marks in schematic variable names.
  1605 
  1606 * In schematic variable names, *any* symbol following \<^isub> or
  1607 \<^isup> is now treated as part of the base name.  For example, the
  1608 following works without printing of awkward ".0" indexes:
  1609 
  1610   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  1611     by simp
  1612 
  1613 * Inner syntax includes (*(*nested*) comments*).
  1614 
  1615 * Pretty printer now supports unbreakable blocks, specified in mixfix
  1616 annotations as "(00...)".
  1617 
  1618 * Clear separation of logical types and nonterminals, where the latter
  1619 may only occur in 'syntax' specifications or type abbreviations.
  1620 Before that distinction was only partially implemented via type class
  1621 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  1622 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  1623 exotic syntax specifications may require further adaption
  1624 (e.g. Cube/Cube.thy).
  1625 
  1626 * Removed obsolete type class "logic", use the top sort {} instead.
  1627 Note that non-logical types should be declared as 'nonterminals'
  1628 rather than 'types'.  INCOMPATIBILITY for new object-logic
  1629 specifications.
  1630 
  1631 * Attributes 'induct' and 'cases': type or set names may now be
  1632 locally fixed variables as well.
  1633 
  1634 * Simplifier: can now control the depth to which conditional rewriting
  1635 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  1636 Limit.
  1637 
  1638 * Simplifier: simplification procedures may now take the current
  1639 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  1640 interface), which is very useful for calling the Simplifier
  1641 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  1642 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  1643 low-level mk_simproc no longer applies Logic.varify internally, to
  1644 allow for use in a context of fixed variables.
  1645 
  1646 * thin_tac now works even if the assumption being deleted contains !!
  1647 or ==>.  More generally, erule now works even if the major premise of
  1648 the elimination rule contains !! or ==>.
  1649 
  1650 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  1651 
  1652 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  1653 from Pure, which contains all common declarations already.  Both
  1654 theories are defined via plain Isabelle/Isar .thy files.
  1655 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  1656 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  1657 use isatool fixcpure to adapt your theory and ML sources.
  1658 
  1659 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  1660 selections of theorems in named facts via index ranges.
  1661 
  1662 * 'print_theorems': in theory mode, really print the difference
  1663 wrt. the last state (works for interactive theory development only),
  1664 in proof mode print all local facts (cf. 'print_facts');
  1665 
  1666 * 'hide': option '(open)' hides only base names.
  1667 
  1668 * More efficient treatment of intermediate checkpoints in interactive
  1669 theory development.
  1670 
  1671 * Code generator is now invoked via code_module (incremental code
  1672 generation) and code_library (modular code generation, ML structures
  1673 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  1674 must be quoted when used as identifiers.
  1675 
  1676 * New 'value' command for reading, evaluating and printing terms using
  1677 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  1678 quoted when used as identifier.
  1679 
  1680 
  1681 *** Locales ***
  1682 
  1683 * New commands for the interpretation of locale expressions in
  1684 theories (1), locales (2) and proof contexts (3).  These generate
  1685 proof obligations from the expression specification.  After the
  1686 obligations have been discharged, theorems of the expression are added
  1687 to the theory, target locale or proof context.  The synopsis of the
  1688 commands is a follows:
  1689 
  1690   (1) interpretation expr inst
  1691   (2) interpretation target < expr
  1692   (3) interpret expr inst
  1693 
  1694 Interpretation in theories and proof contexts require a parameter
  1695 instantiation of terms from the current context.  This is applied to
  1696 specifications and theorems of the interpreted expression.
  1697 Interpretation in locales only permits parameter renaming through the
  1698 locale expression.  Interpretation is smart in that interpretations
  1699 that are active already do not occur in proof obligations, neither are
  1700 instantiated theorems stored in duplicate.  Use 'print_interps' to
  1701 inspect active interpretations of a particular locale.  For details,
  1702 see the Isar Reference manual.  Examples can be found in
  1703 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  1704 
  1705 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  1706 'interpret' instead.
  1707 
  1708 * New context element 'constrains' for adding type constraints to
  1709 parameters.
  1710 
  1711 * Context expressions: renaming of parameters with syntax
  1712 redeclaration.
  1713 
  1714 * Locale declaration: 'includes' disallowed.
  1715 
  1716 * Proper static binding of attribute syntax -- i.e. types / terms /
  1717 facts mentioned as arguments are always those of the locale definition
  1718 context, independently of the context of later invocations.  Moreover,
  1719 locale operations (renaming and type / term instantiation) are applied
  1720 to attribute arguments as expected.
  1721 
  1722 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  1723 actual attributes; rare situations may require Attrib.attribute to
  1724 embed those attributes into Attrib.src that lack concrete syntax.
  1725 Attribute implementations need to cooperate properly with the static
  1726 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  1727 Attrib.XXX_thm etc. already do the right thing without further
  1728 intervention.  Only unusual applications -- such as "where" or "of"
  1729 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  1730 on the context and the facts involved -- may have to assign parsed
  1731 values to argument tokens explicitly.
  1732 
  1733 * Changed parameter management in theorem generation for long goal
  1734 statements with 'includes'.  INCOMPATIBILITY: produces a different
  1735 theorem statement in rare situations.
  1736 
  1737 * Locale inspection command 'print_locale' omits notes elements.  Use
  1738 'print_locale!' to have them included in the output.
  1739 
  1740 
  1741 *** Provers ***
  1742 
  1743 * Provers/hypsubst.ML: improved version of the subst method, for
  1744 single-step rewriting: it now works in bound variable contexts. New is
  1745 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  1746 rewrite a different subterm than the original subst method, which is
  1747 still available as 'simplesubst'.
  1748 
  1749 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  1750 and quasi orders.
  1751 
  1752 * Provers/trancl.ML: new transitivity reasoner for transitive and
  1753 reflexive-transitive closure of relations.
  1754 
  1755 * Provers/blast.ML: new reference depth_limit to make blast's depth
  1756 limit (previously hard-coded with a value of 20) user-definable.
  1757 
  1758 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  1759 is peformed already.  Object-logics merely need to finish their
  1760 initial simpset configuration as before.  INCOMPATIBILITY.
  1761 
  1762 
  1763 *** HOL ***
  1764 
  1765 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  1766 
  1767   syntax (epsilon)
  1768     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  1769 
  1770 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  1771 and x-symbol; use option '-m epsilon' to get it actually printed.
  1772 Moreover, the mathematically important symbolic identifier \<epsilon>
  1773 becomes available as variable, constant etc.  INCOMPATIBILITY,
  1774 
  1775 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  1776 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  1777 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  1778 support corresponding Isar calculations.
  1779 
  1780 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  1781 instead of ":".
  1782 
  1783 * theory SetInterval: changed the syntax for open intervals:
  1784 
  1785   Old       New
  1786   {..n(}    {..<n}
  1787   {)n..}    {n<..}
  1788   {m..n(}   {m..<n}
  1789   {)m..n}   {m<..n}
  1790   {)m..n(}  {m<..<n}
  1791 
  1792 The old syntax is still supported but will disappear in the next
  1793 release.  For conversion use the following Emacs search and replace
  1794 patterns (these are not perfect but work quite well):
  1795 
  1796   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  1797   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  1798 
  1799 * Theory Commutative_Ring (in Library): method comm_ring for proving
  1800 equalities in commutative rings; method 'algebra' provides a generic
  1801 interface.
  1802 
  1803 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  1804 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  1805 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  1806 be a tuple pattern.
  1807 
  1808 Some new syntax forms are available:
  1809 
  1810   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  1811   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  1812   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  1813   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  1814 
  1815 The latter form "\<Sum>x < k. e" used to be based on a separate
  1816 function "Summation", which has been discontinued.
  1817 
  1818 * theory Finite_Set: in structured induction proofs, the insert case
  1819 is now 'case (insert x F)' instead of the old counterintuitive 'case
  1820 (insert F x)'.
  1821 
  1822 * The 'refute' command has been extended to support a much larger
  1823 fragment of HOL, including axiomatic type classes, constdefs and
  1824 typedefs, inductive datatypes and recursion.
  1825 
  1826 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  1827 Requires zChaff with proof generation to be installed.  See
  1828 HOL/ex/SAT_Examples.thy for examples.
  1829 
  1830 * Datatype induction via method 'induct' now preserves the name of the
  1831 induction variable. For example, when proving P(xs::'a list) by
  1832 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  1833 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  1834 in unstructured proof scripts.
  1835 
  1836 * Reworked implementation of records.  Improved scalability for
  1837 records with many fields, avoiding performance problems for type
  1838 inference. Records are no longer composed of nested field types, but
  1839 of nested extension types. Therefore the record type only grows linear
  1840 in the number of extensions and not in the number of fields.  The
  1841 top-level (users) view on records is preserved.  Potential
  1842 INCOMPATIBILITY only in strange cases, where the theory depends on the
  1843 old record representation. The type generated for a record is called
  1844 <record_name>_ext_type.
  1845 
  1846 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  1847 proofs triggered by a record definition or a simproc (if
  1848 quick_and_dirty is enabled).  Definitions of large records can take
  1849 quite long.
  1850 
  1851 New simproc record_upd_simproc for simplification of multiple record
  1852 updates enabled by default.  Moreover, trivial updates are also
  1853 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  1854 occasionally, since simplification is more powerful by default.
  1855 
  1856 * typedef: proper support for polymorphic sets, which contain extra
  1857 type-variables in the term.
  1858 
  1859 * Simplifier: automatically reasons about transitivity chains
  1860 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  1861 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  1862 old proofs break occasionally as simplification may now solve more
  1863 goals than previously.
  1864 
  1865 * Simplifier: converts x <= y into x = y if assumption y <= x is
  1866 present.  Works for all partial orders (class "order"), in particular
  1867 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  1868 just like y <= x.
  1869 
  1870 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  1871 bound variable or a constant then the let is unfolded.  Otherwise
  1872 first a is simplified to b, and then f b is simplified to g. If
  1873 possible we abstract b from g arriving at "let x = b in h x",
  1874 otherwise we unfold the let and arrive at g.  The simproc can be
  1875 enabled/disabled by the reference use_let_simproc.  Potential
  1876 INCOMPATIBILITY since simplification is more powerful by default.
  1877 
  1878 * Classical reasoning: the meson method now accepts theorems as arguments.
  1879 
  1880 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  1881 jobs to provide advice on the provability of subgoals.
  1882 
  1883 * Theory OrderedGroup and Ring_and_Field: various additions and
  1884 improvements to faciliate calculations involving equalities and
  1885 inequalities.
  1886 
  1887 The following theorems have been eliminated or modified
  1888 (INCOMPATIBILITY):
  1889 
  1890   abs_eq             now named abs_of_nonneg
  1891   abs_of_ge_0        now named abs_of_nonneg
  1892   abs_minus_eq       now named abs_of_nonpos
  1893   imp_abs_id         now named abs_of_nonneg
  1894   imp_abs_neg_id     now named abs_of_nonpos
  1895   mult_pos           now named mult_pos_pos
  1896   mult_pos_le        now named mult_nonneg_nonneg
  1897   mult_pos_neg_le    now named mult_nonneg_nonpos
  1898   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  1899   mult_neg           now named mult_neg_neg
  1900   mult_neg_le        now named mult_nonpos_nonpos
  1901 
  1902 * The following lemmas in Ring_and_Field have been added to the simplifier:
  1903      
  1904      zero_le_square
  1905      not_square_less_zero 
  1906 
  1907   The following lemmas have been deleted from Real/RealPow:
  1908   
  1909      realpow_zero_zero
  1910      realpow_two
  1911      realpow_less
  1912      zero_le_power
  1913      realpow_two_le
  1914      abs_realpow_two
  1915      realpow_two_abs     
  1916 
  1917 * Theory Parity: added rules for simplifying exponents.
  1918 
  1919 * Theory List:
  1920 
  1921 The following theorems have been eliminated or modified
  1922 (INCOMPATIBILITY):
  1923 
  1924   list_all_Nil       now named list_all.simps(1)
  1925   list_all_Cons      now named list_all.simps(2)
  1926   list_all_conv      now named list_all_iff
  1927   set_mem_eq         now named mem_iff
  1928 
  1929 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  1930 asymptotic "big O" calculations.  See the notes in BigO.thy.
  1931 
  1932 
  1933 *** HOL-Complex ***
  1934 
  1935 * Theory RealDef: better support for embedding natural numbers and
  1936 integers in the reals.
  1937 
  1938 The following theorems have been eliminated or modified
  1939 (INCOMPATIBILITY):
  1940 
  1941   exp_ge_add_one_self  now requires no hypotheses
  1942   real_of_int_add      reversed direction of equality (use [symmetric])
  1943   real_of_int_minus    reversed direction of equality (use [symmetric])
  1944   real_of_int_diff     reversed direction of equality (use [symmetric])
  1945   real_of_int_mult     reversed direction of equality (use [symmetric])
  1946 
  1947 * Theory RComplete: expanded support for floor and ceiling functions.
  1948 
  1949 * Theory Ln is new, with properties of the natural logarithm
  1950 
  1951 * Hyperreal: There is a new type constructor "star" for making
  1952 nonstandard types.  The old type names are now type synonyms:
  1953 
  1954   hypreal = real star
  1955   hypnat = nat star
  1956   hcomplex = complex star
  1957 
  1958 * Hyperreal: Many groups of similarly-defined constants have been
  1959 replaced by polymorphic versions (INCOMPATIBILITY):
  1960 
  1961   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  1962 
  1963   starset      <-- starsetNat, starsetC
  1964   *s*          <-- *sNat*, *sc*
  1965   starset_n    <-- starsetNat_n, starsetC_n
  1966   *sn*         <-- *sNatn*, *scn*
  1967   InternalSets <-- InternalNatSets, InternalCSets
  1968 
  1969   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  1970   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  1971   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  1972   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  1973   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  1974 
  1975 * Hyperreal: Many type-specific theorems have been removed in favor of
  1976 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  1977 
  1978   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  1979   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  1980   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  1981   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  1982   right_minus <-- hypreal_add_minus
  1983   left_minus <-- {hypreal,hcomplex}_add_minus_left
  1984   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  1985   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  1986   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  1987   mult_1_right <-- hcomplex_mult_one_right
  1988   mult_zero_left <-- hcomplex_mult_zero_left
  1989   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  1990   right_distrib <-- hypnat_add_mult_distrib2
  1991   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  1992   right_inverse <-- hypreal_mult_inverse
  1993   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  1994   order_refl <-- {hypreal,hypnat}_le_refl
  1995   order_trans <-- {hypreal,hypnat}_le_trans
  1996   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  1997   order_less_le <-- {hypreal,hypnat}_less_le
  1998   linorder_linear <-- {hypreal,hypnat}_le_linear
  1999   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  2000   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  2001   add_nonneg_nonneg <-- hypreal_le_add_order
  2002 
  2003 * Hyperreal: Separate theorems having to do with type-specific
  2004 versions of constants have been merged into theorems that apply to the
  2005 new polymorphic constants (INCOMPATIBILITY):
  2006 
  2007   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  2008   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  2009   STAR_Un <-- {STAR,NatStar,STARC}_Un
  2010   STAR_Int <-- {STAR,NatStar,STARC}_Int
  2011   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  2012   STAR_subset <-- {STAR,NatStar,STARC}_subset
  2013   STAR_mem <-- {STAR,NatStar,STARC}_mem
  2014   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  2015   STAR_diff <-- {STAR,STARC}_diff
  2016   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  2017     STARC_hcomplex_of_complex}_image_subset
  2018   starset_n_Un <-- starset{Nat,C}_n_Un
  2019   starset_n_Int <-- starset{Nat,C}_n_Int
  2020   starset_n_Compl <-- starset{Nat,C}_n_Compl
  2021   starset_n_diff <-- starset{Nat,C}_n_diff
  2022   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  2023   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  2024   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  2025   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  2026   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  2027   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  2028   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  2029   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  2030   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  2031   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  2032   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  2033   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  2034   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  2035   starfun_diff <-- starfun{C,RC,CR}_diff
  2036   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  2037   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  2038   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  2039   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  2040   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  2041   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  2042   starfun_Id <-- starfunC_Id
  2043   starfun_approx <-- starfun{Nat,CR}_approx
  2044   starfun_capprox <-- starfun{C,RC}_capprox
  2045   starfun_abs <-- starfunNat_rabs
  2046   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  2047   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  2048   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  2049   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  2050   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  2051   starfun_add_approx <-- starfunCR_add_approx
  2052   starfun_inverse_inverse <-- starfunC_inverse_inverse
  2053   starfun_divide <-- starfun{C,CR,RC}_divide
  2054   starfun_n <-- starfun{Nat,C}_n
  2055   starfun_n_mult <-- starfun{Nat,C}_n_mult
  2056   starfun_n_add <-- starfun{Nat,C}_n_add
  2057   starfun_n_add_minus <-- starfunNat_n_add_minus
  2058   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  2059   starfun_n_minus <-- starfun{Nat,C}_n_minus
  2060   starfun_n_eq <-- starfun{Nat,C}_n_eq
  2061 
  2062   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  2063   star_n_minus <-- {hypreal,hcomplex}_minus
  2064   star_n_diff <-- {hypreal,hcomplex}_diff
  2065   star_n_mult <-- {hypreal,hcomplex}_mult
  2066   star_n_inverse <-- {hypreal,hcomplex}_inverse
  2067   star_n_le <-- {hypreal,hypnat}_le
  2068   star_n_less <-- {hypreal,hypnat}_less
  2069   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  2070   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  2071   star_n_abs <-- hypreal_hrabs
  2072   star_n_divide <-- hcomplex_divide
  2073 
  2074   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  2075   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  2076   star_of_diff <-- hypreal_of_real_diff
  2077   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  2078   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  2079   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  2080   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  2081   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  2082   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  2083   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  2084   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  2085   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  2086   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  2087   star_of_number_of <-- {hypreal,hcomplex}_number_of
  2088   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  2089   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  2090   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  2091   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  2092   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  2093   star_of_power <-- hypreal_of_real_power
  2094   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  2095 
  2096 * Hyperreal: new method "transfer" that implements the transfer
  2097 principle of nonstandard analysis. With a subgoal that mentions
  2098 nonstandard types like "'a star", the command "apply transfer"
  2099 replaces it with an equivalent one that mentions only standard types.
  2100 To be successful, all free variables must have standard types; non-
  2101 standard variables must have explicit universal quantifiers.
  2102 
  2103 * Hyperreal: A theory of Taylor series.
  2104 
  2105 
  2106 *** HOLCF ***
  2107 
  2108 * Discontinued special version of 'constdefs' (which used to support
  2109 continuous functions) in favor of the general Pure one with full
  2110 type-inference.
  2111 
  2112 * New simplification procedure for solving continuity conditions; it
  2113 is much faster on terms with many nested lambda abstractions (cubic
  2114 instead of exponential time).
  2115 
  2116 * New syntax for domain package: selector names are now optional.
  2117 Parentheses should be omitted unless argument is lazy, for example:
  2118 
  2119   domain 'a stream = cons "'a" (lazy "'a stream")
  2120 
  2121 * New command 'fixrec' for defining recursive functions with pattern
  2122 matching; defining multiple functions with mutual recursion is also
  2123 supported.  Patterns may include the constants cpair, spair, up, sinl,
  2124 sinr, or any data constructor defined by the domain package. The given
  2125 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  2126 syntax and examples.
  2127 
  2128 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  2129 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  2130 but the proof obligation additionally includes an admissibility
  2131 requirement. The packages generate instances of class cpo or pcpo,
  2132 with continuity and strictness theorems for Rep and Abs.
  2133 
  2134 * HOLCF: Many theorems have been renamed according to a more standard naming
  2135 scheme (INCOMPATIBILITY):
  2136 
  2137   foo_inject:  "foo$x = foo$y ==> x = y"
  2138   foo_eq:      "(foo$x = foo$y) = (x = y)"
  2139   foo_less:    "(foo$x << foo$y) = (x << y)"
  2140   foo_strict:  "foo$UU = UU"
  2141   foo_defined: "... ==> foo$x ~= UU"
  2142   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  2143 
  2144 
  2145 *** ZF ***
  2146 
  2147 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  2148 including the First Isomorphism Theorem (on quotienting by the kernel
  2149 of a homomorphism).
  2150 
  2151 * ZF/Simplifier: install second copy of type solver that actually
  2152 makes use of TC rules declared to Isar proof contexts (or locales);
  2153 the old version is still required for ML proof scripts.
  2154 
  2155 
  2156 *** Cube ***
  2157 
  2158 * Converted to Isar theory format; use locales instead of axiomatic
  2159 theories.
  2160 
  2161 
  2162 *** ML ***
  2163 
  2164 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  2165 for ||>, ||>>, |>>,
  2166 
  2167 * Pure/library.ML no longer defines its own option datatype, but uses
  2168 that of the SML basis, which has constructors NONE and SOME instead of
  2169 None and Some, as well as exception Option.Option instead of OPTION.
  2170 The functions the, if_none, is_some, is_none have been adapted
  2171 accordingly, while Option.map replaces apsome.
  2172 
  2173 * Pure/library.ML: the exception LIST has been given up in favour of
  2174 the standard exceptions Empty and Subscript, as well as
  2175 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  2176 superceded by the standard hd and tl functions etc.
  2177 
  2178 A number of basic list functions are no longer exported to the ML
  2179 toplevel, as they are variants of predefined functions.  The following
  2180 suggests how one can translate existing code:
  2181 
  2182     rev_append xs ys = List.revAppend (xs, ys)
  2183     nth_elem (i, xs) = List.nth (xs, i)
  2184     last_elem xs = List.last xs
  2185     flat xss = List.concat xss
  2186     seq fs = List.app fs
  2187     partition P xs = List.partition P xs
  2188     mapfilter f xs = List.mapPartial f xs
  2189 
  2190 * Pure/library.ML: several combinators for linear functional
  2191 transformations, notably reverse application and composition:
  2192 
  2193   x |> f                f #> g
  2194   (x, y) |-> f          f #-> g
  2195 
  2196 * Pure/library.ML: introduced/changed precedence of infix operators:
  2197 
  2198   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  2199   infix 2 ?;
  2200   infix 3 o oo ooo oooo;
  2201   infix 4 ~~ upto downto;
  2202 
  2203 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  2204 infix operators.
  2205 
  2206 * Pure/library.ML: natural list combinators fold, fold_rev, and
  2207 fold_map support linear functional transformations and nesting.  For
  2208 example:
  2209 
  2210   fold f [x1, ..., xN] y =
  2211     y |> f x1 |> ... |> f xN
  2212 
  2213   (fold o fold) f [xs1, ..., xsN] y =
  2214     y |> fold f xs1 |> ... |> fold f xsN
  2215 
  2216   fold f [x1, ..., xN] =
  2217     f x1 #> ... #> f xN
  2218 
  2219   (fold o fold) f [xs1, ..., xsN] =
  2220     fold f xs1 #> ... #> fold f xsN
  2221 
  2222 * Pure/library.ML: the following selectors on type 'a option are
  2223 available:
  2224 
  2225   the:               'a option -> 'a  (*partial*)
  2226   these:             'a option -> 'a  where 'a = 'b list
  2227   the_default: 'a -> 'a option -> 'a
  2228   the_list:          'a option -> 'a list
  2229 
  2230 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2231 basic operations for association lists, following natural argument
  2232 order; moreover the explicit equality predicate passed here avoids
  2233 potentially expensive polymorphic runtime equality checks.
  2234 The old functions may be expressed as follows:
  2235 
  2236   assoc = uncurry (AList.lookup (op =))
  2237   assocs = these oo AList.lookup (op =)
  2238   overwrite = uncurry (AList.update (op =)) o swap
  2239 
  2240 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2241 
  2242   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  2243   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  2244 
  2245 replacing make_keylist and keyfilter (occassionally used)
  2246 Naive rewrites:
  2247 
  2248   make_keylist = AList.make
  2249   keyfilter = AList.find (op =)
  2250 
  2251 * eq_fst and eq_snd now take explicit equality parameter, thus
  2252   avoiding eqtypes. Naive rewrites:
  2253 
  2254     eq_fst = eq_fst (op =)
  2255     eq_snd = eq_snd (op =)
  2256 
  2257 * Removed deprecated apl and apr (rarely used).
  2258   Naive rewrites:
  2259 
  2260     apl (n, op) =>>= curry op n
  2261     apr (op, m) =>>= fn n => op (n, m)
  2262 
  2263 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  2264 provides a reasonably efficient light-weight implementation of sets as
  2265 lists.
  2266 
  2267 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  2268 few new operations; existing lookup and update are now curried to
  2269 follow natural argument order (for use with fold etc.);
  2270 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  2271 
  2272 * Pure/General: output via the Isabelle channels of
  2273 writeln/warning/error etc. is now passed through Output.output, with a
  2274 hook for arbitrary transformations depending on the print_mode
  2275 (cf. Output.add_mode -- the first active mode that provides a output
  2276 function wins).  Already formatted output may be embedded into further
  2277 text via Output.raw; the result of Pretty.string_of/str_of and derived
  2278 functions (string_of_term/cterm/thm etc.) is already marked raw to
  2279 accommodate easy composition of diagnostic messages etc.  Programmers
  2280 rarely need to care about Output.output or Output.raw at all, with
  2281 some notable exceptions: Output.output is required when bypassing the
  2282 standard channels (writeln etc.), or in token translations to produce
  2283 properly formatted results; Output.raw is required when capturing
  2284 already output material that will eventually be presented to the user
  2285 a second time.  For the default print mode, both Output.output and
  2286 Output.raw have no effect.
  2287 
  2288 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  2289 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  2290 cumulative results are displayed at the end of a batch session.
  2291 
  2292 * Pure/General: File.sysify_path and File.quote_sysify path have been
  2293 replaced by File.platform_path and File.shell_path (with appropriate
  2294 hooks).  This provides a clean interface for unusual systems where the
  2295 internal and external process view of file names are different.
  2296 
  2297 * Pure: more efficient orders for basic syntactic entities: added
  2298 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  2299 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  2300 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  2301 orders now -- potential INCOMPATIBILITY for code that depends on a
  2302 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  2303 Library.sort_strings on result).
  2304 
  2305 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  2306 fold_types traverse types/terms from left to right, observing natural
  2307 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  2308 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  2309 
  2310 * Pure: name spaces have been refined, with significant changes of the
  2311 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  2312 to extern(_table).  The plain name entry path is superceded by a
  2313 general 'naming' context, which also includes the 'policy' to produce
  2314 a fully qualified name and external accesses of a fully qualified
  2315 name; NameSpace.extend is superceded by context dependent
  2316 Sign.declare_name.  Several theory and proof context operations modify
  2317 the naming context.  Especially note Theory.restore_naming and
  2318 ProofContext.restore_naming to get back to a sane state; note that
  2319 Theory.add_path is no longer sufficient to recover from
  2320 Theory.absolute_path in particular.
  2321 
  2322 * Pure: new flags short_names (default false) and unique_names
  2323 (default true) for controlling output of qualified names.  If
  2324 short_names is set, names are printed unqualified.  If unique_names is
  2325 reset, the name prefix is reduced to the minimum required to achieve
  2326 the original result when interning again, even if there is an overlap
  2327 with earlier declarations.
  2328 
  2329 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  2330 now 'extend', and 'merge' gets an additional Pretty.pp argument
  2331 (useful for printing error messages).  INCOMPATIBILITY.
  2332 
  2333 * Pure: major reorganization of the theory context.  Type Sign.sg and
  2334 Theory.theory are now identified, referring to the universal
  2335 Context.theory (see Pure/context.ML).  Actual signature and theory
  2336 content is managed as theory data.  The old code and interfaces were
  2337 spread over many files and structures; the new arrangement introduces
  2338 considerable INCOMPATIBILITY to gain more clarity:
  2339 
  2340   Context -- theory management operations (name, identity, inclusion,
  2341     parents, ancestors, merge, etc.), plus generic theory data;
  2342 
  2343   Sign -- logical signature and syntax operations (declaring consts,
  2344     types, etc.), plus certify/read for common entities;
  2345 
  2346   Theory -- logical theory operations (stating axioms, definitions,
  2347     oracles), plus a copy of logical signature operations (consts,
  2348     types, etc.); also a few basic management operations (Theory.copy,
  2349     Theory.merge, etc.)
  2350 
  2351 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  2352 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  2353 for convenience -- they merely return the theory.
  2354 
  2355 * Pure: type Type.tsig is superceded by theory in most interfaces.
  2356 
  2357 * Pure: the Isar proof context type is already defined early in Pure
  2358 as Context.proof (note that ProofContext.context and Proof.context are
  2359 aliases, where the latter is the preferred name).  This enables other
  2360 Isabelle components to refer to that type even before Isar is present.
  2361 
  2362 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  2363 typeK, constK, axiomK, oracleK), but provide explicit operations for
  2364 any of these kinds.  For example, Sign.intern typeK is now
  2365 Sign.intern_type, Theory.hide_space Sign.typeK is now
  2366 Theory.hide_types.  Also note that former
  2367 Theory.hide_classes/types/consts are now
  2368 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  2369 internalize their arguments!  INCOMPATIBILITY.
  2370 
  2371 * Pure: get_thm interface (of PureThy and ProofContext) expects
  2372 datatype thmref (with constructors Name and NameSelection) instead of
  2373 plain string -- INCOMPATIBILITY;
  2374 
  2375 * Pure: cases produced by proof methods specify options, where NONE
  2376 means to remove case bindings -- INCOMPATIBILITY in
  2377 (RAW_)METHOD_CASES.
  2378 
  2379 * Pure: the following operations retrieve axioms or theorems from a
  2380 theory node or theory hierarchy, respectively:
  2381 
  2382   Theory.axioms_of: theory -> (string * term) list
  2383   Theory.all_axioms_of: theory -> (string * term) list
  2384   PureThy.thms_of: theory -> (string * thm) list
  2385   PureThy.all_thms_of: theory -> (string * thm) list
  2386 
  2387 * Pure: print_tac now outputs the goal through the trace channel.
  2388 
  2389 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  2390 Reference Toplevel.debug (default false) controls detailed printing
  2391 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  2392 controls execution profiling -- set to 1 for time and 2 for space
  2393 (both increase the runtime).
  2394 
  2395 * Isar session: The initial use of ROOT.ML is now always timed,
  2396 i.e. the log will show the actual process times, in contrast to the
  2397 elapsed wall-clock time that the outer shell wrapper produces.
  2398 
  2399 * Simplifier: improved handling of bound variables (nameless
  2400 representation, avoid allocating new strings).  Simprocs that invoke
  2401 the Simplifier recursively should use Simplifier.inherit_bounds to
  2402 avoid local name clashes.  Failure to do so produces warnings
  2403 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  2404 for further details.
  2405 
  2406 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  2407 bindings for all theorems stored within a given theory; this may help
  2408 in porting non-Isar theories to Isar ones, while keeping ML proof
  2409 scripts for the time being.
  2410 
  2411 * ML operator HTML.with_charset specifies the charset begin used for
  2412 generated HTML files.  For example:
  2413 
  2414   HTML.with_charset "utf-8" use_thy "Hebrew";
  2415   HTML.with_charset "utf-8" use_thy "Chinese";
  2416 
  2417 
  2418 *** System ***
  2419 
  2420 * Allow symlinks to all proper Isabelle executables (Isabelle,
  2421 isabelle, isatool etc.).
  2422 
  2423 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  2424 isatool doc, isatool mkdir, display_drafts etc.).
  2425 
  2426 * isatool usedir: option -f allows specification of the ML file to be
  2427 used by Isabelle; default is ROOT.ML.
  2428 
  2429 * New isatool version outputs the version identifier of the Isabelle
  2430 distribution being used.
  2431 
  2432 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  2433 (containing Boolean satisfiability problems) into Isabelle/HOL
  2434 theories.
  2435 
  2436 
  2437 
  2438 New in Isabelle2004 (April 2004)
  2439 --------------------------------
  2440 
  2441 *** General ***
  2442 
  2443 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  2444   Replaces linorder.ML.
  2445 
  2446 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  2447   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  2448   (\<a>...\<z>), are now considered normal letters, and can therefore
  2449   be used anywhere where an ASCII letter (a...zA...Z) has until
  2450   now. COMPATIBILITY: This obviously changes the parsing of some
  2451   terms, especially where a symbol has been used as a binder, say
  2452   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  2453   as an identifier.  Fix it by inserting a space around former
  2454   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  2455   existing theory and ML files.
  2456 
  2457 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  2458 
  2459 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  2460   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  2461   a normal (but invisible) letter. For multiple letter subscripts repeat
  2462   \<^isub> like this: x\<^isub>1\<^isub>2.
  2463 
  2464 * Pure: There are now sub-/superscripts that can span more than one
  2465   character. Text between \<^bsub> and \<^esub> is set in subscript in
  2466   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  2467   superscript. The new control characters are not identifier parts.
  2468 
  2469 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  2470   content of "..." to the latex file instead of \isacntrl... . The "..."
  2471   may consist of any printable characters excluding the end bracket >.
  2472 
  2473 * Pure: Using new Isar command "finalconsts" (or the ML functions
  2474   Theory.add_finals or Theory.add_finals_i) it is now possible to
  2475   declare constants "final", which prevents their being given a definition
  2476   later.  It is useful for constants whose behaviour is fixed axiomatically
  2477   rather than definitionally, such as the meta-logic connectives.
  2478 
  2479 * Pure: 'instance' now handles general arities with general sorts
  2480   (i.e. intersections of classes),
  2481 
  2482 * Presentation: generated HTML now uses a CSS style sheet to make layout
  2483   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  2484   It can be changed to alter the colors/layout of generated pages.
  2485 
  2486 
  2487 *** Isar ***
  2488 
  2489 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  2490   cut_tac, subgoal_tac and thin_tac:
  2491   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  2492     locales are no longer forced to write Isar proof scripts.
  2493     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  2494     emulations.
  2495   - INCOMPATIBILITY: names of variables to be instantiated may no
  2496     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  2497     This is consistent with the instantiation attribute "where".
  2498 
  2499 * Attributes "where" and "of":
  2500   - Now take type variables of instantiated theorem into account when reading
  2501     the instantiation string.  This fixes a bug that caused instantiated
  2502     theorems to have too special types in some circumstances.
  2503   - "where" permits explicit instantiations of type variables.
  2504 
  2505 * Calculation commands "moreover" and "also" no longer interfere with
  2506   current facts ("this"), admitting arbitrary combinations with "then"
  2507   and derived forms.
  2508 
  2509 * Locales:
  2510   - Goal statements involving the context element "includes" no longer
  2511     generate theorems with internal delta predicates (those ending on
  2512     "_axioms") in the premise.
  2513     Resolve particular premise with <locale>.intro to obtain old form.
  2514   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  2515     specification and "includes" elements in goal statement.
  2516   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  2517     [intro?] and [elim?] (respectively) by default.
  2518   - Experimental command for instantiation of locales in proof contexts:
  2519         instantiate <label>[<attrs>]: <loc>
  2520     Instantiates locale <loc> and adds all its theorems to the current context
  2521     taking into account their attributes.  Label and attrs are optional
  2522     modifiers, like in theorem declarations.  If present, names of
  2523     instantiated theorems are qualified with <label>, and the attributes
  2524     <attrs> are applied after any attributes these theorems might have already.
  2525       If the locale has assumptions, a chained fact of the form
  2526     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  2527     are derived.  The command does not support old-style locales declared
  2528     with "locale (open)".
  2529       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  2530 
  2531 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  2532   (Isar) contexts.
  2533 
  2534 
  2535 *** HOL ***
  2536 
  2537 * Proof import: new image HOL4 contains the imported library from
  2538   the HOL4 system with about 2500 theorems. It is imported by
  2539   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  2540   can be used like any other Isabelle image.  See
  2541   HOL/Import/HOL/README for more information.
  2542 
  2543 * Simplifier:
  2544   - Much improved handling of linear and partial orders.
  2545     Reasoners for linear and partial orders are set up for type classes
  2546     "linorder" and "order" respectively, and are added to the default simpset
  2547     as solvers.  This means that the simplifier can build transitivity chains
  2548     to solve goals from the assumptions.
  2549   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  2550     of blast or auto after simplification become unnecessary because the goal
  2551     is solved by simplification already.
  2552 
  2553 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  2554     all proved in axiomatic type classes for semirings, rings and fields.
  2555 
  2556 * Numerics:
  2557   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  2558     now formalized using the Ring_and_Field theory mentioned above.
  2559   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  2560     than before, because now they are set up once in a generic manner.
  2561   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  2562     Look for the general versions in Ring_and_Field (and Power if they concern
  2563     exponentiation).
  2564 
  2565 * Type "rat" of the rational numbers is now available in HOL-Complex.
  2566 
  2567 * Records:
  2568   - Record types are now by default printed with their type abbreviation
  2569     instead of the list of all field types. This can be configured via
  2570     the reference "print_record_type_abbr".
  2571   - Simproc "record_upd_simproc" for simplification of multiple updates added
  2572     (not enabled by default).
  2573   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  2574     EX x. x = sel r to True (not enabled by default).
  2575   - Tactic "record_split_simp_tac" to split and simplify records added.
  2576 
  2577 * 'specification' command added, allowing for definition by
  2578   specification.  There is also an 'ax_specification' command that
  2579   introduces the new constants axiomatically.
  2580 
  2581 * arith(_tac) is now able to generate counterexamples for reals as well.
  2582 
  2583 * HOL-Algebra: new locale "ring" for non-commutative rings.
  2584 
  2585 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  2586   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  2587 
  2588 * HOL-Matrix: a first theory for matrices in HOL with an application of
  2589   matrix theory to linear programming.
  2590 
  2591 * Unions and Intersections:
  2592   The latex output syntax of UN and INT has been changed
  2593   from "\Union x \in A. B" to "\Union_{x \in A} B"
  2594   i.e. the index formulae has become a subscript.
  2595   Similarly for "\Union x. B", and for \Inter instead of \Union.
  2596 
  2597 * Unions and Intersections over Intervals:
  2598   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  2599   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  2600   like in normal math, and corresponding versions for < and for intersection.
  2601 
  2602 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  2603   lexicographic dictonary ordering has been added as "lexord".
  2604 
  2605 * ML: the legacy theory structures Int and List have been removed. They had
  2606   conflicted with ML Basis Library structures having the same names.
  2607 
  2608 * 'refute' command added to search for (finite) countermodels.  Only works
  2609   for a fragment of HOL.  The installation of an external SAT solver is
  2610   highly recommended.  See "HOL/Refute.thy" for details.
  2611 
  2612 * 'quickcheck' command: Allows to find counterexamples by evaluating
  2613   formulae under an assignment of free variables to random values.
  2614   In contrast to 'refute', it can deal with inductive datatypes,
  2615   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  2616   for examples.
  2617 
  2618 
  2619 *** HOLCF ***
  2620 
  2621 * Streams now come with concatenation and are part of the HOLCF image
  2622 
  2623 
  2624 
  2625 New in Isabelle2003 (May 2003)
  2626 ------------------------------
  2627 
  2628 *** General ***
  2629 
  2630 * Provers/simplifier:
  2631 
  2632   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  2633     Assumptions are now subject to complete mutual simplification,
  2634     not just from left to right. The simplifier now preserves
  2635     the order of assumptions.
  2636 
  2637     Potential INCOMPATIBILITY:
  2638 
  2639     -- simp sometimes diverges where the old version did
  2640        not, e.g. invoking simp on the goal
  2641 
  2642         [| P (f x); y = x; f x = f y |] ==> Q
  2643 
  2644        now gives rise to the infinite reduction sequence
  2645 
  2646         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  2647 
  2648        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  2649        kind of problem.
  2650 
  2651     -- Tactics combining classical reasoner and simplification (such as auto)
  2652        are also affected by this change, because many of them rely on
  2653        simp. They may sometimes diverge as well or yield a different numbers
  2654        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  2655        in case of problems. Sometimes subsequent calls to the classical
  2656        reasoner will fail because a preceeding call to the simplifier too
  2657        eagerly simplified the goal, e.g. deleted redundant premises.
  2658 
  2659   - The simplifier trace now shows the names of the applied rewrite rules
  2660 
  2661   - You can limit the number of recursive invocations of the simplifier
  2662     during conditional rewriting (where the simplifie tries to solve the
  2663     conditions before applying the rewrite rule):
  2664     ML "simp_depth_limit := n"
  2665     where n is an integer. Thus you can force termination where previously
  2666     the simplifier would diverge.
  2667 
  2668   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  2669 
  2670   - No longer aborts on failed congruence proof.  Instead, the
  2671     congruence is ignored.
  2672 
  2673 * Pure: New generic framework for extracting programs from constructive
  2674   proofs. See HOL/Extraction.thy for an example instantiation, as well
  2675   as HOL/Extraction for some case studies.
  2676 
  2677 * Pure: The main goal of the proof state is no longer shown by default, only
  2678 the subgoals. This behaviour is controlled by a new flag.
  2679    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  2680 (ML: Proof.show_main_goal).
  2681 
  2682 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  2683 rules whose conclusion matches subgoal 1:
  2684       PG menu: Isabelle/Isar -> Show me -> matching rules
  2685 The rules are ordered by how closely they match the subgoal.
  2686 In particular, rules that solve a subgoal outright are displayed first
  2687 (or rather last, the way they are printed).
  2688 (ML: ProofGeneral.print_intros())
  2689 
  2690 * Pure: New flag trace_unify_fail causes unification to print
  2691 diagnostic information (PG: in trace buffer) when it fails. This is
  2692 useful for figuring out why single step proofs like rule, erule or
  2693 assumption failed.
  2694 
  2695 * Pure: Locale specifications now produce predicate definitions
  2696 according to the body of text (covering assumptions modulo local
  2697 definitions); predicate "loc_axioms" covers newly introduced text,
  2698 while "loc" is cumulative wrt. all included locale expressions; the
  2699 latter view is presented only on export into the global theory
  2700 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  2701 on the old view without predicates;
  2702 
  2703 * Pure: predefined locales "var" and "struct" are useful for sharing
  2704 parameters (as in CASL, for example); just specify something like
  2705 ``var x + var y + struct M'' as import;
  2706 
  2707 * Pure: improved thms_containing: proper indexing of facts instead of
  2708 raw theorems; check validity of results wrt. current name space;
  2709 include local facts of proof configuration (also covers active
  2710 locales), cover fixed variables in index; may use "_" in term
  2711 specification; an optional limit for the number of printed facts may
  2712 be given (the default is 40);
  2713 
  2714 * Pure: disallow duplicate fact bindings within new-style theory files
  2715 (batch-mode only);
  2716 
  2717 * Provers: improved induct method: assumptions introduced by case
  2718 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  2719 the goal statement); "foo" still refers to all facts collectively;
  2720 
  2721 * Provers: the function blast.overloaded has been removed: all constants
  2722 are regarded as potentially overloaded, which improves robustness in exchange
  2723 for slight decrease in efficiency;
  2724 
  2725 * Provers/linorder: New generic prover for transitivity reasoning over
  2726 linear orders.  Note: this prover is not efficient!
  2727 
  2728 * Isar: preview of problems to finish 'show' now produce an error
  2729 rather than just a warning (in interactive mode);
  2730 
  2731 
  2732 *** HOL ***
  2733 
  2734 * arith(_tac)
  2735 
  2736  - Produces a counter example if it cannot prove a goal.
  2737    Note that the counter example may be spurious if the goal is not a formula
  2738    of quantifier-free linear arithmetic.
  2739    In ProofGeneral the counter example appears in the trace buffer.
  2740 
  2741  - Knows about div k and mod k where k is a numeral of type nat or int.
  2742 
  2743  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  2744    linear arithmetic fails. This takes account of quantifiers and divisibility.
  2745    Presburger arithmetic can also be called explicitly via presburger(_tac).
  2746 
  2747 * simp's arithmetic capabilities have been enhanced a bit: it now
  2748 takes ~= in premises into account (by performing a case split);
  2749 
  2750 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  2751 are distributed over a sum of terms;
  2752 
  2753 * New tactic "trans_tac" and method "trans" instantiate
  2754 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  2755 "<=", "<" and "=").
  2756 
  2757 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  2758 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  2759 
  2760 * 'typedef' command has new option "open" to suppress the set
  2761 definition;
  2762 
  2763 * functions Min and Max on finite sets have been introduced (theory
  2764 Finite_Set);
  2765 
  2766 * attribute [symmetric] now works for relations as well; it turns
  2767 (x,y) : R^-1 into (y,x) : R, and vice versa;
  2768 
  2769 * induct over a !!-quantified statement (say !!x1..xn):
  2770   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  2771 
  2772 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  2773 %x. None. Warning: empty_def now refers to the previously hidden definition
  2774 of the empty set.
  2775 
  2776 * Algebra: formalization of classical algebra.  Intended as base for
  2777 any algebraic development in Isabelle.  Currently covers group theory
  2778 (up to Sylow's theorem) and ring theory (Universal Property of
  2779 Univariate Polynomials).  Contributions welcome;
  2780 
  2781 * GroupTheory: deleted, since its material has been moved to Algebra;
  2782 
  2783 * Complex: new directory of the complex numbers with numeric constants,
  2784 nonstandard complex numbers, and some complex analysis, standard and
  2785 nonstandard (Jacques Fleuriot);
  2786 
  2787 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  2788 
  2789 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  2790 Fleuriot);
  2791 
  2792 * Real/HahnBanach: updated and adapted to locales;
  2793 
  2794 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  2795 Gray and Kramer);
  2796 
  2797 * UNITY: added the Meier-Sanders theory of progress sets;
  2798 
  2799 * MicroJava: bytecode verifier and lightweight bytecode verifier
  2800 as abstract algorithms, instantiated to the JVM;
  2801 
  2802 * Bali: Java source language formalization. Type system, operational
  2803 semantics, axiomatic semantics. Supported language features:
  2804 classes, interfaces, objects,virtual methods, static methods,
  2805 static/instance fields, arrays, access modifiers, definite
  2806 assignment, exceptions.
  2807 
  2808 
  2809 *** ZF ***
  2810 
  2811 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  2812 universe, etc.);
  2813 
  2814 * Main ZF: virtually all theories converted to new-style format;
  2815 
  2816 
  2817 *** ML ***
  2818 
  2819 * Pure: Tactic.prove provides sane interface for internal proofs;
  2820 omits the infamous "standard" operation, so this is more appropriate
  2821 than prove_goalw_cterm in many situations (e.g. in simprocs);
  2822 
  2823 * Pure: improved error reporting of simprocs;
  2824 
  2825 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  2826 up simprocs;
  2827 
  2828 
  2829 *** Document preparation ***
  2830 
  2831 * uses \par instead of \\ for line breaks in theory text. This may
  2832 shift some page breaks in large documents. To get the old behaviour
  2833 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  2834 
  2835 * minimized dependencies of isabelle.sty and isabellesym.sty on
  2836 other packages
  2837 
  2838 * \<euro> now needs package babel/greek instead of marvosym (which
  2839 broke \Rightarrow)
  2840 
  2841 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  2842 textcomp package)
  2843 
  2844 
  2845 
  2846 New in Isabelle2002 (March 2002)
  2847 --------------------------------
  2848 
  2849 *** Document preparation ***
  2850 
  2851 * greatly simplified document preparation setup, including more
  2852 graceful interpretation of isatool usedir -i/-d/-D options, and more
  2853 instructive isatool mkdir; users should basically be able to get
  2854 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  2855 users may run a separate document processing stage manually like this:
  2856 "isatool usedir -D output HOL Test && isatool document Test/output";
  2857 
  2858 * theory dependency graph may now be incorporated into documents;
  2859 isatool usedir -g true will produce session_graph.eps/.pdf for use
  2860 with \includegraphics of LaTeX;
  2861 
  2862 * proper spacing of consecutive markup elements, especially text
  2863 blocks after section headings;
  2864 
  2865 * support bold style (for single symbols only), input syntax is like
  2866 this: "\<^bold>\<alpha>" or "\<^bold>A";
  2867 
  2868 * \<bullet> is now output as bold \cdot by default, which looks much
  2869 better in printed text;
  2870 
  2871 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  2872 note that these symbols are currently unavailable in Proof General /
  2873 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  2874 
  2875 * isatool latex no longer depends on changed TEXINPUTS, instead
  2876 isatool document copies the Isabelle style files to the target
  2877 location;
  2878 
  2879 
  2880 *** Isar ***
  2881 
  2882 * Pure/Provers: improved proof by cases and induction;
  2883   - 'case' command admits impromptu naming of parameters (such as
  2884     "case (Suc n)");
  2885   - 'induct' method divinates rule instantiation from the inductive
  2886     claim; no longer requires excessive ?P bindings for proper
  2887     instantiation of cases;
  2888   - 'induct' method properly enumerates all possibilities of set/type
  2889     rules; as a consequence facts may be also passed through *type*
  2890     rules without further ado;
  2891   - 'induct' method now derives symbolic cases from the *rulified*
  2892     rule (before it used to rulify cases stemming from the internal
  2893     atomized version); this means that the context of a non-atomic
  2894     statement becomes is included in the hypothesis, avoiding the
  2895     slightly cumbersome show "PROP ?case" form;
  2896   - 'induct' may now use elim-style induction rules without chaining
  2897     facts, using ``missing'' premises from the goal state; this allows
  2898     rules stemming from inductive sets to be applied in unstructured
  2899     scripts, while still benefitting from proper handling of non-atomic
  2900     statements; NB: major inductive premises need to be put first, all
  2901     the rest of the goal is passed through the induction;
  2902   - 'induct' proper support for mutual induction involving non-atomic
  2903     rule statements (uses the new concept of simultaneous goals, see
  2904     below);
  2905   - append all possible rule selections, but only use the first
  2906     success (no backtracking);
  2907   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  2908   - undeclared rule case names default to numbers 1, 2, 3, ...;
  2909   - added 'print_induct_rules' (covered by help item in recent Proof
  2910     General versions);
  2911   - moved induct/cases attributes to Pure, methods to Provers;
  2912   - generic method setup instantiated for FOL and HOL;
  2913 
  2914 * Pure: support multiple simultaneous goal statements, for example
  2915 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  2916 meta-level mechanism, this acts as if several individual goals had
  2917 been stated separately; in particular common proof methods need to be
  2918 repeated in order to cover all claims; note that a single elimination
  2919 step is *not* sufficient to establish the two conjunctions, so this
  2920 fails:
  2921 
  2922   assume "A & B" then have A and B ..   (*".." fails*)
  2923 
  2924 better use "obtain" in situations as above; alternative refer to
  2925 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  2926 
  2927 * Pure: proper integration with ``locales''; unlike the original
  2928 version by Florian Kammller, Isar locales package high-level proof
  2929 contexts rather than raw logical ones (e.g. we admit to include
  2930 attributes everywhere); operations on locales include merge and
  2931 rename; support for implicit arguments (``structures''); simultaneous
  2932 type-inference over imports and text; see also HOL/ex/Locales.thy for
  2933 some examples;
  2934 
  2935 * Pure: the following commands have been ``localized'', supporting a
  2936 target locale specification "(in name)": 'lemma', 'theorem',
  2937 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  2938 stored both within the locale and at the theory level (exported and
  2939 qualified by the locale name);
  2940 
  2941 * Pure: theory goals may now be specified in ``long'' form, with
  2942 ad-hoc contexts consisting of arbitrary locale elements. for example
  2943 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  2944 definitions may be given, too); the result is a meta-level rule with
  2945 the context elements being discharged in the obvious way;
  2946 
  2947 * Pure: new proof command 'using' allows to augment currently used
  2948 facts after a goal statement ('using' is syntactically analogous to
  2949 'apply', but acts on the goal's facts only); this allows chained facts
  2950 to be separated into parts given before and after a claim, as in
  2951 ``from a and b have C using d and e <proof>'';
  2952 
  2953 * Pure: renamed "antecedent" case to "rule_context";
  2954 
  2955 * Pure: new 'judgment' command records explicit information about the
  2956 object-logic embedding (used by several tools internally); no longer
  2957 use hard-wired "Trueprop";
  2958 
  2959 * Pure: added 'corollary' command;
  2960 
  2961 * Pure: fixed 'token_translation' command;
  2962 
  2963 * Pure: removed obsolete 'exported' attribute;
  2964 
  2965 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  2966 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  2967 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  2968 
  2969 * Pure: method 'atomize' presents local goal premises as object-level
  2970 statements (atomic meta-level propositions); setup controlled via
  2971 rewrite rules declarations of 'atomize' attribute; example
  2972 application: 'induct' method with proper rule statements in improper
  2973 proof *scripts*;
  2974 
  2975 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  2976 now consider the syntactic context of assumptions, giving a better
  2977 chance to get type-inference of the arguments right (this is
  2978 especially important for locales);
  2979 
  2980 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  2981 mode;
  2982 
  2983 * Pure/obtain: the formal conclusion "thesis", being marked as
  2984 ``internal'', may no longer be reference directly in the text;
  2985 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  2986 situations;
  2987 
  2988 * Pure: generic 'sym' attribute which declares a rule both as pure
  2989 'elim?' and for the 'symmetric' operation;
  2990 
  2991 * Pure: marginal comments ``--'' may now occur just anywhere in the
  2992 text; the fixed correlation with particular command syntax has been
  2993 discontinued;
  2994 
  2995 * Pure: new method 'rules' is particularly well-suited for proof
  2996 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  2997 but often produces more compact proof terms with less detours;
  2998 
  2999 * Pure/Provers/classical: simplified integration with pure rule
  3000 attributes and methods; the classical "intro?/elim?/dest?"
  3001 declarations coincide with the pure ones; the "rule" method no longer
  3002 includes classically swapped intros; "intro" and "elim" methods no
  3003 longer pick rules from the context; also got rid of ML declarations
  3004 AddXIs/AddXEs/AddXDs; all of this has some potential for
  3005 INCOMPATIBILITY;
  3006 
  3007 * Provers/classical: attribute 'swapped' produces classical inversions
  3008 of introduction rules;
  3009 
  3010 * Provers/simplifier: 'simplified' attribute may refer to explicit
  3011 rules instead of full simplifier context; 'iff' attribute handles
  3012 conditional rules;
  3013 
  3014 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  3015 
  3016 * HOL: 'recdef' now fails on unfinished automated proofs, use
  3017 "(permissive)" option to recover old behavior;
  3018 
  3019 * HOL: 'inductive' no longer features separate (collective) attributes
  3020 for 'intros' (was found too confusing);
  3021 
  3022 * HOL: properly declared induction rules less_induct and
  3023 wf_induct_rule;
  3024 
  3025 
  3026 *** HOL ***
  3027 
  3028 * HOL: moved over to sane numeral syntax; the new policy is as
  3029 follows:
  3030 
  3031   - 0 and 1 are polymorphic constants, which are defined on any
  3032   numeric type (nat, int, real etc.);
  3033 
  3034   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  3035   binary representation internally;
  3036 
  3037   - type nat has special constructor Suc, and generally prefers Suc 0
  3038   over 1::nat and Suc (Suc 0) over 2::nat;
  3039 
  3040 This change may cause significant problems of INCOMPATIBILITY; here
  3041 are some hints on converting existing sources:
  3042 
  3043   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  3044   entities, so expressions involving "-" (unary or binary minus) need
  3045   to be spaced properly;
  3046 
  3047   - existing occurrences of "1" may need to be constraint "1::nat" or
  3048   even replaced by Suc 0; similar for old "2";
  3049 
  3050   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  3051 
  3052   - remove all special provisions on numerals in proofs;
  3053 
  3054 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  3055 representation (depends on bin_arith_simps in the default context);
  3056 
  3057 * HOL: symbolic syntax for x^2 (numeral 2);
  3058 
  3059 * HOL: the class of all HOL types is now called "type" rather than
  3060 "term"; INCOMPATIBILITY, need to adapt references to this type class
  3061 in axclass/classes, instance/arities, and (usually rare) occurrences
  3062 in typings (of consts etc.); internally the class is called
  3063 "HOL.type", ML programs should refer to HOLogic.typeS;
  3064 
  3065 * HOL/record package improvements:
  3066   - new derived operations "fields" to build a partial record section,
  3067     "extend" to promote a fixed record to a record scheme, and
  3068     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  3069     declared as simp by default;
  3070   - shared operations ("more", "fields", etc.) now need to be always
  3071     qualified) --- potential INCOMPATIBILITY;
  3072   - removed "make_scheme" operations (use "make" with "extend") --
  3073     INCOMPATIBILITY;
  3074   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  3075   - provides cases/induct rules for use with corresponding Isar
  3076     methods (for concrete records, record schemes, concrete more
  3077     parts, and schematic more parts -- in that order);
  3078   - internal definitions directly based on a light-weight abstract
  3079     theory of product types over typedef rather than datatype;
  3080 
  3081 * HOL: generic code generator for generating executable ML code from
  3082 specifications; specific support for HOL constructs such as inductive
  3083 datatypes and sets, as well as recursive functions; can be invoked
  3084 via 'generate_code' theory section;
  3085 
  3086 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  3087 
  3088 * HOL: consolidated and renamed several theories.  In particular:
  3089         Ord.thy has been absorbed into HOL.thy
  3090         String.thy has been absorbed into List.thy
  3091 
  3092 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  3093 (beware of argument permutation!);
  3094 
  3095 * HOL: linorder_less_split superseded by linorder_cases;
  3096 
  3097 * HOL/List: "nodups" renamed to "distinct";
  3098 
  3099 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  3100 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  3101   - Ex_def has changed, now need to use some_eq_ex
  3102 
  3103 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  3104 in this (rare) case use:
  3105 
  3106   delSWrapper "split_all_tac"
  3107   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  3108 
  3109 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  3110 MAY FAIL;
  3111 
  3112 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  3113 Isabelle's type classes, ^ on functions and relations has too general
  3114 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  3115 necessary to attach explicit type constraints;
  3116 
  3117 * HOL/Relation: the prefix name of the infix "O" has been changed from
  3118 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  3119 renamed accordingly (eg "compI" -> "rel_compI").
  3120 
  3121 * HOL: syntax translations now work properly with numerals and records
  3122 expressions;
  3123 
  3124 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  3125 of "lam" -- INCOMPATIBILITY;
  3126 
  3127 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  3128 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  3129 renamed "Product_Type.unit";
  3130 
  3131 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  3132 
  3133 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  3134 the "cases" method);
  3135 
  3136 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  3137 Florian Kammller);
  3138 
  3139 * HOL/IMP: updated and converted to new-style theory format; several
  3140 parts turned into readable document, with proper Isar proof texts and
  3141 some explanations (by Gerwin Klein);
  3142 
  3143 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  3144 
  3145 * HOL-Hyperreal is now a logic image;
  3146 
  3147 
  3148 *** HOLCF ***
  3149 
  3150 * Isar: consts/constdefs supports mixfix syntax for continuous
  3151 operations;
  3152 
  3153 * Isar: domain package adapted to new-style theory format, e.g. see
  3154 HOLCF/ex/Dnat.thy;
  3155 
  3156 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  3157 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  3158 lift.induct_tac, always use UU instead of Undef;
  3159 
  3160 * HOLCF/IMP: updated and converted to new-style theory;
  3161 
  3162 
  3163 *** ZF ***
  3164 
  3165 * Isar: proper integration of logic-specific tools and packages,
  3166 including theory commands '(co)inductive', '(co)datatype',
  3167 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  3168 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  3169 
  3170 * theory Main no longer includes AC; for the Axiom of Choice, base
  3171 your theory on Main_ZFC;
  3172 
  3173 * the integer library now covers quotients and remainders, with many
  3174 laws relating division to addition, multiplication, etc.;
  3175 
  3176 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  3177 typeless version of the formalism;
  3178 
  3179 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  3180 format;
  3181 
  3182 * ZF/Induct: new directory for examples of inductive definitions,
  3183 including theory Multiset for multiset orderings; converted to
  3184 new-style theory format;
  3185 
  3186 * ZF: many new theorems about lists, ordinals, etc.;
  3187 
  3188 
  3189 *** General ***
  3190 
  3191 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  3192 variable proof controls level of detail: 0 = no proofs (only oracle
  3193 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  3194 also ref manual for further ML interfaces;
  3195 
  3196 * Pure/axclass: removed obsolete ML interface
  3197 goal_subclass/goal_arity;
  3198 
  3199 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  3200 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  3201 separate tokens, so expressions involving minus need to be spaced
  3202 properly;
  3203 
  3204 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  3205 rather than "infixl" or "infixr";
  3206 
  3207 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  3208 sort constraint specifications in type inference; e.g. "x::_::foo"
  3209 ensures that the type of "x" is of sort "foo" (but not necessarily a
  3210 type variable);
  3211 
  3212 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  3213 control output of nested => (types); the default behavior is
  3214 "type_brackets";
  3215 
  3216 * Pure/syntax: builtin parse translation for "_constify" turns valued
  3217 tokens into AST constants;
  3218 
  3219 * Pure/syntax: prefer later declarations of translations and print
  3220 translation functions; potential INCOMPATIBILITY: need to reverse
  3221 multiple declarations for same syntax element constant;
  3222 
  3223 * Pure/show_hyps reset by default (in accordance to existing Isar
  3224 practice);
  3225 
  3226 * Provers/classical: renamed addaltern to addafter, addSaltern to
  3227 addSafter;
  3228 
  3229 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  3230 as well;
  3231 
  3232 * system: tested support for MacOS X; should be able to get Isabelle +
  3233 Proof General to work in a plain Terminal after installing Poly/ML
  3234 (e.g. from the Isabelle distribution area) and GNU bash alone
  3235 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  3236 support requires further installations, e.g. from
  3237 http://fink.sourceforge.net/);
  3238 
  3239 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  3240 
  3241 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  3242 of 40 MB), cf. ML_OPTIONS;
  3243 
  3244 * system: Proof General keywords specification is now part of the
  3245 Isabelle distribution (see etc/isar-keywords.el);
  3246 
  3247 * system: support for persistent Proof General sessions (refrain from
  3248 outdating all loaded theories on startup); user may create writable
  3249 logic images like this: ``isabelle -q HOL Test'';
  3250 
  3251 * system: smart selection of Isabelle process versus Isabelle
  3252 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  3253 run both "isabelle" and "Isabelle" even if file names are badly
  3254 damaged (executable inspects the case of the first letter of its own
  3255 name); added separate "isabelle-process" and "isabelle-interface";
  3256 
  3257 * system: refrain from any attempt at filtering input streams; no
  3258 longer support ``8bit'' encoding of old isabelle font, instead proper
  3259 iso-latin characters may now be used; the related isatools
  3260 "symbolinput" and "nonascii" have disappeared as well;
  3261 
  3262 * system: removed old "xterm" interface (the print modes "xterm" and
  3263 "xterm_color" are still available for direct use in a suitable
  3264 terminal);
  3265 
  3266 
  3267 
  3268 New in Isabelle99-2 (February 2001)
  3269 -----------------------------------
  3270 
  3271 *** Overview of INCOMPATIBILITIES ***
  3272 
  3273 * HOL: please note that theories in the Library and elsewhere often use the
  3274 new-style (Isar) format; to refer to their theorems in an ML script you must
  3275 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  3276 
  3277 * HOL: inductive package no longer splits induction rule aggressively,
  3278 but only as far as specified by the introductions given; the old
  3279 format may be recovered via ML function complete_split_rule or attribute
  3280 'split_rule (complete)';
  3281 
  3282 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  3283 gfp_Tarski to gfp_unfold;
  3284 
  3285 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  3286 
  3287 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  3288 relation); infix "^^" has been renamed "``"; infix "``" has been
  3289 renamed "`"; "univalent" has been renamed "single_valued";
  3290 
  3291 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  3292 operation;
  3293 
  3294 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  3295 
  3296 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  3297 
  3298 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  3299 consequence, it is no longer monotonic wrt. the local goal context
  3300 (which is now passed through the inductive cases);
  3301 
  3302 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  3303 \<gg> to \<ggreater>;
  3304 
  3305 
  3306 *** Document preparation ***
  3307 
  3308 * \isabellestyle{NAME} selects version of Isabelle output (currently
  3309 available: are "it" for near math-mode best-style output, "sl" for
  3310 slanted text style, and "tt" for plain type-writer; if no
  3311 \isabellestyle command is given, output is according to slanted
  3312 type-writer);
  3313 
  3314 * support sub/super scripts (for single symbols only), input syntax is
  3315 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  3316 
  3317 * some more standard symbols; see Appendix A of the system manual for
  3318 the complete list of symbols defined in isabellesym.sty;
  3319 
  3320 * improved isabelle style files; more abstract symbol implementation
  3321 (should now use \isamath{...} and \isatext{...} in custom symbol
  3322 definitions);
  3323 
  3324 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  3325 state; Note that presentation of goal states does not conform to
  3326 actual human-readable proof documents.  Please do not include goal
  3327 states into document output unless you really know what you are doing!
  3328 
  3329 * proper indentation of antiquoted output with proportional LaTeX
  3330 fonts;
  3331 
  3332 * no_document ML operator temporarily disables LaTeX document
  3333 generation;
  3334 
  3335 * isatool unsymbolize tunes sources for plain ASCII communication;
  3336 
  3337 
  3338 *** Isar ***
  3339 
  3340 * Pure: Isar now suffers initial goal statements to contain unbound
  3341 schematic variables (this does not conform to actual readable proof
  3342 documents, due to unpredictable outcome and non-compositional proof
  3343 checking); users who know what they are doing may use schematic goals
  3344 for Prolog-style synthesis of proven results;
  3345 
  3346 * Pure: assumption method (an implicit finishing) now handles actual
  3347 rules as well;
  3348 
  3349 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  3350 initial goal, declare "that" only as Pure intro (only for single
  3351 steps); the "that" rule assumption may now be involved in implicit
  3352 finishing, thus ".." becomes a feasible for trivial obtains;
  3353 
  3354 * Pure: default proof step now includes 'intro_classes'; thus trivial
  3355 instance proofs may be performed by "..";
  3356 
  3357 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  3358 statements as well;
  3359 
  3360 * Pure: more robust selection of calculational rules;
  3361 
  3362 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  3363 rule (as well as the assumption rule);
  3364 
  3365 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  3366 lemmas, using the graph browser tool;
  3367 
  3368 * Pure: predict failure of "show" in interactive mode;
  3369 
  3370 * Pure: 'thms_containing' now takes actual terms as arguments;
  3371 
  3372 * HOL: improved method 'induct' --- now handles non-atomic goals
  3373 (potential INCOMPATIBILITY); tuned error handling;
  3374 
  3375 * HOL: cases and induct rules now provide explicit hints about the
  3376 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  3377 any remaining facts are inserted into the goal verbatim;
  3378 
  3379 * HOL: local contexts (aka cases) may now contain term bindings as
  3380 well; the 'cases' and 'induct' methods new provide a ?case binding for
  3381 the result to be shown in each case;
  3382 
  3383 * HOL: added 'recdef_tc' command;
  3384 
  3385 * isatool convert assists in eliminating legacy ML scripts;
  3386 
  3387 
  3388 *** HOL ***
  3389 
  3390 * HOL/Library: a collection of generic theories to be used together
  3391 with main HOL; the theory loader path already includes this directory
  3392 by default; the following existing theories have been moved here:
  3393 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  3394 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  3395 
  3396 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  3397 modelling and verification task performed in Isabelle/HOL +
  3398 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  3399 
  3400 * HOL/Algebra: special summation operator SUM no longer exists, it has
  3401 been replaced by setsum; infix 'assoc' now has priority 50 (like
  3402 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  3403 'domain', this makes the theory consistent with mathematical
  3404 literature;
  3405 
  3406 * HOL basics: added overloaded operations "inverse" and "divide"
  3407 (infix "/"), syntax for generic "abs" operation, generic summation
  3408 operator \<Sum>;
  3409 
  3410 * HOL/typedef: simplified package, provide more useful rules (see also
  3411 HOL/subset.thy);
  3412 
  3413 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  3414 now expressed as a proper nested rule (old-style tactic scripts may
  3415 require atomize_strip_tac to cope with non-atomic premises);
  3416 
  3417 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  3418 to "split_conv" (old name still available for compatibility);
  3419 
  3420 * HOL: improved concrete syntax for strings (e.g. allows translation
  3421 rules with string literals);
  3422 
  3423 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  3424  and Fleuriot's mechanization of analysis, including the transcendental
  3425  functions for the reals;
  3426 
  3427 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  3428 
  3429 
  3430 *** CTT ***
  3431 
  3432 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  3433 "lam" is displayed as TWO lambda-symbols
  3434 
  3435 * CTT: theory Main now available, containing everything (that is, Bool
  3436 and Arith);
  3437 
  3438 
  3439 *** General ***
  3440 
  3441 * Pure: the Simplifier has been implemented properly as a derived rule
  3442 outside of the actual kernel (at last!); the overall performance
  3443 penalty in practical applications is about 50%, while reliability of
  3444 the Isabelle inference kernel has been greatly improved;
  3445 
  3446 * print modes "brackets" and "no_brackets" control output of nested =>
  3447 (types) and ==> (props); the default behaviour is "brackets";
  3448 
  3449 * Provers: fast_tac (and friends) now handle actual object-logic rules
  3450 as assumptions as well;
  3451 
  3452 * system: support Poly/ML 4.0;
  3453 
  3454 * system: isatool install handles KDE version 1 or 2;
  3455 
  3456 
  3457 
  3458 New in Isabelle99-1 (October 2000)
  3459 ----------------------------------
  3460 
  3461 *** Overview of INCOMPATIBILITIES ***
  3462 
  3463 * HOL: simplification of natural numbers is much changed; to partly
  3464 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  3465 issue the following ML commands:
  3466 
  3467   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  3468   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  3469 
  3470 * HOL: simplification no longer dives into case-expressions; this is
  3471 controlled by "t.weak_case_cong" for each datatype t;
  3472 
  3473 * HOL: nat_less_induct renamed to less_induct;
  3474 
  3475 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  3476 fixsome to patch .thy and .ML sources automatically;
  3477 
  3478   select_equality  -> some_equality
  3479   select_eq_Ex     -> some_eq_ex
  3480   selectI2EX       -> someI2_ex
  3481   selectI2         -> someI2
  3482   selectI          -> someI
  3483   select1_equality -> some1_equality
  3484   Eps_sym_eq       -> some_sym_eq_trivial
  3485   Eps_eq           -> some_eq_trivial
  3486 
  3487 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  3488 
  3489 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  3490 instead);
  3491 
  3492 * HOL: the recursion equations generated by 'recdef' are now called
  3493 f.simps instead of f.rules;
  3494 
  3495 * HOL: qed_spec_mp now also handles bounded ALL as well;
  3496 
  3497 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  3498 sometimes be needed;
  3499 
  3500 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  3501 
  3502 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  3503 
  3504 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  3505 product is now "<*>" instead of "Times"; the lexicographic product is
  3506 now "<*lex*>" instead of "**";
  3507 
  3508 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  3509 of main HOL, but was unused); better use HOL's datatype package;
  3510 
  3511 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  3512 the old syntax may be recovered as follows:
  3513 
  3514   syntax (symbols)
  3515     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  3516       (infixl "\\<oplus>" 100)
  3517 
  3518 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3519 
  3520 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  3521 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  3522 internally;
  3523 
  3524 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  3525 changed from A/r to A//r;
  3526 
  3527 * ZF: new treatment of arithmetic (nat & int) may break some old
  3528 proofs;
  3529 
  3530 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  3531 rulify -> rule_format, elimify -> elim_format, ...);
  3532 
  3533 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3534 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  3535 should have to change intro!! to intro? only); replaced "delrule" by
  3536 "rule del";
  3537 
  3538 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  3539 
  3540 * Provers: strengthened force_tac by using new first_best_tac;
  3541 
  3542 * LaTeX document preparation: several changes of isabelle.sty (see
  3543 lib/texinputs);
  3544 
  3545 
  3546 *** Document preparation ***
  3547 
  3548 * formal comments (text blocks etc.) in new-style theories may now
  3549 contain antiquotations of thm/prop/term/typ/text to be presented
  3550 according to latex print mode; concrete syntax is like this:
  3551 @{term[show_types] "f(x) = a + x"};
  3552 
  3553 * isatool mkdir provides easy setup of Isabelle session directories,
  3554 including proper document sources;
  3555 
  3556 * generated LaTeX sources are now deleted after successful run
  3557 (isatool document -c); may retain a copy somewhere else via -D option
  3558 of isatool usedir;
  3559 
  3560 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  3561 style files, achieving self-contained LaTeX sources and simplifying
  3562 LaTeX debugging;
  3563 
  3564 * old-style theories now produce (crude) LaTeX output as well;
  3565 
  3566 * browser info session directories are now self-contained (may be put
  3567 on WWW server seperately); improved graphs of nested sessions; removed
  3568 graph for 'all sessions';
  3569 
  3570 * several improvements in isabelle style files; \isabellestyle{it}
  3571 produces fake math mode output; \isamarkupheader is now \section by
  3572 default; see lib/texinputs/isabelle.sty etc.;
  3573 
  3574 
  3575 *** Isar ***
  3576 
  3577 * Isar/Pure: local results and corresponding term bindings are now
  3578 subject to Hindley-Milner polymorphism (similar to ML); this
  3579 accommodates incremental type-inference very nicely;
  3580 
  3581 * Isar/Pure: new derived language element 'obtain' supports
  3582 generalized existence reasoning;
  3583 
  3584 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  3585 support accumulation of results, without applying any rules yet;
  3586 useful to collect intermediate results without explicit name
  3587 references, and for use with transitivity rules with more than 2
  3588 premises;
  3589 
  3590 * Isar/Pure: scalable support for case-analysis type proofs: new
  3591 'case' language element refers to local contexts symbolically, as
  3592 produced by certain proof methods; internally, case names are attached
  3593 to theorems as "tags";
  3594 
  3595 * Isar/Pure: theory command 'hide' removes declarations from
  3596 class/type/const name spaces;
  3597 
  3598 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  3599 indicate potential overloading;
  3600 
  3601 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  3602 
  3603 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  3604 "{a,b,c}" instead of {a,b,c};
  3605 
  3606 * Isar/Pure now provides its own version of intro/elim/dest
  3607 attributes; useful for building new logics, but beware of confusion
  3608 with the version in Provers/classical;
  3609 
  3610 * Isar/Pure: the local context of (non-atomic) goals is provided via
  3611 case name 'antecedent';
  3612 
  3613 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  3614 to the current context is now done automatically);
  3615 
  3616 * Isar/Pure: theory command 'method_setup' provides a simple interface
  3617 for definining proof methods in ML;
  3618 
  3619 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3620 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  3621 most cases, one should have to change intro!! to intro? only);
  3622 replaced "delrule" by "rule del";
  3623 
  3624 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  3625 'symmetric' attribute (the latter supercedes [RS sym]);
  3626 
  3627 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  3628 method modifier); 'simp' method: 'only:' modifier removes loopers as
  3629 well (including splits);
  3630 
  3631 * Isar/Provers: Simplifier and Classical methods now support all kind
  3632 of modifiers used in the past, including 'cong', 'iff', etc.
  3633 
  3634 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  3635 of Simplifier and Classical reasoner);
  3636 
  3637 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  3638 now support named cases; major packages (inductive, datatype, primrec,
  3639 recdef) support case names and properly name parameters;
  3640 
  3641 * Isar/HOL: new transitivity rules for substitution in inequalities --
  3642 monotonicity conditions are extracted to be proven at end of
  3643 calculations;
  3644 
  3645 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  3646 method anyway;
  3647 
  3648 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  3649 split_if split_if_asm; datatype package provides theorems foo.splits =
  3650 foo.split foo.split_asm for each datatype;
  3651 
  3652 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  3653 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  3654 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  3655 use "(cases (simplified))" method in proper proof texts);
  3656 
  3657 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  3658 
  3659 * Isar: names of theorems etc. may be natural numbers as well;
  3660 
  3661 * Isar: 'pr' command: optional arguments for goals_limit and
  3662 ProofContext.prems_limit; no longer prints theory contexts, but only
  3663 proof states;
  3664 
  3665 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  3666 additional print modes to be specified; e.g. "pr(latex)" will print
  3667 proof state according to the Isabelle LaTeX style;
  3668 
  3669 * Isar: improved support for emulating tactic scripts, including proof
  3670 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  3671 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  3672 (for HOL datatypes);
  3673 
  3674 * Isar: simplified (more robust) goal selection of proof methods: 1st
  3675 goal, all goals, or explicit goal specifier (tactic emulation); thus
  3676 'proof method scripts' have to be in depth-first order;
  3677 
  3678 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  3679 
  3680 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  3681 should instead use individual commands for printing items
  3682 (print_commands, print_methods etc.);
  3683 
  3684 * Isar: added 'nothing' --- the empty list of theorems;
  3685 
  3686 
  3687 *** HOL ***
  3688 
  3689 * HOL/MicroJava: formalization of a fragment of Java, together with a
  3690 corresponding virtual machine and a specification of its bytecode
  3691 verifier and a lightweight bytecode verifier, including proofs of
  3692 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  3693 Cornelia Pusch (see also the homepage of project Bali at
  3694 http://isabelle.in.tum.de/Bali/);
  3695 
  3696 * HOL/Algebra: new theory of rings and univariate polynomials, by
  3697 Clemens Ballarin;
  3698 
  3699 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  3700 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  3701 Rasmussen;
  3702 
  3703 * HOL/Lattice: fundamental concepts of lattice theory and order
  3704 structures, including duals, properties of bounds versus algebraic
  3705 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  3706 Theorem for complete lattices etc.; may also serve as a demonstration
  3707 for abstract algebraic reasoning using axiomatic type classes, and
  3708 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  3709 
  3710 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  3711 von Oheimb;
  3712 
  3713 * HOL/IMPP: extension of IMP with local variables and mutually
  3714 recursive procedures, by David von Oheimb;
  3715 
  3716 * HOL/Lambda: converted into new-style theory and document;
  3717 
  3718 * HOL/ex/Multiquote: example of multiple nested quotations and
  3719 anti-quotations -- basically a generalized version of de-Bruijn
  3720 representation; very useful in avoiding lifting of operations;
  3721 
  3722 * HOL/record: added general record equality rule to simpset; fixed
  3723 select-update simplification procedure to handle extended records as
  3724 well; admit "r" as field name;
  3725 
  3726 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  3727 other numeric types and also as the identity of groups, rings, etc.;
  3728 
  3729 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  3730 Types nat and int belong to this axclass;
  3731 
  3732 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  3733    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  3734    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  3735   two terms #m*u and #n*u are replaced by #(m+n)*u
  3736     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  3737   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  3738     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  3739 
  3740 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  3741 powerful prover for predicate logic but knows nothing of clasets; see
  3742 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  3743 
  3744 * HOL: new version of "case_tac" subsumes both boolean case split and
  3745 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  3746 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  3747 
  3748 * HOL: simplification no longer dives into case-expressions: only the
  3749 selector expression is simplified, but not the remaining arms; to
  3750 enable full simplification of case-expressions for datatype t, you may
  3751 remove t.weak_case_cong from the simpset, either globally (Delcongs
  3752 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  3753 
  3754 * HOL/recdef: the recursion equations generated by 'recdef' for
  3755 function 'f' are now called f.simps instead of f.rules; if all
  3756 termination conditions are proved automatically, these simplification
  3757 rules are added to the simpset, as in primrec; rules may be named
  3758 individually as well, resulting in a separate list of theorems for
  3759 each equation;
  3760 
  3761 * HOL/While is a new theory that provides a while-combinator. It
  3762 permits the definition of tail-recursive functions without the
  3763 provision of a termination measure. The latter is necessary once the
  3764 invariant proof rule for while is applied.
  3765 
  3766 * HOL: new (overloaded) notation for the set of elements below/above
  3767 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  3768 
  3769 * HOL: theorems impI, allI, ballI bound as "strip";
  3770 
  3771 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  3772 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  3773 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  3774 
  3775 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3776 
  3777 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  3778 main HOL, but was unused);
  3779 
  3780 * HOL: fewer consts declared as global (e.g. have to refer to
  3781 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  3782 
  3783 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  3784 in case of overlap with user translations (e.g. judgements over
  3785 tuples); (note that the underlying logical represenation is still
  3786 bogus);
  3787 
  3788 
  3789 *** ZF ***
  3790 
  3791 * ZF: simplification automatically cancels common terms in arithmetic
  3792 expressions over nat and int;
  3793 
  3794 * ZF: new treatment of nat to minimize type-checking: all operators
  3795 coerce their operands to a natural number using the function natify,
  3796 making the algebraic laws unconditional;
  3797 
  3798 * ZF: as above, for int: operators coerce their operands to an integer
  3799 using the function intify;
  3800 
  3801 * ZF: the integer library now contains many of the usual laws for the
  3802 orderings, including $<=, and monotonicity laws for $+ and $*;
  3803 
  3804 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  3805 simplification;
  3806 
  3807 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  3808 to the simplifier and classical reasoner simultaneously;
  3809 
  3810 
  3811 *** General ***
  3812 
  3813 * Provers: blast_tac now handles actual object-logic rules as
  3814 assumptions; note that auto_tac uses blast_tac internally as well;
  3815 
  3816 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  3817 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  3818 
  3819 * Provers: delrules now handles destruct rules as well (no longer need
  3820 explicit make_elim);
  3821 
  3822 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  3823   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3824 use instead the strong form,
  3825   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3826 in HOL, FOL and ZF the function cla_make_elim will create such rules
  3827 from destruct-rules;
  3828 
  3829 * Provers: Simplifier.easy_setup provides a fast path to basic
  3830 Simplifier setup for new object-logics;
  3831 
  3832 * Pure: AST translation rules no longer require constant head on LHS;
  3833 
  3834 * Pure: improved name spaces: ambiguous output is qualified; support
  3835 for hiding of names;
  3836 
  3837 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  3838 XSYMBOL_HOME; no longer need to do manual configuration in most
  3839 situations;
  3840 
  3841 * system: compression of ML heaps images may now be controlled via -c
  3842 option of isabelle and isatool usedir (currently only observed by
  3843 Poly/ML);
  3844 
  3845 * system: isatool installfonts may handle X-Symbol fonts as well (very
  3846 useful for remote X11);
  3847 
  3848 * system: provide TAGS file for Isabelle sources;
  3849 
  3850 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  3851 order;
  3852 
  3853 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  3854 timing flag supersedes proof_timing and Toplevel.trace;
  3855 
  3856 * ML: new combinators |>> and |>>> for incremental transformations
  3857 with secondary results (e.g. certain theory extensions):
  3858 
  3859 * ML: PureThy.add_defs gets additional argument to indicate potential
  3860 overloading (usually false);
  3861 
  3862 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  3863 results;
  3864 
  3865 
  3866 
  3867 New in Isabelle99 (October 1999)
  3868 --------------------------------
  3869 
  3870 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3871 
  3872 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  3873 are no longer simplified.  (This allows the simplifier to unfold recursive
  3874 functional programs.)  To restore the old behaviour, declare
  3875 
  3876     Delcongs [if_weak_cong];
  3877 
  3878 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  3879 complement;
  3880 
  3881 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  3882 
  3883 * HOL/datatype: mutual_induct_tac no longer exists --
  3884   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  3885 
  3886 * HOL/typedef: fixed type inference for representing set; type
  3887 arguments now have to occur explicitly on the rhs as type constraints;
  3888 
  3889 * ZF: The con_defs part of an inductive definition may no longer refer
  3890 to constants declared in the same theory;
  3891 
  3892 * HOL, ZF: the function mk_cases, generated by the inductive
  3893 definition package, has lost an argument.  To simplify its result, it
  3894 uses the default simpset instead of a supplied list of theorems.
  3895 
  3896 * HOL/List: the constructors of type list are now Nil and Cons;
  3897 
  3898 * Simplifier: the type of the infix ML functions
  3899         setSSolver addSSolver setSolver addSolver
  3900 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  3901 for packaging solvers. A solver is created via
  3902         mk_solver: string -> (thm list -> int -> tactic) -> solver
  3903 where the string argument is only a comment.
  3904 
  3905 
  3906 *** Proof tools ***
  3907 
  3908 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  3909 decision procedure for linear arithmetic. Currently it is used for
  3910 types `nat', `int', and `real' in HOL (see below); it can, should and
  3911 will be instantiated for other types and logics as well.
  3912 
  3913 * The simplifier now accepts rewrite rules with flexible heads, eg
  3914      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  3915   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  3916   matching.
  3917 
  3918 
  3919 *** General ***
  3920 
  3921 * New Isabelle/Isar subsystem provides an alternative to traditional
  3922 tactical theorem proving; together with the ProofGeneral/isar user
  3923 interface it offers an interactive environment for developing human
  3924 readable proof documents (Isar == Intelligible semi-automated
  3925 reasoning); for further information see isatool doc isar-ref,
  3926 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  3927 
  3928 * improved and simplified presentation of theories: better HTML markup
  3929 (including colors), graph views in several sizes; isatool usedir now
  3930 provides a proper interface for user theories (via -P option); actual
  3931 document preparation based on (PDF)LaTeX is available as well (for
  3932 new-style theories only); see isatool doc system for more information;
  3933 
  3934 * native support for Proof General, both for classic Isabelle and
  3935 Isabelle/Isar;
  3936 
  3937 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  3938 using the graph browser tool;
  3939 
  3940 * Isabelle manuals now also available as PDF;
  3941 
  3942 * theory loader rewritten from scratch (may not be fully
  3943 bug-compatible); old loadpath variable has been replaced by show_path,
  3944 add_path, del_path, reset_path functions; new operations such as
  3945 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  3946 isatool doc ref);
  3947 
  3948 * improved isatool install: option -k creates KDE application icon,
  3949 option -p DIR installs standalone binaries;
  3950 
  3951 * added ML_PLATFORM setting (useful for cross-platform installations);
  3952 more robust handling of platform specific ML images for SML/NJ;
  3953 
  3954 * the settings environment is now statically scoped, i.e. it is never
  3955 created again in sub-processes invoked from isabelle, isatool, or
  3956 Isabelle;
  3957 
  3958 * path element specification '~~' refers to '$ISABELLE_HOME';
  3959 
  3960 * in locales, the "assumes" and "defines" parts may be omitted if
  3961 empty;
  3962 
  3963 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  3964 long arrows);
  3965 
  3966 * new print_mode "HTML";
  3967 
  3968 * new flag show_tags controls display of tags of theorems (which are
  3969 basically just comments that may be attached by some tools);
  3970 
  3971 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  3972 mode and goal output format:
  3973 
  3974 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  3975 244c244
  3976 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  3977 ---
  3978 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  3979 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  3980 181c181
  3981 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  3982 ---
  3983 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  3984 
  3985 * function bind_thms stores lists of theorems (cf. bind_thm);
  3986 
  3987 * new shorthand tactics ftac, eatac, datac, fatac;
  3988 
  3989 * qed (and friends) now accept "" as result name; in that case the
  3990 theorem is not stored, but proper checks and presentation of the
  3991 result still apply;
  3992 
  3993 * theorem database now also indexes constants "Trueprop", "all",
  3994 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  3995 
  3996 
  3997 *** HOL ***
  3998 
  3999 ** HOL arithmetic **
  4000 
  4001 * There are now decision procedures for linear arithmetic over nat and
  4002 int:
  4003 
  4004 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  4005 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  4006 are treated as atomic; subformulae not involving type `nat' or `int'
  4007 are ignored; quantified subformulae are ignored unless they are
  4008 positive universal or negative existential. The tactic has to be
  4009 invoked by hand and can be a little bit slow. In particular, the
  4010 running time is exponential in the number of occurrences of `min' and
  4011 `max', and `-' on `nat'.
  4012 
  4013 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  4014 (negated) (in)equalities among the premises and the conclusion into
  4015 account (i.e. no compound formulae) and does not know about `min' and
  4016 `max', and `-' on `nat'. It is fast and is used automatically by the
  4017 simplifier.
  4018 
  4019 NB: At the moment, these decision procedures do not cope with mixed
  4020 nat/int formulae where the two parts interact, such as `m < n ==>
  4021 int(m) < int(n)'.
  4022 
  4023 * HOL/Numeral provides a generic theory of numerals (encoded
  4024 efficiently as bit strings); setup for types nat/int/real is in place;
  4025 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  4026 int, existing theories and proof scripts may require a few additional
  4027 type constraints;
  4028 
  4029 * integer division and remainder can now be performed on constant
  4030 arguments;
  4031 
  4032 * many properties of integer multiplication, division and remainder
  4033 are now available;
  4034 
  4035 * An interface to the Stanford Validity Checker (SVC) is available through the
  4036 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  4037 are proved automatically.  SVC must be installed separately, and its results
  4038 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  4039 invocation of the underlying oracle).  For SVC see
  4040   http://verify.stanford.edu/SVC
  4041 
  4042 * IsaMakefile: the HOL-Real target now builds an actual image;
  4043 
  4044 
  4045 ** HOL misc **
  4046 
  4047 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  4048 (in Isabelle/Isar) -- by Gertrud Bauer;
  4049 
  4050 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  4051 analysis for assembly languages with subtypes;
  4052 
  4053 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  4054 -- avoids syntactic ambiguities and treats state, transition, and
  4055 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  4056 changed syntax and (many) tactics;
  4057 
  4058 * HOL/inductive: Now also handles more general introduction rules such
  4059   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  4060   theorems are now maintained within the theory (maintained via the
  4061   "mono" attribute);
  4062 
  4063 * HOL/datatype: Now also handles arbitrarily branching datatypes
  4064   (using function types) such as
  4065 
  4066   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  4067 
  4068 * HOL/record: record_simproc (part of the default simpset) takes care
  4069 of selectors applied to updated records; record_split_tac is no longer
  4070 part of the default claset; update_defs may now be removed from the
  4071 simpset in many cases; COMPATIBILITY: old behavior achieved by
  4072 
  4073   claset_ref () := claset() addSWrapper record_split_wrapper;
  4074   Delsimprocs [record_simproc]
  4075 
  4076 * HOL/typedef: fixed type inference for representing set; type
  4077 arguments now have to occur explicitly on the rhs as type constraints;
  4078 
  4079 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  4080 names rather than an ML expression;
  4081 
  4082 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  4083 supplied later.  Program schemes can be defined, such as
  4084     "While B C s = (if B s then While B C (C s) else s)"
  4085 where the well-founded relation can be chosen after B and C have been given.
  4086 
  4087 * HOL/List: the constructors of type list are now Nil and Cons;
  4088 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  4089 course, ML tools referring to List.list.op # etc. have to be adapted;
  4090 
  4091 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  4092 disabled by default; run isabelle with option -m HOL to get back to
  4093 the original Gordon/HOL-style output;
  4094 
  4095 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  4096 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  4097 
  4098 * HOL basic syntax simplified (more orthogonal): all variants of
  4099 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  4100 Eps operator is provided as well: "SOME x. P[x]";
  4101 
  4102 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  4103 
  4104 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  4105 thus available for user theories;
  4106 
  4107 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  4108 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  4109 time;
  4110 
  4111 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  4112 several times and then mp;
  4113 
  4114 
  4115 *** LK ***
  4116 
  4117 * the notation <<...>> is now available as a notation for sequences of
  4118 formulas;
  4119 
  4120 * the simplifier is now installed
  4121 
  4122 * the axiom system has been generalized (thanks to Soren Heilmann)
  4123 
  4124 * the classical reasoner now has a default rule database
  4125 
  4126 
  4127 *** ZF ***
  4128 
  4129 * new primrec section allows primitive recursive functions to be given
  4130 directly (as in HOL) over datatypes and the natural numbers;
  4131 
  4132 * new tactics induct_tac and exhaust_tac for induction (or case
  4133 analysis) over datatypes and the natural numbers;
  4134 
  4135 * the datatype declaration of type T now defines the recursor T_rec;
  4136 
  4137 * simplification automatically does freeness reasoning for datatype
  4138 constructors;
  4139 
  4140 * automatic type-inference, with AddTCs command to insert new
  4141 type-checking rules;
  4142 
  4143 * datatype introduction rules are now added as Safe Introduction rules
  4144 to the claset;
  4145 
  4146 * the syntax "if P then x else y" is now available in addition to
  4147 if(P,x,y);
  4148 
  4149 
  4150 *** Internal programming interfaces ***
  4151 
  4152 * tuned simplifier trace output; new flag debug_simp;
  4153 
  4154 * structures Vartab / Termtab (instances of TableFun) offer efficient
  4155 tables indexed by indexname_ord / term_ord (compatible with aconv);
  4156 
  4157 * AxClass.axclass_tac lost the theory argument;
  4158 
  4159 * tuned current_goals_markers semantics: begin / end goal avoids
  4160 printing empty lines;
  4161 
  4162 * removed prs and prs_fn hook, which was broken because it did not
  4163 include \n in its semantics, forcing writeln to add one
  4164 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  4165 string -> unit if you really want to output text without newline;
  4166 
  4167 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  4168 plain output, interface builders may have to enable 'isabelle_font'
  4169 mode to get Isabelle font glyphs as before;
  4170 
  4171 * refined token_translation interface; INCOMPATIBILITY: output length
  4172 now of type real instead of int;
  4173 
  4174 * theory loader actions may be traced via new ThyInfo.add_hook
  4175 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  4176 your own database of information attached to *whole* theories -- as
  4177 opposed to intra-theory data slots offered via TheoryDataFun;
  4178 
  4179 * proper handling of dangling sort hypotheses (at last!);
  4180 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  4181 extra sort hypotheses that can be witnessed from the type signature;
  4182 the force_strip_shyps flag is gone, any remaining shyps are simply
  4183 left in the theorem (with a warning issued by strip_shyps_warning);
  4184 
  4185 
  4186 
  4187 New in Isabelle98-1 (October 1998)
  4188 ----------------------------------
  4189 
  4190 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4191 
  4192 * several changes of automated proof tools;
  4193 
  4194 * HOL: major changes to the inductive and datatype packages, including
  4195 some minor incompatibilities of theory syntax;
  4196 
  4197 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  4198 called `inj_on';
  4199 
  4200 * HOL: removed duplicate thms in Arith:
  4201   less_imp_add_less  should be replaced by  trans_less_add1
  4202   le_imp_add_le      should be replaced by  trans_le_add1
  4203 
  4204 * HOL: unary minus is now overloaded (new type constraints may be
  4205 required);
  4206 
  4207 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  4208 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  4209 now taken as an integer constant.
  4210 
  4211 * Pure: ML function 'theory_of' renamed to 'theory';
  4212 
  4213 
  4214 *** Proof tools ***
  4215 
  4216 * Simplifier:
  4217   1. Asm_full_simp_tac is now more aggressive.
  4218      1. It will sometimes reorient premises if that increases their power to
  4219         simplify.
  4220      2. It does no longer proceed strictly from left to right but may also
  4221         rotate premises to achieve further simplification.
  4222      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  4223      old Asm_full_simp_tac in that it does not rotate premises.
  4224   2. The simplifier now knows a little bit about nat-arithmetic.
  4225 
  4226 * Classical reasoner: wrapper mechanism for the classical reasoner now
  4227 allows for selected deletion of wrappers, by introduction of names for
  4228 wrapper functionals.  This implies that addbefore, addSbefore,
  4229 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  4230 and that adding two tactics with the same name overwrites the first
  4231 one (emitting a warning).
  4232   type wrapper = (int -> tactic) -> (int -> tactic)
  4233   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  4234   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  4235   delWrapper, delSWrapper: claset *  string            -> claset
  4236   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  4237 
  4238 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  4239 semantics; addbefore now affects only the unsafe part of step_tac
  4240 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  4241 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  4242 by Force_tac;
  4243 
  4244 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  4245 compWrapper; added safe wrapper (and access functions for it);
  4246 
  4247 * HOL/split_all_tac is now much faster and fails if there is nothing
  4248 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  4249 and the names of the automatically generated variables have changed.
  4250 split_all_tac has moved within claset() from unsafe wrappers to safe
  4251 wrappers, which means that !!-bound variables are split much more
  4252 aggressively, and safe_tac and clarify_tac now split such variables.
  4253 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  4254 Note: the same holds for record_split_tac, which does the job of
  4255 split_all_tac for record fields.
  4256 
  4257 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  4258 permanently to the default simpset using Addsplits just like
  4259 Addsimps. They can be removed via Delsplits just like
  4260 Delsimps. Lower-case versions are also available.
  4261 
  4262 * HOL/Simplifier: The rule split_if is now part of the default
  4263 simpset. This means that the simplifier will eliminate all occurrences
  4264 of if-then-else in the conclusion of a goal. To prevent this, you can
  4265 either remove split_if completely from the default simpset by
  4266 `Delsplits [split_if]' or remove it in a specific call of the
  4267 simplifier using `... delsplits [split_if]'.  You can also add/delete
  4268 other case splitting rules to/from the default simpset: every datatype
  4269 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  4270 t is the name of the datatype).
  4271 
  4272 * Classical reasoner / Simplifier combination: new force_tac (and
  4273 derivatives Force_tac, force) combines rewriting and classical
  4274 reasoning (and whatever other tools) similarly to auto_tac, but is
  4275 aimed to solve the given subgoal completely.
  4276 
  4277 
  4278 *** General ***
  4279 
  4280 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  4281 and `goalw': the theory is no longer needed as an explicit argument -
  4282 the current theory context is used; assumptions are no longer returned
  4283 at the ML-level unless one of them starts with ==> or !!; it is
  4284 recommended to convert to these new commands using isatool fixgoal
  4285 (backup your sources first!);
  4286 
  4287 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  4288 the current theory context, and 'theory' to lookup stored theories;
  4289 
  4290 * new theory section 'locale' for declaring constants, assumptions and
  4291 definitions that have local scope;
  4292 
  4293 * new theory section 'nonterminals' for purely syntactic types;
  4294 
  4295 * new theory section 'setup' for generic ML setup functions
  4296 (e.g. package initialization);
  4297 
  4298 * the distribution now includes Isabelle icons: see
  4299 lib/logo/isabelle-{small,tiny}.xpm;
  4300 
  4301 * isatool install - install binaries with absolute references to
  4302 ISABELLE_HOME/bin;
  4303 
  4304 * isatool logo -- create instances of the Isabelle logo (as EPS);
  4305 
  4306 * print mode 'emacs' reserved for Isamode;
  4307 
  4308 * support multiple print (ast) translations per constant name;
  4309 
  4310 * theorems involving oracles are now printed with a suffixed [!];
  4311 
  4312 
  4313 *** HOL ***
  4314 
  4315 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  4316 
  4317 * HOL/inductive package reorganized and improved: now supports mutual
  4318 definitions such as
  4319 
  4320   inductive EVEN ODD
  4321     intrs
  4322       null "0 : EVEN"
  4323       oddI "n : EVEN ==> Suc n : ODD"
  4324       evenI "n : ODD ==> Suc n : EVEN"
  4325 
  4326 new theorem list "elims" contains an elimination rule for each of the
  4327 recursive sets; inductive definitions now handle disjunctive premises
  4328 correctly (also ZF);
  4329 
  4330 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  4331 "mutual_induct" no longer exists - the induction rule is always
  4332 contained in "induct";
  4333 
  4334 
  4335 * HOL/datatype package re-implemented and greatly improved: now
  4336 supports mutually recursive datatypes such as
  4337 
  4338   datatype
  4339     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  4340             | SUM ('a aexp) ('a aexp)
  4341             | DIFF ('a aexp) ('a aexp)
  4342             | NUM 'a
  4343   and
  4344     'a bexp = LESS ('a aexp) ('a aexp)
  4345             | AND ('a bexp) ('a bexp)
  4346             | OR ('a bexp) ('a bexp)
  4347 
  4348 as well as indirectly recursive datatypes such as
  4349 
  4350   datatype
  4351     ('a, 'b) term = Var 'a
  4352                   | App 'b ((('a, 'b) term) list)
  4353 
  4354 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  4355 induction on mutually / indirectly recursive datatypes.
  4356 
  4357 Primrec equations are now stored in theory and can be accessed via
  4358 <function_name>.simps.
  4359 
  4360 INCOMPATIBILITIES:
  4361 
  4362   - Theories using datatypes must now have theory Datatype as an
  4363     ancestor.
  4364   - The specific <typename>.induct_tac no longer exists - use the
  4365     generic induct_tac instead.
  4366   - natE has been renamed to nat.exhaust - use exhaust_tac
  4367     instead of res_inst_tac ... natE. Note that the variable
  4368     names in nat.exhaust differ from the names in natE, this
  4369     may cause some "fragile" proofs to fail.
  4370   - The theorems split_<typename>_case and split_<typename>_case_asm
  4371     have been renamed to <typename>.split and <typename>.split_asm.
  4372   - Since default sorts of type variables are now handled correctly,
  4373     some datatype definitions may have to be annotated with explicit
  4374     sort constraints.
  4375   - Primrec definitions no longer require function name and type
  4376     of recursive argument.
  4377 
  4378 Consider using isatool fixdatatype to adapt your theories and proof
  4379 scripts to the new package (backup your sources first!).
  4380 
  4381 
  4382 * HOL/record package: considerably improved implementation; now
  4383 includes concrete syntax for record types, terms, updates; theorems
  4384 for surjective pairing and splitting !!-bound record variables; proof
  4385 support is as follows:
  4386 
  4387   1) standard conversions (selectors or updates applied to record
  4388 constructor terms) are part of the standard simpset;
  4389 
  4390   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  4391 made part of standard simpset and claset via addIffs;
  4392 
  4393   3) a tactic for record field splitting (record_split_tac) is part of
  4394 the standard claset (addSWrapper);
  4395 
  4396 To get a better idea about these rules you may retrieve them via
  4397 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  4398 the name of your record type.
  4399 
  4400 The split tactic 3) conceptually simplifies by the following rule:
  4401 
  4402   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  4403 
  4404 Thus any record variable that is bound by meta-all will automatically
  4405 blow up into some record constructor term, consequently the
  4406 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  4407 solve record problems automatically.
  4408 
  4409 
  4410 * reorganized the main HOL image: HOL/Integ and String loaded by
  4411 default; theory Main includes everything;
  4412 
  4413 * automatic simplification of integer sums and comparisons, using cancellation;
  4414 
  4415 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  4416 
  4417 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  4418 
  4419 * many new identities for unions, intersections, set difference, etc.;
  4420 
  4421 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  4422 called split_if, split_split, split_sum_case and split_nat_case (to go
  4423 with add/delsplits);
  4424 
  4425 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  4426 (?x::unit) = (); this is made part of the default simpset, which COULD
  4427 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  4428 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  4429 unit_abs_eta_conv is added in order to counter the effect of
  4430 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  4431 %u.f();
  4432 
  4433 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  4434 makes more sense);
  4435 
  4436 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4437   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4438   disjointness reasoning but breaking a few old proofs.
  4439 
  4440 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  4441 to 'converse' from 'inverse' (for compatibility with ZF and some
  4442 literature);
  4443 
  4444 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  4445 the well-founded relation;
  4446 
  4447 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  4448     Compl A.  The "Compl" syntax remains available as input syntax for this
  4449     release ONLY.
  4450 
  4451 * HOL/Update: new theory of function updates:
  4452     f(a:=b) == %x. if x=a then b else f x
  4453 may also be iterated as in f(a:=b,c:=d,...);
  4454 
  4455 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  4456 
  4457 * HOL/List:
  4458   - new function list_update written xs[i:=v] that updates the i-th
  4459     list position. May also be iterated as in xs[i:=a,j:=b,...].
  4460   - new function `upt' written [i..j(] which generates the list
  4461     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  4462     bound write [i..j], which is a shorthand for [i..j+1(].
  4463   - new lexicographic orderings and corresponding wellfoundedness theorems.
  4464 
  4465 * HOL/Arith:
  4466   - removed 'pred' (predecessor) function;
  4467   - generalized some theorems about n-1;
  4468   - many new laws about "div" and "mod";
  4469   - new laws about greatest common divisors (see theory ex/Primes);
  4470 
  4471 * HOL/Relation: renamed the relational operator r^-1 "converse"
  4472 instead of "inverse";
  4473 
  4474 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  4475   of the multiset ordering;
  4476 
  4477 * directory HOL/Real: a construction of the reals using Dedekind cuts
  4478   (not included by default);
  4479 
  4480 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  4481 
  4482 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  4483   programs, i.e. different program variables may have different types.
  4484 
  4485 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4486   [previously, this check worked only if the rewrite rule was unconditional]
  4487   Now rew can involve either definitions or equalities (either == or =).
  4488 
  4489 
  4490 *** ZF ***
  4491 
  4492 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  4493   only the theorems proved on ZF.ML;
  4494 
  4495 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4496   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4497   disjointness reasoning but breaking a few old proofs.
  4498 
  4499 * ZF/Update: new theory of function updates
  4500     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  4501   may also be iterated as in f(a:=b,c:=d,...);
  4502 
  4503 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  4504 
  4505 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4506   [previously, this check worked only if the rewrite rule was unconditional]
  4507   Now rew can involve either definitions or equalities (either == or =).
  4508 
  4509 * case_tac provided for compatibility with HOL
  4510     (like the old excluded_middle_tac, but with subgoals swapped)
  4511 
  4512 
  4513 *** Internal programming interfaces ***
  4514 
  4515 * Pure: several new basic modules made available for general use, see
  4516 also src/Pure/README;
  4517 
  4518 * improved the theory data mechanism to support encapsulation (data
  4519 kind name replaced by private Object.kind, acting as authorization
  4520 key); new type-safe user interface via functor TheoryDataFun; generic
  4521 print_data function becomes basically useless;
  4522 
  4523 * removed global_names compatibility flag -- all theory declarations
  4524 are qualified by default;
  4525 
  4526 * module Pure/Syntax now offers quote / antiquote translation
  4527 functions (useful for Hoare logic etc. with implicit dependencies);
  4528 see HOL/ex/Antiquote for an example use;
  4529 
  4530 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  4531 cterm -> thm;
  4532 
  4533 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  4534 subgoal;
  4535 
  4536 * Display.print_goals function moved to Locale.print_goals;
  4537 
  4538 * standard print function for goals supports current_goals_markers
  4539 variable for marking begin of proof, end of proof, start of goal; the
  4540 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  4541 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  4542 for example;
  4543 
  4544 
  4545 
  4546 New in Isabelle98 (January 1998)
  4547 --------------------------------
  4548 
  4549 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4550 
  4551 * changed lexical syntax of terms / types: dots made part of long
  4552 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  4553 
  4554 * simpset (and claset) reference variable replaced by functions
  4555 simpset / simpset_ref;
  4556 
  4557 * no longer supports theory aliases (via merge) and non-trivial
  4558 implicit merge of thms' signatures;
  4559 
  4560 * most internal names of constants changed due to qualified names;
  4561 
  4562 * changed Pure/Sequence interface (see Pure/seq.ML);
  4563 
  4564 
  4565 *** General Changes ***
  4566 
  4567 * hierachically structured name spaces (for consts, types, axms, thms
  4568 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  4569 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  4570 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  4571 long_names for fully qualified output names; NOTE: ML programs
  4572 (special tactics, packages etc.) referring to internal names may have
  4573 to be adapted to cope with fully qualified names; in case of severe
  4574 backward campatibility problems try setting 'global_names' at compile
  4575 time to have enrything declared within a flat name space; one may also
  4576 fine tune name declarations in theories via the 'global' and 'local'
  4577 section;
  4578 
  4579 * reimplemented the implicit simpset and claset using the new anytype
  4580 data filed in signatures; references simpset:simpset ref etc. are
  4581 replaced by functions simpset:unit->simpset and
  4582 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  4583 to patch your ML files accordingly;
  4584 
  4585 * HTML output now includes theory graph data for display with Java
  4586 applet or isatool browser; data generated automatically via isatool
  4587 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  4588 
  4589 * defs may now be conditional; improved rewrite_goals_tac to handle
  4590 conditional equations;
  4591 
  4592 * defs now admits additional type arguments, using TYPE('a) syntax;
  4593 
  4594 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  4595 creates a new theory node; implicit merge of thms' signatures is
  4596 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  4597 transfer:theory->thm->thm in (rare) cases;
  4598 
  4599 * improved handling of draft signatures / theories; draft thms (and
  4600 ctyps, cterms) are automatically promoted to real ones;
  4601 
  4602 * slightly changed interfaces for oracles: admit many per theory, named
  4603 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  4604 
  4605 * print_goals: optional output of const types (set show_consts and
  4606 show_types);
  4607 
  4608 * improved output of warnings (###) and errors (***);
  4609 
  4610 * subgoal_tac displays a warning if the new subgoal has type variables;
  4611 
  4612 * removed old README and Makefiles;
  4613 
  4614 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  4615 
  4616 * removed obsolete init_pps and init_database;
  4617 
  4618 * deleted the obsolete tactical STATE, which was declared by
  4619     fun STATE tacfun st = tacfun st st;
  4620 
  4621 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  4622 (which abbreviates $HOME);
  4623 
  4624 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  4625 use isatool fixseq to adapt your ML programs (this works for fully
  4626 qualified references to the Sequence structure only!);
  4627 
  4628 * use_thy no longer requires writable current directory; it always
  4629 reloads .ML *and* .thy file, if either one is out of date;
  4630 
  4631 
  4632 *** Classical Reasoner ***
  4633 
  4634 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  4635 tactics that use classical reasoning to simplify a subgoal without
  4636 splitting it into several subgoals;
  4637 
  4638 * Safe_tac: like safe_tac but uses the default claset;
  4639 
  4640 
  4641 *** Simplifier ***
  4642 
  4643 * added simplification meta rules:
  4644     (asm_)(full_)simplify: simpset -> thm -> thm;
  4645 
  4646 * simplifier.ML no longer part of Pure -- has to be loaded by object
  4647 logics (again);
  4648 
  4649 * added prems argument to simplification procedures;
  4650 
  4651 * HOL, FOL, ZF: added infix function `addsplits':
  4652   instead of `<simpset> setloop (split_tac <thms>)'
  4653   you can simply write `<simpset> addsplits <thms>'
  4654 
  4655 
  4656 *** Syntax ***
  4657 
  4658 * TYPE('a) syntax for type reflection terms;
  4659 
  4660 * no longer handles consts with name "" -- declare as 'syntax' instead;
  4661 
  4662 * pretty printer: changed order of mixfix annotation preference (again!);
  4663 
  4664 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  4665 
  4666 
  4667 *** HOL ***
  4668 
  4669 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4670   with `addloop' of the simplifier to faciliate case splitting in premises.
  4671 
  4672 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  4673 
  4674 * HOL/Auth: new protocol proofs including some for the Internet
  4675   protocol TLS;
  4676 
  4677 * HOL/Map: new theory of `maps' a la VDM;
  4678 
  4679 * HOL/simplifier: simplification procedures nat_cancel_sums for
  4680 cancelling out common nat summands from =, <, <= (in)equalities, or
  4681 differences; simplification procedures nat_cancel_factor for
  4682 cancelling common factor from =, <, <= (in)equalities over natural
  4683 sums; nat_cancel contains both kinds of procedures, it is installed by
  4684 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  4685 
  4686 * HOL/simplifier: terms of the form
  4687   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  4688   are rewritten to
  4689   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  4690   and those of the form
  4691   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  4692   are rewritten to
  4693   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  4694 
  4695 * HOL/datatype
  4696   Each datatype `t' now comes with a theorem `split_t_case' of the form
  4697 
  4698   P(t_case f1 ... fn x) =
  4699      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  4700         ...
  4701        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  4702      )
  4703 
  4704   and a theorem `split_t_case_asm' of the form
  4705 
  4706   P(t_case f1 ... fn x) =
  4707     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  4708         ...
  4709        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  4710      )
  4711   which can be added to a simpset via `addsplits'. The existing theorems
  4712   expand_list_case and expand_option_case have been renamed to
  4713   split_list_case and split_option_case.
  4714 
  4715 * HOL/Arithmetic:
  4716   - `pred n' is automatically converted to `n-1'.
  4717     Users are strongly encouraged not to use `pred' any longer,
  4718     because it will disappear altogether at some point.
  4719   - Users are strongly encouraged to write "0 < n" rather than
  4720     "n ~= 0". Theorems and proof tools have been modified towards this
  4721     `standard'.
  4722 
  4723 * HOL/Lists:
  4724   the function "set_of_list" has been renamed "set" (and its theorems too);
  4725   the function "nth" now takes its arguments in the reverse order and
  4726   has acquired the infix notation "!" as in "xs!n".
  4727 
  4728 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  4729 
  4730 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  4731   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  4732 
  4733 * HOL/record: extensible records with schematic structural subtyping
  4734 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  4735 still lacks various theorems and concrete record syntax;
  4736 
  4737 
  4738 *** HOLCF ***
  4739 
  4740 * removed "axioms" and "generated by" sections;
  4741 
  4742 * replaced "ops" section by extended "consts" section, which is capable of
  4743   handling the continuous function space "->" directly;
  4744 
  4745 * domain package:
  4746   . proves theorems immediately and stores them in the theory,
  4747   . creates hierachical name space,
  4748   . now uses normal mixfix annotations (instead of cinfix...),
  4749   . minor changes to some names and values (for consistency),
  4750   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  4751   . separator between mutual domain defs: changed "," to "and",
  4752   . improved handling of sort constraints;  now they have to
  4753     appear on the left-hand side of the equations only;
  4754 
  4755 * fixed LAM <x,y,zs>.b syntax;
  4756 
  4757 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  4758 adm (%x. P (t x)), where P is chainfinite and t continuous;
  4759 
  4760 
  4761 *** FOL and ZF ***
  4762 
  4763 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4764   with `addloop' of the simplifier to faciliate case splitting in premises.
  4765 
  4766 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  4767 in HOL, they strip ALL and --> from proved theorems;
  4768 
  4769 
  4770 
  4771 New in Isabelle94-8 (May 1997)
  4772 ------------------------------
  4773 
  4774 *** General Changes ***
  4775 
  4776 * new utilities to build / run / maintain Isabelle etc. (in parts
  4777 still somewhat experimental); old Makefiles etc. still functional;
  4778 
  4779 * new 'Isabelle System Manual';
  4780 
  4781 * INSTALL text, together with ./configure and ./build scripts;
  4782 
  4783 * reimplemented type inference for greater efficiency, better error
  4784 messages and clean internal interface;
  4785 
  4786 * prlim command for dealing with lots of subgoals (an easier way of
  4787 setting goals_limit);
  4788 
  4789 
  4790 *** Syntax ***
  4791 
  4792 * supports alternative (named) syntax tables (parser and pretty
  4793 printer); internal interface is provided by add_modesyntax(_i);
  4794 
  4795 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  4796 be used in conjunction with the Isabelle symbol font; uses the
  4797 "symbols" syntax table;
  4798 
  4799 * added token_translation interface (may translate name tokens in
  4800 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  4801 the current print_mode); IMPORTANT: user print translation functions
  4802 are responsible for marking newly introduced bounds
  4803 (Syntax.mark_boundT);
  4804 
  4805 * token translations for modes "xterm" and "xterm_color" that display
  4806 names in bold, underline etc. or colors (which requires a color
  4807 version of xterm);
  4808 
  4809 * infixes may now be declared with names independent of their syntax;
  4810 
  4811 * added typed_print_translation (like print_translation, but may
  4812 access type of constant);
  4813 
  4814 
  4815 *** Classical Reasoner ***
  4816 
  4817 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  4818 some limitations.  Blast_tac...
  4819   + ignores addss, addbefore, addafter; this restriction is intrinsic
  4820   + ignores elimination rules that don't have the correct format
  4821         (the conclusion MUST be a formula variable)
  4822   + ignores types, which can make HOL proofs fail
  4823   + rules must not require higher-order unification, e.g. apply_type in ZF
  4824     [message "Function Var's argument not a bound variable" relates to this]
  4825   + its proof strategy is more general but can actually be slower
  4826 
  4827 * substitution with equality assumptions no longer permutes other
  4828 assumptions;
  4829 
  4830 * minor changes in semantics of addafter (now called addaltern); renamed
  4831 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  4832 (and access functions for it);
  4833 
  4834 * improved combination of classical reasoner and simplifier:
  4835   + functions for handling clasimpsets
  4836   + improvement of addss: now the simplifier is called _after_ the
  4837     safe steps.
  4838   + safe variant of addss called addSss: uses safe simplifications
  4839     _during_ the safe steps. It is more complete as it allows multiple
  4840     instantiations of unknowns (e.g. with slow_tac).
  4841 
  4842 *** Simplifier ***
  4843 
  4844 * added interface for simplification procedures (functions that
  4845 produce *proven* rewrite rules on the fly, depending on current
  4846 redex);
  4847 
  4848 * ordering on terms as parameter (used for ordered rewriting);
  4849 
  4850 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  4851 
  4852 * the solver is now split into a safe and an unsafe part.
  4853 This should be invisible for the normal user, except that the
  4854 functions setsolver and addsolver have been renamed to setSolver and
  4855 addSolver; added safe_asm_full_simp_tac;
  4856 
  4857 
  4858 *** HOL ***
  4859 
  4860 * a generic induction tactic `induct_tac' which works for all datatypes and
  4861 also for type `nat';
  4862 
  4863 * a generic case distinction tactic `exhaust_tac' which works for all
  4864 datatypes and also for type `nat';
  4865 
  4866 * each datatype comes with a function `size';
  4867 
  4868 * patterns in case expressions allow tuple patterns as arguments to
  4869 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  4870 
  4871 * primrec now also works with type nat;
  4872 
  4873 * recdef: a new declaration form, allows general recursive functions to be
  4874 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  4875 
  4876 * the constant for negation has been renamed from "not" to "Not" to
  4877 harmonize with FOL, ZF, LK, etc.;
  4878 
  4879 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  4880 infinite lists;
  4881 
  4882 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  4883 
  4884 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  4885 problems in commutative rings, using axiomatic type classes for + and *;
  4886 
  4887 * more examples in HOL/MiniML and HOL/Auth;
  4888 
  4889 * more default rewrite rules for quantifiers, union/intersection;
  4890 
  4891 * a new constant `arbitrary == @x.False';
  4892 
  4893 * HOLCF/IOA replaces old HOL/IOA;
  4894 
  4895 * HOLCF changes: derived all rules and arities
  4896   + axiomatic type classes instead of classes
  4897   + typedef instead of faking type definitions
  4898   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  4899   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  4900   + eliminated the types void, one, tr
  4901   + use unit lift and bool lift (with translations) instead of one and tr
  4902   + eliminated blift from Lift3.thy (use Def instead of blift)
  4903   all eliminated rules are derived as theorems --> no visible changes ;
  4904 
  4905 
  4906 *** ZF ***
  4907 
  4908 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  4909 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  4910 as ZF_cs addSIs [equalityI];
  4911 
  4912 
  4913 
  4914 New in Isabelle94-7 (November 96)
  4915 ---------------------------------
  4916 
  4917 * allowing negative levels (as offsets) in prlev and choplev;
  4918 
  4919 * super-linear speedup for large simplifications;
  4920 
  4921 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  4922 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  4923 FAIL); can suppress it using the command Delsimps (ex_simps @
  4924 all_simps); De Morgan laws are also now included, by default;
  4925 
  4926 * improved printing of ==>  :  ~:
  4927 
  4928 * new object-logic "Sequents" adds linear logic, while replacing LK
  4929 and Modal (thanks to Sara Kalvala);
  4930 
  4931 * HOL/Auth: correctness proofs for authentication protocols;
  4932 
  4933 * HOL: new auto_tac combines rewriting and classical reasoning (many
  4934 examples on HOL/Auth);
  4935 
  4936 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  4937 the rewriter and classical reasoner simultaneously;
  4938 
  4939 * function uresult no longer returns theorems in "standard" format;
  4940 regain previous version by: val uresult = standard o uresult;
  4941 
  4942 
  4943 
  4944 New in Isabelle94-6
  4945 -------------------
  4946 
  4947 * oracles -- these establish an interface between Isabelle and trusted
  4948 external reasoners, which may deliver results as theorems;
  4949 
  4950 * proof objects (in particular record all uses of oracles);
  4951 
  4952 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  4953 
  4954 * "constdefs" section in theory files;
  4955 
  4956 * "primrec" section (HOL) no longer requires names;
  4957 
  4958 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  4959 
  4960 
  4961 
  4962 New in Isabelle94-5
  4963 -------------------
  4964 
  4965 * reduced space requirements;
  4966 
  4967 * automatic HTML generation from theories;
  4968 
  4969 * theory files no longer require "..." (quotes) around most types;
  4970 
  4971 * new examples, including two proofs of the Church-Rosser theorem;
  4972 
  4973 * non-curried (1994) version of HOL is no longer distributed;
  4974 
  4975 
  4976 
  4977 New in Isabelle94-4
  4978 -------------------
  4979 
  4980 * greatly reduced space requirements;
  4981 
  4982 * theory files (.thy) no longer require \...\ escapes at line breaks;
  4983 
  4984 * searchable theorem database (see the section "Retrieving theorems" on
  4985 page 8 of the Reference Manual);
  4986 
  4987 * new examples, including Grabczewski's monumental case study of the
  4988 Axiom of Choice;
  4989 
  4990 * The previous version of HOL renamed to Old_HOL;
  4991 
  4992 * The new version of HOL (previously called CHOL) uses a curried syntax
  4993 for functions.  Application looks like f a b instead of f(a,b);
  4994 
  4995 * Mutually recursive inductive definitions finally work in HOL;
  4996 
  4997 * In ZF, pattern-matching on tuples is now available in all abstractions and
  4998 translates to the operator "split";
  4999 
  5000 
  5001 
  5002 New in Isabelle94-3
  5003 -------------------
  5004 
  5005 * new infix operator, addss, allowing the classical reasoner to
  5006 perform simplification at each step of its search.  Example:
  5007         fast_tac (cs addss ss)
  5008 
  5009 * a new logic, CHOL, the same as HOL, but with a curried syntax
  5010 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  5011 look like (a,b) instead of <a,b>;
  5012 
  5013 * PLEASE NOTE: CHOL will eventually replace HOL!
  5014 
  5015 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  5016 It translates to the operator "split".  A new theory of integers is available;
  5017 
  5018 * In ZF, integer numerals now denote two's-complement binary integers.
  5019 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  5020 
  5021 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  5022 of the Axiom of Choice;
  5023 
  5024 
  5025 
  5026 New in Isabelle94-2
  5027 -------------------
  5028 
  5029 * Significantly faster resolution;
  5030 
  5031 * the different sections in a .thy file can now be mixed and repeated
  5032 freely;
  5033 
  5034 * Database of theorems for FOL, HOL and ZF.  New
  5035 commands including qed, qed_goal and bind_thm store theorems in the database.
  5036 
  5037 * Simple database queries: return a named theorem (get_thm) or all theorems of
  5038 a given theory (thms_of), or find out what theory a theorem was proved in
  5039 (theory_of_thm);
  5040 
  5041 * Bugs fixed in the inductive definition and datatype packages;
  5042 
  5043 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  5044 and HOL_dup_cs obsolete;
  5045 
  5046 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  5047 have been removed;
  5048 
  5049 * Simpler definition of function space in ZF;
  5050 
  5051 * new results about cardinal and ordinal arithmetic in ZF;
  5052 
  5053 * 'subtype' facility in HOL for introducing new types as subsets of existing
  5054 types;
  5055 
  5056 :mode=text:wrap=hard:maxLineLen=72:
  5057 $Id$