NEWS
author wenzelm
Tue Oct 16 18:34:51 2007 +0200 (2007-10-16)
changeset 25057 021fcbe2aaa5
parent 25034 7f2e1a8e181b
child 25062 af5ef0d4d655
permissions -rw-r--r--
Mark A. Hillebrand, DFKI: Robust sub/superscripts in LaTeX document output.
     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 * Code generator: consts in 'consts_code' Isar commands are now
   113 referred to by usual term syntax (including optional type
   114 annotations).
   115 
   116 * Code generator: basic definitions (from 'definition', 'constdefs',
   117 or primitive 'instance' definitions) are added automatically to the
   118 table of defining equations.  Primitive defs are not used as defining
   119 equations by default any longer.  defining equations are now definitly
   120 restricted to meta "==" and object equality "=".
   121 
   122 * The 'class' package offers a combination of axclass and locale to
   123 achieve Haskell-like type classes in Isabelle.  See
   124 HOL/ex/Classpackage.thy for examples.
   125 
   126 * Yet another code generator framework allows to generate executable
   127 code for ML and Haskell (including Isabelle classes).  A short usage
   128 sketch:
   129 
   130     internal compilation:
   131         code_gen <list of constants (term syntax)> in SML
   132     writing SML code to a file:
   133         code_gen <list of constants (term syntax)> in SML <filename>
   134     writing OCaml code to a file:
   135         code_gen <list of constants (term syntax)> in OCaml <filename>
   136     writing Haskell code to a bunch of files:
   137         code_gen <list of constants (term syntax)> in Haskell <filename>
   138 
   139 Reasonable default setup of framework in HOL/Main.
   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 apply to target Haskell.
   165 
   166 For example usage see HOL/ex/Codegenerator.thy and
   167 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 * Command 'no_translations' removes translation rules from theory
   172 syntax.
   173 
   174 * Overloaded definitions are now actually checked for acyclic
   175 dependencies.  The overloading scheme is slightly more general than
   176 that of Haskell98, although Isabelle does not demand an exact
   177 correspondence to type class and instance declarations.
   178 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
   179 exotic versions of overloading -- at the discretion of the user!
   180 
   181 Polymorphic constants are represented via type arguments, i.e. the
   182 instantiation that matches an instance against the most general
   183 declaration given in the signature.  For example, with the declaration
   184 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
   185 as c(nat).  Overloading is essentially simultaneous structural
   186 recursion over such type arguments.  Incomplete specification patterns
   187 impose global constraints on all occurrences, e.g. c('a * 'a) on the
   188 LHS means that more general c('a * 'b) will be disallowed on any RHS.
   189 Command 'print_theory' outputs the normalized system of recursive
   190 equations, see section "definitions".
   191 
   192 * Configuration options are maintained within the theory or proof
   193 context (with name and type bool/int/string), providing a very simple
   194 interface to a poor-man's version of general context data.  Tools may
   195 declare options in ML (e.g. using Attrib.config_int) and then refer to
   196 these values using Config.get etc.  Users may change options via an
   197 associated attribute of the same name.  This form of context
   198 declaration works particularly well with commands 'declare' or
   199 'using', for example ``declare [[foo = 42]]''.  Thus it has become
   200 very easy to avoid global references, which would not observe Isar
   201 toplevel undo/redo and fail to work with multithreading.
   202 
   203 Various global ML references of Pure and HOL have been turned into
   204 configuration options:
   205 
   206   Unify.search_bound		unify_search_bound
   207   Unify.trace_bound		unify_trace_bound
   208   Unify.trace_simp		unify_trace_simp
   209   Unify.trace_types		unify_trace_types
   210   Simplifier.simp_depth_limit	simp_depth_limit
   211   Blast.depth_limit		blast_depth_limit
   212   DatatypeProp.dtK		datatype_distinctness_limit
   213   fast_arith_neq_limit  	fast_arith_neq_limit
   214   fast_arith_split_limit	fast_arith_split_limit
   215 
   216 * Named collections of theorems may be easily installed as context
   217 data using the functor NamedThmsFun (see also
   218 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
   219 attributes; there is also a toplevel print command.  This facility is
   220 just a common case of general context data, which is the preferred way
   221 for anything more complex than just a list of facts in canonical
   222 order.
   223 
   224 * Isar: command 'declaration' augments a local theory by generic
   225 declaration functions written in ML.  This enables arbitrary content
   226 being added to the context, depending on a morphism that tells the
   227 difference of the original declaration context wrt. the application
   228 context encountered later on.
   229 
   230 * Isar: proper interfaces for simplification procedures.  Command
   231 'simproc_setup' declares named simprocs (with match patterns, and body
   232 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
   233 context.  ML antiquotation @{simproc name} retrieves named simprocs.
   234 
   235 * Isar: an extra pair of brackets around attribute declarations
   236 abbreviates a theorem reference involving an internal dummy fact,
   237 which will be ignored later --- only the effect of the attribute on
   238 the background context will persist.  This form of in-place
   239 declarations is particularly useful with commands like 'declare' and
   240 'using', for example ``have A using [[simproc a]] by simp''.
   241 
   242 * Isar: method "assumption" (and implicit closing of subproofs) now
   243 takes simple non-atomic goal assumptions into account: after applying
   244 an assumption as a rule the resulting subgoals are solved by atomic
   245 assumption steps.  This is particularly useful to finish 'obtain'
   246 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
   247 without referring to the original premise "!!x. P x ==> thesis" in the
   248 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
   249 more permissive.
   250 
   251 * Isar: implicit use of prems from the Isar proof context is
   252 considered a legacy feature.  Common applications like ``have A .''
   253 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
   254 referencing facts explicitly here improves readability and
   255 maintainability of proof texts.
   256 
   257 * Isar: improper proof element 'guess' is like 'obtain', but derives
   258 the obtained context from the course of reasoning!  For example:
   259 
   260   assume "EX x y. A x & B y"   -- "any previous fact"
   261   then guess x and y by clarify
   262 
   263 This technique is potentially adventurous, depending on the facts and
   264 proof tools being involved here.
   265 
   266 * Isar: known facts from the proof context may be specified as literal
   267 propositions, using ASCII back-quote syntax.  This works wherever
   268 named facts used to be allowed so far, in proof commands, proof
   269 methods, attributes etc.  Literal facts are retrieved from the context
   270 according to unification of type and term parameters.  For example,
   271 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
   272 theorems in the current context, then these are valid literal facts:
   273 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
   274 
   275 There is also a proof method "fact" which does the same composition
   276 for explicit goal states, e.g. the following proof texts coincide with
   277 certain special cases of literal facts:
   278 
   279   have "A" by fact                 ==  note `A`
   280   have "A ==> B" by fact           ==  note `A ==> B`
   281   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
   282   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
   283 
   284 * Isar: ":" (colon) is no longer a symbolic identifier character in
   285 outer syntax.  Thus symbolic identifiers may be used without
   286 additional white space in declarations like this: ``assume *: A''.
   287 
   288 * Isar: 'print_facts' prints all local facts of the current context,
   289 both named and unnamed ones.
   290 
   291 * Isar: 'def' now admits simultaneous definitions, e.g.:
   292 
   293   def x == "t" and y == "u"
   294 
   295 * Isar: added command 'unfolding', which is structurally similar to
   296 'using', but affects both the goal state and facts by unfolding given
   297 rewrite rules.  Thus many occurrences of the 'unfold' method or
   298 'unfolded' attribute may be replaced by first-class proof text.
   299 
   300 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
   301 and command 'unfolding' now all support object-level equalities
   302 (potentially conditional).  The underlying notion of rewrite rule is
   303 analogous to the 'rule_format' attribute, but *not* that of the
   304 Simplifier (which is usually more generous).
   305 
   306 * Isar: the new attribute [rotated n] (default n = 1) rotates the
   307 premises of a theorem by n. Useful in conjunction with drule.
   308 
   309 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
   310 method expression within a sandbox consisting of the first N
   311 sub-goals, which need to exist.  For example, ``simp_all [3]''
   312 simplifies the first three sub-goals, while (rule foo, simp_all)[]
   313 simplifies all new goals that emerge from applying rule foo to the
   314 originally first one.
   315 
   316 * Isar: schematic goals are no longer restricted to higher-order
   317 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
   318 expected.
   319 
   320 * Isar: the conclusion of a long theorem statement is now either
   321 'shows' (a simultaneous conjunction, as before), or 'obtains'
   322 (essentially a disjunction of cases with local parameters and
   323 assumptions).  The latter allows to express general elimination rules
   324 adequately; in this notation common elimination rules look like this:
   325 
   326   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
   327     assumes "EX x. P x"
   328     obtains x where "P x"
   329 
   330   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
   331     assumes "A & B"
   332     obtains A and B
   333 
   334   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
   335     assumes "A | B"
   336     obtains
   337       A
   338     | B
   339 
   340 The subsequent classical rules even refer to the formal "thesis"
   341 explicitly:
   342 
   343   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
   344     obtains "~ thesis"
   345 
   346   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
   347     obtains "thesis ==> something"
   348 
   349 The actual proof of an 'obtains' statement is analogous to that of the
   350 Isar proof element 'obtain', only that there may be several cases.
   351 Optional case names may be specified in parentheses; these will be
   352 available both in the present proof and as annotations in the
   353 resulting rule, for later use with the 'cases' method (cf. attribute
   354 case_names).
   355 
   356 * Isar: the assumptions of a long theorem statement are available as
   357 "assms" fact in the proof context.  This is more appropriate than the
   358 (historical) "prems", which refers to all assumptions of the current
   359 context, including those from the target locale, proof body etc.
   360 
   361 * Isar: 'print_statement' prints theorems from the current theory or
   362 proof context in long statement form, according to the syntax of a
   363 top-level lemma.
   364 
   365 * Isar: 'obtain' takes an optional case name for the local context
   366 introduction rule (default "that").
   367 
   368 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
   369 explicit (is "_ ==> ?foo") in the rare cases where this still happens
   370 to occur.
   371 
   372 * Pure: syntax "CONST name" produces a fully internalized constant
   373 according to the current context.  This is particularly useful for
   374 syntax translations that should refer to internal constant
   375 representations independently of name spaces.
   376 
   377 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
   378 instead of "FOO ". This allows multiple binder declarations to coexist
   379 in the same context.  INCOMPATIBILITY.
   380 
   381 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
   382 primitive that also works in a locale context (both for constants and
   383 fixed variables). Type declaration and internal syntactic representation
   384 of given constants retrieved from the context. Likewise, the
   385 'no_notation' command allows to remove given syntax annotations from the
   386 current context.
   387 
   388 * Isar/locales: new derived specification elements 'axiomatization',
   389 'definition', 'abbreviation', which support type-inference, admit
   390 object-level specifications (equality, equivalence).  See also the
   391 isar-ref manual.  Examples:
   392 
   393   axiomatization
   394     eq  (infix "===" 50) where
   395     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
   396 
   397   definition "f x y = x + y + 1"
   398   definition g where "g x = f x x"
   399 
   400   abbreviation
   401     neq  (infix "=!=" 50) where
   402     "x =!= y == ~ (x === y)"
   403 
   404 These specifications may be also used in a locale context.  Then the
   405 constants being introduced depend on certain fixed parameters, and the
   406 constant name is qualified by the locale base name.  An internal
   407 abbreviation takes care for convenient input and output, making the
   408 parameters implicit and using the original short name.  See also
   409 HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
   410 entities from a monomorphic theory.
   411 
   412 Presently, abbreviations are only available 'in' a target locale, but
   413 not inherited by general import expressions.  Also note that
   414 'abbreviation' may be used as a type-safe replacement for 'syntax' +
   415 'translations' in common applications.  The "no_abbrevs" print mode
   416 prevents folding of abbreviations in term output.
   417 
   418 Concrete syntax is attached to specified constants in internal form,
   419 independently of name spaces.  The parse tree representation is
   420 slightly different -- use 'notation' instead of raw 'syntax', and
   421 'translations' with explicit "CONST" markup to accommodate this.
   422 
   423 * Pure/Isar: unified syntax for new-style specification mechanisms
   424 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
   425 full type inference and dummy patterns ("_").  For example:
   426 
   427   definition "K x _ = x"
   428 
   429   inductive conj for A B
   430   where "A ==> B ==> conj A B"
   431 
   432 * Pure: command 'print_abbrevs' prints all constant abbreviations of
   433 the current context.  Print mode "no_abbrevs" prevents inversion of
   434 abbreviations on output.
   435 
   436 * Isar/locales: improved parameter handling: use of locales "var" and
   437 "struct" no longer necessary; - parameter renamings are no longer
   438 required to be injective.  For example, this allows to define
   439 endomorphisms as locale endom = homom mult mult h.
   440 
   441 * Isar/locales: changed the way locales with predicates are defined.
   442 Instead of accumulating the specification, the imported expression is
   443 now an interpretation.  INCOMPATIBILITY: different normal form of
   444 locale expressions.  In particular, in interpretations of locales with
   445 predicates, goals repesenting already interpreted fragments are not
   446 removed automatically.  Use methods `intro_locales' and
   447 `unfold_locales'; see below.
   448 
   449 * Isar/locales: new methods `intro_locales' and `unfold_locales'
   450 provide backward reasoning on locales predicates.  The methods are
   451 aware of interpretations and discharge corresponding goals.
   452 `intro_locales' is less aggressive then `unfold_locales' and does not
   453 unfold predicates to assumptions.
   454 
   455 * Isar/locales: the order in which locale fragments are accumulated
   456 has changed.  This enables to override declarations from fragments due
   457 to interpretations -- for example, unwanted simp rules.
   458 
   459 * Isar/locales: interpretation in theories and proof contexts has been
   460 extended.  One may now specify (and prove) equations, which are
   461 unfolded in interpreted theorems.  This is useful for replacing
   462 defined concepts (constants depending on locale parameters) by
   463 concepts already existing in the target context.  Example:
   464 
   465   interpretation partial_order ["op <= :: [int, int] => bool"]
   466     where "partial_order.less (op <=) (x::int) y = (x < y)"
   467 
   468 Typically, the constant `partial_order.less' is created by a
   469 definition specification element in the context of locale
   470 partial_order.
   471 
   472 * Method "induct": improved internal context management to support
   473 local fixes and defines on-the-fly. Thus explicit meta-level
   474 connectives !!  and ==> are rarely required anymore in inductive goals
   475 (using object-logic connectives for this purpose has been long
   476 obsolete anyway). Common proof patterns are explained in
   477 HOL/Induct/Common_Patterns.thy, see also HOL/Isar_examples/Puzzle.thy
   478 and src/HOL/Lambda for realistic examples.
   479 
   480 * Method "induct": improved handling of simultaneous goals. Instead of
   481 introducing object-level conjunction, the statement is now split into
   482 several conclusions, while the corresponding symbolic cases are nested
   483 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
   484 see HOL/Induct/Common_Patterns.thy, for example.
   485 
   486 * Method "induct": mutual induction rules are now specified as a list
   487 of rule sharing the same induction cases. HOL packages usually provide
   488 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
   489 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
   490 mutual induction rules differently, i.e. like this:
   491 
   492   (induct rule: foo_bar.inducts)
   493   (induct set: foo bar)
   494   (induct pred: foo bar)
   495   (induct type: foo bar)
   496 
   497 The ML function ProjectRule.projections turns old-style rules into the
   498 new format.
   499 
   500 * Method "coinduct": dual of induction, see
   501 src/HOL/Library/Coinductive_List.thy for various examples.
   502 
   503 * Method "cases", "induct", "coinduct": the ``(open)'' option is
   504 considered a legacy feature.
   505 
   506 * Attribute "symmetric" produces result with standardized schematic
   507 variables (index 0).  Potential INCOMPATIBILITY.
   508 
   509 * Simplifier: by default the simplifier trace only shows top level
   510 rewrites now. That is, trace_simp_depth_limit is set to 1 by
   511 default. Thus there is less danger of being flooded by the trace. The
   512 trace indicates where parts have been suppressed.
   513   
   514 * Provers/classical: removed obsolete classical version of elim_format
   515 attribute; classical elim/dest rules are now treated uniformly when
   516 manipulating the claset.
   517 
   518 * Provers/classical: stricter checks to ensure that supplied intro,
   519 dest and elim rules are well-formed; dest and elim rules must have at
   520 least one premise.
   521 
   522 * Provers/classical: attributes dest/elim/intro take an optional
   523 weight argument for the rule (just as the Pure versions).  Weights are
   524 ignored by automated tools, but determine the search order of single
   525 rule steps.
   526 
   527 * Syntax: input syntax now supports dummy variable binding "%_. b",
   528 where the body does not mention the bound variable.  Note that dummy
   529 patterns implicitly depend on their context of bounds, which makes
   530 "{_. _}" match any set comprehension as expected.  Potential
   531 INCOMPATIBILITY -- parse translations need to cope with syntactic
   532 constant "_idtdummy" in the binding position.
   533 
   534 * Syntax: removed obsolete syntactic constant "_K" and its associated
   535 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
   536 for example "A -> B" => "Pi A (%_. B)".
   537 
   538 * Pure: 'class_deps' command visualizes the subclass relation, using
   539 the graph browser tool.
   540 
   541 * Pure: 'print_theory' now suppresses certain internal declarations by
   542 default; use '!' option for full details.
   543 
   544 
   545 *** HOL ***
   546 
   547 * class "div" now inherits from class "times" rather than "type".
   548 INCOMPATIBILITY.
   549 
   550 * New "auto_quickcheck" feature tests outermost goal statements for
   551 potential counter-examples.  Controlled by ML references
   552 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
   553 5000 milliseconds).
   554 
   555 * Internal reorganisation of `size' of datatypes: size theorems
   556 "foo.size" are no longer subsumed by "foo.simps" (but are still
   557 simplification rules by default!); theorems "prod.size" now named
   558 "*.size"
   559 
   560 * The transitivity reasoner for partial and linear orders is set up
   561 for locales "order" and "linorder" generated by the new class package
   562 (instead of axiomatic type classes used before).  Instances of the
   563 reasoner are available in all contexts importing or interpreting these
   564 locales.  Method "order" invokes the reasoner separately; the reasoner
   565 is also integrated with the Simplifier as a solver.  Diagnostic
   566 command 'print_orders' shows the available instances of the reasoner
   567 in the current context.
   568 
   569 * Formulation of theorem "dense" changed slightly due to integration
   570 with new class dense_linear_order.
   571 
   572 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
   573 Linorder etc.  have disappeared; operations defined in terms of
   574 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
   575 
   576 * HOL-Word: New extensive library and type for generic, fixed size
   577 machine words, with arithemtic, bit-wise, shifting and rotating
   578 operations, reflection into int, nat, and bool lists, automation for
   579 linear arithmetic (by automatic reflection into nat or int), including
   580 lemmas on overflow and monotonicity.  Instantiated to all appropriate
   581 arithmetic type classes, supporting automatic simplification of
   582 numerals on all operations.
   583 
   584 * Library/Boolean_Algebra: locales for abstract boolean algebras.
   585 
   586 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
   587 
   588 * Code generator library theories:
   589   - Code_Integer represents HOL integers by big integer literals in target
   590     languages.
   591   - Code_Char represents HOL characters by character literals in target
   592     languages.
   593   - Code_Char_chr like Code_Char, but also offers treatment of character
   594     codes; includes Code_Integer.
   595   - Executable_Set allows to generate code for finite sets using lists.
   596   - Executable_Rat implements rational numbers as triples (sign, enumerator,
   597     denominator).
   598   - Executable_Real implements a subset of real numbers, namly those
   599     representable by rational numbers.
   600   - Efficient_Nat implements natural numbers by integers, which in general will
   601     result in higher efficency; pattern matching with 0/Suc is eliminated;
   602     includes Code_Integer.
   603   - Code_Index provides an additional datatype index which is mapped to
   604     target-language built-in integers.
   605   - Code_Message provides an additional datatype message_string} which is isomorphic to
   606     strings; messages are mapped to target-language strings.
   607 
   608 * New package for inductive predicates
   609 
   610   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
   611 
   612     inductive
   613       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
   614       for z_1 :: U_1 and ... and z_n :: U_m
   615     where
   616       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
   617     | ...
   618 
   619   with full support for type-inference, rather than
   620 
   621     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
   622 
   623     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
   624     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
   625 
   626     inductive "s z_1 ... z_m"
   627     intros
   628       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
   629       ...
   630 
   631   For backward compatibility, there is a wrapper allowing inductive
   632   sets to be defined with the new package via
   633 
   634     inductive_set
   635       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
   636       for z_1 :: U_1 and ... and z_n :: U_m
   637     where
   638       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
   639     | ...
   640 
   641   or
   642 
   643     inductive_set
   644       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
   645       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
   646       for z_1 :: U_1 and ... and z_n :: U_m
   647     where
   648       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
   649     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
   650     | ...
   651 
   652   if the additional syntax "p ..." is required.
   653 
   654   Numerous examples can be found in the subdirectories HOL/Auth, HOL/Bali,
   655   HOL/Induct, and HOL/MicroJava.
   656 
   657   INCOMPATIBILITIES:
   658 
   659   - Since declaration and definition of inductive sets or predicates
   660     is no longer separated, abbreviations involving the newly
   661     introduced sets or predicates must be specified together with the
   662     introduction rules after the 'where' keyword (see above), rather
   663     than before the actual inductive definition.
   664 
   665   - The variables in induction and elimination rules are now
   666     quantified in the order of their occurrence in the introduction
   667     rules, rather than in alphabetical order. Since this may break
   668     some proofs, these proofs either have to be repaired, e.g. by
   669     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
   670     statements of the form
   671 
   672       case (rule_i a_i_1 ... a_i_{k_i})
   673 
   674     or the old order of quantification has to be restored by explicitly adding
   675     meta-level quantifiers in the introduction rules, i.e.
   676 
   677       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
   678 
   679   - The format of the elimination rules is now
   680 
   681       p z_1 ... z_m x_1 ... x_n ==>
   682         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
   683         ==> ... ==> P
   684 
   685     for predicates and
   686 
   687       (x_1, ..., x_n) : s z_1 ... z_m ==>
   688         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
   689         ==> ... ==> P
   690 
   691     for sets rather than
   692 
   693       x : s z_1 ... z_m ==>
   694         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
   695         ==> ... ==> P
   696 
   697     This may require terms in goals to be expanded to n-tuples
   698     (e.g. using case_tac or simplification with the split_paired_all
   699     rule) before the above elimination rule is applicable.
   700 
   701   - The elimination or case analysis rules for (mutually) inductive
   702     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
   703     list of rules "p_1_..._p_k.elims" is no longer available.
   704 
   705 * Method "metis" proves goals by applying the Metis general-purpose
   706 resolution prover.  Examples are in the directory MetisExamples.  See
   707 also http://gilith.com/software/metis/
   708 
   709 WARNING: the Isabelle/HOL-Metis integration does not yet work properly
   710 with multi-threading.
   711   
   712 * Command 'sledgehammer' invokes external automatic theorem provers as
   713 background processes.  It generates calls to the "metis" method if
   714 successful. These can be pasted into the proof.  Users do not have to
   715 wait for the automatic provers to return.
   716 
   717 * Case-expressions allow arbitrary constructor-patterns (including
   718 "_") and take their order into account, like in functional
   719 programming.  Internally, this is translated into nested
   720 case-expressions; missing cases are added and mapped to the predefined
   721 constant "undefined". In complicated cases printing may no longer show
   722 the original input but the internal form. Lambda-abstractions allow
   723 the same form of pattern matching: "% pat1 => e1 | ..." is an
   724 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
   725 variable.
   726 
   727 * IntDef: The constant "int :: nat => int" has been removed; now "int"
   728 is an abbreviation for "of_nat :: nat => int". The simplification
   729 rules for "of_nat" have been changed to work like "int" did
   730 previously.  Potential INCOMPATIBILITY:
   731   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
   732   - of_nat_diff and of_nat_mult are no longer default simp rules
   733 
   734 * Method "algebra" solves polynomial equations over (semi)rings using
   735 Groebner bases. The (semi)ring structure is defined by locales and the
   736 tool setup depends on that generic context. Installing the method for
   737 a specific type involves instantiating the locale and possibly adding
   738 declarations for computation on the coefficients.  The method is
   739 already instantiated for natural numbers and for the axiomatic class
   740 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
   741 CALCULEMUS 2007 for the general principles underlying this
   742 architecture of context-aware proof-tools.
   743 
   744 * Method "ferrack" implements quantifier elimination over
   745 special-purpose dense linear orders using locales (analogous to
   746 "algebra"). The method is already installed for class
   747 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
   748 rat, etc.
   749 
   750 * Former constant "List.op @" now named "List.append".  Use ML
   751 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
   752 circumvent possible incompatibilities when working on ML level.
   753 
   754 * Some renaming of class constants due to canonical name prefixing in
   755 the new 'class' package:
   756 
   757     HOL.abs ~> HOL.minus_class.abs
   758     HOL.divide ~> HOL.divide_class.divide
   759     Nat.power ~> Power.power_class.power
   760     Nat.size ~> Nat.size_class.size
   761     Numeral.number_of ~> Numeral.number_class.number_of
   762     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
   763     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
   764     Orderings.min ~> Orderings.ord_class.min
   765     Orderings.max ~> Orderings.ord_class.max
   766 
   767 INCOMPATIBILITY.
   768 
   769 * New class "default" with associated constant "default".
   770 
   771 * New constant "undefined" with axiom "undefined x = undefined".
   772 
   773 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
   774 
   775 * New function listsum :: 'a list => 'a for arbitrary monoids.
   776 Special syntax: "SUM x <- xs. f x" (and latex variants)
   777 
   778 * New syntax for Haskell-like list comprehension (input only), eg.
   779 [(x,y). x <- xs, y <- ys, x ~= y], see also HOL/List.thy.
   780 
   781 * The special syntax for function "filter" has changed from [x :
   782 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
   783 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
   784 
   785 * [a..b] is now defined for arbitrary linear orders.  It used to be
   786 defined on nat only, as an abbreviation for [a..<Suc b]
   787 INCOMPATIBILITY.
   788 
   789 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
   790 
   791 * New functions "sorted" and "sort" in HOL/List.thy.
   792 
   793 * Function "sgn" is now overloaded and available on int, real, complex
   794 (and other numeric types), using class "sgn".  Two possible defs of
   795 sgn are given as equational assumptions in the classes sgn_if and
   796 sgn_div_norm; ordered_idom now also inherits from sgn_if.
   797 INCOMPATIBILITY.
   798 
   799 * New lemma collection field_simps (an extension of ring_simps) for
   800 manipulating (in)equations involving division. Multiplies with all
   801 denominators that can be proved to be non-zero (in equations) or
   802 positive/negative (in inequations).
   803 
   804 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
   805 have been improved and renamed to ring_simps, group_simps and
   806 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
   807 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
   808 
   809 * Library/Commutative_Ring.thy: switched from recdef to function
   810 package; constants add, mul, pow now curried.  Infix syntax for
   811 algebraic operations.
   812 
   813 * Some steps towards more uniform lattice theory development in HOL.
   814 
   815     constants "meet" and "join" now named "inf" and "sup"
   816     constant "Meet" now named "Inf"
   817 
   818     classes "meet_semilorder" and "join_semilorder" now named
   819       "lower_semilattice" and "upper_semilattice"
   820     class "lorder" now named "lattice"
   821     class "comp_lat" now named "complete_lattice"
   822 
   823     Instantiation of lattice classes allows explicit definitions
   824     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
   825 
   826   INCOMPATIBILITY.  Theorem renames:
   827 
   828     meet_left_le            ~> inf_le1
   829     meet_right_le           ~> inf_le2
   830     join_left_le            ~> sup_ge1
   831     join_right_le           ~> sup_ge2
   832     meet_join_le            ~> inf_sup_ord
   833     le_meetI                ~> le_infI
   834     join_leI                ~> le_supI
   835     le_meet                 ~> le_inf_iff
   836     le_join                 ~> ge_sup_conv
   837     meet_idempotent         ~> inf_idem
   838     join_idempotent         ~> sup_idem
   839     meet_comm               ~> inf_commute
   840     join_comm               ~> sup_commute
   841     meet_leI1               ~> le_infI1
   842     meet_leI2               ~> le_infI2
   843     le_joinI1               ~> le_supI1
   844     le_joinI2               ~> le_supI2
   845     meet_assoc              ~> inf_assoc
   846     join_assoc              ~> sup_assoc
   847     meet_left_comm          ~> inf_left_commute
   848     meet_left_idempotent    ~> inf_left_idem
   849     join_left_comm          ~> sup_left_commute
   850     join_left_idempotent    ~> sup_left_idem
   851     meet_aci                ~> inf_aci
   852     join_aci                ~> sup_aci
   853     le_def_meet             ~> le_iff_inf
   854     le_def_join             ~> le_iff_sup
   855     join_absorp2            ~> sup_absorb2
   856     join_absorp1            ~> sup_absorb1
   857     meet_absorp1            ~> inf_absorb1
   858     meet_absorp2            ~> inf_absorb2
   859     meet_join_absorp        ~> inf_sup_absorb
   860     join_meet_absorp        ~> sup_inf_absorb
   861     distrib_join_le         ~> distrib_sup_le
   862     distrib_meet_le         ~> distrib_inf_le
   863 
   864     add_meet_distrib_left   ~> add_inf_distrib_left
   865     add_join_distrib_left   ~> add_sup_distrib_left
   866     is_join_neg_meet        ~> is_join_neg_inf
   867     is_meet_neg_join        ~> is_meet_neg_sup
   868     add_meet_distrib_right  ~> add_inf_distrib_right
   869     add_join_distrib_right  ~> add_sup_distrib_right
   870     add_meet_join_distribs  ~> add_sup_inf_distribs
   871     join_eq_neg_meet        ~> sup_eq_neg_inf
   872     meet_eq_neg_join        ~> inf_eq_neg_sup
   873     add_eq_meet_join        ~> add_eq_inf_sup
   874     meet_0_imp_0            ~> inf_0_imp_0
   875     join_0_imp_0            ~> sup_0_imp_0
   876     meet_0_eq_0             ~> inf_0_eq_0
   877     join_0_eq_0             ~> sup_0_eq_0
   878     neg_meet_eq_join        ~> neg_inf_eq_sup
   879     neg_join_eq_meet        ~> neg_sup_eq_inf
   880     join_eq_if              ~> sup_eq_if
   881 
   882     mono_meet               ~> mono_inf
   883     mono_join               ~> mono_sup
   884     meet_bool_eq            ~> inf_bool_eq
   885     join_bool_eq            ~> sup_bool_eq
   886     meet_fun_eq             ~> inf_fun_eq
   887     join_fun_eq             ~> sup_fun_eq
   888     meet_set_eq             ~> inf_set_eq
   889     join_set_eq             ~> sup_set_eq
   890     meet1_iff               ~> inf1_iff
   891     meet2_iff               ~> inf2_iff
   892     meet1I                  ~> inf1I
   893     meet2I                  ~> inf2I
   894     meet1D1                 ~> inf1D1
   895     meet2D1                 ~> inf2D1
   896     meet1D2                 ~> inf1D2
   897     meet2D2                 ~> inf2D2
   898     meet1E                  ~> inf1E
   899     meet2E                  ~> inf2E
   900     join1_iff               ~> sup1_iff
   901     join2_iff               ~> sup2_iff
   902     join1I1                 ~> sup1I1
   903     join2I1                 ~> sup2I1
   904     join1I1                 ~> sup1I1
   905     join2I2                 ~> sup1I2
   906     join1CI                 ~> sup1CI
   907     join2CI                 ~> sup2CI
   908     join1E                  ~> sup1E
   909     join2E                  ~> sup2E
   910 
   911     is_meet_Meet            ~> is_meet_Inf
   912     Meet_bool_def           ~> Inf_bool_def
   913     Meet_fun_def            ~> Inf_fun_def
   914     Meet_greatest           ~> Inf_greatest
   915     Meet_lower              ~> Inf_lower
   916     Meet_set_def            ~> Inf_set_def
   917 
   918     Sup_def                 ~> Sup_Inf
   919     Sup_bool_eq             ~> Sup_bool_def
   920     Sup_fun_eq              ~> Sup_fun_def
   921     Sup_set_eq              ~> Sup_set_def
   922 
   923     listsp_meetI            ~> listsp_infI
   924     listsp_meet_eq          ~> listsp_inf_eq
   925 
   926     meet_min                ~> inf_min
   927     join_max                ~> sup_max
   928 
   929 * Renamed classes "order" and "linorder": facts "refl", "trans" and
   930 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
   931 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
   932 
   933 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
   934 changed order of proof goals instance proofs.
   935 
   936 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
   937 INCOMPATIBILITY.
   938 
   939 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
   940 INCOMPATIBILITY.
   941 
   942 * Added syntactic class "size"; overloaded constant "size" now has
   943 type "'a::size ==> bool"
   944 
   945 * Renamed constants "Divides.op div", "Divides.op mod" and "Divides.op
   946 dvd" to "Divides.div_class.div", "Divides.div_class.mod" and
   947 "Divides.dvd". INCOMPATIBILITY.
   948 
   949 * Method "lexicographic_order" automatically synthesizes termination
   950 relations as lexicographic combinations of size measures -- 'function'
   951 package.
   952 
   953 * HOL/records: generalised field-update to take a function on the
   954 field rather than the new value: r(|A := x|) is translated to A_update
   955 (K x) r The K-combinator that is internally used is called K_record.
   956 INCOMPATIBILITY: Usage of the plain update functions has to be
   957 adapted.
   958  
   959 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
   960 * x = 0, which are required for a semiring.  Richer structures do not
   961 inherit from semiring_0 anymore, because this property is a theorem
   962 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
   963 there is more to prove, but this is mostly trivial.
   964 
   965 * Class "recpower" is generalized to arbitrary monoids, not just
   966 commutative semirings.  INCOMPATIBILITY: may need to incorporate
   967 commutativity or a semiring properties additionally.
   968 
   969 * Unified locale "partial_order" with class definition (cf. theory
   970 Orderings), added parameter "less".  INCOMPATIBILITY.
   971 
   972 * Constant "List.list_all2" in List.thy now uses authentic syntax.
   973 INCOMPATIBILITY: translations containing list_all2 may go wrong,
   974 better use 'abbreviation'.
   975 
   976 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
   977 
   978 * Renamed constants "0" to "HOL.zero_class.zero" and "1" to
   979 "HOL.one_class.one".  INCOMPATIBILITY.
   980 
   981 * Added class "HOL.eq", allowing for code generation with polymorphic
   982 equality.
   983 
   984 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
   985 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
   986 significant changes for setting up numeral syntax for types:
   987   - New constants Numeral.pred and Numeral.succ instead
   988       of former Numeral.bin_pred and Numeral.bin_succ.
   989   - Use integer operations instead of bin_add, bin_mult and so on.
   990   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
   991   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
   992 
   993 See HOL/Integ/IntArith.thy for an example setup.
   994 
   995 * New top level command 'normal_form' computes the normal form of a
   996 term that may contain free variables.  For example ``normal_form
   997 "rev[a,b,c]"'' produces ``[b,c,a]'' (without proof).  This command is
   998 suitable for heavy-duty computations because the functions are
   999 compiled to ML first.
  1000 
  1001 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  1002 25 like -->); output depends on the "iff" print_mode, the default is
  1003 "A = B" (with priority 50).
  1004 
  1005 * Renamed constants in HOL.thy and Orderings.thy:
  1006     op +   ~> HOL.plus_class.plus
  1007     op -   ~> HOL.minus_class.minus
  1008     uminus ~> HOL.minus_class.uminus
  1009     abs    ~> HOL.abs_class.abs
  1010     op *   ~> HOL.times_class.times
  1011     op <   ~> HOL.ord_class.less
  1012     op <=  ~> HOL.ord_class.less_eq
  1013 
  1014 Adaptions may be required in the following cases:
  1015 
  1016 a) User-defined constants using any of the names "plus", "minus",
  1017 "times", "less" or "less_eq". The standard syntax translations for
  1018 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1019 names.
  1020 
  1021 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1022 INCOMPATIBILITY: use more specific names.
  1023 
  1024 c) Permutative equations (e.g. "a + b = b + a")
  1025 Since the change of names also changes the order of terms, permutative
  1026 rewrite rules may get applied in a different order. Experience shows
  1027 that this is rarely the case (only two adaptions in the whole Isabelle
  1028 distribution).  INCOMPATIBILITY: rewrite proofs
  1029 
  1030 d) ML code directly refering to constant names
  1031 This in general only affects hand-written proof tactics, simprocs and
  1032 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1033 Consider using @{const_name} antiquotation.
  1034 
  1035 * Relations less (<) and less_eq (<=) are also available on type bool.
  1036 Modified syntax to disallow nesting without explicit parentheses,
  1037 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  1038 INCOMPATIBILITY.
  1039 
  1040 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  1041 
  1042 * Relation composition operator "op O" now has precedence 75 and binds
  1043 stronger than union and intersection. INCOMPATIBILITY.
  1044 
  1045 * The old set interval syntax "{m..n(}" (and relatives) has been
  1046 removed.  Use "{m..<n}" (and relatives) instead.
  1047 
  1048 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  1049 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  1050 ``declare [[simproc del: neq]]''.
  1051 
  1052 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  1053 True/False.
  1054 
  1055 * Theorem Cons_eq_map_conv no longer declared as "simp".
  1056 
  1057 * Theorem setsum_mult renamed to setsum_right_distrib.
  1058 
  1059 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  1060 ``rule'' method.
  1061 
  1062 * Reimplemented methods "sat" and "satx", with several improvements:
  1063 goals no longer need to be stated as "<prems> ==> False", equivalences
  1064 (i.e. "=" on type bool) are handled, variable names of the form
  1065 "lit_<n>" are no longer reserved, significant speedup.
  1066 
  1067 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  1068 zChaff is still supported as well.
  1069 
  1070 * 'inductive' and 'datatype': provide projections of mutual rules,
  1071 bundled as foo_bar.inducts;
  1072 
  1073 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  1074 Library.
  1075 
  1076 * Library: moved theory Accessible_Part to main HOL.
  1077 
  1078 * Library: added theory Coinductive_List of potentially infinite lists
  1079 as greatest fixed-point.
  1080 
  1081 * Library: added theory AssocList which implements (finite) maps as
  1082 association lists.
  1083 
  1084 * Method "evaluation" solves goals (i.e. a boolean expression)
  1085 efficiently by compiling it to ML.  The goal is "proved" (via an
  1086 oracle) if it evaluates to True.
  1087 
  1088 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  1089 also when invoked by the simplifier.  This results in the Simplifier
  1090 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  1091 Configuration option fast_arith_split_limit=0 recovers the old
  1092 behavior.
  1093 
  1094 * Support for hex (0x20) and binary (0b1001) numerals.
  1095 
  1096 * New method: reify eqs (t), where eqs are equations for an
  1097 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  1098 parameter, computes a term s::'b and a list xs::'a list and proves the
  1099 theorem I xs s = t. This is also known as reification or quoting. The
  1100 resulting theorem is applied to the subgoal to substitute t with I xs
  1101 s.  If t is omitted, the subgoal itself is reified.
  1102 
  1103 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  1104 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  1105 where f is supposed to be a computable function (in the sense of code
  1106 generattion). The method uses reify to compute s and xs as above then
  1107 applies corr_thm and uses normalization by evaluation to "prove" f s =
  1108 r and finally gets the theorem t = r, which is again applied to the
  1109 subgoal. An Example is available in HOL/ex/ReflectionEx.thy.
  1110 
  1111 * Reflection: Automatic reification now handels binding, an example
  1112 is available in HOL/ex/ReflectionEx.thy
  1113 
  1114 
  1115 *** HOL-Complex ***
  1116 
  1117 * Hyperreal: Functions root and sqrt are now defined on negative real
  1118 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  1119 Nonnegativity side conditions have been removed from many lemmas, so
  1120 that more subgoals may now be solved by simplification; potential
  1121 INCOMPATIBILITY.
  1122 
  1123 * Real: new type classes formalize real normed vector spaces and
  1124 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  1125 and norm :: 'a => real.
  1126 
  1127 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  1128 reals into other types. The overloaded constant Reals :: 'a set is now
  1129 defined as range of_real; potential INCOMPATIBILITY.
  1130 
  1131 * Real: proper support for ML code generation, including 'quickcheck'.
  1132 Reals are implemented as arbitrary precision rationals.
  1133 
  1134 * Hyperreal: Several constants that previously worked only for the
  1135 reals have been generalized, so they now work over arbitrary vector
  1136 spaces. Type annotations may need to be added in some cases; potential
  1137 INCOMPATIBILITY.
  1138 
  1139   Infinitesimal  :: ('a::real_normed_vector) star set
  1140   HFinite        :: ('a::real_normed_vector) star set
  1141   HInfinite      :: ('a::real_normed_vector) star set
  1142   approx         :: ('a::real_normed_vector) star => 'a star => bool
  1143   monad          :: ('a::real_normed_vector) star => 'a star set
  1144   galaxy         :: ('a::real_normed_vector) star => 'a star set
  1145   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  1146   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  1147   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  1148   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  1149   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  1150   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  1151   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  1152   sgn            :: 'a::real_normed_vector => 'a
  1153   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  1154 
  1155 * Complex: Some complex-specific constants are now abbreviations for
  1156 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  1157 hnorm.  Other constants have been entirely removed in favor of the
  1158 polymorphic versions (INCOMPATIBILITY):
  1159 
  1160   approx        <-- capprox
  1161   HFinite       <-- CFinite
  1162   HInfinite     <-- CInfinite
  1163   Infinitesimal <-- CInfinitesimal
  1164   monad         <-- cmonad
  1165   galaxy        <-- cgalaxy
  1166   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  1167   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  1168   (ns)deriv     <-- (ns)cderiv
  1169 
  1170 
  1171 *** HOL-Algebra ***
  1172 
  1173 * Formalisation of ideals and the quotient construction over rings.
  1174 
  1175 * Order and lattice theory no longer based on records.
  1176 INCOMPATIBILITY.
  1177 
  1178 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  1179 greatest_closed.  INCOMPATIBILITY.
  1180 
  1181 * Method algebra is now set up via an attribute.  For examples see
  1182 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  1183 of algebraic structures.
  1184 
  1185 * Renamed theory CRing to Ring.
  1186 
  1187 
  1188 *** HOL-Nominal ***
  1189 
  1190 * Fully featured support for nominal datatypes (binding structures)
  1191 due to the HOL-Nominal logic.  See HOL/Nominal, HOL/Nominal/Examples,
  1192 and http://isabelle.in.tum.de/nominal/download.html
  1193 
  1194 
  1195 *** ML ***
  1196 
  1197 * ML basics: just one true type int, which coincides with IntInf.int
  1198 (even on SML/NJ).
  1199 
  1200 * ML within Isar: antiquotations allow to embed statically-checked
  1201 formal entities in the source, referring to the context available at
  1202 compile-time.  For example:
  1203 
  1204 ML {* @{typ "'a => 'b"} *}
  1205 ML {* @{term "%x. x"} *}
  1206 ML {* @{prop "x == y"} *}
  1207 ML {* @{ctyp "'a => 'b"} *}
  1208 ML {* @{cterm "%x. x"} *}
  1209 ML {* @{cprop "x == y"} *}
  1210 ML {* @{thm asm_rl} *}
  1211 ML {* @{thms asm_rl} *}
  1212 ML {* @{type_name c} *}
  1213 ML {* @{const_name c} *}
  1214 ML {* @{const_syntax c} *}
  1215 ML {* @{context} *}
  1216 ML {* @{theory} *}
  1217 ML {* @{theory Pure} *}
  1218 ML {* @{theory_ref} *}
  1219 ML {* @{theory_ref Pure} *}
  1220 ML {* @{simpset} *}
  1221 ML {* @{claset} *}
  1222 ML {* @{clasimpset} *}
  1223 
  1224 The same works for sources being ``used'' within an Isar context.
  1225 
  1226 * ML in Isar: improved error reporting; extra verbosity with
  1227 ML_Context.trace enabled.
  1228 
  1229 * Pure/General/table.ML: the join operations now works via exceptions
  1230 DUP/SAME instead of type option. This is simpler in simple cases, and
  1231 admits slightly more efficient complex applications.
  1232 
  1233 * Pure: 'advanced' translation functions (parse_translation etc.) now
  1234 use Context.generic instead of just theory.
  1235 
  1236 * Pure: datatype Context.generic joins theory/Proof.context and
  1237 provides some facilities for code that works in either kind of
  1238 context, notably GenericDataFun for uniform theory and proof data.
  1239 
  1240 * Pure: simplified internal attribute type, which is now always
  1241 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  1242 local (Proof.context) attributes have been discontinued, while
  1243 minimizing code duplication. Thm.rule_attribute and
  1244 Thm.declaration_attribute build canonical attributes; see also structure
  1245 Context for further operations on Context.generic, notably
  1246 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  1247 declarations and definitions.
  1248 
  1249 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  1250 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  1251 init only required for impure data. INCOMPATIBILITY: empty really need
  1252 to be empty (no dependencies on theory content!)
  1253 
  1254 * Pure/kernel: consts certification ignores sort constraints given in
  1255 signature declarations. (This information is not relevant to the
  1256 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  1257 potential INCOMPATIBILITY.
  1258 
  1259 * Pure: axiomatic type classes are now purely definitional, with
  1260 explicit proofs of class axioms and super class relations performed
  1261 internally. See Pure/axclass.ML for the main internal interfaces --
  1262 notably AxClass.define_class supercedes AxClass.add_axclass, and
  1263 AxClass.axiomatize_class/classrel/arity supersede
  1264 Sign.add_classes/classrel/arities.
  1265 
  1266 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  1267 global/local versions on theory vs. Proof.context have been
  1268 discontinued; Attrib.syntax and Method.syntax have been adapted
  1269 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  1270 attributes, methods, etc.
  1271 
  1272 * Pure: several functions of signature "... -> theory -> theory * ..."
  1273 have been reoriented to "... -> theory -> ... * theory" in order to
  1274 allow natural usage in combination with the ||>, ||>>, |-> and
  1275 fold_map combinators.
  1276 
  1277 * Pure: official theorem names (closed derivations) and additional
  1278 comments (tags) are now strictly separate.  Name hints -- which are
  1279 maintained as tags -- may be attached any time without affecting the
  1280 derivation.
  1281 
  1282 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  1283 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  1284 achieve the old behaviour.
  1285 
  1286 * Pure: the "Goal" constant is now called "prop", supporting a
  1287 slightly more general idea of ``protecting'' meta-level rule
  1288 statements.
  1289 
  1290 * Pure: Logic.(un)varify only works in a global context, which is now
  1291 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  1292 Logic.legacy_(un)varify as temporary workaround.
  1293 
  1294 * Pure: structure Name provides scalable operations for generating
  1295 internal variable names, notably Name.variants etc.  This replaces
  1296 some popular functions from term.ML:
  1297 
  1298   Term.variant		->  Name.variant
  1299   Term.variantlist	->  Name.variant_list
  1300   Term.invent_names	->  Name.invent_list
  1301 
  1302 Note that low-level renaming rarely occurs in new code -- operations
  1303 from structure Variable are used instead (see below).
  1304 
  1305 * Pure: structure Variable provides fundamental operations for proper
  1306 treatment of fixed/schematic variables in a context.  For example,
  1307 Variable.import introduces fixes for schematics of given facts and
  1308 Variable.export reverses the effect (up to renaming) -- this replaces
  1309 various freeze_thaw operations.
  1310 
  1311 * Pure: structure Goal provides simple interfaces for
  1312 init/conclude/finish and tactical prove operations (replacing former
  1313 Tactic.prove).  Goal.prove is the canonical way to prove results
  1314 within a given context; Goal.prove_global is a degraded version for
  1315 theory level goals, including a global Drule.standard.  Note that
  1316 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  1317 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  1318 in a locale context).
  1319 
  1320 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  1321 and type checking (Syntax.check_term etc.), with common combinations
  1322 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  1323 which are considered legacy and await removal.
  1324 
  1325 * Pure/Syntax: generic interfaces for type unchecking
  1326 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  1327 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  1328 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  1329 available for convenience, but refer to the very same operations using
  1330 a mere theory instead of a full context.
  1331 
  1332 * Isar: simplified treatment of user-level errors, using exception
  1333 ERROR of string uniformly.  Function error now merely raises ERROR,
  1334 without any side effect on output channels.  The Isar toplevel takes
  1335 care of proper display of ERROR exceptions.  ML code may use plain
  1336 handle/can/try; cat_error may be used to concatenate errors like this:
  1337 
  1338   ... handle ERROR msg => cat_error msg "..."
  1339 
  1340 Toplevel ML code (run directly or through the Isar toplevel) may be
  1341 embedded into the Isar toplevel with exception display/debug like
  1342 this:
  1343 
  1344   Isar.toplevel (fn () => ...)
  1345 
  1346 INCOMPATIBILITY, removed special transform_error facilities, removed
  1347 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  1348 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  1349 -- use plain ERROR instead.
  1350 
  1351 * Isar: theory setup now has type (theory -> theory), instead of a
  1352 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  1353 
  1354 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  1355 ProofContext.debug/verbose flags.
  1356 
  1357 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  1358 theory before entering a proof state.  Transactions now always see a
  1359 quasi-functional intermediate checkpoint, both in interactive and
  1360 batch mode.
  1361 
  1362 * Isar: simplified interfaces for outer syntax.  Renamed
  1363 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  1364 OuterSyntax.add_parsers -- this functionality is now included in
  1365 OuterSyntax.command etc.  INCOMPATIBILITY.
  1366 
  1367 * Simplifier: the simpset of a running simplification process now
  1368 contains a proof context (cf. Simplifier.the_context), which is the
  1369 very context that the initial simpset has been retrieved from (by
  1370 simpset_of/local_simpset_of).  Consequently, all plug-in components
  1371 (solver, looper etc.) may depend on arbitrary proof data.
  1372 
  1373 * Simplifier.inherit_context inherits the proof context (plus the
  1374 local bounds) of the current simplification process; any simproc
  1375 etc. that calls the Simplifier recursively should do this!  Removed
  1376 former Simplifier.inherit_bounds, which is already included here --
  1377 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  1378 specify an explicit context using Simplifier.context/theory_context.
  1379 
  1380 * Simplifier/Classical Reasoner: more abstract interfaces
  1381 change_simpset/claset for modifying the simpset/claset reference of a
  1382 theory; raw versions simpset/claset_ref etc. have been discontinued --
  1383 INCOMPATIBILITY.
  1384 
  1385 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  1386 "Trueprop" etc.
  1387 
  1388 
  1389 *** System ***
  1390 
  1391 * settings: ML_IDENTIFIER -- which is appended to user specific heap
  1392 locations -- now includes the Isabelle version identifier as well.
  1393 This simplifies use of multiple Isabelle installations.
  1394 
  1395 * isabelle-process: option -S (secure mode) disables some critical
  1396 operations, notably runtime compilation and evaluation of ML source
  1397 code.
  1398 
  1399 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  1400 
  1401 * Support for parallel execution, using native multicore support of
  1402 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  1403 independent theories, according to the given theory header
  1404 specifications. The maximum number of worker threads is specified via
  1405 usedir option -M or the "max-threads" setting in Proof General. A
  1406 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  1407 to 6 on a 8-core machine.  User-code needs to observe certain
  1408 guidelines for thread-safe programming, see appendix A in the Isar
  1409 Implementation manual.
  1410 
  1411 
  1412 New in Isabelle2005 (October 2005)
  1413 ----------------------------------
  1414 
  1415 *** General ***
  1416 
  1417 * Theory headers: the new header syntax for Isar theories is
  1418 
  1419   theory <name>
  1420   imports <theory1> ... <theoryN>
  1421   uses <file1> ... <fileM>
  1422   begin
  1423 
  1424 where the 'uses' part is optional.  The previous syntax
  1425 
  1426   theory <name> = <theory1> + ... + <theoryN>:
  1427 
  1428 will disappear in the next release.  Use isatool fixheaders to convert
  1429 existing theory files.  Note that there is no change in ancient
  1430 non-Isar theories now, but these will disappear soon.
  1431 
  1432 * Theory loader: parent theories can now also be referred to via
  1433 relative and absolute paths.
  1434 
  1435 * Command 'find_theorems' searches for a list of criteria instead of a
  1436 list of constants. Known criteria are: intro, elim, dest, name:string,
  1437 simp:term, and any term. Criteria can be preceded by '-' to select
  1438 theorems that do not match. Intro, elim, dest select theorems that
  1439 match the current goal, name:s selects theorems whose fully qualified
  1440 name contain s, and simp:term selects all simplification rules whose
  1441 lhs match term.  Any other term is interpreted as pattern and selects
  1442 all theorems matching the pattern. Available in ProofGeneral under
  1443 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  1444 
  1445   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  1446 
  1447 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  1448 matching the current goal as introduction rule and not having "HOL."
  1449 in their name (i.e. not being defined in theory HOL).
  1450 
  1451 * Command 'thms_containing' has been discontinued in favour of
  1452 'find_theorems'; INCOMPATIBILITY.
  1453 
  1454 * Communication with Proof General is now 8bit clean, which means that
  1455 Unicode text in UTF-8 encoding may be used within theory texts (both
  1456 formal and informal parts).  Cf. option -U of the Isabelle Proof
  1457 General interface.  Here are some simple examples (cf. src/HOL/ex):
  1458 
  1459   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  1460   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  1461 
  1462 * Improved efficiency of the Simplifier and, to a lesser degree, the
  1463 Classical Reasoner.  Typical big applications run around 2 times
  1464 faster.
  1465 
  1466 
  1467 *** Document preparation ***
  1468 
  1469 * Commands 'display_drafts' and 'print_drafts' perform simple output
  1470 of raw sources.  Only those symbols that do not require additional
  1471 LaTeX packages (depending on comments in isabellesym.sty) are
  1472 displayed properly, everything else is left verbatim.  isatool display
  1473 and isatool print are used as front ends (these are subject to the
  1474 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  1475 
  1476 * Command tags control specific markup of certain regions of text,
  1477 notably folding and hiding.  Predefined tags include "theory" (for
  1478 theory begin and end), "proof" for proof commands, and "ML" for
  1479 commands involving ML code; the additional tags "visible" and
  1480 "invisible" are unused by default.  Users may give explicit tag
  1481 specifications in the text, e.g. ''by %invisible (auto)''.  The
  1482 interpretation of tags is determined by the LaTeX job during document
  1483 preparation: see option -V of isatool usedir, or options -n and -t of
  1484 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  1485 \isadroptag.
  1486 
  1487 Several document versions may be produced at the same time via isatool
  1488 usedir (the generated index.html will link all of them).  Typical
  1489 specifications include ''-V document=theory,proof,ML'' to present
  1490 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  1491 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  1492 these parts without any formal replacement text.  The Isabelle site
  1493 default settings produce ''document'' and ''outline'' versions as
  1494 specified above.
  1495 
  1496 * Several new antiquotations:
  1497 
  1498   @{term_type term} prints a term with its type annotated;
  1499 
  1500   @{typeof term} prints the type of a term;
  1501 
  1502   @{const const} is the same as @{term const}, but checks that the
  1503   argument is a known logical constant;
  1504 
  1505   @{term_style style term} and @{thm_style style thm} print a term or
  1506   theorem applying a "style" to it
  1507 
  1508   @{ML text}
  1509 
  1510 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  1511 definitions, equations, inequations etc., 'concl' printing only the
  1512 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  1513 to print the specified premise.  TermStyle.add_style provides an ML
  1514 interface for introducing further styles.  See also the "LaTeX Sugar"
  1515 document practical applications.  The ML antiquotation prints
  1516 type-checked ML expressions verbatim.
  1517 
  1518 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  1519 and 'text' support optional locale specification '(in loc)', which
  1520 specifies the default context for interpreting antiquotations.  For
  1521 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  1522 
  1523 * Option 'locale=NAME' of antiquotations specifies an alternative
  1524 context interpreting the subsequent argument.  For example: @{thm
  1525 [locale=lattice] inf_assoc}.
  1526 
  1527 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  1528 a proof context.
  1529 
  1530 * Proper output of antiquotations for theory commands involving a
  1531 proof context (such as 'locale' or 'theorem (in loc) ...').
  1532 
  1533 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  1534 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  1535 
  1536 * isatool usedir: new option -C (default true) controls whether option
  1537 -D should include a copy of the original document directory; -C false
  1538 prevents unwanted effects such as copying of administrative CVS data.
  1539 
  1540 
  1541 *** Pure ***
  1542 
  1543 * Considerably improved version of 'constdefs' command.  Now performs
  1544 automatic type-inference of declared constants; additional support for
  1545 local structure declarations (cf. locales and HOL records), see also
  1546 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  1547 sequential dependencies of definitions within a single 'constdefs'
  1548 section; moreover, the declared name needs to be an identifier.  If
  1549 all fails, consider to fall back on 'consts' and 'defs' separately.
  1550 
  1551 * Improved indexed syntax and implicit structures.  First of all,
  1552 indexed syntax provides a notational device for subscripted
  1553 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  1554 expressions.  Secondly, in a local context with structure
  1555 declarations, number indexes \<^sub>n or the empty index (default
  1556 number 1) refer to a certain fixed variable implicitly; option
  1557 show_structs controls printing of implicit structures.  Typical
  1558 applications of these concepts involve record types and locales.
  1559 
  1560 * New command 'no_syntax' removes grammar declarations (and
  1561 translations) resulting from the given syntax specification, which is
  1562 interpreted in the same manner as for the 'syntax' command.
  1563 
  1564 * 'Advanced' translation functions (parse_translation etc.) may depend
  1565 on the signature of the theory context being presently used for
  1566 parsing/printing, see also isar-ref manual.
  1567 
  1568 * Improved 'oracle' command provides a type-safe interface to turn an
  1569 ML expression of type theory -> T -> term into a primitive rule of
  1570 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  1571 is already included here); see also FOL/ex/IffExample.thy;
  1572 INCOMPATIBILITY.
  1573 
  1574 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  1575 before); "cI" is no longer bound, use "c.intro" instead.
  1576 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  1577 axclasses vs. locales.
  1578 
  1579 * Improved internal renaming of symbolic identifiers -- attach primes
  1580 instead of base 26 numbers.
  1581 
  1582 * New flag show_question_marks controls printing of leading question
  1583 marks in schematic variable names.
  1584 
  1585 * In schematic variable names, *any* symbol following \<^isub> or
  1586 \<^isup> is now treated as part of the base name.  For example, the
  1587 following works without printing of awkward ".0" indexes:
  1588 
  1589   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  1590     by simp
  1591 
  1592 * Inner syntax includes (*(*nested*) comments*).
  1593 
  1594 * Pretty printer now supports unbreakable blocks, specified in mixfix
  1595 annotations as "(00...)".
  1596 
  1597 * Clear separation of logical types and nonterminals, where the latter
  1598 may only occur in 'syntax' specifications or type abbreviations.
  1599 Before that distinction was only partially implemented via type class
  1600 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  1601 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  1602 exotic syntax specifications may require further adaption
  1603 (e.g. Cube/Cube.thy).
  1604 
  1605 * Removed obsolete type class "logic", use the top sort {} instead.
  1606 Note that non-logical types should be declared as 'nonterminals'
  1607 rather than 'types'.  INCOMPATIBILITY for new object-logic
  1608 specifications.
  1609 
  1610 * Attributes 'induct' and 'cases': type or set names may now be
  1611 locally fixed variables as well.
  1612 
  1613 * Simplifier: can now control the depth to which conditional rewriting
  1614 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  1615 Limit.
  1616 
  1617 * Simplifier: simplification procedures may now take the current
  1618 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  1619 interface), which is very useful for calling the Simplifier
  1620 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  1621 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  1622 low-level mk_simproc no longer applies Logic.varify internally, to
  1623 allow for use in a context of fixed variables.
  1624 
  1625 * thin_tac now works even if the assumption being deleted contains !!
  1626 or ==>.  More generally, erule now works even if the major premise of
  1627 the elimination rule contains !! or ==>.
  1628 
  1629 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  1630 
  1631 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  1632 from Pure, which contains all common declarations already.  Both
  1633 theories are defined via plain Isabelle/Isar .thy files.
  1634 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  1635 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  1636 use isatool fixcpure to adapt your theory and ML sources.
  1637 
  1638 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  1639 selections of theorems in named facts via index ranges.
  1640 
  1641 * 'print_theorems': in theory mode, really print the difference
  1642 wrt. the last state (works for interactive theory development only),
  1643 in proof mode print all local facts (cf. 'print_facts');
  1644 
  1645 * 'hide': option '(open)' hides only base names.
  1646 
  1647 * More efficient treatment of intermediate checkpoints in interactive
  1648 theory development.
  1649 
  1650 * Code generator is now invoked via code_module (incremental code
  1651 generation) and code_library (modular code generation, ML structures
  1652 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  1653 must be quoted when used as identifiers.
  1654 
  1655 * New 'value' command for reading, evaluating and printing terms using
  1656 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  1657 quoted when used as identifier.
  1658 
  1659 
  1660 *** Locales ***
  1661 
  1662 * New commands for the interpretation of locale expressions in
  1663 theories (1), locales (2) and proof contexts (3).  These generate
  1664 proof obligations from the expression specification.  After the
  1665 obligations have been discharged, theorems of the expression are added
  1666 to the theory, target locale or proof context.  The synopsis of the
  1667 commands is a follows:
  1668 
  1669   (1) interpretation expr inst
  1670   (2) interpretation target < expr
  1671   (3) interpret expr inst
  1672 
  1673 Interpretation in theories and proof contexts require a parameter
  1674 instantiation of terms from the current context.  This is applied to
  1675 specifications and theorems of the interpreted expression.
  1676 Interpretation in locales only permits parameter renaming through the
  1677 locale expression.  Interpretation is smart in that interpretations
  1678 that are active already do not occur in proof obligations, neither are
  1679 instantiated theorems stored in duplicate.  Use 'print_interps' to
  1680 inspect active interpretations of a particular locale.  For details,
  1681 see the Isar Reference manual.  Examples can be found in
  1682 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  1683 
  1684 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  1685 'interpret' instead.
  1686 
  1687 * New context element 'constrains' for adding type constraints to
  1688 parameters.
  1689 
  1690 * Context expressions: renaming of parameters with syntax
  1691 redeclaration.
  1692 
  1693 * Locale declaration: 'includes' disallowed.
  1694 
  1695 * Proper static binding of attribute syntax -- i.e. types / terms /
  1696 facts mentioned as arguments are always those of the locale definition
  1697 context, independently of the context of later invocations.  Moreover,
  1698 locale operations (renaming and type / term instantiation) are applied
  1699 to attribute arguments as expected.
  1700 
  1701 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  1702 actual attributes; rare situations may require Attrib.attribute to
  1703 embed those attributes into Attrib.src that lack concrete syntax.
  1704 Attribute implementations need to cooperate properly with the static
  1705 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  1706 Attrib.XXX_thm etc. already do the right thing without further
  1707 intervention.  Only unusual applications -- such as "where" or "of"
  1708 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  1709 on the context and the facts involved -- may have to assign parsed
  1710 values to argument tokens explicitly.
  1711 
  1712 * Changed parameter management in theorem generation for long goal
  1713 statements with 'includes'.  INCOMPATIBILITY: produces a different
  1714 theorem statement in rare situations.
  1715 
  1716 * Locale inspection command 'print_locale' omits notes elements.  Use
  1717 'print_locale!' to have them included in the output.
  1718 
  1719 
  1720 *** Provers ***
  1721 
  1722 * Provers/hypsubst.ML: improved version of the subst method, for
  1723 single-step rewriting: it now works in bound variable contexts. New is
  1724 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  1725 rewrite a different subterm than the original subst method, which is
  1726 still available as 'simplesubst'.
  1727 
  1728 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  1729 and quasi orders.
  1730 
  1731 * Provers/trancl.ML: new transitivity reasoner for transitive and
  1732 reflexive-transitive closure of relations.
  1733 
  1734 * Provers/blast.ML: new reference depth_limit to make blast's depth
  1735 limit (previously hard-coded with a value of 20) user-definable.
  1736 
  1737 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  1738 is peformed already.  Object-logics merely need to finish their
  1739 initial simpset configuration as before.  INCOMPATIBILITY.
  1740 
  1741 
  1742 *** HOL ***
  1743 
  1744 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  1745 
  1746   syntax (epsilon)
  1747     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  1748 
  1749 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  1750 and x-symbol; use option '-m epsilon' to get it actually printed.
  1751 Moreover, the mathematically important symbolic identifier \<epsilon>
  1752 becomes available as variable, constant etc.  INCOMPATIBILITY,
  1753 
  1754 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  1755 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  1756 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  1757 support corresponding Isar calculations.
  1758 
  1759 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  1760 instead of ":".
  1761 
  1762 * theory SetInterval: changed the syntax for open intervals:
  1763 
  1764   Old       New
  1765   {..n(}    {..<n}
  1766   {)n..}    {n<..}
  1767   {m..n(}   {m..<n}
  1768   {)m..n}   {m<..n}
  1769   {)m..n(}  {m<..<n}
  1770 
  1771 The old syntax is still supported but will disappear in the next
  1772 release.  For conversion use the following Emacs search and replace
  1773 patterns (these are not perfect but work quite well):
  1774 
  1775   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  1776   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  1777 
  1778 * Theory Commutative_Ring (in Library): method comm_ring for proving
  1779 equalities in commutative rings; method 'algebra' provides a generic
  1780 interface.
  1781 
  1782 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  1783 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  1784 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  1785 be a tuple pattern.
  1786 
  1787 Some new syntax forms are available:
  1788 
  1789   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  1790   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  1791   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  1792   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  1793 
  1794 The latter form "\<Sum>x < k. e" used to be based on a separate
  1795 function "Summation", which has been discontinued.
  1796 
  1797 * theory Finite_Set: in structured induction proofs, the insert case
  1798 is now 'case (insert x F)' instead of the old counterintuitive 'case
  1799 (insert F x)'.
  1800 
  1801 * The 'refute' command has been extended to support a much larger
  1802 fragment of HOL, including axiomatic type classes, constdefs and
  1803 typedefs, inductive datatypes and recursion.
  1804 
  1805 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  1806 Requires zChaff with proof generation to be installed.  See
  1807 HOL/ex/SAT_Examples.thy for examples.
  1808 
  1809 * Datatype induction via method 'induct' now preserves the name of the
  1810 induction variable. For example, when proving P(xs::'a list) by
  1811 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  1812 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  1813 in unstructured proof scripts.
  1814 
  1815 * Reworked implementation of records.  Improved scalability for
  1816 records with many fields, avoiding performance problems for type
  1817 inference. Records are no longer composed of nested field types, but
  1818 of nested extension types. Therefore the record type only grows linear
  1819 in the number of extensions and not in the number of fields.  The
  1820 top-level (users) view on records is preserved.  Potential
  1821 INCOMPATIBILITY only in strange cases, where the theory depends on the
  1822 old record representation. The type generated for a record is called
  1823 <record_name>_ext_type.
  1824 
  1825 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  1826 proofs triggered by a record definition or a simproc (if
  1827 quick_and_dirty is enabled).  Definitions of large records can take
  1828 quite long.
  1829 
  1830 New simproc record_upd_simproc for simplification of multiple record
  1831 updates enabled by default.  Moreover, trivial updates are also
  1832 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  1833 occasionally, since simplification is more powerful by default.
  1834 
  1835 * typedef: proper support for polymorphic sets, which contain extra
  1836 type-variables in the term.
  1837 
  1838 * Simplifier: automatically reasons about transitivity chains
  1839 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  1840 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  1841 old proofs break occasionally as simplification may now solve more
  1842 goals than previously.
  1843 
  1844 * Simplifier: converts x <= y into x = y if assumption y <= x is
  1845 present.  Works for all partial orders (class "order"), in particular
  1846 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  1847 just like y <= x.
  1848 
  1849 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  1850 bound variable or a constant then the let is unfolded.  Otherwise
  1851 first a is simplified to b, and then f b is simplified to g. If
  1852 possible we abstract b from g arriving at "let x = b in h x",
  1853 otherwise we unfold the let and arrive at g.  The simproc can be
  1854 enabled/disabled by the reference use_let_simproc.  Potential
  1855 INCOMPATIBILITY since simplification is more powerful by default.
  1856 
  1857 * Classical reasoning: the meson method now accepts theorems as arguments.
  1858 
  1859 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  1860 jobs to provide advice on the provability of subgoals.
  1861 
  1862 * Theory OrderedGroup and Ring_and_Field: various additions and
  1863 improvements to faciliate calculations involving equalities and
  1864 inequalities.
  1865 
  1866 The following theorems have been eliminated or modified
  1867 (INCOMPATIBILITY):
  1868 
  1869   abs_eq             now named abs_of_nonneg
  1870   abs_of_ge_0        now named abs_of_nonneg
  1871   abs_minus_eq       now named abs_of_nonpos
  1872   imp_abs_id         now named abs_of_nonneg
  1873   imp_abs_neg_id     now named abs_of_nonpos
  1874   mult_pos           now named mult_pos_pos
  1875   mult_pos_le        now named mult_nonneg_nonneg
  1876   mult_pos_neg_le    now named mult_nonneg_nonpos
  1877   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  1878   mult_neg           now named mult_neg_neg
  1879   mult_neg_le        now named mult_nonpos_nonpos
  1880 
  1881 * The following lemmas in Ring_and_Field have been added to the simplifier:
  1882      
  1883      zero_le_square
  1884      not_square_less_zero 
  1885 
  1886   The following lemmas have been deleted from Real/RealPow:
  1887   
  1888      realpow_zero_zero
  1889      realpow_two
  1890      realpow_less
  1891      zero_le_power
  1892      realpow_two_le
  1893      abs_realpow_two
  1894      realpow_two_abs     
  1895 
  1896 * Theory Parity: added rules for simplifying exponents.
  1897 
  1898 * Theory List:
  1899 
  1900 The following theorems have been eliminated or modified
  1901 (INCOMPATIBILITY):
  1902 
  1903   list_all_Nil       now named list_all.simps(1)
  1904   list_all_Cons      now named list_all.simps(2)
  1905   list_all_conv      now named list_all_iff
  1906   set_mem_eq         now named mem_iff
  1907 
  1908 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  1909 asymptotic "big O" calculations.  See the notes in BigO.thy.
  1910 
  1911 
  1912 *** HOL-Complex ***
  1913 
  1914 * Theory RealDef: better support for embedding natural numbers and
  1915 integers in the reals.
  1916 
  1917 The following theorems have been eliminated or modified
  1918 (INCOMPATIBILITY):
  1919 
  1920   exp_ge_add_one_self  now requires no hypotheses
  1921   real_of_int_add      reversed direction of equality (use [symmetric])
  1922   real_of_int_minus    reversed direction of equality (use [symmetric])
  1923   real_of_int_diff     reversed direction of equality (use [symmetric])
  1924   real_of_int_mult     reversed direction of equality (use [symmetric])
  1925 
  1926 * Theory RComplete: expanded support for floor and ceiling functions.
  1927 
  1928 * Theory Ln is new, with properties of the natural logarithm
  1929 
  1930 * Hyperreal: There is a new type constructor "star" for making
  1931 nonstandard types.  The old type names are now type synonyms:
  1932 
  1933   hypreal = real star
  1934   hypnat = nat star
  1935   hcomplex = complex star
  1936 
  1937 * Hyperreal: Many groups of similarly-defined constants have been
  1938 replaced by polymorphic versions (INCOMPATIBILITY):
  1939 
  1940   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  1941 
  1942   starset      <-- starsetNat, starsetC
  1943   *s*          <-- *sNat*, *sc*
  1944   starset_n    <-- starsetNat_n, starsetC_n
  1945   *sn*         <-- *sNatn*, *scn*
  1946   InternalSets <-- InternalNatSets, InternalCSets
  1947 
  1948   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  1949   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  1950   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  1951   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  1952   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  1953 
  1954 * Hyperreal: Many type-specific theorems have been removed in favor of
  1955 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  1956 
  1957   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  1958   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  1959   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  1960   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  1961   right_minus <-- hypreal_add_minus
  1962   left_minus <-- {hypreal,hcomplex}_add_minus_left
  1963   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  1964   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  1965   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  1966   mult_1_right <-- hcomplex_mult_one_right
  1967   mult_zero_left <-- hcomplex_mult_zero_left
  1968   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  1969   right_distrib <-- hypnat_add_mult_distrib2
  1970   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  1971   right_inverse <-- hypreal_mult_inverse
  1972   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  1973   order_refl <-- {hypreal,hypnat}_le_refl
  1974   order_trans <-- {hypreal,hypnat}_le_trans
  1975   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  1976   order_less_le <-- {hypreal,hypnat}_less_le
  1977   linorder_linear <-- {hypreal,hypnat}_le_linear
  1978   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  1979   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  1980   add_nonneg_nonneg <-- hypreal_le_add_order
  1981 
  1982 * Hyperreal: Separate theorems having to do with type-specific
  1983 versions of constants have been merged into theorems that apply to the
  1984 new polymorphic constants (INCOMPATIBILITY):
  1985 
  1986   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  1987   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  1988   STAR_Un <-- {STAR,NatStar,STARC}_Un
  1989   STAR_Int <-- {STAR,NatStar,STARC}_Int
  1990   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  1991   STAR_subset <-- {STAR,NatStar,STARC}_subset
  1992   STAR_mem <-- {STAR,NatStar,STARC}_mem
  1993   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  1994   STAR_diff <-- {STAR,STARC}_diff
  1995   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  1996     STARC_hcomplex_of_complex}_image_subset
  1997   starset_n_Un <-- starset{Nat,C}_n_Un
  1998   starset_n_Int <-- starset{Nat,C}_n_Int
  1999   starset_n_Compl <-- starset{Nat,C}_n_Compl
  2000   starset_n_diff <-- starset{Nat,C}_n_diff
  2001   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  2002   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  2003   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  2004   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  2005   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  2006   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  2007   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  2008   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  2009   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  2010   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  2011   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  2012   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  2013   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  2014   starfun_diff <-- starfun{C,RC,CR}_diff
  2015   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  2016   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  2017   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  2018   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  2019   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  2020   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  2021   starfun_Id <-- starfunC_Id
  2022   starfun_approx <-- starfun{Nat,CR}_approx
  2023   starfun_capprox <-- starfun{C,RC}_capprox
  2024   starfun_abs <-- starfunNat_rabs
  2025   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  2026   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  2027   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  2028   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  2029   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  2030   starfun_add_approx <-- starfunCR_add_approx
  2031   starfun_inverse_inverse <-- starfunC_inverse_inverse
  2032   starfun_divide <-- starfun{C,CR,RC}_divide
  2033   starfun_n <-- starfun{Nat,C}_n
  2034   starfun_n_mult <-- starfun{Nat,C}_n_mult
  2035   starfun_n_add <-- starfun{Nat,C}_n_add
  2036   starfun_n_add_minus <-- starfunNat_n_add_minus
  2037   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  2038   starfun_n_minus <-- starfun{Nat,C}_n_minus
  2039   starfun_n_eq <-- starfun{Nat,C}_n_eq
  2040 
  2041   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  2042   star_n_minus <-- {hypreal,hcomplex}_minus
  2043   star_n_diff <-- {hypreal,hcomplex}_diff
  2044   star_n_mult <-- {hypreal,hcomplex}_mult
  2045   star_n_inverse <-- {hypreal,hcomplex}_inverse
  2046   star_n_le <-- {hypreal,hypnat}_le
  2047   star_n_less <-- {hypreal,hypnat}_less
  2048   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  2049   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  2050   star_n_abs <-- hypreal_hrabs
  2051   star_n_divide <-- hcomplex_divide
  2052 
  2053   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  2054   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  2055   star_of_diff <-- hypreal_of_real_diff
  2056   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  2057   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  2058   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  2059   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  2060   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  2061   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  2062   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  2063   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  2064   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  2065   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  2066   star_of_number_of <-- {hypreal,hcomplex}_number_of
  2067   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  2068   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  2069   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  2070   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  2071   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  2072   star_of_power <-- hypreal_of_real_power
  2073   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  2074 
  2075 * Hyperreal: new method "transfer" that implements the transfer
  2076 principle of nonstandard analysis. With a subgoal that mentions
  2077 nonstandard types like "'a star", the command "apply transfer"
  2078 replaces it with an equivalent one that mentions only standard types.
  2079 To be successful, all free variables must have standard types; non-
  2080 standard variables must have explicit universal quantifiers.
  2081 
  2082 * Hyperreal: A theory of Taylor series.
  2083 
  2084 
  2085 *** HOLCF ***
  2086 
  2087 * Discontinued special version of 'constdefs' (which used to support
  2088 continuous functions) in favor of the general Pure one with full
  2089 type-inference.
  2090 
  2091 * New simplification procedure for solving continuity conditions; it
  2092 is much faster on terms with many nested lambda abstractions (cubic
  2093 instead of exponential time).
  2094 
  2095 * New syntax for domain package: selector names are now optional.
  2096 Parentheses should be omitted unless argument is lazy, for example:
  2097 
  2098   domain 'a stream = cons "'a" (lazy "'a stream")
  2099 
  2100 * New command 'fixrec' for defining recursive functions with pattern
  2101 matching; defining multiple functions with mutual recursion is also
  2102 supported.  Patterns may include the constants cpair, spair, up, sinl,
  2103 sinr, or any data constructor defined by the domain package. The given
  2104 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  2105 syntax and examples.
  2106 
  2107 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  2108 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  2109 but the proof obligation additionally includes an admissibility
  2110 requirement. The packages generate instances of class cpo or pcpo,
  2111 with continuity and strictness theorems for Rep and Abs.
  2112 
  2113 * HOLCF: Many theorems have been renamed according to a more standard naming
  2114 scheme (INCOMPATIBILITY):
  2115 
  2116   foo_inject:  "foo$x = foo$y ==> x = y"
  2117   foo_eq:      "(foo$x = foo$y) = (x = y)"
  2118   foo_less:    "(foo$x << foo$y) = (x << y)"
  2119   foo_strict:  "foo$UU = UU"
  2120   foo_defined: "... ==> foo$x ~= UU"
  2121   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  2122 
  2123 
  2124 *** ZF ***
  2125 
  2126 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  2127 including the First Isomorphism Theorem (on quotienting by the kernel
  2128 of a homomorphism).
  2129 
  2130 * ZF/Simplifier: install second copy of type solver that actually
  2131 makes use of TC rules declared to Isar proof contexts (or locales);
  2132 the old version is still required for ML proof scripts.
  2133 
  2134 
  2135 *** Cube ***
  2136 
  2137 * Converted to Isar theory format; use locales instead of axiomatic
  2138 theories.
  2139 
  2140 
  2141 *** ML ***
  2142 
  2143 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  2144 for ||>, ||>>, |>>,
  2145 
  2146 * Pure/library.ML no longer defines its own option datatype, but uses
  2147 that of the SML basis, which has constructors NONE and SOME instead of
  2148 None and Some, as well as exception Option.Option instead of OPTION.
  2149 The functions the, if_none, is_some, is_none have been adapted
  2150 accordingly, while Option.map replaces apsome.
  2151 
  2152 * Pure/library.ML: the exception LIST has been given up in favour of
  2153 the standard exceptions Empty and Subscript, as well as
  2154 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  2155 superceded by the standard hd and tl functions etc.
  2156 
  2157 A number of basic list functions are no longer exported to the ML
  2158 toplevel, as they are variants of predefined functions.  The following
  2159 suggests how one can translate existing code:
  2160 
  2161     rev_append xs ys = List.revAppend (xs, ys)
  2162     nth_elem (i, xs) = List.nth (xs, i)
  2163     last_elem xs = List.last xs
  2164     flat xss = List.concat xss
  2165     seq fs = List.app fs
  2166     partition P xs = List.partition P xs
  2167     mapfilter f xs = List.mapPartial f xs
  2168 
  2169 * Pure/library.ML: several combinators for linear functional
  2170 transformations, notably reverse application and composition:
  2171 
  2172   x |> f                f #> g
  2173   (x, y) |-> f          f #-> g
  2174 
  2175 * Pure/library.ML: introduced/changed precedence of infix operators:
  2176 
  2177   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  2178   infix 2 ?;
  2179   infix 3 o oo ooo oooo;
  2180   infix 4 ~~ upto downto;
  2181 
  2182 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  2183 infix operators.
  2184 
  2185 * Pure/library.ML: natural list combinators fold, fold_rev, and
  2186 fold_map support linear functional transformations and nesting.  For
  2187 example:
  2188 
  2189   fold f [x1, ..., xN] y =
  2190     y |> f x1 |> ... |> f xN
  2191 
  2192   (fold o fold) f [xs1, ..., xsN] y =
  2193     y |> fold f xs1 |> ... |> fold f xsN
  2194 
  2195   fold f [x1, ..., xN] =
  2196     f x1 #> ... #> f xN
  2197 
  2198   (fold o fold) f [xs1, ..., xsN] =
  2199     fold f xs1 #> ... #> fold f xsN
  2200 
  2201 * Pure/library.ML: the following selectors on type 'a option are
  2202 available:
  2203 
  2204   the:               'a option -> 'a  (*partial*)
  2205   these:             'a option -> 'a  where 'a = 'b list
  2206   the_default: 'a -> 'a option -> 'a
  2207   the_list:          'a option -> 'a list
  2208 
  2209 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2210 basic operations for association lists, following natural argument
  2211 order; moreover the explicit equality predicate passed here avoids
  2212 potentially expensive polymorphic runtime equality checks.
  2213 The old functions may be expressed as follows:
  2214 
  2215   assoc = uncurry (AList.lookup (op =))
  2216   assocs = these oo AList.lookup (op =)
  2217   overwrite = uncurry (AList.update (op =)) o swap
  2218 
  2219 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2220 
  2221   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  2222   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  2223 
  2224 replacing make_keylist and keyfilter (occassionally used)
  2225 Naive rewrites:
  2226 
  2227   make_keylist = AList.make
  2228   keyfilter = AList.find (op =)
  2229 
  2230 * eq_fst and eq_snd now take explicit equality parameter, thus
  2231   avoiding eqtypes. Naive rewrites:
  2232 
  2233     eq_fst = eq_fst (op =)
  2234     eq_snd = eq_snd (op =)
  2235 
  2236 * Removed deprecated apl and apr (rarely used).
  2237   Naive rewrites:
  2238 
  2239     apl (n, op) =>>= curry op n
  2240     apr (op, m) =>>= fn n => op (n, m)
  2241 
  2242 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  2243 provides a reasonably efficient light-weight implementation of sets as
  2244 lists.
  2245 
  2246 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  2247 few new operations; existing lookup and update are now curried to
  2248 follow natural argument order (for use with fold etc.);
  2249 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  2250 
  2251 * Pure/General: output via the Isabelle channels of
  2252 writeln/warning/error etc. is now passed through Output.output, with a
  2253 hook for arbitrary transformations depending on the print_mode
  2254 (cf. Output.add_mode -- the first active mode that provides a output
  2255 function wins).  Already formatted output may be embedded into further
  2256 text via Output.raw; the result of Pretty.string_of/str_of and derived
  2257 functions (string_of_term/cterm/thm etc.) is already marked raw to
  2258 accommodate easy composition of diagnostic messages etc.  Programmers
  2259 rarely need to care about Output.output or Output.raw at all, with
  2260 some notable exceptions: Output.output is required when bypassing the
  2261 standard channels (writeln etc.), or in token translations to produce
  2262 properly formatted results; Output.raw is required when capturing
  2263 already output material that will eventually be presented to the user
  2264 a second time.  For the default print mode, both Output.output and
  2265 Output.raw have no effect.
  2266 
  2267 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  2268 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  2269 cumulative results are displayed at the end of a batch session.
  2270 
  2271 * Pure/General: File.sysify_path and File.quote_sysify path have been
  2272 replaced by File.platform_path and File.shell_path (with appropriate
  2273 hooks).  This provides a clean interface for unusual systems where the
  2274 internal and external process view of file names are different.
  2275 
  2276 * Pure: more efficient orders for basic syntactic entities: added
  2277 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  2278 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  2279 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  2280 orders now -- potential INCOMPATIBILITY for code that depends on a
  2281 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  2282 Library.sort_strings on result).
  2283 
  2284 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  2285 fold_types traverse types/terms from left to right, observing natural
  2286 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  2287 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  2288 
  2289 * Pure: name spaces have been refined, with significant changes of the
  2290 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  2291 to extern(_table).  The plain name entry path is superceded by a
  2292 general 'naming' context, which also includes the 'policy' to produce
  2293 a fully qualified name and external accesses of a fully qualified
  2294 name; NameSpace.extend is superceded by context dependent
  2295 Sign.declare_name.  Several theory and proof context operations modify
  2296 the naming context.  Especially note Theory.restore_naming and
  2297 ProofContext.restore_naming to get back to a sane state; note that
  2298 Theory.add_path is no longer sufficient to recover from
  2299 Theory.absolute_path in particular.
  2300 
  2301 * Pure: new flags short_names (default false) and unique_names
  2302 (default true) for controlling output of qualified names.  If
  2303 short_names is set, names are printed unqualified.  If unique_names is
  2304 reset, the name prefix is reduced to the minimum required to achieve
  2305 the original result when interning again, even if there is an overlap
  2306 with earlier declarations.
  2307 
  2308 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  2309 now 'extend', and 'merge' gets an additional Pretty.pp argument
  2310 (useful for printing error messages).  INCOMPATIBILITY.
  2311 
  2312 * Pure: major reorganization of the theory context.  Type Sign.sg and
  2313 Theory.theory are now identified, referring to the universal
  2314 Context.theory (see Pure/context.ML).  Actual signature and theory
  2315 content is managed as theory data.  The old code and interfaces were
  2316 spread over many files and structures; the new arrangement introduces
  2317 considerable INCOMPATIBILITY to gain more clarity:
  2318 
  2319   Context -- theory management operations (name, identity, inclusion,
  2320     parents, ancestors, merge, etc.), plus generic theory data;
  2321 
  2322   Sign -- logical signature and syntax operations (declaring consts,
  2323     types, etc.), plus certify/read for common entities;
  2324 
  2325   Theory -- logical theory operations (stating axioms, definitions,
  2326     oracles), plus a copy of logical signature operations (consts,
  2327     types, etc.); also a few basic management operations (Theory.copy,
  2328     Theory.merge, etc.)
  2329 
  2330 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  2331 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  2332 for convenience -- they merely return the theory.
  2333 
  2334 * Pure: type Type.tsig is superceded by theory in most interfaces.
  2335 
  2336 * Pure: the Isar proof context type is already defined early in Pure
  2337 as Context.proof (note that ProofContext.context and Proof.context are
  2338 aliases, where the latter is the preferred name).  This enables other
  2339 Isabelle components to refer to that type even before Isar is present.
  2340 
  2341 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  2342 typeK, constK, axiomK, oracleK), but provide explicit operations for
  2343 any of these kinds.  For example, Sign.intern typeK is now
  2344 Sign.intern_type, Theory.hide_space Sign.typeK is now
  2345 Theory.hide_types.  Also note that former
  2346 Theory.hide_classes/types/consts are now
  2347 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  2348 internalize their arguments!  INCOMPATIBILITY.
  2349 
  2350 * Pure: get_thm interface (of PureThy and ProofContext) expects
  2351 datatype thmref (with constructors Name and NameSelection) instead of
  2352 plain string -- INCOMPATIBILITY;
  2353 
  2354 * Pure: cases produced by proof methods specify options, where NONE
  2355 means to remove case bindings -- INCOMPATIBILITY in
  2356 (RAW_)METHOD_CASES.
  2357 
  2358 * Pure: the following operations retrieve axioms or theorems from a
  2359 theory node or theory hierarchy, respectively:
  2360 
  2361   Theory.axioms_of: theory -> (string * term) list
  2362   Theory.all_axioms_of: theory -> (string * term) list
  2363   PureThy.thms_of: theory -> (string * thm) list
  2364   PureThy.all_thms_of: theory -> (string * thm) list
  2365 
  2366 * Pure: print_tac now outputs the goal through the trace channel.
  2367 
  2368 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  2369 Reference Toplevel.debug (default false) controls detailed printing
  2370 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  2371 controls execution profiling -- set to 1 for time and 2 for space
  2372 (both increase the runtime).
  2373 
  2374 * Isar session: The initial use of ROOT.ML is now always timed,
  2375 i.e. the log will show the actual process times, in contrast to the
  2376 elapsed wall-clock time that the outer shell wrapper produces.
  2377 
  2378 * Simplifier: improved handling of bound variables (nameless
  2379 representation, avoid allocating new strings).  Simprocs that invoke
  2380 the Simplifier recursively should use Simplifier.inherit_bounds to
  2381 avoid local name clashes.  Failure to do so produces warnings
  2382 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  2383 for further details.
  2384 
  2385 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  2386 bindings for all theorems stored within a given theory; this may help
  2387 in porting non-Isar theories to Isar ones, while keeping ML proof
  2388 scripts for the time being.
  2389 
  2390 * ML operator HTML.with_charset specifies the charset begin used for
  2391 generated HTML files.  For example:
  2392 
  2393   HTML.with_charset "utf-8" use_thy "Hebrew";
  2394   HTML.with_charset "utf-8" use_thy "Chinese";
  2395 
  2396 
  2397 *** System ***
  2398 
  2399 * Allow symlinks to all proper Isabelle executables (Isabelle,
  2400 isabelle, isatool etc.).
  2401 
  2402 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  2403 isatool doc, isatool mkdir, display_drafts etc.).
  2404 
  2405 * isatool usedir: option -f allows specification of the ML file to be
  2406 used by Isabelle; default is ROOT.ML.
  2407 
  2408 * New isatool version outputs the version identifier of the Isabelle
  2409 distribution being used.
  2410 
  2411 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  2412 (containing Boolean satisfiability problems) into Isabelle/HOL
  2413 theories.
  2414 
  2415 
  2416 
  2417 New in Isabelle2004 (April 2004)
  2418 --------------------------------
  2419 
  2420 *** General ***
  2421 
  2422 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  2423   Replaces linorder.ML.
  2424 
  2425 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  2426   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  2427   (\<a>...\<z>), are now considered normal letters, and can therefore
  2428   be used anywhere where an ASCII letter (a...zA...Z) has until
  2429   now. COMPATIBILITY: This obviously changes the parsing of some
  2430   terms, especially where a symbol has been used as a binder, say
  2431   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  2432   as an identifier.  Fix it by inserting a space around former
  2433   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  2434   existing theory and ML files.
  2435 
  2436 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  2437 
  2438 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  2439   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  2440   a normal (but invisible) letter. For multiple letter subscripts repeat
  2441   \<^isub> like this: x\<^isub>1\<^isub>2.
  2442 
  2443 * Pure: There are now sub-/superscripts that can span more than one
  2444   character. Text between \<^bsub> and \<^esub> is set in subscript in
  2445   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  2446   superscript. The new control characters are not identifier parts.
  2447 
  2448 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  2449   content of "..." to the latex file instead of \isacntrl... . The "..."
  2450   may consist of any printable characters excluding the end bracket >.
  2451 
  2452 * Pure: Using new Isar command "finalconsts" (or the ML functions
  2453   Theory.add_finals or Theory.add_finals_i) it is now possible to
  2454   declare constants "final", which prevents their being given a definition
  2455   later.  It is useful for constants whose behaviour is fixed axiomatically
  2456   rather than definitionally, such as the meta-logic connectives.
  2457 
  2458 * Pure: 'instance' now handles general arities with general sorts
  2459   (i.e. intersections of classes),
  2460 
  2461 * Presentation: generated HTML now uses a CSS style sheet to make layout
  2462   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  2463   It can be changed to alter the colors/layout of generated pages.
  2464 
  2465 
  2466 *** Isar ***
  2467 
  2468 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  2469   cut_tac, subgoal_tac and thin_tac:
  2470   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  2471     locales are no longer forced to write Isar proof scripts.
  2472     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  2473     emulations.
  2474   - INCOMPATIBILITY: names of variables to be instantiated may no
  2475     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  2476     This is consistent with the instantiation attribute "where".
  2477 
  2478 * Attributes "where" and "of":
  2479   - Now take type variables of instantiated theorem into account when reading
  2480     the instantiation string.  This fixes a bug that caused instantiated
  2481     theorems to have too special types in some circumstances.
  2482   - "where" permits explicit instantiations of type variables.
  2483 
  2484 * Calculation commands "moreover" and "also" no longer interfere with
  2485   current facts ("this"), admitting arbitrary combinations with "then"
  2486   and derived forms.
  2487 
  2488 * Locales:
  2489   - Goal statements involving the context element "includes" no longer
  2490     generate theorems with internal delta predicates (those ending on
  2491     "_axioms") in the premise.
  2492     Resolve particular premise with <locale>.intro to obtain old form.
  2493   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  2494     specification and "includes" elements in goal statement.
  2495   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  2496     [intro?] and [elim?] (respectively) by default.
  2497   - Experimental command for instantiation of locales in proof contexts:
  2498         instantiate <label>[<attrs>]: <loc>
  2499     Instantiates locale <loc> and adds all its theorems to the current context
  2500     taking into account their attributes.  Label and attrs are optional
  2501     modifiers, like in theorem declarations.  If present, names of
  2502     instantiated theorems are qualified with <label>, and the attributes
  2503     <attrs> are applied after any attributes these theorems might have already.
  2504       If the locale has assumptions, a chained fact of the form
  2505     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  2506     are derived.  The command does not support old-style locales declared
  2507     with "locale (open)".
  2508       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  2509 
  2510 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  2511   (Isar) contexts.
  2512 
  2513 
  2514 *** HOL ***
  2515 
  2516 * Proof import: new image HOL4 contains the imported library from
  2517   the HOL4 system with about 2500 theorems. It is imported by
  2518   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  2519   can be used like any other Isabelle image.  See
  2520   HOL/Import/HOL/README for more information.
  2521 
  2522 * Simplifier:
  2523   - Much improved handling of linear and partial orders.
  2524     Reasoners for linear and partial orders are set up for type classes
  2525     "linorder" and "order" respectively, and are added to the default simpset
  2526     as solvers.  This means that the simplifier can build transitivity chains
  2527     to solve goals from the assumptions.
  2528   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  2529     of blast or auto after simplification become unnecessary because the goal
  2530     is solved by simplification already.
  2531 
  2532 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  2533     all proved in axiomatic type classes for semirings, rings and fields.
  2534 
  2535 * Numerics:
  2536   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  2537     now formalized using the Ring_and_Field theory mentioned above.
  2538   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  2539     than before, because now they are set up once in a generic manner.
  2540   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  2541     Look for the general versions in Ring_and_Field (and Power if they concern
  2542     exponentiation).
  2543 
  2544 * Type "rat" of the rational numbers is now available in HOL-Complex.
  2545 
  2546 * Records:
  2547   - Record types are now by default printed with their type abbreviation
  2548     instead of the list of all field types. This can be configured via
  2549     the reference "print_record_type_abbr".
  2550   - Simproc "record_upd_simproc" for simplification of multiple updates added
  2551     (not enabled by default).
  2552   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  2553     EX x. x = sel r to True (not enabled by default).
  2554   - Tactic "record_split_simp_tac" to split and simplify records added.
  2555 
  2556 * 'specification' command added, allowing for definition by
  2557   specification.  There is also an 'ax_specification' command that
  2558   introduces the new constants axiomatically.
  2559 
  2560 * arith(_tac) is now able to generate counterexamples for reals as well.
  2561 
  2562 * HOL-Algebra: new locale "ring" for non-commutative rings.
  2563 
  2564 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  2565   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  2566 
  2567 * HOL-Matrix: a first theory for matrices in HOL with an application of
  2568   matrix theory to linear programming.
  2569 
  2570 * Unions and Intersections:
  2571   The latex output syntax of UN and INT has been changed
  2572   from "\Union x \in A. B" to "\Union_{x \in A} B"
  2573   i.e. the index formulae has become a subscript.
  2574   Similarly for "\Union x. B", and for \Inter instead of \Union.
  2575 
  2576 * Unions and Intersections over Intervals:
  2577   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  2578   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  2579   like in normal math, and corresponding versions for < and for intersection.
  2580 
  2581 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  2582   lexicographic dictonary ordering has been added as "lexord".
  2583 
  2584 * ML: the legacy theory structures Int and List have been removed. They had
  2585   conflicted with ML Basis Library structures having the same names.
  2586 
  2587 * 'refute' command added to search for (finite) countermodels.  Only works
  2588   for a fragment of HOL.  The installation of an external SAT solver is
  2589   highly recommended.  See "HOL/Refute.thy" for details.
  2590 
  2591 * 'quickcheck' command: Allows to find counterexamples by evaluating
  2592   formulae under an assignment of free variables to random values.
  2593   In contrast to 'refute', it can deal with inductive datatypes,
  2594   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  2595   for examples.
  2596 
  2597 
  2598 *** HOLCF ***
  2599 
  2600 * Streams now come with concatenation and are part of the HOLCF image
  2601 
  2602 
  2603 
  2604 New in Isabelle2003 (May 2003)
  2605 ------------------------------
  2606 
  2607 *** General ***
  2608 
  2609 * Provers/simplifier:
  2610 
  2611   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  2612     Assumptions are now subject to complete mutual simplification,
  2613     not just from left to right. The simplifier now preserves
  2614     the order of assumptions.
  2615 
  2616     Potential INCOMPATIBILITY:
  2617 
  2618     -- simp sometimes diverges where the old version did
  2619        not, e.g. invoking simp on the goal
  2620 
  2621         [| P (f x); y = x; f x = f y |] ==> Q
  2622 
  2623        now gives rise to the infinite reduction sequence
  2624 
  2625         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  2626 
  2627        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  2628        kind of problem.
  2629 
  2630     -- Tactics combining classical reasoner and simplification (such as auto)
  2631        are also affected by this change, because many of them rely on
  2632        simp. They may sometimes diverge as well or yield a different numbers
  2633        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  2634        in case of problems. Sometimes subsequent calls to the classical
  2635        reasoner will fail because a preceeding call to the simplifier too
  2636        eagerly simplified the goal, e.g. deleted redundant premises.
  2637 
  2638   - The simplifier trace now shows the names of the applied rewrite rules
  2639 
  2640   - You can limit the number of recursive invocations of the simplifier
  2641     during conditional rewriting (where the simplifie tries to solve the
  2642     conditions before applying the rewrite rule):
  2643     ML "simp_depth_limit := n"
  2644     where n is an integer. Thus you can force termination where previously
  2645     the simplifier would diverge.
  2646 
  2647   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  2648 
  2649   - No longer aborts on failed congruence proof.  Instead, the
  2650     congruence is ignored.
  2651 
  2652 * Pure: New generic framework for extracting programs from constructive
  2653   proofs. See HOL/Extraction.thy for an example instantiation, as well
  2654   as HOL/Extraction for some case studies.
  2655 
  2656 * Pure: The main goal of the proof state is no longer shown by default, only
  2657 the subgoals. This behaviour is controlled by a new flag.
  2658    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  2659 (ML: Proof.show_main_goal).
  2660 
  2661 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  2662 rules whose conclusion matches subgoal 1:
  2663       PG menu: Isabelle/Isar -> Show me -> matching rules
  2664 The rules are ordered by how closely they match the subgoal.
  2665 In particular, rules that solve a subgoal outright are displayed first
  2666 (or rather last, the way they are printed).
  2667 (ML: ProofGeneral.print_intros())
  2668 
  2669 * Pure: New flag trace_unify_fail causes unification to print
  2670 diagnostic information (PG: in trace buffer) when it fails. This is
  2671 useful for figuring out why single step proofs like rule, erule or
  2672 assumption failed.
  2673 
  2674 * Pure: Locale specifications now produce predicate definitions
  2675 according to the body of text (covering assumptions modulo local
  2676 definitions); predicate "loc_axioms" covers newly introduced text,
  2677 while "loc" is cumulative wrt. all included locale expressions; the
  2678 latter view is presented only on export into the global theory
  2679 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  2680 on the old view without predicates;
  2681 
  2682 * Pure: predefined locales "var" and "struct" are useful for sharing
  2683 parameters (as in CASL, for example); just specify something like
  2684 ``var x + var y + struct M'' as import;
  2685 
  2686 * Pure: improved thms_containing: proper indexing of facts instead of
  2687 raw theorems; check validity of results wrt. current name space;
  2688 include local facts of proof configuration (also covers active
  2689 locales), cover fixed variables in index; may use "_" in term
  2690 specification; an optional limit for the number of printed facts may
  2691 be given (the default is 40);
  2692 
  2693 * Pure: disallow duplicate fact bindings within new-style theory files
  2694 (batch-mode only);
  2695 
  2696 * Provers: improved induct method: assumptions introduced by case
  2697 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  2698 the goal statement); "foo" still refers to all facts collectively;
  2699 
  2700 * Provers: the function blast.overloaded has been removed: all constants
  2701 are regarded as potentially overloaded, which improves robustness in exchange
  2702 for slight decrease in efficiency;
  2703 
  2704 * Provers/linorder: New generic prover for transitivity reasoning over
  2705 linear orders.  Note: this prover is not efficient!
  2706 
  2707 * Isar: preview of problems to finish 'show' now produce an error
  2708 rather than just a warning (in interactive mode);
  2709 
  2710 
  2711 *** HOL ***
  2712 
  2713 * arith(_tac)
  2714 
  2715  - Produces a counter example if it cannot prove a goal.
  2716    Note that the counter example may be spurious if the goal is not a formula
  2717    of quantifier-free linear arithmetic.
  2718    In ProofGeneral the counter example appears in the trace buffer.
  2719 
  2720  - Knows about div k and mod k where k is a numeral of type nat or int.
  2721 
  2722  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  2723    linear arithmetic fails. This takes account of quantifiers and divisibility.
  2724    Presburger arithmetic can also be called explicitly via presburger(_tac).
  2725 
  2726 * simp's arithmetic capabilities have been enhanced a bit: it now
  2727 takes ~= in premises into account (by performing a case split);
  2728 
  2729 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  2730 are distributed over a sum of terms;
  2731 
  2732 * New tactic "trans_tac" and method "trans" instantiate
  2733 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  2734 "<=", "<" and "=").
  2735 
  2736 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  2737 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  2738 
  2739 * 'typedef' command has new option "open" to suppress the set
  2740 definition;
  2741 
  2742 * functions Min and Max on finite sets have been introduced (theory
  2743 Finite_Set);
  2744 
  2745 * attribute [symmetric] now works for relations as well; it turns
  2746 (x,y) : R^-1 into (y,x) : R, and vice versa;
  2747 
  2748 * induct over a !!-quantified statement (say !!x1..xn):
  2749   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  2750 
  2751 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  2752 %x. None. Warning: empty_def now refers to the previously hidden definition
  2753 of the empty set.
  2754 
  2755 * Algebra: formalization of classical algebra.  Intended as base for
  2756 any algebraic development in Isabelle.  Currently covers group theory
  2757 (up to Sylow's theorem) and ring theory (Universal Property of
  2758 Univariate Polynomials).  Contributions welcome;
  2759 
  2760 * GroupTheory: deleted, since its material has been moved to Algebra;
  2761 
  2762 * Complex: new directory of the complex numbers with numeric constants,
  2763 nonstandard complex numbers, and some complex analysis, standard and
  2764 nonstandard (Jacques Fleuriot);
  2765 
  2766 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  2767 
  2768 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  2769 Fleuriot);
  2770 
  2771 * Real/HahnBanach: updated and adapted to locales;
  2772 
  2773 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  2774 Gray and Kramer);
  2775 
  2776 * UNITY: added the Meier-Sanders theory of progress sets;
  2777 
  2778 * MicroJava: bytecode verifier and lightweight bytecode verifier
  2779 as abstract algorithms, instantiated to the JVM;
  2780 
  2781 * Bali: Java source language formalization. Type system, operational
  2782 semantics, axiomatic semantics. Supported language features:
  2783 classes, interfaces, objects,virtual methods, static methods,
  2784 static/instance fields, arrays, access modifiers, definite
  2785 assignment, exceptions.
  2786 
  2787 
  2788 *** ZF ***
  2789 
  2790 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  2791 universe, etc.);
  2792 
  2793 * Main ZF: virtually all theories converted to new-style format;
  2794 
  2795 
  2796 *** ML ***
  2797 
  2798 * Pure: Tactic.prove provides sane interface for internal proofs;
  2799 omits the infamous "standard" operation, so this is more appropriate
  2800 than prove_goalw_cterm in many situations (e.g. in simprocs);
  2801 
  2802 * Pure: improved error reporting of simprocs;
  2803 
  2804 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  2805 up simprocs;
  2806 
  2807 
  2808 *** Document preparation ***
  2809 
  2810 * uses \par instead of \\ for line breaks in theory text. This may
  2811 shift some page breaks in large documents. To get the old behaviour
  2812 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  2813 
  2814 * minimized dependencies of isabelle.sty and isabellesym.sty on
  2815 other packages
  2816 
  2817 * \<euro> now needs package babel/greek instead of marvosym (which
  2818 broke \Rightarrow)
  2819 
  2820 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  2821 textcomp package)
  2822 
  2823 
  2824 
  2825 New in Isabelle2002 (March 2002)
  2826 --------------------------------
  2827 
  2828 *** Document preparation ***
  2829 
  2830 * greatly simplified document preparation setup, including more
  2831 graceful interpretation of isatool usedir -i/-d/-D options, and more
  2832 instructive isatool mkdir; users should basically be able to get
  2833 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  2834 users may run a separate document processing stage manually like this:
  2835 "isatool usedir -D output HOL Test && isatool document Test/output";
  2836 
  2837 * theory dependency graph may now be incorporated into documents;
  2838 isatool usedir -g true will produce session_graph.eps/.pdf for use
  2839 with \includegraphics of LaTeX;
  2840 
  2841 * proper spacing of consecutive markup elements, especially text
  2842 blocks after section headings;
  2843 
  2844 * support bold style (for single symbols only), input syntax is like
  2845 this: "\<^bold>\<alpha>" or "\<^bold>A";
  2846 
  2847 * \<bullet> is now output as bold \cdot by default, which looks much
  2848 better in printed text;
  2849 
  2850 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  2851 note that these symbols are currently unavailable in Proof General /
  2852 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  2853 
  2854 * isatool latex no longer depends on changed TEXINPUTS, instead
  2855 isatool document copies the Isabelle style files to the target
  2856 location;
  2857 
  2858 
  2859 *** Isar ***
  2860 
  2861 * Pure/Provers: improved proof by cases and induction;
  2862   - 'case' command admits impromptu naming of parameters (such as
  2863     "case (Suc n)");
  2864   - 'induct' method divinates rule instantiation from the inductive
  2865     claim; no longer requires excessive ?P bindings for proper
  2866     instantiation of cases;
  2867   - 'induct' method properly enumerates all possibilities of set/type
  2868     rules; as a consequence facts may be also passed through *type*
  2869     rules without further ado;
  2870   - 'induct' method now derives symbolic cases from the *rulified*
  2871     rule (before it used to rulify cases stemming from the internal
  2872     atomized version); this means that the context of a non-atomic
  2873     statement becomes is included in the hypothesis, avoiding the
  2874     slightly cumbersome show "PROP ?case" form;
  2875   - 'induct' may now use elim-style induction rules without chaining
  2876     facts, using ``missing'' premises from the goal state; this allows
  2877     rules stemming from inductive sets to be applied in unstructured
  2878     scripts, while still benefitting from proper handling of non-atomic
  2879     statements; NB: major inductive premises need to be put first, all
  2880     the rest of the goal is passed through the induction;
  2881   - 'induct' proper support for mutual induction involving non-atomic
  2882     rule statements (uses the new concept of simultaneous goals, see
  2883     below);
  2884   - append all possible rule selections, but only use the first
  2885     success (no backtracking);
  2886   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  2887   - undeclared rule case names default to numbers 1, 2, 3, ...;
  2888   - added 'print_induct_rules' (covered by help item in recent Proof
  2889     General versions);
  2890   - moved induct/cases attributes to Pure, methods to Provers;
  2891   - generic method setup instantiated for FOL and HOL;
  2892 
  2893 * Pure: support multiple simultaneous goal statements, for example
  2894 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  2895 meta-level mechanism, this acts as if several individual goals had
  2896 been stated separately; in particular common proof methods need to be
  2897 repeated in order to cover all claims; note that a single elimination
  2898 step is *not* sufficient to establish the two conjunctions, so this
  2899 fails:
  2900 
  2901   assume "A & B" then have A and B ..   (*".." fails*)
  2902 
  2903 better use "obtain" in situations as above; alternative refer to
  2904 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  2905 
  2906 * Pure: proper integration with ``locales''; unlike the original
  2907 version by Florian Kammller, Isar locales package high-level proof
  2908 contexts rather than raw logical ones (e.g. we admit to include
  2909 attributes everywhere); operations on locales include merge and
  2910 rename; support for implicit arguments (``structures''); simultaneous
  2911 type-inference over imports and text; see also HOL/ex/Locales.thy for
  2912 some examples;
  2913 
  2914 * Pure: the following commands have been ``localized'', supporting a
  2915 target locale specification "(in name)": 'lemma', 'theorem',
  2916 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  2917 stored both within the locale and at the theory level (exported and
  2918 qualified by the locale name);
  2919 
  2920 * Pure: theory goals may now be specified in ``long'' form, with
  2921 ad-hoc contexts consisting of arbitrary locale elements. for example
  2922 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  2923 definitions may be given, too); the result is a meta-level rule with
  2924 the context elements being discharged in the obvious way;
  2925 
  2926 * Pure: new proof command 'using' allows to augment currently used
  2927 facts after a goal statement ('using' is syntactically analogous to
  2928 'apply', but acts on the goal's facts only); this allows chained facts
  2929 to be separated into parts given before and after a claim, as in
  2930 ``from a and b have C using d and e <proof>'';
  2931 
  2932 * Pure: renamed "antecedent" case to "rule_context";
  2933 
  2934 * Pure: new 'judgment' command records explicit information about the
  2935 object-logic embedding (used by several tools internally); no longer
  2936 use hard-wired "Trueprop";
  2937 
  2938 * Pure: added 'corollary' command;
  2939 
  2940 * Pure: fixed 'token_translation' command;
  2941 
  2942 * Pure: removed obsolete 'exported' attribute;
  2943 
  2944 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  2945 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  2946 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  2947 
  2948 * Pure: method 'atomize' presents local goal premises as object-level
  2949 statements (atomic meta-level propositions); setup controlled via
  2950 rewrite rules declarations of 'atomize' attribute; example
  2951 application: 'induct' method with proper rule statements in improper
  2952 proof *scripts*;
  2953 
  2954 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  2955 now consider the syntactic context of assumptions, giving a better
  2956 chance to get type-inference of the arguments right (this is
  2957 especially important for locales);
  2958 
  2959 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  2960 mode;
  2961 
  2962 * Pure/obtain: the formal conclusion "thesis", being marked as
  2963 ``internal'', may no longer be reference directly in the text;
  2964 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  2965 situations;
  2966 
  2967 * Pure: generic 'sym' attribute which declares a rule both as pure
  2968 'elim?' and for the 'symmetric' operation;
  2969 
  2970 * Pure: marginal comments ``--'' may now occur just anywhere in the
  2971 text; the fixed correlation with particular command syntax has been
  2972 discontinued;
  2973 
  2974 * Pure: new method 'rules' is particularly well-suited for proof
  2975 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  2976 but often produces more compact proof terms with less detours;
  2977 
  2978 * Pure/Provers/classical: simplified integration with pure rule
  2979 attributes and methods; the classical "intro?/elim?/dest?"
  2980 declarations coincide with the pure ones; the "rule" method no longer
  2981 includes classically swapped intros; "intro" and "elim" methods no
  2982 longer pick rules from the context; also got rid of ML declarations
  2983 AddXIs/AddXEs/AddXDs; all of this has some potential for
  2984 INCOMPATIBILITY;
  2985 
  2986 * Provers/classical: attribute 'swapped' produces classical inversions
  2987 of introduction rules;
  2988 
  2989 * Provers/simplifier: 'simplified' attribute may refer to explicit
  2990 rules instead of full simplifier context; 'iff' attribute handles
  2991 conditional rules;
  2992 
  2993 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  2994 
  2995 * HOL: 'recdef' now fails on unfinished automated proofs, use
  2996 "(permissive)" option to recover old behavior;
  2997 
  2998 * HOL: 'inductive' no longer features separate (collective) attributes
  2999 for 'intros' (was found too confusing);
  3000 
  3001 * HOL: properly declared induction rules less_induct and
  3002 wf_induct_rule;
  3003 
  3004 
  3005 *** HOL ***
  3006 
  3007 * HOL: moved over to sane numeral syntax; the new policy is as
  3008 follows:
  3009 
  3010   - 0 and 1 are polymorphic constants, which are defined on any
  3011   numeric type (nat, int, real etc.);
  3012 
  3013   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  3014   binary representation internally;
  3015 
  3016   - type nat has special constructor Suc, and generally prefers Suc 0
  3017   over 1::nat and Suc (Suc 0) over 2::nat;
  3018 
  3019 This change may cause significant problems of INCOMPATIBILITY; here
  3020 are some hints on converting existing sources:
  3021 
  3022   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  3023   entities, so expressions involving "-" (unary or binary minus) need
  3024   to be spaced properly;
  3025 
  3026   - existing occurrences of "1" may need to be constraint "1::nat" or
  3027   even replaced by Suc 0; similar for old "2";
  3028 
  3029   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  3030 
  3031   - remove all special provisions on numerals in proofs;
  3032 
  3033 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  3034 representation (depends on bin_arith_simps in the default context);
  3035 
  3036 * HOL: symbolic syntax for x^2 (numeral 2);
  3037 
  3038 * HOL: the class of all HOL types is now called "type" rather than
  3039 "term"; INCOMPATIBILITY, need to adapt references to this type class
  3040 in axclass/classes, instance/arities, and (usually rare) occurrences
  3041 in typings (of consts etc.); internally the class is called
  3042 "HOL.type", ML programs should refer to HOLogic.typeS;
  3043 
  3044 * HOL/record package improvements:
  3045   - new derived operations "fields" to build a partial record section,
  3046     "extend" to promote a fixed record to a record scheme, and
  3047     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  3048     declared as simp by default;
  3049   - shared operations ("more", "fields", etc.) now need to be always
  3050     qualified) --- potential INCOMPATIBILITY;
  3051   - removed "make_scheme" operations (use "make" with "extend") --
  3052     INCOMPATIBILITY;
  3053   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  3054   - provides cases/induct rules for use with corresponding Isar
  3055     methods (for concrete records, record schemes, concrete more
  3056     parts, and schematic more parts -- in that order);
  3057   - internal definitions directly based on a light-weight abstract
  3058     theory of product types over typedef rather than datatype;
  3059 
  3060 * HOL: generic code generator for generating executable ML code from
  3061 specifications; specific support for HOL constructs such as inductive
  3062 datatypes and sets, as well as recursive functions; can be invoked
  3063 via 'generate_code' theory section;
  3064 
  3065 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  3066 
  3067 * HOL: consolidated and renamed several theories.  In particular:
  3068         Ord.thy has been absorbed into HOL.thy
  3069         String.thy has been absorbed into List.thy
  3070 
  3071 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  3072 (beware of argument permutation!);
  3073 
  3074 * HOL: linorder_less_split superseded by linorder_cases;
  3075 
  3076 * HOL/List: "nodups" renamed to "distinct";
  3077 
  3078 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  3079 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  3080   - Ex_def has changed, now need to use some_eq_ex
  3081 
  3082 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  3083 in this (rare) case use:
  3084 
  3085   delSWrapper "split_all_tac"
  3086   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  3087 
  3088 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  3089 MAY FAIL;
  3090 
  3091 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  3092 Isabelle's type classes, ^ on functions and relations has too general
  3093 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  3094 necessary to attach explicit type constraints;
  3095 
  3096 * HOL/Relation: the prefix name of the infix "O" has been changed from
  3097 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  3098 renamed accordingly (eg "compI" -> "rel_compI").
  3099 
  3100 * HOL: syntax translations now work properly with numerals and records
  3101 expressions;
  3102 
  3103 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  3104 of "lam" -- INCOMPATIBILITY;
  3105 
  3106 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  3107 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  3108 renamed "Product_Type.unit";
  3109 
  3110 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  3111 
  3112 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  3113 the "cases" method);
  3114 
  3115 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  3116 Florian Kammller);
  3117 
  3118 * HOL/IMP: updated and converted to new-style theory format; several
  3119 parts turned into readable document, with proper Isar proof texts and
  3120 some explanations (by Gerwin Klein);
  3121 
  3122 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  3123 
  3124 * HOL-Hyperreal is now a logic image;
  3125 
  3126 
  3127 *** HOLCF ***
  3128 
  3129 * Isar: consts/constdefs supports mixfix syntax for continuous
  3130 operations;
  3131 
  3132 * Isar: domain package adapted to new-style theory format, e.g. see
  3133 HOLCF/ex/Dnat.thy;
  3134 
  3135 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  3136 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  3137 lift.induct_tac, always use UU instead of Undef;
  3138 
  3139 * HOLCF/IMP: updated and converted to new-style theory;
  3140 
  3141 
  3142 *** ZF ***
  3143 
  3144 * Isar: proper integration of logic-specific tools and packages,
  3145 including theory commands '(co)inductive', '(co)datatype',
  3146 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  3147 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  3148 
  3149 * theory Main no longer includes AC; for the Axiom of Choice, base
  3150 your theory on Main_ZFC;
  3151 
  3152 * the integer library now covers quotients and remainders, with many
  3153 laws relating division to addition, multiplication, etc.;
  3154 
  3155 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  3156 typeless version of the formalism;
  3157 
  3158 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  3159 format;
  3160 
  3161 * ZF/Induct: new directory for examples of inductive definitions,
  3162 including theory Multiset for multiset orderings; converted to
  3163 new-style theory format;
  3164 
  3165 * ZF: many new theorems about lists, ordinals, etc.;
  3166 
  3167 
  3168 *** General ***
  3169 
  3170 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  3171 variable proof controls level of detail: 0 = no proofs (only oracle
  3172 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  3173 also ref manual for further ML interfaces;
  3174 
  3175 * Pure/axclass: removed obsolete ML interface
  3176 goal_subclass/goal_arity;
  3177 
  3178 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  3179 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  3180 separate tokens, so expressions involving minus need to be spaced
  3181 properly;
  3182 
  3183 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  3184 rather than "infixl" or "infixr";
  3185 
  3186 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  3187 sort constraint specifications in type inference; e.g. "x::_::foo"
  3188 ensures that the type of "x" is of sort "foo" (but not necessarily a
  3189 type variable);
  3190 
  3191 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  3192 control output of nested => (types); the default behavior is
  3193 "type_brackets";
  3194 
  3195 * Pure/syntax: builtin parse translation for "_constify" turns valued
  3196 tokens into AST constants;
  3197 
  3198 * Pure/syntax: prefer later declarations of translations and print
  3199 translation functions; potential INCOMPATIBILITY: need to reverse
  3200 multiple declarations for same syntax element constant;
  3201 
  3202 * Pure/show_hyps reset by default (in accordance to existing Isar
  3203 practice);
  3204 
  3205 * Provers/classical: renamed addaltern to addafter, addSaltern to
  3206 addSafter;
  3207 
  3208 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  3209 as well;
  3210 
  3211 * system: tested support for MacOS X; should be able to get Isabelle +
  3212 Proof General to work in a plain Terminal after installing Poly/ML
  3213 (e.g. from the Isabelle distribution area) and GNU bash alone
  3214 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  3215 support requires further installations, e.g. from
  3216 http://fink.sourceforge.net/);
  3217 
  3218 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  3219 
  3220 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  3221 of 40 MB), cf. ML_OPTIONS;
  3222 
  3223 * system: Proof General keywords specification is now part of the
  3224 Isabelle distribution (see etc/isar-keywords.el);
  3225 
  3226 * system: support for persistent Proof General sessions (refrain from
  3227 outdating all loaded theories on startup); user may create writable
  3228 logic images like this: ``isabelle -q HOL Test'';
  3229 
  3230 * system: smart selection of Isabelle process versus Isabelle
  3231 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  3232 run both "isabelle" and "Isabelle" even if file names are badly
  3233 damaged (executable inspects the case of the first letter of its own
  3234 name); added separate "isabelle-process" and "isabelle-interface";
  3235 
  3236 * system: refrain from any attempt at filtering input streams; no
  3237 longer support ``8bit'' encoding of old isabelle font, instead proper
  3238 iso-latin characters may now be used; the related isatools
  3239 "symbolinput" and "nonascii" have disappeared as well;
  3240 
  3241 * system: removed old "xterm" interface (the print modes "xterm" and
  3242 "xterm_color" are still available for direct use in a suitable
  3243 terminal);
  3244 
  3245 
  3246 
  3247 New in Isabelle99-2 (February 2001)
  3248 -----------------------------------
  3249 
  3250 *** Overview of INCOMPATIBILITIES ***
  3251 
  3252 * HOL: please note that theories in the Library and elsewhere often use the
  3253 new-style (Isar) format; to refer to their theorems in an ML script you must
  3254 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  3255 
  3256 * HOL: inductive package no longer splits induction rule aggressively,
  3257 but only as far as specified by the introductions given; the old
  3258 format may be recovered via ML function complete_split_rule or attribute
  3259 'split_rule (complete)';
  3260 
  3261 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  3262 gfp_Tarski to gfp_unfold;
  3263 
  3264 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  3265 
  3266 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  3267 relation); infix "^^" has been renamed "``"; infix "``" has been
  3268 renamed "`"; "univalent" has been renamed "single_valued";
  3269 
  3270 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  3271 operation;
  3272 
  3273 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  3274 
  3275 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  3276 
  3277 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  3278 consequence, it is no longer monotonic wrt. the local goal context
  3279 (which is now passed through the inductive cases);
  3280 
  3281 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  3282 \<gg> to \<ggreater>;
  3283 
  3284 
  3285 *** Document preparation ***
  3286 
  3287 * \isabellestyle{NAME} selects version of Isabelle output (currently
  3288 available: are "it" for near math-mode best-style output, "sl" for
  3289 slanted text style, and "tt" for plain type-writer; if no
  3290 \isabellestyle command is given, output is according to slanted
  3291 type-writer);
  3292 
  3293 * support sub/super scripts (for single symbols only), input syntax is
  3294 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  3295 
  3296 * some more standard symbols; see Appendix A of the system manual for
  3297 the complete list of symbols defined in isabellesym.sty;
  3298 
  3299 * improved isabelle style files; more abstract symbol implementation
  3300 (should now use \isamath{...} and \isatext{...} in custom symbol
  3301 definitions);
  3302 
  3303 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  3304 state; Note that presentation of goal states does not conform to
  3305 actual human-readable proof documents.  Please do not include goal
  3306 states into document output unless you really know what you are doing!
  3307 
  3308 * proper indentation of antiquoted output with proportional LaTeX
  3309 fonts;
  3310 
  3311 * no_document ML operator temporarily disables LaTeX document
  3312 generation;
  3313 
  3314 * isatool unsymbolize tunes sources for plain ASCII communication;
  3315 
  3316 
  3317 *** Isar ***
  3318 
  3319 * Pure: Isar now suffers initial goal statements to contain unbound
  3320 schematic variables (this does not conform to actual readable proof
  3321 documents, due to unpredictable outcome and non-compositional proof
  3322 checking); users who know what they are doing may use schematic goals
  3323 for Prolog-style synthesis of proven results;
  3324 
  3325 * Pure: assumption method (an implicit finishing) now handles actual
  3326 rules as well;
  3327 
  3328 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  3329 initial goal, declare "that" only as Pure intro (only for single
  3330 steps); the "that" rule assumption may now be involved in implicit
  3331 finishing, thus ".." becomes a feasible for trivial obtains;
  3332 
  3333 * Pure: default proof step now includes 'intro_classes'; thus trivial
  3334 instance proofs may be performed by "..";
  3335 
  3336 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  3337 statements as well;
  3338 
  3339 * Pure: more robust selection of calculational rules;
  3340 
  3341 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  3342 rule (as well as the assumption rule);
  3343 
  3344 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  3345 lemmas, using the graph browser tool;
  3346 
  3347 * Pure: predict failure of "show" in interactive mode;
  3348 
  3349 * Pure: 'thms_containing' now takes actual terms as arguments;
  3350 
  3351 * HOL: improved method 'induct' --- now handles non-atomic goals
  3352 (potential INCOMPATIBILITY); tuned error handling;
  3353 
  3354 * HOL: cases and induct rules now provide explicit hints about the
  3355 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  3356 any remaining facts are inserted into the goal verbatim;
  3357 
  3358 * HOL: local contexts (aka cases) may now contain term bindings as
  3359 well; the 'cases' and 'induct' methods new provide a ?case binding for
  3360 the result to be shown in each case;
  3361 
  3362 * HOL: added 'recdef_tc' command;
  3363 
  3364 * isatool convert assists in eliminating legacy ML scripts;
  3365 
  3366 
  3367 *** HOL ***
  3368 
  3369 * HOL/Library: a collection of generic theories to be used together
  3370 with main HOL; the theory loader path already includes this directory
  3371 by default; the following existing theories have been moved here:
  3372 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  3373 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  3374 
  3375 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  3376 modelling and verification task performed in Isabelle/HOL +
  3377 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  3378 
  3379 * HOL/Algebra: special summation operator SUM no longer exists, it has
  3380 been replaced by setsum; infix 'assoc' now has priority 50 (like
  3381 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  3382 'domain', this makes the theory consistent with mathematical
  3383 literature;
  3384 
  3385 * HOL basics: added overloaded operations "inverse" and "divide"
  3386 (infix "/"), syntax for generic "abs" operation, generic summation
  3387 operator \<Sum>;
  3388 
  3389 * HOL/typedef: simplified package, provide more useful rules (see also
  3390 HOL/subset.thy);
  3391 
  3392 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  3393 now expressed as a proper nested rule (old-style tactic scripts may
  3394 require atomize_strip_tac to cope with non-atomic premises);
  3395 
  3396 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  3397 to "split_conv" (old name still available for compatibility);
  3398 
  3399 * HOL: improved concrete syntax for strings (e.g. allows translation
  3400 rules with string literals);
  3401 
  3402 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  3403  and Fleuriot's mechanization of analysis, including the transcendental
  3404  functions for the reals;
  3405 
  3406 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  3407 
  3408 
  3409 *** CTT ***
  3410 
  3411 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  3412 "lam" is displayed as TWO lambda-symbols
  3413 
  3414 * CTT: theory Main now available, containing everything (that is, Bool
  3415 and Arith);
  3416 
  3417 
  3418 *** General ***
  3419 
  3420 * Pure: the Simplifier has been implemented properly as a derived rule
  3421 outside of the actual kernel (at last!); the overall performance
  3422 penalty in practical applications is about 50%, while reliability of
  3423 the Isabelle inference kernel has been greatly improved;
  3424 
  3425 * print modes "brackets" and "no_brackets" control output of nested =>
  3426 (types) and ==> (props); the default behaviour is "brackets";
  3427 
  3428 * Provers: fast_tac (and friends) now handle actual object-logic rules
  3429 as assumptions as well;
  3430 
  3431 * system: support Poly/ML 4.0;
  3432 
  3433 * system: isatool install handles KDE version 1 or 2;
  3434 
  3435 
  3436 
  3437 New in Isabelle99-1 (October 2000)
  3438 ----------------------------------
  3439 
  3440 *** Overview of INCOMPATIBILITIES ***
  3441 
  3442 * HOL: simplification of natural numbers is much changed; to partly
  3443 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  3444 issue the following ML commands:
  3445 
  3446   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  3447   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  3448 
  3449 * HOL: simplification no longer dives into case-expressions; this is
  3450 controlled by "t.weak_case_cong" for each datatype t;
  3451 
  3452 * HOL: nat_less_induct renamed to less_induct;
  3453 
  3454 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  3455 fixsome to patch .thy and .ML sources automatically;
  3456 
  3457   select_equality  -> some_equality
  3458   select_eq_Ex     -> some_eq_ex
  3459   selectI2EX       -> someI2_ex
  3460   selectI2         -> someI2
  3461   selectI          -> someI
  3462   select1_equality -> some1_equality
  3463   Eps_sym_eq       -> some_sym_eq_trivial
  3464   Eps_eq           -> some_eq_trivial
  3465 
  3466 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  3467 
  3468 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  3469 instead);
  3470 
  3471 * HOL: the recursion equations generated by 'recdef' are now called
  3472 f.simps instead of f.rules;
  3473 
  3474 * HOL: qed_spec_mp now also handles bounded ALL as well;
  3475 
  3476 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  3477 sometimes be needed;
  3478 
  3479 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  3480 
  3481 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  3482 
  3483 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  3484 product is now "<*>" instead of "Times"; the lexicographic product is
  3485 now "<*lex*>" instead of "**";
  3486 
  3487 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  3488 of main HOL, but was unused); better use HOL's datatype package;
  3489 
  3490 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  3491 the old syntax may be recovered as follows:
  3492 
  3493   syntax (symbols)
  3494     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  3495       (infixl "\\<oplus>" 100)
  3496 
  3497 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3498 
  3499 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  3500 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  3501 internally;
  3502 
  3503 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  3504 changed from A/r to A//r;
  3505 
  3506 * ZF: new treatment of arithmetic (nat & int) may break some old
  3507 proofs;
  3508 
  3509 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  3510 rulify -> rule_format, elimify -> elim_format, ...);
  3511 
  3512 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3513 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  3514 should have to change intro!! to intro? only); replaced "delrule" by
  3515 "rule del";
  3516 
  3517 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  3518 
  3519 * Provers: strengthened force_tac by using new first_best_tac;
  3520 
  3521 * LaTeX document preparation: several changes of isabelle.sty (see
  3522 lib/texinputs);
  3523 
  3524 
  3525 *** Document preparation ***
  3526 
  3527 * formal comments (text blocks etc.) in new-style theories may now
  3528 contain antiquotations of thm/prop/term/typ/text to be presented
  3529 according to latex print mode; concrete syntax is like this:
  3530 @{term[show_types] "f(x) = a + x"};
  3531 
  3532 * isatool mkdir provides easy setup of Isabelle session directories,
  3533 including proper document sources;
  3534 
  3535 * generated LaTeX sources are now deleted after successful run
  3536 (isatool document -c); may retain a copy somewhere else via -D option
  3537 of isatool usedir;
  3538 
  3539 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  3540 style files, achieving self-contained LaTeX sources and simplifying
  3541 LaTeX debugging;
  3542 
  3543 * old-style theories now produce (crude) LaTeX output as well;
  3544 
  3545 * browser info session directories are now self-contained (may be put
  3546 on WWW server seperately); improved graphs of nested sessions; removed
  3547 graph for 'all sessions';
  3548 
  3549 * several improvements in isabelle style files; \isabellestyle{it}
  3550 produces fake math mode output; \isamarkupheader is now \section by
  3551 default; see lib/texinputs/isabelle.sty etc.;
  3552 
  3553 
  3554 *** Isar ***
  3555 
  3556 * Isar/Pure: local results and corresponding term bindings are now
  3557 subject to Hindley-Milner polymorphism (similar to ML); this
  3558 accommodates incremental type-inference very nicely;
  3559 
  3560 * Isar/Pure: new derived language element 'obtain' supports
  3561 generalized existence reasoning;
  3562 
  3563 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  3564 support accumulation of results, without applying any rules yet;
  3565 useful to collect intermediate results without explicit name
  3566 references, and for use with transitivity rules with more than 2
  3567 premises;
  3568 
  3569 * Isar/Pure: scalable support for case-analysis type proofs: new
  3570 'case' language element refers to local contexts symbolically, as
  3571 produced by certain proof methods; internally, case names are attached
  3572 to theorems as "tags";
  3573 
  3574 * Isar/Pure: theory command 'hide' removes declarations from
  3575 class/type/const name spaces;
  3576 
  3577 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  3578 indicate potential overloading;
  3579 
  3580 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  3581 
  3582 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  3583 "{a,b,c}" instead of {a,b,c};
  3584 
  3585 * Isar/Pure now provides its own version of intro/elim/dest
  3586 attributes; useful for building new logics, but beware of confusion
  3587 with the version in Provers/classical;
  3588 
  3589 * Isar/Pure: the local context of (non-atomic) goals is provided via
  3590 case name 'antecedent';
  3591 
  3592 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  3593 to the current context is now done automatically);
  3594 
  3595 * Isar/Pure: theory command 'method_setup' provides a simple interface
  3596 for definining proof methods in ML;
  3597 
  3598 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3599 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  3600 most cases, one should have to change intro!! to intro? only);
  3601 replaced "delrule" by "rule del";
  3602 
  3603 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  3604 'symmetric' attribute (the latter supercedes [RS sym]);
  3605 
  3606 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  3607 method modifier); 'simp' method: 'only:' modifier removes loopers as
  3608 well (including splits);
  3609 
  3610 * Isar/Provers: Simplifier and Classical methods now support all kind
  3611 of modifiers used in the past, including 'cong', 'iff', etc.
  3612 
  3613 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  3614 of Simplifier and Classical reasoner);
  3615 
  3616 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  3617 now support named cases; major packages (inductive, datatype, primrec,
  3618 recdef) support case names and properly name parameters;
  3619 
  3620 * Isar/HOL: new transitivity rules for substitution in inequalities --
  3621 monotonicity conditions are extracted to be proven at end of
  3622 calculations;
  3623 
  3624 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  3625 method anyway;
  3626 
  3627 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  3628 split_if split_if_asm; datatype package provides theorems foo.splits =
  3629 foo.split foo.split_asm for each datatype;
  3630 
  3631 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  3632 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  3633 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  3634 use "(cases (simplified))" method in proper proof texts);
  3635 
  3636 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  3637 
  3638 * Isar: names of theorems etc. may be natural numbers as well;
  3639 
  3640 * Isar: 'pr' command: optional arguments for goals_limit and
  3641 ProofContext.prems_limit; no longer prints theory contexts, but only
  3642 proof states;
  3643 
  3644 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  3645 additional print modes to be specified; e.g. "pr(latex)" will print
  3646 proof state according to the Isabelle LaTeX style;
  3647 
  3648 * Isar: improved support for emulating tactic scripts, including proof
  3649 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  3650 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  3651 (for HOL datatypes);
  3652 
  3653 * Isar: simplified (more robust) goal selection of proof methods: 1st
  3654 goal, all goals, or explicit goal specifier (tactic emulation); thus
  3655 'proof method scripts' have to be in depth-first order;
  3656 
  3657 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  3658 
  3659 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  3660 should instead use individual commands for printing items
  3661 (print_commands, print_methods etc.);
  3662 
  3663 * Isar: added 'nothing' --- the empty list of theorems;
  3664 
  3665 
  3666 *** HOL ***
  3667 
  3668 * HOL/MicroJava: formalization of a fragment of Java, together with a
  3669 corresponding virtual machine and a specification of its bytecode
  3670 verifier and a lightweight bytecode verifier, including proofs of
  3671 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  3672 Cornelia Pusch (see also the homepage of project Bali at
  3673 http://isabelle.in.tum.de/Bali/);
  3674 
  3675 * HOL/Algebra: new theory of rings and univariate polynomials, by
  3676 Clemens Ballarin;
  3677 
  3678 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  3679 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  3680 Rasmussen;
  3681 
  3682 * HOL/Lattice: fundamental concepts of lattice theory and order
  3683 structures, including duals, properties of bounds versus algebraic
  3684 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  3685 Theorem for complete lattices etc.; may also serve as a demonstration
  3686 for abstract algebraic reasoning using axiomatic type classes, and
  3687 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  3688 
  3689 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  3690 von Oheimb;
  3691 
  3692 * HOL/IMPP: extension of IMP with local variables and mutually
  3693 recursive procedures, by David von Oheimb;
  3694 
  3695 * HOL/Lambda: converted into new-style theory and document;
  3696 
  3697 * HOL/ex/Multiquote: example of multiple nested quotations and
  3698 anti-quotations -- basically a generalized version of de-Bruijn
  3699 representation; very useful in avoiding lifting of operations;
  3700 
  3701 * HOL/record: added general record equality rule to simpset; fixed
  3702 select-update simplification procedure to handle extended records as
  3703 well; admit "r" as field name;
  3704 
  3705 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  3706 other numeric types and also as the identity of groups, rings, etc.;
  3707 
  3708 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  3709 Types nat and int belong to this axclass;
  3710 
  3711 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  3712    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  3713    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  3714   two terms #m*u and #n*u are replaced by #(m+n)*u
  3715     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  3716   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  3717     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  3718 
  3719 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  3720 powerful prover for predicate logic but knows nothing of clasets; see
  3721 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  3722 
  3723 * HOL: new version of "case_tac" subsumes both boolean case split and
  3724 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  3725 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  3726 
  3727 * HOL: simplification no longer dives into case-expressions: only the
  3728 selector expression is simplified, but not the remaining arms; to
  3729 enable full simplification of case-expressions for datatype t, you may
  3730 remove t.weak_case_cong from the simpset, either globally (Delcongs
  3731 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  3732 
  3733 * HOL/recdef: the recursion equations generated by 'recdef' for
  3734 function 'f' are now called f.simps instead of f.rules; if all
  3735 termination conditions are proved automatically, these simplification
  3736 rules are added to the simpset, as in primrec; rules may be named
  3737 individually as well, resulting in a separate list of theorems for
  3738 each equation;
  3739 
  3740 * HOL/While is a new theory that provides a while-combinator. It
  3741 permits the definition of tail-recursive functions without the
  3742 provision of a termination measure. The latter is necessary once the
  3743 invariant proof rule for while is applied.
  3744 
  3745 * HOL: new (overloaded) notation for the set of elements below/above
  3746 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  3747 
  3748 * HOL: theorems impI, allI, ballI bound as "strip";
  3749 
  3750 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  3751 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  3752 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  3753 
  3754 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3755 
  3756 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  3757 main HOL, but was unused);
  3758 
  3759 * HOL: fewer consts declared as global (e.g. have to refer to
  3760 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  3761 
  3762 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  3763 in case of overlap with user translations (e.g. judgements over
  3764 tuples); (note that the underlying logical represenation is still
  3765 bogus);
  3766 
  3767 
  3768 *** ZF ***
  3769 
  3770 * ZF: simplification automatically cancels common terms in arithmetic
  3771 expressions over nat and int;
  3772 
  3773 * ZF: new treatment of nat to minimize type-checking: all operators
  3774 coerce their operands to a natural number using the function natify,
  3775 making the algebraic laws unconditional;
  3776 
  3777 * ZF: as above, for int: operators coerce their operands to an integer
  3778 using the function intify;
  3779 
  3780 * ZF: the integer library now contains many of the usual laws for the
  3781 orderings, including $<=, and monotonicity laws for $+ and $*;
  3782 
  3783 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  3784 simplification;
  3785 
  3786 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  3787 to the simplifier and classical reasoner simultaneously;
  3788 
  3789 
  3790 *** General ***
  3791 
  3792 * Provers: blast_tac now handles actual object-logic rules as
  3793 assumptions; note that auto_tac uses blast_tac internally as well;
  3794 
  3795 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  3796 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  3797 
  3798 * Provers: delrules now handles destruct rules as well (no longer need
  3799 explicit make_elim);
  3800 
  3801 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  3802   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3803 use instead the strong form,
  3804   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3805 in HOL, FOL and ZF the function cla_make_elim will create such rules
  3806 from destruct-rules;
  3807 
  3808 * Provers: Simplifier.easy_setup provides a fast path to basic
  3809 Simplifier setup for new object-logics;
  3810 
  3811 * Pure: AST translation rules no longer require constant head on LHS;
  3812 
  3813 * Pure: improved name spaces: ambiguous output is qualified; support
  3814 for hiding of names;
  3815 
  3816 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  3817 XSYMBOL_HOME; no longer need to do manual configuration in most
  3818 situations;
  3819 
  3820 * system: compression of ML heaps images may now be controlled via -c
  3821 option of isabelle and isatool usedir (currently only observed by
  3822 Poly/ML);
  3823 
  3824 * system: isatool installfonts may handle X-Symbol fonts as well (very
  3825 useful for remote X11);
  3826 
  3827 * system: provide TAGS file for Isabelle sources;
  3828 
  3829 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  3830 order;
  3831 
  3832 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  3833 timing flag supersedes proof_timing and Toplevel.trace;
  3834 
  3835 * ML: new combinators |>> and |>>> for incremental transformations
  3836 with secondary results (e.g. certain theory extensions):
  3837 
  3838 * ML: PureThy.add_defs gets additional argument to indicate potential
  3839 overloading (usually false);
  3840 
  3841 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  3842 results;
  3843 
  3844 
  3845 
  3846 New in Isabelle99 (October 1999)
  3847 --------------------------------
  3848 
  3849 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3850 
  3851 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  3852 are no longer simplified.  (This allows the simplifier to unfold recursive
  3853 functional programs.)  To restore the old behaviour, declare
  3854 
  3855     Delcongs [if_weak_cong];
  3856 
  3857 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  3858 complement;
  3859 
  3860 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  3861 
  3862 * HOL/datatype: mutual_induct_tac no longer exists --
  3863   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  3864 
  3865 * HOL/typedef: fixed type inference for representing set; type
  3866 arguments now have to occur explicitly on the rhs as type constraints;
  3867 
  3868 * ZF: The con_defs part of an inductive definition may no longer refer
  3869 to constants declared in the same theory;
  3870 
  3871 * HOL, ZF: the function mk_cases, generated by the inductive
  3872 definition package, has lost an argument.  To simplify its result, it
  3873 uses the default simpset instead of a supplied list of theorems.
  3874 
  3875 * HOL/List: the constructors of type list are now Nil and Cons;
  3876 
  3877 * Simplifier: the type of the infix ML functions
  3878         setSSolver addSSolver setSolver addSolver
  3879 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  3880 for packaging solvers. A solver is created via
  3881         mk_solver: string -> (thm list -> int -> tactic) -> solver
  3882 where the string argument is only a comment.
  3883 
  3884 
  3885 *** Proof tools ***
  3886 
  3887 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  3888 decision procedure for linear arithmetic. Currently it is used for
  3889 types `nat', `int', and `real' in HOL (see below); it can, should and
  3890 will be instantiated for other types and logics as well.
  3891 
  3892 * The simplifier now accepts rewrite rules with flexible heads, eg
  3893      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  3894   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  3895   matching.
  3896 
  3897 
  3898 *** General ***
  3899 
  3900 * New Isabelle/Isar subsystem provides an alternative to traditional
  3901 tactical theorem proving; together with the ProofGeneral/isar user
  3902 interface it offers an interactive environment for developing human
  3903 readable proof documents (Isar == Intelligible semi-automated
  3904 reasoning); for further information see isatool doc isar-ref,
  3905 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  3906 
  3907 * improved and simplified presentation of theories: better HTML markup
  3908 (including colors), graph views in several sizes; isatool usedir now
  3909 provides a proper interface for user theories (via -P option); actual
  3910 document preparation based on (PDF)LaTeX is available as well (for
  3911 new-style theories only); see isatool doc system for more information;
  3912 
  3913 * native support for Proof General, both for classic Isabelle and
  3914 Isabelle/Isar;
  3915 
  3916 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  3917 using the graph browser tool;
  3918 
  3919 * Isabelle manuals now also available as PDF;
  3920 
  3921 * theory loader rewritten from scratch (may not be fully
  3922 bug-compatible); old loadpath variable has been replaced by show_path,
  3923 add_path, del_path, reset_path functions; new operations such as
  3924 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  3925 isatool doc ref);
  3926 
  3927 * improved isatool install: option -k creates KDE application icon,
  3928 option -p DIR installs standalone binaries;
  3929 
  3930 * added ML_PLATFORM setting (useful for cross-platform installations);
  3931 more robust handling of platform specific ML images for SML/NJ;
  3932 
  3933 * the settings environment is now statically scoped, i.e. it is never
  3934 created again in sub-processes invoked from isabelle, isatool, or
  3935 Isabelle;
  3936 
  3937 * path element specification '~~' refers to '$ISABELLE_HOME';
  3938 
  3939 * in locales, the "assumes" and "defines" parts may be omitted if
  3940 empty;
  3941 
  3942 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  3943 long arrows);
  3944 
  3945 * new print_mode "HTML";
  3946 
  3947 * new flag show_tags controls display of tags of theorems (which are
  3948 basically just comments that may be attached by some tools);
  3949 
  3950 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  3951 mode and goal output format:
  3952 
  3953 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  3954 244c244
  3955 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  3956 ---
  3957 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  3958 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  3959 181c181
  3960 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  3961 ---
  3962 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  3963 
  3964 * function bind_thms stores lists of theorems (cf. bind_thm);
  3965 
  3966 * new shorthand tactics ftac, eatac, datac, fatac;
  3967 
  3968 * qed (and friends) now accept "" as result name; in that case the
  3969 theorem is not stored, but proper checks and presentation of the
  3970 result still apply;
  3971 
  3972 * theorem database now also indexes constants "Trueprop", "all",
  3973 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  3974 
  3975 
  3976 *** HOL ***
  3977 
  3978 ** HOL arithmetic **
  3979 
  3980 * There are now decision procedures for linear arithmetic over nat and
  3981 int:
  3982 
  3983 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  3984 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  3985 are treated as atomic; subformulae not involving type `nat' or `int'
  3986 are ignored; quantified subformulae are ignored unless they are
  3987 positive universal or negative existential. The tactic has to be
  3988 invoked by hand and can be a little bit slow. In particular, the
  3989 running time is exponential in the number of occurrences of `min' and
  3990 `max', and `-' on `nat'.
  3991 
  3992 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  3993 (negated) (in)equalities among the premises and the conclusion into
  3994 account (i.e. no compound formulae) and does not know about `min' and
  3995 `max', and `-' on `nat'. It is fast and is used automatically by the
  3996 simplifier.
  3997 
  3998 NB: At the moment, these decision procedures do not cope with mixed
  3999 nat/int formulae where the two parts interact, such as `m < n ==>
  4000 int(m) < int(n)'.
  4001 
  4002 * HOL/Numeral provides a generic theory of numerals (encoded
  4003 efficiently as bit strings); setup for types nat/int/real is in place;
  4004 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  4005 int, existing theories and proof scripts may require a few additional
  4006 type constraints;
  4007 
  4008 * integer division and remainder can now be performed on constant
  4009 arguments;
  4010 
  4011 * many properties of integer multiplication, division and remainder
  4012 are now available;
  4013 
  4014 * An interface to the Stanford Validity Checker (SVC) is available through the
  4015 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  4016 are proved automatically.  SVC must be installed separately, and its results
  4017 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  4018 invocation of the underlying oracle).  For SVC see
  4019   http://verify.stanford.edu/SVC
  4020 
  4021 * IsaMakefile: the HOL-Real target now builds an actual image;
  4022 
  4023 
  4024 ** HOL misc **
  4025 
  4026 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  4027 (in Isabelle/Isar) -- by Gertrud Bauer;
  4028 
  4029 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  4030 analysis for assembly languages with subtypes;
  4031 
  4032 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  4033 -- avoids syntactic ambiguities and treats state, transition, and
  4034 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  4035 changed syntax and (many) tactics;
  4036 
  4037 * HOL/inductive: Now also handles more general introduction rules such
  4038   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  4039   theorems are now maintained within the theory (maintained via the
  4040   "mono" attribute);
  4041 
  4042 * HOL/datatype: Now also handles arbitrarily branching datatypes
  4043   (using function types) such as
  4044 
  4045   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  4046 
  4047 * HOL/record: record_simproc (part of the default simpset) takes care
  4048 of selectors applied to updated records; record_split_tac is no longer
  4049 part of the default claset; update_defs may now be removed from the
  4050 simpset in many cases; COMPATIBILITY: old behavior achieved by
  4051 
  4052   claset_ref () := claset() addSWrapper record_split_wrapper;
  4053   Delsimprocs [record_simproc]
  4054 
  4055 * HOL/typedef: fixed type inference for representing set; type
  4056 arguments now have to occur explicitly on the rhs as type constraints;
  4057 
  4058 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  4059 names rather than an ML expression;
  4060 
  4061 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  4062 supplied later.  Program schemes can be defined, such as
  4063     "While B C s = (if B s then While B C (C s) else s)"
  4064 where the well-founded relation can be chosen after B and C have been given.
  4065 
  4066 * HOL/List: the constructors of type list are now Nil and Cons;
  4067 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  4068 course, ML tools referring to List.list.op # etc. have to be adapted;
  4069 
  4070 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  4071 disabled by default; run isabelle with option -m HOL to get back to
  4072 the original Gordon/HOL-style output;
  4073 
  4074 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  4075 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  4076 
  4077 * HOL basic syntax simplified (more orthogonal): all variants of
  4078 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  4079 Eps operator is provided as well: "SOME x. P[x]";
  4080 
  4081 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  4082 
  4083 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  4084 thus available for user theories;
  4085 
  4086 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  4087 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  4088 time;
  4089 
  4090 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  4091 several times and then mp;
  4092 
  4093 
  4094 *** LK ***
  4095 
  4096 * the notation <<...>> is now available as a notation for sequences of
  4097 formulas;
  4098 
  4099 * the simplifier is now installed
  4100 
  4101 * the axiom system has been generalized (thanks to Soren Heilmann)
  4102 
  4103 * the classical reasoner now has a default rule database
  4104 
  4105 
  4106 *** ZF ***
  4107 
  4108 * new primrec section allows primitive recursive functions to be given
  4109 directly (as in HOL) over datatypes and the natural numbers;
  4110 
  4111 * new tactics induct_tac and exhaust_tac for induction (or case
  4112 analysis) over datatypes and the natural numbers;
  4113 
  4114 * the datatype declaration of type T now defines the recursor T_rec;
  4115 
  4116 * simplification automatically does freeness reasoning for datatype
  4117 constructors;
  4118 
  4119 * automatic type-inference, with AddTCs command to insert new
  4120 type-checking rules;
  4121 
  4122 * datatype introduction rules are now added as Safe Introduction rules
  4123 to the claset;
  4124 
  4125 * the syntax "if P then x else y" is now available in addition to
  4126 if(P,x,y);
  4127 
  4128 
  4129 *** Internal programming interfaces ***
  4130 
  4131 * tuned simplifier trace output; new flag debug_simp;
  4132 
  4133 * structures Vartab / Termtab (instances of TableFun) offer efficient
  4134 tables indexed by indexname_ord / term_ord (compatible with aconv);
  4135 
  4136 * AxClass.axclass_tac lost the theory argument;
  4137 
  4138 * tuned current_goals_markers semantics: begin / end goal avoids
  4139 printing empty lines;
  4140 
  4141 * removed prs and prs_fn hook, which was broken because it did not
  4142 include \n in its semantics, forcing writeln to add one
  4143 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  4144 string -> unit if you really want to output text without newline;
  4145 
  4146 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  4147 plain output, interface builders may have to enable 'isabelle_font'
  4148 mode to get Isabelle font glyphs as before;
  4149 
  4150 * refined token_translation interface; INCOMPATIBILITY: output length
  4151 now of type real instead of int;
  4152 
  4153 * theory loader actions may be traced via new ThyInfo.add_hook
  4154 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  4155 your own database of information attached to *whole* theories -- as
  4156 opposed to intra-theory data slots offered via TheoryDataFun;
  4157 
  4158 * proper handling of dangling sort hypotheses (at last!);
  4159 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  4160 extra sort hypotheses that can be witnessed from the type signature;
  4161 the force_strip_shyps flag is gone, any remaining shyps are simply
  4162 left in the theorem (with a warning issued by strip_shyps_warning);
  4163 
  4164 
  4165 
  4166 New in Isabelle98-1 (October 1998)
  4167 ----------------------------------
  4168 
  4169 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4170 
  4171 * several changes of automated proof tools;
  4172 
  4173 * HOL: major changes to the inductive and datatype packages, including
  4174 some minor incompatibilities of theory syntax;
  4175 
  4176 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  4177 called `inj_on';
  4178 
  4179 * HOL: removed duplicate thms in Arith:
  4180   less_imp_add_less  should be replaced by  trans_less_add1
  4181   le_imp_add_le      should be replaced by  trans_le_add1
  4182 
  4183 * HOL: unary minus is now overloaded (new type constraints may be
  4184 required);
  4185 
  4186 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  4187 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  4188 now taken as an integer constant.
  4189 
  4190 * Pure: ML function 'theory_of' renamed to 'theory';
  4191 
  4192 
  4193 *** Proof tools ***
  4194 
  4195 * Simplifier:
  4196   1. Asm_full_simp_tac is now more aggressive.
  4197      1. It will sometimes reorient premises if that increases their power to
  4198         simplify.
  4199      2. It does no longer proceed strictly from left to right but may also
  4200         rotate premises to achieve further simplification.
  4201      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  4202      old Asm_full_simp_tac in that it does not rotate premises.
  4203   2. The simplifier now knows a little bit about nat-arithmetic.
  4204 
  4205 * Classical reasoner: wrapper mechanism for the classical reasoner now
  4206 allows for selected deletion of wrappers, by introduction of names for
  4207 wrapper functionals.  This implies that addbefore, addSbefore,
  4208 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  4209 and that adding two tactics with the same name overwrites the first
  4210 one (emitting a warning).
  4211   type wrapper = (int -> tactic) -> (int -> tactic)
  4212   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  4213   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  4214   delWrapper, delSWrapper: claset *  string            -> claset
  4215   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  4216 
  4217 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  4218 semantics; addbefore now affects only the unsafe part of step_tac
  4219 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  4220 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  4221 by Force_tac;
  4222 
  4223 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  4224 compWrapper; added safe wrapper (and access functions for it);
  4225 
  4226 * HOL/split_all_tac is now much faster and fails if there is nothing
  4227 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  4228 and the names of the automatically generated variables have changed.
  4229 split_all_tac has moved within claset() from unsafe wrappers to safe
  4230 wrappers, which means that !!-bound variables are split much more
  4231 aggressively, and safe_tac and clarify_tac now split such variables.
  4232 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  4233 Note: the same holds for record_split_tac, which does the job of
  4234 split_all_tac for record fields.
  4235 
  4236 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  4237 permanently to the default simpset using Addsplits just like
  4238 Addsimps. They can be removed via Delsplits just like
  4239 Delsimps. Lower-case versions are also available.
  4240 
  4241 * HOL/Simplifier: The rule split_if is now part of the default
  4242 simpset. This means that the simplifier will eliminate all occurrences
  4243 of if-then-else in the conclusion of a goal. To prevent this, you can
  4244 either remove split_if completely from the default simpset by
  4245 `Delsplits [split_if]' or remove it in a specific call of the
  4246 simplifier using `... delsplits [split_if]'.  You can also add/delete
  4247 other case splitting rules to/from the default simpset: every datatype
  4248 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  4249 t is the name of the datatype).
  4250 
  4251 * Classical reasoner / Simplifier combination: new force_tac (and
  4252 derivatives Force_tac, force) combines rewriting and classical
  4253 reasoning (and whatever other tools) similarly to auto_tac, but is
  4254 aimed to solve the given subgoal completely.
  4255 
  4256 
  4257 *** General ***
  4258 
  4259 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  4260 and `goalw': the theory is no longer needed as an explicit argument -
  4261 the current theory context is used; assumptions are no longer returned
  4262 at the ML-level unless one of them starts with ==> or !!; it is
  4263 recommended to convert to these new commands using isatool fixgoal
  4264 (backup your sources first!);
  4265 
  4266 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  4267 the current theory context, and 'theory' to lookup stored theories;
  4268 
  4269 * new theory section 'locale' for declaring constants, assumptions and
  4270 definitions that have local scope;
  4271 
  4272 * new theory section 'nonterminals' for purely syntactic types;
  4273 
  4274 * new theory section 'setup' for generic ML setup functions
  4275 (e.g. package initialization);
  4276 
  4277 * the distribution now includes Isabelle icons: see
  4278 lib/logo/isabelle-{small,tiny}.xpm;
  4279 
  4280 * isatool install - install binaries with absolute references to
  4281 ISABELLE_HOME/bin;
  4282 
  4283 * isatool logo -- create instances of the Isabelle logo (as EPS);
  4284 
  4285 * print mode 'emacs' reserved for Isamode;
  4286 
  4287 * support multiple print (ast) translations per constant name;
  4288 
  4289 * theorems involving oracles are now printed with a suffixed [!];
  4290 
  4291 
  4292 *** HOL ***
  4293 
  4294 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  4295 
  4296 * HOL/inductive package reorganized and improved: now supports mutual
  4297 definitions such as
  4298 
  4299   inductive EVEN ODD
  4300     intrs
  4301       null "0 : EVEN"
  4302       oddI "n : EVEN ==> Suc n : ODD"
  4303       evenI "n : ODD ==> Suc n : EVEN"
  4304 
  4305 new theorem list "elims" contains an elimination rule for each of the
  4306 recursive sets; inductive definitions now handle disjunctive premises
  4307 correctly (also ZF);
  4308 
  4309 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  4310 "mutual_induct" no longer exists - the induction rule is always
  4311 contained in "induct";
  4312 
  4313 
  4314 * HOL/datatype package re-implemented and greatly improved: now
  4315 supports mutually recursive datatypes such as
  4316 
  4317   datatype
  4318     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  4319             | SUM ('a aexp) ('a aexp)
  4320             | DIFF ('a aexp) ('a aexp)
  4321             | NUM 'a
  4322   and
  4323     'a bexp = LESS ('a aexp) ('a aexp)
  4324             | AND ('a bexp) ('a bexp)
  4325             | OR ('a bexp) ('a bexp)
  4326 
  4327 as well as indirectly recursive datatypes such as
  4328 
  4329   datatype
  4330     ('a, 'b) term = Var 'a
  4331                   | App 'b ((('a, 'b) term) list)
  4332 
  4333 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  4334 induction on mutually / indirectly recursive datatypes.
  4335 
  4336 Primrec equations are now stored in theory and can be accessed via
  4337 <function_name>.simps.
  4338 
  4339 INCOMPATIBILITIES:
  4340 
  4341   - Theories using datatypes must now have theory Datatype as an
  4342     ancestor.
  4343   - The specific <typename>.induct_tac no longer exists - use the
  4344     generic induct_tac instead.
  4345   - natE has been renamed to nat.exhaust - use exhaust_tac
  4346     instead of res_inst_tac ... natE. Note that the variable
  4347     names in nat.exhaust differ from the names in natE, this
  4348     may cause some "fragile" proofs to fail.
  4349   - The theorems split_<typename>_case and split_<typename>_case_asm
  4350     have been renamed to <typename>.split and <typename>.split_asm.
  4351   - Since default sorts of type variables are now handled correctly,
  4352     some datatype definitions may have to be annotated with explicit
  4353     sort constraints.
  4354   - Primrec definitions no longer require function name and type
  4355     of recursive argument.
  4356 
  4357 Consider using isatool fixdatatype to adapt your theories and proof
  4358 scripts to the new package (backup your sources first!).
  4359 
  4360 
  4361 * HOL/record package: considerably improved implementation; now
  4362 includes concrete syntax for record types, terms, updates; theorems
  4363 for surjective pairing and splitting !!-bound record variables; proof
  4364 support is as follows:
  4365 
  4366   1) standard conversions (selectors or updates applied to record
  4367 constructor terms) are part of the standard simpset;
  4368 
  4369   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  4370 made part of standard simpset and claset via addIffs;
  4371 
  4372   3) a tactic for record field splitting (record_split_tac) is part of
  4373 the standard claset (addSWrapper);
  4374 
  4375 To get a better idea about these rules you may retrieve them via
  4376 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  4377 the name of your record type.
  4378 
  4379 The split tactic 3) conceptually simplifies by the following rule:
  4380 
  4381   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  4382 
  4383 Thus any record variable that is bound by meta-all will automatically
  4384 blow up into some record constructor term, consequently the
  4385 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  4386 solve record problems automatically.
  4387 
  4388 
  4389 * reorganized the main HOL image: HOL/Integ and String loaded by
  4390 default; theory Main includes everything;
  4391 
  4392 * automatic simplification of integer sums and comparisons, using cancellation;
  4393 
  4394 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  4395 
  4396 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  4397 
  4398 * many new identities for unions, intersections, set difference, etc.;
  4399 
  4400 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  4401 called split_if, split_split, split_sum_case and split_nat_case (to go
  4402 with add/delsplits);
  4403 
  4404 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  4405 (?x::unit) = (); this is made part of the default simpset, which COULD
  4406 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  4407 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  4408 unit_abs_eta_conv is added in order to counter the effect of
  4409 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  4410 %u.f();
  4411 
  4412 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  4413 makes more sense);
  4414 
  4415 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4416   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4417   disjointness reasoning but breaking a few old proofs.
  4418 
  4419 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  4420 to 'converse' from 'inverse' (for compatibility with ZF and some
  4421 literature);
  4422 
  4423 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  4424 the well-founded relation;
  4425 
  4426 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  4427     Compl A.  The "Compl" syntax remains available as input syntax for this
  4428     release ONLY.
  4429 
  4430 * HOL/Update: new theory of function updates:
  4431     f(a:=b) == %x. if x=a then b else f x
  4432 may also be iterated as in f(a:=b,c:=d,...);
  4433 
  4434 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  4435 
  4436 * HOL/List:
  4437   - new function list_update written xs[i:=v] that updates the i-th
  4438     list position. May also be iterated as in xs[i:=a,j:=b,...].
  4439   - new function `upt' written [i..j(] which generates the list
  4440     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  4441     bound write [i..j], which is a shorthand for [i..j+1(].
  4442   - new lexicographic orderings and corresponding wellfoundedness theorems.
  4443 
  4444 * HOL/Arith:
  4445   - removed 'pred' (predecessor) function;
  4446   - generalized some theorems about n-1;
  4447   - many new laws about "div" and "mod";
  4448   - new laws about greatest common divisors (see theory ex/Primes);
  4449 
  4450 * HOL/Relation: renamed the relational operator r^-1 "converse"
  4451 instead of "inverse";
  4452 
  4453 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  4454   of the multiset ordering;
  4455 
  4456 * directory HOL/Real: a construction of the reals using Dedekind cuts
  4457   (not included by default);
  4458 
  4459 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  4460 
  4461 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  4462   programs, i.e. different program variables may have different types.
  4463 
  4464 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4465   [previously, this check worked only if the rewrite rule was unconditional]
  4466   Now rew can involve either definitions or equalities (either == or =).
  4467 
  4468 
  4469 *** ZF ***
  4470 
  4471 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  4472   only the theorems proved on ZF.ML;
  4473 
  4474 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4475   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4476   disjointness reasoning but breaking a few old proofs.
  4477 
  4478 * ZF/Update: new theory of function updates
  4479     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  4480   may also be iterated as in f(a:=b,c:=d,...);
  4481 
  4482 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  4483 
  4484 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4485   [previously, this check worked only if the rewrite rule was unconditional]
  4486   Now rew can involve either definitions or equalities (either == or =).
  4487 
  4488 * case_tac provided for compatibility with HOL
  4489     (like the old excluded_middle_tac, but with subgoals swapped)
  4490 
  4491 
  4492 *** Internal programming interfaces ***
  4493 
  4494 * Pure: several new basic modules made available for general use, see
  4495 also src/Pure/README;
  4496 
  4497 * improved the theory data mechanism to support encapsulation (data
  4498 kind name replaced by private Object.kind, acting as authorization
  4499 key); new type-safe user interface via functor TheoryDataFun; generic
  4500 print_data function becomes basically useless;
  4501 
  4502 * removed global_names compatibility flag -- all theory declarations
  4503 are qualified by default;
  4504 
  4505 * module Pure/Syntax now offers quote / antiquote translation
  4506 functions (useful for Hoare logic etc. with implicit dependencies);
  4507 see HOL/ex/Antiquote for an example use;
  4508 
  4509 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  4510 cterm -> thm;
  4511 
  4512 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  4513 subgoal;
  4514 
  4515 * Display.print_goals function moved to Locale.print_goals;
  4516 
  4517 * standard print function for goals supports current_goals_markers
  4518 variable for marking begin of proof, end of proof, start of goal; the
  4519 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  4520 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  4521 for example;
  4522 
  4523 
  4524 
  4525 New in Isabelle98 (January 1998)
  4526 --------------------------------
  4527 
  4528 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4529 
  4530 * changed lexical syntax of terms / types: dots made part of long
  4531 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  4532 
  4533 * simpset (and claset) reference variable replaced by functions
  4534 simpset / simpset_ref;
  4535 
  4536 * no longer supports theory aliases (via merge) and non-trivial
  4537 implicit merge of thms' signatures;
  4538 
  4539 * most internal names of constants changed due to qualified names;
  4540 
  4541 * changed Pure/Sequence interface (see Pure/seq.ML);
  4542 
  4543 
  4544 *** General Changes ***
  4545 
  4546 * hierachically structured name spaces (for consts, types, axms, thms
  4547 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  4548 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  4549 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  4550 long_names for fully qualified output names; NOTE: ML programs
  4551 (special tactics, packages etc.) referring to internal names may have
  4552 to be adapted to cope with fully qualified names; in case of severe
  4553 backward campatibility problems try setting 'global_names' at compile
  4554 time to have enrything declared within a flat name space; one may also
  4555 fine tune name declarations in theories via the 'global' and 'local'
  4556 section;
  4557 
  4558 * reimplemented the implicit simpset and claset using the new anytype
  4559 data filed in signatures; references simpset:simpset ref etc. are
  4560 replaced by functions simpset:unit->simpset and
  4561 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  4562 to patch your ML files accordingly;
  4563 
  4564 * HTML output now includes theory graph data for display with Java
  4565 applet or isatool browser; data generated automatically via isatool
  4566 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  4567 
  4568 * defs may now be conditional; improved rewrite_goals_tac to handle
  4569 conditional equations;
  4570 
  4571 * defs now admits additional type arguments, using TYPE('a) syntax;
  4572 
  4573 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  4574 creates a new theory node; implicit merge of thms' signatures is
  4575 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  4576 transfer:theory->thm->thm in (rare) cases;
  4577 
  4578 * improved handling of draft signatures / theories; draft thms (and
  4579 ctyps, cterms) are automatically promoted to real ones;
  4580 
  4581 * slightly changed interfaces for oracles: admit many per theory, named
  4582 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  4583 
  4584 * print_goals: optional output of const types (set show_consts and
  4585 show_types);
  4586 
  4587 * improved output of warnings (###) and errors (***);
  4588 
  4589 * subgoal_tac displays a warning if the new subgoal has type variables;
  4590 
  4591 * removed old README and Makefiles;
  4592 
  4593 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  4594 
  4595 * removed obsolete init_pps and init_database;
  4596 
  4597 * deleted the obsolete tactical STATE, which was declared by
  4598     fun STATE tacfun st = tacfun st st;
  4599 
  4600 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  4601 (which abbreviates $HOME);
  4602 
  4603 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  4604 use isatool fixseq to adapt your ML programs (this works for fully
  4605 qualified references to the Sequence structure only!);
  4606 
  4607 * use_thy no longer requires writable current directory; it always
  4608 reloads .ML *and* .thy file, if either one is out of date;
  4609 
  4610 
  4611 *** Classical Reasoner ***
  4612 
  4613 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  4614 tactics that use classical reasoning to simplify a subgoal without
  4615 splitting it into several subgoals;
  4616 
  4617 * Safe_tac: like safe_tac but uses the default claset;
  4618 
  4619 
  4620 *** Simplifier ***
  4621 
  4622 * added simplification meta rules:
  4623     (asm_)(full_)simplify: simpset -> thm -> thm;
  4624 
  4625 * simplifier.ML no longer part of Pure -- has to be loaded by object
  4626 logics (again);
  4627 
  4628 * added prems argument to simplification procedures;
  4629 
  4630 * HOL, FOL, ZF: added infix function `addsplits':
  4631   instead of `<simpset> setloop (split_tac <thms>)'
  4632   you can simply write `<simpset> addsplits <thms>'
  4633 
  4634 
  4635 *** Syntax ***
  4636 
  4637 * TYPE('a) syntax for type reflection terms;
  4638 
  4639 * no longer handles consts with name "" -- declare as 'syntax' instead;
  4640 
  4641 * pretty printer: changed order of mixfix annotation preference (again!);
  4642 
  4643 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  4644 
  4645 
  4646 *** HOL ***
  4647 
  4648 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4649   with `addloop' of the simplifier to faciliate case splitting in premises.
  4650 
  4651 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  4652 
  4653 * HOL/Auth: new protocol proofs including some for the Internet
  4654   protocol TLS;
  4655 
  4656 * HOL/Map: new theory of `maps' a la VDM;
  4657 
  4658 * HOL/simplifier: simplification procedures nat_cancel_sums for
  4659 cancelling out common nat summands from =, <, <= (in)equalities, or
  4660 differences; simplification procedures nat_cancel_factor for
  4661 cancelling common factor from =, <, <= (in)equalities over natural
  4662 sums; nat_cancel contains both kinds of procedures, it is installed by
  4663 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  4664 
  4665 * HOL/simplifier: terms of the form
  4666   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  4667   are rewritten to
  4668   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  4669   and those of the form
  4670   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  4671   are rewritten to
  4672   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  4673 
  4674 * HOL/datatype
  4675   Each datatype `t' now comes with a theorem `split_t_case' of the form
  4676 
  4677   P(t_case f1 ... fn x) =
  4678      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  4679         ...
  4680        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  4681      )
  4682 
  4683   and a theorem `split_t_case_asm' of the form
  4684 
  4685   P(t_case f1 ... fn x) =
  4686     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  4687         ...
  4688        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  4689      )
  4690   which can be added to a simpset via `addsplits'. The existing theorems
  4691   expand_list_case and expand_option_case have been renamed to
  4692   split_list_case and split_option_case.
  4693 
  4694 * HOL/Arithmetic:
  4695   - `pred n' is automatically converted to `n-1'.
  4696     Users are strongly encouraged not to use `pred' any longer,
  4697     because it will disappear altogether at some point.
  4698   - Users are strongly encouraged to write "0 < n" rather than
  4699     "n ~= 0". Theorems and proof tools have been modified towards this
  4700     `standard'.
  4701 
  4702 * HOL/Lists:
  4703   the function "set_of_list" has been renamed "set" (and its theorems too);
  4704   the function "nth" now takes its arguments in the reverse order and
  4705   has acquired the infix notation "!" as in "xs!n".
  4706 
  4707 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  4708 
  4709 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  4710   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  4711 
  4712 * HOL/record: extensible records with schematic structural subtyping
  4713 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  4714 still lacks various theorems and concrete record syntax;
  4715 
  4716 
  4717 *** HOLCF ***
  4718 
  4719 * removed "axioms" and "generated by" sections;
  4720 
  4721 * replaced "ops" section by extended "consts" section, which is capable of
  4722   handling the continuous function space "->" directly;
  4723 
  4724 * domain package:
  4725   . proves theorems immediately and stores them in the theory,
  4726   . creates hierachical name space,
  4727   . now uses normal mixfix annotations (instead of cinfix...),
  4728   . minor changes to some names and values (for consistency),
  4729   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  4730   . separator between mutual domain defs: changed "," to "and",
  4731   . improved handling of sort constraints;  now they have to
  4732     appear on the left-hand side of the equations only;
  4733 
  4734 * fixed LAM <x,y,zs>.b syntax;
  4735 
  4736 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  4737 adm (%x. P (t x)), where P is chainfinite and t continuous;
  4738 
  4739 
  4740 *** FOL and ZF ***
  4741 
  4742 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4743   with `addloop' of the simplifier to faciliate case splitting in premises.
  4744 
  4745 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  4746 in HOL, they strip ALL and --> from proved theorems;
  4747 
  4748 
  4749 
  4750 New in Isabelle94-8 (May 1997)
  4751 ------------------------------
  4752 
  4753 *** General Changes ***
  4754 
  4755 * new utilities to build / run / maintain Isabelle etc. (in parts
  4756 still somewhat experimental); old Makefiles etc. still functional;
  4757 
  4758 * new 'Isabelle System Manual';
  4759 
  4760 * INSTALL text, together with ./configure and ./build scripts;
  4761 
  4762 * reimplemented type inference for greater efficiency, better error
  4763 messages and clean internal interface;
  4764 
  4765 * prlim command for dealing with lots of subgoals (an easier way of
  4766 setting goals_limit);
  4767 
  4768 
  4769 *** Syntax ***
  4770 
  4771 * supports alternative (named) syntax tables (parser and pretty
  4772 printer); internal interface is provided by add_modesyntax(_i);
  4773 
  4774 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  4775 be used in conjunction with the Isabelle symbol font; uses the
  4776 "symbols" syntax table;
  4777 
  4778 * added token_translation interface (may translate name tokens in
  4779 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  4780 the current print_mode); IMPORTANT: user print translation functions
  4781 are responsible for marking newly introduced bounds
  4782 (Syntax.mark_boundT);
  4783 
  4784 * token translations for modes "xterm" and "xterm_color" that display
  4785 names in bold, underline etc. or colors (which requires a color
  4786 version of xterm);
  4787 
  4788 * infixes may now be declared with names independent of their syntax;
  4789 
  4790 * added typed_print_translation (like print_translation, but may
  4791 access type of constant);
  4792 
  4793 
  4794 *** Classical Reasoner ***
  4795 
  4796 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  4797 some limitations.  Blast_tac...
  4798   + ignores addss, addbefore, addafter; this restriction is intrinsic
  4799   + ignores elimination rules that don't have the correct format
  4800         (the conclusion MUST be a formula variable)
  4801   + ignores types, which can make HOL proofs fail
  4802   + rules must not require higher-order unification, e.g. apply_type in ZF
  4803     [message "Function Var's argument not a bound variable" relates to this]
  4804   + its proof strategy is more general but can actually be slower
  4805 
  4806 * substitution with equality assumptions no longer permutes other
  4807 assumptions;
  4808 
  4809 * minor changes in semantics of addafter (now called addaltern); renamed
  4810 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  4811 (and access functions for it);
  4812 
  4813 * improved combination of classical reasoner and simplifier:
  4814   + functions for handling clasimpsets
  4815   + improvement of addss: now the simplifier is called _after_ the
  4816     safe steps.
  4817   + safe variant of addss called addSss: uses safe simplifications
  4818     _during_ the safe steps. It is more complete as it allows multiple
  4819     instantiations of unknowns (e.g. with slow_tac).
  4820 
  4821 *** Simplifier ***
  4822 
  4823 * added interface for simplification procedures (functions that
  4824 produce *proven* rewrite rules on the fly, depending on current
  4825 redex);
  4826 
  4827 * ordering on terms as parameter (used for ordered rewriting);
  4828 
  4829 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  4830 
  4831 * the solver is now split into a safe and an unsafe part.
  4832 This should be invisible for the normal user, except that the
  4833 functions setsolver and addsolver have been renamed to setSolver and
  4834 addSolver; added safe_asm_full_simp_tac;
  4835 
  4836 
  4837 *** HOL ***
  4838 
  4839 * a generic induction tactic `induct_tac' which works for all datatypes and
  4840 also for type `nat';
  4841 
  4842 * a generic case distinction tactic `exhaust_tac' which works for all
  4843 datatypes and also for type `nat';
  4844 
  4845 * each datatype comes with a function `size';
  4846 
  4847 * patterns in case expressions allow tuple patterns as arguments to
  4848 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  4849 
  4850 * primrec now also works with type nat;
  4851 
  4852 * recdef: a new declaration form, allows general recursive functions to be
  4853 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  4854 
  4855 * the constant for negation has been renamed from "not" to "Not" to
  4856 harmonize with FOL, ZF, LK, etc.;
  4857 
  4858 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  4859 infinite lists;
  4860 
  4861 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  4862 
  4863 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  4864 problems in commutative rings, using axiomatic type classes for + and *;
  4865 
  4866 * more examples in HOL/MiniML and HOL/Auth;
  4867 
  4868 * more default rewrite rules for quantifiers, union/intersection;
  4869 
  4870 * a new constant `arbitrary == @x.False';
  4871 
  4872 * HOLCF/IOA replaces old HOL/IOA;
  4873 
  4874 * HOLCF changes: derived all rules and arities
  4875   + axiomatic type classes instead of classes
  4876   + typedef instead of faking type definitions
  4877   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  4878   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  4879   + eliminated the types void, one, tr
  4880   + use unit lift and bool lift (with translations) instead of one and tr
  4881   + eliminated blift from Lift3.thy (use Def instead of blift)
  4882   all eliminated rules are derived as theorems --> no visible changes ;
  4883 
  4884 
  4885 *** ZF ***
  4886 
  4887 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  4888 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  4889 as ZF_cs addSIs [equalityI];
  4890 
  4891 
  4892 
  4893 New in Isabelle94-7 (November 96)
  4894 ---------------------------------
  4895 
  4896 * allowing negative levels (as offsets) in prlev and choplev;
  4897 
  4898 * super-linear speedup for large simplifications;
  4899 
  4900 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  4901 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  4902 FAIL); can suppress it using the command Delsimps (ex_simps @
  4903 all_simps); De Morgan laws are also now included, by default;
  4904 
  4905 * improved printing of ==>  :  ~:
  4906 
  4907 * new object-logic "Sequents" adds linear logic, while replacing LK
  4908 and Modal (thanks to Sara Kalvala);
  4909 
  4910 * HOL/Auth: correctness proofs for authentication protocols;
  4911 
  4912 * HOL: new auto_tac combines rewriting and classical reasoning (many
  4913 examples on HOL/Auth);
  4914 
  4915 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  4916 the rewriter and classical reasoner simultaneously;
  4917 
  4918 * function uresult no longer returns theorems in "standard" format;
  4919 regain previous version by: val uresult = standard o uresult;
  4920 
  4921 
  4922 
  4923 New in Isabelle94-6
  4924 -------------------
  4925 
  4926 * oracles -- these establish an interface between Isabelle and trusted
  4927 external reasoners, which may deliver results as theorems;
  4928 
  4929 * proof objects (in particular record all uses of oracles);
  4930 
  4931 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  4932 
  4933 * "constdefs" section in theory files;
  4934 
  4935 * "primrec" section (HOL) no longer requires names;
  4936 
  4937 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  4938 
  4939 
  4940 
  4941 New in Isabelle94-5
  4942 -------------------
  4943 
  4944 * reduced space requirements;
  4945 
  4946 * automatic HTML generation from theories;
  4947 
  4948 * theory files no longer require "..." (quotes) around most types;
  4949 
  4950 * new examples, including two proofs of the Church-Rosser theorem;
  4951 
  4952 * non-curried (1994) version of HOL is no longer distributed;
  4953 
  4954 
  4955 
  4956 New in Isabelle94-4
  4957 -------------------
  4958 
  4959 * greatly reduced space requirements;
  4960 
  4961 * theory files (.thy) no longer require \...\ escapes at line breaks;
  4962 
  4963 * searchable theorem database (see the section "Retrieving theorems" on
  4964 page 8 of the Reference Manual);
  4965 
  4966 * new examples, including Grabczewski's monumental case study of the
  4967 Axiom of Choice;
  4968 
  4969 * The previous version of HOL renamed to Old_HOL;
  4970 
  4971 * The new version of HOL (previously called CHOL) uses a curried syntax
  4972 for functions.  Application looks like f a b instead of f(a,b);
  4973 
  4974 * Mutually recursive inductive definitions finally work in HOL;
  4975 
  4976 * In ZF, pattern-matching on tuples is now available in all abstractions and
  4977 translates to the operator "split";
  4978 
  4979 
  4980 
  4981 New in Isabelle94-3
  4982 -------------------
  4983 
  4984 * new infix operator, addss, allowing the classical reasoner to
  4985 perform simplification at each step of its search.  Example:
  4986         fast_tac (cs addss ss)
  4987 
  4988 * a new logic, CHOL, the same as HOL, but with a curried syntax
  4989 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  4990 look like (a,b) instead of <a,b>;
  4991 
  4992 * PLEASE NOTE: CHOL will eventually replace HOL!
  4993 
  4994 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  4995 It translates to the operator "split".  A new theory of integers is available;
  4996 
  4997 * In ZF, integer numerals now denote two's-complement binary integers.
  4998 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  4999 
  5000 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  5001 of the Axiom of Choice;
  5002 
  5003 
  5004 
  5005 New in Isabelle94-2
  5006 -------------------
  5007 
  5008 * Significantly faster resolution;
  5009 
  5010 * the different sections in a .thy file can now be mixed and repeated
  5011 freely;
  5012 
  5013 * Database of theorems for FOL, HOL and ZF.  New
  5014 commands including qed, qed_goal and bind_thm store theorems in the database.
  5015 
  5016 * Simple database queries: return a named theorem (get_thm) or all theorems of
  5017 a given theory (thms_of), or find out what theory a theorem was proved in
  5018 (theory_of_thm);
  5019 
  5020 * Bugs fixed in the inductive definition and datatype packages;
  5021 
  5022 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  5023 and HOL_dup_cs obsolete;
  5024 
  5025 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  5026 have been removed;
  5027 
  5028 * Simpler definition of function space in ZF;
  5029 
  5030 * new results about cardinal and ordinal arithmetic in ZF;
  5031 
  5032 * 'subtype' facility in HOL for introducing new types as subsets of existing
  5033 types;
  5034 
  5035 :mode=text:wrap=hard:maxLineLen=72:
  5036 $Id$