NEWS
author wenzelm
Tue May 08 17:40:18 2007 +0200 (2007-05-08)
changeset 22871 9ffb43b19ec6
parent 22863 e1d3fa78b8e1
child 22921 475ff421a6a3
permissions -rw-r--r--
tuned;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     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).
    12 
    13 * Theory syntax: the header format ``theory A = B + C:'' has been
    14 discontinued in favour of ``theory A imports B C begin''.  Use isatool
    15 fixheaders to convert existing theory files.  INCOMPATIBILITY.
    16 
    17 * Theory syntax: the old non-Isar theory file format has been
    18 discontinued altogether.  Note that ML proof scripts may still be used
    19 with Isar theories; migration is usually quite simple with the ML
    20 function use_legacy_bindings.  INCOMPATIBILITY.
    21 
    22 * Theory syntax: some popular names (e.g. 'class', 'declaration',
    23 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
    24 quotes.
    25 
    26 * Legacy goal package: reduced interface to the bare minimum required
    27 to keep existing proof scripts running.  Most other user-level
    28 functions are now part of the OldGoals structure, which is *not* open
    29 by default (consider isatool expandshort before open OldGoals).
    30 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
    31 these tend to cause confusion about the actual goal (!) context being
    32 used here, which is not necessarily the same as the_context().
    33 
    34 * Command 'find_theorems': support "*" wildcard in "name:" criterion.
    35 
    36 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
    37 by default, which means that "prems" (and also "fixed variables") are
    38 suppressed from proof state output.  Note that the ProofGeneral
    39 settings mechanism allows to change and save options persistently, but
    40 older versions of Isabelle will fail to start up if a negative prems
    41 limit is imposed.
    42 
    43 * Local theory targets may be specified by non-nested blocks of
    44 ``context/locale/class ... begin'' followed by ``end''.  The body may
    45 contain definitions, theorems etc., including any derived mechanism
    46 that has been implemented on top of these primitives.  This concept
    47 generalizes the existing ``theorem (in ...)'' towards more versatility
    48 and scalability.
    49 
    50 * Proof General interface: proper undo of final 'end' command;
    51 discontinued Isabelle/classic mode (ML proof scripts).
    52 
    53 
    54 *** Document preparation ***
    55 
    56 * Added antiquotation @{theory name} which prints the given name,
    57 after checking that it refers to a valid ancestor theory in the
    58 current context.
    59 
    60 * Added antiquotations @{ML_type text} and @{ML_struct text} which
    61 check the given source text as ML type/structure, printing verbatim.
    62 
    63 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
    64 "c args == rhs" given in the current context.  (Any number of
    65 arguments may be given on the LHS.)
    66 
    67 
    68 
    69 *** Pure ***
    70 
    71 * code generator: 
    72   - Isar "definition"s and primitive instance definitions are added explicitly
    73     to the table of defining equations
    74   - primitive definitions are not used as defining equations by default any longer
    75   - defining equations are now definitly restricted to meta "==" and object
    76         equality "="
    77   - HOL theories have been adopted accordingly
    78 
    79 * class_package.ML offers a combination of axclasses and locales to
    80 achieve Haskell-like type classes in Isabelle. See
    81 HOL/ex/Classpackage.thy for examples.
    82 
    83 * Yet another code generator framework allows to generate executable
    84 code for ML and Haskell (including "class"es). A short usage sketch:
    85 
    86     internal compilation:
    87         code_gen <list of constants (term syntax)> (SML #)
    88     writing SML code to a file:
    89         code_gen <list of constants (term syntax)> (SML <filename>)
    90     writing OCaml code to a file:
    91         code_gen <list of constants (term syntax)> (OCaml <filename>)
    92     writing Haskell code to a bunch of files:
    93         code_gen <list of constants (term syntax)> (Haskell <filename>)
    94 
    95 Reasonable default setup of framework in HOL/Main.
    96 
    97 Theorem attributs for selecting and transforming function equations theorems:
    98 
    99     [code fun]:        select a theorem as function equation for a specific constant
   100     [code fun del]:    deselect a theorem as function equation for a specific constant
   101     [code inline]:     select an equation theorem for unfolding (inlining) in place
   102     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
   103 
   104 User-defined serializations (target in {SML, OCaml, Haskell}):
   105 
   106     code_const <and-list of constants (term syntax)>
   107       {(target) <and-list of const target syntax>}+
   108 
   109     code_type <and-list of type constructors>
   110       {(target) <and-list of type target syntax>}+
   111 
   112     code_instance <and-list of instances>
   113       {(target)}+
   114         where instance ::= <type constructor> :: <class>
   115 
   116     code_class <and_list of classes>
   117       {(target) <and-list of class target syntax>}+
   118         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
   119 
   120 code_instance and code_class only apply to target Haskell.
   121 
   122 See HOL theories and HOL/ex/Codegenerator*.thy for usage examples.
   123 Doc/Isar/Advanced/Codegen/ provides a tutorial.
   124 
   125 * Command 'no_translations' removes translation rules from theory
   126 syntax.
   127 
   128 * Overloaded definitions are now actually checked for acyclic
   129 dependencies.  The overloading scheme is slightly more general than
   130 that of Haskell98, although Isabelle does not demand an exact
   131 correspondence to type class and instance declarations.
   132 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
   133 exotic versions of overloading -- at the discretion of the user!
   134 
   135 Polymorphic constants are represented via type arguments, i.e. the
   136 instantiation that matches an instance against the most general
   137 declaration given in the signature.  For example, with the declaration
   138 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
   139 as c(nat).  Overloading is essentially simultaneous structural
   140 recursion over such type arguments.  Incomplete specification patterns
   141 impose global constraints on all occurrences, e.g. c('a * 'a) on the
   142 LHS means that more general c('a * 'b) will be disallowed on any RHS.
   143 Command 'print_theory' outputs the normalized system of recursive
   144 equations, see section "definitions".
   145 
   146 * Isar: improper proof element 'guess' is like 'obtain', but derives
   147 the obtained context from the course of reasoning!  For example:
   148 
   149   assume "EX x y. A x & B y"   -- "any previous fact"
   150   then guess x and y by clarify
   151 
   152 This technique is potentially adventurous, depending on the facts and
   153 proof tools being involved here.
   154 
   155 * Isar: known facts from the proof context may be specified as literal
   156 propositions, using ASCII back-quote syntax.  This works wherever
   157 named facts used to be allowed so far, in proof commands, proof
   158 methods, attributes etc.  Literal facts are retrieved from the context
   159 according to unification of type and term parameters.  For example,
   160 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
   161 theorems in the current context, then these are valid literal facts:
   162 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
   163 
   164 There is also a proof method "fact" which does the same composition
   165 for explicit goal states, e.g. the following proof texts coincide with
   166 certain special cases of literal facts:
   167 
   168   have "A" by fact                 ==  note `A`
   169   have "A ==> B" by fact           ==  note `A ==> B`
   170   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
   171   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
   172 
   173 * Isar: ":" (colon) is no longer a symbolic identifier character in
   174 outer syntax.  Thus symbolic identifiers may be used without
   175 additional white space in declarations like this: ``assume *: A''.
   176 
   177 * Isar: 'print_facts' prints all local facts of the current context,
   178 both named and unnamed ones.
   179 
   180 * Isar: 'def' now admits simultaneous definitions, e.g.:
   181 
   182   def x == "t" and y == "u"
   183 
   184 * Isar: added command 'unfolding', which is structurally similar to
   185 'using', but affects both the goal state and facts by unfolding given
   186 rewrite rules.  Thus many occurrences of the 'unfold' method or
   187 'unfolded' attribute may be replaced by first-class proof text.
   188 
   189 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
   190 and command 'unfolding' now all support object-level equalities
   191 (potentially conditional).  The underlying notion of rewrite rule is
   192 analogous to the 'rule_format' attribute, but *not* that of the
   193 Simplifier (which is usually more generous).
   194 
   195 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
   196 method expression within a sandbox consisting of the first N
   197 sub-goals, which need to exist.  For example, ``simp_all [3]''
   198 simplifies the first three sub-goals, while (rule foo, simp_all)[]
   199 simplifies all new goals that emerge from applying rule foo to the
   200 originally first one.
   201 
   202 * Isar: schematic goals are no longer restricted to higher-order
   203 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
   204 expected.
   205 
   206 * Isar: the conclusion of a long theorem statement is now either
   207 'shows' (a simultaneous conjunction, as before), or 'obtains'
   208 (essentially a disjunction of cases with local parameters and
   209 assumptions).  The latter allows to express general elimination rules
   210 adequately; in this notation common elimination rules look like this:
   211 
   212   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
   213     assumes "EX x. P x"
   214     obtains x where "P x"
   215 
   216   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
   217     assumes "A & B"
   218     obtains A and B
   219 
   220   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
   221     assumes "A | B"
   222     obtains
   223       A
   224     | B
   225 
   226 The subsequent classical rules even refer to the formal "thesis"
   227 explicitly:
   228 
   229   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
   230     obtains "~ thesis"
   231 
   232   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
   233     obtains "thesis ==> something"
   234 
   235 The actual proof of an 'obtains' statement is analogous to that of the
   236 Isar proof element 'obtain', only that there may be several cases.
   237 Optional case names may be specified in parentheses; these will be
   238 available both in the present proof and as annotations in the
   239 resulting rule, for later use with the 'cases' method (cf. attribute
   240 case_names).
   241 
   242 * Isar: the assumptions of a long theorem statement are available as
   243 "assms" fact in the proof context.  This is more appropriate than the
   244 (historical) "prems", which refers to all assumptions of the current
   245 context, including those from the target locale, proof body etc.
   246 
   247 * Isar: 'print_statement' prints theorems from the current theory or
   248 proof context in long statement form, according to the syntax of a
   249 top-level lemma.
   250 
   251 * Isar: 'obtain' takes an optional case name for the local context
   252 introduction rule (default "that").
   253 
   254 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
   255 explicit (is "_ ==> ?foo") in the rare cases where this still happens
   256 to occur.
   257 
   258 * Pure: syntax "CONST name" produces a fully internalized constant
   259 according to the current context.  This is particularly useful for
   260 syntax translations that should refer to internal constant
   261 representations independently of name spaces.
   262 
   263 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
   264 instead of "FOO ". This allows multiple binder declarations to coexist
   265 in the same context.  INCOMPATIBILITY.
   266 
   267 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
   268 primitive that also works in a locale context (both for constants and
   269 fixed variables).  Type declaration and internal syntactic
   270 representation of given constants retrieved from the context.
   271 
   272 * Isar/locales: new derived specification elements 'axiomatization',
   273 'definition', 'abbreviation', which support type-inference, admit
   274 object-level specifications (equality, equivalence).  See also the
   275 isar-ref manual.  Examples:
   276 
   277   axiomatization
   278     eq  (infix "===" 50) where
   279     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
   280 
   281   definition "f x y = x + y + 1"
   282   definition g where "g x = f x x"
   283 
   284   abbreviation
   285     neq  (infix "=!=" 50) where
   286     "x =!= y == ~ (x === y)"
   287 
   288 These specifications may be also used in a locale context.  Then the
   289 constants being introduced depend on certain fixed parameters, and the
   290 constant name is qualified by the locale base name.  An internal
   291 abbreviation takes care for convenient input and output, making the
   292 parameters implicit and using the original short name.  See also
   293 HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
   294 entities from a monomorphic theory.
   295 
   296 Presently, abbreviations are only available 'in' a target locale, but
   297 not inherited by general import expressions.  Also note that
   298 'abbreviation' may be used as a type-safe replacement for 'syntax' +
   299 'translations' in common applications.
   300 
   301 Concrete syntax is attached to specified constants in internal form,
   302 independently of name spaces.  The parse tree representation is
   303 slightly different -- use 'notation' instead of raw 'syntax', and
   304 'translations' with explicit "CONST" markup to accommodate this.
   305 
   306 * Pure: command 'print_abbrevs' prints all constant abbreviations of
   307 the current context.  Print mode "no_abbrevs" prevents inversion of
   308 abbreviations on output.
   309 
   310 * Isar/locales: improved parameter handling:
   311 - use of locales "var" and "struct" no longer necessary;
   312 - parameter renamings are no longer required to be injective.
   313   This enables, for example, to define a locale for endomorphisms thus:
   314   locale endom = homom mult mult h.
   315 
   316 * Isar/locales: changed the way locales with predicates are defined.
   317 Instead of accumulating the specification, the imported expression is
   318 now an interpretation.  INCOMPATIBILITY: different normal form of
   319 locale expressions.  In particular, in interpretations of locales with
   320 predicates, goals repesenting already interpreted fragments are not
   321 removed automatically.  Use methods `intro_locales' and
   322 `unfold_locales'; see below.
   323 
   324 * Isar/locales: new methods `intro_locales' and `unfold_locales'
   325 provide backward reasoning on locales predicates.  The methods are
   326 aware of interpretations and discharge corresponding goals.
   327 `intro_locales' is less aggressive then `unfold_locales' and does not
   328 unfold predicates to assumptions.
   329 
   330 * Isar/locales: the order in which locale fragments are accumulated
   331 has changed.  This enables to override declarations from fragments due
   332 to interpretations -- for example, unwanted simp rules.
   333 
   334 * Provers/induct: improved internal context management to support
   335 local fixes and defines on-the-fly.  Thus explicit meta-level
   336 connectives !! and ==> are rarely required anymore in inductive goals
   337 (using object-logic connectives for this purpose has been long
   338 obsolete anyway).  The subsequent proof patterns illustrate advanced
   339 techniques of natural induction; general datatypes and inductive sets
   340 work analogously (see also src/HOL/Lambda for realistic examples).
   341 
   342 (1) This is how to ``strengthen'' an inductive goal wrt. certain
   343 parameters:
   344 
   345   lemma
   346     fixes n :: nat and x :: 'a
   347     assumes a: "A n x"
   348     shows "P n x"
   349     using a                     -- {* make induct insert fact a *}
   350   proof (induct n arbitrary: x) -- {* generalize goal to "!!x. A n x ==> P n x" *}
   351     case 0
   352     show ?case sorry
   353   next
   354     case (Suc n)
   355     note `!!x. A n x ==> P n x` -- {* induction hypothesis, according to induction rule *}
   356     note `A (Suc n) x`          -- {* induction premise, stemming from fact a *}
   357     show ?case sorry
   358   qed
   359 
   360 (2) This is how to perform induction over ``expressions of a certain
   361 form'', using a locally defined inductive parameter n == "a x"
   362 together with strengthening (the latter is usually required to get
   363 sufficiently flexible induction hypotheses):
   364 
   365   lemma
   366     fixes a :: "'a => nat"
   367     assumes a: "A (a x)"
   368     shows "P (a x)"
   369     using a
   370   proof (induct n == "a x" arbitrary: x)
   371     ...
   372 
   373 See also HOL/Isar_examples/Puzzle.thy for an application of the this
   374 particular technique.
   375 
   376 (3) This is how to perform existential reasoning ('obtains' or
   377 'obtain') by induction, while avoiding explicit object-logic
   378 encodings:
   379 
   380   lemma
   381     fixes n :: nat
   382     obtains x :: 'a where "P n x" and "Q n x"
   383   proof (induct n arbitrary: thesis)
   384     case 0
   385     obtain x where "P 0 x" and "Q 0 x" sorry
   386     then show thesis by (rule 0)
   387   next
   388     case (Suc n)
   389     obtain x where "P n x" and "Q n x" by (rule Suc.hyps)
   390     obtain x where "P (Suc n) x" and "Q (Suc n) x" sorry
   391     then show thesis by (rule Suc.prems)
   392   qed
   393 
   394 Here the 'arbitrary: thesis' specification essentially modifies the
   395 scope of the formal thesis parameter, in order to the get the whole
   396 existence statement through the induction as expected.
   397 
   398 * Provers/induct: mutual induction rules are now specified as a list
   399 of rule sharing the same induction cases.  HOL packages usually
   400 provide foo_bar.inducts for mutually defined items foo and bar
   401 (e.g. inductive sets or datatypes).  INCOMPATIBILITY, users need to
   402 specify mutual induction rules differently, i.e. like this:
   403 
   404   (induct rule: foo_bar.inducts)
   405   (induct set: foo bar)
   406   (induct type: foo bar)
   407 
   408 The ML function ProjectRule.projections turns old-style rules into the
   409 new format.
   410 
   411 * Provers/induct: improved handling of simultaneous goals.  Instead of
   412 introducing object-level conjunction, the statement is now split into
   413 several conclusions, while the corresponding symbolic cases are
   414 nested accordingly.  INCOMPATIBILITY, proofs need to be structured
   415 explicitly.  For example:
   416 
   417   lemma
   418     fixes n :: nat
   419     shows "P n" and "Q n"
   420   proof (induct n)
   421     case 0 case 1
   422     show "P 0" sorry
   423   next
   424     case 0 case 2
   425     show "Q 0" sorry
   426   next
   427     case (Suc n) case 1
   428     note `P n` and `Q n`
   429     show "P (Suc n)" sorry
   430   next
   431     case (Suc n) case 2
   432     note `P n` and `Q n`
   433     show "Q (Suc n)" sorry
   434   qed
   435 
   436 The split into subcases may be deferred as follows -- this is
   437 particularly relevant for goal statements with local premises.
   438 
   439   lemma
   440     fixes n :: nat
   441     shows "A n ==> P n" and "B n ==> Q n"
   442   proof (induct n)
   443     case 0
   444     {
   445       case 1
   446       note `A 0`
   447       show "P 0" sorry
   448     next
   449       case 2
   450       note `B 0`
   451       show "Q 0" sorry
   452     }
   453   next
   454     case (Suc n)
   455     note `A n ==> P n` and `B n ==> Q n`
   456     {
   457       case 1
   458       note `A (Suc n)`
   459       show "P (Suc n)" sorry
   460     next
   461       case 2
   462       note `B (Suc n)`
   463       show "Q (Suc n)" sorry
   464     }
   465   qed
   466 
   467 If simultaneous goals are to be used with mutual rules, the statement
   468 needs to be structured carefully as a two-level conjunction, using
   469 lists of propositions separated by 'and':
   470 
   471   lemma
   472     shows "a : A ==> P1 a"
   473           "a : A ==> P2 a"
   474       and "b : B ==> Q1 b"
   475           "b : B ==> Q2 b"
   476           "b : B ==> Q3 b"
   477   proof (induct set: A B)
   478 
   479 * Provers/induct: support coinduction as well.  See
   480 src/HOL/Library/Coinductive_List.thy for various examples.
   481 
   482 * Attribute "symmetric" produces result with standardized schematic
   483 variables (index 0).  Potential INCOMPATIBILITY.
   484 
   485 * Simplifier: by default the simplifier trace only shows top level
   486 rewrites now. That is, trace_simp_depth_limit is set to 1 by
   487 default. Thus there is less danger of being flooded by the trace. The
   488 trace indicates where parts have been suppressed.
   489   
   490 * Provers/classical: removed obsolete classical version of elim_format
   491 attribute; classical elim/dest rules are now treated uniformly when
   492 manipulating the claset.
   493 
   494 * Provers/classical: stricter checks to ensure that supplied intro,
   495 dest and elim rules are well-formed; dest and elim rules must have at
   496 least one premise.
   497 
   498 * Provers/classical: attributes dest/elim/intro take an optional
   499 weight argument for the rule (just as the Pure versions).  Weights are
   500 ignored by automated tools, but determine the search order of single
   501 rule steps.
   502 
   503 * Syntax: input syntax now supports dummy variable binding "%_. b",
   504 where the body does not mention the bound variable.  Note that dummy
   505 patterns implicitly depend on their context of bounds, which makes
   506 "{_. _}" match any set comprehension as expected.  Potential
   507 INCOMPATIBILITY -- parse translations need to cope with syntactic
   508 constant "_idtdummy" in the binding position.
   509 
   510 * Syntax: removed obsolete syntactic constant "_K" and its associated
   511 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
   512 for example "A -> B" => "Pi A (%_. B)".
   513 
   514 * Pure: 'class_deps' command visualizes the subclass relation, using
   515 the graph browser tool.
   516 
   517 * Pure: 'print_theory' now suppresses entities with internal name
   518 (trailing "_") by default; use '!' option for full details.
   519 
   520 
   521 *** HOL ***
   522 
   523 * case expressions and primrec: missing cases now mapped to "undefined"
   524 instead of "arbitrary"
   525 
   526 * new constant "undefined" with axiom "undefined x = undefined"
   527 
   528 * new class "default" with associated constant "default"
   529 
   530 * Library/Pretty_Int.thy: maps HOL numerals on target language integer literals
   531     when generating code.
   532 
   533 * Library/Pretty_Char.thy: maps HOL characters on target language character literals
   534     when generating code.
   535 
   536 * Library/Commutative_Ring.thy: switched from recdef to function package;
   537     constants add, mul, pow now curried.  Infix syntax for algebraic operations.
   538 
   539 * Some steps towards more uniform lattice theory development in HOL.
   540 
   541     constants "meet" and "join" now named "inf" and "sup"
   542     constant "Meet" now named "Inf"
   543 
   544     classes "meet_semilorder" and "join_semilorder" now named
   545       "lower_semilattice" and "upper_semilattice"
   546     class "lorder" now named "lattice"
   547     class "comp_lat" now named "complete_lattice"
   548 
   549     Instantiation of lattice classes allows explicit definitions
   550     for "inf" and "sup" operations.
   551 
   552   INCOMPATIBILITY. Theorem renames:
   553 
   554     meet_left_le            ~> inf_le1
   555     meet_right_le           ~> inf_le2
   556     join_left_le            ~> sup_ge1
   557     join_right_le           ~> sup_ge2
   558     meet_join_le            ~> inf_sup_ord
   559     le_meetI                ~> le_infI
   560     join_leI                ~> le_supI
   561     le_meet                 ~> le_inf_iff
   562     le_join                 ~> ge_sup_conv
   563     meet_idempotent         ~> inf_idem
   564     join_idempotent         ~> sup_idem
   565     meet_comm               ~> inf_commute
   566     join_comm               ~> sup_commute
   567     meet_leI1               ~> le_infI1
   568     meet_leI2               ~> le_infI2
   569     le_joinI1               ~> le_supI1
   570     le_joinI2               ~> le_supI2
   571     meet_assoc              ~> inf_assoc
   572     join_assoc              ~> sup_assoc
   573     meet_left_comm          ~> inf_left_commute
   574     meet_left_idempotent    ~> inf_left_idem
   575     join_left_comm          ~> sup_left_commute
   576     join_left_idempotent    ~> sup_left_idem
   577     meet_aci                ~> inf_aci
   578     join_aci                ~> sup_aci
   579     le_def_meet             ~> le_iff_inf
   580     le_def_join             ~> le_iff_sup
   581     join_absorp2            ~> sup_absorb2
   582     join_absorp1            ~> sup_absorb1
   583     meet_absorp1            ~> inf_absorb1
   584     meet_absorp2            ~> inf_absorb2
   585     meet_join_absorp        ~> inf_sup_absorb
   586     join_meet_absorp        ~> sup_inf_absorb
   587     distrib_join_le         ~> distrib_sup_le
   588     distrib_meet_le         ~> distrib_inf_le
   589 
   590     add_meet_distrib_left   ~> add_inf_distrib_left
   591     add_join_distrib_left   ~> add_sup_distrib_left
   592     is_join_neg_meet        ~> is_join_neg_inf
   593     is_meet_neg_join        ~> is_meet_neg_sup
   594     add_meet_distrib_right  ~> add_inf_distrib_right
   595     add_join_distrib_right  ~> add_sup_distrib_right
   596     add_meet_join_distribs  ~> add_sup_inf_distribs
   597     join_eq_neg_meet        ~> sup_eq_neg_inf
   598     meet_eq_neg_join        ~> inf_eq_neg_sup
   599     add_eq_meet_join        ~> add_eq_inf_sup
   600     meet_0_imp_0            ~> inf_0_imp_0
   601     join_0_imp_0            ~> sup_0_imp_0
   602     meet_0_eq_0             ~> inf_0_eq_0
   603     join_0_eq_0             ~> sup_0_eq_0
   604     neg_meet_eq_join        ~> neg_inf_eq_sup
   605     neg_join_eq_meet        ~> neg_sup_eq_inf
   606     join_eq_if              ~> sup_eq_if
   607 
   608     mono_meet               ~> mono_inf
   609     mono_join               ~> mono_sup
   610     meet_bool_eq            ~> inf_bool_eq
   611     join_bool_eq            ~> sup_bool_eq
   612     meet_fun_eq             ~> inf_fun_eq
   613     join_fun_eq             ~> sup_fun_eq
   614     meet_set_eq             ~> inf_set_eq
   615     join_set_eq             ~> sup_set_eq
   616     meet1_iff               ~> inf1_iff
   617     meet2_iff               ~> inf2_iff
   618     meet1I                  ~> inf1I
   619     meet2I                  ~> inf2I
   620     meet1D1                 ~> inf1D1
   621     meet2D1                 ~> inf2D1
   622     meet1D2                 ~> inf1D2
   623     meet2D2                 ~> inf2D2
   624     meet1E                  ~> inf1E
   625     meet2E                  ~> inf2E
   626     join1_iff               ~> sup1_iff
   627     join2_iff               ~> sup2_iff
   628     join1I1                 ~> sup1I1
   629     join2I1                 ~> sup2I1
   630     join1I1                 ~> sup1I1
   631     join2I2                 ~> sup1I2
   632     join1CI                 ~> sup1CI
   633     join2CI                 ~> sup2CI
   634     join1E                  ~> sup1E
   635     join2E                  ~> sup2E
   636 
   637     is_meet_Meet            ~> is_meet_Inf
   638     Meet_bool_def           ~> Inf_bool_def
   639     Meet_fun_def            ~> Inf_fun_def
   640     Meet_greatest           ~> Inf_greatest
   641     Meet_lower              ~> Inf_lower
   642     Meet_set_def            ~> Inf_set_def
   643 
   644     listsp_meetI            ~> listsp_infI
   645     listsp_meet_eq          ~> listsp_inf_eq
   646 
   647     meet_min                ~> inf_min
   648     join_max                ~> sup_max
   649 
   650 * Classes "order" and "linorder": facts "refl", "trans" and
   651 "cases" renamed ro "order_refl", "order_trans" and "linorder_cases", to
   652 avoid clashes with HOL "refl" and "trans". INCOMPATIBILITY.
   653 
   654 * Classes "order" and "linorder": 
   655 potential INCOMPATIBILITY: order of proof goals in order/linorder instance
   656 proofs changed.
   657 
   658 * Dropped lemma duplicate def_imp_eq in favor of meta_eq_to_obj_eq.
   659 INCOMPATIBILITY.
   660 
   661 * Dropped lemma duplicate if_def2 in favor of if_bool_eq_conj.
   662 INCOMPATIBILITY.
   663 
   664 * Added syntactic class "size"; overloaded constant "size" now has
   665 type "'a::size ==> bool"
   666 
   667 * Renamed constants "Divides.op div", "Divides.op mod" and "Divides.op
   668 dvd" to "Divides.div", "Divides.mod" and "Divides.dvd". INCOMPATIBILITY.
   669 
   670 * Added method "lexicographic_order" automatically synthesizes
   671 termination relations as lexicographic combinations of size measures
   672 -- 'function' package.
   673 
   674 * HOL/records: generalised field-update to take a function on the
   675 field rather than the new value: r(|A := x|) is translated to A_update
   676 (K x) r The K-combinator that is internally used is called K_record.
   677 INCOMPATIBILITY: Usage of the plain update functions has to be
   678 adapted.
   679  
   680 * axclass "semiring_0" now contains annihilation axioms x * 0 = 0 and
   681 0 * x = 0, which are required for a semiring.  Richer structures do
   682 not inherit from semiring_0 anymore, because this property is a
   683 theorem there, not an axiom.  INCOMPATIBILITY: In instances of
   684 semiring_0, there is more to prove, but this is mostly trivial.
   685 
   686 * axclass "recpower" was generalized to arbitrary monoids, not just
   687 commutative semirings.  INCOMPATIBILITY: If you use recpower and need
   688 commutativity or a semiring property, add the corresponding classes.
   689 
   690 * Unified locale partial_order with class definition (cf. theory
   691 Orderings), added parameter ``less''.  INCOMPATIBILITY.
   692 
   693 * Constant "List.list_all2" in List.thy now uses authentic syntax.
   694 INCOMPATIBILITY: translations containing list_all2 may go wrong.  On
   695 Isar level, use abbreviations instead.
   696 
   697 * Renamed constant "List.op mem" to "List.memberl" INCOMPATIBILITY:
   698 rarely occuring name references (e.g. ``List.op mem.simps'') require
   699 renaming (e.g. ``List.memberl.simps'').
   700 
   701 * Renamed constants "0" to "HOL.zero" and "1" to "HOL.one".
   702 INCOMPATIBILITY.
   703 
   704 * Added theory Code_Generator providing class 'eq', allowing for code
   705 generation with polymorphic equality.
   706 
   707 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
   708 been abandoned in favour of plain 'int'. INCOMPATIBILITY --
   709 significant changes for setting up numeral syntax for types:
   710 
   711   - new constants Numeral.pred and Numeral.succ instead
   712       of former Numeral.bin_pred and Numeral.bin_succ.
   713   - Use integer operations instead of bin_add, bin_mult and so on.
   714   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
   715   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
   716 
   717 See HOL/Integ/IntArith.thy for an example setup.
   718 
   719 * New top level command 'normal_form' computes the normal form of a
   720 term that may contain free variables. For example ``normal_form
   721 "rev[a,b,c]"'' produces ``[b,c,a]'' (without proof).  This command is
   722 suitable for heavy-duty computations because the functions are
   723 compiled to ML first.
   724 
   725 * Alternative iff syntax "A <-> B" for equality on bool (with priority
   726 25 like -->); output depends on the "iff" print_mode, the default is
   727 "A = B" (with priority 50).
   728 
   729 * Renamed constants in HOL.thy and Orderings.thy:
   730     op +   ~> HOL.plus
   731     op -   ~> HOL.minus
   732     uminus ~> HOL.uminus
   733     op *   ~> HOL.times
   734     op <   ~> Orderings.less
   735     op <=  ~> Orderings.less_eq
   736 
   737 Adaptions may be required in the following cases:
   738 
   739 a) User-defined constants using any of the names "plus", "minus", "times",
   740 "less" or "less_eq". The standard syntax translations for "+", "-" and "*"
   741 may go wrong.
   742 INCOMPATIBILITY: use more specific names.
   743 
   744 b) Variables named "plus", "minus", "times", "less", "less_eq"
   745 INCOMPATIBILITY: use more specific names.
   746 
   747 c) Permutative equations (e.g. "a + b = b + a")
   748 Since the change of names also changes the order of terms, permutative
   749 rewrite rules may get applied in a different order. Experience shows that
   750 this is rarely the case (only two adaptions in the whole Isabelle
   751 distribution).
   752 INCOMPATIBILITY: rewrite proofs
   753 
   754 d) ML code directly refering to constant names
   755 This in general only affects hand-written proof tactics, simprocs and so on.
   756 INCOMPATIBILITY: grep your sourcecode and replace names.
   757 
   758 * Relations less (<) and less_eq (<=) are also available on type bool.
   759 Modified syntax to disallow nesting without explicit parentheses,
   760 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".
   761 
   762 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
   763 
   764 * Relation composition operator "op O" now has precedence 75 and binds
   765 stronger than union and intersection. INCOMPATIBILITY.
   766 
   767 * The old set interval syntax "{m..n(}" (and relatives) has been
   768 removed.  Use "{m..<n}" (and relatives) instead.
   769 
   770 * In the context of the assumption "~(s = t)" the Simplifier rewrites
   771 "t = s" to False (by simproc "neq_simproc").  For backward
   772 compatibility this can be disabled by ML "reset use_neq_simproc".
   773 
   774 * "m dvd n" where m and n are numbers is evaluated to True/False by
   775 simp.
   776 
   777 * Theorem Cons_eq_map_conv no longer declared as ``simp''.
   778 
   779 * Theorem setsum_mult renamed to setsum_right_distrib.
   780 
   781 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
   782 ``rule'' method.
   783 
   784 * Reimplemented methods ``sat'' and ``satx'', with several
   785 improvements: goals no longer need to be stated as "<prems> ==>
   786 False", equivalences (i.e. "=" on type bool) are handled, variable
   787 names of the form "lit_<n>" are no longer reserved, significant
   788 speedup.
   789 
   790 * Methods ``sat'' and ``satx'' can now replay MiniSat proof traces.
   791 zChaff is still supported as well.
   792 
   793 * 'inductive' and 'datatype': provide projections of mutual rules,
   794 bundled as foo_bar.inducts;
   795 
   796 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
   797 Library.
   798 
   799 * Library: moved theory Accessible_Part to main HOL.
   800 
   801 * Library: added theory Coinductive_List of potentially infinite lists
   802 as greatest fixed-point.
   803 
   804 * Library: added theory AssocList which implements (finite) maps as
   805 association lists.
   806 
   807 * Added proof method ``evaluation'' for efficiently solving a goal
   808 (i.e. a boolean expression) by compiling it to ML. The goal is
   809 "proved" (via an oracle) if it evaluates to True.
   810 
   811 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
   812 also when invoked by the simplifier.  This results in the simplifier
   813 being more powerful on arithmetic goals.  INCOMPATIBILITY.  Set
   814 fast_arith_split_limit to 0 to obtain the old behavior.
   815 
   816 * Support for hex (0x20) and binary (0b1001) numerals.
   817 
   818 * New method: reify eqs (t), where eqs are equations for an
   819 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
   820 parameter, computes a term s::'b and a list xs::'a list and proves the
   821 theorem I xs s = t. This is also known as reification or quoting. The
   822 resulting theorem is applied to the subgoal to substitute t with I xs
   823 s.  If t is omitted, the subgoal itself is reified.
   824 
   825 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
   826 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
   827 where f is supposed to be a computable function (in the sense of code
   828 generattion). The method uses reify to compute s and xs as above then
   829 applies corr_thm and uses normalization by evaluation to "prove" f s =
   830 r and finally gets the theorem t = r, which is again applied to the
   831 subgoal. An Example is available in HOL/ex/ReflectionEx.thy.
   832 
   833 * Reflection: Automatic refification now handels binding, an example
   834 is available in HOL/ex/ReflectionEx.thy
   835 
   836 
   837 *** HOL-Algebra ***
   838 
   839 * Formalisation of ideals and the quotient construction over rings.
   840 
   841 * Order and lattice theory no longer based on records.
   842 INCOMPATIBILITY.
   843 
   844 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
   845 greatest_closed.  INCOMPATIBILITY.
   846 
   847 * Method algebra is now set up via an attribute.  For examples see
   848 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
   849 of algebraic structures.
   850 
   851 * Renamed theory CRing to Ring.
   852 
   853 
   854 *** HOL-Complex ***
   855 
   856 * Theory Real: new method ferrack implements quantifier elimination
   857 for linear arithmetic over the reals. The quantifier elimination
   858 feature is used only for decision, for compatibility with arith. This
   859 means a goal is either solved or left unchanged, no simplification.
   860 
   861 * Real: New axiomatic classes formalize real normed vector spaces and
   862 algebras, using new overloaded constants scaleR :: real => 'a => 'a
   863 and norm :: 'a => real.
   864 
   865 * Real: New constant of_real :: real => 'a::real_algebra_1 injects
   866 from reals into other types. The overloaded constant Reals :: 'a set
   867 is now defined as range of_real; potential INCOMPATIBILITY.
   868 
   869 * Hyperreal: Several constants that previously worked only for the
   870 reals have been generalized, so they now work over arbitrary vector
   871 spaces. Type annotations may need to be added in some cases; potential
   872 INCOMPATIBILITY.
   873 
   874   Infinitesimal  :: ('a::real_normed_vector) star set"
   875   HFinite        :: ('a::real_normed_vector) star set"
   876   HInfinite      :: ('a::real_normed_vector) star set"
   877   approx         :: ('a::real_normed_vector) star => 'a star => bool
   878   monad          :: ('a::real_normed_vector) star => 'a star set
   879   galaxy         :: ('a::real_normed_vector) star => 'a star set
   880   (NS)LIMSEQ     :: [nat, 'a::real_normed_vector, 'a] => bool
   881   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
   882   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
   883   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
   884   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
   885   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
   886   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
   887 
   888 * Complex: Some complex-specific constants are now abbreviations for
   889 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
   890 hnorm.  Other constants have been entirely removed in favor of the
   891 polymorphic versions (INCOMPATIBILITY):
   892 
   893   approx        <-- capprox
   894   HFinite       <-- CFinite
   895   HInfinite     <-- CInfinite
   896   Infinitesimal <-- CInfinitesimal
   897   monad         <-- cmonad
   898   galaxy        <-- cgalaxy
   899   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
   900   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
   901   (ns)deriv     <-- (ns)cderiv
   902 
   903 
   904 *** ML ***
   905 
   906 * Context data interfaces (Theory/Proof/GenericDataFun): removed
   907 name/print, uninitialized data defaults to ad-hoc copy of empty value,
   908 init only required for impure data.  INCOMPATIBILITY: empty really
   909 need to be empty (no dependencies on theory content!)
   910 
   911 * ML within Isar: antiquotations allow to embed statically-checked
   912 formal entities in the source, referring to the context available at
   913 compile-time.  For example:
   914 
   915 ML {* @{typ "'a => 'b"} *}
   916 ML {* @{term "%x. x"} *}
   917 ML {* @{prop "x == y"} *}
   918 ML {* @{ctyp "'a => 'b"} *}
   919 ML {* @{cterm "%x. x"} *}
   920 ML {* @{cprop "x == y"} *}
   921 ML {* @{thm asm_rl} *}
   922 ML {* @{thms asm_rl} *}
   923 ML {* @{const_name c} *}
   924 ML {* @{const_syntax c} *}
   925 ML {* @{context} *}
   926 ML {* @{theory} *}
   927 ML {* @{theory Pure} *}
   928 ML {* @{simpset} *}
   929 ML {* @{claset} *}
   930 ML {* @{clasimpset} *}
   931 
   932 The same works for sources being ``used'' within an Isar context.
   933 
   934 * ML in Isar: improved error reporting; extra verbosity with
   935 Toplevel.debug enabled.
   936 
   937 * Pure/library:
   938 
   939   val burrow: ('a list -> 'b list) -> 'a list list -> 'b list list
   940   val fold_burrow: ('a list -> 'c -> 'b list * 'd) -> 'a list list -> 'c -> 'b list list * 'd
   941 
   942 The semantics of "burrow" is: "take a function with *simulatanously*
   943 transforms a list of value, and apply it *simulatanously* to a list of
   944 list of values of the appropriate type". Compare this with "map" which
   945 would *not* apply its argument function simulatanously but in
   946 sequence; "fold_burrow" has an additional context.
   947 
   948 * Pure/library: functions map2 and fold2 with curried syntax for
   949 simultanous mapping and folding:
   950 
   951     val map2: ('a -> 'b -> 'c) -> 'a list -> 'b list -> 'c list
   952     val fold2: ('a -> 'b -> 'c -> 'c) -> 'a list -> 'b list -> 'c -> 'c
   953 
   954 * Pure/library: indexed lists - some functions in the Isabelle library
   955 treating lists over 'a as finite mappings from [0...n] to 'a have been
   956 given more convenient names and signatures reminiscent of similar
   957 functions for alists, tables, etc:
   958 
   959   val nth: 'a list -> int -> 'a 
   960   val nth_map: int -> ('a -> 'a) -> 'a list -> 'a list
   961   val fold_index: (int * 'a -> 'b -> 'b) -> 'a list -> 'b -> 'b
   962 
   963 Note that fold_index starts counting at index 0, not 1 like foldln
   964 used to.
   965 
   966 * Pure/library: added general ``divide_and_conquer'' combinator on
   967 lists.
   968 
   969 * Pure/General/table.ML: the join operations now works via exceptions
   970 DUP/SAME instead of type option.  This is simpler in simple cases, and
   971 admits slightly more efficient complex applications.
   972 
   973 * Pure: datatype Context.generic joins theory/Proof.context and
   974 provides some facilities for code that works in either kind of
   975 context, notably GenericDataFun for uniform theory and proof data.
   976 
   977 * Pure: 'advanced' translation functions (parse_translation etc.) now
   978 use Context.generic instead of just theory.
   979 
   980 * Pure: simplified internal attribute type, which is now always
   981 Context.generic * thm -> Context.generic * thm.  Global (theory)
   982 vs. local (Proof.context) attributes have been discontinued, while
   983 minimizing code duplication.  Thm.rule_attribute and
   984 Thm.declaration_attribute build canonical attributes; see also
   985 structure Context for further operations on Context.generic, notably
   986 GenericDataFun.  INCOMPATIBILITY, need to adapt attribute type
   987 declarations and definitions.
   988 
   989 * Pure/kernel: consts certification ignores sort constraints given in
   990 signature declarations.  (This information is not relevant to the
   991 logic, but only for type inference.)  IMPORTANT INTERNAL CHANGE,
   992 potential INCOMPATIBILITY.
   993 
   994 * Pure: axiomatic type classes are now purely definitional, with
   995 explicit proofs of class axioms and super class relations performed
   996 internally.  See Pure/axclass.ML for the main internal interfaces --
   997 notably AxClass.define_class supercedes AxClass.add_axclass, and
   998 AxClass.axiomatize_class/classrel/arity supercede
   999 Sign.add_classes/classrel/arities.
  1000 
  1001 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  1002 global/local versions on theory vs. Proof.context have been
  1003 discontinued; Attrib.syntax and Method.syntax have been adapted
  1004 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  1005 attributes, methods, etc.
  1006 
  1007 * Pure: several functions of signature "... -> theory -> theory * ..."
  1008 have been reoriented to "... -> theory -> ... * theory" in order to
  1009 allow natural usage in combination with the ||>, ||>>, |-> and
  1010 fold_map combinators.
  1011 
  1012 * Pure: official theorem names (closed derivations) and additional
  1013 comments (tags) are now strictly separate.  Name hints -- which are
  1014 maintained as tags -- may be attached any time without affecting the
  1015 derivation.
  1016 
  1017 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  1018 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  1019 achieve the old behaviour.
  1020 
  1021 * Pure: the "Goal" constant is now called "prop", supporting a
  1022 slightly more general idea of ``protecting'' meta-level rule
  1023 statements.
  1024 
  1025 * Pure: Logic.(un)varify only works in a global context, which is now
  1026 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  1027 Logic.legacy_(un)varify as temporary workaround.
  1028 
  1029 * Pure: structure Name provides scalable operations for generating
  1030 internal variable names, notably Name.variants etc.  This replaces
  1031 some popular functions from term.ML:
  1032 
  1033   Term.variant		->  Name.variant
  1034   Term.variantlist	->  Name.variant_list  (*canonical argument order*)
  1035   Term.invent_names	->  Name.invent_list
  1036 
  1037 Note that low-level renaming rarely occurs in new code -- operations
  1038 from structure Variable are used instead (see below).
  1039 
  1040 * Pure: structure Variable provides fundamental operations for proper
  1041 treatment of fixed/schematic variables in a context.  For example,
  1042 Variable.import introduces fixes for schematics of given facts and
  1043 Variable.export reverses the effect (up to renaming) -- this replaces
  1044 various freeze_thaw operations.
  1045 
  1046 * Pure: structure Goal provides simple interfaces for
  1047 init/conclude/finish and tactical prove operations (replacing former
  1048 Tactic.prove).  Goal.prove is the canonical way to prove results
  1049 within a given context; Goal.prove_global is a degraded version for
  1050 theory level goals, including a global Drule.standard.  Note that
  1051 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  1052 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  1053 in a locale context).
  1054 
  1055 * Isar: simplified treatment of user-level errors, using exception
  1056 ERROR of string uniformly.  Function error now merely raises ERROR,
  1057 without any side effect on output channels.  The Isar toplevel takes
  1058 care of proper display of ERROR exceptions.  ML code may use plain
  1059 handle/can/try; cat_error may be used to concatenate errors like this:
  1060 
  1061   ... handle ERROR msg => cat_error msg "..."
  1062 
  1063 Toplevel ML code (run directly or through the Isar toplevel) may be
  1064 embedded into the Isar toplevel with exception display/debug like
  1065 this:
  1066 
  1067   Isar.toplevel (fn () => ...)
  1068 
  1069 INCOMPATIBILITY, removed special transform_error facilities, removed
  1070 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  1071 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  1072 -- use plain ERROR instead.
  1073 
  1074 * Isar: theory setup now has type (theory -> theory), instead of a
  1075 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  1076 
  1077 * Isar: installed ML toplevel pretty printer for type Proof.context,
  1078 subject to ProofContext.debug/verbose flags.
  1079 
  1080 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  1081 theory before entering a proof state.  Transactions now always see a
  1082 quasi-functional intermediate checkpoint, both in interactive and
  1083 batch mode.
  1084 
  1085 * Simplifier: the simpset of a running simplification process now
  1086 contains a proof context (cf. Simplifier.the_context), which is the
  1087 very context that the initial simpset has been retrieved from (by
  1088 simpset_of/local_simpset_of).  Consequently, all plug-in components
  1089 (solver, looper etc.) may depend on arbitrary proof data.
  1090 
  1091 * Simplifier.inherit_context inherits the proof context (plus the
  1092 local bounds) of the current simplification process; any simproc
  1093 etc. that calls the Simplifier recursively should do this!  Removed
  1094 former Simplifier.inherit_bounds, which is already included here --
  1095 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  1096 specify an explicit context using Simplifier.context/theory_context.
  1097 
  1098 * Simplifier/Classical Reasoner: more abstract interfaces
  1099 change_simpset/claset for modifying the simpset/claset reference of a
  1100 theory; raw versions simpset/claset_ref etc. have been discontinued --
  1101 INCOMPATIBILITY.
  1102 
  1103 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  1104 "Trueprop" etc.
  1105 
  1106 
  1107 *** System ***
  1108 
  1109 * settings: ML_IDENTIFIER -- which is appended to user specific heap
  1110 locations -- now includes the Isabelle version identifier as well.
  1111 This simplifies use of multiple Isabelle installations.
  1112 
  1113 * isabelle-process: option -S (secure mode) disables some critical
  1114 operations, notably runtime compilation and evaluation of ML source
  1115 code.
  1116 
  1117 
  1118 New in Isabelle2005 (October 2005)
  1119 ----------------------------------
  1120 
  1121 *** General ***
  1122 
  1123 * Theory headers: the new header syntax for Isar theories is
  1124 
  1125   theory <name>
  1126   imports <theory1> ... <theoryN>
  1127   uses <file1> ... <fileM>
  1128   begin
  1129 
  1130 where the 'uses' part is optional.  The previous syntax
  1131 
  1132   theory <name> = <theory1> + ... + <theoryN>:
  1133 
  1134 will disappear in the next release.  Use isatool fixheaders to convert
  1135 existing theory files.  Note that there is no change in ancient
  1136 non-Isar theories now, but these will disappear soon.
  1137 
  1138 * Theory loader: parent theories can now also be referred to via
  1139 relative and absolute paths.
  1140 
  1141 * Command 'find_theorems' searches for a list of criteria instead of a
  1142 list of constants. Known criteria are: intro, elim, dest, name:string,
  1143 simp:term, and any term. Criteria can be preceded by '-' to select
  1144 theorems that do not match. Intro, elim, dest select theorems that
  1145 match the current goal, name:s selects theorems whose fully qualified
  1146 name contain s, and simp:term selects all simplification rules whose
  1147 lhs match term.  Any other term is interpreted as pattern and selects
  1148 all theorems matching the pattern. Available in ProofGeneral under
  1149 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  1150 
  1151   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  1152 
  1153 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  1154 matching the current goal as introduction rule and not having "HOL."
  1155 in their name (i.e. not being defined in theory HOL).
  1156 
  1157 * Command 'thms_containing' has been discontinued in favour of
  1158 'find_theorems'; INCOMPATIBILITY.
  1159 
  1160 * Communication with Proof General is now 8bit clean, which means that
  1161 Unicode text in UTF-8 encoding may be used within theory texts (both
  1162 formal and informal parts).  Cf. option -U of the Isabelle Proof
  1163 General interface.  Here are some simple examples (cf. src/HOL/ex):
  1164 
  1165   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  1166   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  1167 
  1168 * Improved efficiency of the Simplifier and, to a lesser degree, the
  1169 Classical Reasoner.  Typical big applications run around 2 times
  1170 faster.
  1171 
  1172 
  1173 *** Document preparation ***
  1174 
  1175 * Commands 'display_drafts' and 'print_drafts' perform simple output
  1176 of raw sources.  Only those symbols that do not require additional
  1177 LaTeX packages (depending on comments in isabellesym.sty) are
  1178 displayed properly, everything else is left verbatim.  isatool display
  1179 and isatool print are used as front ends (these are subject to the
  1180 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  1181 
  1182 * Command tags control specific markup of certain regions of text,
  1183 notably folding and hiding.  Predefined tags include "theory" (for
  1184 theory begin and end), "proof" for proof commands, and "ML" for
  1185 commands involving ML code; the additional tags "visible" and
  1186 "invisible" are unused by default.  Users may give explicit tag
  1187 specifications in the text, e.g. ''by %invisible (auto)''.  The
  1188 interpretation of tags is determined by the LaTeX job during document
  1189 preparation: see option -V of isatool usedir, or options -n and -t of
  1190 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  1191 \isadroptag.
  1192 
  1193 Several document versions may be produced at the same time via isatool
  1194 usedir (the generated index.html will link all of them).  Typical
  1195 specifications include ''-V document=theory,proof,ML'' to present
  1196 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  1197 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  1198 these parts without any formal replacement text.  The Isabelle site
  1199 default settings produce ''document'' and ''outline'' versions as
  1200 specified above.
  1201 
  1202 * Several new antiquotations:
  1203 
  1204   @{term_type term} prints a term with its type annotated;
  1205 
  1206   @{typeof term} prints the type of a term;
  1207 
  1208   @{const const} is the same as @{term const}, but checks that the
  1209   argument is a known logical constant;
  1210 
  1211   @{term_style style term} and @{thm_style style thm} print a term or
  1212   theorem applying a "style" to it
  1213 
  1214   @{ML text}
  1215 
  1216 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  1217 definitions, equations, inequations etc., 'concl' printing only the
  1218 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  1219 to print the specified premise.  TermStyle.add_style provides an ML
  1220 interface for introducing further styles.  See also the "LaTeX Sugar"
  1221 document practical applications.  The ML antiquotation prints
  1222 type-checked ML expressions verbatim.
  1223 
  1224 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  1225 and 'text' support optional locale specification '(in loc)', which
  1226 specifies the default context for interpreting antiquotations.  For
  1227 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  1228 
  1229 * Option 'locale=NAME' of antiquotations specifies an alternative
  1230 context interpreting the subsequent argument.  For example: @{thm
  1231 [locale=lattice] inf_assoc}.
  1232 
  1233 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  1234 a proof context.
  1235 
  1236 * Proper output of antiquotations for theory commands involving a
  1237 proof context (such as 'locale' or 'theorem (in loc) ...').
  1238 
  1239 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  1240 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  1241 
  1242 * isatool usedir: new option -C (default true) controls whether option
  1243 -D should include a copy of the original document directory; -C false
  1244 prevents unwanted effects such as copying of administrative CVS data.
  1245 
  1246 
  1247 *** Pure ***
  1248 
  1249 * Considerably improved version of 'constdefs' command.  Now performs
  1250 automatic type-inference of declared constants; additional support for
  1251 local structure declarations (cf. locales and HOL records), see also
  1252 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  1253 sequential dependencies of definitions within a single 'constdefs'
  1254 section; moreover, the declared name needs to be an identifier.  If
  1255 all fails, consider to fall back on 'consts' and 'defs' separately.
  1256 
  1257 * Improved indexed syntax and implicit structures.  First of all,
  1258 indexed syntax provides a notational device for subscripted
  1259 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  1260 expressions.  Secondly, in a local context with structure
  1261 declarations, number indexes \<^sub>n or the empty index (default
  1262 number 1) refer to a certain fixed variable implicitly; option
  1263 show_structs controls printing of implicit structures.  Typical
  1264 applications of these concepts involve record types and locales.
  1265 
  1266 * New command 'no_syntax' removes grammar declarations (and
  1267 translations) resulting from the given syntax specification, which is
  1268 interpreted in the same manner as for the 'syntax' command.
  1269 
  1270 * 'Advanced' translation functions (parse_translation etc.) may depend
  1271 on the signature of the theory context being presently used for
  1272 parsing/printing, see also isar-ref manual.
  1273 
  1274 * Improved 'oracle' command provides a type-safe interface to turn an
  1275 ML expression of type theory -> T -> term into a primitive rule of
  1276 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  1277 is already included here); see also FOL/ex/IffExample.thy;
  1278 INCOMPATIBILITY.
  1279 
  1280 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  1281 before); "cI" is no longer bound, use "c.intro" instead.
  1282 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  1283 axclasses vs. locales.
  1284 
  1285 * Improved internal renaming of symbolic identifiers -- attach primes
  1286 instead of base 26 numbers.
  1287 
  1288 * New flag show_question_marks controls printing of leading question
  1289 marks in schematic variable names.
  1290 
  1291 * In schematic variable names, *any* symbol following \<^isub> or
  1292 \<^isup> is now treated as part of the base name.  For example, the
  1293 following works without printing of awkward ".0" indexes:
  1294 
  1295   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  1296     by simp
  1297 
  1298 * Inner syntax includes (*(*nested*) comments*).
  1299 
  1300 * Pretty printer now supports unbreakable blocks, specified in mixfix
  1301 annotations as "(00...)".
  1302 
  1303 * Clear separation of logical types and nonterminals, where the latter
  1304 may only occur in 'syntax' specifications or type abbreviations.
  1305 Before that distinction was only partially implemented via type class
  1306 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  1307 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  1308 exotic syntax specifications may require further adaption
  1309 (e.g. Cube/Cube.thy).
  1310 
  1311 * Removed obsolete type class "logic", use the top sort {} instead.
  1312 Note that non-logical types should be declared as 'nonterminals'
  1313 rather than 'types'.  INCOMPATIBILITY for new object-logic
  1314 specifications.
  1315 
  1316 * Attributes 'induct' and 'cases': type or set names may now be
  1317 locally fixed variables as well.
  1318 
  1319 * Simplifier: can now control the depth to which conditional rewriting
  1320 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  1321 Limit.
  1322 
  1323 * Simplifier: simplification procedures may now take the current
  1324 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  1325 interface), which is very useful for calling the Simplifier
  1326 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  1327 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  1328 low-level mk_simproc no longer applies Logic.varify internally, to
  1329 allow for use in a context of fixed variables.
  1330 
  1331 * thin_tac now works even if the assumption being deleted contains !!
  1332 or ==>.  More generally, erule now works even if the major premise of
  1333 the elimination rule contains !! or ==>.
  1334 
  1335 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  1336 
  1337 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  1338 from Pure, which contains all common declarations already.  Both
  1339 theories are defined via plain Isabelle/Isar .thy files.
  1340 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  1341 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  1342 use isatool fixcpure to adapt your theory and ML sources.
  1343 
  1344 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  1345 selections of theorems in named facts via index ranges.
  1346 
  1347 * 'print_theorems': in theory mode, really print the difference
  1348 wrt. the last state (works for interactive theory development only),
  1349 in proof mode print all local facts (cf. 'print_facts');
  1350 
  1351 * 'hide': option '(open)' hides only base names.
  1352 
  1353 * More efficient treatment of intermediate checkpoints in interactive
  1354 theory development.
  1355 
  1356 * Code generator is now invoked via code_module (incremental code
  1357 generation) and code_library (modular code generation, ML structures
  1358 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  1359 must be quoted when used as identifiers.
  1360 
  1361 * New 'value' command for reading, evaluating and printing terms using
  1362 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  1363 quoted when used as identifier.
  1364 
  1365 
  1366 *** Locales ***
  1367 
  1368 * New commands for the interpretation of locale expressions in
  1369 theories (1), locales (2) and proof contexts (3).  These generate
  1370 proof obligations from the expression specification.  After the
  1371 obligations have been discharged, theorems of the expression are added
  1372 to the theory, target locale or proof context.  The synopsis of the
  1373 commands is a follows:
  1374 
  1375   (1) interpretation expr inst
  1376   (2) interpretation target < expr
  1377   (3) interpret expr inst
  1378 
  1379 Interpretation in theories and proof contexts require a parameter
  1380 instantiation of terms from the current context.  This is applied to
  1381 specifications and theorems of the interpreted expression.
  1382 Interpretation in locales only permits parameter renaming through the
  1383 locale expression.  Interpretation is smart in that interpretations
  1384 that are active already do not occur in proof obligations, neither are
  1385 instantiated theorems stored in duplicate.  Use 'print_interps' to
  1386 inspect active interpretations of a particular locale.  For details,
  1387 see the Isar Reference manual.  Examples can be found in
  1388 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  1389 
  1390 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  1391 'interpret' instead.
  1392 
  1393 * New context element 'constrains' for adding type constraints to
  1394 parameters.
  1395 
  1396 * Context expressions: renaming of parameters with syntax
  1397 redeclaration.
  1398 
  1399 * Locale declaration: 'includes' disallowed.
  1400 
  1401 * Proper static binding of attribute syntax -- i.e. types / terms /
  1402 facts mentioned as arguments are always those of the locale definition
  1403 context, independently of the context of later invocations.  Moreover,
  1404 locale operations (renaming and type / term instantiation) are applied
  1405 to attribute arguments as expected.
  1406 
  1407 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  1408 actual attributes; rare situations may require Attrib.attribute to
  1409 embed those attributes into Attrib.src that lack concrete syntax.
  1410 Attribute implementations need to cooperate properly with the static
  1411 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  1412 Attrib.XXX_thm etc. already do the right thing without further
  1413 intervention.  Only unusual applications -- such as "where" or "of"
  1414 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  1415 on the context and the facts involved -- may have to assign parsed
  1416 values to argument tokens explicitly.
  1417 
  1418 * Changed parameter management in theorem generation for long goal
  1419 statements with 'includes'.  INCOMPATIBILITY: produces a different
  1420 theorem statement in rare situations.
  1421 
  1422 * Locale inspection command 'print_locale' omits notes elements.  Use
  1423 'print_locale!' to have them included in the output.
  1424 
  1425 
  1426 *** Provers ***
  1427 
  1428 * Provers/hypsubst.ML: improved version of the subst method, for
  1429 single-step rewriting: it now works in bound variable contexts. New is
  1430 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  1431 rewrite a different subterm than the original subst method, which is
  1432 still available as 'simplesubst'.
  1433 
  1434 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  1435 and quasi orders.
  1436 
  1437 * Provers/trancl.ML: new transitivity reasoner for transitive and
  1438 reflexive-transitive closure of relations.
  1439 
  1440 * Provers/blast.ML: new reference depth_limit to make blast's depth
  1441 limit (previously hard-coded with a value of 20) user-definable.
  1442 
  1443 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  1444 is peformed already.  Object-logics merely need to finish their
  1445 initial simpset configuration as before.  INCOMPATIBILITY.
  1446 
  1447 
  1448 *** HOL ***
  1449 
  1450 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  1451 
  1452   syntax (epsilon)
  1453     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  1454 
  1455 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  1456 and x-symbol; use option '-m epsilon' to get it actually printed.
  1457 Moreover, the mathematically important symbolic identifier \<epsilon>
  1458 becomes available as variable, constant etc.  INCOMPATIBILITY,
  1459 
  1460 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  1461 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  1462 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  1463 support corresponding Isar calculations.
  1464 
  1465 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  1466 instead of ":".
  1467 
  1468 * theory SetInterval: changed the syntax for open intervals:
  1469 
  1470   Old       New
  1471   {..n(}    {..<n}
  1472   {)n..}    {n<..}
  1473   {m..n(}   {m..<n}
  1474   {)m..n}   {m<..n}
  1475   {)m..n(}  {m<..<n}
  1476 
  1477 The old syntax is still supported but will disappear in the next
  1478 release.  For conversion use the following Emacs search and replace
  1479 patterns (these are not perfect but work quite well):
  1480 
  1481   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  1482   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  1483 
  1484 * Theory Commutative_Ring (in Library): method comm_ring for proving
  1485 equalities in commutative rings; method 'algebra' provides a generic
  1486 interface.
  1487 
  1488 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  1489 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  1490 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  1491 be a tuple pattern.
  1492 
  1493 Some new syntax forms are available:
  1494 
  1495   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  1496   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  1497   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  1498   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  1499 
  1500 The latter form "\<Sum>x < k. e" used to be based on a separate
  1501 function "Summation", which has been discontinued.
  1502 
  1503 * theory Finite_Set: in structured induction proofs, the insert case
  1504 is now 'case (insert x F)' instead of the old counterintuitive 'case
  1505 (insert F x)'.
  1506 
  1507 * The 'refute' command has been extended to support a much larger
  1508 fragment of HOL, including axiomatic type classes, constdefs and
  1509 typedefs, inductive datatypes and recursion.
  1510 
  1511 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  1512 Requires zChaff with proof generation to be installed.  See
  1513 HOL/ex/SAT_Examples.thy for examples.
  1514 
  1515 * Datatype induction via method 'induct' now preserves the name of the
  1516 induction variable. For example, when proving P(xs::'a list) by
  1517 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  1518 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  1519 in unstructured proof scripts.
  1520 
  1521 * Reworked implementation of records.  Improved scalability for
  1522 records with many fields, avoiding performance problems for type
  1523 inference. Records are no longer composed of nested field types, but
  1524 of nested extension types. Therefore the record type only grows linear
  1525 in the number of extensions and not in the number of fields.  The
  1526 top-level (users) view on records is preserved.  Potential
  1527 INCOMPATIBILITY only in strange cases, where the theory depends on the
  1528 old record representation. The type generated for a record is called
  1529 <record_name>_ext_type.
  1530 
  1531 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  1532 proofs triggered by a record definition or a simproc (if
  1533 quick_and_dirty is enabled).  Definitions of large records can take
  1534 quite long.
  1535 
  1536 New simproc record_upd_simproc for simplification of multiple record
  1537 updates enabled by default.  Moreover, trivial updates are also
  1538 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  1539 occasionally, since simplification is more powerful by default.
  1540 
  1541 * typedef: proper support for polymorphic sets, which contain extra
  1542 type-variables in the term.
  1543 
  1544 * Simplifier: automatically reasons about transitivity chains
  1545 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  1546 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  1547 old proofs break occasionally as simplification may now solve more
  1548 goals than previously.
  1549 
  1550 * Simplifier: converts x <= y into x = y if assumption y <= x is
  1551 present.  Works for all partial orders (class "order"), in particular
  1552 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  1553 just like y <= x.
  1554 
  1555 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  1556 bound variable or a constant then the let is unfolded.  Otherwise
  1557 first a is simplified to b, and then f b is simplified to g. If
  1558 possible we abstract b from g arriving at "let x = b in h x",
  1559 otherwise we unfold the let and arrive at g.  The simproc can be
  1560 enabled/disabled by the reference use_let_simproc.  Potential
  1561 INCOMPATIBILITY since simplification is more powerful by default.
  1562 
  1563 * Classical reasoning: the meson method now accepts theorems as arguments.
  1564 
  1565 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  1566 jobs to provide advice on the provability of subgoals.
  1567 
  1568 * Theory OrderedGroup and Ring_and_Field: various additions and
  1569 improvements to faciliate calculations involving equalities and
  1570 inequalities.
  1571 
  1572 The following theorems have been eliminated or modified
  1573 (INCOMPATIBILITY):
  1574 
  1575   abs_eq             now named abs_of_nonneg
  1576   abs_of_ge_0        now named abs_of_nonneg
  1577   abs_minus_eq       now named abs_of_nonpos
  1578   imp_abs_id         now named abs_of_nonneg
  1579   imp_abs_neg_id     now named abs_of_nonpos
  1580   mult_pos           now named mult_pos_pos
  1581   mult_pos_le        now named mult_nonneg_nonneg
  1582   mult_pos_neg_le    now named mult_nonneg_nonpos
  1583   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  1584   mult_neg           now named mult_neg_neg
  1585   mult_neg_le        now named mult_nonpos_nonpos
  1586 
  1587 * Theory Parity: added rules for simplifying exponents.
  1588 
  1589 * Theory List:
  1590 
  1591 The following theorems have been eliminated or modified
  1592 (INCOMPATIBILITY):
  1593 
  1594   list_all_Nil       now named list_all.simps(1)
  1595   list_all_Cons      now named list_all.simps(2)
  1596   list_all_conv      now named list_all_iff
  1597   set_mem_eq         now named mem_iff
  1598 
  1599 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  1600 asymptotic "big O" calculations.  See the notes in BigO.thy.
  1601 
  1602 
  1603 *** HOL-Complex ***
  1604 
  1605 * Theory RealDef: better support for embedding natural numbers and
  1606 integers in the reals.
  1607 
  1608 The following theorems have been eliminated or modified
  1609 (INCOMPATIBILITY):
  1610 
  1611   exp_ge_add_one_self  now requires no hypotheses
  1612   real_of_int_add      reversed direction of equality (use [symmetric])
  1613   real_of_int_minus    reversed direction of equality (use [symmetric])
  1614   real_of_int_diff     reversed direction of equality (use [symmetric])
  1615   real_of_int_mult     reversed direction of equality (use [symmetric])
  1616 
  1617 * Theory RComplete: expanded support for floor and ceiling functions.
  1618 
  1619 * Theory Ln is new, with properties of the natural logarithm
  1620 
  1621 * Hyperreal: There is a new type constructor "star" for making
  1622 nonstandard types.  The old type names are now type synonyms:
  1623 
  1624   hypreal = real star
  1625   hypnat = nat star
  1626   hcomplex = complex star
  1627 
  1628 * Hyperreal: Many groups of similarly-defined constants have been
  1629 replaced by polymorphic versions (INCOMPATIBILITY):
  1630 
  1631   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  1632 
  1633   starset      <-- starsetNat, starsetC
  1634   *s*          <-- *sNat*, *sc*
  1635   starset_n    <-- starsetNat_n, starsetC_n
  1636   *sn*         <-- *sNatn*, *scn*
  1637   InternalSets <-- InternalNatSets, InternalCSets
  1638 
  1639   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  1640   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  1641   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  1642   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  1643   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  1644 
  1645 * Hyperreal: Many type-specific theorems have been removed in favor of
  1646 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  1647 
  1648   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  1649   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  1650   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  1651   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  1652   right_minus <-- hypreal_add_minus
  1653   left_minus <-- {hypreal,hcomplex}_add_minus_left
  1654   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  1655   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  1656   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  1657   mult_1_right <-- hcomplex_mult_one_right
  1658   mult_zero_left <-- hcomplex_mult_zero_left
  1659   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  1660   right_distrib <-- hypnat_add_mult_distrib2
  1661   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  1662   right_inverse <-- hypreal_mult_inverse
  1663   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  1664   order_refl <-- {hypreal,hypnat}_le_refl
  1665   order_trans <-- {hypreal,hypnat}_le_trans
  1666   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  1667   order_less_le <-- {hypreal,hypnat}_less_le
  1668   linorder_linear <-- {hypreal,hypnat}_le_linear
  1669   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  1670   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  1671   add_nonneg_nonneg <-- hypreal_le_add_order
  1672 
  1673 * Hyperreal: Separate theorems having to do with type-specific
  1674 versions of constants have been merged into theorems that apply to the
  1675 new polymorphic constants (INCOMPATIBILITY):
  1676 
  1677   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  1678   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  1679   STAR_Un <-- {STAR,NatStar,STARC}_Un
  1680   STAR_Int <-- {STAR,NatStar,STARC}_Int
  1681   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  1682   STAR_subset <-- {STAR,NatStar,STARC}_subset
  1683   STAR_mem <-- {STAR,NatStar,STARC}_mem
  1684   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  1685   STAR_diff <-- {STAR,STARC}_diff
  1686   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  1687     STARC_hcomplex_of_complex}_image_subset
  1688   starset_n_Un <-- starset{Nat,C}_n_Un
  1689   starset_n_Int <-- starset{Nat,C}_n_Int
  1690   starset_n_Compl <-- starset{Nat,C}_n_Compl
  1691   starset_n_diff <-- starset{Nat,C}_n_diff
  1692   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  1693   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  1694   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  1695   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  1696   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  1697   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  1698   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  1699   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  1700   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  1701   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  1702   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  1703   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  1704   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  1705   starfun_diff <-- starfun{C,RC,CR}_diff
  1706   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  1707   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  1708   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  1709   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  1710   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  1711   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  1712   starfun_Id <-- starfunC_Id
  1713   starfun_approx <-- starfun{Nat,CR}_approx
  1714   starfun_capprox <-- starfun{C,RC}_capprox
  1715   starfun_abs <-- starfunNat_rabs
  1716   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  1717   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  1718   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  1719   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  1720   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  1721   starfun_add_approx <-- starfunCR_add_approx
  1722   starfun_inverse_inverse <-- starfunC_inverse_inverse
  1723   starfun_divide <-- starfun{C,CR,RC}_divide
  1724   starfun_n <-- starfun{Nat,C}_n
  1725   starfun_n_mult <-- starfun{Nat,C}_n_mult
  1726   starfun_n_add <-- starfun{Nat,C}_n_add
  1727   starfun_n_add_minus <-- starfunNat_n_add_minus
  1728   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  1729   starfun_n_minus <-- starfun{Nat,C}_n_minus
  1730   starfun_n_eq <-- starfun{Nat,C}_n_eq
  1731 
  1732   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  1733   star_n_minus <-- {hypreal,hcomplex}_minus
  1734   star_n_diff <-- {hypreal,hcomplex}_diff
  1735   star_n_mult <-- {hypreal,hcomplex}_mult
  1736   star_n_inverse <-- {hypreal,hcomplex}_inverse
  1737   star_n_le <-- {hypreal,hypnat}_le
  1738   star_n_less <-- {hypreal,hypnat}_less
  1739   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  1740   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  1741   star_n_abs <-- hypreal_hrabs
  1742   star_n_divide <-- hcomplex_divide
  1743 
  1744   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  1745   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  1746   star_of_diff <-- hypreal_of_real_diff
  1747   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  1748   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  1749   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  1750   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  1751   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  1752   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  1753   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  1754   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  1755   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  1756   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  1757   star_of_number_of <-- {hypreal,hcomplex}_number_of
  1758   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  1759   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  1760   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  1761   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  1762   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  1763   star_of_power <-- hypreal_of_real_power
  1764   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  1765 
  1766 * Hyperreal: new method "transfer" that implements the transfer
  1767 principle of nonstandard analysis. With a subgoal that mentions
  1768 nonstandard types like "'a star", the command "apply transfer"
  1769 replaces it with an equivalent one that mentions only standard types.
  1770 To be successful, all free variables must have standard types; non-
  1771 standard variables must have explicit universal quantifiers.
  1772 
  1773 * Hyperreal: A theory of Taylor series.
  1774 
  1775 
  1776 *** HOLCF ***
  1777 
  1778 * Discontinued special version of 'constdefs' (which used to support
  1779 continuous functions) in favor of the general Pure one with full
  1780 type-inference.
  1781 
  1782 * New simplification procedure for solving continuity conditions; it
  1783 is much faster on terms with many nested lambda abstractions (cubic
  1784 instead of exponential time).
  1785 
  1786 * New syntax for domain package: selector names are now optional.
  1787 Parentheses should be omitted unless argument is lazy, for example:
  1788 
  1789   domain 'a stream = cons "'a" (lazy "'a stream")
  1790 
  1791 * New command 'fixrec' for defining recursive functions with pattern
  1792 matching; defining multiple functions with mutual recursion is also
  1793 supported.  Patterns may include the constants cpair, spair, up, sinl,
  1794 sinr, or any data constructor defined by the domain package. The given
  1795 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  1796 syntax and examples.
  1797 
  1798 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  1799 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  1800 but the proof obligation additionally includes an admissibility
  1801 requirement. The packages generate instances of class cpo or pcpo,
  1802 with continuity and strictness theorems for Rep and Abs.
  1803 
  1804 * HOLCF: Many theorems have been renamed according to a more standard naming
  1805 scheme (INCOMPATIBILITY):
  1806 
  1807   foo_inject:  "foo$x = foo$y ==> x = y"
  1808   foo_eq:      "(foo$x = foo$y) = (x = y)"
  1809   foo_less:    "(foo$x << foo$y) = (x << y)"
  1810   foo_strict:  "foo$UU = UU"
  1811   foo_defined: "... ==> foo$x ~= UU"
  1812   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  1813 
  1814 
  1815 *** ZF ***
  1816 
  1817 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  1818 including the First Isomorphism Theorem (on quotienting by the kernel
  1819 of a homomorphism).
  1820 
  1821 * ZF/Simplifier: install second copy of type solver that actually
  1822 makes use of TC rules declared to Isar proof contexts (or locales);
  1823 the old version is still required for ML proof scripts.
  1824 
  1825 
  1826 *** Cube ***
  1827 
  1828 * Converted to Isar theory format; use locales instead of axiomatic
  1829 theories.
  1830 
  1831 
  1832 *** ML ***
  1833 
  1834 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  1835 for ||>, ||>>, |>>,
  1836 
  1837 * Pure/library.ML no longer defines its own option datatype, but uses
  1838 that of the SML basis, which has constructors NONE and SOME instead of
  1839 None and Some, as well as exception Option.Option instead of OPTION.
  1840 The functions the, if_none, is_some, is_none have been adapted
  1841 accordingly, while Option.map replaces apsome.
  1842 
  1843 * Pure/library.ML: the exception LIST has been given up in favour of
  1844 the standard exceptions Empty and Subscript, as well as
  1845 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  1846 superceded by the standard hd and tl functions etc.
  1847 
  1848 A number of basic list functions are no longer exported to the ML
  1849 toplevel, as they are variants of predefined functions.  The following
  1850 suggests how one can translate existing code:
  1851 
  1852     rev_append xs ys = List.revAppend (xs, ys)
  1853     nth_elem (i, xs) = List.nth (xs, i)
  1854     last_elem xs = List.last xs
  1855     flat xss = List.concat xss
  1856     seq fs = List.app fs
  1857     partition P xs = List.partition P xs
  1858     mapfilter f xs = List.mapPartial f xs
  1859 
  1860 * Pure/library.ML: several combinators for linear functional
  1861 transformations, notably reverse application and composition:
  1862 
  1863   x |> f                f #> g
  1864   (x, y) |-> f          f #-> g
  1865 
  1866 * Pure/library.ML: introduced/changed precedence of infix operators:
  1867 
  1868   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  1869   infix 2 ?;
  1870   infix 3 o oo ooo oooo;
  1871   infix 4 ~~ upto downto;
  1872 
  1873 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  1874 infix operators.
  1875 
  1876 * Pure/library.ML: natural list combinators fold, fold_rev, and
  1877 fold_map support linear functional transformations and nesting.  For
  1878 example:
  1879 
  1880   fold f [x1, ..., xN] y =
  1881     y |> f x1 |> ... |> f xN
  1882 
  1883   (fold o fold) f [xs1, ..., xsN] y =
  1884     y |> fold f xs1 |> ... |> fold f xsN
  1885 
  1886   fold f [x1, ..., xN] =
  1887     f x1 #> ... #> f xN
  1888 
  1889   (fold o fold) f [xs1, ..., xsN] =
  1890     fold f xs1 #> ... #> fold f xsN
  1891 
  1892 * Pure/library.ML: the following selectors on type 'a option are
  1893 available:
  1894 
  1895   the:               'a option -> 'a  (*partial*)
  1896   these:             'a option -> 'a  where 'a = 'b list
  1897   the_default: 'a -> 'a option -> 'a
  1898   the_list:          'a option -> 'a list
  1899 
  1900 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  1901 basic operations for association lists, following natural argument
  1902 order; moreover the explicit equality predicate passed here avoids
  1903 potentially expensive polymorphic runtime equality checks.
  1904 The old functions may be expressed as follows:
  1905 
  1906   assoc = uncurry (AList.lookup (op =))
  1907   assocs = these oo AList.lookup (op =)
  1908   overwrite = uncurry (AList.update (op =)) o swap
  1909 
  1910 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  1911 
  1912   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  1913   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  1914 
  1915 replacing make_keylist and keyfilter (occassionally used)
  1916 Naive rewrites:
  1917 
  1918   make_keylist = AList.make
  1919   keyfilter = AList.find (op =)
  1920 
  1921 * eq_fst and eq_snd now take explicit equality parameter, thus
  1922   avoiding eqtypes. Naive rewrites:
  1923 
  1924     eq_fst = eq_fst (op =)
  1925     eq_snd = eq_snd (op =)
  1926 
  1927 * Removed deprecated apl and apr (rarely used).
  1928   Naive rewrites:
  1929 
  1930     apl (n, op) =>>= curry op n
  1931     apr (op, m) =>>= fn n => op (n, m)
  1932 
  1933 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  1934 provides a reasonably efficient light-weight implementation of sets as
  1935 lists.
  1936 
  1937 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  1938 few new operations; existing lookup and update are now curried to
  1939 follow natural argument order (for use with fold etc.);
  1940 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  1941 
  1942 * Pure/General: output via the Isabelle channels of
  1943 writeln/warning/error etc. is now passed through Output.output, with a
  1944 hook for arbitrary transformations depending on the print_mode
  1945 (cf. Output.add_mode -- the first active mode that provides a output
  1946 function wins).  Already formatted output may be embedded into further
  1947 text via Output.raw; the result of Pretty.string_of/str_of and derived
  1948 functions (string_of_term/cterm/thm etc.) is already marked raw to
  1949 accommodate easy composition of diagnostic messages etc.  Programmers
  1950 rarely need to care about Output.output or Output.raw at all, with
  1951 some notable exceptions: Output.output is required when bypassing the
  1952 standard channels (writeln etc.), or in token translations to produce
  1953 properly formatted results; Output.raw is required when capturing
  1954 already output material that will eventually be presented to the user
  1955 a second time.  For the default print mode, both Output.output and
  1956 Output.raw have no effect.
  1957 
  1958 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  1959 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  1960 cumulative results are displayed at the end of a batch session.
  1961 
  1962 * Pure/General: File.sysify_path and File.quote_sysify path have been
  1963 replaced by File.platform_path and File.shell_path (with appropriate
  1964 hooks).  This provides a clean interface for unusual systems where the
  1965 internal and external process view of file names are different.
  1966 
  1967 * Pure: more efficient orders for basic syntactic entities: added
  1968 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  1969 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  1970 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  1971 orders now -- potential INCOMPATIBILITY for code that depends on a
  1972 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  1973 Library.sort_strings on result).
  1974 
  1975 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  1976 fold_types traverse types/terms from left to right, observing natural
  1977 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  1978 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  1979 
  1980 * Pure: name spaces have been refined, with significant changes of the
  1981 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  1982 to extern(_table).  The plain name entry path is superceded by a
  1983 general 'naming' context, which also includes the 'policy' to produce
  1984 a fully qualified name and external accesses of a fully qualified
  1985 name; NameSpace.extend is superceded by context dependent
  1986 Sign.declare_name.  Several theory and proof context operations modify
  1987 the naming context.  Especially note Theory.restore_naming and
  1988 ProofContext.restore_naming to get back to a sane state; note that
  1989 Theory.add_path is no longer sufficient to recover from
  1990 Theory.absolute_path in particular.
  1991 
  1992 * Pure: new flags short_names (default false) and unique_names
  1993 (default true) for controlling output of qualified names.  If
  1994 short_names is set, names are printed unqualified.  If unique_names is
  1995 reset, the name prefix is reduced to the minimum required to achieve
  1996 the original result when interning again, even if there is an overlap
  1997 with earlier declarations.
  1998 
  1999 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  2000 now 'extend', and 'merge' gets an additional Pretty.pp argument
  2001 (useful for printing error messages).  INCOMPATIBILITY.
  2002 
  2003 * Pure: major reorganization of the theory context.  Type Sign.sg and
  2004 Theory.theory are now identified, referring to the universal
  2005 Context.theory (see Pure/context.ML).  Actual signature and theory
  2006 content is managed as theory data.  The old code and interfaces were
  2007 spread over many files and structures; the new arrangement introduces
  2008 considerable INCOMPATIBILITY to gain more clarity:
  2009 
  2010   Context -- theory management operations (name, identity, inclusion,
  2011     parents, ancestors, merge, etc.), plus generic theory data;
  2012 
  2013   Sign -- logical signature and syntax operations (declaring consts,
  2014     types, etc.), plus certify/read for common entities;
  2015 
  2016   Theory -- logical theory operations (stating axioms, definitions,
  2017     oracles), plus a copy of logical signature operations (consts,
  2018     types, etc.); also a few basic management operations (Theory.copy,
  2019     Theory.merge, etc.)
  2020 
  2021 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  2022 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  2023 for convenience -- they merely return the theory.
  2024 
  2025 * Pure: type Type.tsig is superceded by theory in most interfaces.
  2026 
  2027 * Pure: the Isar proof context type is already defined early in Pure
  2028 as Context.proof (note that ProofContext.context and Proof.context are
  2029 aliases, where the latter is the preferred name).  This enables other
  2030 Isabelle components to refer to that type even before Isar is present.
  2031 
  2032 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  2033 typeK, constK, axiomK, oracleK), but provide explicit operations for
  2034 any of these kinds.  For example, Sign.intern typeK is now
  2035 Sign.intern_type, Theory.hide_space Sign.typeK is now
  2036 Theory.hide_types.  Also note that former
  2037 Theory.hide_classes/types/consts are now
  2038 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  2039 internalize their arguments!  INCOMPATIBILITY.
  2040 
  2041 * Pure: get_thm interface (of PureThy and ProofContext) expects
  2042 datatype thmref (with constructors Name and NameSelection) instead of
  2043 plain string -- INCOMPATIBILITY;
  2044 
  2045 * Pure: cases produced by proof methods specify options, where NONE
  2046 means to remove case bindings -- INCOMPATIBILITY in
  2047 (RAW_)METHOD_CASES.
  2048 
  2049 * Pure: the following operations retrieve axioms or theorems from a
  2050 theory node or theory hierarchy, respectively:
  2051 
  2052   Theory.axioms_of: theory -> (string * term) list
  2053   Theory.all_axioms_of: theory -> (string * term) list
  2054   PureThy.thms_of: theory -> (string * thm) list
  2055   PureThy.all_thms_of: theory -> (string * thm) list
  2056 
  2057 * Pure: print_tac now outputs the goal through the trace channel.
  2058 
  2059 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  2060 Reference Toplevel.debug (default false) controls detailed printing
  2061 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  2062 controls execution profiling -- set to 1 for time and 2 for space
  2063 (both increase the runtime).
  2064 
  2065 * Isar session: The initial use of ROOT.ML is now always timed,
  2066 i.e. the log will show the actual process times, in contrast to the
  2067 elapsed wall-clock time that the outer shell wrapper produces.
  2068 
  2069 * Simplifier: improved handling of bound variables (nameless
  2070 representation, avoid allocating new strings).  Simprocs that invoke
  2071 the Simplifier recursively should use Simplifier.inherit_bounds to
  2072 avoid local name clashes.  Failure to do so produces warnings
  2073 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  2074 for further details.
  2075 
  2076 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  2077 bindings for all theorems stored within a given theory; this may help
  2078 in porting non-Isar theories to Isar ones, while keeping ML proof
  2079 scripts for the time being.
  2080 
  2081 * ML operator HTML.with_charset specifies the charset begin used for
  2082 generated HTML files.  For example:
  2083 
  2084   HTML.with_charset "utf-8" use_thy "Hebrew";
  2085   HTML.with_charset "utf-8" use_thy "Chinese";
  2086 
  2087 
  2088 *** System ***
  2089 
  2090 * Allow symlinks to all proper Isabelle executables (Isabelle,
  2091 isabelle, isatool etc.).
  2092 
  2093 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  2094 isatool doc, isatool mkdir, display_drafts etc.).
  2095 
  2096 * isatool usedir: option -f allows specification of the ML file to be
  2097 used by Isabelle; default is ROOT.ML.
  2098 
  2099 * New isatool version outputs the version identifier of the Isabelle
  2100 distribution being used.
  2101 
  2102 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  2103 (containing Boolean satisfiability problems) into Isabelle/HOL
  2104 theories.
  2105 
  2106 
  2107 
  2108 New in Isabelle2004 (April 2004)
  2109 --------------------------------
  2110 
  2111 *** General ***
  2112 
  2113 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  2114   Replaces linorder.ML.
  2115 
  2116 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  2117   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  2118   (\<a>...\<z>), are now considered normal letters, and can therefore
  2119   be used anywhere where an ASCII letter (a...zA...Z) has until
  2120   now. COMPATIBILITY: This obviously changes the parsing of some
  2121   terms, especially where a symbol has been used as a binder, say
  2122   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  2123   as an identifier.  Fix it by inserting a space around former
  2124   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  2125   existing theory and ML files.
  2126 
  2127 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  2128 
  2129 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  2130   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  2131   a normal (but invisible) letter. For multiple letter subscripts repeat
  2132   \<^isub> like this: x\<^isub>1\<^isub>2.
  2133 
  2134 * Pure: There are now sub-/superscripts that can span more than one
  2135   character. Text between \<^bsub> and \<^esub> is set in subscript in
  2136   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  2137   superscript. The new control characters are not identifier parts.
  2138 
  2139 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  2140   content of "..." to the latex file instead of \isacntrl... . The "..."
  2141   may consist of any printable characters excluding the end bracket >.
  2142 
  2143 * Pure: Using new Isar command "finalconsts" (or the ML functions
  2144   Theory.add_finals or Theory.add_finals_i) it is now possible to
  2145   declare constants "final", which prevents their being given a definition
  2146   later.  It is useful for constants whose behaviour is fixed axiomatically
  2147   rather than definitionally, such as the meta-logic connectives.
  2148 
  2149 * Pure: 'instance' now handles general arities with general sorts
  2150   (i.e. intersections of classes),
  2151 
  2152 * Presentation: generated HTML now uses a CSS style sheet to make layout
  2153   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  2154   It can be changed to alter the colors/layout of generated pages.
  2155 
  2156 
  2157 *** Isar ***
  2158 
  2159 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  2160   cut_tac, subgoal_tac and thin_tac:
  2161   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  2162     locales are no longer forced to write Isar proof scripts.
  2163     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  2164     emulations.
  2165   - INCOMPATIBILITY: names of variables to be instantiated may no
  2166     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  2167     This is consistent with the instantiation attribute "where".
  2168 
  2169 * Attributes "where" and "of":
  2170   - Now take type variables of instantiated theorem into account when reading
  2171     the instantiation string.  This fixes a bug that caused instantiated
  2172     theorems to have too special types in some circumstances.
  2173   - "where" permits explicit instantiations of type variables.
  2174 
  2175 * Calculation commands "moreover" and "also" no longer interfere with
  2176   current facts ("this"), admitting arbitrary combinations with "then"
  2177   and derived forms.
  2178 
  2179 * Locales:
  2180   - Goal statements involving the context element "includes" no longer
  2181     generate theorems with internal delta predicates (those ending on
  2182     "_axioms") in the premise.
  2183     Resolve particular premise with <locale>.intro to obtain old form.
  2184   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  2185     specification and "includes" elements in goal statement.
  2186   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  2187     [intro?] and [elim?] (respectively) by default.
  2188   - Experimental command for instantiation of locales in proof contexts:
  2189         instantiate <label>[<attrs>]: <loc>
  2190     Instantiates locale <loc> and adds all its theorems to the current context
  2191     taking into account their attributes.  Label and attrs are optional
  2192     modifiers, like in theorem declarations.  If present, names of
  2193     instantiated theorems are qualified with <label>, and the attributes
  2194     <attrs> are applied after any attributes these theorems might have already.
  2195       If the locale has assumptions, a chained fact of the form
  2196     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  2197     are derived.  The command does not support old-style locales declared
  2198     with "locale (open)".
  2199       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  2200 
  2201 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  2202   (Isar) contexts.
  2203 
  2204 
  2205 *** HOL ***
  2206 
  2207 * Proof import: new image HOL4 contains the imported library from
  2208   the HOL4 system with about 2500 theorems. It is imported by
  2209   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  2210   can be used like any other Isabelle image.  See
  2211   HOL/Import/HOL/README for more information.
  2212 
  2213 * Simplifier:
  2214   - Much improved handling of linear and partial orders.
  2215     Reasoners for linear and partial orders are set up for type classes
  2216     "linorder" and "order" respectively, and are added to the default simpset
  2217     as solvers.  This means that the simplifier can build transitivity chains
  2218     to solve goals from the assumptions.
  2219   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  2220     of blast or auto after simplification become unnecessary because the goal
  2221     is solved by simplification already.
  2222 
  2223 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  2224     all proved in axiomatic type classes for semirings, rings and fields.
  2225 
  2226 * Numerics:
  2227   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  2228     now formalized using the Ring_and_Field theory mentioned above.
  2229   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  2230     than before, because now they are set up once in a generic manner.
  2231   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  2232     Look for the general versions in Ring_and_Field (and Power if they concern
  2233     exponentiation).
  2234 
  2235 * Type "rat" of the rational numbers is now available in HOL-Complex.
  2236 
  2237 * Records:
  2238   - Record types are now by default printed with their type abbreviation
  2239     instead of the list of all field types. This can be configured via
  2240     the reference "print_record_type_abbr".
  2241   - Simproc "record_upd_simproc" for simplification of multiple updates added
  2242     (not enabled by default).
  2243   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  2244     EX x. x = sel r to True (not enabled by default).
  2245   - Tactic "record_split_simp_tac" to split and simplify records added.
  2246 
  2247 * 'specification' command added, allowing for definition by
  2248   specification.  There is also an 'ax_specification' command that
  2249   introduces the new constants axiomatically.
  2250 
  2251 * arith(_tac) is now able to generate counterexamples for reals as well.
  2252 
  2253 * HOL-Algebra: new locale "ring" for non-commutative rings.
  2254 
  2255 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  2256   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  2257 
  2258 * HOL-Matrix: a first theory for matrices in HOL with an application of
  2259   matrix theory to linear programming.
  2260 
  2261 * Unions and Intersections:
  2262   The latex output syntax of UN and INT has been changed
  2263   from "\Union x \in A. B" to "\Union_{x \in A} B"
  2264   i.e. the index formulae has become a subscript.
  2265   Similarly for "\Union x. B", and for \Inter instead of \Union.
  2266 
  2267 * Unions and Intersections over Intervals:
  2268   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  2269   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  2270   like in normal math, and corresponding versions for < and for intersection.
  2271 
  2272 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  2273   lexicographic dictonary ordering has been added as "lexord".
  2274 
  2275 * ML: the legacy theory structures Int and List have been removed. They had
  2276   conflicted with ML Basis Library structures having the same names.
  2277 
  2278 * 'refute' command added to search for (finite) countermodels.  Only works
  2279   for a fragment of HOL.  The installation of an external SAT solver is
  2280   highly recommended.  See "HOL/Refute.thy" for details.
  2281 
  2282 * 'quickcheck' command: Allows to find counterexamples by evaluating
  2283   formulae under an assignment of free variables to random values.
  2284   In contrast to 'refute', it can deal with inductive datatypes,
  2285   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  2286   for examples.
  2287 
  2288 
  2289 *** HOLCF ***
  2290 
  2291 * Streams now come with concatenation and are part of the HOLCF image
  2292 
  2293 
  2294 
  2295 New in Isabelle2003 (May 2003)
  2296 ------------------------------
  2297 
  2298 *** General ***
  2299 
  2300 * Provers/simplifier:
  2301 
  2302   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  2303     Assumptions are now subject to complete mutual simplification,
  2304     not just from left to right. The simplifier now preserves
  2305     the order of assumptions.
  2306 
  2307     Potential INCOMPATIBILITY:
  2308 
  2309     -- simp sometimes diverges where the old version did
  2310        not, e.g. invoking simp on the goal
  2311 
  2312         [| P (f x); y = x; f x = f y |] ==> Q
  2313 
  2314        now gives rise to the infinite reduction sequence
  2315 
  2316         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  2317 
  2318        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  2319        kind of problem.
  2320 
  2321     -- Tactics combining classical reasoner and simplification (such as auto)
  2322        are also affected by this change, because many of them rely on
  2323        simp. They may sometimes diverge as well or yield a different numbers
  2324        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  2325        in case of problems. Sometimes subsequent calls to the classical
  2326        reasoner will fail because a preceeding call to the simplifier too
  2327        eagerly simplified the goal, e.g. deleted redundant premises.
  2328 
  2329   - The simplifier trace now shows the names of the applied rewrite rules
  2330 
  2331   - You can limit the number of recursive invocations of the simplifier
  2332     during conditional rewriting (where the simplifie tries to solve the
  2333     conditions before applying the rewrite rule):
  2334     ML "simp_depth_limit := n"
  2335     where n is an integer. Thus you can force termination where previously
  2336     the simplifier would diverge.
  2337 
  2338   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  2339 
  2340   - No longer aborts on failed congruence proof.  Instead, the
  2341     congruence is ignored.
  2342 
  2343 * Pure: New generic framework for extracting programs from constructive
  2344   proofs. See HOL/Extraction.thy for an example instantiation, as well
  2345   as HOL/Extraction for some case studies.
  2346 
  2347 * Pure: The main goal of the proof state is no longer shown by default, only
  2348 the subgoals. This behaviour is controlled by a new flag.
  2349    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  2350 (ML: Proof.show_main_goal).
  2351 
  2352 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  2353 rules whose conclusion matches subgoal 1:
  2354       PG menu: Isabelle/Isar -> Show me -> matching rules
  2355 The rules are ordered by how closely they match the subgoal.
  2356 In particular, rules that solve a subgoal outright are displayed first
  2357 (or rather last, the way they are printed).
  2358 (ML: ProofGeneral.print_intros())
  2359 
  2360 * Pure: New flag trace_unify_fail causes unification to print
  2361 diagnostic information (PG: in trace buffer) when it fails. This is
  2362 useful for figuring out why single step proofs like rule, erule or
  2363 assumption failed.
  2364 
  2365 * Pure: Locale specifications now produce predicate definitions
  2366 according to the body of text (covering assumptions modulo local
  2367 definitions); predicate "loc_axioms" covers newly introduced text,
  2368 while "loc" is cumulative wrt. all included locale expressions; the
  2369 latter view is presented only on export into the global theory
  2370 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  2371 on the old view without predicates;
  2372 
  2373 * Pure: predefined locales "var" and "struct" are useful for sharing
  2374 parameters (as in CASL, for example); just specify something like
  2375 ``var x + var y + struct M'' as import;
  2376 
  2377 * Pure: improved thms_containing: proper indexing of facts instead of
  2378 raw theorems; check validity of results wrt. current name space;
  2379 include local facts of proof configuration (also covers active
  2380 locales), cover fixed variables in index; may use "_" in term
  2381 specification; an optional limit for the number of printed facts may
  2382 be given (the default is 40);
  2383 
  2384 * Pure: disallow duplicate fact bindings within new-style theory files
  2385 (batch-mode only);
  2386 
  2387 * Provers: improved induct method: assumptions introduced by case
  2388 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  2389 the goal statement); "foo" still refers to all facts collectively;
  2390 
  2391 * Provers: the function blast.overloaded has been removed: all constants
  2392 are regarded as potentially overloaded, which improves robustness in exchange
  2393 for slight decrease in efficiency;
  2394 
  2395 * Provers/linorder: New generic prover for transitivity reasoning over
  2396 linear orders.  Note: this prover is not efficient!
  2397 
  2398 * Isar: preview of problems to finish 'show' now produce an error
  2399 rather than just a warning (in interactive mode);
  2400 
  2401 
  2402 *** HOL ***
  2403 
  2404 * arith(_tac)
  2405 
  2406  - Produces a counter example if it cannot prove a goal.
  2407    Note that the counter example may be spurious if the goal is not a formula
  2408    of quantifier-free linear arithmetic.
  2409    In ProofGeneral the counter example appears in the trace buffer.
  2410 
  2411  - Knows about div k and mod k where k is a numeral of type nat or int.
  2412 
  2413  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  2414    linear arithmetic fails. This takes account of quantifiers and divisibility.
  2415    Presburger arithmetic can also be called explicitly via presburger(_tac).
  2416 
  2417 * simp's arithmetic capabilities have been enhanced a bit: it now
  2418 takes ~= in premises into account (by performing a case split);
  2419 
  2420 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  2421 are distributed over a sum of terms;
  2422 
  2423 * New tactic "trans_tac" and method "trans" instantiate
  2424 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  2425 "<=", "<" and "=").
  2426 
  2427 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  2428 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  2429 
  2430 * 'typedef' command has new option "open" to suppress the set
  2431 definition;
  2432 
  2433 * functions Min and Max on finite sets have been introduced (theory
  2434 Finite_Set);
  2435 
  2436 * attribute [symmetric] now works for relations as well; it turns
  2437 (x,y) : R^-1 into (y,x) : R, and vice versa;
  2438 
  2439 * induct over a !!-quantified statement (say !!x1..xn):
  2440   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  2441 
  2442 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  2443 %x. None. Warning: empty_def now refers to the previously hidden definition
  2444 of the empty set.
  2445 
  2446 * Algebra: formalization of classical algebra.  Intended as base for
  2447 any algebraic development in Isabelle.  Currently covers group theory
  2448 (up to Sylow's theorem) and ring theory (Universal Property of
  2449 Univariate Polynomials).  Contributions welcome;
  2450 
  2451 * GroupTheory: deleted, since its material has been moved to Algebra;
  2452 
  2453 * Complex: new directory of the complex numbers with numeric constants,
  2454 nonstandard complex numbers, and some complex analysis, standard and
  2455 nonstandard (Jacques Fleuriot);
  2456 
  2457 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  2458 
  2459 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  2460 Fleuriot);
  2461 
  2462 * Real/HahnBanach: updated and adapted to locales;
  2463 
  2464 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  2465 Gray and Kramer);
  2466 
  2467 * UNITY: added the Meier-Sanders theory of progress sets;
  2468 
  2469 * MicroJava: bytecode verifier and lightweight bytecode verifier
  2470 as abstract algorithms, instantiated to the JVM;
  2471 
  2472 * Bali: Java source language formalization. Type system, operational
  2473 semantics, axiomatic semantics. Supported language features:
  2474 classes, interfaces, objects,virtual methods, static methods,
  2475 static/instance fields, arrays, access modifiers, definite
  2476 assignment, exceptions.
  2477 
  2478 
  2479 *** ZF ***
  2480 
  2481 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  2482 universe, etc.);
  2483 
  2484 * Main ZF: virtually all theories converted to new-style format;
  2485 
  2486 
  2487 *** ML ***
  2488 
  2489 * Pure: Tactic.prove provides sane interface for internal proofs;
  2490 omits the infamous "standard" operation, so this is more appropriate
  2491 than prove_goalw_cterm in many situations (e.g. in simprocs);
  2492 
  2493 * Pure: improved error reporting of simprocs;
  2494 
  2495 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  2496 up simprocs;
  2497 
  2498 
  2499 *** Document preparation ***
  2500 
  2501 * uses \par instead of \\ for line breaks in theory text. This may
  2502 shift some page breaks in large documents. To get the old behaviour
  2503 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  2504 
  2505 * minimized dependencies of isabelle.sty and isabellesym.sty on
  2506 other packages
  2507 
  2508 * \<euro> now needs package babel/greek instead of marvosym (which
  2509 broke \Rightarrow)
  2510 
  2511 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  2512 textcomp package)
  2513 
  2514 
  2515 
  2516 New in Isabelle2002 (March 2002)
  2517 --------------------------------
  2518 
  2519 *** Document preparation ***
  2520 
  2521 * greatly simplified document preparation setup, including more
  2522 graceful interpretation of isatool usedir -i/-d/-D options, and more
  2523 instructive isatool mkdir; users should basically be able to get
  2524 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  2525 users may run a separate document processing stage manually like this:
  2526 "isatool usedir -D output HOL Test && isatool document Test/output";
  2527 
  2528 * theory dependency graph may now be incorporated into documents;
  2529 isatool usedir -g true will produce session_graph.eps/.pdf for use
  2530 with \includegraphics of LaTeX;
  2531 
  2532 * proper spacing of consecutive markup elements, especially text
  2533 blocks after section headings;
  2534 
  2535 * support bold style (for single symbols only), input syntax is like
  2536 this: "\<^bold>\<alpha>" or "\<^bold>A";
  2537 
  2538 * \<bullet> is now output as bold \cdot by default, which looks much
  2539 better in printed text;
  2540 
  2541 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  2542 note that these symbols are currently unavailable in Proof General /
  2543 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  2544 
  2545 * isatool latex no longer depends on changed TEXINPUTS, instead
  2546 isatool document copies the Isabelle style files to the target
  2547 location;
  2548 
  2549 
  2550 *** Isar ***
  2551 
  2552 * Pure/Provers: improved proof by cases and induction;
  2553   - 'case' command admits impromptu naming of parameters (such as
  2554     "case (Suc n)");
  2555   - 'induct' method divinates rule instantiation from the inductive
  2556     claim; no longer requires excessive ?P bindings for proper
  2557     instantiation of cases;
  2558   - 'induct' method properly enumerates all possibilities of set/type
  2559     rules; as a consequence facts may be also passed through *type*
  2560     rules without further ado;
  2561   - 'induct' method now derives symbolic cases from the *rulified*
  2562     rule (before it used to rulify cases stemming from the internal
  2563     atomized version); this means that the context of a non-atomic
  2564     statement becomes is included in the hypothesis, avoiding the
  2565     slightly cumbersome show "PROP ?case" form;
  2566   - 'induct' may now use elim-style induction rules without chaining
  2567     facts, using ``missing'' premises from the goal state; this allows
  2568     rules stemming from inductive sets to be applied in unstructured
  2569     scripts, while still benefitting from proper handling of non-atomic
  2570     statements; NB: major inductive premises need to be put first, all
  2571     the rest of the goal is passed through the induction;
  2572   - 'induct' proper support for mutual induction involving non-atomic
  2573     rule statements (uses the new concept of simultaneous goals, see
  2574     below);
  2575   - append all possible rule selections, but only use the first
  2576     success (no backtracking);
  2577   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  2578   - undeclared rule case names default to numbers 1, 2, 3, ...;
  2579   - added 'print_induct_rules' (covered by help item in recent Proof
  2580     General versions);
  2581   - moved induct/cases attributes to Pure, methods to Provers;
  2582   - generic method setup instantiated for FOL and HOL;
  2583 
  2584 * Pure: support multiple simultaneous goal statements, for example
  2585 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  2586 meta-level mechanism, this acts as if several individual goals had
  2587 been stated separately; in particular common proof methods need to be
  2588 repeated in order to cover all claims; note that a single elimination
  2589 step is *not* sufficient to establish the two conjunctions, so this
  2590 fails:
  2591 
  2592   assume "A & B" then have A and B ..   (*".." fails*)
  2593 
  2594 better use "obtain" in situations as above; alternative refer to
  2595 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  2596 
  2597 * Pure: proper integration with ``locales''; unlike the original
  2598 version by Florian Kammller, Isar locales package high-level proof
  2599 contexts rather than raw logical ones (e.g. we admit to include
  2600 attributes everywhere); operations on locales include merge and
  2601 rename; support for implicit arguments (``structures''); simultaneous
  2602 type-inference over imports and text; see also HOL/ex/Locales.thy for
  2603 some examples;
  2604 
  2605 * Pure: the following commands have been ``localized'', supporting a
  2606 target locale specification "(in name)": 'lemma', 'theorem',
  2607 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  2608 stored both within the locale and at the theory level (exported and
  2609 qualified by the locale name);
  2610 
  2611 * Pure: theory goals may now be specified in ``long'' form, with
  2612 ad-hoc contexts consisting of arbitrary locale elements. for example
  2613 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  2614 definitions may be given, too); the result is a meta-level rule with
  2615 the context elements being discharged in the obvious way;
  2616 
  2617 * Pure: new proof command 'using' allows to augment currently used
  2618 facts after a goal statement ('using' is syntactically analogous to
  2619 'apply', but acts on the goal's facts only); this allows chained facts
  2620 to be separated into parts given before and after a claim, as in
  2621 ``from a and b have C using d and e <proof>'';
  2622 
  2623 * Pure: renamed "antecedent" case to "rule_context";
  2624 
  2625 * Pure: new 'judgment' command records explicit information about the
  2626 object-logic embedding (used by several tools internally); no longer
  2627 use hard-wired "Trueprop";
  2628 
  2629 * Pure: added 'corollary' command;
  2630 
  2631 * Pure: fixed 'token_translation' command;
  2632 
  2633 * Pure: removed obsolete 'exported' attribute;
  2634 
  2635 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  2636 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  2637 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  2638 
  2639 * Pure: method 'atomize' presents local goal premises as object-level
  2640 statements (atomic meta-level propositions); setup controlled via
  2641 rewrite rules declarations of 'atomize' attribute; example
  2642 application: 'induct' method with proper rule statements in improper
  2643 proof *scripts*;
  2644 
  2645 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  2646 now consider the syntactic context of assumptions, giving a better
  2647 chance to get type-inference of the arguments right (this is
  2648 especially important for locales);
  2649 
  2650 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  2651 mode;
  2652 
  2653 * Pure/obtain: the formal conclusion "thesis", being marked as
  2654 ``internal'', may no longer be reference directly in the text;
  2655 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  2656 situations;
  2657 
  2658 * Pure: generic 'sym' attribute which declares a rule both as pure
  2659 'elim?' and for the 'symmetric' operation;
  2660 
  2661 * Pure: marginal comments ``--'' may now occur just anywhere in the
  2662 text; the fixed correlation with particular command syntax has been
  2663 discontinued;
  2664 
  2665 * Pure: new method 'rules' is particularly well-suited for proof
  2666 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  2667 but often produces more compact proof terms with less detours;
  2668 
  2669 * Pure/Provers/classical: simplified integration with pure rule
  2670 attributes and methods; the classical "intro?/elim?/dest?"
  2671 declarations coincide with the pure ones; the "rule" method no longer
  2672 includes classically swapped intros; "intro" and "elim" methods no
  2673 longer pick rules from the context; also got rid of ML declarations
  2674 AddXIs/AddXEs/AddXDs; all of this has some potential for
  2675 INCOMPATIBILITY;
  2676 
  2677 * Provers/classical: attribute 'swapped' produces classical inversions
  2678 of introduction rules;
  2679 
  2680 * Provers/simplifier: 'simplified' attribute may refer to explicit
  2681 rules instead of full simplifier context; 'iff' attribute handles
  2682 conditional rules;
  2683 
  2684 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  2685 
  2686 * HOL: 'recdef' now fails on unfinished automated proofs, use
  2687 "(permissive)" option to recover old behavior;
  2688 
  2689 * HOL: 'inductive' no longer features separate (collective) attributes
  2690 for 'intros' (was found too confusing);
  2691 
  2692 * HOL: properly declared induction rules less_induct and
  2693 wf_induct_rule;
  2694 
  2695 
  2696 *** HOL ***
  2697 
  2698 * HOL: moved over to sane numeral syntax; the new policy is as
  2699 follows:
  2700 
  2701   - 0 and 1 are polymorphic constants, which are defined on any
  2702   numeric type (nat, int, real etc.);
  2703 
  2704   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  2705   binary representation internally;
  2706 
  2707   - type nat has special constructor Suc, and generally prefers Suc 0
  2708   over 1::nat and Suc (Suc 0) over 2::nat;
  2709 
  2710 This change may cause significant problems of INCOMPATIBILITY; here
  2711 are some hints on converting existing sources:
  2712 
  2713   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  2714   entities, so expressions involving "-" (unary or binary minus) need
  2715   to be spaced properly;
  2716 
  2717   - existing occurrences of "1" may need to be constraint "1::nat" or
  2718   even replaced by Suc 0; similar for old "2";
  2719 
  2720   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  2721 
  2722   - remove all special provisions on numerals in proofs;
  2723 
  2724 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  2725 representation (depends on bin_arith_simps in the default context);
  2726 
  2727 * HOL: symbolic syntax for x^2 (numeral 2);
  2728 
  2729 * HOL: the class of all HOL types is now called "type" rather than
  2730 "term"; INCOMPATIBILITY, need to adapt references to this type class
  2731 in axclass/classes, instance/arities, and (usually rare) occurrences
  2732 in typings (of consts etc.); internally the class is called
  2733 "HOL.type", ML programs should refer to HOLogic.typeS;
  2734 
  2735 * HOL/record package improvements:
  2736   - new derived operations "fields" to build a partial record section,
  2737     "extend" to promote a fixed record to a record scheme, and
  2738     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  2739     declared as simp by default;
  2740   - shared operations ("more", "fields", etc.) now need to be always
  2741     qualified) --- potential INCOMPATIBILITY;
  2742   - removed "make_scheme" operations (use "make" with "extend") --
  2743     INCOMPATIBILITY;
  2744   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  2745   - provides cases/induct rules for use with corresponding Isar
  2746     methods (for concrete records, record schemes, concrete more
  2747     parts, and schematic more parts -- in that order);
  2748   - internal definitions directly based on a light-weight abstract
  2749     theory of product types over typedef rather than datatype;
  2750 
  2751 * HOL: generic code generator for generating executable ML code from
  2752 specifications; specific support for HOL constructs such as inductive
  2753 datatypes and sets, as well as recursive functions; can be invoked
  2754 via 'generate_code' theory section;
  2755 
  2756 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  2757 
  2758 * HOL: consolidated and renamed several theories.  In particular:
  2759         Ord.thy has been absorbed into HOL.thy
  2760         String.thy has been absorbed into List.thy
  2761 
  2762 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  2763 (beware of argument permutation!);
  2764 
  2765 * HOL: linorder_less_split superseded by linorder_cases;
  2766 
  2767 * HOL/List: "nodups" renamed to "distinct";
  2768 
  2769 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  2770 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  2771   - Ex_def has changed, now need to use some_eq_ex
  2772 
  2773 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  2774 in this (rare) case use:
  2775 
  2776   delSWrapper "split_all_tac"
  2777   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  2778 
  2779 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  2780 MAY FAIL;
  2781 
  2782 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  2783 Isabelle's type classes, ^ on functions and relations has too general
  2784 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  2785 necessary to attach explicit type constraints;
  2786 
  2787 * HOL/Relation: the prefix name of the infix "O" has been changed from
  2788 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  2789 renamed accordingly (eg "compI" -> "rel_compI").
  2790 
  2791 * HOL: syntax translations now work properly with numerals and records
  2792 expressions;
  2793 
  2794 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  2795 of "lam" -- INCOMPATIBILITY;
  2796 
  2797 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  2798 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  2799 renamed "Product_Type.unit";
  2800 
  2801 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  2802 
  2803 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  2804 the "cases" method);
  2805 
  2806 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  2807 Florian Kammller);
  2808 
  2809 * HOL/IMP: updated and converted to new-style theory format; several
  2810 parts turned into readable document, with proper Isar proof texts and
  2811 some explanations (by Gerwin Klein);
  2812 
  2813 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  2814 
  2815 * HOL-Hyperreal is now a logic image;
  2816 
  2817 
  2818 *** HOLCF ***
  2819 
  2820 * Isar: consts/constdefs supports mixfix syntax for continuous
  2821 operations;
  2822 
  2823 * Isar: domain package adapted to new-style theory format, e.g. see
  2824 HOLCF/ex/Dnat.thy;
  2825 
  2826 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  2827 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  2828 lift.induct_tac, always use UU instead of Undef;
  2829 
  2830 * HOLCF/IMP: updated and converted to new-style theory;
  2831 
  2832 
  2833 *** ZF ***
  2834 
  2835 * Isar: proper integration of logic-specific tools and packages,
  2836 including theory commands '(co)inductive', '(co)datatype',
  2837 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  2838 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  2839 
  2840 * theory Main no longer includes AC; for the Axiom of Choice, base
  2841 your theory on Main_ZFC;
  2842 
  2843 * the integer library now covers quotients and remainders, with many
  2844 laws relating division to addition, multiplication, etc.;
  2845 
  2846 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  2847 typeless version of the formalism;
  2848 
  2849 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  2850 format;
  2851 
  2852 * ZF/Induct: new directory for examples of inductive definitions,
  2853 including theory Multiset for multiset orderings; converted to
  2854 new-style theory format;
  2855 
  2856 * ZF: many new theorems about lists, ordinals, etc.;
  2857 
  2858 
  2859 *** General ***
  2860 
  2861 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  2862 variable proof controls level of detail: 0 = no proofs (only oracle
  2863 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  2864 also ref manual for further ML interfaces;
  2865 
  2866 * Pure/axclass: removed obsolete ML interface
  2867 goal_subclass/goal_arity;
  2868 
  2869 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  2870 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  2871 separate tokens, so expressions involving minus need to be spaced
  2872 properly;
  2873 
  2874 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  2875 rather than "infixl" or "infixr";
  2876 
  2877 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  2878 sort constraint specifications in type inference; e.g. "x::_::foo"
  2879 ensures that the type of "x" is of sort "foo" (but not necessarily a
  2880 type variable);
  2881 
  2882 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  2883 control output of nested => (types); the default behavior is
  2884 "type_brackets";
  2885 
  2886 * Pure/syntax: builtin parse translation for "_constify" turns valued
  2887 tokens into AST constants;
  2888 
  2889 * Pure/syntax: prefer later declarations of translations and print
  2890 translation functions; potential INCOMPATIBILITY: need to reverse
  2891 multiple declarations for same syntax element constant;
  2892 
  2893 * Pure/show_hyps reset by default (in accordance to existing Isar
  2894 practice);
  2895 
  2896 * Provers/classical: renamed addaltern to addafter, addSaltern to
  2897 addSafter;
  2898 
  2899 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  2900 as well;
  2901 
  2902 * system: tested support for MacOS X; should be able to get Isabelle +
  2903 Proof General to work in a plain Terminal after installing Poly/ML
  2904 (e.g. from the Isabelle distribution area) and GNU bash alone
  2905 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  2906 support requires further installations, e.g. from
  2907 http://fink.sourceforge.net/);
  2908 
  2909 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  2910 
  2911 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  2912 of 40 MB), cf. ML_OPTIONS;
  2913 
  2914 * system: Proof General keywords specification is now part of the
  2915 Isabelle distribution (see etc/isar-keywords.el);
  2916 
  2917 * system: support for persistent Proof General sessions (refrain from
  2918 outdating all loaded theories on startup); user may create writable
  2919 logic images like this: ``isabelle -q HOL Test'';
  2920 
  2921 * system: smart selection of Isabelle process versus Isabelle
  2922 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  2923 run both "isabelle" and "Isabelle" even if file names are badly
  2924 damaged (executable inspects the case of the first letter of its own
  2925 name); added separate "isabelle-process" and "isabelle-interface";
  2926 
  2927 * system: refrain from any attempt at filtering input streams; no
  2928 longer support ``8bit'' encoding of old isabelle font, instead proper
  2929 iso-latin characters may now be used; the related isatools
  2930 "symbolinput" and "nonascii" have disappeared as well;
  2931 
  2932 * system: removed old "xterm" interface (the print modes "xterm" and
  2933 "xterm_color" are still available for direct use in a suitable
  2934 terminal);
  2935 
  2936 
  2937 
  2938 New in Isabelle99-2 (February 2001)
  2939 -----------------------------------
  2940 
  2941 *** Overview of INCOMPATIBILITIES ***
  2942 
  2943 * HOL: please note that theories in the Library and elsewhere often use the
  2944 new-style (Isar) format; to refer to their theorems in an ML script you must
  2945 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  2946 
  2947 * HOL: inductive package no longer splits induction rule aggressively,
  2948 but only as far as specified by the introductions given; the old
  2949 format may be recovered via ML function complete_split_rule or attribute
  2950 'split_rule (complete)';
  2951 
  2952 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  2953 gfp_Tarski to gfp_unfold;
  2954 
  2955 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  2956 
  2957 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  2958 relation); infix "^^" has been renamed "``"; infix "``" has been
  2959 renamed "`"; "univalent" has been renamed "single_valued";
  2960 
  2961 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  2962 operation;
  2963 
  2964 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  2965 
  2966 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  2967 
  2968 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  2969 consequence, it is no longer monotonic wrt. the local goal context
  2970 (which is now passed through the inductive cases);
  2971 
  2972 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  2973 \<gg> to \<ggreater>;
  2974 
  2975 
  2976 *** Document preparation ***
  2977 
  2978 * \isabellestyle{NAME} selects version of Isabelle output (currently
  2979 available: are "it" for near math-mode best-style output, "sl" for
  2980 slanted text style, and "tt" for plain type-writer; if no
  2981 \isabellestyle command is given, output is according to slanted
  2982 type-writer);
  2983 
  2984 * support sub/super scripts (for single symbols only), input syntax is
  2985 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  2986 
  2987 * some more standard symbols; see Appendix A of the system manual for
  2988 the complete list of symbols defined in isabellesym.sty;
  2989 
  2990 * improved isabelle style files; more abstract symbol implementation
  2991 (should now use \isamath{...} and \isatext{...} in custom symbol
  2992 definitions);
  2993 
  2994 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  2995 state; Note that presentation of goal states does not conform to
  2996 actual human-readable proof documents.  Please do not include goal
  2997 states into document output unless you really know what you are doing!
  2998 
  2999 * proper indentation of antiquoted output with proportional LaTeX
  3000 fonts;
  3001 
  3002 * no_document ML operator temporarily disables LaTeX document
  3003 generation;
  3004 
  3005 * isatool unsymbolize tunes sources for plain ASCII communication;
  3006 
  3007 
  3008 *** Isar ***
  3009 
  3010 * Pure: Isar now suffers initial goal statements to contain unbound
  3011 schematic variables (this does not conform to actual readable proof
  3012 documents, due to unpredictable outcome and non-compositional proof
  3013 checking); users who know what they are doing may use schematic goals
  3014 for Prolog-style synthesis of proven results;
  3015 
  3016 * Pure: assumption method (an implicit finishing) now handles actual
  3017 rules as well;
  3018 
  3019 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  3020 initial goal, declare "that" only as Pure intro (only for single
  3021 steps); the "that" rule assumption may now be involved in implicit
  3022 finishing, thus ".." becomes a feasible for trivial obtains;
  3023 
  3024 * Pure: default proof step now includes 'intro_classes'; thus trivial
  3025 instance proofs may be performed by "..";
  3026 
  3027 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  3028 statements as well;
  3029 
  3030 * Pure: more robust selection of calculational rules;
  3031 
  3032 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  3033 rule (as well as the assumption rule);
  3034 
  3035 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  3036 lemmas, using the graph browser tool;
  3037 
  3038 * Pure: predict failure of "show" in interactive mode;
  3039 
  3040 * Pure: 'thms_containing' now takes actual terms as arguments;
  3041 
  3042 * HOL: improved method 'induct' --- now handles non-atomic goals
  3043 (potential INCOMPATIBILITY); tuned error handling;
  3044 
  3045 * HOL: cases and induct rules now provide explicit hints about the
  3046 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  3047 any remaining facts are inserted into the goal verbatim;
  3048 
  3049 * HOL: local contexts (aka cases) may now contain term bindings as
  3050 well; the 'cases' and 'induct' methods new provide a ?case binding for
  3051 the result to be shown in each case;
  3052 
  3053 * HOL: added 'recdef_tc' command;
  3054 
  3055 * isatool convert assists in eliminating legacy ML scripts;
  3056 
  3057 
  3058 *** HOL ***
  3059 
  3060 * HOL/Library: a collection of generic theories to be used together
  3061 with main HOL; the theory loader path already includes this directory
  3062 by default; the following existing theories have been moved here:
  3063 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  3064 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  3065 
  3066 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  3067 modelling and verification task performed in Isabelle/HOL +
  3068 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  3069 
  3070 * HOL/Algebra: special summation operator SUM no longer exists, it has
  3071 been replaced by setsum; infix 'assoc' now has priority 50 (like
  3072 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  3073 'domain', this makes the theory consistent with mathematical
  3074 literature;
  3075 
  3076 * HOL basics: added overloaded operations "inverse" and "divide"
  3077 (infix "/"), syntax for generic "abs" operation, generic summation
  3078 operator \<Sum>;
  3079 
  3080 * HOL/typedef: simplified package, provide more useful rules (see also
  3081 HOL/subset.thy);
  3082 
  3083 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  3084 now expressed as a proper nested rule (old-style tactic scripts may
  3085 require atomize_strip_tac to cope with non-atomic premises);
  3086 
  3087 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  3088 to "split_conv" (old name still available for compatibility);
  3089 
  3090 * HOL: improved concrete syntax for strings (e.g. allows translation
  3091 rules with string literals);
  3092 
  3093 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  3094  and Fleuriot's mechanization of analysis, including the transcendental
  3095  functions for the reals;
  3096 
  3097 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  3098 
  3099 
  3100 *** CTT ***
  3101 
  3102 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  3103 "lam" is displayed as TWO lambda-symbols
  3104 
  3105 * CTT: theory Main now available, containing everything (that is, Bool
  3106 and Arith);
  3107 
  3108 
  3109 *** General ***
  3110 
  3111 * Pure: the Simplifier has been implemented properly as a derived rule
  3112 outside of the actual kernel (at last!); the overall performance
  3113 penalty in practical applications is about 50%, while reliability of
  3114 the Isabelle inference kernel has been greatly improved;
  3115 
  3116 * print modes "brackets" and "no_brackets" control output of nested =>
  3117 (types) and ==> (props); the default behaviour is "brackets";
  3118 
  3119 * Provers: fast_tac (and friends) now handle actual object-logic rules
  3120 as assumptions as well;
  3121 
  3122 * system: support Poly/ML 4.0;
  3123 
  3124 * system: isatool install handles KDE version 1 or 2;
  3125 
  3126 
  3127 
  3128 New in Isabelle99-1 (October 2000)
  3129 ----------------------------------
  3130 
  3131 *** Overview of INCOMPATIBILITIES ***
  3132 
  3133 * HOL: simplification of natural numbers is much changed; to partly
  3134 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  3135 issue the following ML commands:
  3136 
  3137   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  3138   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  3139 
  3140 * HOL: simplification no longer dives into case-expressions; this is
  3141 controlled by "t.weak_case_cong" for each datatype t;
  3142 
  3143 * HOL: nat_less_induct renamed to less_induct;
  3144 
  3145 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  3146 fixsome to patch .thy and .ML sources automatically;
  3147 
  3148   select_equality  -> some_equality
  3149   select_eq_Ex     -> some_eq_ex
  3150   selectI2EX       -> someI2_ex
  3151   selectI2         -> someI2
  3152   selectI          -> someI
  3153   select1_equality -> some1_equality
  3154   Eps_sym_eq       -> some_sym_eq_trivial
  3155   Eps_eq           -> some_eq_trivial
  3156 
  3157 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  3158 
  3159 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  3160 instead);
  3161 
  3162 * HOL: the recursion equations generated by 'recdef' are now called
  3163 f.simps instead of f.rules;
  3164 
  3165 * HOL: qed_spec_mp now also handles bounded ALL as well;
  3166 
  3167 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  3168 sometimes be needed;
  3169 
  3170 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  3171 
  3172 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  3173 
  3174 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  3175 product is now "<*>" instead of "Times"; the lexicographic product is
  3176 now "<*lex*>" instead of "**";
  3177 
  3178 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  3179 of main HOL, but was unused); better use HOL's datatype package;
  3180 
  3181 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  3182 the old syntax may be recovered as follows:
  3183 
  3184   syntax (symbols)
  3185     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  3186       (infixl "\\<oplus>" 100)
  3187 
  3188 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3189 
  3190 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  3191 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  3192 internally;
  3193 
  3194 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  3195 changed from A/r to A//r;
  3196 
  3197 * ZF: new treatment of arithmetic (nat & int) may break some old
  3198 proofs;
  3199 
  3200 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  3201 rulify -> rule_format, elimify -> elim_format, ...);
  3202 
  3203 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3204 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  3205 should have to change intro!! to intro? only); replaced "delrule" by
  3206 "rule del";
  3207 
  3208 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  3209 
  3210 * Provers: strengthened force_tac by using new first_best_tac;
  3211 
  3212 * LaTeX document preparation: several changes of isabelle.sty (see
  3213 lib/texinputs);
  3214 
  3215 
  3216 *** Document preparation ***
  3217 
  3218 * formal comments (text blocks etc.) in new-style theories may now
  3219 contain antiquotations of thm/prop/term/typ/text to be presented
  3220 according to latex print mode; concrete syntax is like this:
  3221 @{term[show_types] "f(x) = a + x"};
  3222 
  3223 * isatool mkdir provides easy setup of Isabelle session directories,
  3224 including proper document sources;
  3225 
  3226 * generated LaTeX sources are now deleted after successful run
  3227 (isatool document -c); may retain a copy somewhere else via -D option
  3228 of isatool usedir;
  3229 
  3230 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  3231 style files, achieving self-contained LaTeX sources and simplifying
  3232 LaTeX debugging;
  3233 
  3234 * old-style theories now produce (crude) LaTeX output as well;
  3235 
  3236 * browser info session directories are now self-contained (may be put
  3237 on WWW server seperately); improved graphs of nested sessions; removed
  3238 graph for 'all sessions';
  3239 
  3240 * several improvements in isabelle style files; \isabellestyle{it}
  3241 produces fake math mode output; \isamarkupheader is now \section by
  3242 default; see lib/texinputs/isabelle.sty etc.;
  3243 
  3244 
  3245 *** Isar ***
  3246 
  3247 * Isar/Pure: local results and corresponding term bindings are now
  3248 subject to Hindley-Milner polymorphism (similar to ML); this
  3249 accommodates incremental type-inference very nicely;
  3250 
  3251 * Isar/Pure: new derived language element 'obtain' supports
  3252 generalized existence reasoning;
  3253 
  3254 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  3255 support accumulation of results, without applying any rules yet;
  3256 useful to collect intermediate results without explicit name
  3257 references, and for use with transitivity rules with more than 2
  3258 premises;
  3259 
  3260 * Isar/Pure: scalable support for case-analysis type proofs: new
  3261 'case' language element refers to local contexts symbolically, as
  3262 produced by certain proof methods; internally, case names are attached
  3263 to theorems as "tags";
  3264 
  3265 * Isar/Pure: theory command 'hide' removes declarations from
  3266 class/type/const name spaces;
  3267 
  3268 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  3269 indicate potential overloading;
  3270 
  3271 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  3272 
  3273 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  3274 "{a,b,c}" instead of {a,b,c};
  3275 
  3276 * Isar/Pure now provides its own version of intro/elim/dest
  3277 attributes; useful for building new logics, but beware of confusion
  3278 with the version in Provers/classical;
  3279 
  3280 * Isar/Pure: the local context of (non-atomic) goals is provided via
  3281 case name 'antecedent';
  3282 
  3283 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  3284 to the current context is now done automatically);
  3285 
  3286 * Isar/Pure: theory command 'method_setup' provides a simple interface
  3287 for definining proof methods in ML;
  3288 
  3289 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3290 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  3291 most cases, one should have to change intro!! to intro? only);
  3292 replaced "delrule" by "rule del";
  3293 
  3294 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  3295 'symmetric' attribute (the latter supercedes [RS sym]);
  3296 
  3297 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  3298 method modifier); 'simp' method: 'only:' modifier removes loopers as
  3299 well (including splits);
  3300 
  3301 * Isar/Provers: Simplifier and Classical methods now support all kind
  3302 of modifiers used in the past, including 'cong', 'iff', etc.
  3303 
  3304 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  3305 of Simplifier and Classical reasoner);
  3306 
  3307 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  3308 now support named cases; major packages (inductive, datatype, primrec,
  3309 recdef) support case names and properly name parameters;
  3310 
  3311 * Isar/HOL: new transitivity rules for substitution in inequalities --
  3312 monotonicity conditions are extracted to be proven at end of
  3313 calculations;
  3314 
  3315 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  3316 method anyway;
  3317 
  3318 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  3319 split_if split_if_asm; datatype package provides theorems foo.splits =
  3320 foo.split foo.split_asm for each datatype;
  3321 
  3322 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  3323 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  3324 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  3325 use "(cases (simplified))" method in proper proof texts);
  3326 
  3327 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  3328 
  3329 * Isar: names of theorems etc. may be natural numbers as well;
  3330 
  3331 * Isar: 'pr' command: optional arguments for goals_limit and
  3332 ProofContext.prems_limit; no longer prints theory contexts, but only
  3333 proof states;
  3334 
  3335 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  3336 additional print modes to be specified; e.g. "pr(latex)" will print
  3337 proof state according to the Isabelle LaTeX style;
  3338 
  3339 * Isar: improved support for emulating tactic scripts, including proof
  3340 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  3341 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  3342 (for HOL datatypes);
  3343 
  3344 * Isar: simplified (more robust) goal selection of proof methods: 1st
  3345 goal, all goals, or explicit goal specifier (tactic emulation); thus
  3346 'proof method scripts' have to be in depth-first order;
  3347 
  3348 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  3349 
  3350 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  3351 should instead use individual commands for printing items
  3352 (print_commands, print_methods etc.);
  3353 
  3354 * Isar: added 'nothing' --- the empty list of theorems;
  3355 
  3356 
  3357 *** HOL ***
  3358 
  3359 * HOL/MicroJava: formalization of a fragment of Java, together with a
  3360 corresponding virtual machine and a specification of its bytecode
  3361 verifier and a lightweight bytecode verifier, including proofs of
  3362 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  3363 Cornelia Pusch (see also the homepage of project Bali at
  3364 http://isabelle.in.tum.de/Bali/);
  3365 
  3366 * HOL/Algebra: new theory of rings and univariate polynomials, by
  3367 Clemens Ballarin;
  3368 
  3369 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  3370 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  3371 Rasmussen;
  3372 
  3373 * HOL/Lattice: fundamental concepts of lattice theory and order
  3374 structures, including duals, properties of bounds versus algebraic
  3375 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  3376 Theorem for complete lattices etc.; may also serve as a demonstration
  3377 for abstract algebraic reasoning using axiomatic type classes, and
  3378 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  3379 
  3380 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  3381 von Oheimb;
  3382 
  3383 * HOL/IMPP: extension of IMP with local variables and mutually
  3384 recursive procedures, by David von Oheimb;
  3385 
  3386 * HOL/Lambda: converted into new-style theory and document;
  3387 
  3388 * HOL/ex/Multiquote: example of multiple nested quotations and
  3389 anti-quotations -- basically a generalized version of de-Bruijn
  3390 representation; very useful in avoiding lifting of operations;
  3391 
  3392 * HOL/record: added general record equality rule to simpset; fixed
  3393 select-update simplification procedure to handle extended records as
  3394 well; admit "r" as field name;
  3395 
  3396 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  3397 other numeric types and also as the identity of groups, rings, etc.;
  3398 
  3399 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  3400 Types nat and int belong to this axclass;
  3401 
  3402 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  3403    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  3404    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  3405   two terms #m*u and #n*u are replaced by #(m+n)*u
  3406     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  3407   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  3408     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  3409 
  3410 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  3411 powerful prover for predicate logic but knows nothing of clasets; see
  3412 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  3413 
  3414 * HOL: new version of "case_tac" subsumes both boolean case split and
  3415 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  3416 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  3417 
  3418 * HOL: simplification no longer dives into case-expressions: only the
  3419 selector expression is simplified, but not the remaining arms; to
  3420 enable full simplification of case-expressions for datatype t, you may
  3421 remove t.weak_case_cong from the simpset, either globally (Delcongs
  3422 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  3423 
  3424 * HOL/recdef: the recursion equations generated by 'recdef' for
  3425 function 'f' are now called f.simps instead of f.rules; if all
  3426 termination conditions are proved automatically, these simplification
  3427 rules are added to the simpset, as in primrec; rules may be named
  3428 individually as well, resulting in a separate list of theorems for
  3429 each equation;
  3430 
  3431 * HOL/While is a new theory that provides a while-combinator. It
  3432 permits the definition of tail-recursive functions without the
  3433 provision of a termination measure. The latter is necessary once the
  3434 invariant proof rule for while is applied.
  3435 
  3436 * HOL: new (overloaded) notation for the set of elements below/above
  3437 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  3438 
  3439 * HOL: theorems impI, allI, ballI bound as "strip";
  3440 
  3441 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  3442 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  3443 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  3444 
  3445 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3446 
  3447 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  3448 main HOL, but was unused);
  3449 
  3450 * HOL: fewer consts declared as global (e.g. have to refer to
  3451 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  3452 
  3453 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  3454 in case of overlap with user translations (e.g. judgements over
  3455 tuples); (note that the underlying logical represenation is still
  3456 bogus);
  3457 
  3458 
  3459 *** ZF ***
  3460 
  3461 * ZF: simplification automatically cancels common terms in arithmetic
  3462 expressions over nat and int;
  3463 
  3464 * ZF: new treatment of nat to minimize type-checking: all operators
  3465 coerce their operands to a natural number using the function natify,
  3466 making the algebraic laws unconditional;
  3467 
  3468 * ZF: as above, for int: operators coerce their operands to an integer
  3469 using the function intify;
  3470 
  3471 * ZF: the integer library now contains many of the usual laws for the
  3472 orderings, including $<=, and monotonicity laws for $+ and $*;
  3473 
  3474 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  3475 simplification;
  3476 
  3477 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  3478 to the simplifier and classical reasoner simultaneously;
  3479 
  3480 
  3481 *** General ***
  3482 
  3483 * Provers: blast_tac now handles actual object-logic rules as
  3484 assumptions; note that auto_tac uses blast_tac internally as well;
  3485 
  3486 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  3487 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  3488 
  3489 * Provers: delrules now handles destruct rules as well (no longer need
  3490 explicit make_elim);
  3491 
  3492 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  3493   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3494 use instead the strong form,
  3495   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3496 in HOL, FOL and ZF the function cla_make_elim will create such rules
  3497 from destruct-rules;
  3498 
  3499 * Provers: Simplifier.easy_setup provides a fast path to basic
  3500 Simplifier setup for new object-logics;
  3501 
  3502 * Pure: AST translation rules no longer require constant head on LHS;
  3503 
  3504 * Pure: improved name spaces: ambiguous output is qualified; support
  3505 for hiding of names;
  3506 
  3507 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  3508 XSYMBOL_HOME; no longer need to do manual configuration in most
  3509 situations;
  3510 
  3511 * system: compression of ML heaps images may now be controlled via -c
  3512 option of isabelle and isatool usedir (currently only observed by
  3513 Poly/ML);
  3514 
  3515 * system: isatool installfonts may handle X-Symbol fonts as well (very
  3516 useful for remote X11);
  3517 
  3518 * system: provide TAGS file for Isabelle sources;
  3519 
  3520 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  3521 order;
  3522 
  3523 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  3524 timing flag supersedes proof_timing and Toplevel.trace;
  3525 
  3526 * ML: new combinators |>> and |>>> for incremental transformations
  3527 with secondary results (e.g. certain theory extensions):
  3528 
  3529 * ML: PureThy.add_defs gets additional argument to indicate potential
  3530 overloading (usually false);
  3531 
  3532 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  3533 results;
  3534 
  3535 
  3536 
  3537 New in Isabelle99 (October 1999)
  3538 --------------------------------
  3539 
  3540 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3541 
  3542 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  3543 are no longer simplified.  (This allows the simplifier to unfold recursive
  3544 functional programs.)  To restore the old behaviour, declare
  3545 
  3546     Delcongs [if_weak_cong];
  3547 
  3548 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  3549 complement;
  3550 
  3551 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  3552 
  3553 * HOL/datatype: mutual_induct_tac no longer exists --
  3554   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  3555 
  3556 * HOL/typedef: fixed type inference for representing set; type
  3557 arguments now have to occur explicitly on the rhs as type constraints;
  3558 
  3559 * ZF: The con_defs part of an inductive definition may no longer refer
  3560 to constants declared in the same theory;
  3561 
  3562 * HOL, ZF: the function mk_cases, generated by the inductive
  3563 definition package, has lost an argument.  To simplify its result, it
  3564 uses the default simpset instead of a supplied list of theorems.
  3565 
  3566 * HOL/List: the constructors of type list are now Nil and Cons;
  3567 
  3568 * Simplifier: the type of the infix ML functions
  3569         setSSolver addSSolver setSolver addSolver
  3570 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  3571 for packaging solvers. A solver is created via
  3572         mk_solver: string -> (thm list -> int -> tactic) -> solver
  3573 where the string argument is only a comment.
  3574 
  3575 
  3576 *** Proof tools ***
  3577 
  3578 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  3579 decision procedure for linear arithmetic. Currently it is used for
  3580 types `nat', `int', and `real' in HOL (see below); it can, should and
  3581 will be instantiated for other types and logics as well.
  3582 
  3583 * The simplifier now accepts rewrite rules with flexible heads, eg
  3584      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  3585   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  3586   matching.
  3587 
  3588 
  3589 *** General ***
  3590 
  3591 * New Isabelle/Isar subsystem provides an alternative to traditional
  3592 tactical theorem proving; together with the ProofGeneral/isar user
  3593 interface it offers an interactive environment for developing human
  3594 readable proof documents (Isar == Intelligible semi-automated
  3595 reasoning); for further information see isatool doc isar-ref,
  3596 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  3597 
  3598 * improved and simplified presentation of theories: better HTML markup
  3599 (including colors), graph views in several sizes; isatool usedir now
  3600 provides a proper interface for user theories (via -P option); actual
  3601 document preparation based on (PDF)LaTeX is available as well (for
  3602 new-style theories only); see isatool doc system for more information;
  3603 
  3604 * native support for Proof General, both for classic Isabelle and
  3605 Isabelle/Isar;
  3606 
  3607 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  3608 using the graph browser tool;
  3609 
  3610 * Isabelle manuals now also available as PDF;
  3611 
  3612 * theory loader rewritten from scratch (may not be fully
  3613 bug-compatible); old loadpath variable has been replaced by show_path,
  3614 add_path, del_path, reset_path functions; new operations such as
  3615 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  3616 isatool doc ref);
  3617 
  3618 * improved isatool install: option -k creates KDE application icon,
  3619 option -p DIR installs standalone binaries;
  3620 
  3621 * added ML_PLATFORM setting (useful for cross-platform installations);
  3622 more robust handling of platform specific ML images for SML/NJ;
  3623 
  3624 * the settings environment is now statically scoped, i.e. it is never
  3625 created again in sub-processes invoked from isabelle, isatool, or
  3626 Isabelle;
  3627 
  3628 * path element specification '~~' refers to '$ISABELLE_HOME';
  3629 
  3630 * in locales, the "assumes" and "defines" parts may be omitted if
  3631 empty;
  3632 
  3633 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  3634 long arrows);
  3635 
  3636 * new print_mode "HTML";
  3637 
  3638 * new flag show_tags controls display of tags of theorems (which are
  3639 basically just comments that may be attached by some tools);
  3640 
  3641 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  3642 mode and goal output format:
  3643 
  3644 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  3645 244c244
  3646 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  3647 ---
  3648 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  3649 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  3650 181c181
  3651 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  3652 ---
  3653 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  3654 
  3655 * function bind_thms stores lists of theorems (cf. bind_thm);
  3656 
  3657 * new shorthand tactics ftac, eatac, datac, fatac;
  3658 
  3659 * qed (and friends) now accept "" as result name; in that case the
  3660 theorem is not stored, but proper checks and presentation of the
  3661 result still apply;
  3662 
  3663 * theorem database now also indexes constants "Trueprop", "all",
  3664 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  3665 
  3666 
  3667 *** HOL ***
  3668 
  3669 ** HOL arithmetic **
  3670 
  3671 * There are now decision procedures for linear arithmetic over nat and
  3672 int:
  3673 
  3674 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  3675 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  3676 are treated as atomic; subformulae not involving type `nat' or `int'
  3677 are ignored; quantified subformulae are ignored unless they are
  3678 positive universal or negative existential. The tactic has to be
  3679 invoked by hand and can be a little bit slow. In particular, the
  3680 running time is exponential in the number of occurrences of `min' and
  3681 `max', and `-' on `nat'.
  3682 
  3683 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  3684 (negated) (in)equalities among the premises and the conclusion into
  3685 account (i.e. no compound formulae) and does not know about `min' and
  3686 `max', and `-' on `nat'. It is fast and is used automatically by the
  3687 simplifier.
  3688 
  3689 NB: At the moment, these decision procedures do not cope with mixed
  3690 nat/int formulae where the two parts interact, such as `m < n ==>
  3691 int(m) < int(n)'.
  3692 
  3693 * HOL/Numeral provides a generic theory of numerals (encoded
  3694 efficiently as bit strings); setup for types nat/int/real is in place;
  3695 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  3696 int, existing theories and proof scripts may require a few additional
  3697 type constraints;
  3698 
  3699 * integer division and remainder can now be performed on constant
  3700 arguments;
  3701 
  3702 * many properties of integer multiplication, division and remainder
  3703 are now available;
  3704 
  3705 * An interface to the Stanford Validity Checker (SVC) is available through the
  3706 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  3707 are proved automatically.  SVC must be installed separately, and its results
  3708 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  3709 invocation of the underlying oracle).  For SVC see
  3710   http://verify.stanford.edu/SVC
  3711 
  3712 * IsaMakefile: the HOL-Real target now builds an actual image;
  3713 
  3714 
  3715 ** HOL misc **
  3716 
  3717 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  3718 (in Isabelle/Isar) -- by Gertrud Bauer;
  3719 
  3720 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  3721 analysis for assembly languages with subtypes;
  3722 
  3723 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  3724 -- avoids syntactic ambiguities and treats state, transition, and
  3725 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  3726 changed syntax and (many) tactics;
  3727 
  3728 * HOL/inductive: Now also handles more general introduction rules such
  3729   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  3730   theorems are now maintained within the theory (maintained via the
  3731   "mono" attribute);
  3732 
  3733 * HOL/datatype: Now also handles arbitrarily branching datatypes
  3734   (using function types) such as
  3735 
  3736   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  3737 
  3738 * HOL/record: record_simproc (part of the default simpset) takes care
  3739 of selectors applied to updated records; record_split_tac is no longer
  3740 part of the default claset; update_defs may now be removed from the
  3741 simpset in many cases; COMPATIBILITY: old behavior achieved by
  3742 
  3743   claset_ref () := claset() addSWrapper record_split_wrapper;
  3744   Delsimprocs [record_simproc]
  3745 
  3746 * HOL/typedef: fixed type inference for representing set; type
  3747 arguments now have to occur explicitly on the rhs as type constraints;
  3748 
  3749 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  3750 names rather than an ML expression;
  3751 
  3752 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  3753 supplied later.  Program schemes can be defined, such as
  3754     "While B C s = (if B s then While B C (C s) else s)"
  3755 where the well-founded relation can be chosen after B and C have been given.
  3756 
  3757 * HOL/List: the constructors of type list are now Nil and Cons;
  3758 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  3759 course, ML tools referring to List.list.op # etc. have to be adapted;
  3760 
  3761 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  3762 disabled by default; run isabelle with option -m HOL to get back to
  3763 the original Gordon/HOL-style output;
  3764 
  3765 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  3766 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  3767 
  3768 * HOL basic syntax simplified (more orthogonal): all variants of
  3769 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  3770 Eps operator is provided as well: "SOME x. P[x]";
  3771 
  3772 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  3773 
  3774 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  3775 thus available for user theories;
  3776 
  3777 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  3778 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  3779 time;
  3780 
  3781 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  3782 several times and then mp;
  3783 
  3784 
  3785 *** LK ***
  3786 
  3787 * the notation <<...>> is now available as a notation for sequences of
  3788 formulas;
  3789 
  3790 * the simplifier is now installed
  3791 
  3792 * the axiom system has been generalized (thanks to Soren Heilmann)
  3793 
  3794 * the classical reasoner now has a default rule database
  3795 
  3796 
  3797 *** ZF ***
  3798 
  3799 * new primrec section allows primitive recursive functions to be given
  3800 directly (as in HOL) over datatypes and the natural numbers;
  3801 
  3802 * new tactics induct_tac and exhaust_tac for induction (or case
  3803 analysis) over datatypes and the natural numbers;
  3804 
  3805 * the datatype declaration of type T now defines the recursor T_rec;
  3806 
  3807 * simplification automatically does freeness reasoning for datatype
  3808 constructors;
  3809 
  3810 * automatic type-inference, with AddTCs command to insert new
  3811 type-checking rules;
  3812 
  3813 * datatype introduction rules are now added as Safe Introduction rules
  3814 to the claset;
  3815 
  3816 * the syntax "if P then x else y" is now available in addition to
  3817 if(P,x,y);
  3818 
  3819 
  3820 *** Internal programming interfaces ***
  3821 
  3822 * tuned simplifier trace output; new flag debug_simp;
  3823 
  3824 * structures Vartab / Termtab (instances of TableFun) offer efficient
  3825 tables indexed by indexname_ord / term_ord (compatible with aconv);
  3826 
  3827 * AxClass.axclass_tac lost the theory argument;
  3828 
  3829 * tuned current_goals_markers semantics: begin / end goal avoids
  3830 printing empty lines;
  3831 
  3832 * removed prs and prs_fn hook, which was broken because it did not
  3833 include \n in its semantics, forcing writeln to add one
  3834 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  3835 string -> unit if you really want to output text without newline;
  3836 
  3837 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  3838 plain output, interface builders may have to enable 'isabelle_font'
  3839 mode to get Isabelle font glyphs as before;
  3840 
  3841 * refined token_translation interface; INCOMPATIBILITY: output length
  3842 now of type real instead of int;
  3843 
  3844 * theory loader actions may be traced via new ThyInfo.add_hook
  3845 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  3846 your own database of information attached to *whole* theories -- as
  3847 opposed to intra-theory data slots offered via TheoryDataFun;
  3848 
  3849 * proper handling of dangling sort hypotheses (at last!);
  3850 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  3851 extra sort hypotheses that can be witnessed from the type signature;
  3852 the force_strip_shyps flag is gone, any remaining shyps are simply
  3853 left in the theorem (with a warning issued by strip_shyps_warning);
  3854 
  3855 
  3856 
  3857 New in Isabelle98-1 (October 1998)
  3858 ----------------------------------
  3859 
  3860 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3861 
  3862 * several changes of automated proof tools;
  3863 
  3864 * HOL: major changes to the inductive and datatype packages, including
  3865 some minor incompatibilities of theory syntax;
  3866 
  3867 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  3868 called `inj_on';
  3869 
  3870 * HOL: removed duplicate thms in Arith:
  3871   less_imp_add_less  should be replaced by  trans_less_add1
  3872   le_imp_add_le      should be replaced by  trans_le_add1
  3873 
  3874 * HOL: unary minus is now overloaded (new type constraints may be
  3875 required);
  3876 
  3877 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  3878 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  3879 now taken as an integer constant.
  3880 
  3881 * Pure: ML function 'theory_of' renamed to 'theory';
  3882 
  3883 
  3884 *** Proof tools ***
  3885 
  3886 * Simplifier:
  3887   1. Asm_full_simp_tac is now more aggressive.
  3888      1. It will sometimes reorient premises if that increases their power to
  3889         simplify.
  3890      2. It does no longer proceed strictly from left to right but may also
  3891         rotate premises to achieve further simplification.
  3892      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  3893      old Asm_full_simp_tac in that it does not rotate premises.
  3894   2. The simplifier now knows a little bit about nat-arithmetic.
  3895 
  3896 * Classical reasoner: wrapper mechanism for the classical reasoner now
  3897 allows for selected deletion of wrappers, by introduction of names for
  3898 wrapper functionals.  This implies that addbefore, addSbefore,
  3899 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  3900 and that adding two tactics with the same name overwrites the first
  3901 one (emitting a warning).
  3902   type wrapper = (int -> tactic) -> (int -> tactic)
  3903   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  3904   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  3905   delWrapper, delSWrapper: claset *  string            -> claset
  3906   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  3907 
  3908 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  3909 semantics; addbefore now affects only the unsafe part of step_tac
  3910 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  3911 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  3912 by Force_tac;
  3913 
  3914 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  3915 compWrapper; added safe wrapper (and access functions for it);
  3916 
  3917 * HOL/split_all_tac is now much faster and fails if there is nothing
  3918 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  3919 and the names of the automatically generated variables have changed.
  3920 split_all_tac has moved within claset() from unsafe wrappers to safe
  3921 wrappers, which means that !!-bound variables are split much more
  3922 aggressively, and safe_tac and clarify_tac now split such variables.
  3923 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  3924 Note: the same holds for record_split_tac, which does the job of
  3925 split_all_tac for record fields.
  3926 
  3927 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  3928 permanently to the default simpset using Addsplits just like
  3929 Addsimps. They can be removed via Delsplits just like
  3930 Delsimps. Lower-case versions are also available.
  3931 
  3932 * HOL/Simplifier: The rule split_if is now part of the default
  3933 simpset. This means that the simplifier will eliminate all occurrences
  3934 of if-then-else in the conclusion of a goal. To prevent this, you can
  3935 either remove split_if completely from the default simpset by
  3936 `Delsplits [split_if]' or remove it in a specific call of the
  3937 simplifier using `... delsplits [split_if]'.  You can also add/delete
  3938 other case splitting rules to/from the default simpset: every datatype
  3939 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  3940 t is the name of the datatype).
  3941 
  3942 * Classical reasoner / Simplifier combination: new force_tac (and
  3943 derivatives Force_tac, force) combines rewriting and classical
  3944 reasoning (and whatever other tools) similarly to auto_tac, but is
  3945 aimed to solve the given subgoal completely.
  3946 
  3947 
  3948 *** General ***
  3949 
  3950 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  3951 and `goalw': the theory is no longer needed as an explicit argument -
  3952 the current theory context is used; assumptions are no longer returned
  3953 at the ML-level unless one of them starts with ==> or !!; it is
  3954 recommended to convert to these new commands using isatool fixgoal
  3955 (backup your sources first!);
  3956 
  3957 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  3958 the current theory context, and 'theory' to lookup stored theories;
  3959 
  3960 * new theory section 'locale' for declaring constants, assumptions and
  3961 definitions that have local scope;
  3962 
  3963 * new theory section 'nonterminals' for purely syntactic types;
  3964 
  3965 * new theory section 'setup' for generic ML setup functions
  3966 (e.g. package initialization);
  3967 
  3968 * the distribution now includes Isabelle icons: see
  3969 lib/logo/isabelle-{small,tiny}.xpm;
  3970 
  3971 * isatool install - install binaries with absolute references to
  3972 ISABELLE_HOME/bin;
  3973 
  3974 * isatool logo -- create instances of the Isabelle logo (as EPS);
  3975 
  3976 * print mode 'emacs' reserved for Isamode;
  3977 
  3978 * support multiple print (ast) translations per constant name;
  3979 
  3980 * theorems involving oracles are now printed with a suffixed [!];
  3981 
  3982 
  3983 *** HOL ***
  3984 
  3985 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  3986 
  3987 * HOL/inductive package reorganized and improved: now supports mutual
  3988 definitions such as
  3989 
  3990   inductive EVEN ODD
  3991     intrs
  3992       null "0 : EVEN"
  3993       oddI "n : EVEN ==> Suc n : ODD"
  3994       evenI "n : ODD ==> Suc n : EVEN"
  3995 
  3996 new theorem list "elims" contains an elimination rule for each of the
  3997 recursive sets; inductive definitions now handle disjunctive premises
  3998 correctly (also ZF);
  3999 
  4000 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  4001 "mutual_induct" no longer exists - the induction rule is always
  4002 contained in "induct";
  4003 
  4004 
  4005 * HOL/datatype package re-implemented and greatly improved: now
  4006 supports mutually recursive datatypes such as
  4007 
  4008   datatype
  4009     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  4010             | SUM ('a aexp) ('a aexp)
  4011             | DIFF ('a aexp) ('a aexp)
  4012             | NUM 'a
  4013   and
  4014     'a bexp = LESS ('a aexp) ('a aexp)
  4015             | AND ('a bexp) ('a bexp)
  4016             | OR ('a bexp) ('a bexp)
  4017 
  4018 as well as indirectly recursive datatypes such as
  4019 
  4020   datatype
  4021     ('a, 'b) term = Var 'a
  4022                   | App 'b ((('a, 'b) term) list)
  4023 
  4024 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  4025 induction on mutually / indirectly recursive datatypes.
  4026 
  4027 Primrec equations are now stored in theory and can be accessed via
  4028 <function_name>.simps.
  4029 
  4030 INCOMPATIBILITIES:
  4031 
  4032   - Theories using datatypes must now have theory Datatype as an
  4033     ancestor.
  4034   - The specific <typename>.induct_tac no longer exists - use the
  4035     generic induct_tac instead.
  4036   - natE has been renamed to nat.exhaust - use exhaust_tac
  4037     instead of res_inst_tac ... natE. Note that the variable
  4038     names in nat.exhaust differ from the names in natE, this
  4039     may cause some "fragile" proofs to fail.
  4040   - The theorems split_<typename>_case and split_<typename>_case_asm
  4041     have been renamed to <typename>.split and <typename>.split_asm.
  4042   - Since default sorts of type variables are now handled correctly,
  4043     some datatype definitions may have to be annotated with explicit
  4044     sort constraints.
  4045   - Primrec definitions no longer require function name and type
  4046     of recursive argument.
  4047 
  4048 Consider using isatool fixdatatype to adapt your theories and proof
  4049 scripts to the new package (backup your sources first!).
  4050 
  4051 
  4052 * HOL/record package: considerably improved implementation; now
  4053 includes concrete syntax for record types, terms, updates; theorems
  4054 for surjective pairing and splitting !!-bound record variables; proof
  4055 support is as follows:
  4056 
  4057   1) standard conversions (selectors or updates applied to record
  4058 constructor terms) are part of the standard simpset;
  4059 
  4060   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  4061 made part of standard simpset and claset via addIffs;
  4062 
  4063   3) a tactic for record field splitting (record_split_tac) is part of
  4064 the standard claset (addSWrapper);
  4065 
  4066 To get a better idea about these rules you may retrieve them via
  4067 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  4068 the name of your record type.
  4069 
  4070 The split tactic 3) conceptually simplifies by the following rule:
  4071 
  4072   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  4073 
  4074 Thus any record variable that is bound by meta-all will automatically
  4075 blow up into some record constructor term, consequently the
  4076 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  4077 solve record problems automatically.
  4078 
  4079 
  4080 * reorganized the main HOL image: HOL/Integ and String loaded by
  4081 default; theory Main includes everything;
  4082 
  4083 * automatic simplification of integer sums and comparisons, using cancellation;
  4084 
  4085 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  4086 
  4087 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  4088 
  4089 * many new identities for unions, intersections, set difference, etc.;
  4090 
  4091 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  4092 called split_if, split_split, split_sum_case and split_nat_case (to go
  4093 with add/delsplits);
  4094 
  4095 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  4096 (?x::unit) = (); this is made part of the default simpset, which COULD
  4097 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  4098 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  4099 unit_abs_eta_conv is added in order to counter the effect of
  4100 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  4101 %u.f();
  4102 
  4103 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  4104 makes more sense);
  4105 
  4106 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4107   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4108   disjointness reasoning but breaking a few old proofs.
  4109 
  4110 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  4111 to 'converse' from 'inverse' (for compatibility with ZF and some
  4112 literature);
  4113 
  4114 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  4115 the well-founded relation;
  4116 
  4117 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  4118     Compl A.  The "Compl" syntax remains available as input syntax for this
  4119     release ONLY.
  4120 
  4121 * HOL/Update: new theory of function updates:
  4122     f(a:=b) == %x. if x=a then b else f x
  4123 may also be iterated as in f(a:=b,c:=d,...);
  4124 
  4125 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  4126 
  4127 * HOL/List:
  4128   - new function list_update written xs[i:=v] that updates the i-th
  4129     list position. May also be iterated as in xs[i:=a,j:=b,...].
  4130   - new function `upt' written [i..j(] which generates the list
  4131     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  4132     bound write [i..j], which is a shorthand for [i..j+1(].
  4133   - new lexicographic orderings and corresponding wellfoundedness theorems.
  4134 
  4135 * HOL/Arith:
  4136   - removed 'pred' (predecessor) function;
  4137   - generalized some theorems about n-1;
  4138   - many new laws about "div" and "mod";
  4139   - new laws about greatest common divisors (see theory ex/Primes);
  4140 
  4141 * HOL/Relation: renamed the relational operator r^-1 "converse"
  4142 instead of "inverse";
  4143 
  4144 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  4145   of the multiset ordering;
  4146 
  4147 * directory HOL/Real: a construction of the reals using Dedekind cuts
  4148   (not included by default);
  4149 
  4150 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  4151 
  4152 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  4153   programs, i.e. different program variables may have different types.
  4154 
  4155 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4156   [previously, this check worked only if the rewrite rule was unconditional]
  4157   Now rew can involve either definitions or equalities (either == or =).
  4158 
  4159 
  4160 *** ZF ***
  4161 
  4162 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  4163   only the theorems proved on ZF.ML;
  4164 
  4165 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4166   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4167   disjointness reasoning but breaking a few old proofs.
  4168 
  4169 * ZF/Update: new theory of function updates
  4170     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  4171   may also be iterated as in f(a:=b,c:=d,...);
  4172 
  4173 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  4174 
  4175 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4176   [previously, this check worked only if the rewrite rule was unconditional]
  4177   Now rew can involve either definitions or equalities (either == or =).
  4178 
  4179 * case_tac provided for compatibility with HOL
  4180     (like the old excluded_middle_tac, but with subgoals swapped)
  4181 
  4182 
  4183 *** Internal programming interfaces ***
  4184 
  4185 * Pure: several new basic modules made available for general use, see
  4186 also src/Pure/README;
  4187 
  4188 * improved the theory data mechanism to support encapsulation (data
  4189 kind name replaced by private Object.kind, acting as authorization
  4190 key); new type-safe user interface via functor TheoryDataFun; generic
  4191 print_data function becomes basically useless;
  4192 
  4193 * removed global_names compatibility flag -- all theory declarations
  4194 are qualified by default;
  4195 
  4196 * module Pure/Syntax now offers quote / antiquote translation
  4197 functions (useful for Hoare logic etc. with implicit dependencies);
  4198 see HOL/ex/Antiquote for an example use;
  4199 
  4200 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  4201 cterm -> thm;
  4202 
  4203 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  4204 subgoal;
  4205 
  4206 * Display.print_goals function moved to Locale.print_goals;
  4207 
  4208 * standard print function for goals supports current_goals_markers
  4209 variable for marking begin of proof, end of proof, start of goal; the
  4210 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  4211 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  4212 for example;
  4213 
  4214 
  4215 
  4216 New in Isabelle98 (January 1998)
  4217 --------------------------------
  4218 
  4219 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4220 
  4221 * changed lexical syntax of terms / types: dots made part of long
  4222 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  4223 
  4224 * simpset (and claset) reference variable replaced by functions
  4225 simpset / simpset_ref;
  4226 
  4227 * no longer supports theory aliases (via merge) and non-trivial
  4228 implicit merge of thms' signatures;
  4229 
  4230 * most internal names of constants changed due to qualified names;
  4231 
  4232 * changed Pure/Sequence interface (see Pure/seq.ML);
  4233 
  4234 
  4235 *** General Changes ***
  4236 
  4237 * hierachically structured name spaces (for consts, types, axms, thms
  4238 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  4239 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  4240 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  4241 long_names for fully qualified output names; NOTE: ML programs
  4242 (special tactics, packages etc.) referring to internal names may have
  4243 to be adapted to cope with fully qualified names; in case of severe
  4244 backward campatibility problems try setting 'global_names' at compile
  4245 time to have enrything declared within a flat name space; one may also
  4246 fine tune name declarations in theories via the 'global' and 'local'
  4247 section;
  4248 
  4249 * reimplemented the implicit simpset and claset using the new anytype
  4250 data filed in signatures; references simpset:simpset ref etc. are
  4251 replaced by functions simpset:unit->simpset and
  4252 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  4253 to patch your ML files accordingly;
  4254 
  4255 * HTML output now includes theory graph data for display with Java
  4256 applet or isatool browser; data generated automatically via isatool
  4257 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  4258 
  4259 * defs may now be conditional; improved rewrite_goals_tac to handle
  4260 conditional equations;
  4261 
  4262 * defs now admits additional type arguments, using TYPE('a) syntax;
  4263 
  4264 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  4265 creates a new theory node; implicit merge of thms' signatures is
  4266 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  4267 transfer:theory->thm->thm in (rare) cases;
  4268 
  4269 * improved handling of draft signatures / theories; draft thms (and
  4270 ctyps, cterms) are automatically promoted to real ones;
  4271 
  4272 * slightly changed interfaces for oracles: admit many per theory, named
  4273 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  4274 
  4275 * print_goals: optional output of const types (set show_consts and
  4276 show_types);
  4277 
  4278 * improved output of warnings (###) and errors (***);
  4279 
  4280 * subgoal_tac displays a warning if the new subgoal has type variables;
  4281 
  4282 * removed old README and Makefiles;
  4283 
  4284 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  4285 
  4286 * removed obsolete init_pps and init_database;
  4287 
  4288 * deleted the obsolete tactical STATE, which was declared by
  4289     fun STATE tacfun st = tacfun st st;
  4290 
  4291 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  4292 (which abbreviates $HOME);
  4293 
  4294 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  4295 use isatool fixseq to adapt your ML programs (this works for fully
  4296 qualified references to the Sequence structure only!);
  4297 
  4298 * use_thy no longer requires writable current directory; it always
  4299 reloads .ML *and* .thy file, if either one is out of date;
  4300 
  4301 
  4302 *** Classical Reasoner ***
  4303 
  4304 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  4305 tactics that use classical reasoning to simplify a subgoal without
  4306 splitting it into several subgoals;
  4307 
  4308 * Safe_tac: like safe_tac but uses the default claset;
  4309 
  4310 
  4311 *** Simplifier ***
  4312 
  4313 * added simplification meta rules:
  4314     (asm_)(full_)simplify: simpset -> thm -> thm;
  4315 
  4316 * simplifier.ML no longer part of Pure -- has to be loaded by object
  4317 logics (again);
  4318 
  4319 * added prems argument to simplification procedures;
  4320 
  4321 * HOL, FOL, ZF: added infix function `addsplits':
  4322   instead of `<simpset> setloop (split_tac <thms>)'
  4323   you can simply write `<simpset> addsplits <thms>'
  4324 
  4325 
  4326 *** Syntax ***
  4327 
  4328 * TYPE('a) syntax for type reflection terms;
  4329 
  4330 * no longer handles consts with name "" -- declare as 'syntax' instead;
  4331 
  4332 * pretty printer: changed order of mixfix annotation preference (again!);
  4333 
  4334 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  4335 
  4336 
  4337 *** HOL ***
  4338 
  4339 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4340   with `addloop' of the simplifier to faciliate case splitting in premises.
  4341 
  4342 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  4343 
  4344 * HOL/Auth: new protocol proofs including some for the Internet
  4345   protocol TLS;
  4346 
  4347 * HOL/Map: new theory of `maps' a la VDM;
  4348 
  4349 * HOL/simplifier: simplification procedures nat_cancel_sums for
  4350 cancelling out common nat summands from =, <, <= (in)equalities, or
  4351 differences; simplification procedures nat_cancel_factor for
  4352 cancelling common factor from =, <, <= (in)equalities over natural
  4353 sums; nat_cancel contains both kinds of procedures, it is installed by
  4354 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  4355 
  4356 * HOL/simplifier: terms of the form
  4357   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  4358   are rewritten to
  4359   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  4360   and those of the form
  4361   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  4362   are rewritten to
  4363   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  4364 
  4365 * HOL/datatype
  4366   Each datatype `t' now comes with a theorem `split_t_case' of the form
  4367 
  4368   P(t_case f1 ... fn x) =
  4369      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  4370         ...
  4371        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  4372      )
  4373 
  4374   and a theorem `split_t_case_asm' of the form
  4375 
  4376   P(t_case f1 ... fn x) =
  4377     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  4378         ...
  4379        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  4380      )
  4381   which can be added to a simpset via `addsplits'. The existing theorems
  4382   expand_list_case and expand_option_case have been renamed to
  4383   split_list_case and split_option_case.
  4384 
  4385 * HOL/Arithmetic:
  4386   - `pred n' is automatically converted to `n-1'.
  4387     Users are strongly encouraged not to use `pred' any longer,
  4388     because it will disappear altogether at some point.
  4389   - Users are strongly encouraged to write "0 < n" rather than
  4390     "n ~= 0". Theorems and proof tools have been modified towards this
  4391     `standard'.
  4392 
  4393 * HOL/Lists:
  4394   the function "set_of_list" has been renamed "set" (and its theorems too);
  4395   the function "nth" now takes its arguments in the reverse order and
  4396   has acquired the infix notation "!" as in "xs!n".
  4397 
  4398 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  4399 
  4400 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  4401   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  4402 
  4403 * HOL/record: extensible records with schematic structural subtyping
  4404 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  4405 still lacks various theorems and concrete record syntax;
  4406 
  4407 
  4408 *** HOLCF ***
  4409 
  4410 * removed "axioms" and "generated by" sections;
  4411 
  4412 * replaced "ops" section by extended "consts" section, which is capable of
  4413   handling the continuous function space "->" directly;
  4414 
  4415 * domain package:
  4416   . proves theorems immediately and stores them in the theory,
  4417   . creates hierachical name space,
  4418   . now uses normal mixfix annotations (instead of cinfix...),
  4419   . minor changes to some names and values (for consistency),
  4420   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  4421   . separator between mutual domain defs: changed "," to "and",
  4422   . improved handling of sort constraints;  now they have to
  4423     appear on the left-hand side of the equations only;
  4424 
  4425 * fixed LAM <x,y,zs>.b syntax;
  4426 
  4427 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  4428 adm (%x. P (t x)), where P is chainfinite and t continuous;
  4429 
  4430 
  4431 *** FOL and ZF ***
  4432 
  4433 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4434   with `addloop' of the simplifier to faciliate case splitting in premises.
  4435 
  4436 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  4437 in HOL, they strip ALL and --> from proved theorems;
  4438 
  4439 
  4440 
  4441 New in Isabelle94-8 (May 1997)
  4442 ------------------------------
  4443 
  4444 *** General Changes ***
  4445 
  4446 * new utilities to build / run / maintain Isabelle etc. (in parts
  4447 still somewhat experimental); old Makefiles etc. still functional;
  4448 
  4449 * new 'Isabelle System Manual';
  4450 
  4451 * INSTALL text, together with ./configure and ./build scripts;
  4452 
  4453 * reimplemented type inference for greater efficiency, better error
  4454 messages and clean internal interface;
  4455 
  4456 * prlim command for dealing with lots of subgoals (an easier way of
  4457 setting goals_limit);
  4458 
  4459 
  4460 *** Syntax ***
  4461 
  4462 * supports alternative (named) syntax tables (parser and pretty
  4463 printer); internal interface is provided by add_modesyntax(_i);
  4464 
  4465 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  4466 be used in conjunction with the Isabelle symbol font; uses the
  4467 "symbols" syntax table;
  4468 
  4469 * added token_translation interface (may translate name tokens in
  4470 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  4471 the current print_mode); IMPORTANT: user print translation functions
  4472 are responsible for marking newly introduced bounds
  4473 (Syntax.mark_boundT);
  4474 
  4475 * token translations for modes "xterm" and "xterm_color" that display
  4476 names in bold, underline etc. or colors (which requires a color
  4477 version of xterm);
  4478 
  4479 * infixes may now be declared with names independent of their syntax;
  4480 
  4481 * added typed_print_translation (like print_translation, but may
  4482 access type of constant);
  4483 
  4484 
  4485 *** Classical Reasoner ***
  4486 
  4487 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  4488 some limitations.  Blast_tac...
  4489   + ignores addss, addbefore, addafter; this restriction is intrinsic
  4490   + ignores elimination rules that don't have the correct format
  4491         (the conclusion MUST be a formula variable)
  4492   + ignores types, which can make HOL proofs fail
  4493   + rules must not require higher-order unification, e.g. apply_type in ZF
  4494     [message "Function Var's argument not a bound variable" relates to this]
  4495   + its proof strategy is more general but can actually be slower
  4496 
  4497 * substitution with equality assumptions no longer permutes other
  4498 assumptions;
  4499 
  4500 * minor changes in semantics of addafter (now called addaltern); renamed
  4501 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  4502 (and access functions for it);
  4503 
  4504 * improved combination of classical reasoner and simplifier:
  4505   + functions for handling clasimpsets
  4506   + improvement of addss: now the simplifier is called _after_ the
  4507     safe steps.
  4508   + safe variant of addss called addSss: uses safe simplifications
  4509     _during_ the safe steps. It is more complete as it allows multiple
  4510     instantiations of unknowns (e.g. with slow_tac).
  4511 
  4512 *** Simplifier ***
  4513 
  4514 * added interface for simplification procedures (functions that
  4515 produce *proven* rewrite rules on the fly, depending on current
  4516 redex);
  4517 
  4518 * ordering on terms as parameter (used for ordered rewriting);
  4519 
  4520 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  4521 
  4522 * the solver is now split into a safe and an unsafe part.
  4523 This should be invisible for the normal user, except that the
  4524 functions setsolver and addsolver have been renamed to setSolver and
  4525 addSolver; added safe_asm_full_simp_tac;
  4526 
  4527 
  4528 *** HOL ***
  4529 
  4530 * a generic induction tactic `induct_tac' which works for all datatypes and
  4531 also for type `nat';
  4532 
  4533 * a generic case distinction tactic `exhaust_tac' which works for all
  4534 datatypes and also for type `nat';
  4535 
  4536 * each datatype comes with a function `size';
  4537 
  4538 * patterns in case expressions allow tuple patterns as arguments to
  4539 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  4540 
  4541 * primrec now also works with type nat;
  4542 
  4543 * recdef: a new declaration form, allows general recursive functions to be
  4544 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  4545 
  4546 * the constant for negation has been renamed from "not" to "Not" to
  4547 harmonize with FOL, ZF, LK, etc.;
  4548 
  4549 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  4550 infinite lists;
  4551 
  4552 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  4553 
  4554 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  4555 problems in commutative rings, using axiomatic type classes for + and *;
  4556 
  4557 * more examples in HOL/MiniML and HOL/Auth;
  4558 
  4559 * more default rewrite rules for quantifiers, union/intersection;
  4560 
  4561 * a new constant `arbitrary == @x.False';
  4562 
  4563 * HOLCF/IOA replaces old HOL/IOA;
  4564 
  4565 * HOLCF changes: derived all rules and arities
  4566   + axiomatic type classes instead of classes
  4567   + typedef instead of faking type definitions
  4568   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  4569   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  4570   + eliminated the types void, one, tr
  4571   + use unit lift and bool lift (with translations) instead of one and tr
  4572   + eliminated blift from Lift3.thy (use Def instead of blift)
  4573   all eliminated rules are derived as theorems --> no visible changes ;
  4574 
  4575 
  4576 *** ZF ***
  4577 
  4578 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  4579 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  4580 as ZF_cs addSIs [equalityI];
  4581 
  4582 
  4583 
  4584 New in Isabelle94-7 (November 96)
  4585 ---------------------------------
  4586 
  4587 * allowing negative levels (as offsets) in prlev and choplev;
  4588 
  4589 * super-linear speedup for large simplifications;
  4590 
  4591 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  4592 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  4593 FAIL); can suppress it using the command Delsimps (ex_simps @
  4594 all_simps); De Morgan laws are also now included, by default;
  4595 
  4596 * improved printing of ==>  :  ~:
  4597 
  4598 * new object-logic "Sequents" adds linear logic, while replacing LK
  4599 and Modal (thanks to Sara Kalvala);
  4600 
  4601 * HOL/Auth: correctness proofs for authentication protocols;
  4602 
  4603 * HOL: new auto_tac combines rewriting and classical reasoning (many
  4604 examples on HOL/Auth);
  4605 
  4606 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  4607 the rewriter and classical reasoner simultaneously;
  4608 
  4609 * function uresult no longer returns theorems in "standard" format;
  4610 regain previous version by: val uresult = standard o uresult;
  4611 
  4612 
  4613 
  4614 New in Isabelle94-6
  4615 -------------------
  4616 
  4617 * oracles -- these establish an interface between Isabelle and trusted
  4618 external reasoners, which may deliver results as theorems;
  4619 
  4620 * proof objects (in particular record all uses of oracles);
  4621 
  4622 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  4623 
  4624 * "constdefs" section in theory files;
  4625 
  4626 * "primrec" section (HOL) no longer requires names;
  4627 
  4628 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  4629 
  4630 
  4631 
  4632 New in Isabelle94-5
  4633 -------------------
  4634 
  4635 * reduced space requirements;
  4636 
  4637 * automatic HTML generation from theories;
  4638 
  4639 * theory files no longer require "..." (quotes) around most types;
  4640 
  4641 * new examples, including two proofs of the Church-Rosser theorem;
  4642 
  4643 * non-curried (1994) version of HOL is no longer distributed;
  4644 
  4645 
  4646 
  4647 New in Isabelle94-4
  4648 -------------------
  4649 
  4650 * greatly reduced space requirements;
  4651 
  4652 * theory files (.thy) no longer require \...\ escapes at line breaks;
  4653 
  4654 * searchable theorem database (see the section "Retrieving theorems" on
  4655 page 8 of the Reference Manual);
  4656 
  4657 * new examples, including Grabczewski's monumental case study of the
  4658 Axiom of Choice;
  4659 
  4660 * The previous version of HOL renamed to Old_HOL;
  4661 
  4662 * The new version of HOL (previously called CHOL) uses a curried syntax
  4663 for functions.  Application looks like f a b instead of f(a,b);
  4664 
  4665 * Mutually recursive inductive definitions finally work in HOL;
  4666 
  4667 * In ZF, pattern-matching on tuples is now available in all abstractions and
  4668 translates to the operator "split";
  4669 
  4670 
  4671 
  4672 New in Isabelle94-3
  4673 -------------------
  4674 
  4675 * new infix operator, addss, allowing the classical reasoner to
  4676 perform simplification at each step of its search.  Example:
  4677         fast_tac (cs addss ss)
  4678 
  4679 * a new logic, CHOL, the same as HOL, but with a curried syntax
  4680 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  4681 look like (a,b) instead of <a,b>;
  4682 
  4683 * PLEASE NOTE: CHOL will eventually replace HOL!
  4684 
  4685 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  4686 It translates to the operator "split".  A new theory of integers is available;
  4687 
  4688 * In ZF, integer numerals now denote two's-complement binary integers.
  4689 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  4690 
  4691 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  4692 of the Axiom of Choice;
  4693 
  4694 
  4695 
  4696 New in Isabelle94-2
  4697 -------------------
  4698 
  4699 * Significantly faster resolution;
  4700 
  4701 * the different sections in a .thy file can now be mixed and repeated
  4702 freely;
  4703 
  4704 * Database of theorems for FOL, HOL and ZF.  New
  4705 commands including qed, qed_goal and bind_thm store theorems in the database.
  4706 
  4707 * Simple database queries: return a named theorem (get_thm) or all theorems of
  4708 a given theory (thms_of), or find out what theory a theorem was proved in
  4709 (theory_of_thm);
  4710 
  4711 * Bugs fixed in the inductive definition and datatype packages;
  4712 
  4713 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  4714 and HOL_dup_cs obsolete;
  4715 
  4716 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  4717 have been removed;
  4718 
  4719 * Simpler definition of function space in ZF;
  4720 
  4721 * new results about cardinal and ordinal arithmetic in ZF;
  4722 
  4723 * 'subtype' facility in HOL for introducing new types as subsets of existing
  4724 types;
  4725 
  4726 
  4727 $Id$