NEWS
author haftmann
Fri Mar 09 08:45:50 2007 +0100 (2007-03-09)
changeset 22422 ee19cdb07528
parent 22384 33a46e6c7f04
child 22450 51ee032f9591
permissions -rw-r--r--
stepping towards uniform lattice theory development in HOL
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Theory syntax: the header format ``theory A = B + C:'' has been
    10 discontinued in favour of ``theory A imports B C begin''.  Use isatool
    11 fixheaders to convert existing theory files.  INCOMPATIBILITY.
    12 
    13 * Theory syntax: the old non-Isar theory file format has been
    14 discontinued altogether.  Note that ML proof scripts may still be used
    15 with Isar theories; migration is usually quite simple with the ML
    16 function use_legacy_bindings.  INCOMPATIBILITY.
    17 
    18 * Theory syntax: some popular names (e.g. "class", "fun", "help",
    19 "if") are now keywords.  INCOMPATIBILITY, use double quotes.
    20 
    21 * Legacy goal package: reduced interface to the bare minimum required
    22 to keep existing proof scripts running.  Most other user-level
    23 functions are now part of the OldGoals structure, which is *not* open
    24 by default (consider isatool expandshort before open OldGoals).
    25 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
    26 these tend to cause confusion about the actual goal (!) context being
    27 used here, which is not necessarily the same as the_context().
    28 
    29 * Command 'find_theorems': support "*" wildcard in "name:" criterion.
    30 
    31 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
    32 by default, which means that "prems" (and also "fixed variables") are
    33 suppressed from proof state output.  Note that the ProofGeneral
    34 settings mechanism allows to change and save options persistently, but
    35 older versions of Isabelle will fail to start up if a negative prems
    36 limit is imposed.
    37 
    38 * Local theory targets may be specified by non-nested blocks of
    39 ``context/locale/class ... begin'' followed by ``end''.  The body may
    40 contain definitions, theorems etc., including any derived mechanism
    41 that has been implemented on top of these primitives.  This concept
    42 generalizes the existing ``theorem (in ...)'' towards more versatility
    43 and scalability.
    44 
    45 * Proof General interface: proper undo of final 'end' command;
    46 discontinued Isabelle/classic mode (ML proof scripts).
    47 
    48 
    49 *** Document preparation ***
    50 
    51 * Added antiquotation @{theory name} which prints the given name,
    52 after checking that it refers to a valid ancestor theory in the
    53 current context.
    54 
    55 * Added antiquotations @{ML_type text} and @{ML_struct text} which
    56 check the given source text as ML type/structure, printing verbatim.
    57 
    58 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
    59 "c args == rhs" given in the current context.  (Any number of
    60 arguments may be given on the LHS.)
    61 
    62 
    63 
    64 *** Pure ***
    65 
    66 * class_package.ML offers a combination of axclasses and locales to
    67 achieve Haskell-like type classes in Isabelle. See
    68 HOL/ex/Classpackage.thy for examples.
    69 
    70 * Yet another code generator framework allows to generate executable
    71 code for ML and Haskell (including "class"es). A short usage sketch:
    72 
    73     internal compilation:
    74         code_gen <list of constants (term syntax)> (SML #)
    75     writing SML code to a file:
    76         code_gen <list of constants (term syntax)> (SML <filename>)
    77     writing Haskell code to a bunch of files:
    78         code_gen <list of constants (term syntax)> (Haskell <filename>)
    79 
    80 Reasonable default setup of framework in HOL/Main.
    81 
    82 Theorem attributs for selecting and transforming function equations theorems:
    83 
    84     [code fun]:       select a theorem as function equation for a specific constant
    85     [code nofun]:     deselect a theorem as function equation for a specific constant
    86     [code inline]:    select an equation theorem for unfolding (inlining) in place
    87     [code noinline]:  deselect an equation theorem for unfolding (inlining) in place
    88 
    89 User-defined serializations (target in {SML, Haskell}):
    90 
    91     code_const <and-list of constants (term syntax)>
    92       {(target) <and-list of const target syntax>}+
    93 
    94     code_type <and-list of type constructors>
    95       {(target) <and-list of type target syntax>}+
    96 
    97     code_instance <and-list of instances>
    98       {(target)}+
    99         where instance ::= <type constructor> :: <class>
   100 
   101     code_class <and_list of classes>
   102       {(target) <and-list of class target syntax>}+
   103         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
   104 
   105 For code_instance and code_class, target SML is silently ignored.
   106 
   107 See HOL theories and HOL/ex/Code*.thy for usage examples.  Doc/Isar/Advanced/Codegen/
   108 provides a tutorial.
   109 
   110 * Command 'no_translations' removes translation rules from theory
   111 syntax.
   112 
   113 * Overloaded definitions are now actually checked for acyclic
   114 dependencies.  The overloading scheme is slightly more general than
   115 that of Haskell98, although Isabelle does not demand an exact
   116 correspondence to type class and instance declarations.
   117 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
   118 exotic versions of overloading -- at the discretion of the user!
   119 
   120 Polymorphic constants are represented via type arguments, i.e. the
   121 instantiation that matches an instance against the most general
   122 declaration given in the signature.  For example, with the declaration
   123 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
   124 as c(nat).  Overloading is essentially simultaneous structural
   125 recursion over such type arguments.  Incomplete specification patterns
   126 impose global constraints on all occurrences, e.g. c('a * 'a) on the
   127 LHS means that more general c('a * 'b) will be disallowed on any RHS.
   128 Command 'print_theory' outputs the normalized system of recursive
   129 equations, see section "definitions".
   130 
   131 * Isar: improper proof element 'guess' is like 'obtain', but derives
   132 the obtained context from the course of reasoning!  For example:
   133 
   134   assume "EX x y. A x & B y"   -- "any previous fact"
   135   then guess x and y by clarify
   136 
   137 This technique is potentially adventurous, depending on the facts and
   138 proof tools being involved here.
   139 
   140 * Isar: known facts from the proof context may be specified as literal
   141 propositions, using ASCII back-quote syntax.  This works wherever
   142 named facts used to be allowed so far, in proof commands, proof
   143 methods, attributes etc.  Literal facts are retrieved from the context
   144 according to unification of type and term parameters.  For example,
   145 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
   146 theorems in the current context, then these are valid literal facts:
   147 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
   148 
   149 There is also a proof method "fact" which does the same composition
   150 for explicit goal states, e.g. the following proof texts coincide with
   151 certain special cases of literal facts:
   152 
   153   have "A" by fact                 ==  note `A`
   154   have "A ==> B" by fact           ==  note `A ==> B`
   155   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
   156   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
   157 
   158 * Isar: ":" (colon) is no longer a symbolic identifier character in
   159 outer syntax.  Thus symbolic identifiers may be used without
   160 additional white space in declarations like this: ``assume *: A''.
   161 
   162 * Isar: 'print_facts' prints all local facts of the current context,
   163 both named and unnamed ones.
   164 
   165 * Isar: 'def' now admits simultaneous definitions, e.g.:
   166 
   167   def x == "t" and y == "u"
   168 
   169 * Isar: added command 'unfolding', which is structurally similar to
   170 'using', but affects both the goal state and facts by unfolding given
   171 rewrite rules.  Thus many occurrences of the 'unfold' method or
   172 'unfolded' attribute may be replaced by first-class proof text.
   173 
   174 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
   175 and command 'unfolding' now all support object-level equalities
   176 (potentially conditional).  The underlying notion of rewrite rule is
   177 analogous to the 'rule_format' attribute, but *not* that of the
   178 Simplifier (which is usually more generous).
   179 
   180 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
   181 method expression within a sandbox consisting of the first N
   182 sub-goals, which need to exist.  For example, ``simp_all [3]''
   183 simplifies the first three sub-goals, while (rule foo, simp_all)[]
   184 simplifies all new goals that emerge from applying rule foo to the
   185 originally first one.
   186 
   187 * Isar: schematic goals are no longer restricted to higher-order
   188 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
   189 expected.
   190 
   191 * Isar: the conclusion of a long theorem statement is now either
   192 'shows' (a simultaneous conjunction, as before), or 'obtains'
   193 (essentially a disjunction of cases with local parameters and
   194 assumptions).  The latter allows to express general elimination rules
   195 adequately; in this notation common elimination rules look like this:
   196 
   197   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
   198     assumes "EX x. P x"
   199     obtains x where "P x"
   200 
   201   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
   202     assumes "A & B"
   203     obtains A and B
   204 
   205   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
   206     assumes "A | B"
   207     obtains
   208       A
   209     | B
   210 
   211 The subsequent classical rules even refer to the formal "thesis"
   212 explicitly:
   213 
   214   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
   215     obtains "~ thesis"
   216 
   217   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
   218     obtains "thesis ==> something"
   219 
   220 The actual proof of an 'obtains' statement is analogous to that of the
   221 Isar proof element 'obtain', only that there may be several cases.
   222 Optional case names may be specified in parentheses; these will be
   223 available both in the present proof and as annotations in the
   224 resulting rule, for later use with the 'cases' method (cf. attribute
   225 case_names).
   226 
   227 * Isar: the assumptions of a long theorem statement are available as
   228 "assms" fact in the proof context.  This is more appropriate than the
   229 (historical) "prems", which refers to all assumptions of the current
   230 context, including those from the target locale, proof body etc.
   231 
   232 * Isar: 'print_statement' prints theorems from the current theory or
   233 proof context in long statement form, according to the syntax of a
   234 top-level lemma.
   235 
   236 * Isar: 'obtain' takes an optional case name for the local context
   237 introduction rule (default "that").
   238 
   239 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
   240 explicit (is "_ ==> ?foo") in the rare cases where this still happens
   241 to occur.
   242 
   243 * Pure: syntax "CONST name" produces a fully internalized constant
   244 according to the current context.  This is particularly useful for
   245 syntax translations that should refer to internal constant
   246 representations independently of name spaces.
   247 
   248 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
   249 instead of "FOO ". This allows multiple binder declarations to coexist
   250 in the same context.  INCOMPATIBILITY.
   251 
   252 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
   253 primitive that also works in a locale context (both for constants and
   254 fixed variables).  Type declaration and internal syntactic
   255 representation of given constants retrieved from the context.
   256 
   257 * Isar/locales: new derived specification elements 'axiomatization',
   258 'definition', 'abbreviation', which support type-inference, admit
   259 object-level specifications (equality, equivalence).  See also the
   260 isar-ref manual.  Examples:
   261 
   262   axiomatization
   263     eq  (infix "===" 50) where
   264     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
   265 
   266   definition "f x y = x + y + 1"
   267   definition g where "g x = f x x"
   268 
   269   abbreviation
   270     neq  (infix "=!=" 50) where
   271     "x =!= y == ~ (x === y)"
   272 
   273 These specifications may be also used in a locale context.  Then the
   274 constants being introduced depend on certain fixed parameters, and the
   275 constant name is qualified by the locale base name.  An internal
   276 abbreviation takes care for convenient input and output, making the
   277 parameters implicit and using the original short name.  See also
   278 HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
   279 entities from a monomorphic theory.
   280 
   281 Presently, abbreviations are only available 'in' a target locale, but
   282 not inherited by general import expressions.  Also note that
   283 'abbreviation' may be used as a type-safe replacement for 'syntax' +
   284 'translations' in common applications.
   285 
   286 Concrete syntax is attached to specified constants in internal form,
   287 independently of name spaces.  The parse tree representation is
   288 slightly different -- use 'notation' instead of raw 'syntax', and
   289 'translations' with explicit "CONST" markup to accommodate this.
   290 
   291 * Pure: command 'print_abbrevs' prints all constant abbreviations of
   292 the current context.  Print mode "no_abbrevs" prevents inversion of
   293 abbreviations on output.
   294 
   295 * Isar/locales: improved parameter handling:
   296 - use of locales "var" and "struct" no longer necessary;
   297 - parameter renamings are no longer required to be injective.
   298   This enables, for example, to define a locale for endomorphisms thus:
   299   locale endom = homom mult mult h.
   300 
   301 * Isar/locales: changed the way locales with predicates are defined.
   302 Instead of accumulating the specification, the imported expression is
   303 now an interpretation.  INCOMPATIBILITY: different normal form of
   304 locale expressions.  In particular, in interpretations of locales with
   305 predicates, goals repesenting already interpreted fragments are not
   306 removed automatically.  Use methods `intro_locales' and
   307 `unfold_locales'; see below.
   308 
   309 * Isar/locales: new methods `intro_locales' and `unfold_locales'
   310 provide backward reasoning on locales predicates.  The methods are
   311 aware of interpretations and discharge corresponding goals.
   312 `intro_locales' is less aggressive then `unfold_locales' and does not
   313 unfold predicates to assumptions.
   314 
   315 * Isar/locales: the order in which locale fragments are accumulated
   316 has changed.  This enables to override declarations from fragments due
   317 to interpretations -- for example, unwanted simp rules.
   318 
   319 * Provers/induct: improved internal context management to support
   320 local fixes and defines on-the-fly.  Thus explicit meta-level
   321 connectives !! and ==> are rarely required anymore in inductive goals
   322 (using object-logic connectives for this purpose has been long
   323 obsolete anyway).  The subsequent proof patterns illustrate advanced
   324 techniques of natural induction; general datatypes and inductive sets
   325 work analogously (see also src/HOL/Lambda for realistic examples).
   326 
   327 (1) This is how to ``strengthen'' an inductive goal wrt. certain
   328 parameters:
   329 
   330   lemma
   331     fixes n :: nat and x :: 'a
   332     assumes a: "A n x"
   333     shows "P n x"
   334     using a                     -- {* make induct insert fact a *}
   335   proof (induct n arbitrary: x) -- {* generalize goal to "!!x. A n x ==> P n x" *}
   336     case 0
   337     show ?case sorry
   338   next
   339     case (Suc n)
   340     note `!!x. A n x ==> P n x` -- {* induction hypothesis, according to induction rule *}
   341     note `A (Suc n) x`          -- {* induction premise, stemming from fact a *}
   342     show ?case sorry
   343   qed
   344 
   345 (2) This is how to perform induction over ``expressions of a certain
   346 form'', using a locally defined inductive parameter n == "a x"
   347 together with strengthening (the latter is usually required to get
   348 sufficiently flexible induction hypotheses):
   349 
   350   lemma
   351     fixes a :: "'a => nat"
   352     assumes a: "A (a x)"
   353     shows "P (a x)"
   354     using a
   355   proof (induct n == "a x" arbitrary: x)
   356     ...
   357 
   358 See also HOL/Isar_examples/Puzzle.thy for an application of the this
   359 particular technique.
   360 
   361 (3) This is how to perform existential reasoning ('obtains' or
   362 'obtain') by induction, while avoiding explicit object-logic
   363 encodings:
   364 
   365   lemma
   366     fixes n :: nat
   367     obtains x :: 'a where "P n x" and "Q n x"
   368   proof (induct n arbitrary: thesis)
   369     case 0
   370     obtain x where "P 0 x" and "Q 0 x" sorry
   371     then show thesis by (rule 0)
   372   next
   373     case (Suc n)
   374     obtain x where "P n x" and "Q n x" by (rule Suc.hyps)
   375     obtain x where "P (Suc n) x" and "Q (Suc n) x" sorry
   376     then show thesis by (rule Suc.prems)
   377   qed
   378 
   379 Here the 'arbitrary: thesis' specification essentially modifies the
   380 scope of the formal thesis parameter, in order to the get the whole
   381 existence statement through the induction as expected.
   382 
   383 * Provers/induct: mutual induction rules are now specified as a list
   384 of rule sharing the same induction cases.  HOL packages usually
   385 provide foo_bar.inducts for mutually defined items foo and bar
   386 (e.g. inductive sets or datatypes).  INCOMPATIBILITY, users need to
   387 specify mutual induction rules differently, i.e. like this:
   388 
   389   (induct rule: foo_bar.inducts)
   390   (induct set: foo bar)
   391   (induct type: foo bar)
   392 
   393 The ML function ProjectRule.projections turns old-style rules into the
   394 new format.
   395 
   396 * Provers/induct: improved handling of simultaneous goals.  Instead of
   397 introducing object-level conjunction, the statement is now split into
   398 several conclusions, while the corresponding symbolic cases are
   399 nested accordingly.  INCOMPATIBILITY, proofs need to be structured
   400 explicitly.  For example:
   401 
   402   lemma
   403     fixes n :: nat
   404     shows "P n" and "Q n"
   405   proof (induct n)
   406     case 0 case 1
   407     show "P 0" sorry
   408   next
   409     case 0 case 2
   410     show "Q 0" sorry
   411   next
   412     case (Suc n) case 1
   413     note `P n` and `Q n`
   414     show "P (Suc n)" sorry
   415   next
   416     case (Suc n) case 2
   417     note `P n` and `Q n`
   418     show "Q (Suc n)" sorry
   419   qed
   420 
   421 The split into subcases may be deferred as follows -- this is
   422 particularly relevant for goal statements with local premises.
   423 
   424   lemma
   425     fixes n :: nat
   426     shows "A n ==> P n" and "B n ==> Q n"
   427   proof (induct n)
   428     case 0
   429     {
   430       case 1
   431       note `A 0`
   432       show "P 0" sorry
   433     next
   434       case 2
   435       note `B 0`
   436       show "Q 0" sorry
   437     }
   438   next
   439     case (Suc n)
   440     note `A n ==> P n` and `B n ==> Q n`
   441     {
   442       case 1
   443       note `A (Suc n)`
   444       show "P (Suc n)" sorry
   445     next
   446       case 2
   447       note `B (Suc n)`
   448       show "Q (Suc n)" sorry
   449     }
   450   qed
   451 
   452 If simultaneous goals are to be used with mutual rules, the statement
   453 needs to be structured carefully as a two-level conjunction, using
   454 lists of propositions separated by 'and':
   455 
   456   lemma
   457     shows "a : A ==> P1 a"
   458           "a : A ==> P2 a"
   459       and "b : B ==> Q1 b"
   460           "b : B ==> Q2 b"
   461           "b : B ==> Q3 b"
   462   proof (induct set: A B)
   463 
   464 * Provers/induct: support coinduction as well.  See
   465 src/HOL/Library/Coinductive_List.thy for various examples.
   466 
   467 * Attribute "symmetric" produces result with standardized schematic
   468 variables (index 0).  Potential INCOMPATIBILITY.
   469 
   470 * Simplifier: by default the simplifier trace only shows top level
   471 rewrites now. That is, trace_simp_depth_limit is set to 1 by
   472 default. Thus there is less danger of being flooded by the trace. The
   473 trace indicates where parts have been suppressed.
   474   
   475 * Provers/classical: removed obsolete classical version of elim_format
   476 attribute; classical elim/dest rules are now treated uniformly when
   477 manipulating the claset.
   478 
   479 * Provers/classical: stricter checks to ensure that supplied intro,
   480 dest and elim rules are well-formed; dest and elim rules must have at
   481 least one premise.
   482 
   483 * Provers/classical: attributes dest/elim/intro take an optional
   484 weight argument for the rule (just as the Pure versions).  Weights are
   485 ignored by automated tools, but determine the search order of single
   486 rule steps.
   487 
   488 * Syntax: input syntax now supports dummy variable binding "%_. b",
   489 where the body does not mention the bound variable.  Note that dummy
   490 patterns implicitly depend on their context of bounds, which makes
   491 "{_. _}" match any set comprehension as expected.  Potential
   492 INCOMPATIBILITY -- parse translations need to cope with syntactic
   493 constant "_idtdummy" in the binding position.
   494 
   495 * Syntax: removed obsolete syntactic constant "_K" and its associated
   496 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
   497 for example "A -> B" => "Pi A (%_. B)".
   498 
   499 * Pure: 'class_deps' command visualizes the subclass relation, using
   500 the graph browser tool.
   501 
   502 * Pure: 'print_theory' now suppresses entities with internal name
   503 (trailing "_") by default; use '!' option for full details.
   504 
   505 
   506 *** HOL ***
   507 
   508 * Some steps towards more uniform lattice theory development in HOL.  Obvious changes:
   509 
   510     constants "meet" and "join" now named "inf" and "sup"
   511     constant "Meet" now named "Inf"
   512 
   513   theorem renames:
   514     meet_left_le            ~> inf_le1
   515     meet_right_le           ~> inf_le2
   516     join_left_le            ~> sup_ge1
   517     join_right_le           ~> sup_ge2
   518     meet_join_le            ~> inf_sup_ord
   519     le_meetI                ~> le_infI
   520     join_leI                ~> le_supI
   521     le_meet                 ~> le_inf_iff
   522     le_join                 ~> ge_sup_conv
   523     meet_idempotent         ~> inf_idem
   524     join_idempotent         ~> sup_idem
   525     meet_comm               ~> inf_commute
   526     join_comm               ~> sup_commute
   527     meet_leI1               ~> le_infI1
   528     meet_leI2               ~> le_infI2
   529     le_joinI1               ~> le_supI1
   530     le_joinI2               ~> le_supI2
   531     meet_assoc              ~> inf_assoc
   532     join_assoc              ~> sup_assoc
   533     meet_left_comm          ~> inf_left_commute
   534     meet_left_idempotent    ~> inf_left_idem
   535     join_left_comm          ~> sup_left_commute
   536     join_left_idempotent    ~> sup_left_idem
   537     meet_aci                ~> inf_aci
   538     join_aci                ~> sup_aci
   539     le_def_meet             ~> le_iff_inf
   540     le_def_join             ~> le_iff_sup
   541     join_absorp2            ~> sup_absorb2
   542     join_absorp1            ~> sup_absorb1
   543     meet_absorp1            ~> inf_absorb1
   544     meet_absorp2            ~> inf_absorb2
   545     meet_join_absorp        ~> inf_sup_absorb
   546     join_meet_absorp        ~> sup_inf_absorb
   547     distrib_join_le         ~> distrib_sup_le
   548     distrib_meet_le         ~> distrib_inf_le
   549 
   550     add_meet_distrib_left   ~> add_inf_distrib_left
   551     add_join_distrib_left   ~> add_sup_distrib_left
   552     is_join_neg_meet        ~> is_join_neg_inf
   553     is_meet_neg_join        ~> is_meet_neg_sup
   554     add_meet_distrib_right  ~> add_inf_distrib_right
   555     add_join_distrib_right  ~> add_sup_distrib_right
   556     add_meet_join_distribs  ~> add_sup_inf_distribs
   557     join_eq_neg_meet        ~> sup_eq_neg_inf
   558     meet_eq_neg_join        ~> inf_eq_neg_sup
   559     add_eq_meet_join        ~> add_eq_inf_sup
   560     meet_0_imp_0            ~> inf_0_imp_0
   561     join_0_imp_0            ~> sup_0_imp_0
   562     meet_0_eq_0             ~> inf_0_eq_0
   563     join_0_eq_0             ~> sup_0_eq_0
   564     neg_meet_eq_join        ~> neg_inf_eq_sup
   565     neg_join_eq_meet        ~> neg_sup_eq_inf
   566     join_eq_if              ~> sup_eq_if
   567 
   568     mono_meet               ~> mono_inf
   569     mono_join               ~> mono_sup
   570     meet_bool_eq            ~> inf_bool_eq
   571     join_bool_eq            ~> sup_bool_eq
   572     meet_fun_eq             ~> inf_fun_eq
   573     join_fun_eq             ~> sup_fun_eq
   574     meet_set_eq             ~> inf_set_eq
   575     join_set_eq             ~> sup_set_eq
   576     meet1_iff               ~> inf1_iff
   577     meet2_iff               ~> inf2_iff
   578     meet1I                  ~> inf1I
   579     meet2I                  ~> inf2I
   580     meet1D1                 ~> inf1D1
   581     meet2D1                 ~> inf2D1
   582     meet1D2                 ~> inf1D2
   583     meet2D2                 ~> inf2D2
   584     meet1E                  ~> inf1E
   585     meet2E                  ~> inf2E
   586     join1_iff               ~> sup1_iff
   587     join2_iff               ~> sup2_iff
   588     join1I1                 ~> sup1I1
   589     join2I1                 ~> sup2I1
   590     join1I1                 ~> sup1I1
   591     join2I2                 ~> sup1I2
   592     join1CI                 ~> sup1CI
   593     join2CI                 ~> sup2CI
   594     join1E                  ~> sup1E
   595     join2E                  ~> sup2E
   596 
   597     is_meet_Meet            ~> is_meet_Inf
   598     Meet_bool_def           ~> Inf_bool_def
   599     Meet_fun_def            ~> Inf_fun_def
   600     Meet_greatest           ~> Inf_greatest
   601     Meet_lower              ~> Inf_lower
   602     Meet_set_def            ~> Inf_set_def
   603 
   604     listsp_meetI            ~> listsp_infI
   605     listsp_meet_eq          ~> listsp_inf_eq
   606 
   607 * Class (axclass + locale) "preorder" and "linear": facts "refl", "trans" and
   608 "cases" renamed ro "order_refl", "order_trans" and "linorder_cases", to
   609 avoid clashes with HOL "refl" and "trans". INCOMPATIBILITY.
   610 
   611 * Addes class (axclass + locale) "preorder" as superclass of "order";
   612 potential INCOMPATIBILITY: order of proof goals in order/linorder instance
   613 proofs changed.
   614 
   615 * Dropped lemma duplicate def_imp_eq in favor of meta_eq_to_obj_eq.
   616 INCOMPATIBILITY.
   617 
   618 * Dropped lemma duplicate if_def2 in favor of if_bool_eq_conj.
   619 INCOMPATIBILITY.
   620 
   621 * Added syntactic class "size"; overloaded constant "size" now has
   622 type "'a::size ==> bool"
   623 
   624 * Renamed constants "Divides.op div", "Divides.op mod" and "Divides.op
   625 dvd" to "Divides.div", "Divides.mod" and "Divides.dvd". INCOMPATIBILITY.
   626 
   627 * Added method "lexicographic_order" automatically synthesizes
   628 termination relations as lexicographic combinations of size measures
   629 -- 'function' package.
   630 
   631 * HOL/records: generalised field-update to take a function on the
   632 field rather than the new value: r(|A := x|) is translated to A_update
   633 (K x) r The K-combinator that is internally used is called K_record.
   634 INCOMPATIBILITY: Usage of the plain update functions has to be
   635 adapted.
   636  
   637 * axclass "semiring_0" now contains annihilation axioms x * 0 = 0 and
   638 0 * x = 0, which are required for a semiring.  Richer structures do
   639 not inherit from semiring_0 anymore, because this property is a
   640 theorem there, not an axiom.  INCOMPATIBILITY: In instances of
   641 semiring_0, there is more to prove, but this is mostly trivial.
   642 
   643 * axclass "recpower" was generalized to arbitrary monoids, not just
   644 commutative semirings.  INCOMPATIBILITY: If you use recpower and need
   645 commutativity or a semiring property, add the corresponding classes.
   646 
   647 * Unified locale partial_order with class definition (cf. theory
   648 Orderings), added parameter ``less''.  INCOMPATIBILITY.
   649 
   650 * Constant "List.list_all2" in List.thy now uses authentic syntax.
   651 INCOMPATIBILITY: translations containing list_all2 may go wrong.  On
   652 Isar level, use abbreviations instead.
   653 
   654 * Renamed constant "List.op mem" to "List.memberl" INCOMPATIBILITY:
   655 rarely occuring name references (e.g. ``List.op mem.simps'') require
   656 renaming (e.g. ``List.memberl.simps'').
   657 
   658 * Renamed constants "0" to "HOL.zero" and "1" to "HOL.one".
   659 INCOMPATIBILITY.
   660 
   661 * Added theory Code_Generator providing class 'eq', allowing for code
   662 generation with polymorphic equality.
   663 
   664 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
   665 been abandoned in favour of plain 'int'. INCOMPATIBILITY --
   666 significant changes for setting up numeral syntax for types:
   667 
   668   - new constants Numeral.pred and Numeral.succ instead
   669       of former Numeral.bin_pred and Numeral.bin_succ.
   670   - Use integer operations instead of bin_add, bin_mult and so on.
   671   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
   672   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
   673 
   674 See HOL/Integ/IntArith.thy for an example setup.
   675 
   676 * New top level command 'normal_form' computes the normal form of a
   677 term that may contain free variables. For example ``normal_form
   678 "rev[a,b,c]"'' produces ``[b,c,a]'' (without proof).  This command is
   679 suitable for heavy-duty computations because the functions are
   680 compiled to ML first.
   681 
   682 * Alternative iff syntax "A <-> B" for equality on bool (with priority
   683 25 like -->); output depends on the "iff" print_mode, the default is
   684 "A = B" (with priority 50).
   685 
   686 * Renamed constants in HOL.thy and Orderings.thy:
   687     op +   ~> HOL.plus
   688     op -   ~> HOL.minus
   689     uminus ~> HOL.uminus
   690     op *   ~> HOL.times
   691     op <   ~> Orderings.less
   692     op <=  ~> Orderings.less_eq
   693 
   694 Adaptions may be required in the following cases:
   695 
   696 a) User-defined constants using any of the names "plus", "minus", "times",
   697 "less" or "less_eq". The standard syntax translations for "+", "-" and "*"
   698 may go wrong.
   699 INCOMPATIBILITY: use more specific names.
   700 
   701 b) Variables named "plus", "minus", "times", "less", "less_eq"
   702 INCOMPATIBILITY: use more specific names.
   703 
   704 c) Permutative equations (e.g. "a + b = b + a")
   705 Since the change of names also changes the order of terms, permutative
   706 rewrite rules may get applied in a different order. Experience shows that
   707 this is rarely the case (only two adaptions in the whole Isabelle
   708 distribution).
   709 INCOMPATIBILITY: rewrite proofs
   710 
   711 d) ML code directly refering to constant names
   712 This in general only affects hand-written proof tactics, simprocs and so on.
   713 INCOMPATIBILITY: grep your sourcecode and replace names.
   714 
   715 * Relations less (<) and less_eq (<=) are also available on type bool.
   716 Modified syntax to disallow nesting without explicit parentheses,
   717 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".
   718 
   719 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
   720 
   721 * Relation composition operator "op O" now has precedence 75 and binds
   722 stronger than union and intersection. INCOMPATIBILITY.
   723 
   724 * The old set interval syntax "{m..n(}" (and relatives) has been
   725 removed.  Use "{m..<n}" (and relatives) instead.
   726 
   727 * In the context of the assumption "~(s = t)" the Simplifier rewrites
   728 "t = s" to False (by simproc "neq_simproc").  For backward
   729 compatibility this can be disabled by ML "reset use_neq_simproc".
   730 
   731 * "m dvd n" where m and n are numbers is evaluated to True/False by
   732 simp.
   733 
   734 * Theorem Cons_eq_map_conv no longer declared as ``simp''.
   735 
   736 * Theorem setsum_mult renamed to setsum_right_distrib.
   737 
   738 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
   739 ``rule'' method.
   740 
   741 * Reimplemented methods ``sat'' and ``satx'', with several
   742 improvements: goals no longer need to be stated as "<prems> ==>
   743 False", equivalences (i.e. "=" on type bool) are handled, variable
   744 names of the form "lit_<n>" are no longer reserved, significant
   745 speedup.
   746 
   747 * Methods ``sat'' and ``satx'' can now replay MiniSat proof traces.
   748 zChaff is still supported as well.
   749 
   750 * 'inductive' and 'datatype': provide projections of mutual rules,
   751 bundled as foo_bar.inducts;
   752 
   753 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
   754 Library.
   755 
   756 * Library: moved theory Accessible_Part to main HOL.
   757 
   758 * Library: added theory Coinductive_List of potentially infinite lists
   759 as greatest fixed-point.
   760 
   761 * Library: added theory AssocList which implements (finite) maps as
   762 association lists.
   763 
   764 * Added proof method ``evaluation'' for efficiently solving a goal
   765 (i.e. a boolean expression) by compiling it to ML. The goal is
   766 "proved" (via an oracle) if it evaluates to True.
   767 
   768 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
   769 also when invoked by the simplifier.  This results in the simplifier
   770 being more powerful on arithmetic goals.  INCOMPATIBILITY.  Set
   771 fast_arith_split_limit to 0 to obtain the old behavior.
   772 
   773 * Support for hex (0x20) and binary (0b1001) numerals.
   774 
   775 * New method: reify eqs (t), where eqs are equations for an
   776 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
   777 parameter, computes a term s::'b and a list xs::'a list and proves the
   778 theorem I xs s = t. This is also known as reification or quoting. The
   779 resulting theorem is applied to the subgoal to substitute t with I xs
   780 s.  If t is omitted, the subgoal itself is reified.
   781 
   782 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
   783 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
   784 where f is supposed to be a computable function (in the sense of code
   785 generattion). The method uses reify to compute s and xs as above then
   786 applies corr_thm and uses normalization by evaluation to "prove" f s =
   787 r and finally gets the theorem t = r, which is again applied to the
   788 subgoal. An Example is available in HOL/ex/ReflectionEx.thy.
   789 
   790 * Reflection: Automatic refification now handels binding, an example
   791 is available in HOL/ex/ReflectionEx.thy
   792 
   793 
   794 *** HOL-Algebra ***
   795 
   796 * Formalisation of ideals and the quotient construction over rings.
   797 
   798 * Order and lattice theory no longer based on records.
   799 INCOMPATIBILITY.
   800 
   801 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
   802 greatest_closed.  INCOMPATIBILITY.
   803 
   804 * Method algebra is now set up via an attribute.  For examples see
   805 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
   806 of algebraic structures.
   807 
   808 * Renamed theory CRing to Ring.
   809 
   810 
   811 *** HOL-Complex ***
   812 
   813 * Theory Real: new method ferrack implements quantifier elimination
   814 for linear arithmetic over the reals. The quantifier elimination
   815 feature is used only for decision, for compatibility with arith. This
   816 means a goal is either solved or left unchanged, no simplification.
   817 
   818 * Real: New axiomatic classes formalize real normed vector spaces and
   819 algebras, using new overloaded constants scaleR :: real => 'a => 'a
   820 and norm :: 'a => real.
   821 
   822 * Real: New constant of_real :: real => 'a::real_algebra_1 injects
   823 from reals into other types. The overloaded constant Reals :: 'a set
   824 is now defined as range of_real; potential INCOMPATIBILITY.
   825 
   826 * Hyperreal: Several constants that previously worked only for the
   827 reals have been generalized, so they now work over arbitrary vector
   828 spaces. Type annotations may need to be added in some cases; potential
   829 INCOMPATIBILITY.
   830 
   831   Infinitesimal  :: ('a::real_normed_vector) star set"
   832   HFinite        :: ('a::real_normed_vector) star set"
   833   HInfinite      :: ('a::real_normed_vector) star set"
   834   approx         :: ('a::real_normed_vector) star => 'a star => bool
   835   monad          :: ('a::real_normed_vector) star => 'a star set
   836   galaxy         :: ('a::real_normed_vector) star => 'a star set
   837   (NS)LIMSEQ     :: [nat, 'a::real_normed_vector, 'a] => bool
   838   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
   839   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
   840   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
   841   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
   842   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
   843   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
   844 
   845 * Complex: Some complex-specific constants are now abbreviations for
   846 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
   847 hnorm.  Other constants have been entirely removed in favor of the
   848 polymorphic versions (INCOMPATIBILITY):
   849 
   850   approx        <-- capprox
   851   HFinite       <-- CFinite
   852   HInfinite     <-- CInfinite
   853   Infinitesimal <-- CInfinitesimal
   854   monad         <-- cmonad
   855   galaxy        <-- cgalaxy
   856   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
   857   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
   858   (ns)deriv     <-- (ns)cderiv
   859 
   860 
   861 *** ML ***
   862 
   863 * ML within Isar: antiquotations allow to embed statically-checked
   864 formal entities in the source, referring to the context available at
   865 compile-time.  For example:
   866 
   867 ML {* @{typ "'a => 'b"} *}
   868 ML {* @{term "%x. x"} *}
   869 ML {* @{prop "x == y"} *}
   870 ML {* @{ctyp "'a => 'b"} *}
   871 ML {* @{cterm "%x. x"} *}
   872 ML {* @{cprop "x == y"} *}
   873 ML {* @{thm asm_rl} *}
   874 ML {* @{thms asm_rl} *}
   875 ML {* @{const_name c} *}
   876 ML {* @{const_syntax c} *}
   877 ML {* @{context} *}
   878 ML {* @{theory} *}
   879 ML {* @{theory Pure} *}
   880 ML {* @{simpset} *}
   881 ML {* @{claset} *}
   882 ML {* @{clasimpset} *}
   883 
   884 The same works for sources being ``used'' within an Isar context.
   885 
   886 * ML in Isar: improved error reporting; extra verbosity with
   887 Toplevel.debug enabled.
   888 
   889 * Pure/library:
   890 
   891   val burrow: ('a list -> 'b list) -> 'a list list -> 'b list list
   892   val fold_burrow: ('a list -> 'c -> 'b list * 'd) -> 'a list list -> 'c -> 'b list list * 'd
   893 
   894 The semantics of "burrow" is: "take a function with *simulatanously*
   895 transforms a list of value, and apply it *simulatanously* to a list of
   896 list of values of the appropriate type". Compare this with "map" which
   897 would *not* apply its argument function simulatanously but in
   898 sequence; "fold_burrow" has an additional context.
   899 
   900 * Pure/library: functions map2 and fold2 with curried syntax for
   901 simultanous mapping and folding:
   902 
   903     val map2: ('a -> 'b -> 'c) -> 'a list -> 'b list -> 'c list
   904     val fold2: ('a -> 'b -> 'c -> 'c) -> 'a list -> 'b list -> 'c -> 'c
   905 
   906 * Pure/library: indexed lists - some functions in the Isabelle library
   907 treating lists over 'a as finite mappings from [0...n] to 'a have been
   908 given more convenient names and signatures reminiscent of similar
   909 functions for alists, tables, etc:
   910 
   911   val nth: 'a list -> int -> 'a 
   912   val nth_map: int -> ('a -> 'a) -> 'a list -> 'a list
   913   val fold_index: (int * 'a -> 'b -> 'b) -> 'a list -> 'b -> 'b
   914 
   915 Note that fold_index starts counting at index 0, not 1 like foldln
   916 used to.
   917 
   918 * Pure/library: added general ``divide_and_conquer'' combinator on
   919 lists.
   920 
   921 * Pure/General/table.ML: the join operations now works via exceptions
   922 DUP/SAME instead of type option.  This is simpler in simple cases, and
   923 admits slightly more efficient complex applications.
   924 
   925 * Pure: datatype Context.generic joins theory/Proof.context and
   926 provides some facilities for code that works in either kind of
   927 context, notably GenericDataFun for uniform theory and proof data.
   928 
   929 * Pure: 'advanced' translation functions (parse_translation etc.) now
   930 use Context.generic instead of just theory.
   931 
   932 * Pure: simplified internal attribute type, which is now always
   933 Context.generic * thm -> Context.generic * thm.  Global (theory)
   934 vs. local (Proof.context) attributes have been discontinued, while
   935 minimizing code duplication.  Thm.rule_attribute and
   936 Thm.declaration_attribute build canonical attributes; see also
   937 structure Context for further operations on Context.generic, notably
   938 GenericDataFun.  INCOMPATIBILITY, need to adapt attribute type
   939 declarations and definitions.
   940 
   941 * Pure/kernel: consts certification ignores sort constraints given in
   942 signature declarations.  (This information is not relevant to the
   943 logic, but only for type inference.)  IMPORTANT INTERNAL CHANGE,
   944 potential INCOMPATIBILITY.
   945 
   946 * Pure: axiomatic type classes are now purely definitional, with
   947 explicit proofs of class axioms and super class relations performed
   948 internally.  See Pure/axclass.ML for the main internal interfaces --
   949 notably AxClass.define_class supercedes AxClass.add_axclass, and
   950 AxClass.axiomatize_class/classrel/arity supercede
   951 Sign.add_classes/classrel/arities.
   952 
   953 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
   954 global/local versions on theory vs. Proof.context have been
   955 discontinued; Attrib.syntax and Method.syntax have been adapted
   956 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
   957 attributes, methods, etc.
   958 
   959 * Pure: several functions of signature "... -> theory -> theory * ..."
   960 have been reoriented to "... -> theory -> ... * theory" in order to
   961 allow natural usage in combination with the ||>, ||>>, |-> and
   962 fold_map combinators.
   963 
   964 * Pure: official theorem names (closed derivations) and additional
   965 comments (tags) are now strictly separate.  Name hints -- which are
   966 maintained as tags -- may be attached any time without affecting the
   967 derivation.
   968 
   969 * Pure: primitive rule lift_rule now takes goal cterm instead of an
   970 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
   971 achieve the old behaviour.
   972 
   973 * Pure: the "Goal" constant is now called "prop", supporting a
   974 slightly more general idea of ``protecting'' meta-level rule
   975 statements.
   976 
   977 * Pure: Logic.(un)varify only works in a global context, which is now
   978 enforced instead of silently assumed.  INCOMPATIBILITY, may use
   979 Logic.legacy_(un)varify as temporary workaround.
   980 
   981 * Pure: structure Name provides scalable operations for generating
   982 internal variable names, notably Name.variants etc.  This replaces
   983 some popular functions from term.ML:
   984 
   985   Term.variant		->  Name.variant
   986   Term.variantlist	->  Name.variant_list  (*canonical argument order*)
   987   Term.invent_names	->  Name.invent_list
   988 
   989 Note that low-level renaming rarely occurs in new code -- operations
   990 from structure Variable are used instead (see below).
   991 
   992 * Pure: structure Variable provides fundamental operations for proper
   993 treatment of fixed/schematic variables in a context.  For example,
   994 Variable.import introduces fixes for schematics of given facts and
   995 Variable.export reverses the effect (up to renaming) -- this replaces
   996 various freeze_thaw operations.
   997 
   998 * Pure: structure Goal provides simple interfaces for
   999 init/conclude/finish and tactical prove operations (replacing former
  1000 Tactic.prove).  Goal.prove is the canonical way to prove results
  1001 within a given context; Goal.prove_global is a degraded version for
  1002 theory level goals, including a global Drule.standard.  Note that
  1003 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  1004 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  1005 in a locale context).
  1006 
  1007 * Isar: simplified treatment of user-level errors, using exception
  1008 ERROR of string uniformly.  Function error now merely raises ERROR,
  1009 without any side effect on output channels.  The Isar toplevel takes
  1010 care of proper display of ERROR exceptions.  ML code may use plain
  1011 handle/can/try; cat_error may be used to concatenate errors like this:
  1012 
  1013   ... handle ERROR msg => cat_error msg "..."
  1014 
  1015 Toplevel ML code (run directly or through the Isar toplevel) may be
  1016 embedded into the Isar toplevel with exception display/debug like
  1017 this:
  1018 
  1019   Isar.toplevel (fn () => ...)
  1020 
  1021 INCOMPATIBILITY, removed special transform_error facilities, removed
  1022 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  1023 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  1024 -- use plain ERROR instead.
  1025 
  1026 * Isar: theory setup now has type (theory -> theory), instead of a
  1027 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  1028 
  1029 * Isar: installed ML toplevel pretty printer for type Proof.context,
  1030 subject to ProofContext.debug/verbose flags.
  1031 
  1032 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  1033 theory before entering a proof state.  Transactions now always see a
  1034 quasi-functional intermediate checkpoint, both in interactive and
  1035 batch mode.
  1036 
  1037 * Simplifier: the simpset of a running simplification process now
  1038 contains a proof context (cf. Simplifier.the_context), which is the
  1039 very context that the initial simpset has been retrieved from (by
  1040 simpset_of/local_simpset_of).  Consequently, all plug-in components
  1041 (solver, looper etc.) may depend on arbitrary proof data.
  1042 
  1043 * Simplifier.inherit_context inherits the proof context (plus the
  1044 local bounds) of the current simplification process; any simproc
  1045 etc. that calls the Simplifier recursively should do this!  Removed
  1046 former Simplifier.inherit_bounds, which is already included here --
  1047 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  1048 specify an explicit context using Simplifier.context/theory_context.
  1049 
  1050 * Simplifier/Classical Reasoner: more abstract interfaces
  1051 change_simpset/claset for modifying the simpset/claset reference of a
  1052 theory; raw versions simpset/claset_ref etc. have been discontinued --
  1053 INCOMPATIBILITY.
  1054 
  1055 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  1056 "Trueprop" etc.
  1057 
  1058 
  1059 *** System ***
  1060 
  1061 * settings: ML_IDENTIFIER -- which is appended to user specific heap
  1062 locations -- now includes the Isabelle version identifier as well.
  1063 This simplifies use of multiple Isabelle installations.
  1064 
  1065 * isabelle-process: option -S (secure mode) disables some critical
  1066 operations, notably runtime compilation and evaluation of ML source
  1067 code.
  1068 
  1069 
  1070 New in Isabelle2005 (October 2005)
  1071 ----------------------------------
  1072 
  1073 *** General ***
  1074 
  1075 * Theory headers: the new header syntax for Isar theories is
  1076 
  1077   theory <name>
  1078   imports <theory1> ... <theoryN>
  1079   uses <file1> ... <fileM>
  1080   begin
  1081 
  1082 where the 'uses' part is optional.  The previous syntax
  1083 
  1084   theory <name> = <theory1> + ... + <theoryN>:
  1085 
  1086 will disappear in the next release.  Use isatool fixheaders to convert
  1087 existing theory files.  Note that there is no change in ancient
  1088 non-Isar theories now, but these will disappear soon.
  1089 
  1090 * Theory loader: parent theories can now also be referred to via
  1091 relative and absolute paths.
  1092 
  1093 * Command 'find_theorems' searches for a list of criteria instead of a
  1094 list of constants. Known criteria are: intro, elim, dest, name:string,
  1095 simp:term, and any term. Criteria can be preceded by '-' to select
  1096 theorems that do not match. Intro, elim, dest select theorems that
  1097 match the current goal, name:s selects theorems whose fully qualified
  1098 name contain s, and simp:term selects all simplification rules whose
  1099 lhs match term.  Any other term is interpreted as pattern and selects
  1100 all theorems matching the pattern. Available in ProofGeneral under
  1101 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  1102 
  1103   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  1104 
  1105 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  1106 matching the current goal as introduction rule and not having "HOL."
  1107 in their name (i.e. not being defined in theory HOL).
  1108 
  1109 * Command 'thms_containing' has been discontinued in favour of
  1110 'find_theorems'; INCOMPATIBILITY.
  1111 
  1112 * Communication with Proof General is now 8bit clean, which means that
  1113 Unicode text in UTF-8 encoding may be used within theory texts (both
  1114 formal and informal parts).  Cf. option -U of the Isabelle Proof
  1115 General interface.  Here are some simple examples (cf. src/HOL/ex):
  1116 
  1117   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  1118   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  1119 
  1120 * Improved efficiency of the Simplifier and, to a lesser degree, the
  1121 Classical Reasoner.  Typical big applications run around 2 times
  1122 faster.
  1123 
  1124 
  1125 *** Document preparation ***
  1126 
  1127 * Commands 'display_drafts' and 'print_drafts' perform simple output
  1128 of raw sources.  Only those symbols that do not require additional
  1129 LaTeX packages (depending on comments in isabellesym.sty) are
  1130 displayed properly, everything else is left verbatim.  isatool display
  1131 and isatool print are used as front ends (these are subject to the
  1132 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  1133 
  1134 * Command tags control specific markup of certain regions of text,
  1135 notably folding and hiding.  Predefined tags include "theory" (for
  1136 theory begin and end), "proof" for proof commands, and "ML" for
  1137 commands involving ML code; the additional tags "visible" and
  1138 "invisible" are unused by default.  Users may give explicit tag
  1139 specifications in the text, e.g. ''by %invisible (auto)''.  The
  1140 interpretation of tags is determined by the LaTeX job during document
  1141 preparation: see option -V of isatool usedir, or options -n and -t of
  1142 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  1143 \isadroptag.
  1144 
  1145 Several document versions may be produced at the same time via isatool
  1146 usedir (the generated index.html will link all of them).  Typical
  1147 specifications include ''-V document=theory,proof,ML'' to present
  1148 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  1149 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  1150 these parts without any formal replacement text.  The Isabelle site
  1151 default settings produce ''document'' and ''outline'' versions as
  1152 specified above.
  1153 
  1154 * Several new antiquotations:
  1155 
  1156   @{term_type term} prints a term with its type annotated;
  1157 
  1158   @{typeof term} prints the type of a term;
  1159 
  1160   @{const const} is the same as @{term const}, but checks that the
  1161   argument is a known logical constant;
  1162 
  1163   @{term_style style term} and @{thm_style style thm} print a term or
  1164   theorem applying a "style" to it
  1165 
  1166   @{ML text}
  1167 
  1168 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  1169 definitions, equations, inequations etc., 'concl' printing only the
  1170 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  1171 to print the specified premise.  TermStyle.add_style provides an ML
  1172 interface for introducing further styles.  See also the "LaTeX Sugar"
  1173 document practical applications.  The ML antiquotation prints
  1174 type-checked ML expressions verbatim.
  1175 
  1176 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  1177 and 'text' support optional locale specification '(in loc)', which
  1178 specifies the default context for interpreting antiquotations.  For
  1179 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  1180 
  1181 * Option 'locale=NAME' of antiquotations specifies an alternative
  1182 context interpreting the subsequent argument.  For example: @{thm
  1183 [locale=lattice] inf_assoc}.
  1184 
  1185 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  1186 a proof context.
  1187 
  1188 * Proper output of antiquotations for theory commands involving a
  1189 proof context (such as 'locale' or 'theorem (in loc) ...').
  1190 
  1191 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  1192 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  1193 
  1194 * isatool usedir: new option -C (default true) controls whether option
  1195 -D should include a copy of the original document directory; -C false
  1196 prevents unwanted effects such as copying of administrative CVS data.
  1197 
  1198 
  1199 *** Pure ***
  1200 
  1201 * Considerably improved version of 'constdefs' command.  Now performs
  1202 automatic type-inference of declared constants; additional support for
  1203 local structure declarations (cf. locales and HOL records), see also
  1204 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  1205 sequential dependencies of definitions within a single 'constdefs'
  1206 section; moreover, the declared name needs to be an identifier.  If
  1207 all fails, consider to fall back on 'consts' and 'defs' separately.
  1208 
  1209 * Improved indexed syntax and implicit structures.  First of all,
  1210 indexed syntax provides a notational device for subscripted
  1211 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  1212 expressions.  Secondly, in a local context with structure
  1213 declarations, number indexes \<^sub>n or the empty index (default
  1214 number 1) refer to a certain fixed variable implicitly; option
  1215 show_structs controls printing of implicit structures.  Typical
  1216 applications of these concepts involve record types and locales.
  1217 
  1218 * New command 'no_syntax' removes grammar declarations (and
  1219 translations) resulting from the given syntax specification, which is
  1220 interpreted in the same manner as for the 'syntax' command.
  1221 
  1222 * 'Advanced' translation functions (parse_translation etc.) may depend
  1223 on the signature of the theory context being presently used for
  1224 parsing/printing, see also isar-ref manual.
  1225 
  1226 * Improved 'oracle' command provides a type-safe interface to turn an
  1227 ML expression of type theory -> T -> term into a primitive rule of
  1228 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  1229 is already included here); see also FOL/ex/IffExample.thy;
  1230 INCOMPATIBILITY.
  1231 
  1232 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  1233 before); "cI" is no longer bound, use "c.intro" instead.
  1234 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  1235 axclasses vs. locales.
  1236 
  1237 * Improved internal renaming of symbolic identifiers -- attach primes
  1238 instead of base 26 numbers.
  1239 
  1240 * New flag show_question_marks controls printing of leading question
  1241 marks in schematic variable names.
  1242 
  1243 * In schematic variable names, *any* symbol following \<^isub> or
  1244 \<^isup> is now treated as part of the base name.  For example, the
  1245 following works without printing of awkward ".0" indexes:
  1246 
  1247   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  1248     by simp
  1249 
  1250 * Inner syntax includes (*(*nested*) comments*).
  1251 
  1252 * Pretty printer now supports unbreakable blocks, specified in mixfix
  1253 annotations as "(00...)".
  1254 
  1255 * Clear separation of logical types and nonterminals, where the latter
  1256 may only occur in 'syntax' specifications or type abbreviations.
  1257 Before that distinction was only partially implemented via type class
  1258 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  1259 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  1260 exotic syntax specifications may require further adaption
  1261 (e.g. Cube/Cube.thy).
  1262 
  1263 * Removed obsolete type class "logic", use the top sort {} instead.
  1264 Note that non-logical types should be declared as 'nonterminals'
  1265 rather than 'types'.  INCOMPATIBILITY for new object-logic
  1266 specifications.
  1267 
  1268 * Attributes 'induct' and 'cases': type or set names may now be
  1269 locally fixed variables as well.
  1270 
  1271 * Simplifier: can now control the depth to which conditional rewriting
  1272 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  1273 Limit.
  1274 
  1275 * Simplifier: simplification procedures may now take the current
  1276 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  1277 interface), which is very useful for calling the Simplifier
  1278 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  1279 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  1280 low-level mk_simproc no longer applies Logic.varify internally, to
  1281 allow for use in a context of fixed variables.
  1282 
  1283 * thin_tac now works even if the assumption being deleted contains !!
  1284 or ==>.  More generally, erule now works even if the major premise of
  1285 the elimination rule contains !! or ==>.
  1286 
  1287 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  1288 
  1289 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  1290 from Pure, which contains all common declarations already.  Both
  1291 theories are defined via plain Isabelle/Isar .thy files.
  1292 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  1293 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  1294 use isatool fixcpure to adapt your theory and ML sources.
  1295 
  1296 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  1297 selections of theorems in named facts via index ranges.
  1298 
  1299 * 'print_theorems': in theory mode, really print the difference
  1300 wrt. the last state (works for interactive theory development only),
  1301 in proof mode print all local facts (cf. 'print_facts');
  1302 
  1303 * 'hide': option '(open)' hides only base names.
  1304 
  1305 * More efficient treatment of intermediate checkpoints in interactive
  1306 theory development.
  1307 
  1308 * Code generator is now invoked via code_module (incremental code
  1309 generation) and code_library (modular code generation, ML structures
  1310 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  1311 must be quoted when used as identifiers.
  1312 
  1313 * New 'value' command for reading, evaluating and printing terms using
  1314 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  1315 quoted when used as identifier.
  1316 
  1317 
  1318 *** Locales ***
  1319 
  1320 * New commands for the interpretation of locale expressions in
  1321 theories (1), locales (2) and proof contexts (3).  These generate
  1322 proof obligations from the expression specification.  After the
  1323 obligations have been discharged, theorems of the expression are added
  1324 to the theory, target locale or proof context.  The synopsis of the
  1325 commands is a follows:
  1326 
  1327   (1) interpretation expr inst
  1328   (2) interpretation target < expr
  1329   (3) interpret expr inst
  1330 
  1331 Interpretation in theories and proof contexts require a parameter
  1332 instantiation of terms from the current context.  This is applied to
  1333 specifications and theorems of the interpreted expression.
  1334 Interpretation in locales only permits parameter renaming through the
  1335 locale expression.  Interpretation is smart in that interpretations
  1336 that are active already do not occur in proof obligations, neither are
  1337 instantiated theorems stored in duplicate.  Use 'print_interps' to
  1338 inspect active interpretations of a particular locale.  For details,
  1339 see the Isar Reference manual.  Examples can be found in
  1340 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  1341 
  1342 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  1343 'interpret' instead.
  1344 
  1345 * New context element 'constrains' for adding type constraints to
  1346 parameters.
  1347 
  1348 * Context expressions: renaming of parameters with syntax
  1349 redeclaration.
  1350 
  1351 * Locale declaration: 'includes' disallowed.
  1352 
  1353 * Proper static binding of attribute syntax -- i.e. types / terms /
  1354 facts mentioned as arguments are always those of the locale definition
  1355 context, independently of the context of later invocations.  Moreover,
  1356 locale operations (renaming and type / term instantiation) are applied
  1357 to attribute arguments as expected.
  1358 
  1359 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  1360 actual attributes; rare situations may require Attrib.attribute to
  1361 embed those attributes into Attrib.src that lack concrete syntax.
  1362 Attribute implementations need to cooperate properly with the static
  1363 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  1364 Attrib.XXX_thm etc. already do the right thing without further
  1365 intervention.  Only unusual applications -- such as "where" or "of"
  1366 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  1367 on the context and the facts involved -- may have to assign parsed
  1368 values to argument tokens explicitly.
  1369 
  1370 * Changed parameter management in theorem generation for long goal
  1371 statements with 'includes'.  INCOMPATIBILITY: produces a different
  1372 theorem statement in rare situations.
  1373 
  1374 * Locale inspection command 'print_locale' omits notes elements.  Use
  1375 'print_locale!' to have them included in the output.
  1376 
  1377 
  1378 *** Provers ***
  1379 
  1380 * Provers/hypsubst.ML: improved version of the subst method, for
  1381 single-step rewriting: it now works in bound variable contexts. New is
  1382 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  1383 rewrite a different subterm than the original subst method, which is
  1384 still available as 'simplesubst'.
  1385 
  1386 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  1387 and quasi orders.
  1388 
  1389 * Provers/trancl.ML: new transitivity reasoner for transitive and
  1390 reflexive-transitive closure of relations.
  1391 
  1392 * Provers/blast.ML: new reference depth_limit to make blast's depth
  1393 limit (previously hard-coded with a value of 20) user-definable.
  1394 
  1395 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  1396 is peformed already.  Object-logics merely need to finish their
  1397 initial simpset configuration as before.  INCOMPATIBILITY.
  1398 
  1399 
  1400 *** HOL ***
  1401 
  1402 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  1403 
  1404   syntax (epsilon)
  1405     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  1406 
  1407 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  1408 and x-symbol; use option '-m epsilon' to get it actually printed.
  1409 Moreover, the mathematically important symbolic identifier \<epsilon>
  1410 becomes available as variable, constant etc.  INCOMPATIBILITY,
  1411 
  1412 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  1413 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  1414 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  1415 support corresponding Isar calculations.
  1416 
  1417 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  1418 instead of ":".
  1419 
  1420 * theory SetInterval: changed the syntax for open intervals:
  1421 
  1422   Old       New
  1423   {..n(}    {..<n}
  1424   {)n..}    {n<..}
  1425   {m..n(}   {m..<n}
  1426   {)m..n}   {m<..n}
  1427   {)m..n(}  {m<..<n}
  1428 
  1429 The old syntax is still supported but will disappear in the next
  1430 release.  For conversion use the following Emacs search and replace
  1431 patterns (these are not perfect but work quite well):
  1432 
  1433   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  1434   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  1435 
  1436 * Theory Commutative_Ring (in Library): method comm_ring for proving
  1437 equalities in commutative rings; method 'algebra' provides a generic
  1438 interface.
  1439 
  1440 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  1441 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  1442 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  1443 be a tuple pattern.
  1444 
  1445 Some new syntax forms are available:
  1446 
  1447   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  1448   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  1449   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  1450   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  1451 
  1452 The latter form "\<Sum>x < k. e" used to be based on a separate
  1453 function "Summation", which has been discontinued.
  1454 
  1455 * theory Finite_Set: in structured induction proofs, the insert case
  1456 is now 'case (insert x F)' instead of the old counterintuitive 'case
  1457 (insert F x)'.
  1458 
  1459 * The 'refute' command has been extended to support a much larger
  1460 fragment of HOL, including axiomatic type classes, constdefs and
  1461 typedefs, inductive datatypes and recursion.
  1462 
  1463 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  1464 Requires zChaff with proof generation to be installed.  See
  1465 HOL/ex/SAT_Examples.thy for examples.
  1466 
  1467 * Datatype induction via method 'induct' now preserves the name of the
  1468 induction variable. For example, when proving P(xs::'a list) by
  1469 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  1470 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  1471 in unstructured proof scripts.
  1472 
  1473 * Reworked implementation of records.  Improved scalability for
  1474 records with many fields, avoiding performance problems for type
  1475 inference. Records are no longer composed of nested field types, but
  1476 of nested extension types. Therefore the record type only grows linear
  1477 in the number of extensions and not in the number of fields.  The
  1478 top-level (users) view on records is preserved.  Potential
  1479 INCOMPATIBILITY only in strange cases, where the theory depends on the
  1480 old record representation. The type generated for a record is called
  1481 <record_name>_ext_type.
  1482 
  1483 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  1484 proofs triggered by a record definition or a simproc (if
  1485 quick_and_dirty is enabled).  Definitions of large records can take
  1486 quite long.
  1487 
  1488 New simproc record_upd_simproc for simplification of multiple record
  1489 updates enabled by default.  Moreover, trivial updates are also
  1490 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  1491 occasionally, since simplification is more powerful by default.
  1492 
  1493 * typedef: proper support for polymorphic sets, which contain extra
  1494 type-variables in the term.
  1495 
  1496 * Simplifier: automatically reasons about transitivity chains
  1497 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  1498 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  1499 old proofs break occasionally as simplification may now solve more
  1500 goals than previously.
  1501 
  1502 * Simplifier: converts x <= y into x = y if assumption y <= x is
  1503 present.  Works for all partial orders (class "order"), in particular
  1504 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  1505 just like y <= x.
  1506 
  1507 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  1508 bound variable or a constant then the let is unfolded.  Otherwise
  1509 first a is simplified to b, and then f b is simplified to g. If
  1510 possible we abstract b from g arriving at "let x = b in h x",
  1511 otherwise we unfold the let and arrive at g.  The simproc can be
  1512 enabled/disabled by the reference use_let_simproc.  Potential
  1513 INCOMPATIBILITY since simplification is more powerful by default.
  1514 
  1515 * Classical reasoning: the meson method now accepts theorems as arguments.
  1516 
  1517 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  1518 jobs to provide advice on the provability of subgoals.
  1519 
  1520 * Theory OrderedGroup and Ring_and_Field: various additions and
  1521 improvements to faciliate calculations involving equalities and
  1522 inequalities.
  1523 
  1524 The following theorems have been eliminated or modified
  1525 (INCOMPATIBILITY):
  1526 
  1527   abs_eq             now named abs_of_nonneg
  1528   abs_of_ge_0        now named abs_of_nonneg
  1529   abs_minus_eq       now named abs_of_nonpos
  1530   imp_abs_id         now named abs_of_nonneg
  1531   imp_abs_neg_id     now named abs_of_nonpos
  1532   mult_pos           now named mult_pos_pos
  1533   mult_pos_le        now named mult_nonneg_nonneg
  1534   mult_pos_neg_le    now named mult_nonneg_nonpos
  1535   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  1536   mult_neg           now named mult_neg_neg
  1537   mult_neg_le        now named mult_nonpos_nonpos
  1538 
  1539 * Theory Parity: added rules for simplifying exponents.
  1540 
  1541 * Theory List:
  1542 
  1543 The following theorems have been eliminated or modified
  1544 (INCOMPATIBILITY):
  1545 
  1546   list_all_Nil       now named list_all.simps(1)
  1547   list_all_Cons      now named list_all.simps(2)
  1548   list_all_conv      now named list_all_iff
  1549   set_mem_eq         now named mem_iff
  1550 
  1551 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  1552 asymptotic "big O" calculations.  See the notes in BigO.thy.
  1553 
  1554 
  1555 *** HOL-Complex ***
  1556 
  1557 * Theory RealDef: better support for embedding natural numbers and
  1558 integers in the reals.
  1559 
  1560 The following theorems have been eliminated or modified
  1561 (INCOMPATIBILITY):
  1562 
  1563   exp_ge_add_one_self  now requires no hypotheses
  1564   real_of_int_add      reversed direction of equality (use [symmetric])
  1565   real_of_int_minus    reversed direction of equality (use [symmetric])
  1566   real_of_int_diff     reversed direction of equality (use [symmetric])
  1567   real_of_int_mult     reversed direction of equality (use [symmetric])
  1568 
  1569 * Theory RComplete: expanded support for floor and ceiling functions.
  1570 
  1571 * Theory Ln is new, with properties of the natural logarithm
  1572 
  1573 * Hyperreal: There is a new type constructor "star" for making
  1574 nonstandard types.  The old type names are now type synonyms:
  1575 
  1576   hypreal = real star
  1577   hypnat = nat star
  1578   hcomplex = complex star
  1579 
  1580 * Hyperreal: Many groups of similarly-defined constants have been
  1581 replaced by polymorphic versions (INCOMPATIBILITY):
  1582 
  1583   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  1584 
  1585   starset      <-- starsetNat, starsetC
  1586   *s*          <-- *sNat*, *sc*
  1587   starset_n    <-- starsetNat_n, starsetC_n
  1588   *sn*         <-- *sNatn*, *scn*
  1589   InternalSets <-- InternalNatSets, InternalCSets
  1590 
  1591   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  1592   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  1593   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  1594   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  1595   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  1596 
  1597 * Hyperreal: Many type-specific theorems have been removed in favor of
  1598 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  1599 
  1600   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  1601   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  1602   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  1603   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  1604   right_minus <-- hypreal_add_minus
  1605   left_minus <-- {hypreal,hcomplex}_add_minus_left
  1606   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  1607   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  1608   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  1609   mult_1_right <-- hcomplex_mult_one_right
  1610   mult_zero_left <-- hcomplex_mult_zero_left
  1611   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  1612   right_distrib <-- hypnat_add_mult_distrib2
  1613   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  1614   right_inverse <-- hypreal_mult_inverse
  1615   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  1616   order_refl <-- {hypreal,hypnat}_le_refl
  1617   order_trans <-- {hypreal,hypnat}_le_trans
  1618   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  1619   order_less_le <-- {hypreal,hypnat}_less_le
  1620   linorder_linear <-- {hypreal,hypnat}_le_linear
  1621   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  1622   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  1623   add_nonneg_nonneg <-- hypreal_le_add_order
  1624 
  1625 * Hyperreal: Separate theorems having to do with type-specific
  1626 versions of constants have been merged into theorems that apply to the
  1627 new polymorphic constants (INCOMPATIBILITY):
  1628 
  1629   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  1630   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  1631   STAR_Un <-- {STAR,NatStar,STARC}_Un
  1632   STAR_Int <-- {STAR,NatStar,STARC}_Int
  1633   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  1634   STAR_subset <-- {STAR,NatStar,STARC}_subset
  1635   STAR_mem <-- {STAR,NatStar,STARC}_mem
  1636   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  1637   STAR_diff <-- {STAR,STARC}_diff
  1638   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  1639     STARC_hcomplex_of_complex}_image_subset
  1640   starset_n_Un <-- starset{Nat,C}_n_Un
  1641   starset_n_Int <-- starset{Nat,C}_n_Int
  1642   starset_n_Compl <-- starset{Nat,C}_n_Compl
  1643   starset_n_diff <-- starset{Nat,C}_n_diff
  1644   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  1645   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  1646   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  1647   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  1648   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  1649   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  1650   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  1651   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  1652   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  1653   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  1654   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  1655   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  1656   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  1657   starfun_diff <-- starfun{C,RC,CR}_diff
  1658   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  1659   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  1660   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  1661   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  1662   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  1663   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  1664   starfun_Id <-- starfunC_Id
  1665   starfun_approx <-- starfun{Nat,CR}_approx
  1666   starfun_capprox <-- starfun{C,RC}_capprox
  1667   starfun_abs <-- starfunNat_rabs
  1668   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  1669   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  1670   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  1671   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  1672   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  1673   starfun_add_approx <-- starfunCR_add_approx
  1674   starfun_inverse_inverse <-- starfunC_inverse_inverse
  1675   starfun_divide <-- starfun{C,CR,RC}_divide
  1676   starfun_n <-- starfun{Nat,C}_n
  1677   starfun_n_mult <-- starfun{Nat,C}_n_mult
  1678   starfun_n_add <-- starfun{Nat,C}_n_add
  1679   starfun_n_add_minus <-- starfunNat_n_add_minus
  1680   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  1681   starfun_n_minus <-- starfun{Nat,C}_n_minus
  1682   starfun_n_eq <-- starfun{Nat,C}_n_eq
  1683 
  1684   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  1685   star_n_minus <-- {hypreal,hcomplex}_minus
  1686   star_n_diff <-- {hypreal,hcomplex}_diff
  1687   star_n_mult <-- {hypreal,hcomplex}_mult
  1688   star_n_inverse <-- {hypreal,hcomplex}_inverse
  1689   star_n_le <-- {hypreal,hypnat}_le
  1690   star_n_less <-- {hypreal,hypnat}_less
  1691   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  1692   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  1693   star_n_abs <-- hypreal_hrabs
  1694   star_n_divide <-- hcomplex_divide
  1695 
  1696   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  1697   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  1698   star_of_diff <-- hypreal_of_real_diff
  1699   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  1700   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  1701   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  1702   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  1703   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  1704   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  1705   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  1706   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  1707   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  1708   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  1709   star_of_number_of <-- {hypreal,hcomplex}_number_of
  1710   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  1711   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  1712   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  1713   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  1714   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  1715   star_of_power <-- hypreal_of_real_power
  1716   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  1717 
  1718 * Hyperreal: new method "transfer" that implements the transfer
  1719 principle of nonstandard analysis. With a subgoal that mentions
  1720 nonstandard types like "'a star", the command "apply transfer"
  1721 replaces it with an equivalent one that mentions only standard types.
  1722 To be successful, all free variables must have standard types; non-
  1723 standard variables must have explicit universal quantifiers.
  1724 
  1725 * Hyperreal: A theory of Taylor series.
  1726 
  1727 
  1728 *** HOLCF ***
  1729 
  1730 * Discontinued special version of 'constdefs' (which used to support
  1731 continuous functions) in favor of the general Pure one with full
  1732 type-inference.
  1733 
  1734 * New simplification procedure for solving continuity conditions; it
  1735 is much faster on terms with many nested lambda abstractions (cubic
  1736 instead of exponential time).
  1737 
  1738 * New syntax for domain package: selector names are now optional.
  1739 Parentheses should be omitted unless argument is lazy, for example:
  1740 
  1741   domain 'a stream = cons "'a" (lazy "'a stream")
  1742 
  1743 * New command 'fixrec' for defining recursive functions with pattern
  1744 matching; defining multiple functions with mutual recursion is also
  1745 supported.  Patterns may include the constants cpair, spair, up, sinl,
  1746 sinr, or any data constructor defined by the domain package. The given
  1747 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  1748 syntax and examples.
  1749 
  1750 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  1751 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  1752 but the proof obligation additionally includes an admissibility
  1753 requirement. The packages generate instances of class cpo or pcpo,
  1754 with continuity and strictness theorems for Rep and Abs.
  1755 
  1756 * HOLCF: Many theorems have been renamed according to a more standard naming
  1757 scheme (INCOMPATIBILITY):
  1758 
  1759   foo_inject:  "foo$x = foo$y ==> x = y"
  1760   foo_eq:      "(foo$x = foo$y) = (x = y)"
  1761   foo_less:    "(foo$x << foo$y) = (x << y)"
  1762   foo_strict:  "foo$UU = UU"
  1763   foo_defined: "... ==> foo$x ~= UU"
  1764   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  1765 
  1766 
  1767 *** ZF ***
  1768 
  1769 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  1770 including the First Isomorphism Theorem (on quotienting by the kernel
  1771 of a homomorphism).
  1772 
  1773 * ZF/Simplifier: install second copy of type solver that actually
  1774 makes use of TC rules declared to Isar proof contexts (or locales);
  1775 the old version is still required for ML proof scripts.
  1776 
  1777 
  1778 *** Cube ***
  1779 
  1780 * Converted to Isar theory format; use locales instead of axiomatic
  1781 theories.
  1782 
  1783 
  1784 *** ML ***
  1785 
  1786 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  1787 for ||>, ||>>, |>>,
  1788 
  1789 * Pure/library.ML no longer defines its own option datatype, but uses
  1790 that of the SML basis, which has constructors NONE and SOME instead of
  1791 None and Some, as well as exception Option.Option instead of OPTION.
  1792 The functions the, if_none, is_some, is_none have been adapted
  1793 accordingly, while Option.map replaces apsome.
  1794 
  1795 * Pure/library.ML: the exception LIST has been given up in favour of
  1796 the standard exceptions Empty and Subscript, as well as
  1797 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  1798 superceded by the standard hd and tl functions etc.
  1799 
  1800 A number of basic list functions are no longer exported to the ML
  1801 toplevel, as they are variants of predefined functions.  The following
  1802 suggests how one can translate existing code:
  1803 
  1804     rev_append xs ys = List.revAppend (xs, ys)
  1805     nth_elem (i, xs) = List.nth (xs, i)
  1806     last_elem xs = List.last xs
  1807     flat xss = List.concat xss
  1808     seq fs = List.app fs
  1809     partition P xs = List.partition P xs
  1810     mapfilter f xs = List.mapPartial f xs
  1811 
  1812 * Pure/library.ML: several combinators for linear functional
  1813 transformations, notably reverse application and composition:
  1814 
  1815   x |> f                f #> g
  1816   (x, y) |-> f          f #-> g
  1817 
  1818 * Pure/library.ML: introduced/changed precedence of infix operators:
  1819 
  1820   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  1821   infix 2 ?;
  1822   infix 3 o oo ooo oooo;
  1823   infix 4 ~~ upto downto;
  1824 
  1825 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  1826 infix operators.
  1827 
  1828 * Pure/library.ML: natural list combinators fold, fold_rev, and
  1829 fold_map support linear functional transformations and nesting.  For
  1830 example:
  1831 
  1832   fold f [x1, ..., xN] y =
  1833     y |> f x1 |> ... |> f xN
  1834 
  1835   (fold o fold) f [xs1, ..., xsN] y =
  1836     y |> fold f xs1 |> ... |> fold f xsN
  1837 
  1838   fold f [x1, ..., xN] =
  1839     f x1 #> ... #> f xN
  1840 
  1841   (fold o fold) f [xs1, ..., xsN] =
  1842     fold f xs1 #> ... #> fold f xsN
  1843 
  1844 * Pure/library.ML: the following selectors on type 'a option are
  1845 available:
  1846 
  1847   the:               'a option -> 'a  (*partial*)
  1848   these:             'a option -> 'a  where 'a = 'b list
  1849   the_default: 'a -> 'a option -> 'a
  1850   the_list:          'a option -> 'a list
  1851 
  1852 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  1853 basic operations for association lists, following natural argument
  1854 order; moreover the explicit equality predicate passed here avoids
  1855 potentially expensive polymorphic runtime equality checks.
  1856 The old functions may be expressed as follows:
  1857 
  1858   assoc = uncurry (AList.lookup (op =))
  1859   assocs = these oo AList.lookup (op =)
  1860   overwrite = uncurry (AList.update (op =)) o swap
  1861 
  1862 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  1863 
  1864   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  1865   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  1866 
  1867 replacing make_keylist and keyfilter (occassionally used)
  1868 Naive rewrites:
  1869 
  1870   make_keylist = AList.make
  1871   keyfilter = AList.find (op =)
  1872 
  1873 * eq_fst and eq_snd now take explicit equality parameter, thus
  1874   avoiding eqtypes. Naive rewrites:
  1875 
  1876     eq_fst = eq_fst (op =)
  1877     eq_snd = eq_snd (op =)
  1878 
  1879 * Removed deprecated apl and apr (rarely used).
  1880   Naive rewrites:
  1881 
  1882     apl (n, op) =>>= curry op n
  1883     apr (op, m) =>>= fn n => op (n, m)
  1884 
  1885 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  1886 provides a reasonably efficient light-weight implementation of sets as
  1887 lists.
  1888 
  1889 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  1890 few new operations; existing lookup and update are now curried to
  1891 follow natural argument order (for use with fold etc.);
  1892 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  1893 
  1894 * Pure/General: output via the Isabelle channels of
  1895 writeln/warning/error etc. is now passed through Output.output, with a
  1896 hook for arbitrary transformations depending on the print_mode
  1897 (cf. Output.add_mode -- the first active mode that provides a output
  1898 function wins).  Already formatted output may be embedded into further
  1899 text via Output.raw; the result of Pretty.string_of/str_of and derived
  1900 functions (string_of_term/cterm/thm etc.) is already marked raw to
  1901 accommodate easy composition of diagnostic messages etc.  Programmers
  1902 rarely need to care about Output.output or Output.raw at all, with
  1903 some notable exceptions: Output.output is required when bypassing the
  1904 standard channels (writeln etc.), or in token translations to produce
  1905 properly formatted results; Output.raw is required when capturing
  1906 already output material that will eventually be presented to the user
  1907 a second time.  For the default print mode, both Output.output and
  1908 Output.raw have no effect.
  1909 
  1910 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  1911 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  1912 cumulative results are displayed at the end of a batch session.
  1913 
  1914 * Pure/General: File.sysify_path and File.quote_sysify path have been
  1915 replaced by File.platform_path and File.shell_path (with appropriate
  1916 hooks).  This provides a clean interface for unusual systems where the
  1917 internal and external process view of file names are different.
  1918 
  1919 * Pure: more efficient orders for basic syntactic entities: added
  1920 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  1921 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  1922 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  1923 orders now -- potential INCOMPATIBILITY for code that depends on a
  1924 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  1925 Library.sort_strings on result).
  1926 
  1927 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  1928 fold_types traverse types/terms from left to right, observing natural
  1929 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  1930 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  1931 
  1932 * Pure: name spaces have been refined, with significant changes of the
  1933 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  1934 to extern(_table).  The plain name entry path is superceded by a
  1935 general 'naming' context, which also includes the 'policy' to produce
  1936 a fully qualified name and external accesses of a fully qualified
  1937 name; NameSpace.extend is superceded by context dependent
  1938 Sign.declare_name.  Several theory and proof context operations modify
  1939 the naming context.  Especially note Theory.restore_naming and
  1940 ProofContext.restore_naming to get back to a sane state; note that
  1941 Theory.add_path is no longer sufficient to recover from
  1942 Theory.absolute_path in particular.
  1943 
  1944 * Pure: new flags short_names (default false) and unique_names
  1945 (default true) for controlling output of qualified names.  If
  1946 short_names is set, names are printed unqualified.  If unique_names is
  1947 reset, the name prefix is reduced to the minimum required to achieve
  1948 the original result when interning again, even if there is an overlap
  1949 with earlier declarations.
  1950 
  1951 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  1952 now 'extend', and 'merge' gets an additional Pretty.pp argument
  1953 (useful for printing error messages).  INCOMPATIBILITY.
  1954 
  1955 * Pure: major reorganization of the theory context.  Type Sign.sg and
  1956 Theory.theory are now identified, referring to the universal
  1957 Context.theory (see Pure/context.ML).  Actual signature and theory
  1958 content is managed as theory data.  The old code and interfaces were
  1959 spread over many files and structures; the new arrangement introduces
  1960 considerable INCOMPATIBILITY to gain more clarity:
  1961 
  1962   Context -- theory management operations (name, identity, inclusion,
  1963     parents, ancestors, merge, etc.), plus generic theory data;
  1964 
  1965   Sign -- logical signature and syntax operations (declaring consts,
  1966     types, etc.), plus certify/read for common entities;
  1967 
  1968   Theory -- logical theory operations (stating axioms, definitions,
  1969     oracles), plus a copy of logical signature operations (consts,
  1970     types, etc.); also a few basic management operations (Theory.copy,
  1971     Theory.merge, etc.)
  1972 
  1973 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  1974 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  1975 for convenience -- they merely return the theory.
  1976 
  1977 * Pure: type Type.tsig is superceded by theory in most interfaces.
  1978 
  1979 * Pure: the Isar proof context type is already defined early in Pure
  1980 as Context.proof (note that ProofContext.context and Proof.context are
  1981 aliases, where the latter is the preferred name).  This enables other
  1982 Isabelle components to refer to that type even before Isar is present.
  1983 
  1984 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  1985 typeK, constK, axiomK, oracleK), but provide explicit operations for
  1986 any of these kinds.  For example, Sign.intern typeK is now
  1987 Sign.intern_type, Theory.hide_space Sign.typeK is now
  1988 Theory.hide_types.  Also note that former
  1989 Theory.hide_classes/types/consts are now
  1990 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  1991 internalize their arguments!  INCOMPATIBILITY.
  1992 
  1993 * Pure: get_thm interface (of PureThy and ProofContext) expects
  1994 datatype thmref (with constructors Name and NameSelection) instead of
  1995 plain string -- INCOMPATIBILITY;
  1996 
  1997 * Pure: cases produced by proof methods specify options, where NONE
  1998 means to remove case bindings -- INCOMPATIBILITY in
  1999 (RAW_)METHOD_CASES.
  2000 
  2001 * Pure: the following operations retrieve axioms or theorems from a
  2002 theory node or theory hierarchy, respectively:
  2003 
  2004   Theory.axioms_of: theory -> (string * term) list
  2005   Theory.all_axioms_of: theory -> (string * term) list
  2006   PureThy.thms_of: theory -> (string * thm) list
  2007   PureThy.all_thms_of: theory -> (string * thm) list
  2008 
  2009 * Pure: print_tac now outputs the goal through the trace channel.
  2010 
  2011 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  2012 Reference Toplevel.debug (default false) controls detailed printing
  2013 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  2014 controls execution profiling -- set to 1 for time and 2 for space
  2015 (both increase the runtime).
  2016 
  2017 * Isar session: The initial use of ROOT.ML is now always timed,
  2018 i.e. the log will show the actual process times, in contrast to the
  2019 elapsed wall-clock time that the outer shell wrapper produces.
  2020 
  2021 * Simplifier: improved handling of bound variables (nameless
  2022 representation, avoid allocating new strings).  Simprocs that invoke
  2023 the Simplifier recursively should use Simplifier.inherit_bounds to
  2024 avoid local name clashes.  Failure to do so produces warnings
  2025 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  2026 for further details.
  2027 
  2028 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  2029 bindings for all theorems stored within a given theory; this may help
  2030 in porting non-Isar theories to Isar ones, while keeping ML proof
  2031 scripts for the time being.
  2032 
  2033 * ML operator HTML.with_charset specifies the charset begin used for
  2034 generated HTML files.  For example:
  2035 
  2036   HTML.with_charset "utf-8" use_thy "Hebrew";
  2037   HTML.with_charset "utf-8" use_thy "Chinese";
  2038 
  2039 
  2040 *** System ***
  2041 
  2042 * Allow symlinks to all proper Isabelle executables (Isabelle,
  2043 isabelle, isatool etc.).
  2044 
  2045 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  2046 isatool doc, isatool mkdir, display_drafts etc.).
  2047 
  2048 * isatool usedir: option -f allows specification of the ML file to be
  2049 used by Isabelle; default is ROOT.ML.
  2050 
  2051 * New isatool version outputs the version identifier of the Isabelle
  2052 distribution being used.
  2053 
  2054 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  2055 (containing Boolean satisfiability problems) into Isabelle/HOL
  2056 theories.
  2057 
  2058 
  2059 
  2060 New in Isabelle2004 (April 2004)
  2061 --------------------------------
  2062 
  2063 *** General ***
  2064 
  2065 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  2066   Replaces linorder.ML.
  2067 
  2068 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  2069   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  2070   (\<a>...\<z>), are now considered normal letters, and can therefore
  2071   be used anywhere where an ASCII letter (a...zA...Z) has until
  2072   now. COMPATIBILITY: This obviously changes the parsing of some
  2073   terms, especially where a symbol has been used as a binder, say
  2074   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  2075   as an identifier.  Fix it by inserting a space around former
  2076   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  2077   existing theory and ML files.
  2078 
  2079 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  2080 
  2081 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  2082   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  2083   a normal (but invisible) letter. For multiple letter subscripts repeat
  2084   \<^isub> like this: x\<^isub>1\<^isub>2.
  2085 
  2086 * Pure: There are now sub-/superscripts that can span more than one
  2087   character. Text between \<^bsub> and \<^esub> is set in subscript in
  2088   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  2089   superscript. The new control characters are not identifier parts.
  2090 
  2091 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  2092   content of "..." to the latex file instead of \isacntrl... . The "..."
  2093   may consist of any printable characters excluding the end bracket >.
  2094 
  2095 * Pure: Using new Isar command "finalconsts" (or the ML functions
  2096   Theory.add_finals or Theory.add_finals_i) it is now possible to
  2097   declare constants "final", which prevents their being given a definition
  2098   later.  It is useful for constants whose behaviour is fixed axiomatically
  2099   rather than definitionally, such as the meta-logic connectives.
  2100 
  2101 * Pure: 'instance' now handles general arities with general sorts
  2102   (i.e. intersections of classes),
  2103 
  2104 * Presentation: generated HTML now uses a CSS style sheet to make layout
  2105   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  2106   It can be changed to alter the colors/layout of generated pages.
  2107 
  2108 
  2109 *** Isar ***
  2110 
  2111 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  2112   cut_tac, subgoal_tac and thin_tac:
  2113   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  2114     locales are no longer forced to write Isar proof scripts.
  2115     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  2116     emulations.
  2117   - INCOMPATIBILITY: names of variables to be instantiated may no
  2118     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  2119     This is consistent with the instantiation attribute "where".
  2120 
  2121 * Attributes "where" and "of":
  2122   - Now take type variables of instantiated theorem into account when reading
  2123     the instantiation string.  This fixes a bug that caused instantiated
  2124     theorems to have too special types in some circumstances.
  2125   - "where" permits explicit instantiations of type variables.
  2126 
  2127 * Calculation commands "moreover" and "also" no longer interfere with
  2128   current facts ("this"), admitting arbitrary combinations with "then"
  2129   and derived forms.
  2130 
  2131 * Locales:
  2132   - Goal statements involving the context element "includes" no longer
  2133     generate theorems with internal delta predicates (those ending on
  2134     "_axioms") in the premise.
  2135     Resolve particular premise with <locale>.intro to obtain old form.
  2136   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  2137     specification and "includes" elements in goal statement.
  2138   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  2139     [intro?] and [elim?] (respectively) by default.
  2140   - Experimental command for instantiation of locales in proof contexts:
  2141         instantiate <label>[<attrs>]: <loc>
  2142     Instantiates locale <loc> and adds all its theorems to the current context
  2143     taking into account their attributes.  Label and attrs are optional
  2144     modifiers, like in theorem declarations.  If present, names of
  2145     instantiated theorems are qualified with <label>, and the attributes
  2146     <attrs> are applied after any attributes these theorems might have already.
  2147       If the locale has assumptions, a chained fact of the form
  2148     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  2149     are derived.  The command does not support old-style locales declared
  2150     with "locale (open)".
  2151       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  2152 
  2153 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  2154   (Isar) contexts.
  2155 
  2156 
  2157 *** HOL ***
  2158 
  2159 * Proof import: new image HOL4 contains the imported library from
  2160   the HOL4 system with about 2500 theorems. It is imported by
  2161   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  2162   can be used like any other Isabelle image.  See
  2163   HOL/Import/HOL/README for more information.
  2164 
  2165 * Simplifier:
  2166   - Much improved handling of linear and partial orders.
  2167     Reasoners for linear and partial orders are set up for type classes
  2168     "linorder" and "order" respectively, and are added to the default simpset
  2169     as solvers.  This means that the simplifier can build transitivity chains
  2170     to solve goals from the assumptions.
  2171   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  2172     of blast or auto after simplification become unnecessary because the goal
  2173     is solved by simplification already.
  2174 
  2175 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  2176     all proved in axiomatic type classes for semirings, rings and fields.
  2177 
  2178 * Numerics:
  2179   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  2180     now formalized using the Ring_and_Field theory mentioned above.
  2181   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  2182     than before, because now they are set up once in a generic manner.
  2183   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  2184     Look for the general versions in Ring_and_Field (and Power if they concern
  2185     exponentiation).
  2186 
  2187 * Type "rat" of the rational numbers is now available in HOL-Complex.
  2188 
  2189 * Records:
  2190   - Record types are now by default printed with their type abbreviation
  2191     instead of the list of all field types. This can be configured via
  2192     the reference "print_record_type_abbr".
  2193   - Simproc "record_upd_simproc" for simplification of multiple updates added
  2194     (not enabled by default).
  2195   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  2196     EX x. x = sel r to True (not enabled by default).
  2197   - Tactic "record_split_simp_tac" to split and simplify records added.
  2198 
  2199 * 'specification' command added, allowing for definition by
  2200   specification.  There is also an 'ax_specification' command that
  2201   introduces the new constants axiomatically.
  2202 
  2203 * arith(_tac) is now able to generate counterexamples for reals as well.
  2204 
  2205 * HOL-Algebra: new locale "ring" for non-commutative rings.
  2206 
  2207 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  2208   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  2209 
  2210 * HOL-Matrix: a first theory for matrices in HOL with an application of
  2211   matrix theory to linear programming.
  2212 
  2213 * Unions and Intersections:
  2214   The latex output syntax of UN and INT has been changed
  2215   from "\Union x \in A. B" to "\Union_{x \in A} B"
  2216   i.e. the index formulae has become a subscript.
  2217   Similarly for "\Union x. B", and for \Inter instead of \Union.
  2218 
  2219 * Unions and Intersections over Intervals:
  2220   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  2221   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  2222   like in normal math, and corresponding versions for < and for intersection.
  2223 
  2224 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  2225   lexicographic dictonary ordering has been added as "lexord".
  2226 
  2227 * ML: the legacy theory structures Int and List have been removed. They had
  2228   conflicted with ML Basis Library structures having the same names.
  2229 
  2230 * 'refute' command added to search for (finite) countermodels.  Only works
  2231   for a fragment of HOL.  The installation of an external SAT solver is
  2232   highly recommended.  See "HOL/Refute.thy" for details.
  2233 
  2234 * 'quickcheck' command: Allows to find counterexamples by evaluating
  2235   formulae under an assignment of free variables to random values.
  2236   In contrast to 'refute', it can deal with inductive datatypes,
  2237   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  2238   for examples.
  2239 
  2240 
  2241 *** HOLCF ***
  2242 
  2243 * Streams now come with concatenation and are part of the HOLCF image
  2244 
  2245 
  2246 
  2247 New in Isabelle2003 (May 2003)
  2248 ------------------------------
  2249 
  2250 *** General ***
  2251 
  2252 * Provers/simplifier:
  2253 
  2254   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  2255     Assumptions are now subject to complete mutual simplification,
  2256     not just from left to right. The simplifier now preserves
  2257     the order of assumptions.
  2258 
  2259     Potential INCOMPATIBILITY:
  2260 
  2261     -- simp sometimes diverges where the old version did
  2262        not, e.g. invoking simp on the goal
  2263 
  2264         [| P (f x); y = x; f x = f y |] ==> Q
  2265 
  2266        now gives rise to the infinite reduction sequence
  2267 
  2268         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  2269 
  2270        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  2271        kind of problem.
  2272 
  2273     -- Tactics combining classical reasoner and simplification (such as auto)
  2274        are also affected by this change, because many of them rely on
  2275        simp. They may sometimes diverge as well or yield a different numbers
  2276        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  2277        in case of problems. Sometimes subsequent calls to the classical
  2278        reasoner will fail because a preceeding call to the simplifier too
  2279        eagerly simplified the goal, e.g. deleted redundant premises.
  2280 
  2281   - The simplifier trace now shows the names of the applied rewrite rules
  2282 
  2283   - You can limit the number of recursive invocations of the simplifier
  2284     during conditional rewriting (where the simplifie tries to solve the
  2285     conditions before applying the rewrite rule):
  2286     ML "simp_depth_limit := n"
  2287     where n is an integer. Thus you can force termination where previously
  2288     the simplifier would diverge.
  2289 
  2290   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  2291 
  2292   - No longer aborts on failed congruence proof.  Instead, the
  2293     congruence is ignored.
  2294 
  2295 * Pure: New generic framework for extracting programs from constructive
  2296   proofs. See HOL/Extraction.thy for an example instantiation, as well
  2297   as HOL/Extraction for some case studies.
  2298 
  2299 * Pure: The main goal of the proof state is no longer shown by default, only
  2300 the subgoals. This behaviour is controlled by a new flag.
  2301    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  2302 (ML: Proof.show_main_goal).
  2303 
  2304 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  2305 rules whose conclusion matches subgoal 1:
  2306       PG menu: Isabelle/Isar -> Show me -> matching rules
  2307 The rules are ordered by how closely they match the subgoal.
  2308 In particular, rules that solve a subgoal outright are displayed first
  2309 (or rather last, the way they are printed).
  2310 (ML: ProofGeneral.print_intros())
  2311 
  2312 * Pure: New flag trace_unify_fail causes unification to print
  2313 diagnostic information (PG: in trace buffer) when it fails. This is
  2314 useful for figuring out why single step proofs like rule, erule or
  2315 assumption failed.
  2316 
  2317 * Pure: Locale specifications now produce predicate definitions
  2318 according to the body of text (covering assumptions modulo local
  2319 definitions); predicate "loc_axioms" covers newly introduced text,
  2320 while "loc" is cumulative wrt. all included locale expressions; the
  2321 latter view is presented only on export into the global theory
  2322 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  2323 on the old view without predicates;
  2324 
  2325 * Pure: predefined locales "var" and "struct" are useful for sharing
  2326 parameters (as in CASL, for example); just specify something like
  2327 ``var x + var y + struct M'' as import;
  2328 
  2329 * Pure: improved thms_containing: proper indexing of facts instead of
  2330 raw theorems; check validity of results wrt. current name space;
  2331 include local facts of proof configuration (also covers active
  2332 locales), cover fixed variables in index; may use "_" in term
  2333 specification; an optional limit for the number of printed facts may
  2334 be given (the default is 40);
  2335 
  2336 * Pure: disallow duplicate fact bindings within new-style theory files
  2337 (batch-mode only);
  2338 
  2339 * Provers: improved induct method: assumptions introduced by case
  2340 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  2341 the goal statement); "foo" still refers to all facts collectively;
  2342 
  2343 * Provers: the function blast.overloaded has been removed: all constants
  2344 are regarded as potentially overloaded, which improves robustness in exchange
  2345 for slight decrease in efficiency;
  2346 
  2347 * Provers/linorder: New generic prover for transitivity reasoning over
  2348 linear orders.  Note: this prover is not efficient!
  2349 
  2350 * Isar: preview of problems to finish 'show' now produce an error
  2351 rather than just a warning (in interactive mode);
  2352 
  2353 
  2354 *** HOL ***
  2355 
  2356 * arith(_tac)
  2357 
  2358  - Produces a counter example if it cannot prove a goal.
  2359    Note that the counter example may be spurious if the goal is not a formula
  2360    of quantifier-free linear arithmetic.
  2361    In ProofGeneral the counter example appears in the trace buffer.
  2362 
  2363  - Knows about div k and mod k where k is a numeral of type nat or int.
  2364 
  2365  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  2366    linear arithmetic fails. This takes account of quantifiers and divisibility.
  2367    Presburger arithmetic can also be called explicitly via presburger(_tac).
  2368 
  2369 * simp's arithmetic capabilities have been enhanced a bit: it now
  2370 takes ~= in premises into account (by performing a case split);
  2371 
  2372 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  2373 are distributed over a sum of terms;
  2374 
  2375 * New tactic "trans_tac" and method "trans" instantiate
  2376 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  2377 "<=", "<" and "=").
  2378 
  2379 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  2380 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  2381 
  2382 * 'typedef' command has new option "open" to suppress the set
  2383 definition;
  2384 
  2385 * functions Min and Max on finite sets have been introduced (theory
  2386 Finite_Set);
  2387 
  2388 * attribute [symmetric] now works for relations as well; it turns
  2389 (x,y) : R^-1 into (y,x) : R, and vice versa;
  2390 
  2391 * induct over a !!-quantified statement (say !!x1..xn):
  2392   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  2393 
  2394 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  2395 %x. None. Warning: empty_def now refers to the previously hidden definition
  2396 of the empty set.
  2397 
  2398 * Algebra: formalization of classical algebra.  Intended as base for
  2399 any algebraic development in Isabelle.  Currently covers group theory
  2400 (up to Sylow's theorem) and ring theory (Universal Property of
  2401 Univariate Polynomials).  Contributions welcome;
  2402 
  2403 * GroupTheory: deleted, since its material has been moved to Algebra;
  2404 
  2405 * Complex: new directory of the complex numbers with numeric constants,
  2406 nonstandard complex numbers, and some complex analysis, standard and
  2407 nonstandard (Jacques Fleuriot);
  2408 
  2409 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  2410 
  2411 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  2412 Fleuriot);
  2413 
  2414 * Real/HahnBanach: updated and adapted to locales;
  2415 
  2416 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  2417 Gray and Kramer);
  2418 
  2419 * UNITY: added the Meier-Sanders theory of progress sets;
  2420 
  2421 * MicroJava: bytecode verifier and lightweight bytecode verifier
  2422 as abstract algorithms, instantiated to the JVM;
  2423 
  2424 * Bali: Java source language formalization. Type system, operational
  2425 semantics, axiomatic semantics. Supported language features:
  2426 classes, interfaces, objects,virtual methods, static methods,
  2427 static/instance fields, arrays, access modifiers, definite
  2428 assignment, exceptions.
  2429 
  2430 
  2431 *** ZF ***
  2432 
  2433 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  2434 universe, etc.);
  2435 
  2436 * Main ZF: virtually all theories converted to new-style format;
  2437 
  2438 
  2439 *** ML ***
  2440 
  2441 * Pure: Tactic.prove provides sane interface for internal proofs;
  2442 omits the infamous "standard" operation, so this is more appropriate
  2443 than prove_goalw_cterm in many situations (e.g. in simprocs);
  2444 
  2445 * Pure: improved error reporting of simprocs;
  2446 
  2447 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  2448 up simprocs;
  2449 
  2450 
  2451 *** Document preparation ***
  2452 
  2453 * uses \par instead of \\ for line breaks in theory text. This may
  2454 shift some page breaks in large documents. To get the old behaviour
  2455 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  2456 
  2457 * minimized dependencies of isabelle.sty and isabellesym.sty on
  2458 other packages
  2459 
  2460 * \<euro> now needs package babel/greek instead of marvosym (which
  2461 broke \Rightarrow)
  2462 
  2463 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  2464 textcomp package)
  2465 
  2466 
  2467 
  2468 New in Isabelle2002 (March 2002)
  2469 --------------------------------
  2470 
  2471 *** Document preparation ***
  2472 
  2473 * greatly simplified document preparation setup, including more
  2474 graceful interpretation of isatool usedir -i/-d/-D options, and more
  2475 instructive isatool mkdir; users should basically be able to get
  2476 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  2477 users may run a separate document processing stage manually like this:
  2478 "isatool usedir -D output HOL Test && isatool document Test/output";
  2479 
  2480 * theory dependency graph may now be incorporated into documents;
  2481 isatool usedir -g true will produce session_graph.eps/.pdf for use
  2482 with \includegraphics of LaTeX;
  2483 
  2484 * proper spacing of consecutive markup elements, especially text
  2485 blocks after section headings;
  2486 
  2487 * support bold style (for single symbols only), input syntax is like
  2488 this: "\<^bold>\<alpha>" or "\<^bold>A";
  2489 
  2490 * \<bullet> is now output as bold \cdot by default, which looks much
  2491 better in printed text;
  2492 
  2493 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  2494 note that these symbols are currently unavailable in Proof General /
  2495 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  2496 
  2497 * isatool latex no longer depends on changed TEXINPUTS, instead
  2498 isatool document copies the Isabelle style files to the target
  2499 location;
  2500 
  2501 
  2502 *** Isar ***
  2503 
  2504 * Pure/Provers: improved proof by cases and induction;
  2505   - 'case' command admits impromptu naming of parameters (such as
  2506     "case (Suc n)");
  2507   - 'induct' method divinates rule instantiation from the inductive
  2508     claim; no longer requires excessive ?P bindings for proper
  2509     instantiation of cases;
  2510   - 'induct' method properly enumerates all possibilities of set/type
  2511     rules; as a consequence facts may be also passed through *type*
  2512     rules without further ado;
  2513   - 'induct' method now derives symbolic cases from the *rulified*
  2514     rule (before it used to rulify cases stemming from the internal
  2515     atomized version); this means that the context of a non-atomic
  2516     statement becomes is included in the hypothesis, avoiding the
  2517     slightly cumbersome show "PROP ?case" form;
  2518   - 'induct' may now use elim-style induction rules without chaining
  2519     facts, using ``missing'' premises from the goal state; this allows
  2520     rules stemming from inductive sets to be applied in unstructured
  2521     scripts, while still benefitting from proper handling of non-atomic
  2522     statements; NB: major inductive premises need to be put first, all
  2523     the rest of the goal is passed through the induction;
  2524   - 'induct' proper support for mutual induction involving non-atomic
  2525     rule statements (uses the new concept of simultaneous goals, see
  2526     below);
  2527   - append all possible rule selections, but only use the first
  2528     success (no backtracking);
  2529   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  2530   - undeclared rule case names default to numbers 1, 2, 3, ...;
  2531   - added 'print_induct_rules' (covered by help item in recent Proof
  2532     General versions);
  2533   - moved induct/cases attributes to Pure, methods to Provers;
  2534   - generic method setup instantiated for FOL and HOL;
  2535 
  2536 * Pure: support multiple simultaneous goal statements, for example
  2537 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  2538 meta-level mechanism, this acts as if several individual goals had
  2539 been stated separately; in particular common proof methods need to be
  2540 repeated in order to cover all claims; note that a single elimination
  2541 step is *not* sufficient to establish the two conjunctions, so this
  2542 fails:
  2543 
  2544   assume "A & B" then have A and B ..   (*".." fails*)
  2545 
  2546 better use "obtain" in situations as above; alternative refer to
  2547 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  2548 
  2549 * Pure: proper integration with ``locales''; unlike the original
  2550 version by Florian Kammller, Isar locales package high-level proof
  2551 contexts rather than raw logical ones (e.g. we admit to include
  2552 attributes everywhere); operations on locales include merge and
  2553 rename; support for implicit arguments (``structures''); simultaneous
  2554 type-inference over imports and text; see also HOL/ex/Locales.thy for
  2555 some examples;
  2556 
  2557 * Pure: the following commands have been ``localized'', supporting a
  2558 target locale specification "(in name)": 'lemma', 'theorem',
  2559 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  2560 stored both within the locale and at the theory level (exported and
  2561 qualified by the locale name);
  2562 
  2563 * Pure: theory goals may now be specified in ``long'' form, with
  2564 ad-hoc contexts consisting of arbitrary locale elements. for example
  2565 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  2566 definitions may be given, too); the result is a meta-level rule with
  2567 the context elements being discharged in the obvious way;
  2568 
  2569 * Pure: new proof command 'using' allows to augment currently used
  2570 facts after a goal statement ('using' is syntactically analogous to
  2571 'apply', but acts on the goal's facts only); this allows chained facts
  2572 to be separated into parts given before and after a claim, as in
  2573 ``from a and b have C using d and e <proof>'';
  2574 
  2575 * Pure: renamed "antecedent" case to "rule_context";
  2576 
  2577 * Pure: new 'judgment' command records explicit information about the
  2578 object-logic embedding (used by several tools internally); no longer
  2579 use hard-wired "Trueprop";
  2580 
  2581 * Pure: added 'corollary' command;
  2582 
  2583 * Pure: fixed 'token_translation' command;
  2584 
  2585 * Pure: removed obsolete 'exported' attribute;
  2586 
  2587 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  2588 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  2589 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  2590 
  2591 * Pure: method 'atomize' presents local goal premises as object-level
  2592 statements (atomic meta-level propositions); setup controlled via
  2593 rewrite rules declarations of 'atomize' attribute; example
  2594 application: 'induct' method with proper rule statements in improper
  2595 proof *scripts*;
  2596 
  2597 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  2598 now consider the syntactic context of assumptions, giving a better
  2599 chance to get type-inference of the arguments right (this is
  2600 especially important for locales);
  2601 
  2602 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  2603 mode;
  2604 
  2605 * Pure/obtain: the formal conclusion "thesis", being marked as
  2606 ``internal'', may no longer be reference directly in the text;
  2607 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  2608 situations;
  2609 
  2610 * Pure: generic 'sym' attribute which declares a rule both as pure
  2611 'elim?' and for the 'symmetric' operation;
  2612 
  2613 * Pure: marginal comments ``--'' may now occur just anywhere in the
  2614 text; the fixed correlation with particular command syntax has been
  2615 discontinued;
  2616 
  2617 * Pure: new method 'rules' is particularly well-suited for proof
  2618 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  2619 but often produces more compact proof terms with less detours;
  2620 
  2621 * Pure/Provers/classical: simplified integration with pure rule
  2622 attributes and methods; the classical "intro?/elim?/dest?"
  2623 declarations coincide with the pure ones; the "rule" method no longer
  2624 includes classically swapped intros; "intro" and "elim" methods no
  2625 longer pick rules from the context; also got rid of ML declarations
  2626 AddXIs/AddXEs/AddXDs; all of this has some potential for
  2627 INCOMPATIBILITY;
  2628 
  2629 * Provers/classical: attribute 'swapped' produces classical inversions
  2630 of introduction rules;
  2631 
  2632 * Provers/simplifier: 'simplified' attribute may refer to explicit
  2633 rules instead of full simplifier context; 'iff' attribute handles
  2634 conditional rules;
  2635 
  2636 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  2637 
  2638 * HOL: 'recdef' now fails on unfinished automated proofs, use
  2639 "(permissive)" option to recover old behavior;
  2640 
  2641 * HOL: 'inductive' no longer features separate (collective) attributes
  2642 for 'intros' (was found too confusing);
  2643 
  2644 * HOL: properly declared induction rules less_induct and
  2645 wf_induct_rule;
  2646 
  2647 
  2648 *** HOL ***
  2649 
  2650 * HOL: moved over to sane numeral syntax; the new policy is as
  2651 follows:
  2652 
  2653   - 0 and 1 are polymorphic constants, which are defined on any
  2654   numeric type (nat, int, real etc.);
  2655 
  2656   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  2657   binary representation internally;
  2658 
  2659   - type nat has special constructor Suc, and generally prefers Suc 0
  2660   over 1::nat and Suc (Suc 0) over 2::nat;
  2661 
  2662 This change may cause significant problems of INCOMPATIBILITY; here
  2663 are some hints on converting existing sources:
  2664 
  2665   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  2666   entities, so expressions involving "-" (unary or binary minus) need
  2667   to be spaced properly;
  2668 
  2669   - existing occurrences of "1" may need to be constraint "1::nat" or
  2670   even replaced by Suc 0; similar for old "2";
  2671 
  2672   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  2673 
  2674   - remove all special provisions on numerals in proofs;
  2675 
  2676 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  2677 representation (depends on bin_arith_simps in the default context);
  2678 
  2679 * HOL: symbolic syntax for x^2 (numeral 2);
  2680 
  2681 * HOL: the class of all HOL types is now called "type" rather than
  2682 "term"; INCOMPATIBILITY, need to adapt references to this type class
  2683 in axclass/classes, instance/arities, and (usually rare) occurrences
  2684 in typings (of consts etc.); internally the class is called
  2685 "HOL.type", ML programs should refer to HOLogic.typeS;
  2686 
  2687 * HOL/record package improvements:
  2688   - new derived operations "fields" to build a partial record section,
  2689     "extend" to promote a fixed record to a record scheme, and
  2690     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  2691     declared as simp by default;
  2692   - shared operations ("more", "fields", etc.) now need to be always
  2693     qualified) --- potential INCOMPATIBILITY;
  2694   - removed "make_scheme" operations (use "make" with "extend") --
  2695     INCOMPATIBILITY;
  2696   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  2697   - provides cases/induct rules for use with corresponding Isar
  2698     methods (for concrete records, record schemes, concrete more
  2699     parts, and schematic more parts -- in that order);
  2700   - internal definitions directly based on a light-weight abstract
  2701     theory of product types over typedef rather than datatype;
  2702 
  2703 * HOL: generic code generator for generating executable ML code from
  2704 specifications; specific support for HOL constructs such as inductive
  2705 datatypes and sets, as well as recursive functions; can be invoked
  2706 via 'generate_code' theory section;
  2707 
  2708 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  2709 
  2710 * HOL: consolidated and renamed several theories.  In particular:
  2711         Ord.thy has been absorbed into HOL.thy
  2712         String.thy has been absorbed into List.thy
  2713 
  2714 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  2715 (beware of argument permutation!);
  2716 
  2717 * HOL: linorder_less_split superseded by linorder_cases;
  2718 
  2719 * HOL/List: "nodups" renamed to "distinct";
  2720 
  2721 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  2722 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  2723   - Ex_def has changed, now need to use some_eq_ex
  2724 
  2725 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  2726 in this (rare) case use:
  2727 
  2728   delSWrapper "split_all_tac"
  2729   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  2730 
  2731 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  2732 MAY FAIL;
  2733 
  2734 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  2735 Isabelle's type classes, ^ on functions and relations has too general
  2736 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  2737 necessary to attach explicit type constraints;
  2738 
  2739 * HOL/Relation: the prefix name of the infix "O" has been changed from
  2740 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  2741 renamed accordingly (eg "compI" -> "rel_compI").
  2742 
  2743 * HOL: syntax translations now work properly with numerals and records
  2744 expressions;
  2745 
  2746 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  2747 of "lam" -- INCOMPATIBILITY;
  2748 
  2749 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  2750 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  2751 renamed "Product_Type.unit";
  2752 
  2753 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  2754 
  2755 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  2756 the "cases" method);
  2757 
  2758 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  2759 Florian Kammller);
  2760 
  2761 * HOL/IMP: updated and converted to new-style theory format; several
  2762 parts turned into readable document, with proper Isar proof texts and
  2763 some explanations (by Gerwin Klein);
  2764 
  2765 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  2766 
  2767 * HOL-Hyperreal is now a logic image;
  2768 
  2769 
  2770 *** HOLCF ***
  2771 
  2772 * Isar: consts/constdefs supports mixfix syntax for continuous
  2773 operations;
  2774 
  2775 * Isar: domain package adapted to new-style theory format, e.g. see
  2776 HOLCF/ex/Dnat.thy;
  2777 
  2778 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  2779 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  2780 lift.induct_tac, always use UU instead of Undef;
  2781 
  2782 * HOLCF/IMP: updated and converted to new-style theory;
  2783 
  2784 
  2785 *** ZF ***
  2786 
  2787 * Isar: proper integration of logic-specific tools and packages,
  2788 including theory commands '(co)inductive', '(co)datatype',
  2789 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  2790 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  2791 
  2792 * theory Main no longer includes AC; for the Axiom of Choice, base
  2793 your theory on Main_ZFC;
  2794 
  2795 * the integer library now covers quotients and remainders, with many
  2796 laws relating division to addition, multiplication, etc.;
  2797 
  2798 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  2799 typeless version of the formalism;
  2800 
  2801 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  2802 format;
  2803 
  2804 * ZF/Induct: new directory for examples of inductive definitions,
  2805 including theory Multiset for multiset orderings; converted to
  2806 new-style theory format;
  2807 
  2808 * ZF: many new theorems about lists, ordinals, etc.;
  2809 
  2810 
  2811 *** General ***
  2812 
  2813 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  2814 variable proof controls level of detail: 0 = no proofs (only oracle
  2815 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  2816 also ref manual for further ML interfaces;
  2817 
  2818 * Pure/axclass: removed obsolete ML interface
  2819 goal_subclass/goal_arity;
  2820 
  2821 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  2822 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  2823 separate tokens, so expressions involving minus need to be spaced
  2824 properly;
  2825 
  2826 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  2827 rather than "infixl" or "infixr";
  2828 
  2829 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  2830 sort constraint specifications in type inference; e.g. "x::_::foo"
  2831 ensures that the type of "x" is of sort "foo" (but not necessarily a
  2832 type variable);
  2833 
  2834 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  2835 control output of nested => (types); the default behavior is
  2836 "type_brackets";
  2837 
  2838 * Pure/syntax: builtin parse translation for "_constify" turns valued
  2839 tokens into AST constants;
  2840 
  2841 * Pure/syntax: prefer later declarations of translations and print
  2842 translation functions; potential INCOMPATIBILITY: need to reverse
  2843 multiple declarations for same syntax element constant;
  2844 
  2845 * Pure/show_hyps reset by default (in accordance to existing Isar
  2846 practice);
  2847 
  2848 * Provers/classical: renamed addaltern to addafter, addSaltern to
  2849 addSafter;
  2850 
  2851 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  2852 as well;
  2853 
  2854 * system: tested support for MacOS X; should be able to get Isabelle +
  2855 Proof General to work in a plain Terminal after installing Poly/ML
  2856 (e.g. from the Isabelle distribution area) and GNU bash alone
  2857 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  2858 support requires further installations, e.g. from
  2859 http://fink.sourceforge.net/);
  2860 
  2861 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  2862 
  2863 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  2864 of 40 MB), cf. ML_OPTIONS;
  2865 
  2866 * system: Proof General keywords specification is now part of the
  2867 Isabelle distribution (see etc/isar-keywords.el);
  2868 
  2869 * system: support for persistent Proof General sessions (refrain from
  2870 outdating all loaded theories on startup); user may create writable
  2871 logic images like this: ``isabelle -q HOL Test'';
  2872 
  2873 * system: smart selection of Isabelle process versus Isabelle
  2874 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  2875 run both "isabelle" and "Isabelle" even if file names are badly
  2876 damaged (executable inspects the case of the first letter of its own
  2877 name); added separate "isabelle-process" and "isabelle-interface";
  2878 
  2879 * system: refrain from any attempt at filtering input streams; no
  2880 longer support ``8bit'' encoding of old isabelle font, instead proper
  2881 iso-latin characters may now be used; the related isatools
  2882 "symbolinput" and "nonascii" have disappeared as well;
  2883 
  2884 * system: removed old "xterm" interface (the print modes "xterm" and
  2885 "xterm_color" are still available for direct use in a suitable
  2886 terminal);
  2887 
  2888 
  2889 
  2890 New in Isabelle99-2 (February 2001)
  2891 -----------------------------------
  2892 
  2893 *** Overview of INCOMPATIBILITIES ***
  2894 
  2895 * HOL: please note that theories in the Library and elsewhere often use the
  2896 new-style (Isar) format; to refer to their theorems in an ML script you must
  2897 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  2898 
  2899 * HOL: inductive package no longer splits induction rule aggressively,
  2900 but only as far as specified by the introductions given; the old
  2901 format may be recovered via ML function complete_split_rule or attribute
  2902 'split_rule (complete)';
  2903 
  2904 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  2905 gfp_Tarski to gfp_unfold;
  2906 
  2907 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  2908 
  2909 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  2910 relation); infix "^^" has been renamed "``"; infix "``" has been
  2911 renamed "`"; "univalent" has been renamed "single_valued";
  2912 
  2913 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  2914 operation;
  2915 
  2916 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  2917 
  2918 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  2919 
  2920 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  2921 consequence, it is no longer monotonic wrt. the local goal context
  2922 (which is now passed through the inductive cases);
  2923 
  2924 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  2925 \<gg> to \<ggreater>;
  2926 
  2927 
  2928 *** Document preparation ***
  2929 
  2930 * \isabellestyle{NAME} selects version of Isabelle output (currently
  2931 available: are "it" for near math-mode best-style output, "sl" for
  2932 slanted text style, and "tt" for plain type-writer; if no
  2933 \isabellestyle command is given, output is according to slanted
  2934 type-writer);
  2935 
  2936 * support sub/super scripts (for single symbols only), input syntax is
  2937 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  2938 
  2939 * some more standard symbols; see Appendix A of the system manual for
  2940 the complete list of symbols defined in isabellesym.sty;
  2941 
  2942 * improved isabelle style files; more abstract symbol implementation
  2943 (should now use \isamath{...} and \isatext{...} in custom symbol
  2944 definitions);
  2945 
  2946 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  2947 state; Note that presentation of goal states does not conform to
  2948 actual human-readable proof documents.  Please do not include goal
  2949 states into document output unless you really know what you are doing!
  2950 
  2951 * proper indentation of antiquoted output with proportional LaTeX
  2952 fonts;
  2953 
  2954 * no_document ML operator temporarily disables LaTeX document
  2955 generation;
  2956 
  2957 * isatool unsymbolize tunes sources for plain ASCII communication;
  2958 
  2959 
  2960 *** Isar ***
  2961 
  2962 * Pure: Isar now suffers initial goal statements to contain unbound
  2963 schematic variables (this does not conform to actual readable proof
  2964 documents, due to unpredictable outcome and non-compositional proof
  2965 checking); users who know what they are doing may use schematic goals
  2966 for Prolog-style synthesis of proven results;
  2967 
  2968 * Pure: assumption method (an implicit finishing) now handles actual
  2969 rules as well;
  2970 
  2971 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  2972 initial goal, declare "that" only as Pure intro (only for single
  2973 steps); the "that" rule assumption may now be involved in implicit
  2974 finishing, thus ".." becomes a feasible for trivial obtains;
  2975 
  2976 * Pure: default proof step now includes 'intro_classes'; thus trivial
  2977 instance proofs may be performed by "..";
  2978 
  2979 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  2980 statements as well;
  2981 
  2982 * Pure: more robust selection of calculational rules;
  2983 
  2984 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  2985 rule (as well as the assumption rule);
  2986 
  2987 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  2988 lemmas, using the graph browser tool;
  2989 
  2990 * Pure: predict failure of "show" in interactive mode;
  2991 
  2992 * Pure: 'thms_containing' now takes actual terms as arguments;
  2993 
  2994 * HOL: improved method 'induct' --- now handles non-atomic goals
  2995 (potential INCOMPATIBILITY); tuned error handling;
  2996 
  2997 * HOL: cases and induct rules now provide explicit hints about the
  2998 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  2999 any remaining facts are inserted into the goal verbatim;
  3000 
  3001 * HOL: local contexts (aka cases) may now contain term bindings as
  3002 well; the 'cases' and 'induct' methods new provide a ?case binding for
  3003 the result to be shown in each case;
  3004 
  3005 * HOL: added 'recdef_tc' command;
  3006 
  3007 * isatool convert assists in eliminating legacy ML scripts;
  3008 
  3009 
  3010 *** HOL ***
  3011 
  3012 * HOL/Library: a collection of generic theories to be used together
  3013 with main HOL; the theory loader path already includes this directory
  3014 by default; the following existing theories have been moved here:
  3015 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  3016 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  3017 
  3018 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  3019 modelling and verification task performed in Isabelle/HOL +
  3020 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  3021 
  3022 * HOL/Algebra: special summation operator SUM no longer exists, it has
  3023 been replaced by setsum; infix 'assoc' now has priority 50 (like
  3024 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  3025 'domain', this makes the theory consistent with mathematical
  3026 literature;
  3027 
  3028 * HOL basics: added overloaded operations "inverse" and "divide"
  3029 (infix "/"), syntax for generic "abs" operation, generic summation
  3030 operator \<Sum>;
  3031 
  3032 * HOL/typedef: simplified package, provide more useful rules (see also
  3033 HOL/subset.thy);
  3034 
  3035 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  3036 now expressed as a proper nested rule (old-style tactic scripts may
  3037 require atomize_strip_tac to cope with non-atomic premises);
  3038 
  3039 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  3040 to "split_conv" (old name still available for compatibility);
  3041 
  3042 * HOL: improved concrete syntax for strings (e.g. allows translation
  3043 rules with string literals);
  3044 
  3045 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  3046  and Fleuriot's mechanization of analysis, including the transcendental
  3047  functions for the reals;
  3048 
  3049 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  3050 
  3051 
  3052 *** CTT ***
  3053 
  3054 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  3055 "lam" is displayed as TWO lambda-symbols
  3056 
  3057 * CTT: theory Main now available, containing everything (that is, Bool
  3058 and Arith);
  3059 
  3060 
  3061 *** General ***
  3062 
  3063 * Pure: the Simplifier has been implemented properly as a derived rule
  3064 outside of the actual kernel (at last!); the overall performance
  3065 penalty in practical applications is about 50%, while reliability of
  3066 the Isabelle inference kernel has been greatly improved;
  3067 
  3068 * print modes "brackets" and "no_brackets" control output of nested =>
  3069 (types) and ==> (props); the default behaviour is "brackets";
  3070 
  3071 * Provers: fast_tac (and friends) now handle actual object-logic rules
  3072 as assumptions as well;
  3073 
  3074 * system: support Poly/ML 4.0;
  3075 
  3076 * system: isatool install handles KDE version 1 or 2;
  3077 
  3078 
  3079 
  3080 New in Isabelle99-1 (October 2000)
  3081 ----------------------------------
  3082 
  3083 *** Overview of INCOMPATIBILITIES ***
  3084 
  3085 * HOL: simplification of natural numbers is much changed; to partly
  3086 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  3087 issue the following ML commands:
  3088 
  3089   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  3090   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  3091 
  3092 * HOL: simplification no longer dives into case-expressions; this is
  3093 controlled by "t.weak_case_cong" for each datatype t;
  3094 
  3095 * HOL: nat_less_induct renamed to less_induct;
  3096 
  3097 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  3098 fixsome to patch .thy and .ML sources automatically;
  3099 
  3100   select_equality  -> some_equality
  3101   select_eq_Ex     -> some_eq_ex
  3102   selectI2EX       -> someI2_ex
  3103   selectI2         -> someI2
  3104   selectI          -> someI
  3105   select1_equality -> some1_equality
  3106   Eps_sym_eq       -> some_sym_eq_trivial
  3107   Eps_eq           -> some_eq_trivial
  3108 
  3109 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  3110 
  3111 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  3112 instead);
  3113 
  3114 * HOL: the recursion equations generated by 'recdef' are now called
  3115 f.simps instead of f.rules;
  3116 
  3117 * HOL: qed_spec_mp now also handles bounded ALL as well;
  3118 
  3119 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  3120 sometimes be needed;
  3121 
  3122 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  3123 
  3124 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  3125 
  3126 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  3127 product is now "<*>" instead of "Times"; the lexicographic product is
  3128 now "<*lex*>" instead of "**";
  3129 
  3130 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  3131 of main HOL, but was unused); better use HOL's datatype package;
  3132 
  3133 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  3134 the old syntax may be recovered as follows:
  3135 
  3136   syntax (symbols)
  3137     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  3138       (infixl "\\<oplus>" 100)
  3139 
  3140 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3141 
  3142 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  3143 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  3144 internally;
  3145 
  3146 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  3147 changed from A/r to A//r;
  3148 
  3149 * ZF: new treatment of arithmetic (nat & int) may break some old
  3150 proofs;
  3151 
  3152 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  3153 rulify -> rule_format, elimify -> elim_format, ...);
  3154 
  3155 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3156 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  3157 should have to change intro!! to intro? only); replaced "delrule" by
  3158 "rule del";
  3159 
  3160 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  3161 
  3162 * Provers: strengthened force_tac by using new first_best_tac;
  3163 
  3164 * LaTeX document preparation: several changes of isabelle.sty (see
  3165 lib/texinputs);
  3166 
  3167 
  3168 *** Document preparation ***
  3169 
  3170 * formal comments (text blocks etc.) in new-style theories may now
  3171 contain antiquotations of thm/prop/term/typ/text to be presented
  3172 according to latex print mode; concrete syntax is like this:
  3173 @{term[show_types] "f(x) = a + x"};
  3174 
  3175 * isatool mkdir provides easy setup of Isabelle session directories,
  3176 including proper document sources;
  3177 
  3178 * generated LaTeX sources are now deleted after successful run
  3179 (isatool document -c); may retain a copy somewhere else via -D option
  3180 of isatool usedir;
  3181 
  3182 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  3183 style files, achieving self-contained LaTeX sources and simplifying
  3184 LaTeX debugging;
  3185 
  3186 * old-style theories now produce (crude) LaTeX output as well;
  3187 
  3188 * browser info session directories are now self-contained (may be put
  3189 on WWW server seperately); improved graphs of nested sessions; removed
  3190 graph for 'all sessions';
  3191 
  3192 * several improvements in isabelle style files; \isabellestyle{it}
  3193 produces fake math mode output; \isamarkupheader is now \section by
  3194 default; see lib/texinputs/isabelle.sty etc.;
  3195 
  3196 
  3197 *** Isar ***
  3198 
  3199 * Isar/Pure: local results and corresponding term bindings are now
  3200 subject to Hindley-Milner polymorphism (similar to ML); this
  3201 accommodates incremental type-inference very nicely;
  3202 
  3203 * Isar/Pure: new derived language element 'obtain' supports
  3204 generalized existence reasoning;
  3205 
  3206 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  3207 support accumulation of results, without applying any rules yet;
  3208 useful to collect intermediate results without explicit name
  3209 references, and for use with transitivity rules with more than 2
  3210 premises;
  3211 
  3212 * Isar/Pure: scalable support for case-analysis type proofs: new
  3213 'case' language element refers to local contexts symbolically, as
  3214 produced by certain proof methods; internally, case names are attached
  3215 to theorems as "tags";
  3216 
  3217 * Isar/Pure: theory command 'hide' removes declarations from
  3218 class/type/const name spaces;
  3219 
  3220 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  3221 indicate potential overloading;
  3222 
  3223 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  3224 
  3225 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  3226 "{a,b,c}" instead of {a,b,c};
  3227 
  3228 * Isar/Pure now provides its own version of intro/elim/dest
  3229 attributes; useful for building new logics, but beware of confusion
  3230 with the version in Provers/classical;
  3231 
  3232 * Isar/Pure: the local context of (non-atomic) goals is provided via
  3233 case name 'antecedent';
  3234 
  3235 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  3236 to the current context is now done automatically);
  3237 
  3238 * Isar/Pure: theory command 'method_setup' provides a simple interface
  3239 for definining proof methods in ML;
  3240 
  3241 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3242 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  3243 most cases, one should have to change intro!! to intro? only);
  3244 replaced "delrule" by "rule del";
  3245 
  3246 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  3247 'symmetric' attribute (the latter supercedes [RS sym]);
  3248 
  3249 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  3250 method modifier); 'simp' method: 'only:' modifier removes loopers as
  3251 well (including splits);
  3252 
  3253 * Isar/Provers: Simplifier and Classical methods now support all kind
  3254 of modifiers used in the past, including 'cong', 'iff', etc.
  3255 
  3256 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  3257 of Simplifier and Classical reasoner);
  3258 
  3259 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  3260 now support named cases; major packages (inductive, datatype, primrec,
  3261 recdef) support case names and properly name parameters;
  3262 
  3263 * Isar/HOL: new transitivity rules for substitution in inequalities --
  3264 monotonicity conditions are extracted to be proven at end of
  3265 calculations;
  3266 
  3267 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  3268 method anyway;
  3269 
  3270 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  3271 split_if split_if_asm; datatype package provides theorems foo.splits =
  3272 foo.split foo.split_asm for each datatype;
  3273 
  3274 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  3275 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  3276 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  3277 use "(cases (simplified))" method in proper proof texts);
  3278 
  3279 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  3280 
  3281 * Isar: names of theorems etc. may be natural numbers as well;
  3282 
  3283 * Isar: 'pr' command: optional arguments for goals_limit and
  3284 ProofContext.prems_limit; no longer prints theory contexts, but only
  3285 proof states;
  3286 
  3287 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  3288 additional print modes to be specified; e.g. "pr(latex)" will print
  3289 proof state according to the Isabelle LaTeX style;
  3290 
  3291 * Isar: improved support for emulating tactic scripts, including proof
  3292 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  3293 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  3294 (for HOL datatypes);
  3295 
  3296 * Isar: simplified (more robust) goal selection of proof methods: 1st
  3297 goal, all goals, or explicit goal specifier (tactic emulation); thus
  3298 'proof method scripts' have to be in depth-first order;
  3299 
  3300 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  3301 
  3302 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  3303 should instead use individual commands for printing items
  3304 (print_commands, print_methods etc.);
  3305 
  3306 * Isar: added 'nothing' --- the empty list of theorems;
  3307 
  3308 
  3309 *** HOL ***
  3310 
  3311 * HOL/MicroJava: formalization of a fragment of Java, together with a
  3312 corresponding virtual machine and a specification of its bytecode
  3313 verifier and a lightweight bytecode verifier, including proofs of
  3314 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  3315 Cornelia Pusch (see also the homepage of project Bali at
  3316 http://isabelle.in.tum.de/Bali/);
  3317 
  3318 * HOL/Algebra: new theory of rings and univariate polynomials, by
  3319 Clemens Ballarin;
  3320 
  3321 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  3322 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  3323 Rasmussen;
  3324 
  3325 * HOL/Lattice: fundamental concepts of lattice theory and order
  3326 structures, including duals, properties of bounds versus algebraic
  3327 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  3328 Theorem for complete lattices etc.; may also serve as a demonstration
  3329 for abstract algebraic reasoning using axiomatic type classes, and
  3330 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  3331 
  3332 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  3333 von Oheimb;
  3334 
  3335 * HOL/IMPP: extension of IMP with local variables and mutually
  3336 recursive procedures, by David von Oheimb;
  3337 
  3338 * HOL/Lambda: converted into new-style theory and document;
  3339 
  3340 * HOL/ex/Multiquote: example of multiple nested quotations and
  3341 anti-quotations -- basically a generalized version of de-Bruijn
  3342 representation; very useful in avoiding lifting of operations;
  3343 
  3344 * HOL/record: added general record equality rule to simpset; fixed
  3345 select-update simplification procedure to handle extended records as
  3346 well; admit "r" as field name;
  3347 
  3348 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  3349 other numeric types and also as the identity of groups, rings, etc.;
  3350 
  3351 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  3352 Types nat and int belong to this axclass;
  3353 
  3354 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  3355    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  3356    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  3357   two terms #m*u and #n*u are replaced by #(m+n)*u
  3358     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  3359   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  3360     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  3361 
  3362 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  3363 powerful prover for predicate logic but knows nothing of clasets; see
  3364 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  3365 
  3366 * HOL: new version of "case_tac" subsumes both boolean case split and
  3367 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  3368 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  3369 
  3370 * HOL: simplification no longer dives into case-expressions: only the
  3371 selector expression is simplified, but not the remaining arms; to
  3372 enable full simplification of case-expressions for datatype t, you may
  3373 remove t.weak_case_cong from the simpset, either globally (Delcongs
  3374 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  3375 
  3376 * HOL/recdef: the recursion equations generated by 'recdef' for
  3377 function 'f' are now called f.simps instead of f.rules; if all
  3378 termination conditions are proved automatically, these simplification
  3379 rules are added to the simpset, as in primrec; rules may be named
  3380 individually as well, resulting in a separate list of theorems for
  3381 each equation;
  3382 
  3383 * HOL/While is a new theory that provides a while-combinator. It
  3384 permits the definition of tail-recursive functions without the
  3385 provision of a termination measure. The latter is necessary once the
  3386 invariant proof rule for while is applied.
  3387 
  3388 * HOL: new (overloaded) notation for the set of elements below/above
  3389 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  3390 
  3391 * HOL: theorems impI, allI, ballI bound as "strip";
  3392 
  3393 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  3394 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  3395 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  3396 
  3397 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3398 
  3399 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  3400 main HOL, but was unused);
  3401 
  3402 * HOL: fewer consts declared as global (e.g. have to refer to
  3403 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  3404 
  3405 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  3406 in case of overlap with user translations (e.g. judgements over
  3407 tuples); (note that the underlying logical represenation is still
  3408 bogus);
  3409 
  3410 
  3411 *** ZF ***
  3412 
  3413 * ZF: simplification automatically cancels common terms in arithmetic
  3414 expressions over nat and int;
  3415 
  3416 * ZF: new treatment of nat to minimize type-checking: all operators
  3417 coerce their operands to a natural number using the function natify,
  3418 making the algebraic laws unconditional;
  3419 
  3420 * ZF: as above, for int: operators coerce their operands to an integer
  3421 using the function intify;
  3422 
  3423 * ZF: the integer library now contains many of the usual laws for the
  3424 orderings, including $<=, and monotonicity laws for $+ and $*;
  3425 
  3426 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  3427 simplification;
  3428 
  3429 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  3430 to the simplifier and classical reasoner simultaneously;
  3431 
  3432 
  3433 *** General ***
  3434 
  3435 * Provers: blast_tac now handles actual object-logic rules as
  3436 assumptions; note that auto_tac uses blast_tac internally as well;
  3437 
  3438 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  3439 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  3440 
  3441 * Provers: delrules now handles destruct rules as well (no longer need
  3442 explicit make_elim);
  3443 
  3444 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  3445   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3446 use instead the strong form,
  3447   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3448 in HOL, FOL and ZF the function cla_make_elim will create such rules
  3449 from destruct-rules;
  3450 
  3451 * Provers: Simplifier.easy_setup provides a fast path to basic
  3452 Simplifier setup for new object-logics;
  3453 
  3454 * Pure: AST translation rules no longer require constant head on LHS;
  3455 
  3456 * Pure: improved name spaces: ambiguous output is qualified; support
  3457 for hiding of names;
  3458 
  3459 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  3460 XSYMBOL_HOME; no longer need to do manual configuration in most
  3461 situations;
  3462 
  3463 * system: compression of ML heaps images may now be controlled via -c
  3464 option of isabelle and isatool usedir (currently only observed by
  3465 Poly/ML);
  3466 
  3467 * system: isatool installfonts may handle X-Symbol fonts as well (very
  3468 useful for remote X11);
  3469 
  3470 * system: provide TAGS file for Isabelle sources;
  3471 
  3472 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  3473 order;
  3474 
  3475 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  3476 timing flag supersedes proof_timing and Toplevel.trace;
  3477 
  3478 * ML: new combinators |>> and |>>> for incremental transformations
  3479 with secondary results (e.g. certain theory extensions):
  3480 
  3481 * ML: PureThy.add_defs gets additional argument to indicate potential
  3482 overloading (usually false);
  3483 
  3484 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  3485 results;
  3486 
  3487 
  3488 
  3489 New in Isabelle99 (October 1999)
  3490 --------------------------------
  3491 
  3492 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3493 
  3494 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  3495 are no longer simplified.  (This allows the simplifier to unfold recursive
  3496 functional programs.)  To restore the old behaviour, declare
  3497 
  3498     Delcongs [if_weak_cong];
  3499 
  3500 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  3501 complement;
  3502 
  3503 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  3504 
  3505 * HOL/datatype: mutual_induct_tac no longer exists --
  3506   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  3507 
  3508 * HOL/typedef: fixed type inference for representing set; type
  3509 arguments now have to occur explicitly on the rhs as type constraints;
  3510 
  3511 * ZF: The con_defs part of an inductive definition may no longer refer
  3512 to constants declared in the same theory;
  3513 
  3514 * HOL, ZF: the function mk_cases, generated by the inductive
  3515 definition package, has lost an argument.  To simplify its result, it
  3516 uses the default simpset instead of a supplied list of theorems.
  3517 
  3518 * HOL/List: the constructors of type list are now Nil and Cons;
  3519 
  3520 * Simplifier: the type of the infix ML functions
  3521         setSSolver addSSolver setSolver addSolver
  3522 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  3523 for packaging solvers. A solver is created via
  3524         mk_solver: string -> (thm list -> int -> tactic) -> solver
  3525 where the string argument is only a comment.
  3526 
  3527 
  3528 *** Proof tools ***
  3529 
  3530 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  3531 decision procedure for linear arithmetic. Currently it is used for
  3532 types `nat', `int', and `real' in HOL (see below); it can, should and
  3533 will be instantiated for other types and logics as well.
  3534 
  3535 * The simplifier now accepts rewrite rules with flexible heads, eg
  3536      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  3537   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  3538   matching.
  3539 
  3540 
  3541 *** General ***
  3542 
  3543 * New Isabelle/Isar subsystem provides an alternative to traditional
  3544 tactical theorem proving; together with the ProofGeneral/isar user
  3545 interface it offers an interactive environment for developing human
  3546 readable proof documents (Isar == Intelligible semi-automated
  3547 reasoning); for further information see isatool doc isar-ref,
  3548 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  3549 
  3550 * improved and simplified presentation of theories: better HTML markup
  3551 (including colors), graph views in several sizes; isatool usedir now
  3552 provides a proper interface for user theories (via -P option); actual
  3553 document preparation based on (PDF)LaTeX is available as well (for
  3554 new-style theories only); see isatool doc system for more information;
  3555 
  3556 * native support for Proof General, both for classic Isabelle and
  3557 Isabelle/Isar;
  3558 
  3559 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  3560 using the graph browser tool;
  3561 
  3562 * Isabelle manuals now also available as PDF;
  3563 
  3564 * theory loader rewritten from scratch (may not be fully
  3565 bug-compatible); old loadpath variable has been replaced by show_path,
  3566 add_path, del_path, reset_path functions; new operations such as
  3567 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  3568 isatool doc ref);
  3569 
  3570 * improved isatool install: option -k creates KDE application icon,
  3571 option -p DIR installs standalone binaries;
  3572 
  3573 * added ML_PLATFORM setting (useful for cross-platform installations);
  3574 more robust handling of platform specific ML images for SML/NJ;
  3575 
  3576 * the settings environment is now statically scoped, i.e. it is never
  3577 created again in sub-processes invoked from isabelle, isatool, or
  3578 Isabelle;
  3579 
  3580 * path element specification '~~' refers to '$ISABELLE_HOME';
  3581 
  3582 * in locales, the "assumes" and "defines" parts may be omitted if
  3583 empty;
  3584 
  3585 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  3586 long arrows);
  3587 
  3588 * new print_mode "HTML";
  3589 
  3590 * new flag show_tags controls display of tags of theorems (which are
  3591 basically just comments that may be attached by some tools);
  3592 
  3593 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  3594 mode and goal output format:
  3595 
  3596 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  3597 244c244
  3598 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  3599 ---
  3600 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  3601 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  3602 181c181
  3603 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  3604 ---
  3605 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  3606 
  3607 * function bind_thms stores lists of theorems (cf. bind_thm);
  3608 
  3609 * new shorthand tactics ftac, eatac, datac, fatac;
  3610 
  3611 * qed (and friends) now accept "" as result name; in that case the
  3612 theorem is not stored, but proper checks and presentation of the
  3613 result still apply;
  3614 
  3615 * theorem database now also indexes constants "Trueprop", "all",
  3616 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  3617 
  3618 
  3619 *** HOL ***
  3620 
  3621 ** HOL arithmetic **
  3622 
  3623 * There are now decision procedures for linear arithmetic over nat and
  3624 int:
  3625 
  3626 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  3627 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  3628 are treated as atomic; subformulae not involving type `nat' or `int'
  3629 are ignored; quantified subformulae are ignored unless they are
  3630 positive universal or negative existential. The tactic has to be
  3631 invoked by hand and can be a little bit slow. In particular, the
  3632 running time is exponential in the number of occurrences of `min' and
  3633 `max', and `-' on `nat'.
  3634 
  3635 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  3636 (negated) (in)equalities among the premises and the conclusion into
  3637 account (i.e. no compound formulae) and does not know about `min' and
  3638 `max', and `-' on `nat'. It is fast and is used automatically by the
  3639 simplifier.
  3640 
  3641 NB: At the moment, these decision procedures do not cope with mixed
  3642 nat/int formulae where the two parts interact, such as `m < n ==>
  3643 int(m) < int(n)'.
  3644 
  3645 * HOL/Numeral provides a generic theory of numerals (encoded
  3646 efficiently as bit strings); setup for types nat/int/real is in place;
  3647 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  3648 int, existing theories and proof scripts may require a few additional
  3649 type constraints;
  3650 
  3651 * integer division and remainder can now be performed on constant
  3652 arguments;
  3653 
  3654 * many properties of integer multiplication, division and remainder
  3655 are now available;
  3656 
  3657 * An interface to the Stanford Validity Checker (SVC) is available through the
  3658 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  3659 are proved automatically.  SVC must be installed separately, and its results
  3660 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  3661 invocation of the underlying oracle).  For SVC see
  3662   http://verify.stanford.edu/SVC
  3663 
  3664 * IsaMakefile: the HOL-Real target now builds an actual image;
  3665 
  3666 
  3667 ** HOL misc **
  3668 
  3669 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  3670 (in Isabelle/Isar) -- by Gertrud Bauer;
  3671 
  3672 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  3673 analysis for assembly languages with subtypes;
  3674 
  3675 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  3676 -- avoids syntactic ambiguities and treats state, transition, and
  3677 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  3678 changed syntax and (many) tactics;
  3679 
  3680 * HOL/inductive: Now also handles more general introduction rules such
  3681   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  3682   theorems are now maintained within the theory (maintained via the
  3683   "mono" attribute);
  3684 
  3685 * HOL/datatype: Now also handles arbitrarily branching datatypes
  3686   (using function types) such as
  3687 
  3688   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  3689 
  3690 * HOL/record: record_simproc (part of the default simpset) takes care
  3691 of selectors applied to updated records; record_split_tac is no longer
  3692 part of the default claset; update_defs may now be removed from the
  3693 simpset in many cases; COMPATIBILITY: old behavior achieved by
  3694 
  3695   claset_ref () := claset() addSWrapper record_split_wrapper;
  3696   Delsimprocs [record_simproc]
  3697 
  3698 * HOL/typedef: fixed type inference for representing set; type
  3699 arguments now have to occur explicitly on the rhs as type constraints;
  3700 
  3701 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  3702 names rather than an ML expression;
  3703 
  3704 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  3705 supplied later.  Program schemes can be defined, such as
  3706     "While B C s = (if B s then While B C (C s) else s)"
  3707 where the well-founded relation can be chosen after B and C have been given.
  3708 
  3709 * HOL/List: the constructors of type list are now Nil and Cons;
  3710 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  3711 course, ML tools referring to List.list.op # etc. have to be adapted;
  3712 
  3713 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  3714 disabled by default; run isabelle with option -m HOL to get back to
  3715 the original Gordon/HOL-style output;
  3716 
  3717 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  3718 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  3719 
  3720 * HOL basic syntax simplified (more orthogonal): all variants of
  3721 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  3722 Eps operator is provided as well: "SOME x. P[x]";
  3723 
  3724 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  3725 
  3726 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  3727 thus available for user theories;
  3728 
  3729 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  3730 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  3731 time;
  3732 
  3733 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  3734 several times and then mp;
  3735 
  3736 
  3737 *** LK ***
  3738 
  3739 * the notation <<...>> is now available as a notation for sequences of
  3740 formulas;
  3741 
  3742 * the simplifier is now installed
  3743 
  3744 * the axiom system has been generalized (thanks to Soren Heilmann)
  3745 
  3746 * the classical reasoner now has a default rule database
  3747 
  3748 
  3749 *** ZF ***
  3750 
  3751 * new primrec section allows primitive recursive functions to be given
  3752 directly (as in HOL) over datatypes and the natural numbers;
  3753 
  3754 * new tactics induct_tac and exhaust_tac for induction (or case
  3755 analysis) over datatypes and the natural numbers;
  3756 
  3757 * the datatype declaration of type T now defines the recursor T_rec;
  3758 
  3759 * simplification automatically does freeness reasoning for datatype
  3760 constructors;
  3761 
  3762 * automatic type-inference, with AddTCs command to insert new
  3763 type-checking rules;
  3764 
  3765 * datatype introduction rules are now added as Safe Introduction rules
  3766 to the claset;
  3767 
  3768 * the syntax "if P then x else y" is now available in addition to
  3769 if(P,x,y);
  3770 
  3771 
  3772 *** Internal programming interfaces ***
  3773 
  3774 * tuned simplifier trace output; new flag debug_simp;
  3775 
  3776 * structures Vartab / Termtab (instances of TableFun) offer efficient
  3777 tables indexed by indexname_ord / term_ord (compatible with aconv);
  3778 
  3779 * AxClass.axclass_tac lost the theory argument;
  3780 
  3781 * tuned current_goals_markers semantics: begin / end goal avoids
  3782 printing empty lines;
  3783 
  3784 * removed prs and prs_fn hook, which was broken because it did not
  3785 include \n in its semantics, forcing writeln to add one
  3786 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  3787 string -> unit if you really want to output text without newline;
  3788 
  3789 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  3790 plain output, interface builders may have to enable 'isabelle_font'
  3791 mode to get Isabelle font glyphs as before;
  3792 
  3793 * refined token_translation interface; INCOMPATIBILITY: output length
  3794 now of type real instead of int;
  3795 
  3796 * theory loader actions may be traced via new ThyInfo.add_hook
  3797 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  3798 your own database of information attached to *whole* theories -- as
  3799 opposed to intra-theory data slots offered via TheoryDataFun;
  3800 
  3801 * proper handling of dangling sort hypotheses (at last!);
  3802 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  3803 extra sort hypotheses that can be witnessed from the type signature;
  3804 the force_strip_shyps flag is gone, any remaining shyps are simply
  3805 left in the theorem (with a warning issued by strip_shyps_warning);
  3806 
  3807 
  3808 
  3809 New in Isabelle98-1 (October 1998)
  3810 ----------------------------------
  3811 
  3812 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3813 
  3814 * several changes of automated proof tools;
  3815 
  3816 * HOL: major changes to the inductive and datatype packages, including
  3817 some minor incompatibilities of theory syntax;
  3818 
  3819 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  3820 called `inj_on';
  3821 
  3822 * HOL: removed duplicate thms in Arith:
  3823   less_imp_add_less  should be replaced by  trans_less_add1
  3824   le_imp_add_le      should be replaced by  trans_le_add1
  3825 
  3826 * HOL: unary minus is now overloaded (new type constraints may be
  3827 required);
  3828 
  3829 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  3830 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  3831 now taken as an integer constant.
  3832 
  3833 * Pure: ML function 'theory_of' renamed to 'theory';
  3834 
  3835 
  3836 *** Proof tools ***
  3837 
  3838 * Simplifier:
  3839   1. Asm_full_simp_tac is now more aggressive.
  3840      1. It will sometimes reorient premises if that increases their power to
  3841         simplify.
  3842      2. It does no longer proceed strictly from left to right but may also
  3843         rotate premises to achieve further simplification.
  3844      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  3845      old Asm_full_simp_tac in that it does not rotate premises.
  3846   2. The simplifier now knows a little bit about nat-arithmetic.
  3847 
  3848 * Classical reasoner: wrapper mechanism for the classical reasoner now
  3849 allows for selected deletion of wrappers, by introduction of names for
  3850 wrapper functionals.  This implies that addbefore, addSbefore,
  3851 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  3852 and that adding two tactics with the same name overwrites the first
  3853 one (emitting a warning).
  3854   type wrapper = (int -> tactic) -> (int -> tactic)
  3855   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  3856   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  3857   delWrapper, delSWrapper: claset *  string            -> claset
  3858   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  3859 
  3860 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  3861 semantics; addbefore now affects only the unsafe part of step_tac
  3862 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  3863 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  3864 by Force_tac;
  3865 
  3866 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  3867 compWrapper; added safe wrapper (and access functions for it);
  3868 
  3869 * HOL/split_all_tac is now much faster and fails if there is nothing
  3870 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  3871 and the names of the automatically generated variables have changed.
  3872 split_all_tac has moved within claset() from unsafe wrappers to safe
  3873 wrappers, which means that !!-bound variables are split much more
  3874 aggressively, and safe_tac and clarify_tac now split such variables.
  3875 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  3876 Note: the same holds for record_split_tac, which does the job of
  3877 split_all_tac for record fields.
  3878 
  3879 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  3880 permanently to the default simpset using Addsplits just like
  3881 Addsimps. They can be removed via Delsplits just like
  3882 Delsimps. Lower-case versions are also available.
  3883 
  3884 * HOL/Simplifier: The rule split_if is now part of the default
  3885 simpset. This means that the simplifier will eliminate all occurrences
  3886 of if-then-else in the conclusion of a goal. To prevent this, you can
  3887 either remove split_if completely from the default simpset by
  3888 `Delsplits [split_if]' or remove it in a specific call of the
  3889 simplifier using `... delsplits [split_if]'.  You can also add/delete
  3890 other case splitting rules to/from the default simpset: every datatype
  3891 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  3892 t is the name of the datatype).
  3893 
  3894 * Classical reasoner / Simplifier combination: new force_tac (and
  3895 derivatives Force_tac, force) combines rewriting and classical
  3896 reasoning (and whatever other tools) similarly to auto_tac, but is
  3897 aimed to solve the given subgoal completely.
  3898 
  3899 
  3900 *** General ***
  3901 
  3902 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  3903 and `goalw': the theory is no longer needed as an explicit argument -
  3904 the current theory context is used; assumptions are no longer returned
  3905 at the ML-level unless one of them starts with ==> or !!; it is
  3906 recommended to convert to these new commands using isatool fixgoal
  3907 (backup your sources first!);
  3908 
  3909 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  3910 the current theory context, and 'theory' to lookup stored theories;
  3911 
  3912 * new theory section 'locale' for declaring constants, assumptions and
  3913 definitions that have local scope;
  3914 
  3915 * new theory section 'nonterminals' for purely syntactic types;
  3916 
  3917 * new theory section 'setup' for generic ML setup functions
  3918 (e.g. package initialization);
  3919 
  3920 * the distribution now includes Isabelle icons: see
  3921 lib/logo/isabelle-{small,tiny}.xpm;
  3922 
  3923 * isatool install - install binaries with absolute references to
  3924 ISABELLE_HOME/bin;
  3925 
  3926 * isatool logo -- create instances of the Isabelle logo (as EPS);
  3927 
  3928 * print mode 'emacs' reserved for Isamode;
  3929 
  3930 * support multiple print (ast) translations per constant name;
  3931 
  3932 * theorems involving oracles are now printed with a suffixed [!];
  3933 
  3934 
  3935 *** HOL ***
  3936 
  3937 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  3938 
  3939 * HOL/inductive package reorganized and improved: now supports mutual
  3940 definitions such as
  3941 
  3942   inductive EVEN ODD
  3943     intrs
  3944       null "0 : EVEN"
  3945       oddI "n : EVEN ==> Suc n : ODD"
  3946       evenI "n : ODD ==> Suc n : EVEN"
  3947 
  3948 new theorem list "elims" contains an elimination rule for each of the
  3949 recursive sets; inductive definitions now handle disjunctive premises
  3950 correctly (also ZF);
  3951 
  3952 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  3953 "mutual_induct" no longer exists - the induction rule is always
  3954 contained in "induct";
  3955 
  3956 
  3957 * HOL/datatype package re-implemented and greatly improved: now
  3958 supports mutually recursive datatypes such as
  3959 
  3960   datatype
  3961     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  3962             | SUM ('a aexp) ('a aexp)
  3963             | DIFF ('a aexp) ('a aexp)
  3964             | NUM 'a
  3965   and
  3966     'a bexp = LESS ('a aexp) ('a aexp)
  3967             | AND ('a bexp) ('a bexp)
  3968             | OR ('a bexp) ('a bexp)
  3969 
  3970 as well as indirectly recursive datatypes such as
  3971 
  3972   datatype
  3973     ('a, 'b) term = Var 'a
  3974                   | App 'b ((('a, 'b) term) list)
  3975 
  3976 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  3977 induction on mutually / indirectly recursive datatypes.
  3978 
  3979 Primrec equations are now stored in theory and can be accessed via
  3980 <function_name>.simps.
  3981 
  3982 INCOMPATIBILITIES:
  3983 
  3984   - Theories using datatypes must now have theory Datatype as an
  3985     ancestor.
  3986   - The specific <typename>.induct_tac no longer exists - use the
  3987     generic induct_tac instead.
  3988   - natE has been renamed to nat.exhaust - use exhaust_tac
  3989     instead of res_inst_tac ... natE. Note that the variable
  3990     names in nat.exhaust differ from the names in natE, this
  3991     may cause some "fragile" proofs to fail.
  3992   - The theorems split_<typename>_case and split_<typename>_case_asm
  3993     have been renamed to <typename>.split and <typename>.split_asm.
  3994   - Since default sorts of type variables are now handled correctly,
  3995     some datatype definitions may have to be annotated with explicit
  3996     sort constraints.
  3997   - Primrec definitions no longer require function name and type
  3998     of recursive argument.
  3999 
  4000 Consider using isatool fixdatatype to adapt your theories and proof
  4001 scripts to the new package (backup your sources first!).
  4002 
  4003 
  4004 * HOL/record package: considerably improved implementation; now
  4005 includes concrete syntax for record types, terms, updates; theorems
  4006 for surjective pairing and splitting !!-bound record variables; proof
  4007 support is as follows:
  4008 
  4009   1) standard conversions (selectors or updates applied to record
  4010 constructor terms) are part of the standard simpset;
  4011 
  4012   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  4013 made part of standard simpset and claset via addIffs;
  4014 
  4015   3) a tactic for record field splitting (record_split_tac) is part of
  4016 the standard claset (addSWrapper);
  4017 
  4018 To get a better idea about these rules you may retrieve them via
  4019 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  4020 the name of your record type.
  4021 
  4022 The split tactic 3) conceptually simplifies by the following rule:
  4023 
  4024   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  4025 
  4026 Thus any record variable that is bound by meta-all will automatically
  4027 blow up into some record constructor term, consequently the
  4028 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  4029 solve record problems automatically.
  4030 
  4031 
  4032 * reorganized the main HOL image: HOL/Integ and String loaded by
  4033 default; theory Main includes everything;
  4034 
  4035 * automatic simplification of integer sums and comparisons, using cancellation;
  4036 
  4037 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  4038 
  4039 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  4040 
  4041 * many new identities for unions, intersections, set difference, etc.;
  4042 
  4043 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  4044 called split_if, split_split, split_sum_case and split_nat_case (to go
  4045 with add/delsplits);
  4046 
  4047 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  4048 (?x::unit) = (); this is made part of the default simpset, which COULD
  4049 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  4050 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  4051 unit_abs_eta_conv is added in order to counter the effect of
  4052 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  4053 %u.f();
  4054 
  4055 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  4056 makes more sense);
  4057 
  4058 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4059   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4060   disjointness reasoning but breaking a few old proofs.
  4061 
  4062 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  4063 to 'converse' from 'inverse' (for compatibility with ZF and some
  4064 literature);
  4065 
  4066 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  4067 the well-founded relation;
  4068 
  4069 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  4070     Compl A.  The "Compl" syntax remains available as input syntax for this
  4071     release ONLY.
  4072 
  4073 * HOL/Update: new theory of function updates:
  4074     f(a:=b) == %x. if x=a then b else f x
  4075 may also be iterated as in f(a:=b,c:=d,...);
  4076 
  4077 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  4078 
  4079 * HOL/List:
  4080   - new function list_update written xs[i:=v] that updates the i-th
  4081     list position. May also be iterated as in xs[i:=a,j:=b,...].
  4082   - new function `upt' written [i..j(] which generates the list
  4083     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  4084     bound write [i..j], which is a shorthand for [i..j+1(].
  4085   - new lexicographic orderings and corresponding wellfoundedness theorems.
  4086 
  4087 * HOL/Arith:
  4088   - removed 'pred' (predecessor) function;
  4089   - generalized some theorems about n-1;
  4090   - many new laws about "div" and "mod";
  4091   - new laws about greatest common divisors (see theory ex/Primes);
  4092 
  4093 * HOL/Relation: renamed the relational operator r^-1 "converse"
  4094 instead of "inverse";
  4095 
  4096 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  4097   of the multiset ordering;
  4098 
  4099 * directory HOL/Real: a construction of the reals using Dedekind cuts
  4100   (not included by default);
  4101 
  4102 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  4103 
  4104 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  4105   programs, i.e. different program variables may have different types.
  4106 
  4107 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4108   [previously, this check worked only if the rewrite rule was unconditional]
  4109   Now rew can involve either definitions or equalities (either == or =).
  4110 
  4111 
  4112 *** ZF ***
  4113 
  4114 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  4115   only the theorems proved on ZF.ML;
  4116 
  4117 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4118   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4119   disjointness reasoning but breaking a few old proofs.
  4120 
  4121 * ZF/Update: new theory of function updates
  4122     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  4123   may also be iterated as in f(a:=b,c:=d,...);
  4124 
  4125 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  4126 
  4127 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4128   [previously, this check worked only if the rewrite rule was unconditional]
  4129   Now rew can involve either definitions or equalities (either == or =).
  4130 
  4131 * case_tac provided for compatibility with HOL
  4132     (like the old excluded_middle_tac, but with subgoals swapped)
  4133 
  4134 
  4135 *** Internal programming interfaces ***
  4136 
  4137 * Pure: several new basic modules made available for general use, see
  4138 also src/Pure/README;
  4139 
  4140 * improved the theory data mechanism to support encapsulation (data
  4141 kind name replaced by private Object.kind, acting as authorization
  4142 key); new type-safe user interface via functor TheoryDataFun; generic
  4143 print_data function becomes basically useless;
  4144 
  4145 * removed global_names compatibility flag -- all theory declarations
  4146 are qualified by default;
  4147 
  4148 * module Pure/Syntax now offers quote / antiquote translation
  4149 functions (useful for Hoare logic etc. with implicit dependencies);
  4150 see HOL/ex/Antiquote for an example use;
  4151 
  4152 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  4153 cterm -> thm;
  4154 
  4155 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  4156 subgoal;
  4157 
  4158 * Display.print_goals function moved to Locale.print_goals;
  4159 
  4160 * standard print function for goals supports current_goals_markers
  4161 variable for marking begin of proof, end of proof, start of goal; the
  4162 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  4163 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  4164 for example;
  4165 
  4166 
  4167 
  4168 New in Isabelle98 (January 1998)
  4169 --------------------------------
  4170 
  4171 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4172 
  4173 * changed lexical syntax of terms / types: dots made part of long
  4174 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  4175 
  4176 * simpset (and claset) reference variable replaced by functions
  4177 simpset / simpset_ref;
  4178 
  4179 * no longer supports theory aliases (via merge) and non-trivial
  4180 implicit merge of thms' signatures;
  4181 
  4182 * most internal names of constants changed due to qualified names;
  4183 
  4184 * changed Pure/Sequence interface (see Pure/seq.ML);
  4185 
  4186 
  4187 *** General Changes ***
  4188 
  4189 * hierachically structured name spaces (for consts, types, axms, thms
  4190 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  4191 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  4192 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  4193 long_names for fully qualified output names; NOTE: ML programs
  4194 (special tactics, packages etc.) referring to internal names may have
  4195 to be adapted to cope with fully qualified names; in case of severe
  4196 backward campatibility problems try setting 'global_names' at compile
  4197 time to have enrything declared within a flat name space; one may also
  4198 fine tune name declarations in theories via the 'global' and 'local'
  4199 section;
  4200 
  4201 * reimplemented the implicit simpset and claset using the new anytype
  4202 data filed in signatures; references simpset:simpset ref etc. are
  4203 replaced by functions simpset:unit->simpset and
  4204 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  4205 to patch your ML files accordingly;
  4206 
  4207 * HTML output now includes theory graph data for display with Java
  4208 applet or isatool browser; data generated automatically via isatool
  4209 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  4210 
  4211 * defs may now be conditional; improved rewrite_goals_tac to handle
  4212 conditional equations;
  4213 
  4214 * defs now admits additional type arguments, using TYPE('a) syntax;
  4215 
  4216 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  4217 creates a new theory node; implicit merge of thms' signatures is
  4218 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  4219 transfer:theory->thm->thm in (rare) cases;
  4220 
  4221 * improved handling of draft signatures / theories; draft thms (and
  4222 ctyps, cterms) are automatically promoted to real ones;
  4223 
  4224 * slightly changed interfaces for oracles: admit many per theory, named
  4225 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  4226 
  4227 * print_goals: optional output of const types (set show_consts and
  4228 show_types);
  4229 
  4230 * improved output of warnings (###) and errors (***);
  4231 
  4232 * subgoal_tac displays a warning if the new subgoal has type variables;
  4233 
  4234 * removed old README and Makefiles;
  4235 
  4236 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  4237 
  4238 * removed obsolete init_pps and init_database;
  4239 
  4240 * deleted the obsolete tactical STATE, which was declared by
  4241     fun STATE tacfun st = tacfun st st;
  4242 
  4243 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  4244 (which abbreviates $HOME);
  4245 
  4246 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  4247 use isatool fixseq to adapt your ML programs (this works for fully
  4248 qualified references to the Sequence structure only!);
  4249 
  4250 * use_thy no longer requires writable current directory; it always
  4251 reloads .ML *and* .thy file, if either one is out of date;
  4252 
  4253 
  4254 *** Classical Reasoner ***
  4255 
  4256 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  4257 tactics that use classical reasoning to simplify a subgoal without
  4258 splitting it into several subgoals;
  4259 
  4260 * Safe_tac: like safe_tac but uses the default claset;
  4261 
  4262 
  4263 *** Simplifier ***
  4264 
  4265 * added simplification meta rules:
  4266     (asm_)(full_)simplify: simpset -> thm -> thm;
  4267 
  4268 * simplifier.ML no longer part of Pure -- has to be loaded by object
  4269 logics (again);
  4270 
  4271 * added prems argument to simplification procedures;
  4272 
  4273 * HOL, FOL, ZF: added infix function `addsplits':
  4274   instead of `<simpset> setloop (split_tac <thms>)'
  4275   you can simply write `<simpset> addsplits <thms>'
  4276 
  4277 
  4278 *** Syntax ***
  4279 
  4280 * TYPE('a) syntax for type reflection terms;
  4281 
  4282 * no longer handles consts with name "" -- declare as 'syntax' instead;
  4283 
  4284 * pretty printer: changed order of mixfix annotation preference (again!);
  4285 
  4286 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  4287 
  4288 
  4289 *** HOL ***
  4290 
  4291 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4292   with `addloop' of the simplifier to faciliate case splitting in premises.
  4293 
  4294 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  4295 
  4296 * HOL/Auth: new protocol proofs including some for the Internet
  4297   protocol TLS;
  4298 
  4299 * HOL/Map: new theory of `maps' a la VDM;
  4300 
  4301 * HOL/simplifier: simplification procedures nat_cancel_sums for
  4302 cancelling out common nat summands from =, <, <= (in)equalities, or
  4303 differences; simplification procedures nat_cancel_factor for
  4304 cancelling common factor from =, <, <= (in)equalities over natural
  4305 sums; nat_cancel contains both kinds of procedures, it is installed by
  4306 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  4307 
  4308 * HOL/simplifier: terms of the form
  4309   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  4310   are rewritten to
  4311   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  4312   and those of the form
  4313   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  4314   are rewritten to
  4315   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  4316 
  4317 * HOL/datatype
  4318   Each datatype `t' now comes with a theorem `split_t_case' of the form
  4319 
  4320   P(t_case f1 ... fn x) =
  4321      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  4322         ...
  4323        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  4324      )
  4325 
  4326   and a theorem `split_t_case_asm' of the form
  4327 
  4328   P(t_case f1 ... fn x) =
  4329     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  4330         ...
  4331        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  4332      )
  4333   which can be added to a simpset via `addsplits'. The existing theorems
  4334   expand_list_case and expand_option_case have been renamed to
  4335   split_list_case and split_option_case.
  4336 
  4337 * HOL/Arithmetic:
  4338   - `pred n' is automatically converted to `n-1'.
  4339     Users are strongly encouraged not to use `pred' any longer,
  4340     because it will disappear altogether at some point.
  4341   - Users are strongly encouraged to write "0 < n" rather than
  4342     "n ~= 0". Theorems and proof tools have been modified towards this
  4343     `standard'.
  4344 
  4345 * HOL/Lists:
  4346   the function "set_of_list" has been renamed "set" (and its theorems too);
  4347   the function "nth" now takes its arguments in the reverse order and
  4348   has acquired the infix notation "!" as in "xs!n".
  4349 
  4350 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  4351 
  4352 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  4353   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  4354 
  4355 * HOL/record: extensible records with schematic structural subtyping
  4356 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  4357 still lacks various theorems and concrete record syntax;
  4358 
  4359 
  4360 *** HOLCF ***
  4361 
  4362 * removed "axioms" and "generated by" sections;
  4363 
  4364 * replaced "ops" section by extended "consts" section, which is capable of
  4365   handling the continuous function space "->" directly;
  4366 
  4367 * domain package:
  4368   . proves theorems immediately and stores them in the theory,
  4369   . creates hierachical name space,
  4370   . now uses normal mixfix annotations (instead of cinfix...),
  4371   . minor changes to some names and values (for consistency),
  4372   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  4373   . separator between mutual domain defs: changed "," to "and",
  4374   . improved handling of sort constraints;  now they have to
  4375     appear on the left-hand side of the equations only;
  4376 
  4377 * fixed LAM <x,y,zs>.b syntax;
  4378 
  4379 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  4380 adm (%x. P (t x)), where P is chainfinite and t continuous;
  4381 
  4382 
  4383 *** FOL and ZF ***
  4384 
  4385 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4386   with `addloop' of the simplifier to faciliate case splitting in premises.
  4387 
  4388 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  4389 in HOL, they strip ALL and --> from proved theorems;
  4390 
  4391 
  4392 
  4393 New in Isabelle94-8 (May 1997)
  4394 ------------------------------
  4395 
  4396 *** General Changes ***
  4397 
  4398 * new utilities to build / run / maintain Isabelle etc. (in parts
  4399 still somewhat experimental); old Makefiles etc. still functional;
  4400 
  4401 * new 'Isabelle System Manual';
  4402 
  4403 * INSTALL text, together with ./configure and ./build scripts;
  4404 
  4405 * reimplemented type inference for greater efficiency, better error
  4406 messages and clean internal interface;
  4407 
  4408 * prlim command for dealing with lots of subgoals (an easier way of
  4409 setting goals_limit);
  4410 
  4411 
  4412 *** Syntax ***
  4413 
  4414 * supports alternative (named) syntax tables (parser and pretty
  4415 printer); internal interface is provided by add_modesyntax(_i);
  4416 
  4417 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  4418 be used in conjunction with the Isabelle symbol font; uses the
  4419 "symbols" syntax table;
  4420 
  4421 * added token_translation interface (may translate name tokens in
  4422 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  4423 the current print_mode); IMPORTANT: user print translation functions
  4424 are responsible for marking newly introduced bounds
  4425 (Syntax.mark_boundT);
  4426 
  4427 * token translations for modes "xterm" and "xterm_color" that display
  4428 names in bold, underline etc. or colors (which requires a color
  4429 version of xterm);
  4430 
  4431 * infixes may now be declared with names independent of their syntax;
  4432 
  4433 * added typed_print_translation (like print_translation, but may
  4434 access type of constant);
  4435 
  4436 
  4437 *** Classical Reasoner ***
  4438 
  4439 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  4440 some limitations.  Blast_tac...
  4441   + ignores addss, addbefore, addafter; this restriction is intrinsic
  4442   + ignores elimination rules that don't have the correct format
  4443         (the conclusion MUST be a formula variable)
  4444   + ignores types, which can make HOL proofs fail
  4445   + rules must not require higher-order unification, e.g. apply_type in ZF
  4446     [message "Function Var's argument not a bound variable" relates to this]
  4447   + its proof strategy is more general but can actually be slower
  4448 
  4449 * substitution with equality assumptions no longer permutes other
  4450 assumptions;
  4451 
  4452 * minor changes in semantics of addafter (now called addaltern); renamed
  4453 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  4454 (and access functions for it);
  4455 
  4456 * improved combination of classical reasoner and simplifier:
  4457   + functions for handling clasimpsets
  4458   + improvement of addss: now the simplifier is called _after_ the
  4459     safe steps.
  4460   + safe variant of addss called addSss: uses safe simplifications
  4461     _during_ the safe steps. It is more complete as it allows multiple
  4462     instantiations of unknowns (e.g. with slow_tac).
  4463 
  4464 *** Simplifier ***
  4465 
  4466 * added interface for simplification procedures (functions that
  4467 produce *proven* rewrite rules on the fly, depending on current
  4468 redex);
  4469 
  4470 * ordering on terms as parameter (used for ordered rewriting);
  4471 
  4472 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  4473 
  4474 * the solver is now split into a safe and an unsafe part.
  4475 This should be invisible for the normal user, except that the
  4476 functions setsolver and addsolver have been renamed to setSolver and
  4477 addSolver; added safe_asm_full_simp_tac;
  4478 
  4479 
  4480 *** HOL ***
  4481 
  4482 * a generic induction tactic `induct_tac' which works for all datatypes and
  4483 also for type `nat';
  4484 
  4485 * a generic case distinction tactic `exhaust_tac' which works for all
  4486 datatypes and also for type `nat';
  4487 
  4488 * each datatype comes with a function `size';
  4489 
  4490 * patterns in case expressions allow tuple patterns as arguments to
  4491 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  4492 
  4493 * primrec now also works with type nat;
  4494 
  4495 * recdef: a new declaration form, allows general recursive functions to be
  4496 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  4497 
  4498 * the constant for negation has been renamed from "not" to "Not" to
  4499 harmonize with FOL, ZF, LK, etc.;
  4500 
  4501 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  4502 infinite lists;
  4503 
  4504 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  4505 
  4506 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  4507 problems in commutative rings, using axiomatic type classes for + and *;
  4508 
  4509 * more examples in HOL/MiniML and HOL/Auth;
  4510 
  4511 * more default rewrite rules for quantifiers, union/intersection;
  4512 
  4513 * a new constant `arbitrary == @x.False';
  4514 
  4515 * HOLCF/IOA replaces old HOL/IOA;
  4516 
  4517 * HOLCF changes: derived all rules and arities
  4518   + axiomatic type classes instead of classes
  4519   + typedef instead of faking type definitions
  4520   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  4521   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  4522   + eliminated the types void, one, tr
  4523   + use unit lift and bool lift (with translations) instead of one and tr
  4524   + eliminated blift from Lift3.thy (use Def instead of blift)
  4525   all eliminated rules are derived as theorems --> no visible changes ;
  4526 
  4527 
  4528 *** ZF ***
  4529 
  4530 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  4531 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  4532 as ZF_cs addSIs [equalityI];
  4533 
  4534 
  4535 
  4536 New in Isabelle94-7 (November 96)
  4537 ---------------------------------
  4538 
  4539 * allowing negative levels (as offsets) in prlev and choplev;
  4540 
  4541 * super-linear speedup for large simplifications;
  4542 
  4543 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  4544 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  4545 FAIL); can suppress it using the command Delsimps (ex_simps @
  4546 all_simps); De Morgan laws are also now included, by default;
  4547 
  4548 * improved printing of ==>  :  ~:
  4549 
  4550 * new object-logic "Sequents" adds linear logic, while replacing LK
  4551 and Modal (thanks to Sara Kalvala);
  4552 
  4553 * HOL/Auth: correctness proofs for authentication protocols;
  4554 
  4555 * HOL: new auto_tac combines rewriting and classical reasoning (many
  4556 examples on HOL/Auth);
  4557 
  4558 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  4559 the rewriter and classical reasoner simultaneously;
  4560 
  4561 * function uresult no longer returns theorems in "standard" format;
  4562 regain previous version by: val uresult = standard o uresult;
  4563 
  4564 
  4565 
  4566 New in Isabelle94-6
  4567 -------------------
  4568 
  4569 * oracles -- these establish an interface between Isabelle and trusted
  4570 external reasoners, which may deliver results as theorems;
  4571 
  4572 * proof objects (in particular record all uses of oracles);
  4573 
  4574 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  4575 
  4576 * "constdefs" section in theory files;
  4577 
  4578 * "primrec" section (HOL) no longer requires names;
  4579 
  4580 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  4581 
  4582 
  4583 
  4584 New in Isabelle94-5
  4585 -------------------
  4586 
  4587 * reduced space requirements;
  4588 
  4589 * automatic HTML generation from theories;
  4590 
  4591 * theory files no longer require "..." (quotes) around most types;
  4592 
  4593 * new examples, including two proofs of the Church-Rosser theorem;
  4594 
  4595 * non-curried (1994) version of HOL is no longer distributed;
  4596 
  4597 
  4598 
  4599 New in Isabelle94-4
  4600 -------------------
  4601 
  4602 * greatly reduced space requirements;
  4603 
  4604 * theory files (.thy) no longer require \...\ escapes at line breaks;
  4605 
  4606 * searchable theorem database (see the section "Retrieving theorems" on
  4607 page 8 of the Reference Manual);
  4608 
  4609 * new examples, including Grabczewski's monumental case study of the
  4610 Axiom of Choice;
  4611 
  4612 * The previous version of HOL renamed to Old_HOL;
  4613 
  4614 * The new version of HOL (previously called CHOL) uses a curried syntax
  4615 for functions.  Application looks like f a b instead of f(a,b);
  4616 
  4617 * Mutually recursive inductive definitions finally work in HOL;
  4618 
  4619 * In ZF, pattern-matching on tuples is now available in all abstractions and
  4620 translates to the operator "split";
  4621 
  4622 
  4623 
  4624 New in Isabelle94-3
  4625 -------------------
  4626 
  4627 * new infix operator, addss, allowing the classical reasoner to
  4628 perform simplification at each step of its search.  Example:
  4629         fast_tac (cs addss ss)
  4630 
  4631 * a new logic, CHOL, the same as HOL, but with a curried syntax
  4632 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  4633 look like (a,b) instead of <a,b>;
  4634 
  4635 * PLEASE NOTE: CHOL will eventually replace HOL!
  4636 
  4637 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  4638 It translates to the operator "split".  A new theory of integers is available;
  4639 
  4640 * In ZF, integer numerals now denote two's-complement binary integers.
  4641 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  4642 
  4643 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  4644 of the Axiom of Choice;
  4645 
  4646 
  4647 
  4648 New in Isabelle94-2
  4649 -------------------
  4650 
  4651 * Significantly faster resolution;
  4652 
  4653 * the different sections in a .thy file can now be mixed and repeated
  4654 freely;
  4655 
  4656 * Database of theorems for FOL, HOL and ZF.  New
  4657 commands including qed, qed_goal and bind_thm store theorems in the database.
  4658 
  4659 * Simple database queries: return a named theorem (get_thm) or all theorems of
  4660 a given theory (thms_of), or find out what theory a theorem was proved in
  4661 (theory_of_thm);
  4662 
  4663 * Bugs fixed in the inductive definition and datatype packages;
  4664 
  4665 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  4666 and HOL_dup_cs obsolete;
  4667 
  4668 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  4669 have been removed;
  4670 
  4671 * Simpler definition of function space in ZF;
  4672 
  4673 * new results about cardinal and ordinal arithmetic in ZF;
  4674 
  4675 * 'subtype' facility in HOL for introducing new types as subsets of existing
  4676 types;
  4677 
  4678 
  4679 $Id$