NEWS
author paulson
Wed Jan 03 18:30:57 2007 +0100 (2007-01-03)
changeset 21980 d22f7e3c5ad9
parent 21960 0574f192b78a
child 22125 cc35c948f6c5
permissions -rw-r--r--
x-symbol is no longer switched off in the ATP linkup
     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 See HOL/ex/Code*.thy for examples.
    83 
    84 Theorem attributs for selecting and transforming function equations theorems:
    85 
    86     [code fun]:       select a theorem as function equation for a specific constant
    87     [code nofun]:     deselect a theorem as function equation for a specific constant
    88     [code inline]:    select an equation theorem for unfolding (inlining) in place
    89     [code noinline]:  deselect an equation theorem for unfolding (inlining) in place
    90 
    91 User-defined serializations (target in {SML, Haskell}):
    92 
    93     code_const <and-list of constants (term syntax)>
    94       {(target) <and-list of const target syntax>}+
    95 
    96     code_type <and-list of type constructors>
    97       {(target) <and-list of type target syntax>}+
    98 
    99     code_instance <and-list of instances>
   100       {(target)}+
   101         where instance ::= <type constructor> :: <class>
   102 
   103     code_class <and_list of classes>
   104       {(target) <and-list of class target syntax>}+
   105         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
   106 
   107 For code_instance and code_class, target SML is silently ignored.
   108 
   109 See HOL theories and HOL/ex/Code*.thy for usage examples.  Doc/Isar/Advanced/Codegen/
   110 provides a tutorial.
   111 
   112 * Command 'no_translations' removes translation rules from theory
   113 syntax.
   114 
   115 * Overloaded definitions are now actually checked for acyclic
   116 dependencies.  The overloading scheme is slightly more general than
   117 that of Haskell98, although Isabelle does not demand an exact
   118 correspondence to type class and instance declarations.
   119 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
   120 exotic versions of overloading -- at the discretion of the user!
   121 
   122 Polymorphic constants are represented via type arguments, i.e. the
   123 instantiation that matches an instance against the most general
   124 declaration given in the signature.  For example, with the declaration
   125 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
   126 as c(nat).  Overloading is essentially simultaneous structural
   127 recursion over such type arguments.  Incomplete specification patterns
   128 impose global constraints on all occurrences, e.g. c('a * 'a) on the
   129 LHS means that more general c('a * 'b) will be disallowed on any RHS.
   130 Command 'print_theory' outputs the normalized system of recursive
   131 equations, see section "definitions".
   132 
   133 * Isar: improper proof element 'guess' is like 'obtain', but derives
   134 the obtained context from the course of reasoning!  For example:
   135 
   136   assume "EX x y. A x & B y"   -- "any previous fact"
   137   then guess x and y by clarify
   138 
   139 This technique is potentially adventurous, depending on the facts and
   140 proof tools being involved here.
   141 
   142 * Isar: known facts from the proof context may be specified as literal
   143 propositions, using ASCII back-quote syntax.  This works wherever
   144 named facts used to be allowed so far, in proof commands, proof
   145 methods, attributes etc.  Literal facts are retrieved from the context
   146 according to unification of type and term parameters.  For example,
   147 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
   148 theorems in the current context, then these are valid literal facts:
   149 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
   150 
   151 There is also a proof method "fact" which does the same composition
   152 for explicit goal states, e.g. the following proof texts coincide with
   153 certain special cases of literal facts:
   154 
   155   have "A" by fact                 ==  note `A`
   156   have "A ==> B" by fact           ==  note `A ==> B`
   157   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
   158   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
   159 
   160 * Isar: ":" (colon) is no longer a symbolic identifier character in
   161 outer syntax.  Thus symbolic identifiers may be used without
   162 additional white space in declarations like this: ``assume *: A''.
   163 
   164 * Isar: 'print_facts' prints all local facts of the current context,
   165 both named and unnamed ones.
   166 
   167 * Isar: 'def' now admits simultaneous definitions, e.g.:
   168 
   169   def x == "t" and y == "u"
   170 
   171 * Isar: added command 'unfolding', which is structurally similar to
   172 'using', but affects both the goal state and facts by unfolding given
   173 rewrite rules.  Thus many occurrences of the 'unfold' method or
   174 'unfolded' attribute may be replaced by first-class proof text.
   175 
   176 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
   177 and command 'unfolding' now all support object-level equalities
   178 (potentially conditional).  The underlying notion of rewrite rule is
   179 analogous to the 'rule_format' attribute, but *not* that of the
   180 Simplifier (which is usually more generous).
   181 
   182 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
   183 method expression within a sandbox consisting of the first N
   184 sub-goals, which need to exist.  For example, ``simp_all [3]''
   185 simplifies the first three sub-goals, while (rule foo, simp_all)[]
   186 simplifies all new goals that emerge from applying rule foo to the
   187 originally first one.
   188 
   189 * Isar: schematic goals are no longer restricted to higher-order
   190 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
   191 expected.
   192 
   193 * Isar: the conclusion of a long theorem statement is now either
   194 'shows' (a simultaneous conjunction, as before), or 'obtains'
   195 (essentially a disjunction of cases with local parameters and
   196 assumptions).  The latter allows to express general elimination rules
   197 adequately; in this notation common elimination rules look like this:
   198 
   199   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
   200     assumes "EX x. P x"
   201     obtains x where "P x"
   202 
   203   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
   204     assumes "A & B"
   205     obtains A and B
   206 
   207   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
   208     assumes "A | B"
   209     obtains
   210       A
   211     | B
   212 
   213 The subsequent classical rules even refer to the formal "thesis"
   214 explicitly:
   215 
   216   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
   217     obtains "~ thesis"
   218 
   219   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
   220     obtains "thesis ==> something"
   221 
   222 The actual proof of an 'obtains' statement is analogous to that of the
   223 Isar proof element 'obtain', only that there may be several cases.
   224 Optional case names may be specified in parentheses; these will be
   225 available both in the present proof and as annotations in the
   226 resulting rule, for later use with the 'cases' method (cf. attribute
   227 case_names).
   228 
   229 * Isar: the assumptions of a long theorem statement are available as
   230 "assms" fact in the proof context.  This is more appropriate than the
   231 (historical) "prems", which refers to all assumptions of the current
   232 context, including those from the target locale, proof body etc.
   233 
   234 * Isar: 'print_statement' prints theorems from the current theory or
   235 proof context in long statement form, according to the syntax of a
   236 top-level lemma.
   237 
   238 * Isar: 'obtain' takes an optional case name for the local context
   239 introduction rule (default "that").
   240 
   241 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
   242 explicit (is "_ ==> ?foo") in the rare cases where this still happens
   243 to occur.
   244 
   245 * Pure: syntax "CONST name" produces a fully internalized constant
   246 according to the current context.  This is particularly useful for
   247 syntax translations that should refer to internal constant
   248 representations independently of name spaces.
   249 
   250 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
   251 instead of "FOO ". This allows multiple binder declarations to coexist
   252 in the same context.  INCOMPATIBILITY.
   253 
   254 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
   255 primitive that also works in a locale context (both for constants and
   256 fixed variables).  Type declaration and internal syntactic
   257 representation of given constants retrieved from the context.
   258 
   259 * Isar/locales: new derived specification elements 'axiomatization',
   260 'definition', 'abbreviation', which support type-inference, admit
   261 object-level specifications (equality, equivalence).  See also the
   262 isar-ref manual.  Examples:
   263 
   264   axiomatization
   265     eq  (infix "===" 50) where
   266     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
   267 
   268   definition "f x y = x + y + 1"
   269   definition g where "g x = f x x"
   270 
   271   abbreviation
   272     neq  (infix "=!=" 50) where
   273     "x =!= y == ~ (x === y)"
   274 
   275 These specifications may be also used in a locale context.  Then the
   276 constants being introduced depend on certain fixed parameters, and the
   277 constant name is qualified by the locale base name.  An internal
   278 abbreviation takes care for convenient input and output, making the
   279 parameters implicit and using the original short name.  See also
   280 HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
   281 entities from a monomorphic theory.
   282 
   283 Presently, abbreviations are only available 'in' a target locale, but
   284 not inherited by general import expressions.  Also note that
   285 'abbreviation' may be used as a type-safe replacement for 'syntax' +
   286 'translations' in common applications.
   287 
   288 Concrete syntax is attached to specified constants in internal form,
   289 independently of name spaces.  The parse tree representation is
   290 slightly different -- use 'notation' instead of raw 'syntax', and
   291 'translations' with explicit "CONST" markup to accommodate this.
   292 
   293 * Pure: command 'print_abbrevs' prints all constant abbreviations of
   294 the current context.  Print mode "no_abbrevs" prevents inversion of
   295 abbreviations on output.
   296 
   297 * Isar/locales: improved parameter handling:
   298 - use of locales "var" and "struct" no longer necessary;
   299 - parameter renamings are no longer required to be injective.
   300   This enables, for example, to define a locale for endomorphisms thus:
   301   locale endom = homom mult mult h.
   302 
   303 * Isar/locales: changed the way locales with predicates are defined.
   304 Instead of accumulating the specification, the imported expression is
   305 now an interpretation.
   306 INCOMPATIBILITY: different normal form of locale expressions.
   307 In particular, in interpretations of locales with predicates,
   308 goals repesenting already interpreted fragments are not removed
   309 automatically.  Use methods `intro_locales' and `unfold_locales'; see below.
   310 
   311 * Isar/locales: new methods `intro_locales' and `unfold_locales' provide
   312 backward reasoning on locales predicates.  The methods are aware of
   313 interpretations and discharge corresponding goals.  `intro_locales' is
   314 less aggressive then `unfold_locales' and does not unfold predicates to
   315 assumptions.
   316 
   317 * Isar/locales: the order in which locale fragments are accumulated
   318 has changed.  This enables to override declarations from fragments
   319 due to interpretations -- for example, unwanted simp rules.
   320 
   321 * Provers/induct: improved internal context management to support
   322 local fixes and defines on-the-fly.  Thus explicit meta-level
   323 connectives !! and ==> are rarely required anymore in inductive goals
   324 (using object-logic connectives for this purpose has been long
   325 obsolete anyway).  The subsequent proof patterns illustrate advanced
   326 techniques of natural induction; general datatypes and inductive sets
   327 work analogously (see also src/HOL/Lambda for realistic examples).
   328 
   329 (1) This is how to ``strengthen'' an inductive goal wrt. certain
   330 parameters:
   331 
   332   lemma
   333     fixes n :: nat and x :: 'a
   334     assumes a: "A n x"
   335     shows "P n x"
   336     using a                     -- {* make induct insert fact a *}
   337   proof (induct n arbitrary: x) -- {* generalize goal to "!!x. A n x ==> P n x" *}
   338     case 0
   339     show ?case sorry
   340   next
   341     case (Suc n)
   342     note `!!x. A n x ==> P n x` -- {* induction hypothesis, according to induction rule *}
   343     note `A (Suc n) x`          -- {* induction premise, stemming from fact a *}
   344     show ?case sorry
   345   qed
   346 
   347 (2) This is how to perform induction over ``expressions of a certain
   348 form'', using a locally defined inductive parameter n == "a x"
   349 together with strengthening (the latter is usually required to get
   350 sufficiently flexible induction hypotheses):
   351 
   352   lemma
   353     fixes a :: "'a => nat"
   354     assumes a: "A (a x)"
   355     shows "P (a x)"
   356     using a
   357   proof (induct n == "a x" arbitrary: x)
   358     ...
   359 
   360 See also HOL/Isar_examples/Puzzle.thy for an application of the this
   361 particular technique.
   362 
   363 (3) This is how to perform existential reasoning ('obtains' or
   364 'obtain') by induction, while avoiding explicit object-logic
   365 encodings:
   366 
   367   lemma
   368     fixes n :: nat
   369     obtains x :: 'a where "P n x" and "Q n x"
   370   proof (induct n arbitrary: thesis)
   371     case 0
   372     obtain x where "P 0 x" and "Q 0 x" sorry
   373     then show thesis by (rule 0)
   374   next
   375     case (Suc n)
   376     obtain x where "P n x" and "Q n x" by (rule Suc.hyps)
   377     obtain x where "P (Suc n) x" and "Q (Suc n) x" sorry
   378     then show thesis by (rule Suc.prems)
   379   qed
   380 
   381 Here the 'arbitrary: thesis' specification essentially modifies the
   382 scope of the formal thesis parameter, in order to the get the whole
   383 existence statement through the induction as expected.
   384 
   385 * Provers/induct: mutual induction rules are now specified as a list
   386 of rule sharing the same induction cases.  HOL packages usually
   387 provide foo_bar.inducts for mutually defined items foo and bar
   388 (e.g. inductive sets or datatypes).  INCOMPATIBILITY, users need to
   389 specify mutual induction rules differently, i.e. like this:
   390 
   391   (induct rule: foo_bar.inducts)
   392   (induct set: foo bar)
   393   (induct type: foo bar)
   394 
   395 The ML function ProjectRule.projections turns old-style rules into the
   396 new format.
   397 
   398 * Provers/induct: improved handling of simultaneous goals.  Instead of
   399 introducing object-level conjunction, the statement is now split into
   400 several conclusions, while the corresponding symbolic cases are
   401 nested accordingly.  INCOMPATIBILITY, proofs need to be structured
   402 explicitly.  For example:
   403 
   404   lemma
   405     fixes n :: nat
   406     shows "P n" and "Q n"
   407   proof (induct n)
   408     case 0 case 1
   409     show "P 0" sorry
   410   next
   411     case 0 case 2
   412     show "Q 0" sorry
   413   next
   414     case (Suc n) case 1
   415     note `P n` and `Q n`
   416     show "P (Suc n)" sorry
   417   next
   418     case (Suc n) case 2
   419     note `P n` and `Q n`
   420     show "Q (Suc n)" sorry
   421   qed
   422 
   423 The split into subcases may be deferred as follows -- this is
   424 particularly relevant for goal statements with local premises.
   425 
   426   lemma
   427     fixes n :: nat
   428     shows "A n ==> P n" and "B n ==> Q n"
   429   proof (induct n)
   430     case 0
   431     {
   432       case 1
   433       note `A 0`
   434       show "P 0" sorry
   435     next
   436       case 2
   437       note `B 0`
   438       show "Q 0" sorry
   439     }
   440   next
   441     case (Suc n)
   442     note `A n ==> P n` and `B n ==> Q n`
   443     {
   444       case 1
   445       note `A (Suc n)`
   446       show "P (Suc n)" sorry
   447     next
   448       case 2
   449       note `B (Suc n)`
   450       show "Q (Suc n)" sorry
   451     }
   452   qed
   453 
   454 If simultaneous goals are to be used with mutual rules, the statement
   455 needs to be structured carefully as a two-level conjunction, using
   456 lists of propositions separated by 'and':
   457 
   458   lemma
   459     shows "a : A ==> P1 a"
   460           "a : A ==> P2 a"
   461       and "b : B ==> Q1 b"
   462           "b : B ==> Q2 b"
   463           "b : B ==> Q3 b"
   464   proof (induct set: A B)
   465 
   466 * Provers/induct: support coinduction as well.  See
   467 src/HOL/Library/Coinductive_List.thy for various examples.
   468 
   469 * Attribute "symmetric" produces result with standardized schematic
   470 variables (index 0).  Potential INCOMPATIBILITY.
   471 
   472 * Simplifier: by default the simplifier trace only shows top level rewrites
   473 now. That is, trace_simp_depth_limit is set to 1 by default. Thus there is
   474 less danger of being flooded by the trace. The trace indicates where parts
   475 have been suppressed.
   476   
   477 * Provers/classical: removed obsolete classical version of elim_format
   478 attribute; classical elim/dest rules are now treated uniformly when
   479 manipulating the claset.
   480 
   481 * Provers/classical: stricter checks to ensure that supplied intro,
   482 dest and elim rules are well-formed; dest and elim rules must have at
   483 least one premise.
   484 
   485 * Provers/classical: attributes dest/elim/intro take an optional
   486 weight argument for the rule (just as the Pure versions).  Weights are
   487 ignored by automated tools, but determine the search order of single
   488 rule steps.
   489 
   490 * Syntax: input syntax now supports dummy variable binding "%_. b",
   491 where the body does not mention the bound variable.  Note that dummy
   492 patterns implicitly depend on their context of bounds, which makes
   493 "{_. _}" match any set comprehension as expected.  Potential
   494 INCOMPATIBILITY -- parse translations need to cope with syntactic
   495 constant "_idtdummy" in the binding position.
   496 
   497 * Syntax: removed obsolete syntactic constant "_K" and its associated
   498 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
   499 for example "A -> B" => "Pi A (%_. B)".
   500 
   501 * Pure: 'class_deps' command visualizes the subclass relation, using
   502 the graph browser tool.
   503 
   504 * Pure: 'print_theory' now suppresses entities with internal name
   505 (trailing "_") by default; use '!' option for full details.
   506 
   507 
   508 *** HOL ***
   509 
   510 * New syntactic class "size"; overloaded constant "size" now
   511 has type "'a::size ==> bool"
   512 
   513 * Constants "Divides.op div", "Divides.op mod" and "Divides.op dvd" no named
   514   "Divides.div", "Divides.mod" and "Divides.dvd"
   515   INCOMPATIBILITY for ML code directly refering to constant names.
   516 
   517 * Replaced "auto_term" by the conceptually simpler method "relation",
   518 which just applies the instantiated termination rule with no further
   519 simplifications.
   520 INCOMPATIBILITY: 
   521 Replace 
   522         termination by (auto_term "MYREL")
   523 with 
   524         termination by (relation "MYREL") auto
   525 
   526 * Automated termination proofs "by lexicographic_order" are now
   527 included in the abbreviated function command "fun". No explicit
   528 "termination" command is necessary anymore.
   529 INCOMPATIBILITY: If a "fun"-definition cannot be proved terminating by
   530 a lexicographic size order, then the command fails. Use the expanded
   531 version "function" for these cases.
   532 
   533 * New method "lexicographic_order" automatically synthesizes
   534 termination relations as lexicographic combinations of size measures. 
   535 Usage for (function package) termination proofs:
   536 
   537 termination 
   538 by lexicographic_order
   539 
   540 * Records: generalised field-update to take a function on the field 
   541 rather than the new value: r(|A := x|) is translated to A_update (K x) r
   542 The K-combinator that is internally used is called K_record.
   543 INCOMPATIBILITY: Usage of the plain update functions has to be
   544 adapted.
   545  
   546 * axclass "semiring_0" now contains annihilation axioms 
   547 ("x * 0 = 0","0 * x = 0"), which are required for a semiring. Richer 
   548 structures do not inherit from semiring_0 anymore, because this property 
   549 is a theorem there, not an axiom.
   550 INCOMPATIBILITY: In instances of semiring_0, there is more to prove, but 
   551 this is mostly trivial.
   552 
   553 * axclass "recpower" was generalized to arbitrary monoids, not just 
   554 commutative semirings.
   555 INCOMPATIBILITY: If you use recpower and need commutativity or a semiring
   556 property, add the corresponding classes.
   557 
   558 * Locale Lattic_Locales.partial_order changed (to achieve consistency with
   559 axclass order):
   560 - moved to Orderings.partial_order
   561 - additional parameter ``less''
   562 INCOMPATIBILITY.
   563 
   564 * Constant "List.list_all2" in List.thy now uses authentic syntax.
   565 INCOMPATIBILITY: translations containing list_all2 may go wrong. On Isar
   566 level, use abbreviations instead.
   567 
   568 * Constant "List.op mem" in List.thy now has proper name: "List.memberl"
   569 INCOMPATIBILITY: rarely occuring name references (e.g. ``List.op mem.simps'')
   570 require renaming (e.g. ``List.memberl.simps'').
   571 
   572 * Renamed constants in HOL.thy:
   573     0      ~> HOL.zero
   574     1      ~> HOL.one
   575 INCOMPATIBILITY: ML code directly refering to constant names may need adaption
   576 This in general only affects hand-written proof tactics, simprocs and so on.
   577 
   578 * New theory Code_Generator providing class 'eq',
   579 allowing for code generation with polymorphic equality.
   580 
   581 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has been
   582 abandoned in favour of plain 'int'. INCOMPATIBILITY -- Significant changes
   583 for setting up numeral syntax for types:
   584 
   585   - new constants Numeral.pred and Numeral.succ instead
   586       of former Numeral.bin_pred and Numeral.bin_succ.
   587   - Use integer operations instead of bin_add, bin_mult and so on.
   588   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
   589   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
   590 
   591 See HOL/Integ/IntArith.thy for an example setup.
   592 
   593 * New top level command 'normal_form' computes the normal form of a term
   594 that may contain free variables. For example 'normal_form "rev[a,b,c]"'
   595 prints '[b,c,a]'. This command is suitable for heavy-duty computations
   596 because the functions are compiled to ML first.
   597 INCOMPATIBILITY: new keywords 'normal_form' must quoted when used as
   598 an identifier.
   599 
   600 * Alternative iff syntax "A <-> B" for equality on bool (with priority
   601 25 like -->); output depends on the "iff" print_mode, the default is
   602 "A = B" (with priority 50).
   603 
   604 * Renamed constants in HOL.thy and Orderings.thy:
   605     op +   ~> HOL.plus
   606     op -   ~> HOL.minus
   607     uminus ~> HOL.uminus
   608     op *   ~> HOL.times
   609     op <   ~> Orderings.less
   610     op <=  ~> Orderings.less_eq
   611 
   612 Adaptions may be required in the following cases:
   613 
   614 a) User-defined constants using any of the names "plus", "minus", "times",
   615 "less" or "less_eq". The standard syntax translations for "+", "-" and "*"
   616 may go wrong.
   617 INCOMPATIBILITY: use more specific names.
   618 
   619 b) Variables named "plus", "minus", "times", "less", "less_eq"
   620 INCOMPATIBILITY: use more specific names.
   621 
   622 c) Permutative equations (e.g. "a + b = b + a")
   623 Since the change of names also changes the order of terms, permutative
   624 rewrite rules may get applied in a different order. Experience shows that
   625 this is rarely the case (only two adaptions in the whole Isabelle
   626 distribution).
   627 INCOMPATIBILITY: rewrite proofs
   628 
   629 d) ML code directly refering to constant names
   630 This in general only affects hand-written proof tactics, simprocs and so on.
   631 INCOMPATIBILITY: grep your sourcecode and replace names.
   632 
   633 * Relations less (<) and less_eq (<=) are also available on type bool.
   634 Modified syntax to disallow nesting without explicit parentheses,
   635 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".
   636 
   637 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
   638 
   639 * Relation composition operator "op O" now has precedence 75 and binds
   640 stronger than union and intersection. INCOMPATIBILITY.
   641 
   642 * The old set interval syntax "{m..n(}" (and relatives) has been removed.
   643   Use "{m..<n}" (and relatives) instead.
   644 
   645 * In the context of the assumption "~(s = t)" the Simplifier rewrites
   646 "t = s" to False (by simproc "neq_simproc").  For backward
   647 compatibility this can be disabled by ML "reset use_neq_simproc".
   648 
   649 * "m dvd n" where m and n are numbers is evaluated to True/False by simp.
   650 
   651 * Theorem Cons_eq_map_conv no longer has attribute `simp'.
   652 
   653 * Theorem setsum_mult renamed to setsum_right_distrib.
   654 
   655 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
   656 'rule' method.
   657 
   658 * Tactics 'sat' and 'satx' reimplemented, several improvements: goals
   659 no longer need to be stated as "<prems> ==> False", equivalences (i.e.
   660 "=" on type bool) are handled, variable names of the form "lit_<n>"
   661 are no longer reserved, significant speedup.
   662 
   663 * Tactics 'sat' and 'satx' can now replay MiniSat proof traces.  zChaff is
   664 still supported as well.
   665 
   666 * inductive and datatype: provide projections of mutual rules, bundled
   667 as foo_bar.inducts;
   668 
   669 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to Library.
   670 
   671 * Library: moved theory Accessible_Part to main HOL.
   672 
   673 * Library: added theory Coinductive_List of potentially infinite lists
   674 as greatest fixed-point.
   675 
   676 * Library: added theory AssocList which implements (finite) maps as
   677 association lists.
   678 
   679 * New proof method "evaluation" for efficiently solving a goal (i.e. a
   680 boolean expression) by compiling it to ML. The goal is "proved" (via
   681 the oracle "Evaluation") if it evaluates to True.
   682 
   683 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
   684 also when invoked by the simplifier.  This results in the simplifier
   685 being more powerful on arithmetic goals.  INCOMPATIBILITY.  Set
   686 fast_arith_split_limit to 0 to obtain the old behavior.
   687 
   688 * Support for hex (0x20) and binary (0b1001) numerals. 
   689 
   690 * New method: reify eqs (t), where eqs are equations for an
   691 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
   692 parameter, computes a term s::'b and a list xs::'a list and proves the
   693 theorem I xs s = t. This is also known as reification or quoting. The
   694 resulting theorem is applied to the subgoal to substitute t with I xs
   695 s.  If t is omitted, the subgoal itself is reified.
   696 
   697 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
   698 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
   699 where f is supposed to be a computable function (in the sense of code
   700 generattion). The method uses reify to compute s and xs as above then
   701 applies corr_thm and uses normalization by evaluation to "prove" f s =
   702 r and finally gets the theorem t = r, which is again applied to the
   703 subgoal. An Example is available in HOL/ex/ReflectionEx.thy.
   704 
   705 * Reflection: Automatic refification now handels binding, an example
   706 is available in HOL/ex/ReflectionEx.thy
   707 
   708 
   709 *** HOL-Algebra ***
   710 
   711 * Formalisation of ideals and the quotient construction over rings.
   712 
   713 * Order and lattice theory no longer based on records.
   714 INCOMPATIBILITY.
   715 
   716 * Renamed lemmas least_carrier -> least_closed and
   717 greatest_carrier -> greatest_closed.  INCOMPATIBILITY.
   718 
   719 * Method algebra is now set up via an attribute.  For examples see
   720 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
   721 of algebraic structures.
   722 
   723 * Renamed `CRing.thy' to `Ring.thy'.  INCOMPATIBILITY.
   724 
   725 
   726 *** HOL-Complex ***
   727 
   728 * Theory Real: new method ferrack implements quantifier elimination
   729 for linear arithmetic over the reals. The quantifier elimination
   730 feature is used only for decision, for compatibility with arith. This
   731 means a goal is either solved or left unchanged, no simplification.
   732 
   733 * Real: New axiomatic classes formalize real normed vector spaces and
   734 algebras, using new overloaded constants scaleR :: real => 'a => 'a
   735 and norm :: 'a => real.
   736 
   737 * Real: New constant of_real :: real => 'a::real_algebra_1 injects from
   738 reals into other types. The overloaded constant Reals :: 'a set is now
   739 defined as range of_real; potential INCOMPATIBILITY.
   740 
   741 * Hyperreal: Several constants that previously worked only for the reals
   742 have been generalized, so they now work over arbitrary vector spaces. Type
   743 annotations may need to be added in some cases; potential INCOMPATIBILITY.
   744 
   745   Infinitesimal  :: ('a::real_normed_vector) star set"
   746   HFinite        :: ('a::real_normed_vector) star set"
   747   HInfinite      :: ('a::real_normed_vector) star set"
   748   approx         :: ('a::real_normed_vector) star => 'a star => bool
   749   monad          :: ('a::real_normed_vector) star => 'a star set
   750   galaxy         :: ('a::real_normed_vector) star => 'a star set
   751   (NS)LIMSEQ     :: [nat, 'a::real_normed_vector, 'a] => bool
   752   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
   753   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
   754   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
   755   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
   756   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
   757   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
   758 
   759 * Complex: Some complex-specific constants are now abbreviations for
   760 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod = hnorm.
   761 Other constants have been entirely removed in favor of the polymorphic
   762 versions (INCOMPATIBILITY):
   763 
   764   approx        <-- capprox
   765   HFinite       <-- CFinite
   766   HInfinite     <-- CInfinite
   767   Infinitesimal <-- CInfinitesimal
   768   monad         <-- cmonad
   769   galaxy        <-- cgalaxy
   770   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
   771   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
   772   (ns)deriv     <-- (ns)cderiv
   773 
   774 
   775 *** ML ***
   776 
   777 * Pure/Isar/args.ML & Pure/Isar/method.ML
   778 
   779 switched argument order in *.syntax lifters.
   780 
   781 * Pure/table:
   782 
   783 Function `...tab.foldl` removed.
   784 INCOMPATIBILITY: use `...tabfold` instead
   785 
   786 * Pure/library:
   787 
   788 `gen_rem(s)` abandoned in favour of `remove` / `subtract`.
   789 INCOMPATIBILITY:
   790 rewrite "gen_rem eq (xs, x)" to "remove (eq o swap) x xs"
   791 rewrite "gen_rems eq (xs, ys)" to "subtract (eq o swap) ys xs"
   792 drop "swap" if "eq" is symmetric.
   793 
   794 * Pure/library:
   795 
   796 infixes `ins` `ins_string` `ins_int` have been abandoned in favour of `insert`.
   797 INCOMPATIBILITY: rewrite "x ins(_...) xs" to "insert (op =) x xs"
   798 
   799 * Pure/General/susp.ML:
   800 
   801 New module for delayed evaluations.
   802 
   803 * Pure/library:
   804 
   805 Semantically identical functions "equal_list" and "eq_list" have been
   806 unified to "eq_list".
   807 
   808 * Pure/library:
   809 
   810   val burrow: ('a list -> 'b list) -> 'a list list -> 'b list list
   811   val fold_burrow: ('a list -> 'c -> 'b list * 'd) -> 'a list list -> 'c -> 'b list list * 'd
   812 
   813 The semantics of "burrow" is: "take a function with *simulatanously*
   814 transforms a list of value, and apply it *simulatanously* to a list of
   815 list of values of the appropriate type". Confer this with "map" which
   816 would *not* apply its argument function simulatanously but in
   817 sequence. "fold_burrow" has an additional context.
   818 
   819 Both actually avoid the usage of "unflat" since they hide away
   820 "unflat" from the user.
   821 
   822 * Pure/library: functions map2 and fold2 with curried syntax for
   823 simultanous mapping and folding:
   824 
   825     val map2: ('a -> 'b -> 'c) -> 'a list -> 'b list -> 'c list
   826     val fold2: ('a -> 'b -> 'c -> 'c) -> 'a list -> 'b list -> 'c -> 'c
   827 
   828 * Pure/library: indexed lists - some functions in the Isabelle library
   829 treating lists over 'a as finite mappings from [0...n] to 'a have been
   830 given more convenient names and signatures reminiscent of similar
   831 functions for alists, tables, etc:
   832 
   833   val nth: 'a list -> int -> 'a 
   834   val nth_map: int -> ('a -> 'a) -> 'a list -> 'a list
   835   val fold_index: (int * 'a -> 'b -> 'b) -> 'a list -> 'b -> 'b
   836 
   837 Note that fold_index starts counting at index 0, not 1 like foldln
   838 used to.
   839 
   840 * Pure/library: general ``divide_and_conquer'' combinator on lists.
   841 
   842 * Pure/General/name_mangler.ML provides a functor for generic name
   843 mangling (bijective mapping from expression values to strings).
   844 
   845 * Pure/General/rat.ML implements rational numbers.
   846 
   847 * Pure/General/table.ML: the join operations now works via exceptions
   848 DUP/SAME instead of type option.  This is simpler in simple cases, and
   849 admits slightly more efficient complex applications.
   850 
   851 * Pure: datatype Context.generic joins theory/Proof.context and
   852 provides some facilities for code that works in either kind of
   853 context, notably GenericDataFun for uniform theory and proof data.
   854 
   855 * Pure: 'advanced' translation functions (parse_translation etc.) now
   856 use Context.generic instead of just theory.
   857 
   858 * Pure: simplified internal attribute type, which is now always
   859 Context.generic * thm -> Context.generic * thm.  Global (theory)
   860 vs. local (Proof.context) attributes have been discontinued, while
   861 minimizing code duplication.  Thm.rule_attribute and
   862 Thm.declaration_attribute build canonical attributes; see also
   863 structure Context for further operations on Context.generic, notably
   864 GenericDataFun.  INCOMPATIBILITY, need to adapt attribute type
   865 declarations and definitions.
   866 
   867 * Pure/kernel: consts certification ignores sort constraints given in
   868 signature declarations.  (This information is not relevant to the
   869 logic, but only for type inference.)  IMPORTANT INTERNAL CHANGE.
   870 
   871 * Pure: axiomatic type classes are now purely definitional, with
   872 explicit proofs of class axioms and super class relations performed
   873 internally.  See Pure/axclass.ML for the main internal interfaces --
   874 notably AxClass.define_class supercedes AxClass.add_axclass, and
   875 AxClass.axiomatize_class/classrel/arity supercede
   876 Sign.add_classes/classrel/arities.
   877 
   878 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
   879 global/local versions on theory vs. Proof.context have been
   880 discontinued; Attrib.syntax and Method.syntax have been adapted
   881 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
   882 attributes, methods, etc.
   883 
   884 * Pure: several functions of signature "... -> theory -> theory * ..."
   885 have been reoriented to "... -> theory -> ... * theory" in order to
   886 allow natural usage in combination with the ||>, ||>>, |-> and
   887 fold_map combinators.
   888 
   889 * Pure: official theorem names (closed derivations) and additional
   890 comments (tags) are now strictly separate.  Name hints -- which are
   891 maintained as tags -- may be attached any time without affecting the
   892 derivation.
   893 
   894 * Pure: primitive rule lift_rule now takes goal cterm instead of an
   895 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
   896 achieve the old behaviour.
   897 
   898 * Pure: the "Goal" constant is now called "prop", supporting a
   899 slightly more general idea of ``protecting'' meta-level rule
   900 statements.
   901 
   902 * Pure: Logic.(un)varify only works in a global context, which is now
   903 enforced instead of silently assumed.  INCOMPATIBILITY, may use
   904 Logic.legacy_(un)varify as temporary workaround.
   905 
   906 * Pure: structure Name provides scalable operations for generating
   907 internal variable names, notably Name.variants etc.  This replaces
   908 some popular functions from term.ML:
   909 
   910   Term.variant		->  Name.variant
   911   Term.variantlist	->  Name.variant_list  (*canonical argument order*)
   912   Term.invent_names	->  Name.invent_list
   913 
   914 Note that low-level renaming rarely occurs in new code -- operations
   915 from structure Variable are used instead (see below).
   916 
   917 * Pure: structure Variable provides fundamental operations for proper
   918 treatment of fixed/schematic variables in a context.  For example,
   919 Variable.import introduces fixes for schematics of given facts and
   920 Variable.export reverses the effect (up to renaming) -- this replaces
   921 various freeze_thaw operations.
   922 
   923 * Pure: structure Goal provides simple interfaces for
   924 init/conclude/finish and tactical prove operations (replacing former
   925 Tactic.prove).  Goal.prove is the canonical way to prove results
   926 within a given context; Goal.prove_global is a degraded version for
   927 theory level goals, including a global Drule.standard.  Note that
   928 OldGoals.prove_goalw_cterm has long been obsolete, since it is
   929 ill-behaved in a local proof context (e.g. with local fixes/assumes or
   930 in a locale context).
   931 
   932 * Isar: simplified treatment of user-level errors, using exception
   933 ERROR of string uniformly.  Function error now merely raises ERROR,
   934 without any side effect on output channels.  The Isar toplevel takes
   935 care of proper display of ERROR exceptions.  ML code may use plain
   936 handle/can/try; cat_error may be used to concatenate errors like this:
   937 
   938   ... handle ERROR msg => cat_error msg "..."
   939 
   940 Toplevel ML code (run directly or through the Isar toplevel) may be
   941 embedded into the Isar toplevel with exception display/debug like
   942 this:
   943 
   944   Isar.toplevel (fn () => ...)
   945 
   946 INCOMPATIBILITY, removed special transform_error facilities, removed
   947 obsolete variants of user-level exceptions (ERROR_MESSAGE,
   948 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
   949 -- use plain ERROR instead.
   950 
   951 * Isar: theory setup now has type (theory -> theory), instead of a
   952 list.  INCOMPATIBILITY, may use #> to compose setup functions.
   953 
   954 * Isar: installed ML toplevel pretty printer for type Proof.context,
   955 subject to ProofContext.debug/verbose flags.
   956 
   957 * Isar: Toplevel.theory_to_proof admits transactions that modify the
   958 theory before entering a proof state.  Transactions now always see a
   959 quasi-functional intermediate checkpoint, both in interactive and
   960 batch mode.
   961 
   962 * Simplifier: the simpset of a running simplification process now
   963 contains a proof context (cf. Simplifier.the_context), which is the
   964 very context that the initial simpset has been retrieved from (by
   965 simpset_of/local_simpset_of).  Consequently, all plug-in components
   966 (solver, looper etc.) may depend on arbitrary proof data.
   967 
   968 * Simplifier.inherit_context inherits the proof context (plus the
   969 local bounds) of the current simplification process; any simproc
   970 etc. that calls the Simplifier recursively should do this!  Removed
   971 former Simplifier.inherit_bounds, which is already included here --
   972 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
   973 specify an explicit context using Simplifier.context/theory_context.
   974 
   975 * Simplifier/Classical Reasoner: more abstract interfaces
   976 change_simpset/claset for modifying the simpset/claset reference of a
   977 theory; raw versions simpset/claset_ref etc. have been discontinued --
   978 INCOMPATIBILITY.
   979 
   980 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
   981 "Trueprop" etc.
   982 
   983 
   984 *** System ***
   985 
   986 * settings: ML_IDENTIFIER -- which is appended to user specific heap
   987 locations -- now includes the Isabelle version identifier as well.
   988 This simplifies use of multiple Isabelle installations.
   989 
   990 * isabelle-process: option -S (secure mode) disables some critical
   991 operations, notably runtime compilation and evaluation of ML source
   992 code.
   993 
   994 
   995 New in Isabelle2005 (October 2005)
   996 ----------------------------------
   997 
   998 *** General ***
   999 
  1000 * Theory headers: the new header syntax for Isar theories is
  1001 
  1002   theory <name>
  1003   imports <theory1> ... <theoryN>
  1004   uses <file1> ... <fileM>
  1005   begin
  1006 
  1007 where the 'uses' part is optional.  The previous syntax
  1008 
  1009   theory <name> = <theory1> + ... + <theoryN>:
  1010 
  1011 will disappear in the next release.  Use isatool fixheaders to convert
  1012 existing theory files.  Note that there is no change in ancient
  1013 non-Isar theories now, but these will disappear soon.
  1014 
  1015 * Theory loader: parent theories can now also be referred to via
  1016 relative and absolute paths.
  1017 
  1018 * Command 'find_theorems' searches for a list of criteria instead of a
  1019 list of constants. Known criteria are: intro, elim, dest, name:string,
  1020 simp:term, and any term. Criteria can be preceded by '-' to select
  1021 theorems that do not match. Intro, elim, dest select theorems that
  1022 match the current goal, name:s selects theorems whose fully qualified
  1023 name contain s, and simp:term selects all simplification rules whose
  1024 lhs match term.  Any other term is interpreted as pattern and selects
  1025 all theorems matching the pattern. Available in ProofGeneral under
  1026 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  1027 
  1028   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  1029 
  1030 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  1031 matching the current goal as introduction rule and not having "HOL."
  1032 in their name (i.e. not being defined in theory HOL).
  1033 
  1034 * Command 'thms_containing' has been discontinued in favour of
  1035 'find_theorems'; INCOMPATIBILITY.
  1036 
  1037 * Communication with Proof General is now 8bit clean, which means that
  1038 Unicode text in UTF-8 encoding may be used within theory texts (both
  1039 formal and informal parts).  Cf. option -U of the Isabelle Proof
  1040 General interface.  Here are some simple examples (cf. src/HOL/ex):
  1041 
  1042   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  1043   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  1044 
  1045 * Improved efficiency of the Simplifier and, to a lesser degree, the
  1046 Classical Reasoner.  Typical big applications run around 2 times
  1047 faster.
  1048 
  1049 
  1050 *** Document preparation ***
  1051 
  1052 * Commands 'display_drafts' and 'print_drafts' perform simple output
  1053 of raw sources.  Only those symbols that do not require additional
  1054 LaTeX packages (depending on comments in isabellesym.sty) are
  1055 displayed properly, everything else is left verbatim.  isatool display
  1056 and isatool print are used as front ends (these are subject to the
  1057 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  1058 
  1059 * Command tags control specific markup of certain regions of text,
  1060 notably folding and hiding.  Predefined tags include "theory" (for
  1061 theory begin and end), "proof" for proof commands, and "ML" for
  1062 commands involving ML code; the additional tags "visible" and
  1063 "invisible" are unused by default.  Users may give explicit tag
  1064 specifications in the text, e.g. ''by %invisible (auto)''.  The
  1065 interpretation of tags is determined by the LaTeX job during document
  1066 preparation: see option -V of isatool usedir, or options -n and -t of
  1067 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  1068 \isadroptag.
  1069 
  1070 Several document versions may be produced at the same time via isatool
  1071 usedir (the generated index.html will link all of them).  Typical
  1072 specifications include ''-V document=theory,proof,ML'' to present
  1073 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  1074 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  1075 these parts without any formal replacement text.  The Isabelle site
  1076 default settings produce ''document'' and ''outline'' versions as
  1077 specified above.
  1078 
  1079 * Several new antiquotations:
  1080 
  1081   @{term_type term} prints a term with its type annotated;
  1082 
  1083   @{typeof term} prints the type of a term;
  1084 
  1085   @{const const} is the same as @{term const}, but checks that the
  1086   argument is a known logical constant;
  1087 
  1088   @{term_style style term} and @{thm_style style thm} print a term or
  1089   theorem applying a "style" to it
  1090 
  1091   @{ML text}
  1092 
  1093 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  1094 definitions, equations, inequations etc., 'concl' printing only the
  1095 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  1096 to print the specified premise.  TermStyle.add_style provides an ML
  1097 interface for introducing further styles.  See also the "LaTeX Sugar"
  1098 document practical applications.  The ML antiquotation prints
  1099 type-checked ML expressions verbatim.
  1100 
  1101 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  1102 and 'text' support optional locale specification '(in loc)', which
  1103 specifies the default context for interpreting antiquotations.  For
  1104 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  1105 
  1106 * Option 'locale=NAME' of antiquotations specifies an alternative
  1107 context interpreting the subsequent argument.  For example: @{thm
  1108 [locale=lattice] inf_assoc}.
  1109 
  1110 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  1111 a proof context.
  1112 
  1113 * Proper output of antiquotations for theory commands involving a
  1114 proof context (such as 'locale' or 'theorem (in loc) ...').
  1115 
  1116 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  1117 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  1118 
  1119 * isatool usedir: new option -C (default true) controls whether option
  1120 -D should include a copy of the original document directory; -C false
  1121 prevents unwanted effects such as copying of administrative CVS data.
  1122 
  1123 
  1124 *** Pure ***
  1125 
  1126 * Considerably improved version of 'constdefs' command.  Now performs
  1127 automatic type-inference of declared constants; additional support for
  1128 local structure declarations (cf. locales and HOL records), see also
  1129 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  1130 sequential dependencies of definitions within a single 'constdefs'
  1131 section; moreover, the declared name needs to be an identifier.  If
  1132 all fails, consider to fall back on 'consts' and 'defs' separately.
  1133 
  1134 * Improved indexed syntax and implicit structures.  First of all,
  1135 indexed syntax provides a notational device for subscripted
  1136 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  1137 expressions.  Secondly, in a local context with structure
  1138 declarations, number indexes \<^sub>n or the empty index (default
  1139 number 1) refer to a certain fixed variable implicitly; option
  1140 show_structs controls printing of implicit structures.  Typical
  1141 applications of these concepts involve record types and locales.
  1142 
  1143 * New command 'no_syntax' removes grammar declarations (and
  1144 translations) resulting from the given syntax specification, which is
  1145 interpreted in the same manner as for the 'syntax' command.
  1146 
  1147 * 'Advanced' translation functions (parse_translation etc.) may depend
  1148 on the signature of the theory context being presently used for
  1149 parsing/printing, see also isar-ref manual.
  1150 
  1151 * Improved 'oracle' command provides a type-safe interface to turn an
  1152 ML expression of type theory -> T -> term into a primitive rule of
  1153 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  1154 is already included here); see also FOL/ex/IffExample.thy;
  1155 INCOMPATIBILITY.
  1156 
  1157 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  1158 before); "cI" is no longer bound, use "c.intro" instead.
  1159 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  1160 axclasses vs. locales.
  1161 
  1162 * Improved internal renaming of symbolic identifiers -- attach primes
  1163 instead of base 26 numbers.
  1164 
  1165 * New flag show_question_marks controls printing of leading question
  1166 marks in schematic variable names.
  1167 
  1168 * In schematic variable names, *any* symbol following \<^isub> or
  1169 \<^isup> is now treated as part of the base name.  For example, the
  1170 following works without printing of awkward ".0" indexes:
  1171 
  1172   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  1173     by simp
  1174 
  1175 * Inner syntax includes (*(*nested*) comments*).
  1176 
  1177 * Pretty printer now supports unbreakable blocks, specified in mixfix
  1178 annotations as "(00...)".
  1179 
  1180 * Clear separation of logical types and nonterminals, where the latter
  1181 may only occur in 'syntax' specifications or type abbreviations.
  1182 Before that distinction was only partially implemented via type class
  1183 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  1184 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  1185 exotic syntax specifications may require further adaption
  1186 (e.g. Cube/Cube.thy).
  1187 
  1188 * Removed obsolete type class "logic", use the top sort {} instead.
  1189 Note that non-logical types should be declared as 'nonterminals'
  1190 rather than 'types'.  INCOMPATIBILITY for new object-logic
  1191 specifications.
  1192 
  1193 * Attributes 'induct' and 'cases': type or set names may now be
  1194 locally fixed variables as well.
  1195 
  1196 * Simplifier: can now control the depth to which conditional rewriting
  1197 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  1198 Limit.
  1199 
  1200 * Simplifier: simplification procedures may now take the current
  1201 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  1202 interface), which is very useful for calling the Simplifier
  1203 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  1204 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  1205 low-level mk_simproc no longer applies Logic.varify internally, to
  1206 allow for use in a context of fixed variables.
  1207 
  1208 * thin_tac now works even if the assumption being deleted contains !!
  1209 or ==>.  More generally, erule now works even if the major premise of
  1210 the elimination rule contains !! or ==>.
  1211 
  1212 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  1213 
  1214 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  1215 from Pure, which contains all common declarations already.  Both
  1216 theories are defined via plain Isabelle/Isar .thy files.
  1217 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  1218 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  1219 use isatool fixcpure to adapt your theory and ML sources.
  1220 
  1221 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  1222 selections of theorems in named facts via index ranges.
  1223 
  1224 * 'print_theorems': in theory mode, really print the difference
  1225 wrt. the last state (works for interactive theory development only),
  1226 in proof mode print all local facts (cf. 'print_facts');
  1227 
  1228 * 'hide': option '(open)' hides only base names.
  1229 
  1230 * More efficient treatment of intermediate checkpoints in interactive
  1231 theory development.
  1232 
  1233 * Code generator is now invoked via code_module (incremental code
  1234 generation) and code_library (modular code generation, ML structures
  1235 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  1236 must be quoted when used as identifiers.
  1237 
  1238 * New 'value' command for reading, evaluating and printing terms using
  1239 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  1240 quoted when used as identifier.
  1241 
  1242 
  1243 *** Locales ***
  1244 
  1245 * New commands for the interpretation of locale expressions in
  1246 theories (1), locales (2) and proof contexts (3).  These generate
  1247 proof obligations from the expression specification.  After the
  1248 obligations have been discharged, theorems of the expression are added
  1249 to the theory, target locale or proof context.  The synopsis of the
  1250 commands is a follows:
  1251 
  1252   (1) interpretation expr inst
  1253   (2) interpretation target < expr
  1254   (3) interpret expr inst
  1255 
  1256 Interpretation in theories and proof contexts require a parameter
  1257 instantiation of terms from the current context.  This is applied to
  1258 specifications and theorems of the interpreted expression.
  1259 Interpretation in locales only permits parameter renaming through the
  1260 locale expression.  Interpretation is smart in that interpretations
  1261 that are active already do not occur in proof obligations, neither are
  1262 instantiated theorems stored in duplicate.  Use 'print_interps' to
  1263 inspect active interpretations of a particular locale.  For details,
  1264 see the Isar Reference manual.  Examples can be found in
  1265 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  1266 
  1267 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  1268 'interpret' instead.
  1269 
  1270 * New context element 'constrains' for adding type constraints to
  1271 parameters.
  1272 
  1273 * Context expressions: renaming of parameters with syntax
  1274 redeclaration.
  1275 
  1276 * Locale declaration: 'includes' disallowed.
  1277 
  1278 * Proper static binding of attribute syntax -- i.e. types / terms /
  1279 facts mentioned as arguments are always those of the locale definition
  1280 context, independently of the context of later invocations.  Moreover,
  1281 locale operations (renaming and type / term instantiation) are applied
  1282 to attribute arguments as expected.
  1283 
  1284 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  1285 actual attributes; rare situations may require Attrib.attribute to
  1286 embed those attributes into Attrib.src that lack concrete syntax.
  1287 Attribute implementations need to cooperate properly with the static
  1288 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  1289 Attrib.XXX_thm etc. already do the right thing without further
  1290 intervention.  Only unusual applications -- such as "where" or "of"
  1291 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  1292 on the context and the facts involved -- may have to assign parsed
  1293 values to argument tokens explicitly.
  1294 
  1295 * Changed parameter management in theorem generation for long goal
  1296 statements with 'includes'.  INCOMPATIBILITY: produces a different
  1297 theorem statement in rare situations.
  1298 
  1299 * Locale inspection command 'print_locale' omits notes elements.  Use
  1300 'print_locale!' to have them included in the output.
  1301 
  1302 
  1303 *** Provers ***
  1304 
  1305 * Provers/hypsubst.ML: improved version of the subst method, for
  1306 single-step rewriting: it now works in bound variable contexts. New is
  1307 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  1308 rewrite a different subterm than the original subst method, which is
  1309 still available as 'simplesubst'.
  1310 
  1311 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  1312 and quasi orders.
  1313 
  1314 * Provers/trancl.ML: new transitivity reasoner for transitive and
  1315 reflexive-transitive closure of relations.
  1316 
  1317 * Provers/blast.ML: new reference depth_limit to make blast's depth
  1318 limit (previously hard-coded with a value of 20) user-definable.
  1319 
  1320 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  1321 is peformed already.  Object-logics merely need to finish their
  1322 initial simpset configuration as before.  INCOMPATIBILITY.
  1323 
  1324 
  1325 *** HOL ***
  1326 
  1327 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  1328 
  1329   syntax (epsilon)
  1330     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  1331 
  1332 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  1333 and x-symbol; use option '-m epsilon' to get it actually printed.
  1334 Moreover, the mathematically important symbolic identifier \<epsilon>
  1335 becomes available as variable, constant etc.  INCOMPATIBILITY,
  1336 
  1337 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  1338 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  1339 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  1340 support corresponding Isar calculations.
  1341 
  1342 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  1343 instead of ":".
  1344 
  1345 * theory SetInterval: changed the syntax for open intervals:
  1346 
  1347   Old       New
  1348   {..n(}    {..<n}
  1349   {)n..}    {n<..}
  1350   {m..n(}   {m..<n}
  1351   {)m..n}   {m<..n}
  1352   {)m..n(}  {m<..<n}
  1353 
  1354 The old syntax is still supported but will disappear in the next
  1355 release.  For conversion use the following Emacs search and replace
  1356 patterns (these are not perfect but work quite well):
  1357 
  1358   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  1359   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  1360 
  1361 * Theory Commutative_Ring (in Library): method comm_ring for proving
  1362 equalities in commutative rings; method 'algebra' provides a generic
  1363 interface.
  1364 
  1365 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  1366 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  1367 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  1368 be a tuple pattern.
  1369 
  1370 Some new syntax forms are available:
  1371 
  1372   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  1373   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  1374   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  1375   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  1376 
  1377 The latter form "\<Sum>x < k. e" used to be based on a separate
  1378 function "Summation", which has been discontinued.
  1379 
  1380 * theory Finite_Set: in structured induction proofs, the insert case
  1381 is now 'case (insert x F)' instead of the old counterintuitive 'case
  1382 (insert F x)'.
  1383 
  1384 * The 'refute' command has been extended to support a much larger
  1385 fragment of HOL, including axiomatic type classes, constdefs and
  1386 typedefs, inductive datatypes and recursion.
  1387 
  1388 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  1389 Requires zChaff with proof generation to be installed.  See
  1390 HOL/ex/SAT_Examples.thy for examples.
  1391 
  1392 * Datatype induction via method 'induct' now preserves the name of the
  1393 induction variable. For example, when proving P(xs::'a list) by
  1394 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  1395 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  1396 in unstructured proof scripts.
  1397 
  1398 * Reworked implementation of records.  Improved scalability for
  1399 records with many fields, avoiding performance problems for type
  1400 inference. Records are no longer composed of nested field types, but
  1401 of nested extension types. Therefore the record type only grows linear
  1402 in the number of extensions and not in the number of fields.  The
  1403 top-level (users) view on records is preserved.  Potential
  1404 INCOMPATIBILITY only in strange cases, where the theory depends on the
  1405 old record representation. The type generated for a record is called
  1406 <record_name>_ext_type.
  1407 
  1408 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  1409 proofs triggered by a record definition or a simproc (if
  1410 quick_and_dirty is enabled).  Definitions of large records can take
  1411 quite long.
  1412 
  1413 New simproc record_upd_simproc for simplification of multiple record
  1414 updates enabled by default.  Moreover, trivial updates are also
  1415 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  1416 occasionally, since simplification is more powerful by default.
  1417 
  1418 * typedef: proper support for polymorphic sets, which contain extra
  1419 type-variables in the term.
  1420 
  1421 * Simplifier: automatically reasons about transitivity chains
  1422 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  1423 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  1424 old proofs break occasionally as simplification may now solve more
  1425 goals than previously.
  1426 
  1427 * Simplifier: converts x <= y into x = y if assumption y <= x is
  1428 present.  Works for all partial orders (class "order"), in particular
  1429 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  1430 just like y <= x.
  1431 
  1432 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  1433 bound variable or a constant then the let is unfolded.  Otherwise
  1434 first a is simplified to b, and then f b is simplified to g. If
  1435 possible we abstract b from g arriving at "let x = b in h x",
  1436 otherwise we unfold the let and arrive at g.  The simproc can be
  1437 enabled/disabled by the reference use_let_simproc.  Potential
  1438 INCOMPATIBILITY since simplification is more powerful by default.
  1439 
  1440 * Classical reasoning: the meson method now accepts theorems as arguments.
  1441 
  1442 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  1443 jobs to provide advice on the provability of subgoals.
  1444 
  1445 * Theory OrderedGroup and Ring_and_Field: various additions and
  1446 improvements to faciliate calculations involving equalities and
  1447 inequalities.
  1448 
  1449 The following theorems have been eliminated or modified
  1450 (INCOMPATIBILITY):
  1451 
  1452   abs_eq             now named abs_of_nonneg
  1453   abs_of_ge_0        now named abs_of_nonneg
  1454   abs_minus_eq       now named abs_of_nonpos
  1455   imp_abs_id         now named abs_of_nonneg
  1456   imp_abs_neg_id     now named abs_of_nonpos
  1457   mult_pos           now named mult_pos_pos
  1458   mult_pos_le        now named mult_nonneg_nonneg
  1459   mult_pos_neg_le    now named mult_nonneg_nonpos
  1460   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  1461   mult_neg           now named mult_neg_neg
  1462   mult_neg_le        now named mult_nonpos_nonpos
  1463 
  1464 * Theory Parity: added rules for simplifying exponents.
  1465 
  1466 * Theory List:
  1467 
  1468 The following theorems have been eliminated or modified
  1469 (INCOMPATIBILITY):
  1470 
  1471   list_all_Nil       now named list_all.simps(1)
  1472   list_all_Cons      now named list_all.simps(2)
  1473   list_all_conv      now named list_all_iff
  1474   set_mem_eq         now named mem_iff
  1475 
  1476 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  1477 asymptotic "big O" calculations.  See the notes in BigO.thy.
  1478 
  1479 
  1480 *** HOL-Complex ***
  1481 
  1482 * Theory RealDef: better support for embedding natural numbers and
  1483 integers in the reals.
  1484 
  1485 The following theorems have been eliminated or modified
  1486 (INCOMPATIBILITY):
  1487 
  1488   exp_ge_add_one_self  now requires no hypotheses
  1489   real_of_int_add      reversed direction of equality (use [symmetric])
  1490   real_of_int_minus    reversed direction of equality (use [symmetric])
  1491   real_of_int_diff     reversed direction of equality (use [symmetric])
  1492   real_of_int_mult     reversed direction of equality (use [symmetric])
  1493 
  1494 * Theory RComplete: expanded support for floor and ceiling functions.
  1495 
  1496 * Theory Ln is new, with properties of the natural logarithm
  1497 
  1498 * Hyperreal: There is a new type constructor "star" for making
  1499 nonstandard types.  The old type names are now type synonyms:
  1500 
  1501   hypreal = real star
  1502   hypnat = nat star
  1503   hcomplex = complex star
  1504 
  1505 * Hyperreal: Many groups of similarly-defined constants have been
  1506 replaced by polymorphic versions (INCOMPATIBILITY):
  1507 
  1508   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  1509 
  1510   starset      <-- starsetNat, starsetC
  1511   *s*          <-- *sNat*, *sc*
  1512   starset_n    <-- starsetNat_n, starsetC_n
  1513   *sn*         <-- *sNatn*, *scn*
  1514   InternalSets <-- InternalNatSets, InternalCSets
  1515 
  1516   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  1517   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  1518   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  1519   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  1520   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  1521 
  1522 * Hyperreal: Many type-specific theorems have been removed in favor of
  1523 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  1524 
  1525   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  1526   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  1527   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  1528   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  1529   right_minus <-- hypreal_add_minus
  1530   left_minus <-- {hypreal,hcomplex}_add_minus_left
  1531   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  1532   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  1533   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  1534   mult_1_right <-- hcomplex_mult_one_right
  1535   mult_zero_left <-- hcomplex_mult_zero_left
  1536   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  1537   right_distrib <-- hypnat_add_mult_distrib2
  1538   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  1539   right_inverse <-- hypreal_mult_inverse
  1540   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  1541   order_refl <-- {hypreal,hypnat}_le_refl
  1542   order_trans <-- {hypreal,hypnat}_le_trans
  1543   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  1544   order_less_le <-- {hypreal,hypnat}_less_le
  1545   linorder_linear <-- {hypreal,hypnat}_le_linear
  1546   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  1547   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  1548   add_nonneg_nonneg <-- hypreal_le_add_order
  1549 
  1550 * Hyperreal: Separate theorems having to do with type-specific
  1551 versions of constants have been merged into theorems that apply to the
  1552 new polymorphic constants (INCOMPATIBILITY):
  1553 
  1554   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  1555   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  1556   STAR_Un <-- {STAR,NatStar,STARC}_Un
  1557   STAR_Int <-- {STAR,NatStar,STARC}_Int
  1558   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  1559   STAR_subset <-- {STAR,NatStar,STARC}_subset
  1560   STAR_mem <-- {STAR,NatStar,STARC}_mem
  1561   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  1562   STAR_diff <-- {STAR,STARC}_diff
  1563   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  1564     STARC_hcomplex_of_complex}_image_subset
  1565   starset_n_Un <-- starset{Nat,C}_n_Un
  1566   starset_n_Int <-- starset{Nat,C}_n_Int
  1567   starset_n_Compl <-- starset{Nat,C}_n_Compl
  1568   starset_n_diff <-- starset{Nat,C}_n_diff
  1569   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  1570   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  1571   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  1572   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  1573   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  1574   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  1575   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  1576   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  1577   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  1578   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  1579   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  1580   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  1581   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  1582   starfun_diff <-- starfun{C,RC,CR}_diff
  1583   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  1584   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  1585   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  1586   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  1587   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  1588   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  1589   starfun_Id <-- starfunC_Id
  1590   starfun_approx <-- starfun{Nat,CR}_approx
  1591   starfun_capprox <-- starfun{C,RC}_capprox
  1592   starfun_abs <-- starfunNat_rabs
  1593   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  1594   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  1595   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  1596   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  1597   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  1598   starfun_add_approx <-- starfunCR_add_approx
  1599   starfun_inverse_inverse <-- starfunC_inverse_inverse
  1600   starfun_divide <-- starfun{C,CR,RC}_divide
  1601   starfun_n <-- starfun{Nat,C}_n
  1602   starfun_n_mult <-- starfun{Nat,C}_n_mult
  1603   starfun_n_add <-- starfun{Nat,C}_n_add
  1604   starfun_n_add_minus <-- starfunNat_n_add_minus
  1605   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  1606   starfun_n_minus <-- starfun{Nat,C}_n_minus
  1607   starfun_n_eq <-- starfun{Nat,C}_n_eq
  1608 
  1609   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  1610   star_n_minus <-- {hypreal,hcomplex}_minus
  1611   star_n_diff <-- {hypreal,hcomplex}_diff
  1612   star_n_mult <-- {hypreal,hcomplex}_mult
  1613   star_n_inverse <-- {hypreal,hcomplex}_inverse
  1614   star_n_le <-- {hypreal,hypnat}_le
  1615   star_n_less <-- {hypreal,hypnat}_less
  1616   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  1617   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  1618   star_n_abs <-- hypreal_hrabs
  1619   star_n_divide <-- hcomplex_divide
  1620 
  1621   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  1622   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  1623   star_of_diff <-- hypreal_of_real_diff
  1624   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  1625   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  1626   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  1627   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  1628   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  1629   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  1630   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  1631   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  1632   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  1633   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  1634   star_of_number_of <-- {hypreal,hcomplex}_number_of
  1635   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  1636   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  1637   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  1638   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  1639   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  1640   star_of_power <-- hypreal_of_real_power
  1641   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  1642 
  1643 * Hyperreal: new method "transfer" that implements the transfer
  1644 principle of nonstandard analysis. With a subgoal that mentions
  1645 nonstandard types like "'a star", the command "apply transfer"
  1646 replaces it with an equivalent one that mentions only standard types.
  1647 To be successful, all free variables must have standard types; non-
  1648 standard variables must have explicit universal quantifiers.
  1649 
  1650 * Hyperreal: A theory of Taylor series.
  1651 
  1652 
  1653 *** HOLCF ***
  1654 
  1655 * Discontinued special version of 'constdefs' (which used to support
  1656 continuous functions) in favor of the general Pure one with full
  1657 type-inference.
  1658 
  1659 * New simplification procedure for solving continuity conditions; it
  1660 is much faster on terms with many nested lambda abstractions (cubic
  1661 instead of exponential time).
  1662 
  1663 * New syntax for domain package: selector names are now optional.
  1664 Parentheses should be omitted unless argument is lazy, for example:
  1665 
  1666   domain 'a stream = cons "'a" (lazy "'a stream")
  1667 
  1668 * New command 'fixrec' for defining recursive functions with pattern
  1669 matching; defining multiple functions with mutual recursion is also
  1670 supported.  Patterns may include the constants cpair, spair, up, sinl,
  1671 sinr, or any data constructor defined by the domain package. The given
  1672 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  1673 syntax and examples.
  1674 
  1675 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  1676 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  1677 but the proof obligation additionally includes an admissibility
  1678 requirement. The packages generate instances of class cpo or pcpo,
  1679 with continuity and strictness theorems for Rep and Abs.
  1680 
  1681 * HOLCF: Many theorems have been renamed according to a more standard naming
  1682 scheme (INCOMPATIBILITY):
  1683 
  1684   foo_inject:  "foo$x = foo$y ==> x = y"
  1685   foo_eq:      "(foo$x = foo$y) = (x = y)"
  1686   foo_less:    "(foo$x << foo$y) = (x << y)"
  1687   foo_strict:  "foo$UU = UU"
  1688   foo_defined: "... ==> foo$x ~= UU"
  1689   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  1690 
  1691 
  1692 *** ZF ***
  1693 
  1694 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  1695 including the First Isomorphism Theorem (on quotienting by the kernel
  1696 of a homomorphism).
  1697 
  1698 * ZF/Simplifier: install second copy of type solver that actually
  1699 makes use of TC rules declared to Isar proof contexts (or locales);
  1700 the old version is still required for ML proof scripts.
  1701 
  1702 
  1703 *** Cube ***
  1704 
  1705 * Converted to Isar theory format; use locales instead of axiomatic
  1706 theories.
  1707 
  1708 
  1709 *** ML ***
  1710 
  1711 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  1712 for ||>, ||>>, |>>,
  1713 
  1714 * Pure/library.ML no longer defines its own option datatype, but uses
  1715 that of the SML basis, which has constructors NONE and SOME instead of
  1716 None and Some, as well as exception Option.Option instead of OPTION.
  1717 The functions the, if_none, is_some, is_none have been adapted
  1718 accordingly, while Option.map replaces apsome.
  1719 
  1720 * Pure/library.ML: the exception LIST has been given up in favour of
  1721 the standard exceptions Empty and Subscript, as well as
  1722 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  1723 superceded by the standard hd and tl functions etc.
  1724 
  1725 A number of basic list functions are no longer exported to the ML
  1726 toplevel, as they are variants of predefined functions.  The following
  1727 suggests how one can translate existing code:
  1728 
  1729     rev_append xs ys = List.revAppend (xs, ys)
  1730     nth_elem (i, xs) = List.nth (xs, i)
  1731     last_elem xs = List.last xs
  1732     flat xss = List.concat xss
  1733     seq fs = List.app fs
  1734     partition P xs = List.partition P xs
  1735     mapfilter f xs = List.mapPartial f xs
  1736 
  1737 * Pure/library.ML: several combinators for linear functional
  1738 transformations, notably reverse application and composition:
  1739 
  1740   x |> f                f #> g
  1741   (x, y) |-> f          f #-> g
  1742 
  1743 * Pure/library.ML: introduced/changed precedence of infix operators:
  1744 
  1745   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  1746   infix 2 ?;
  1747   infix 3 o oo ooo oooo;
  1748   infix 4 ~~ upto downto;
  1749 
  1750 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  1751 infix operators.
  1752 
  1753 * Pure/library.ML: natural list combinators fold, fold_rev, and
  1754 fold_map support linear functional transformations and nesting.  For
  1755 example:
  1756 
  1757   fold f [x1, ..., xN] y =
  1758     y |> f x1 |> ... |> f xN
  1759 
  1760   (fold o fold) f [xs1, ..., xsN] y =
  1761     y |> fold f xs1 |> ... |> fold f xsN
  1762 
  1763   fold f [x1, ..., xN] =
  1764     f x1 #> ... #> f xN
  1765 
  1766   (fold o fold) f [xs1, ..., xsN] =
  1767     fold f xs1 #> ... #> fold f xsN
  1768 
  1769 * Pure/library.ML: the following selectors on type 'a option are
  1770 available:
  1771 
  1772   the:               'a option -> 'a  (*partial*)
  1773   these:             'a option -> 'a  where 'a = 'b list
  1774   the_default: 'a -> 'a option -> 'a
  1775   the_list:          'a option -> 'a list
  1776 
  1777 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  1778 basic operations for association lists, following natural argument
  1779 order; moreover the explicit equality predicate passed here avoids
  1780 potentially expensive polymorphic runtime equality checks.
  1781 The old functions may be expressed as follows:
  1782 
  1783   assoc = uncurry (AList.lookup (op =))
  1784   assocs = these oo AList.lookup (op =)
  1785   overwrite = uncurry (AList.update (op =)) o swap
  1786 
  1787 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  1788 
  1789   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  1790   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  1791 
  1792 replacing make_keylist and keyfilter (occassionally used)
  1793 Naive rewrites:
  1794 
  1795   make_keylist = AList.make
  1796   keyfilter = AList.find (op =)
  1797 
  1798 * eq_fst and eq_snd now take explicit equality parameter, thus
  1799   avoiding eqtypes. Naive rewrites:
  1800 
  1801     eq_fst = eq_fst (op =)
  1802     eq_snd = eq_snd (op =)
  1803 
  1804 * Removed deprecated apl and apr (rarely used).
  1805   Naive rewrites:
  1806 
  1807     apl (n, op) =>>= curry op n
  1808     apr (op, m) =>>= fn n => op (n, m)
  1809 
  1810 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  1811 provides a reasonably efficient light-weight implementation of sets as
  1812 lists.
  1813 
  1814 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  1815 few new operations; existing lookup and update are now curried to
  1816 follow natural argument order (for use with fold etc.);
  1817 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  1818 
  1819 * Pure/General: output via the Isabelle channels of
  1820 writeln/warning/error etc. is now passed through Output.output, with a
  1821 hook for arbitrary transformations depending on the print_mode
  1822 (cf. Output.add_mode -- the first active mode that provides a output
  1823 function wins).  Already formatted output may be embedded into further
  1824 text via Output.raw; the result of Pretty.string_of/str_of and derived
  1825 functions (string_of_term/cterm/thm etc.) is already marked raw to
  1826 accommodate easy composition of diagnostic messages etc.  Programmers
  1827 rarely need to care about Output.output or Output.raw at all, with
  1828 some notable exceptions: Output.output is required when bypassing the
  1829 standard channels (writeln etc.), or in token translations to produce
  1830 properly formatted results; Output.raw is required when capturing
  1831 already output material that will eventually be presented to the user
  1832 a second time.  For the default print mode, both Output.output and
  1833 Output.raw have no effect.
  1834 
  1835 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  1836 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  1837 cumulative results are displayed at the end of a batch session.
  1838 
  1839 * Pure/General: File.sysify_path and File.quote_sysify path have been
  1840 replaced by File.platform_path and File.shell_path (with appropriate
  1841 hooks).  This provides a clean interface for unusual systems where the
  1842 internal and external process view of file names are different.
  1843 
  1844 * Pure: more efficient orders for basic syntactic entities: added
  1845 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  1846 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  1847 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  1848 orders now -- potential INCOMPATIBILITY for code that depends on a
  1849 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  1850 Library.sort_strings on result).
  1851 
  1852 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  1853 fold_types traverse types/terms from left to right, observing natural
  1854 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  1855 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  1856 
  1857 * Pure: name spaces have been refined, with significant changes of the
  1858 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  1859 to extern(_table).  The plain name entry path is superceded by a
  1860 general 'naming' context, which also includes the 'policy' to produce
  1861 a fully qualified name and external accesses of a fully qualified
  1862 name; NameSpace.extend is superceded by context dependent
  1863 Sign.declare_name.  Several theory and proof context operations modify
  1864 the naming context.  Especially note Theory.restore_naming and
  1865 ProofContext.restore_naming to get back to a sane state; note that
  1866 Theory.add_path is no longer sufficient to recover from
  1867 Theory.absolute_path in particular.
  1868 
  1869 * Pure: new flags short_names (default false) and unique_names
  1870 (default true) for controlling output of qualified names.  If
  1871 short_names is set, names are printed unqualified.  If unique_names is
  1872 reset, the name prefix is reduced to the minimum required to achieve
  1873 the original result when interning again, even if there is an overlap
  1874 with earlier declarations.
  1875 
  1876 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  1877 now 'extend', and 'merge' gets an additional Pretty.pp argument
  1878 (useful for printing error messages).  INCOMPATIBILITY.
  1879 
  1880 * Pure: major reorganization of the theory context.  Type Sign.sg and
  1881 Theory.theory are now identified, referring to the universal
  1882 Context.theory (see Pure/context.ML).  Actual signature and theory
  1883 content is managed as theory data.  The old code and interfaces were
  1884 spread over many files and structures; the new arrangement introduces
  1885 considerable INCOMPATIBILITY to gain more clarity:
  1886 
  1887   Context -- theory management operations (name, identity, inclusion,
  1888     parents, ancestors, merge, etc.), plus generic theory data;
  1889 
  1890   Sign -- logical signature and syntax operations (declaring consts,
  1891     types, etc.), plus certify/read for common entities;
  1892 
  1893   Theory -- logical theory operations (stating axioms, definitions,
  1894     oracles), plus a copy of logical signature operations (consts,
  1895     types, etc.); also a few basic management operations (Theory.copy,
  1896     Theory.merge, etc.)
  1897 
  1898 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  1899 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  1900 for convenience -- they merely return the theory.
  1901 
  1902 * Pure: type Type.tsig is superceded by theory in most interfaces.
  1903 
  1904 * Pure: the Isar proof context type is already defined early in Pure
  1905 as Context.proof (note that ProofContext.context and Proof.context are
  1906 aliases, where the latter is the preferred name).  This enables other
  1907 Isabelle components to refer to that type even before Isar is present.
  1908 
  1909 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  1910 typeK, constK, axiomK, oracleK), but provide explicit operations for
  1911 any of these kinds.  For example, Sign.intern typeK is now
  1912 Sign.intern_type, Theory.hide_space Sign.typeK is now
  1913 Theory.hide_types.  Also note that former
  1914 Theory.hide_classes/types/consts are now
  1915 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  1916 internalize their arguments!  INCOMPATIBILITY.
  1917 
  1918 * Pure: get_thm interface (of PureThy and ProofContext) expects
  1919 datatype thmref (with constructors Name and NameSelection) instead of
  1920 plain string -- INCOMPATIBILITY;
  1921 
  1922 * Pure: cases produced by proof methods specify options, where NONE
  1923 means to remove case bindings -- INCOMPATIBILITY in
  1924 (RAW_)METHOD_CASES.
  1925 
  1926 * Pure: the following operations retrieve axioms or theorems from a
  1927 theory node or theory hierarchy, respectively:
  1928 
  1929   Theory.axioms_of: theory -> (string * term) list
  1930   Theory.all_axioms_of: theory -> (string * term) list
  1931   PureThy.thms_of: theory -> (string * thm) list
  1932   PureThy.all_thms_of: theory -> (string * thm) list
  1933 
  1934 * Pure: print_tac now outputs the goal through the trace channel.
  1935 
  1936 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  1937 Reference Toplevel.debug (default false) controls detailed printing
  1938 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  1939 controls execution profiling -- set to 1 for time and 2 for space
  1940 (both increase the runtime).
  1941 
  1942 * Isar session: The initial use of ROOT.ML is now always timed,
  1943 i.e. the log will show the actual process times, in contrast to the
  1944 elapsed wall-clock time that the outer shell wrapper produces.
  1945 
  1946 * Simplifier: improved handling of bound variables (nameless
  1947 representation, avoid allocating new strings).  Simprocs that invoke
  1948 the Simplifier recursively should use Simplifier.inherit_bounds to
  1949 avoid local name clashes.  Failure to do so produces warnings
  1950 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  1951 for further details.
  1952 
  1953 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  1954 bindings for all theorems stored within a given theory; this may help
  1955 in porting non-Isar theories to Isar ones, while keeping ML proof
  1956 scripts for the time being.
  1957 
  1958 * ML operator HTML.with_charset specifies the charset begin used for
  1959 generated HTML files.  For example:
  1960 
  1961   HTML.with_charset "utf-8" use_thy "Hebrew";
  1962   HTML.with_charset "utf-8" use_thy "Chinese";
  1963 
  1964 
  1965 *** System ***
  1966 
  1967 * Allow symlinks to all proper Isabelle executables (Isabelle,
  1968 isabelle, isatool etc.).
  1969 
  1970 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  1971 isatool doc, isatool mkdir, display_drafts etc.).
  1972 
  1973 * isatool usedir: option -f allows specification of the ML file to be
  1974 used by Isabelle; default is ROOT.ML.
  1975 
  1976 * New isatool version outputs the version identifier of the Isabelle
  1977 distribution being used.
  1978 
  1979 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  1980 (containing Boolean satisfiability problems) into Isabelle/HOL
  1981 theories.
  1982 
  1983 
  1984 
  1985 New in Isabelle2004 (April 2004)
  1986 --------------------------------
  1987 
  1988 *** General ***
  1989 
  1990 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  1991   Replaces linorder.ML.
  1992 
  1993 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  1994   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  1995   (\<a>...\<z>), are now considered normal letters, and can therefore
  1996   be used anywhere where an ASCII letter (a...zA...Z) has until
  1997   now. COMPATIBILITY: This obviously changes the parsing of some
  1998   terms, especially where a symbol has been used as a binder, say
  1999   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  2000   as an identifier.  Fix it by inserting a space around former
  2001   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  2002   existing theory and ML files.
  2003 
  2004 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  2005 
  2006 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  2007   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  2008   a normal (but invisible) letter. For multiple letter subscripts repeat
  2009   \<^isub> like this: x\<^isub>1\<^isub>2.
  2010 
  2011 * Pure: There are now sub-/superscripts that can span more than one
  2012   character. Text between \<^bsub> and \<^esub> is set in subscript in
  2013   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  2014   superscript. The new control characters are not identifier parts.
  2015 
  2016 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  2017   content of "..." to the latex file instead of \isacntrl... . The "..."
  2018   may consist of any printable characters excluding the end bracket >.
  2019 
  2020 * Pure: Using new Isar command "finalconsts" (or the ML functions
  2021   Theory.add_finals or Theory.add_finals_i) it is now possible to
  2022   declare constants "final", which prevents their being given a definition
  2023   later.  It is useful for constants whose behaviour is fixed axiomatically
  2024   rather than definitionally, such as the meta-logic connectives.
  2025 
  2026 * Pure: 'instance' now handles general arities with general sorts
  2027   (i.e. intersections of classes),
  2028 
  2029 * Presentation: generated HTML now uses a CSS style sheet to make layout
  2030   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  2031   It can be changed to alter the colors/layout of generated pages.
  2032 
  2033 
  2034 *** Isar ***
  2035 
  2036 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  2037   cut_tac, subgoal_tac and thin_tac:
  2038   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  2039     locales are no longer forced to write Isar proof scripts.
  2040     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  2041     emulations.
  2042   - INCOMPATIBILITY: names of variables to be instantiated may no
  2043     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  2044     This is consistent with the instantiation attribute "where".
  2045 
  2046 * Attributes "where" and "of":
  2047   - Now take type variables of instantiated theorem into account when reading
  2048     the instantiation string.  This fixes a bug that caused instantiated
  2049     theorems to have too special types in some circumstances.
  2050   - "where" permits explicit instantiations of type variables.
  2051 
  2052 * Calculation commands "moreover" and "also" no longer interfere with
  2053   current facts ("this"), admitting arbitrary combinations with "then"
  2054   and derived forms.
  2055 
  2056 * Locales:
  2057   - Goal statements involving the context element "includes" no longer
  2058     generate theorems with internal delta predicates (those ending on
  2059     "_axioms") in the premise.
  2060     Resolve particular premise with <locale>.intro to obtain old form.
  2061   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  2062     specification and "includes" elements in goal statement.
  2063   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  2064     [intro?] and [elim?] (respectively) by default.
  2065   - Experimental command for instantiation of locales in proof contexts:
  2066         instantiate <label>[<attrs>]: <loc>
  2067     Instantiates locale <loc> and adds all its theorems to the current context
  2068     taking into account their attributes.  Label and attrs are optional
  2069     modifiers, like in theorem declarations.  If present, names of
  2070     instantiated theorems are qualified with <label>, and the attributes
  2071     <attrs> are applied after any attributes these theorems might have already.
  2072       If the locale has assumptions, a chained fact of the form
  2073     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  2074     are derived.  The command does not support old-style locales declared
  2075     with "locale (open)".
  2076       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  2077 
  2078 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  2079   (Isar) contexts.
  2080 
  2081 
  2082 *** HOL ***
  2083 
  2084 * Proof import: new image HOL4 contains the imported library from
  2085   the HOL4 system with about 2500 theorems. It is imported by
  2086   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  2087   can be used like any other Isabelle image.  See
  2088   HOL/Import/HOL/README for more information.
  2089 
  2090 * Simplifier:
  2091   - Much improved handling of linear and partial orders.
  2092     Reasoners for linear and partial orders are set up for type classes
  2093     "linorder" and "order" respectively, and are added to the default simpset
  2094     as solvers.  This means that the simplifier can build transitivity chains
  2095     to solve goals from the assumptions.
  2096   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  2097     of blast or auto after simplification become unnecessary because the goal
  2098     is solved by simplification already.
  2099 
  2100 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  2101     all proved in axiomatic type classes for semirings, rings and fields.
  2102 
  2103 * Numerics:
  2104   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  2105     now formalized using the Ring_and_Field theory mentioned above.
  2106   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  2107     than before, because now they are set up once in a generic manner.
  2108   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  2109     Look for the general versions in Ring_and_Field (and Power if they concern
  2110     exponentiation).
  2111 
  2112 * Type "rat" of the rational numbers is now available in HOL-Complex.
  2113 
  2114 * Records:
  2115   - Record types are now by default printed with their type abbreviation
  2116     instead of the list of all field types. This can be configured via
  2117     the reference "print_record_type_abbr".
  2118   - Simproc "record_upd_simproc" for simplification of multiple updates added
  2119     (not enabled by default).
  2120   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  2121     EX x. x = sel r to True (not enabled by default).
  2122   - Tactic "record_split_simp_tac" to split and simplify records added.
  2123 
  2124 * 'specification' command added, allowing for definition by
  2125   specification.  There is also an 'ax_specification' command that
  2126   introduces the new constants axiomatically.
  2127 
  2128 * arith(_tac) is now able to generate counterexamples for reals as well.
  2129 
  2130 * HOL-Algebra: new locale "ring" for non-commutative rings.
  2131 
  2132 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  2133   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  2134 
  2135 * HOL-Matrix: a first theory for matrices in HOL with an application of
  2136   matrix theory to linear programming.
  2137 
  2138 * Unions and Intersections:
  2139   The latex output syntax of UN and INT has been changed
  2140   from "\Union x \in A. B" to "\Union_{x \in A} B"
  2141   i.e. the index formulae has become a subscript.
  2142   Similarly for "\Union x. B", and for \Inter instead of \Union.
  2143 
  2144 * Unions and Intersections over Intervals:
  2145   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  2146   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  2147   like in normal math, and corresponding versions for < and for intersection.
  2148 
  2149 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  2150   lexicographic dictonary ordering has been added as "lexord".
  2151 
  2152 * ML: the legacy theory structures Int and List have been removed. They had
  2153   conflicted with ML Basis Library structures having the same names.
  2154 
  2155 * 'refute' command added to search for (finite) countermodels.  Only works
  2156   for a fragment of HOL.  The installation of an external SAT solver is
  2157   highly recommended.  See "HOL/Refute.thy" for details.
  2158 
  2159 * 'quickcheck' command: Allows to find counterexamples by evaluating
  2160   formulae under an assignment of free variables to random values.
  2161   In contrast to 'refute', it can deal with inductive datatypes,
  2162   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  2163   for examples.
  2164 
  2165 
  2166 *** HOLCF ***
  2167 
  2168 * Streams now come with concatenation and are part of the HOLCF image
  2169 
  2170 
  2171 
  2172 New in Isabelle2003 (May 2003)
  2173 ------------------------------
  2174 
  2175 *** General ***
  2176 
  2177 * Provers/simplifier:
  2178 
  2179   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  2180     Assumptions are now subject to complete mutual simplification,
  2181     not just from left to right. The simplifier now preserves
  2182     the order of assumptions.
  2183 
  2184     Potential INCOMPATIBILITY:
  2185 
  2186     -- simp sometimes diverges where the old version did
  2187        not, e.g. invoking simp on the goal
  2188 
  2189         [| P (f x); y = x; f x = f y |] ==> Q
  2190 
  2191        now gives rise to the infinite reduction sequence
  2192 
  2193         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  2194 
  2195        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  2196        kind of problem.
  2197 
  2198     -- Tactics combining classical reasoner and simplification (such as auto)
  2199        are also affected by this change, because many of them rely on
  2200        simp. They may sometimes diverge as well or yield a different numbers
  2201        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  2202        in case of problems. Sometimes subsequent calls to the classical
  2203        reasoner will fail because a preceeding call to the simplifier too
  2204        eagerly simplified the goal, e.g. deleted redundant premises.
  2205 
  2206   - The simplifier trace now shows the names of the applied rewrite rules
  2207 
  2208   - You can limit the number of recursive invocations of the simplifier
  2209     during conditional rewriting (where the simplifie tries to solve the
  2210     conditions before applying the rewrite rule):
  2211     ML "simp_depth_limit := n"
  2212     where n is an integer. Thus you can force termination where previously
  2213     the simplifier would diverge.
  2214 
  2215   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  2216 
  2217   - No longer aborts on failed congruence proof.  Instead, the
  2218     congruence is ignored.
  2219 
  2220 * Pure: New generic framework for extracting programs from constructive
  2221   proofs. See HOL/Extraction.thy for an example instantiation, as well
  2222   as HOL/Extraction for some case studies.
  2223 
  2224 * Pure: The main goal of the proof state is no longer shown by default, only
  2225 the subgoals. This behaviour is controlled by a new flag.
  2226    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  2227 (ML: Proof.show_main_goal).
  2228 
  2229 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  2230 rules whose conclusion matches subgoal 1:
  2231       PG menu: Isabelle/Isar -> Show me -> matching rules
  2232 The rules are ordered by how closely they match the subgoal.
  2233 In particular, rules that solve a subgoal outright are displayed first
  2234 (or rather last, the way they are printed).
  2235 (ML: ProofGeneral.print_intros())
  2236 
  2237 * Pure: New flag trace_unify_fail causes unification to print
  2238 diagnostic information (PG: in trace buffer) when it fails. This is
  2239 useful for figuring out why single step proofs like rule, erule or
  2240 assumption failed.
  2241 
  2242 * Pure: Locale specifications now produce predicate definitions
  2243 according to the body of text (covering assumptions modulo local
  2244 definitions); predicate "loc_axioms" covers newly introduced text,
  2245 while "loc" is cumulative wrt. all included locale expressions; the
  2246 latter view is presented only on export into the global theory
  2247 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  2248 on the old view without predicates;
  2249 
  2250 * Pure: predefined locales "var" and "struct" are useful for sharing
  2251 parameters (as in CASL, for example); just specify something like
  2252 ``var x + var y + struct M'' as import;
  2253 
  2254 * Pure: improved thms_containing: proper indexing of facts instead of
  2255 raw theorems; check validity of results wrt. current name space;
  2256 include local facts of proof configuration (also covers active
  2257 locales), cover fixed variables in index; may use "_" in term
  2258 specification; an optional limit for the number of printed facts may
  2259 be given (the default is 40);
  2260 
  2261 * Pure: disallow duplicate fact bindings within new-style theory files
  2262 (batch-mode only);
  2263 
  2264 * Provers: improved induct method: assumptions introduced by case
  2265 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  2266 the goal statement); "foo" still refers to all facts collectively;
  2267 
  2268 * Provers: the function blast.overloaded has been removed: all constants
  2269 are regarded as potentially overloaded, which improves robustness in exchange
  2270 for slight decrease in efficiency;
  2271 
  2272 * Provers/linorder: New generic prover for transitivity reasoning over
  2273 linear orders.  Note: this prover is not efficient!
  2274 
  2275 * Isar: preview of problems to finish 'show' now produce an error
  2276 rather than just a warning (in interactive mode);
  2277 
  2278 
  2279 *** HOL ***
  2280 
  2281 * arith(_tac)
  2282 
  2283  - Produces a counter example if it cannot prove a goal.
  2284    Note that the counter example may be spurious if the goal is not a formula
  2285    of quantifier-free linear arithmetic.
  2286    In ProofGeneral the counter example appears in the trace buffer.
  2287 
  2288  - Knows about div k and mod k where k is a numeral of type nat or int.
  2289 
  2290  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  2291    linear arithmetic fails. This takes account of quantifiers and divisibility.
  2292    Presburger arithmetic can also be called explicitly via presburger(_tac).
  2293 
  2294 * simp's arithmetic capabilities have been enhanced a bit: it now
  2295 takes ~= in premises into account (by performing a case split);
  2296 
  2297 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  2298 are distributed over a sum of terms;
  2299 
  2300 * New tactic "trans_tac" and method "trans" instantiate
  2301 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  2302 "<=", "<" and "=").
  2303 
  2304 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  2305 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  2306 
  2307 * 'typedef' command has new option "open" to suppress the set
  2308 definition;
  2309 
  2310 * functions Min and Max on finite sets have been introduced (theory
  2311 Finite_Set);
  2312 
  2313 * attribute [symmetric] now works for relations as well; it turns
  2314 (x,y) : R^-1 into (y,x) : R, and vice versa;
  2315 
  2316 * induct over a !!-quantified statement (say !!x1..xn):
  2317   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  2318 
  2319 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  2320 %x. None. Warning: empty_def now refers to the previously hidden definition
  2321 of the empty set.
  2322 
  2323 * Algebra: formalization of classical algebra.  Intended as base for
  2324 any algebraic development in Isabelle.  Currently covers group theory
  2325 (up to Sylow's theorem) and ring theory (Universal Property of
  2326 Univariate Polynomials).  Contributions welcome;
  2327 
  2328 * GroupTheory: deleted, since its material has been moved to Algebra;
  2329 
  2330 * Complex: new directory of the complex numbers with numeric constants,
  2331 nonstandard complex numbers, and some complex analysis, standard and
  2332 nonstandard (Jacques Fleuriot);
  2333 
  2334 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  2335 
  2336 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  2337 Fleuriot);
  2338 
  2339 * Real/HahnBanach: updated and adapted to locales;
  2340 
  2341 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  2342 Gray and Kramer);
  2343 
  2344 * UNITY: added the Meier-Sanders theory of progress sets;
  2345 
  2346 * MicroJava: bytecode verifier and lightweight bytecode verifier
  2347 as abstract algorithms, instantiated to the JVM;
  2348 
  2349 * Bali: Java source language formalization. Type system, operational
  2350 semantics, axiomatic semantics. Supported language features:
  2351 classes, interfaces, objects,virtual methods, static methods,
  2352 static/instance fields, arrays, access modifiers, definite
  2353 assignment, exceptions.
  2354 
  2355 
  2356 *** ZF ***
  2357 
  2358 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  2359 universe, etc.);
  2360 
  2361 * Main ZF: virtually all theories converted to new-style format;
  2362 
  2363 
  2364 *** ML ***
  2365 
  2366 * Pure: Tactic.prove provides sane interface for internal proofs;
  2367 omits the infamous "standard" operation, so this is more appropriate
  2368 than prove_goalw_cterm in many situations (e.g. in simprocs);
  2369 
  2370 * Pure: improved error reporting of simprocs;
  2371 
  2372 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  2373 up simprocs;
  2374 
  2375 
  2376 *** Document preparation ***
  2377 
  2378 * uses \par instead of \\ for line breaks in theory text. This may
  2379 shift some page breaks in large documents. To get the old behaviour
  2380 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  2381 
  2382 * minimized dependencies of isabelle.sty and isabellesym.sty on
  2383 other packages
  2384 
  2385 * \<euro> now needs package babel/greek instead of marvosym (which
  2386 broke \Rightarrow)
  2387 
  2388 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  2389 textcomp package)
  2390 
  2391 
  2392 
  2393 New in Isabelle2002 (March 2002)
  2394 --------------------------------
  2395 
  2396 *** Document preparation ***
  2397 
  2398 * greatly simplified document preparation setup, including more
  2399 graceful interpretation of isatool usedir -i/-d/-D options, and more
  2400 instructive isatool mkdir; users should basically be able to get
  2401 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  2402 users may run a separate document processing stage manually like this:
  2403 "isatool usedir -D output HOL Test && isatool document Test/output";
  2404 
  2405 * theory dependency graph may now be incorporated into documents;
  2406 isatool usedir -g true will produce session_graph.eps/.pdf for use
  2407 with \includegraphics of LaTeX;
  2408 
  2409 * proper spacing of consecutive markup elements, especially text
  2410 blocks after section headings;
  2411 
  2412 * support bold style (for single symbols only), input syntax is like
  2413 this: "\<^bold>\<alpha>" or "\<^bold>A";
  2414 
  2415 * \<bullet> is now output as bold \cdot by default, which looks much
  2416 better in printed text;
  2417 
  2418 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  2419 note that these symbols are currently unavailable in Proof General /
  2420 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  2421 
  2422 * isatool latex no longer depends on changed TEXINPUTS, instead
  2423 isatool document copies the Isabelle style files to the target
  2424 location;
  2425 
  2426 
  2427 *** Isar ***
  2428 
  2429 * Pure/Provers: improved proof by cases and induction;
  2430   - 'case' command admits impromptu naming of parameters (such as
  2431     "case (Suc n)");
  2432   - 'induct' method divinates rule instantiation from the inductive
  2433     claim; no longer requires excessive ?P bindings for proper
  2434     instantiation of cases;
  2435   - 'induct' method properly enumerates all possibilities of set/type
  2436     rules; as a consequence facts may be also passed through *type*
  2437     rules without further ado;
  2438   - 'induct' method now derives symbolic cases from the *rulified*
  2439     rule (before it used to rulify cases stemming from the internal
  2440     atomized version); this means that the context of a non-atomic
  2441     statement becomes is included in the hypothesis, avoiding the
  2442     slightly cumbersome show "PROP ?case" form;
  2443   - 'induct' may now use elim-style induction rules without chaining
  2444     facts, using ``missing'' premises from the goal state; this allows
  2445     rules stemming from inductive sets to be applied in unstructured
  2446     scripts, while still benefitting from proper handling of non-atomic
  2447     statements; NB: major inductive premises need to be put first, all
  2448     the rest of the goal is passed through the induction;
  2449   - 'induct' proper support for mutual induction involving non-atomic
  2450     rule statements (uses the new concept of simultaneous goals, see
  2451     below);
  2452   - append all possible rule selections, but only use the first
  2453     success (no backtracking);
  2454   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  2455   - undeclared rule case names default to numbers 1, 2, 3, ...;
  2456   - added 'print_induct_rules' (covered by help item in recent Proof
  2457     General versions);
  2458   - moved induct/cases attributes to Pure, methods to Provers;
  2459   - generic method setup instantiated for FOL and HOL;
  2460 
  2461 * Pure: support multiple simultaneous goal statements, for example
  2462 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  2463 meta-level mechanism, this acts as if several individual goals had
  2464 been stated separately; in particular common proof methods need to be
  2465 repeated in order to cover all claims; note that a single elimination
  2466 step is *not* sufficient to establish the two conjunctions, so this
  2467 fails:
  2468 
  2469   assume "A & B" then have A and B ..   (*".." fails*)
  2470 
  2471 better use "obtain" in situations as above; alternative refer to
  2472 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  2473 
  2474 * Pure: proper integration with ``locales''; unlike the original
  2475 version by Florian Kammller, Isar locales package high-level proof
  2476 contexts rather than raw logical ones (e.g. we admit to include
  2477 attributes everywhere); operations on locales include merge and
  2478 rename; support for implicit arguments (``structures''); simultaneous
  2479 type-inference over imports and text; see also HOL/ex/Locales.thy for
  2480 some examples;
  2481 
  2482 * Pure: the following commands have been ``localized'', supporting a
  2483 target locale specification "(in name)": 'lemma', 'theorem',
  2484 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  2485 stored both within the locale and at the theory level (exported and
  2486 qualified by the locale name);
  2487 
  2488 * Pure: theory goals may now be specified in ``long'' form, with
  2489 ad-hoc contexts consisting of arbitrary locale elements. for example
  2490 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  2491 definitions may be given, too); the result is a meta-level rule with
  2492 the context elements being discharged in the obvious way;
  2493 
  2494 * Pure: new proof command 'using' allows to augment currently used
  2495 facts after a goal statement ('using' is syntactically analogous to
  2496 'apply', but acts on the goal's facts only); this allows chained facts
  2497 to be separated into parts given before and after a claim, as in
  2498 ``from a and b have C using d and e <proof>'';
  2499 
  2500 * Pure: renamed "antecedent" case to "rule_context";
  2501 
  2502 * Pure: new 'judgment' command records explicit information about the
  2503 object-logic embedding (used by several tools internally); no longer
  2504 use hard-wired "Trueprop";
  2505 
  2506 * Pure: added 'corollary' command;
  2507 
  2508 * Pure: fixed 'token_translation' command;
  2509 
  2510 * Pure: removed obsolete 'exported' attribute;
  2511 
  2512 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  2513 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  2514 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  2515 
  2516 * Pure: method 'atomize' presents local goal premises as object-level
  2517 statements (atomic meta-level propositions); setup controlled via
  2518 rewrite rules declarations of 'atomize' attribute; example
  2519 application: 'induct' method with proper rule statements in improper
  2520 proof *scripts*;
  2521 
  2522 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  2523 now consider the syntactic context of assumptions, giving a better
  2524 chance to get type-inference of the arguments right (this is
  2525 especially important for locales);
  2526 
  2527 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  2528 mode;
  2529 
  2530 * Pure/obtain: the formal conclusion "thesis", being marked as
  2531 ``internal'', may no longer be reference directly in the text;
  2532 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  2533 situations;
  2534 
  2535 * Pure: generic 'sym' attribute which declares a rule both as pure
  2536 'elim?' and for the 'symmetric' operation;
  2537 
  2538 * Pure: marginal comments ``--'' may now occur just anywhere in the
  2539 text; the fixed correlation with particular command syntax has been
  2540 discontinued;
  2541 
  2542 * Pure: new method 'rules' is particularly well-suited for proof
  2543 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  2544 but often produces more compact proof terms with less detours;
  2545 
  2546 * Pure/Provers/classical: simplified integration with pure rule
  2547 attributes and methods; the classical "intro?/elim?/dest?"
  2548 declarations coincide with the pure ones; the "rule" method no longer
  2549 includes classically swapped intros; "intro" and "elim" methods no
  2550 longer pick rules from the context; also got rid of ML declarations
  2551 AddXIs/AddXEs/AddXDs; all of this has some potential for
  2552 INCOMPATIBILITY;
  2553 
  2554 * Provers/classical: attribute 'swapped' produces classical inversions
  2555 of introduction rules;
  2556 
  2557 * Provers/simplifier: 'simplified' attribute may refer to explicit
  2558 rules instead of full simplifier context; 'iff' attribute handles
  2559 conditional rules;
  2560 
  2561 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  2562 
  2563 * HOL: 'recdef' now fails on unfinished automated proofs, use
  2564 "(permissive)" option to recover old behavior;
  2565 
  2566 * HOL: 'inductive' no longer features separate (collective) attributes
  2567 for 'intros' (was found too confusing);
  2568 
  2569 * HOL: properly declared induction rules less_induct and
  2570 wf_induct_rule;
  2571 
  2572 
  2573 *** HOL ***
  2574 
  2575 * HOL: moved over to sane numeral syntax; the new policy is as
  2576 follows:
  2577 
  2578   - 0 and 1 are polymorphic constants, which are defined on any
  2579   numeric type (nat, int, real etc.);
  2580 
  2581   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  2582   binary representation internally;
  2583 
  2584   - type nat has special constructor Suc, and generally prefers Suc 0
  2585   over 1::nat and Suc (Suc 0) over 2::nat;
  2586 
  2587 This change may cause significant problems of INCOMPATIBILITY; here
  2588 are some hints on converting existing sources:
  2589 
  2590   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  2591   entities, so expressions involving "-" (unary or binary minus) need
  2592   to be spaced properly;
  2593 
  2594   - existing occurrences of "1" may need to be constraint "1::nat" or
  2595   even replaced by Suc 0; similar for old "2";
  2596 
  2597   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  2598 
  2599   - remove all special provisions on numerals in proofs;
  2600 
  2601 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  2602 representation (depends on bin_arith_simps in the default context);
  2603 
  2604 * HOL: symbolic syntax for x^2 (numeral 2);
  2605 
  2606 * HOL: the class of all HOL types is now called "type" rather than
  2607 "term"; INCOMPATIBILITY, need to adapt references to this type class
  2608 in axclass/classes, instance/arities, and (usually rare) occurrences
  2609 in typings (of consts etc.); internally the class is called
  2610 "HOL.type", ML programs should refer to HOLogic.typeS;
  2611 
  2612 * HOL/record package improvements:
  2613   - new derived operations "fields" to build a partial record section,
  2614     "extend" to promote a fixed record to a record scheme, and
  2615     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  2616     declared as simp by default;
  2617   - shared operations ("more", "fields", etc.) now need to be always
  2618     qualified) --- potential INCOMPATIBILITY;
  2619   - removed "make_scheme" operations (use "make" with "extend") --
  2620     INCOMPATIBILITY;
  2621   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  2622   - provides cases/induct rules for use with corresponding Isar
  2623     methods (for concrete records, record schemes, concrete more
  2624     parts, and schematic more parts -- in that order);
  2625   - internal definitions directly based on a light-weight abstract
  2626     theory of product types over typedef rather than datatype;
  2627 
  2628 * HOL: generic code generator for generating executable ML code from
  2629 specifications; specific support for HOL constructs such as inductive
  2630 datatypes and sets, as well as recursive functions; can be invoked
  2631 via 'generate_code' theory section;
  2632 
  2633 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  2634 
  2635 * HOL: consolidated and renamed several theories.  In particular:
  2636         Ord.thy has been absorbed into HOL.thy
  2637         String.thy has been absorbed into List.thy
  2638 
  2639 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  2640 (beware of argument permutation!);
  2641 
  2642 * HOL: linorder_less_split superseded by linorder_cases;
  2643 
  2644 * HOL/List: "nodups" renamed to "distinct";
  2645 
  2646 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  2647 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  2648   - Ex_def has changed, now need to use some_eq_ex
  2649 
  2650 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  2651 in this (rare) case use:
  2652 
  2653   delSWrapper "split_all_tac"
  2654   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  2655 
  2656 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  2657 MAY FAIL;
  2658 
  2659 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  2660 Isabelle's type classes, ^ on functions and relations has too general
  2661 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  2662 necessary to attach explicit type constraints;
  2663 
  2664 * HOL/Relation: the prefix name of the infix "O" has been changed from
  2665 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  2666 renamed accordingly (eg "compI" -> "rel_compI").
  2667 
  2668 * HOL: syntax translations now work properly with numerals and records
  2669 expressions;
  2670 
  2671 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  2672 of "lam" -- INCOMPATIBILITY;
  2673 
  2674 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  2675 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  2676 renamed "Product_Type.unit";
  2677 
  2678 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  2679 
  2680 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  2681 the "cases" method);
  2682 
  2683 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  2684 Florian Kammller);
  2685 
  2686 * HOL/IMP: updated and converted to new-style theory format; several
  2687 parts turned into readable document, with proper Isar proof texts and
  2688 some explanations (by Gerwin Klein);
  2689 
  2690 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  2691 
  2692 * HOL-Hyperreal is now a logic image;
  2693 
  2694 
  2695 *** HOLCF ***
  2696 
  2697 * Isar: consts/constdefs supports mixfix syntax for continuous
  2698 operations;
  2699 
  2700 * Isar: domain package adapted to new-style theory format, e.g. see
  2701 HOLCF/ex/Dnat.thy;
  2702 
  2703 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  2704 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  2705 lift.induct_tac, always use UU instead of Undef;
  2706 
  2707 * HOLCF/IMP: updated and converted to new-style theory;
  2708 
  2709 
  2710 *** ZF ***
  2711 
  2712 * Isar: proper integration of logic-specific tools and packages,
  2713 including theory commands '(co)inductive', '(co)datatype',
  2714 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  2715 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  2716 
  2717 * theory Main no longer includes AC; for the Axiom of Choice, base
  2718 your theory on Main_ZFC;
  2719 
  2720 * the integer library now covers quotients and remainders, with many
  2721 laws relating division to addition, multiplication, etc.;
  2722 
  2723 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  2724 typeless version of the formalism;
  2725 
  2726 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  2727 format;
  2728 
  2729 * ZF/Induct: new directory for examples of inductive definitions,
  2730 including theory Multiset for multiset orderings; converted to
  2731 new-style theory format;
  2732 
  2733 * ZF: many new theorems about lists, ordinals, etc.;
  2734 
  2735 
  2736 *** General ***
  2737 
  2738 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  2739 variable proof controls level of detail: 0 = no proofs (only oracle
  2740 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  2741 also ref manual for further ML interfaces;
  2742 
  2743 * Pure/axclass: removed obsolete ML interface
  2744 goal_subclass/goal_arity;
  2745 
  2746 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  2747 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  2748 separate tokens, so expressions involving minus need to be spaced
  2749 properly;
  2750 
  2751 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  2752 rather than "infixl" or "infixr";
  2753 
  2754 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  2755 sort constraint specifications in type inference; e.g. "x::_::foo"
  2756 ensures that the type of "x" is of sort "foo" (but not necessarily a
  2757 type variable);
  2758 
  2759 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  2760 control output of nested => (types); the default behavior is
  2761 "type_brackets";
  2762 
  2763 * Pure/syntax: builtin parse translation for "_constify" turns valued
  2764 tokens into AST constants;
  2765 
  2766 * Pure/syntax: prefer later declarations of translations and print
  2767 translation functions; potential INCOMPATIBILITY: need to reverse
  2768 multiple declarations for same syntax element constant;
  2769 
  2770 * Pure/show_hyps reset by default (in accordance to existing Isar
  2771 practice);
  2772 
  2773 * Provers/classical: renamed addaltern to addafter, addSaltern to
  2774 addSafter;
  2775 
  2776 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  2777 as well;
  2778 
  2779 * system: tested support for MacOS X; should be able to get Isabelle +
  2780 Proof General to work in a plain Terminal after installing Poly/ML
  2781 (e.g. from the Isabelle distribution area) and GNU bash alone
  2782 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  2783 support requires further installations, e.g. from
  2784 http://fink.sourceforge.net/);
  2785 
  2786 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  2787 
  2788 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  2789 of 40 MB), cf. ML_OPTIONS;
  2790 
  2791 * system: Proof General keywords specification is now part of the
  2792 Isabelle distribution (see etc/isar-keywords.el);
  2793 
  2794 * system: support for persistent Proof General sessions (refrain from
  2795 outdating all loaded theories on startup); user may create writable
  2796 logic images like this: ``isabelle -q HOL Test'';
  2797 
  2798 * system: smart selection of Isabelle process versus Isabelle
  2799 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  2800 run both "isabelle" and "Isabelle" even if file names are badly
  2801 damaged (executable inspects the case of the first letter of its own
  2802 name); added separate "isabelle-process" and "isabelle-interface";
  2803 
  2804 * system: refrain from any attempt at filtering input streams; no
  2805 longer support ``8bit'' encoding of old isabelle font, instead proper
  2806 iso-latin characters may now be used; the related isatools
  2807 "symbolinput" and "nonascii" have disappeared as well;
  2808 
  2809 * system: removed old "xterm" interface (the print modes "xterm" and
  2810 "xterm_color" are still available for direct use in a suitable
  2811 terminal);
  2812 
  2813 
  2814 
  2815 New in Isabelle99-2 (February 2001)
  2816 -----------------------------------
  2817 
  2818 *** Overview of INCOMPATIBILITIES ***
  2819 
  2820 * HOL: please note that theories in the Library and elsewhere often use the
  2821 new-style (Isar) format; to refer to their theorems in an ML script you must
  2822 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  2823 
  2824 * HOL: inductive package no longer splits induction rule aggressively,
  2825 but only as far as specified by the introductions given; the old
  2826 format may be recovered via ML function complete_split_rule or attribute
  2827 'split_rule (complete)';
  2828 
  2829 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  2830 gfp_Tarski to gfp_unfold;
  2831 
  2832 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  2833 
  2834 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  2835 relation); infix "^^" has been renamed "``"; infix "``" has been
  2836 renamed "`"; "univalent" has been renamed "single_valued";
  2837 
  2838 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  2839 operation;
  2840 
  2841 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  2842 
  2843 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  2844 
  2845 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  2846 consequence, it is no longer monotonic wrt. the local goal context
  2847 (which is now passed through the inductive cases);
  2848 
  2849 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  2850 \<gg> to \<ggreater>;
  2851 
  2852 
  2853 *** Document preparation ***
  2854 
  2855 * \isabellestyle{NAME} selects version of Isabelle output (currently
  2856 available: are "it" for near math-mode best-style output, "sl" for
  2857 slanted text style, and "tt" for plain type-writer; if no
  2858 \isabellestyle command is given, output is according to slanted
  2859 type-writer);
  2860 
  2861 * support sub/super scripts (for single symbols only), input syntax is
  2862 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  2863 
  2864 * some more standard symbols; see Appendix A of the system manual for
  2865 the complete list of symbols defined in isabellesym.sty;
  2866 
  2867 * improved isabelle style files; more abstract symbol implementation
  2868 (should now use \isamath{...} and \isatext{...} in custom symbol
  2869 definitions);
  2870 
  2871 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  2872 state; Note that presentation of goal states does not conform to
  2873 actual human-readable proof documents.  Please do not include goal
  2874 states into document output unless you really know what you are doing!
  2875 
  2876 * proper indentation of antiquoted output with proportional LaTeX
  2877 fonts;
  2878 
  2879 * no_document ML operator temporarily disables LaTeX document
  2880 generation;
  2881 
  2882 * isatool unsymbolize tunes sources for plain ASCII communication;
  2883 
  2884 
  2885 *** Isar ***
  2886 
  2887 * Pure: Isar now suffers initial goal statements to contain unbound
  2888 schematic variables (this does not conform to actual readable proof
  2889 documents, due to unpredictable outcome and non-compositional proof
  2890 checking); users who know what they are doing may use schematic goals
  2891 for Prolog-style synthesis of proven results;
  2892 
  2893 * Pure: assumption method (an implicit finishing) now handles actual
  2894 rules as well;
  2895 
  2896 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  2897 initial goal, declare "that" only as Pure intro (only for single
  2898 steps); the "that" rule assumption may now be involved in implicit
  2899 finishing, thus ".." becomes a feasible for trivial obtains;
  2900 
  2901 * Pure: default proof step now includes 'intro_classes'; thus trivial
  2902 instance proofs may be performed by "..";
  2903 
  2904 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  2905 statements as well;
  2906 
  2907 * Pure: more robust selection of calculational rules;
  2908 
  2909 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  2910 rule (as well as the assumption rule);
  2911 
  2912 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  2913 lemmas, using the graph browser tool;
  2914 
  2915 * Pure: predict failure of "show" in interactive mode;
  2916 
  2917 * Pure: 'thms_containing' now takes actual terms as arguments;
  2918 
  2919 * HOL: improved method 'induct' --- now handles non-atomic goals
  2920 (potential INCOMPATIBILITY); tuned error handling;
  2921 
  2922 * HOL: cases and induct rules now provide explicit hints about the
  2923 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  2924 any remaining facts are inserted into the goal verbatim;
  2925 
  2926 * HOL: local contexts (aka cases) may now contain term bindings as
  2927 well; the 'cases' and 'induct' methods new provide a ?case binding for
  2928 the result to be shown in each case;
  2929 
  2930 * HOL: added 'recdef_tc' command;
  2931 
  2932 * isatool convert assists in eliminating legacy ML scripts;
  2933 
  2934 
  2935 *** HOL ***
  2936 
  2937 * HOL/Library: a collection of generic theories to be used together
  2938 with main HOL; the theory loader path already includes this directory
  2939 by default; the following existing theories have been moved here:
  2940 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  2941 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  2942 
  2943 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  2944 modelling and verification task performed in Isabelle/HOL +
  2945 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  2946 
  2947 * HOL/Algebra: special summation operator SUM no longer exists, it has
  2948 been replaced by setsum; infix 'assoc' now has priority 50 (like
  2949 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  2950 'domain', this makes the theory consistent with mathematical
  2951 literature;
  2952 
  2953 * HOL basics: added overloaded operations "inverse" and "divide"
  2954 (infix "/"), syntax for generic "abs" operation, generic summation
  2955 operator \<Sum>;
  2956 
  2957 * HOL/typedef: simplified package, provide more useful rules (see also
  2958 HOL/subset.thy);
  2959 
  2960 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  2961 now expressed as a proper nested rule (old-style tactic scripts may
  2962 require atomize_strip_tac to cope with non-atomic premises);
  2963 
  2964 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  2965 to "split_conv" (old name still available for compatibility);
  2966 
  2967 * HOL: improved concrete syntax for strings (e.g. allows translation
  2968 rules with string literals);
  2969 
  2970 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  2971  and Fleuriot's mechanization of analysis, including the transcendental
  2972  functions for the reals;
  2973 
  2974 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  2975 
  2976 
  2977 *** CTT ***
  2978 
  2979 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  2980 "lam" is displayed as TWO lambda-symbols
  2981 
  2982 * CTT: theory Main now available, containing everything (that is, Bool
  2983 and Arith);
  2984 
  2985 
  2986 *** General ***
  2987 
  2988 * Pure: the Simplifier has been implemented properly as a derived rule
  2989 outside of the actual kernel (at last!); the overall performance
  2990 penalty in practical applications is about 50%, while reliability of
  2991 the Isabelle inference kernel has been greatly improved;
  2992 
  2993 * print modes "brackets" and "no_brackets" control output of nested =>
  2994 (types) and ==> (props); the default behaviour is "brackets";
  2995 
  2996 * Provers: fast_tac (and friends) now handle actual object-logic rules
  2997 as assumptions as well;
  2998 
  2999 * system: support Poly/ML 4.0;
  3000 
  3001 * system: isatool install handles KDE version 1 or 2;
  3002 
  3003 
  3004 
  3005 New in Isabelle99-1 (October 2000)
  3006 ----------------------------------
  3007 
  3008 *** Overview of INCOMPATIBILITIES ***
  3009 
  3010 * HOL: simplification of natural numbers is much changed; to partly
  3011 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  3012 issue the following ML commands:
  3013 
  3014   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  3015   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  3016 
  3017 * HOL: simplification no longer dives into case-expressions; this is
  3018 controlled by "t.weak_case_cong" for each datatype t;
  3019 
  3020 * HOL: nat_less_induct renamed to less_induct;
  3021 
  3022 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  3023 fixsome to patch .thy and .ML sources automatically;
  3024 
  3025   select_equality  -> some_equality
  3026   select_eq_Ex     -> some_eq_ex
  3027   selectI2EX       -> someI2_ex
  3028   selectI2         -> someI2
  3029   selectI          -> someI
  3030   select1_equality -> some1_equality
  3031   Eps_sym_eq       -> some_sym_eq_trivial
  3032   Eps_eq           -> some_eq_trivial
  3033 
  3034 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  3035 
  3036 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  3037 instead);
  3038 
  3039 * HOL: the recursion equations generated by 'recdef' are now called
  3040 f.simps instead of f.rules;
  3041 
  3042 * HOL: qed_spec_mp now also handles bounded ALL as well;
  3043 
  3044 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  3045 sometimes be needed;
  3046 
  3047 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  3048 
  3049 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  3050 
  3051 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  3052 product is now "<*>" instead of "Times"; the lexicographic product is
  3053 now "<*lex*>" instead of "**";
  3054 
  3055 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  3056 of main HOL, but was unused); better use HOL's datatype package;
  3057 
  3058 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  3059 the old syntax may be recovered as follows:
  3060 
  3061   syntax (symbols)
  3062     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  3063       (infixl "\\<oplus>" 100)
  3064 
  3065 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3066 
  3067 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  3068 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  3069 internally;
  3070 
  3071 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  3072 changed from A/r to A//r;
  3073 
  3074 * ZF: new treatment of arithmetic (nat & int) may break some old
  3075 proofs;
  3076 
  3077 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  3078 rulify -> rule_format, elimify -> elim_format, ...);
  3079 
  3080 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3081 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  3082 should have to change intro!! to intro? only); replaced "delrule" by
  3083 "rule del";
  3084 
  3085 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  3086 
  3087 * Provers: strengthened force_tac by using new first_best_tac;
  3088 
  3089 * LaTeX document preparation: several changes of isabelle.sty (see
  3090 lib/texinputs);
  3091 
  3092 
  3093 *** Document preparation ***
  3094 
  3095 * formal comments (text blocks etc.) in new-style theories may now
  3096 contain antiquotations of thm/prop/term/typ/text to be presented
  3097 according to latex print mode; concrete syntax is like this:
  3098 @{term[show_types] "f(x) = a + x"};
  3099 
  3100 * isatool mkdir provides easy setup of Isabelle session directories,
  3101 including proper document sources;
  3102 
  3103 * generated LaTeX sources are now deleted after successful run
  3104 (isatool document -c); may retain a copy somewhere else via -D option
  3105 of isatool usedir;
  3106 
  3107 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  3108 style files, achieving self-contained LaTeX sources and simplifying
  3109 LaTeX debugging;
  3110 
  3111 * old-style theories now produce (crude) LaTeX output as well;
  3112 
  3113 * browser info session directories are now self-contained (may be put
  3114 on WWW server seperately); improved graphs of nested sessions; removed
  3115 graph for 'all sessions';
  3116 
  3117 * several improvements in isabelle style files; \isabellestyle{it}
  3118 produces fake math mode output; \isamarkupheader is now \section by
  3119 default; see lib/texinputs/isabelle.sty etc.;
  3120 
  3121 
  3122 *** Isar ***
  3123 
  3124 * Isar/Pure: local results and corresponding term bindings are now
  3125 subject to Hindley-Milner polymorphism (similar to ML); this
  3126 accommodates incremental type-inference very nicely;
  3127 
  3128 * Isar/Pure: new derived language element 'obtain' supports
  3129 generalized existence reasoning;
  3130 
  3131 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  3132 support accumulation of results, without applying any rules yet;
  3133 useful to collect intermediate results without explicit name
  3134 references, and for use with transitivity rules with more than 2
  3135 premises;
  3136 
  3137 * Isar/Pure: scalable support for case-analysis type proofs: new
  3138 'case' language element refers to local contexts symbolically, as
  3139 produced by certain proof methods; internally, case names are attached
  3140 to theorems as "tags";
  3141 
  3142 * Isar/Pure: theory command 'hide' removes declarations from
  3143 class/type/const name spaces;
  3144 
  3145 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  3146 indicate potential overloading;
  3147 
  3148 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  3149 
  3150 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  3151 "{a,b,c}" instead of {a,b,c};
  3152 
  3153 * Isar/Pure now provides its own version of intro/elim/dest
  3154 attributes; useful for building new logics, but beware of confusion
  3155 with the version in Provers/classical;
  3156 
  3157 * Isar/Pure: the local context of (non-atomic) goals is provided via
  3158 case name 'antecedent';
  3159 
  3160 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  3161 to the current context is now done automatically);
  3162 
  3163 * Isar/Pure: theory command 'method_setup' provides a simple interface
  3164 for definining proof methods in ML;
  3165 
  3166 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3167 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  3168 most cases, one should have to change intro!! to intro? only);
  3169 replaced "delrule" by "rule del";
  3170 
  3171 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  3172 'symmetric' attribute (the latter supercedes [RS sym]);
  3173 
  3174 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  3175 method modifier); 'simp' method: 'only:' modifier removes loopers as
  3176 well (including splits);
  3177 
  3178 * Isar/Provers: Simplifier and Classical methods now support all kind
  3179 of modifiers used in the past, including 'cong', 'iff', etc.
  3180 
  3181 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  3182 of Simplifier and Classical reasoner);
  3183 
  3184 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  3185 now support named cases; major packages (inductive, datatype, primrec,
  3186 recdef) support case names and properly name parameters;
  3187 
  3188 * Isar/HOL: new transitivity rules for substitution in inequalities --
  3189 monotonicity conditions are extracted to be proven at end of
  3190 calculations;
  3191 
  3192 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  3193 method anyway;
  3194 
  3195 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  3196 split_if split_if_asm; datatype package provides theorems foo.splits =
  3197 foo.split foo.split_asm for each datatype;
  3198 
  3199 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  3200 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  3201 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  3202 use "(cases (simplified))" method in proper proof texts);
  3203 
  3204 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  3205 
  3206 * Isar: names of theorems etc. may be natural numbers as well;
  3207 
  3208 * Isar: 'pr' command: optional arguments for goals_limit and
  3209 ProofContext.prems_limit; no longer prints theory contexts, but only
  3210 proof states;
  3211 
  3212 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  3213 additional print modes to be specified; e.g. "pr(latex)" will print
  3214 proof state according to the Isabelle LaTeX style;
  3215 
  3216 * Isar: improved support for emulating tactic scripts, including proof
  3217 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  3218 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  3219 (for HOL datatypes);
  3220 
  3221 * Isar: simplified (more robust) goal selection of proof methods: 1st
  3222 goal, all goals, or explicit goal specifier (tactic emulation); thus
  3223 'proof method scripts' have to be in depth-first order;
  3224 
  3225 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  3226 
  3227 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  3228 should instead use individual commands for printing items
  3229 (print_commands, print_methods etc.);
  3230 
  3231 * Isar: added 'nothing' --- the empty list of theorems;
  3232 
  3233 
  3234 *** HOL ***
  3235 
  3236 * HOL/MicroJava: formalization of a fragment of Java, together with a
  3237 corresponding virtual machine and a specification of its bytecode
  3238 verifier and a lightweight bytecode verifier, including proofs of
  3239 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  3240 Cornelia Pusch (see also the homepage of project Bali at
  3241 http://isabelle.in.tum.de/Bali/);
  3242 
  3243 * HOL/Algebra: new theory of rings and univariate polynomials, by
  3244 Clemens Ballarin;
  3245 
  3246 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  3247 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  3248 Rasmussen;
  3249 
  3250 * HOL/Lattice: fundamental concepts of lattice theory and order
  3251 structures, including duals, properties of bounds versus algebraic
  3252 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  3253 Theorem for complete lattices etc.; may also serve as a demonstration
  3254 for abstract algebraic reasoning using axiomatic type classes, and
  3255 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  3256 
  3257 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  3258 von Oheimb;
  3259 
  3260 * HOL/IMPP: extension of IMP with local variables and mutually
  3261 recursive procedures, by David von Oheimb;
  3262 
  3263 * HOL/Lambda: converted into new-style theory and document;
  3264 
  3265 * HOL/ex/Multiquote: example of multiple nested quotations and
  3266 anti-quotations -- basically a generalized version of de-Bruijn
  3267 representation; very useful in avoiding lifting of operations;
  3268 
  3269 * HOL/record: added general record equality rule to simpset; fixed
  3270 select-update simplification procedure to handle extended records as
  3271 well; admit "r" as field name;
  3272 
  3273 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  3274 other numeric types and also as the identity of groups, rings, etc.;
  3275 
  3276 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  3277 Types nat and int belong to this axclass;
  3278 
  3279 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  3280    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  3281    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  3282   two terms #m*u and #n*u are replaced by #(m+n)*u
  3283     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  3284   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  3285     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  3286 
  3287 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  3288 powerful prover for predicate logic but knows nothing of clasets; see
  3289 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  3290 
  3291 * HOL: new version of "case_tac" subsumes both boolean case split and
  3292 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  3293 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  3294 
  3295 * HOL: simplification no longer dives into case-expressions: only the
  3296 selector expression is simplified, but not the remaining arms; to
  3297 enable full simplification of case-expressions for datatype t, you may
  3298 remove t.weak_case_cong from the simpset, either globally (Delcongs
  3299 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  3300 
  3301 * HOL/recdef: the recursion equations generated by 'recdef' for
  3302 function 'f' are now called f.simps instead of f.rules; if all
  3303 termination conditions are proved automatically, these simplification
  3304 rules are added to the simpset, as in primrec; rules may be named
  3305 individually as well, resulting in a separate list of theorems for
  3306 each equation;
  3307 
  3308 * HOL/While is a new theory that provides a while-combinator. It
  3309 permits the definition of tail-recursive functions without the
  3310 provision of a termination measure. The latter is necessary once the
  3311 invariant proof rule for while is applied.
  3312 
  3313 * HOL: new (overloaded) notation for the set of elements below/above
  3314 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  3315 
  3316 * HOL: theorems impI, allI, ballI bound as "strip";
  3317 
  3318 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  3319 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  3320 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  3321 
  3322 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3323 
  3324 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  3325 main HOL, but was unused);
  3326 
  3327 * HOL: fewer consts declared as global (e.g. have to refer to
  3328 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  3329 
  3330 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  3331 in case of overlap with user translations (e.g. judgements over
  3332 tuples); (note that the underlying logical represenation is still
  3333 bogus);
  3334 
  3335 
  3336 *** ZF ***
  3337 
  3338 * ZF: simplification automatically cancels common terms in arithmetic
  3339 expressions over nat and int;
  3340 
  3341 * ZF: new treatment of nat to minimize type-checking: all operators
  3342 coerce their operands to a natural number using the function natify,
  3343 making the algebraic laws unconditional;
  3344 
  3345 * ZF: as above, for int: operators coerce their operands to an integer
  3346 using the function intify;
  3347 
  3348 * ZF: the integer library now contains many of the usual laws for the
  3349 orderings, including $<=, and monotonicity laws for $+ and $*;
  3350 
  3351 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  3352 simplification;
  3353 
  3354 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  3355 to the simplifier and classical reasoner simultaneously;
  3356 
  3357 
  3358 *** General ***
  3359 
  3360 * Provers: blast_tac now handles actual object-logic rules as
  3361 assumptions; note that auto_tac uses blast_tac internally as well;
  3362 
  3363 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  3364 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  3365 
  3366 * Provers: delrules now handles destruct rules as well (no longer need
  3367 explicit make_elim);
  3368 
  3369 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  3370   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3371 use instead the strong form,
  3372   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3373 in HOL, FOL and ZF the function cla_make_elim will create such rules
  3374 from destruct-rules;
  3375 
  3376 * Provers: Simplifier.easy_setup provides a fast path to basic
  3377 Simplifier setup for new object-logics;
  3378 
  3379 * Pure: AST translation rules no longer require constant head on LHS;
  3380 
  3381 * Pure: improved name spaces: ambiguous output is qualified; support
  3382 for hiding of names;
  3383 
  3384 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  3385 XSYMBOL_HOME; no longer need to do manual configuration in most
  3386 situations;
  3387 
  3388 * system: compression of ML heaps images may now be controlled via -c
  3389 option of isabelle and isatool usedir (currently only observed by
  3390 Poly/ML);
  3391 
  3392 * system: isatool installfonts may handle X-Symbol fonts as well (very
  3393 useful for remote X11);
  3394 
  3395 * system: provide TAGS file for Isabelle sources;
  3396 
  3397 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  3398 order;
  3399 
  3400 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  3401 timing flag supersedes proof_timing and Toplevel.trace;
  3402 
  3403 * ML: new combinators |>> and |>>> for incremental transformations
  3404 with secondary results (e.g. certain theory extensions):
  3405 
  3406 * ML: PureThy.add_defs gets additional argument to indicate potential
  3407 overloading (usually false);
  3408 
  3409 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  3410 results;
  3411 
  3412 
  3413 
  3414 New in Isabelle99 (October 1999)
  3415 --------------------------------
  3416 
  3417 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3418 
  3419 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  3420 are no longer simplified.  (This allows the simplifier to unfold recursive
  3421 functional programs.)  To restore the old behaviour, declare
  3422 
  3423     Delcongs [if_weak_cong];
  3424 
  3425 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  3426 complement;
  3427 
  3428 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  3429 
  3430 * HOL/datatype: mutual_induct_tac no longer exists --
  3431   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  3432 
  3433 * HOL/typedef: fixed type inference for representing set; type
  3434 arguments now have to occur explicitly on the rhs as type constraints;
  3435 
  3436 * ZF: The con_defs part of an inductive definition may no longer refer
  3437 to constants declared in the same theory;
  3438 
  3439 * HOL, ZF: the function mk_cases, generated by the inductive
  3440 definition package, has lost an argument.  To simplify its result, it
  3441 uses the default simpset instead of a supplied list of theorems.
  3442 
  3443 * HOL/List: the constructors of type list are now Nil and Cons;
  3444 
  3445 * Simplifier: the type of the infix ML functions
  3446         setSSolver addSSolver setSolver addSolver
  3447 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  3448 for packaging solvers. A solver is created via
  3449         mk_solver: string -> (thm list -> int -> tactic) -> solver
  3450 where the string argument is only a comment.
  3451 
  3452 
  3453 *** Proof tools ***
  3454 
  3455 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  3456 decision procedure for linear arithmetic. Currently it is used for
  3457 types `nat', `int', and `real' in HOL (see below); it can, should and
  3458 will be instantiated for other types and logics as well.
  3459 
  3460 * The simplifier now accepts rewrite rules with flexible heads, eg
  3461      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  3462   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  3463   matching.
  3464 
  3465 
  3466 *** General ***
  3467 
  3468 * New Isabelle/Isar subsystem provides an alternative to traditional
  3469 tactical theorem proving; together with the ProofGeneral/isar user
  3470 interface it offers an interactive environment for developing human
  3471 readable proof documents (Isar == Intelligible semi-automated
  3472 reasoning); for further information see isatool doc isar-ref,
  3473 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  3474 
  3475 * improved and simplified presentation of theories: better HTML markup
  3476 (including colors), graph views in several sizes; isatool usedir now
  3477 provides a proper interface for user theories (via -P option); actual
  3478 document preparation based on (PDF)LaTeX is available as well (for
  3479 new-style theories only); see isatool doc system for more information;
  3480 
  3481 * native support for Proof General, both for classic Isabelle and
  3482 Isabelle/Isar;
  3483 
  3484 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  3485 using the graph browser tool;
  3486 
  3487 * Isabelle manuals now also available as PDF;
  3488 
  3489 * theory loader rewritten from scratch (may not be fully
  3490 bug-compatible); old loadpath variable has been replaced by show_path,
  3491 add_path, del_path, reset_path functions; new operations such as
  3492 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  3493 isatool doc ref);
  3494 
  3495 * improved isatool install: option -k creates KDE application icon,
  3496 option -p DIR installs standalone binaries;
  3497 
  3498 * added ML_PLATFORM setting (useful for cross-platform installations);
  3499 more robust handling of platform specific ML images for SML/NJ;
  3500 
  3501 * the settings environment is now statically scoped, i.e. it is never
  3502 created again in sub-processes invoked from isabelle, isatool, or
  3503 Isabelle;
  3504 
  3505 * path element specification '~~' refers to '$ISABELLE_HOME';
  3506 
  3507 * in locales, the "assumes" and "defines" parts may be omitted if
  3508 empty;
  3509 
  3510 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  3511 long arrows);
  3512 
  3513 * new print_mode "HTML";
  3514 
  3515 * new flag show_tags controls display of tags of theorems (which are
  3516 basically just comments that may be attached by some tools);
  3517 
  3518 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  3519 mode and goal output format:
  3520 
  3521 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  3522 244c244
  3523 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  3524 ---
  3525 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  3526 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  3527 181c181
  3528 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  3529 ---
  3530 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  3531 
  3532 * function bind_thms stores lists of theorems (cf. bind_thm);
  3533 
  3534 * new shorthand tactics ftac, eatac, datac, fatac;
  3535 
  3536 * qed (and friends) now accept "" as result name; in that case the
  3537 theorem is not stored, but proper checks and presentation of the
  3538 result still apply;
  3539 
  3540 * theorem database now also indexes constants "Trueprop", "all",
  3541 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  3542 
  3543 
  3544 *** HOL ***
  3545 
  3546 ** HOL arithmetic **
  3547 
  3548 * There are now decision procedures for linear arithmetic over nat and
  3549 int:
  3550 
  3551 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  3552 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  3553 are treated as atomic; subformulae not involving type `nat' or `int'
  3554 are ignored; quantified subformulae are ignored unless they are
  3555 positive universal or negative existential. The tactic has to be
  3556 invoked by hand and can be a little bit slow. In particular, the
  3557 running time is exponential in the number of occurrences of `min' and
  3558 `max', and `-' on `nat'.
  3559 
  3560 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  3561 (negated) (in)equalities among the premises and the conclusion into
  3562 account (i.e. no compound formulae) and does not know about `min' and
  3563 `max', and `-' on `nat'. It is fast and is used automatically by the
  3564 simplifier.
  3565 
  3566 NB: At the moment, these decision procedures do not cope with mixed
  3567 nat/int formulae where the two parts interact, such as `m < n ==>
  3568 int(m) < int(n)'.
  3569 
  3570 * HOL/Numeral provides a generic theory of numerals (encoded
  3571 efficiently as bit strings); setup for types nat/int/real is in place;
  3572 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  3573 int, existing theories and proof scripts may require a few additional
  3574 type constraints;
  3575 
  3576 * integer division and remainder can now be performed on constant
  3577 arguments;
  3578 
  3579 * many properties of integer multiplication, division and remainder
  3580 are now available;
  3581 
  3582 * An interface to the Stanford Validity Checker (SVC) is available through the
  3583 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  3584 are proved automatically.  SVC must be installed separately, and its results
  3585 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  3586 invocation of the underlying oracle).  For SVC see
  3587   http://verify.stanford.edu/SVC
  3588 
  3589 * IsaMakefile: the HOL-Real target now builds an actual image;
  3590 
  3591 
  3592 ** HOL misc **
  3593 
  3594 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  3595 (in Isabelle/Isar) -- by Gertrud Bauer;
  3596 
  3597 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  3598 analysis for assembly languages with subtypes;
  3599 
  3600 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  3601 -- avoids syntactic ambiguities and treats state, transition, and
  3602 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  3603 changed syntax and (many) tactics;
  3604 
  3605 * HOL/inductive: Now also handles more general introduction rules such
  3606   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  3607   theorems are now maintained within the theory (maintained via the
  3608   "mono" attribute);
  3609 
  3610 * HOL/datatype: Now also handles arbitrarily branching datatypes
  3611   (using function types) such as
  3612 
  3613   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  3614 
  3615 * HOL/record: record_simproc (part of the default simpset) takes care
  3616 of selectors applied to updated records; record_split_tac is no longer
  3617 part of the default claset; update_defs may now be removed from the
  3618 simpset in many cases; COMPATIBILITY: old behavior achieved by
  3619 
  3620   claset_ref () := claset() addSWrapper record_split_wrapper;
  3621   Delsimprocs [record_simproc]
  3622 
  3623 * HOL/typedef: fixed type inference for representing set; type
  3624 arguments now have to occur explicitly on the rhs as type constraints;
  3625 
  3626 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  3627 names rather than an ML expression;
  3628 
  3629 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  3630 supplied later.  Program schemes can be defined, such as
  3631     "While B C s = (if B s then While B C (C s) else s)"
  3632 where the well-founded relation can be chosen after B and C have been given.
  3633 
  3634 * HOL/List: the constructors of type list are now Nil and Cons;
  3635 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  3636 course, ML tools referring to List.list.op # etc. have to be adapted;
  3637 
  3638 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  3639 disabled by default; run isabelle with option -m HOL to get back to
  3640 the original Gordon/HOL-style output;
  3641 
  3642 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  3643 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  3644 
  3645 * HOL basic syntax simplified (more orthogonal): all variants of
  3646 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  3647 Eps operator is provided as well: "SOME x. P[x]";
  3648 
  3649 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  3650 
  3651 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  3652 thus available for user theories;
  3653 
  3654 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  3655 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  3656 time;
  3657 
  3658 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  3659 several times and then mp;
  3660 
  3661 
  3662 *** LK ***
  3663 
  3664 * the notation <<...>> is now available as a notation for sequences of
  3665 formulas;
  3666 
  3667 * the simplifier is now installed
  3668 
  3669 * the axiom system has been generalized (thanks to Soren Heilmann)
  3670 
  3671 * the classical reasoner now has a default rule database
  3672 
  3673 
  3674 *** ZF ***
  3675 
  3676 * new primrec section allows primitive recursive functions to be given
  3677 directly (as in HOL) over datatypes and the natural numbers;
  3678 
  3679 * new tactics induct_tac and exhaust_tac for induction (or case
  3680 analysis) over datatypes and the natural numbers;
  3681 
  3682 * the datatype declaration of type T now defines the recursor T_rec;
  3683 
  3684 * simplification automatically does freeness reasoning for datatype
  3685 constructors;
  3686 
  3687 * automatic type-inference, with AddTCs command to insert new
  3688 type-checking rules;
  3689 
  3690 * datatype introduction rules are now added as Safe Introduction rules
  3691 to the claset;
  3692 
  3693 * the syntax "if P then x else y" is now available in addition to
  3694 if(P,x,y);
  3695 
  3696 
  3697 *** Internal programming interfaces ***
  3698 
  3699 * tuned simplifier trace output; new flag debug_simp;
  3700 
  3701 * structures Vartab / Termtab (instances of TableFun) offer efficient
  3702 tables indexed by indexname_ord / term_ord (compatible with aconv);
  3703 
  3704 * AxClass.axclass_tac lost the theory argument;
  3705 
  3706 * tuned current_goals_markers semantics: begin / end goal avoids
  3707 printing empty lines;
  3708 
  3709 * removed prs and prs_fn hook, which was broken because it did not
  3710 include \n in its semantics, forcing writeln to add one
  3711 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  3712 string -> unit if you really want to output text without newline;
  3713 
  3714 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  3715 plain output, interface builders may have to enable 'isabelle_font'
  3716 mode to get Isabelle font glyphs as before;
  3717 
  3718 * refined token_translation interface; INCOMPATIBILITY: output length
  3719 now of type real instead of int;
  3720 
  3721 * theory loader actions may be traced via new ThyInfo.add_hook
  3722 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  3723 your own database of information attached to *whole* theories -- as
  3724 opposed to intra-theory data slots offered via TheoryDataFun;
  3725 
  3726 * proper handling of dangling sort hypotheses (at last!);
  3727 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  3728 extra sort hypotheses that can be witnessed from the type signature;
  3729 the force_strip_shyps flag is gone, any remaining shyps are simply
  3730 left in the theorem (with a warning issued by strip_shyps_warning);
  3731 
  3732 
  3733 
  3734 New in Isabelle98-1 (October 1998)
  3735 ----------------------------------
  3736 
  3737 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3738 
  3739 * several changes of automated proof tools;
  3740 
  3741 * HOL: major changes to the inductive and datatype packages, including
  3742 some minor incompatibilities of theory syntax;
  3743 
  3744 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  3745 called `inj_on';
  3746 
  3747 * HOL: removed duplicate thms in Arith:
  3748   less_imp_add_less  should be replaced by  trans_less_add1
  3749   le_imp_add_le      should be replaced by  trans_le_add1
  3750 
  3751 * HOL: unary minus is now overloaded (new type constraints may be
  3752 required);
  3753 
  3754 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  3755 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  3756 now taken as an integer constant.
  3757 
  3758 * Pure: ML function 'theory_of' renamed to 'theory';
  3759 
  3760 
  3761 *** Proof tools ***
  3762 
  3763 * Simplifier:
  3764   1. Asm_full_simp_tac is now more aggressive.
  3765      1. It will sometimes reorient premises if that increases their power to
  3766         simplify.
  3767      2. It does no longer proceed strictly from left to right but may also
  3768         rotate premises to achieve further simplification.
  3769      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  3770      old Asm_full_simp_tac in that it does not rotate premises.
  3771   2. The simplifier now knows a little bit about nat-arithmetic.
  3772 
  3773 * Classical reasoner: wrapper mechanism for the classical reasoner now
  3774 allows for selected deletion of wrappers, by introduction of names for
  3775 wrapper functionals.  This implies that addbefore, addSbefore,
  3776 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  3777 and that adding two tactics with the same name overwrites the first
  3778 one (emitting a warning).
  3779   type wrapper = (int -> tactic) -> (int -> tactic)
  3780   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  3781   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  3782   delWrapper, delSWrapper: claset *  string            -> claset
  3783   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  3784 
  3785 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  3786 semantics; addbefore now affects only the unsafe part of step_tac
  3787 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  3788 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  3789 by Force_tac;
  3790 
  3791 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  3792 compWrapper; added safe wrapper (and access functions for it);
  3793 
  3794 * HOL/split_all_tac is now much faster and fails if there is nothing
  3795 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  3796 and the names of the automatically generated variables have changed.
  3797 split_all_tac has moved within claset() from unsafe wrappers to safe
  3798 wrappers, which means that !!-bound variables are split much more
  3799 aggressively, and safe_tac and clarify_tac now split such variables.
  3800 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  3801 Note: the same holds for record_split_tac, which does the job of
  3802 split_all_tac for record fields.
  3803 
  3804 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  3805 permanently to the default simpset using Addsplits just like
  3806 Addsimps. They can be removed via Delsplits just like
  3807 Delsimps. Lower-case versions are also available.
  3808 
  3809 * HOL/Simplifier: The rule split_if is now part of the default
  3810 simpset. This means that the simplifier will eliminate all occurrences
  3811 of if-then-else in the conclusion of a goal. To prevent this, you can
  3812 either remove split_if completely from the default simpset by
  3813 `Delsplits [split_if]' or remove it in a specific call of the
  3814 simplifier using `... delsplits [split_if]'.  You can also add/delete
  3815 other case splitting rules to/from the default simpset: every datatype
  3816 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  3817 t is the name of the datatype).
  3818 
  3819 * Classical reasoner / Simplifier combination: new force_tac (and
  3820 derivatives Force_tac, force) combines rewriting and classical
  3821 reasoning (and whatever other tools) similarly to auto_tac, but is
  3822 aimed to solve the given subgoal completely.
  3823 
  3824 
  3825 *** General ***
  3826 
  3827 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  3828 and `goalw': the theory is no longer needed as an explicit argument -
  3829 the current theory context is used; assumptions are no longer returned
  3830 at the ML-level unless one of them starts with ==> or !!; it is
  3831 recommended to convert to these new commands using isatool fixgoal
  3832 (backup your sources first!);
  3833 
  3834 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  3835 the current theory context, and 'theory' to lookup stored theories;
  3836 
  3837 * new theory section 'locale' for declaring constants, assumptions and
  3838 definitions that have local scope;
  3839 
  3840 * new theory section 'nonterminals' for purely syntactic types;
  3841 
  3842 * new theory section 'setup' for generic ML setup functions
  3843 (e.g. package initialization);
  3844 
  3845 * the distribution now includes Isabelle icons: see
  3846 lib/logo/isabelle-{small,tiny}.xpm;
  3847 
  3848 * isatool install - install binaries with absolute references to
  3849 ISABELLE_HOME/bin;
  3850 
  3851 * isatool logo -- create instances of the Isabelle logo (as EPS);
  3852 
  3853 * print mode 'emacs' reserved for Isamode;
  3854 
  3855 * support multiple print (ast) translations per constant name;
  3856 
  3857 * theorems involving oracles are now printed with a suffixed [!];
  3858 
  3859 
  3860 *** HOL ***
  3861 
  3862 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  3863 
  3864 * HOL/inductive package reorganized and improved: now supports mutual
  3865 definitions such as
  3866 
  3867   inductive EVEN ODD
  3868     intrs
  3869       null "0 : EVEN"
  3870       oddI "n : EVEN ==> Suc n : ODD"
  3871       evenI "n : ODD ==> Suc n : EVEN"
  3872 
  3873 new theorem list "elims" contains an elimination rule for each of the
  3874 recursive sets; inductive definitions now handle disjunctive premises
  3875 correctly (also ZF);
  3876 
  3877 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  3878 "mutual_induct" no longer exists - the induction rule is always
  3879 contained in "induct";
  3880 
  3881 
  3882 * HOL/datatype package re-implemented and greatly improved: now
  3883 supports mutually recursive datatypes such as
  3884 
  3885   datatype
  3886     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  3887             | SUM ('a aexp) ('a aexp)
  3888             | DIFF ('a aexp) ('a aexp)
  3889             | NUM 'a
  3890   and
  3891     'a bexp = LESS ('a aexp) ('a aexp)
  3892             | AND ('a bexp) ('a bexp)
  3893             | OR ('a bexp) ('a bexp)
  3894 
  3895 as well as indirectly recursive datatypes such as
  3896 
  3897   datatype
  3898     ('a, 'b) term = Var 'a
  3899                   | App 'b ((('a, 'b) term) list)
  3900 
  3901 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  3902 induction on mutually / indirectly recursive datatypes.
  3903 
  3904 Primrec equations are now stored in theory and can be accessed via
  3905 <function_name>.simps.
  3906 
  3907 INCOMPATIBILITIES:
  3908 
  3909   - Theories using datatypes must now have theory Datatype as an
  3910     ancestor.
  3911   - The specific <typename>.induct_tac no longer exists - use the
  3912     generic induct_tac instead.
  3913   - natE has been renamed to nat.exhaust - use exhaust_tac
  3914     instead of res_inst_tac ... natE. Note that the variable
  3915     names in nat.exhaust differ from the names in natE, this
  3916     may cause some "fragile" proofs to fail.
  3917   - The theorems split_<typename>_case and split_<typename>_case_asm
  3918     have been renamed to <typename>.split and <typename>.split_asm.
  3919   - Since default sorts of type variables are now handled correctly,
  3920     some datatype definitions may have to be annotated with explicit
  3921     sort constraints.
  3922   - Primrec definitions no longer require function name and type
  3923     of recursive argument.
  3924 
  3925 Consider using isatool fixdatatype to adapt your theories and proof
  3926 scripts to the new package (backup your sources first!).
  3927 
  3928 
  3929 * HOL/record package: considerably improved implementation; now
  3930 includes concrete syntax for record types, terms, updates; theorems
  3931 for surjective pairing and splitting !!-bound record variables; proof
  3932 support is as follows:
  3933 
  3934   1) standard conversions (selectors or updates applied to record
  3935 constructor terms) are part of the standard simpset;
  3936 
  3937   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  3938 made part of standard simpset and claset via addIffs;
  3939 
  3940   3) a tactic for record field splitting (record_split_tac) is part of
  3941 the standard claset (addSWrapper);
  3942 
  3943 To get a better idea about these rules you may retrieve them via
  3944 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  3945 the name of your record type.
  3946 
  3947 The split tactic 3) conceptually simplifies by the following rule:
  3948 
  3949   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  3950 
  3951 Thus any record variable that is bound by meta-all will automatically
  3952 blow up into some record constructor term, consequently the
  3953 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  3954 solve record problems automatically.
  3955 
  3956 
  3957 * reorganized the main HOL image: HOL/Integ and String loaded by
  3958 default; theory Main includes everything;
  3959 
  3960 * automatic simplification of integer sums and comparisons, using cancellation;
  3961 
  3962 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  3963 
  3964 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  3965 
  3966 * many new identities for unions, intersections, set difference, etc.;
  3967 
  3968 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  3969 called split_if, split_split, split_sum_case and split_nat_case (to go
  3970 with add/delsplits);
  3971 
  3972 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  3973 (?x::unit) = (); this is made part of the default simpset, which COULD
  3974 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  3975 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  3976 unit_abs_eta_conv is added in order to counter the effect of
  3977 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  3978 %u.f();
  3979 
  3980 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  3981 makes more sense);
  3982 
  3983 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  3984   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  3985   disjointness reasoning but breaking a few old proofs.
  3986 
  3987 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  3988 to 'converse' from 'inverse' (for compatibility with ZF and some
  3989 literature);
  3990 
  3991 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  3992 the well-founded relation;
  3993 
  3994 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  3995     Compl A.  The "Compl" syntax remains available as input syntax for this
  3996     release ONLY.
  3997 
  3998 * HOL/Update: new theory of function updates:
  3999     f(a:=b) == %x. if x=a then b else f x
  4000 may also be iterated as in f(a:=b,c:=d,...);
  4001 
  4002 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  4003 
  4004 * HOL/List:
  4005   - new function list_update written xs[i:=v] that updates the i-th
  4006     list position. May also be iterated as in xs[i:=a,j:=b,...].
  4007   - new function `upt' written [i..j(] which generates the list
  4008     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  4009     bound write [i..j], which is a shorthand for [i..j+1(].
  4010   - new lexicographic orderings and corresponding wellfoundedness theorems.
  4011 
  4012 * HOL/Arith:
  4013   - removed 'pred' (predecessor) function;
  4014   - generalized some theorems about n-1;
  4015   - many new laws about "div" and "mod";
  4016   - new laws about greatest common divisors (see theory ex/Primes);
  4017 
  4018 * HOL/Relation: renamed the relational operator r^-1 "converse"
  4019 instead of "inverse";
  4020 
  4021 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  4022   of the multiset ordering;
  4023 
  4024 * directory HOL/Real: a construction of the reals using Dedekind cuts
  4025   (not included by default);
  4026 
  4027 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  4028 
  4029 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  4030   programs, i.e. different program variables may have different types.
  4031 
  4032 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4033   [previously, this check worked only if the rewrite rule was unconditional]
  4034   Now rew can involve either definitions or equalities (either == or =).
  4035 
  4036 
  4037 *** ZF ***
  4038 
  4039 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  4040   only the theorems proved on ZF.ML;
  4041 
  4042 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4043   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4044   disjointness reasoning but breaking a few old proofs.
  4045 
  4046 * ZF/Update: new theory of function updates
  4047     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  4048   may also be iterated as in f(a:=b,c:=d,...);
  4049 
  4050 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  4051 
  4052 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4053   [previously, this check worked only if the rewrite rule was unconditional]
  4054   Now rew can involve either definitions or equalities (either == or =).
  4055 
  4056 * case_tac provided for compatibility with HOL
  4057     (like the old excluded_middle_tac, but with subgoals swapped)
  4058 
  4059 
  4060 *** Internal programming interfaces ***
  4061 
  4062 * Pure: several new basic modules made available for general use, see
  4063 also src/Pure/README;
  4064 
  4065 * improved the theory data mechanism to support encapsulation (data
  4066 kind name replaced by private Object.kind, acting as authorization
  4067 key); new type-safe user interface via functor TheoryDataFun; generic
  4068 print_data function becomes basically useless;
  4069 
  4070 * removed global_names compatibility flag -- all theory declarations
  4071 are qualified by default;
  4072 
  4073 * module Pure/Syntax now offers quote / antiquote translation
  4074 functions (useful for Hoare logic etc. with implicit dependencies);
  4075 see HOL/ex/Antiquote for an example use;
  4076 
  4077 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  4078 cterm -> thm;
  4079 
  4080 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  4081 subgoal;
  4082 
  4083 * Display.print_goals function moved to Locale.print_goals;
  4084 
  4085 * standard print function for goals supports current_goals_markers
  4086 variable for marking begin of proof, end of proof, start of goal; the
  4087 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  4088 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  4089 for example;
  4090 
  4091 
  4092 
  4093 New in Isabelle98 (January 1998)
  4094 --------------------------------
  4095 
  4096 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4097 
  4098 * changed lexical syntax of terms / types: dots made part of long
  4099 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  4100 
  4101 * simpset (and claset) reference variable replaced by functions
  4102 simpset / simpset_ref;
  4103 
  4104 * no longer supports theory aliases (via merge) and non-trivial
  4105 implicit merge of thms' signatures;
  4106 
  4107 * most internal names of constants changed due to qualified names;
  4108 
  4109 * changed Pure/Sequence interface (see Pure/seq.ML);
  4110 
  4111 
  4112 *** General Changes ***
  4113 
  4114 * hierachically structured name spaces (for consts, types, axms, thms
  4115 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  4116 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  4117 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  4118 long_names for fully qualified output names; NOTE: ML programs
  4119 (special tactics, packages etc.) referring to internal names may have
  4120 to be adapted to cope with fully qualified names; in case of severe
  4121 backward campatibility problems try setting 'global_names' at compile
  4122 time to have enrything declared within a flat name space; one may also
  4123 fine tune name declarations in theories via the 'global' and 'local'
  4124 section;
  4125 
  4126 * reimplemented the implicit simpset and claset using the new anytype
  4127 data filed in signatures; references simpset:simpset ref etc. are
  4128 replaced by functions simpset:unit->simpset and
  4129 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  4130 to patch your ML files accordingly;
  4131 
  4132 * HTML output now includes theory graph data for display with Java
  4133 applet or isatool browser; data generated automatically via isatool
  4134 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  4135 
  4136 * defs may now be conditional; improved rewrite_goals_tac to handle
  4137 conditional equations;
  4138 
  4139 * defs now admits additional type arguments, using TYPE('a) syntax;
  4140 
  4141 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  4142 creates a new theory node; implicit merge of thms' signatures is
  4143 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  4144 transfer:theory->thm->thm in (rare) cases;
  4145 
  4146 * improved handling of draft signatures / theories; draft thms (and
  4147 ctyps, cterms) are automatically promoted to real ones;
  4148 
  4149 * slightly changed interfaces for oracles: admit many per theory, named
  4150 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  4151 
  4152 * print_goals: optional output of const types (set show_consts and
  4153 show_types);
  4154 
  4155 * improved output of warnings (###) and errors (***);
  4156 
  4157 * subgoal_tac displays a warning if the new subgoal has type variables;
  4158 
  4159 * removed old README and Makefiles;
  4160 
  4161 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  4162 
  4163 * removed obsolete init_pps and init_database;
  4164 
  4165 * deleted the obsolete tactical STATE, which was declared by
  4166     fun STATE tacfun st = tacfun st st;
  4167 
  4168 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  4169 (which abbreviates $HOME);
  4170 
  4171 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  4172 use isatool fixseq to adapt your ML programs (this works for fully
  4173 qualified references to the Sequence structure only!);
  4174 
  4175 * use_thy no longer requires writable current directory; it always
  4176 reloads .ML *and* .thy file, if either one is out of date;
  4177 
  4178 
  4179 *** Classical Reasoner ***
  4180 
  4181 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  4182 tactics that use classical reasoning to simplify a subgoal without
  4183 splitting it into several subgoals;
  4184 
  4185 * Safe_tac: like safe_tac but uses the default claset;
  4186 
  4187 
  4188 *** Simplifier ***
  4189 
  4190 * added simplification meta rules:
  4191     (asm_)(full_)simplify: simpset -> thm -> thm;
  4192 
  4193 * simplifier.ML no longer part of Pure -- has to be loaded by object
  4194 logics (again);
  4195 
  4196 * added prems argument to simplification procedures;
  4197 
  4198 * HOL, FOL, ZF: added infix function `addsplits':
  4199   instead of `<simpset> setloop (split_tac <thms>)'
  4200   you can simply write `<simpset> addsplits <thms>'
  4201 
  4202 
  4203 *** Syntax ***
  4204 
  4205 * TYPE('a) syntax for type reflection terms;
  4206 
  4207 * no longer handles consts with name "" -- declare as 'syntax' instead;
  4208 
  4209 * pretty printer: changed order of mixfix annotation preference (again!);
  4210 
  4211 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  4212 
  4213 
  4214 *** HOL ***
  4215 
  4216 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4217   with `addloop' of the simplifier to faciliate case splitting in premises.
  4218 
  4219 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  4220 
  4221 * HOL/Auth: new protocol proofs including some for the Internet
  4222   protocol TLS;
  4223 
  4224 * HOL/Map: new theory of `maps' a la VDM;
  4225 
  4226 * HOL/simplifier: simplification procedures nat_cancel_sums for
  4227 cancelling out common nat summands from =, <, <= (in)equalities, or
  4228 differences; simplification procedures nat_cancel_factor for
  4229 cancelling common factor from =, <, <= (in)equalities over natural
  4230 sums; nat_cancel contains both kinds of procedures, it is installed by
  4231 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  4232 
  4233 * HOL/simplifier: terms of the form
  4234   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  4235   are rewritten to
  4236   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  4237   and those of the form
  4238   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  4239   are rewritten to
  4240   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  4241 
  4242 * HOL/datatype
  4243   Each datatype `t' now comes with a theorem `split_t_case' of the form
  4244 
  4245   P(t_case f1 ... fn x) =
  4246      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  4247         ...
  4248        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  4249      )
  4250 
  4251   and a theorem `split_t_case_asm' of the form
  4252 
  4253   P(t_case f1 ... fn x) =
  4254     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  4255         ...
  4256        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  4257      )
  4258   which can be added to a simpset via `addsplits'. The existing theorems
  4259   expand_list_case and expand_option_case have been renamed to
  4260   split_list_case and split_option_case.
  4261 
  4262 * HOL/Arithmetic:
  4263   - `pred n' is automatically converted to `n-1'.
  4264     Users are strongly encouraged not to use `pred' any longer,
  4265     because it will disappear altogether at some point.
  4266   - Users are strongly encouraged to write "0 < n" rather than
  4267     "n ~= 0". Theorems and proof tools have been modified towards this
  4268     `standard'.
  4269 
  4270 * HOL/Lists:
  4271   the function "set_of_list" has been renamed "set" (and its theorems too);
  4272   the function "nth" now takes its arguments in the reverse order and
  4273   has acquired the infix notation "!" as in "xs!n".
  4274 
  4275 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  4276 
  4277 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  4278   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  4279 
  4280 * HOL/record: extensible records with schematic structural subtyping
  4281 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  4282 still lacks various theorems and concrete record syntax;
  4283 
  4284 
  4285 *** HOLCF ***
  4286 
  4287 * removed "axioms" and "generated by" sections;
  4288 
  4289 * replaced "ops" section by extended "consts" section, which is capable of
  4290   handling the continuous function space "->" directly;
  4291 
  4292 * domain package:
  4293   . proves theorems immediately and stores them in the theory,
  4294   . creates hierachical name space,
  4295   . now uses normal mixfix annotations (instead of cinfix...),
  4296   . minor changes to some names and values (for consistency),
  4297   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  4298   . separator between mutual domain defs: changed "," to "and",
  4299   . improved handling of sort constraints;  now they have to
  4300     appear on the left-hand side of the equations only;
  4301 
  4302 * fixed LAM <x,y,zs>.b syntax;
  4303 
  4304 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  4305 adm (%x. P (t x)), where P is chainfinite and t continuous;
  4306 
  4307 
  4308 *** FOL and ZF ***
  4309 
  4310 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4311   with `addloop' of the simplifier to faciliate case splitting in premises.
  4312 
  4313 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  4314 in HOL, they strip ALL and --> from proved theorems;
  4315 
  4316 
  4317 
  4318 New in Isabelle94-8 (May 1997)
  4319 ------------------------------
  4320 
  4321 *** General Changes ***
  4322 
  4323 * new utilities to build / run / maintain Isabelle etc. (in parts
  4324 still somewhat experimental); old Makefiles etc. still functional;
  4325 
  4326 * new 'Isabelle System Manual';
  4327 
  4328 * INSTALL text, together with ./configure and ./build scripts;
  4329 
  4330 * reimplemented type inference for greater efficiency, better error
  4331 messages and clean internal interface;
  4332 
  4333 * prlim command for dealing with lots of subgoals (an easier way of
  4334 setting goals_limit);
  4335 
  4336 
  4337 *** Syntax ***
  4338 
  4339 * supports alternative (named) syntax tables (parser and pretty
  4340 printer); internal interface is provided by add_modesyntax(_i);
  4341 
  4342 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  4343 be used in conjunction with the Isabelle symbol font; uses the
  4344 "symbols" syntax table;
  4345 
  4346 * added token_translation interface (may translate name tokens in
  4347 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  4348 the current print_mode); IMPORTANT: user print translation functions
  4349 are responsible for marking newly introduced bounds
  4350 (Syntax.mark_boundT);
  4351 
  4352 * token translations for modes "xterm" and "xterm_color" that display
  4353 names in bold, underline etc. or colors (which requires a color
  4354 version of xterm);
  4355 
  4356 * infixes may now be declared with names independent of their syntax;
  4357 
  4358 * added typed_print_translation (like print_translation, but may
  4359 access type of constant);
  4360 
  4361 
  4362 *** Classical Reasoner ***
  4363 
  4364 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  4365 some limitations.  Blast_tac...
  4366   + ignores addss, addbefore, addafter; this restriction is intrinsic
  4367   + ignores elimination rules that don't have the correct format
  4368         (the conclusion MUST be a formula variable)
  4369   + ignores types, which can make HOL proofs fail
  4370   + rules must not require higher-order unification, e.g. apply_type in ZF
  4371     [message "Function Var's argument not a bound variable" relates to this]
  4372   + its proof strategy is more general but can actually be slower
  4373 
  4374 * substitution with equality assumptions no longer permutes other
  4375 assumptions;
  4376 
  4377 * minor changes in semantics of addafter (now called addaltern); renamed
  4378 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  4379 (and access functions for it);
  4380 
  4381 * improved combination of classical reasoner and simplifier:
  4382   + functions for handling clasimpsets
  4383   + improvement of addss: now the simplifier is called _after_ the
  4384     safe steps.
  4385   + safe variant of addss called addSss: uses safe simplifications
  4386     _during_ the safe steps. It is more complete as it allows multiple
  4387     instantiations of unknowns (e.g. with slow_tac).
  4388 
  4389 *** Simplifier ***
  4390 
  4391 * added interface for simplification procedures (functions that
  4392 produce *proven* rewrite rules on the fly, depending on current
  4393 redex);
  4394 
  4395 * ordering on terms as parameter (used for ordered rewriting);
  4396 
  4397 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  4398 
  4399 * the solver is now split into a safe and an unsafe part.
  4400 This should be invisible for the normal user, except that the
  4401 functions setsolver and addsolver have been renamed to setSolver and
  4402 addSolver; added safe_asm_full_simp_tac;
  4403 
  4404 
  4405 *** HOL ***
  4406 
  4407 * a generic induction tactic `induct_tac' which works for all datatypes and
  4408 also for type `nat';
  4409 
  4410 * a generic case distinction tactic `exhaust_tac' which works for all
  4411 datatypes and also for type `nat';
  4412 
  4413 * each datatype comes with a function `size';
  4414 
  4415 * patterns in case expressions allow tuple patterns as arguments to
  4416 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  4417 
  4418 * primrec now also works with type nat;
  4419 
  4420 * recdef: a new declaration form, allows general recursive functions to be
  4421 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  4422 
  4423 * the constant for negation has been renamed from "not" to "Not" to
  4424 harmonize with FOL, ZF, LK, etc.;
  4425 
  4426 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  4427 infinite lists;
  4428 
  4429 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  4430 
  4431 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  4432 problems in commutative rings, using axiomatic type classes for + and *;
  4433 
  4434 * more examples in HOL/MiniML and HOL/Auth;
  4435 
  4436 * more default rewrite rules for quantifiers, union/intersection;
  4437 
  4438 * a new constant `arbitrary == @x.False';
  4439 
  4440 * HOLCF/IOA replaces old HOL/IOA;
  4441 
  4442 * HOLCF changes: derived all rules and arities
  4443   + axiomatic type classes instead of classes
  4444   + typedef instead of faking type definitions
  4445   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  4446   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  4447   + eliminated the types void, one, tr
  4448   + use unit lift and bool lift (with translations) instead of one and tr
  4449   + eliminated blift from Lift3.thy (use Def instead of blift)
  4450   all eliminated rules are derived as theorems --> no visible changes ;
  4451 
  4452 
  4453 *** ZF ***
  4454 
  4455 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  4456 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  4457 as ZF_cs addSIs [equalityI];
  4458 
  4459 
  4460 
  4461 New in Isabelle94-7 (November 96)
  4462 ---------------------------------
  4463 
  4464 * allowing negative levels (as offsets) in prlev and choplev;
  4465 
  4466 * super-linear speedup for large simplifications;
  4467 
  4468 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  4469 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  4470 FAIL); can suppress it using the command Delsimps (ex_simps @
  4471 all_simps); De Morgan laws are also now included, by default;
  4472 
  4473 * improved printing of ==>  :  ~:
  4474 
  4475 * new object-logic "Sequents" adds linear logic, while replacing LK
  4476 and Modal (thanks to Sara Kalvala);
  4477 
  4478 * HOL/Auth: correctness proofs for authentication protocols;
  4479 
  4480 * HOL: new auto_tac combines rewriting and classical reasoning (many
  4481 examples on HOL/Auth);
  4482 
  4483 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  4484 the rewriter and classical reasoner simultaneously;
  4485 
  4486 * function uresult no longer returns theorems in "standard" format;
  4487 regain previous version by: val uresult = standard o uresult;
  4488 
  4489 
  4490 
  4491 New in Isabelle94-6
  4492 -------------------
  4493 
  4494 * oracles -- these establish an interface between Isabelle and trusted
  4495 external reasoners, which may deliver results as theorems;
  4496 
  4497 * proof objects (in particular record all uses of oracles);
  4498 
  4499 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  4500 
  4501 * "constdefs" section in theory files;
  4502 
  4503 * "primrec" section (HOL) no longer requires names;
  4504 
  4505 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  4506 
  4507 
  4508 
  4509 New in Isabelle94-5
  4510 -------------------
  4511 
  4512 * reduced space requirements;
  4513 
  4514 * automatic HTML generation from theories;
  4515 
  4516 * theory files no longer require "..." (quotes) around most types;
  4517 
  4518 * new examples, including two proofs of the Church-Rosser theorem;
  4519 
  4520 * non-curried (1994) version of HOL is no longer distributed;
  4521 
  4522 
  4523 
  4524 New in Isabelle94-4
  4525 -------------------
  4526 
  4527 * greatly reduced space requirements;
  4528 
  4529 * theory files (.thy) no longer require \...\ escapes at line breaks;
  4530 
  4531 * searchable theorem database (see the section "Retrieving theorems" on
  4532 page 8 of the Reference Manual);
  4533 
  4534 * new examples, including Grabczewski's monumental case study of the
  4535 Axiom of Choice;
  4536 
  4537 * The previous version of HOL renamed to Old_HOL;
  4538 
  4539 * The new version of HOL (previously called CHOL) uses a curried syntax
  4540 for functions.  Application looks like f a b instead of f(a,b);
  4541 
  4542 * Mutually recursive inductive definitions finally work in HOL;
  4543 
  4544 * In ZF, pattern-matching on tuples is now available in all abstractions and
  4545 translates to the operator "split";
  4546 
  4547 
  4548 
  4549 New in Isabelle94-3
  4550 -------------------
  4551 
  4552 * new infix operator, addss, allowing the classical reasoner to
  4553 perform simplification at each step of its search.  Example:
  4554         fast_tac (cs addss ss)
  4555 
  4556 * a new logic, CHOL, the same as HOL, but with a curried syntax
  4557 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  4558 look like (a,b) instead of <a,b>;
  4559 
  4560 * PLEASE NOTE: CHOL will eventually replace HOL!
  4561 
  4562 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  4563 It translates to the operator "split".  A new theory of integers is available;
  4564 
  4565 * In ZF, integer numerals now denote two's-complement binary integers.
  4566 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  4567 
  4568 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  4569 of the Axiom of Choice;
  4570 
  4571 
  4572 
  4573 New in Isabelle94-2
  4574 -------------------
  4575 
  4576 * Significantly faster resolution;
  4577 
  4578 * the different sections in a .thy file can now be mixed and repeated
  4579 freely;
  4580 
  4581 * Database of theorems for FOL, HOL and ZF.  New
  4582 commands including qed, qed_goal and bind_thm store theorems in the database.
  4583 
  4584 * Simple database queries: return a named theorem (get_thm) or all theorems of
  4585 a given theory (thms_of), or find out what theory a theorem was proved in
  4586 (theory_of_thm);
  4587 
  4588 * Bugs fixed in the inductive definition and datatype packages;
  4589 
  4590 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  4591 and HOL_dup_cs obsolete;
  4592 
  4593 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  4594 have been removed;
  4595 
  4596 * Simpler definition of function space in ZF;
  4597 
  4598 * new results about cardinal and ordinal arithmetic in ZF;
  4599 
  4600 * 'subtype' facility in HOL for introducing new types as subsets of existing
  4601 types;
  4602 
  4603 
  4604 $Id$