NEWS
author haftmann
Mon Dec 18 08:21:35 2006 +0100 (2006-12-18)
changeset 21879 a3efbae45735
parent 21791 367477e8458b
child 21896 9a7949815a84
permissions -rw-r--r--
switched argument order in *.syntax lifters
     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 
    46 *** Document preparation ***
    47 
    48 * Added antiquotation @{theory name} which prints the given name,
    49 after checking that it refers to a valid ancestor theory in the
    50 current context.
    51 
    52 * Added antiquotations @{ML_type text} and @{ML_struct text} which
    53 check the given source text as ML type/structure, printing verbatim.
    54 
    55 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
    56 "c args == rhs" given in the current context.  (Any number of
    57 arguments may be given on the LHS.)
    58 
    59 
    60 
    61 *** Pure ***
    62 
    63 * class_package.ML offers a combination of axclasses and locales to
    64 achieve Haskell-like type classes in Isabelle. See
    65 HOL/ex/Classpackage.thy for examples.
    66 
    67 * Yet another code generator framework allows to generate executable
    68 code for ML and Haskell (including "class"es). A short usage sketch:
    69 
    70     internal compilation:
    71         code_gen <list of constants (term syntax)> (SML #)
    72     writing SML code to a file:
    73         code_gen <list of constants (term syntax)> (SML <filename>)
    74     writing Haskell code to a bunch of files:
    75         code_gen <list of constants (term syntax)> (Haskell <filename>)
    76 
    77 Reasonable default setup of framework in HOL/Main.
    78 
    79 See HOL/ex/Code*.thy for examples.
    80 
    81 Theorem attributs for selecting and transforming function equations theorems:
    82 
    83     [code fun]:       select a theorem as function equation for a specific constant
    84     [code nofun]:     deselect a theorem as function equation for a specific constant
    85     [code inline]:    select an equation theorem for unfolding (inlining) in place
    86     [code noinline]:  deselect an equation theorem for unfolding (inlining) in place
    87 
    88 User-defined serializations (target in {SML, Haskell}):
    89 
    90     code_const <and-list of constants (term syntax)>
    91       {(target) <and-list of const target syntax>}+
    92 
    93     code_type <and-list of type constructors>
    94       {(target) <and-list of type target syntax>}+
    95 
    96     code_instance <and-list of instances>
    97       {(target)}+
    98         where instance ::= <type constructor> :: <class>
    99 
   100     code_class <and_list of classes>
   101       {(target) <and-list of class target syntax>}+
   102         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
   103 
   104 For code_instance and code_class, target SML is silently ignored.
   105 
   106 See HOL theories and HOL/ex/Code*.thy for usage examples.  Doc/Isar/Advanced/Codegen/
   107 provides a tutorial.
   108 
   109 * Command 'no_translations' removes translation rules from theory
   110 syntax.
   111 
   112 * Overloaded definitions are now actually checked for acyclic
   113 dependencies.  The overloading scheme is slightly more general than
   114 that of Haskell98, although Isabelle does not demand an exact
   115 correspondence to type class and instance declarations.
   116 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
   117 exotic versions of overloading -- at the discretion of the user!
   118 
   119 Polymorphic constants are represented via type arguments, i.e. the
   120 instantiation that matches an instance against the most general
   121 declaration given in the signature.  For example, with the declaration
   122 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
   123 as c(nat).  Overloading is essentially simultaneous structural
   124 recursion over such type arguments.  Incomplete specification patterns
   125 impose global constraints on all occurrences, e.g. c('a * 'a) on the
   126 LHS means that more general c('a * 'b) will be disallowed on any RHS.
   127 Command 'print_theory' outputs the normalized system of recursive
   128 equations, see section "definitions".
   129 
   130 * Isar: improper proof element 'guess' is like 'obtain', but derives
   131 the obtained context from the course of reasoning!  For example:
   132 
   133   assume "EX x y. A x & B y"   -- "any previous fact"
   134   then guess x and y by clarify
   135 
   136 This technique is potentially adventurous, depending on the facts and
   137 proof tools being involved here.
   138 
   139 * Isar: known facts from the proof context may be specified as literal
   140 propositions, using ASCII back-quote syntax.  This works wherever
   141 named facts used to be allowed so far, in proof commands, proof
   142 methods, attributes etc.  Literal facts are retrieved from the context
   143 according to unification of type and term parameters.  For example,
   144 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
   145 theorems in the current context, then these are valid literal facts:
   146 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
   147 
   148 There is also a proof method "fact" which does the same composition
   149 for explicit goal states, e.g. the following proof texts coincide with
   150 certain special cases of literal facts:
   151 
   152   have "A" by fact                 ==  note `A`
   153   have "A ==> B" by fact           ==  note `A ==> B`
   154   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
   155   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
   156 
   157 * Isar: ":" (colon) is no longer a symbolic identifier character in
   158 outer syntax.  Thus symbolic identifiers may be used without
   159 additional white space in declarations like this: ``assume *: A''.
   160 
   161 * Isar: 'print_facts' prints all local facts of the current context,
   162 both named and unnamed ones.
   163 
   164 * Isar: 'def' now admits simultaneous definitions, e.g.:
   165 
   166   def x == "t" and y == "u"
   167 
   168 * Isar: added command 'unfolding', which is structurally similar to
   169 'using', but affects both the goal state and facts by unfolding given
   170 rewrite rules.  Thus many occurrences of the 'unfold' method or
   171 'unfolded' attribute may be replaced by first-class proof text.
   172 
   173 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
   174 and command 'unfolding' now all support object-level equalities
   175 (potentially conditional).  The underlying notion of rewrite rule is
   176 analogous to the 'rule_format' attribute, but *not* that of the
   177 Simplifier (which is usually more generous).
   178 
   179 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
   180 method expression within a sandbox consisting of the first N
   181 sub-goals, which need to exist.  For example, ``simp_all [3]''
   182 simplifies the first three sub-goals, while (rule foo, simp_all)[]
   183 simplifies all new goals that emerge from applying rule foo to the
   184 originally first one.
   185 
   186 * Isar: schematic goals are no longer restricted to higher-order
   187 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
   188 expected.
   189 
   190 * Isar: the conclusion of a long theorem statement is now either
   191 'shows' (a simultaneous conjunction, as before), or 'obtains'
   192 (essentially a disjunction of cases with local parameters and
   193 assumptions).  The latter allows to express general elimination rules
   194 adequately; in this notation common elimination rules look like this:
   195 
   196   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
   197     assumes "EX x. P x"
   198     obtains x where "P x"
   199 
   200   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
   201     assumes "A & B"
   202     obtains A and B
   203 
   204   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
   205     assumes "A | B"
   206     obtains
   207       A
   208     | B
   209 
   210 The subsequent classical rules even refer to the formal "thesis"
   211 explicitly:
   212 
   213   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
   214     obtains "~ thesis"
   215 
   216   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
   217     obtains "thesis ==> something"
   218 
   219 The actual proof of an 'obtains' statement is analogous to that of the
   220 Isar proof element 'obtain', only that there may be several cases.
   221 Optional case names may be specified in parentheses; these will be
   222 available both in the present proof and as annotations in the
   223 resulting rule, for later use with the 'cases' method (cf. attribute
   224 case_names).
   225 
   226 * Isar: the assumptions of a long theorem statement are available as
   227 "assms" fact in the proof context.  This is more appropriate than the
   228 (historical) "prems", which refers to all assumptions of the current
   229 context, including those from the target locale, proof body etc.
   230 
   231 * Isar: 'print_statement' prints theorems from the current theory or
   232 proof context in long statement form, according to the syntax of a
   233 top-level lemma.
   234 
   235 * Isar: 'obtain' takes an optional case name for the local context
   236 introduction rule (default "that").
   237 
   238 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
   239 explicit (is "_ ==> ?foo") in the rare cases where this still happens
   240 to occur.
   241 
   242 * Pure: syntax "CONST name" produces a fully internalized constant
   243 according to the current context.  This is particularly useful for
   244 syntax translations that should refer to internal constant
   245 representations independently of name spaces.
   246 
   247 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
   248 instead of "FOO ". This allows multiple binder declarations to coexist
   249 in the same context.  INCOMPATIBILITY.
   250 
   251 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
   252 primitive that also works in a locale context (both for constants and
   253 fixed variables).  Type declaration and internal syntactic
   254 representation of given constants retrieved from the context.
   255 
   256 * Isar/locales: new derived specification elements 'axiomatization',
   257 'definition', 'abbreviation', which support type-inference, admit
   258 object-level specifications (equality, equivalence).  See also the
   259 isar-ref manual.  Examples:
   260 
   261   axiomatization
   262     eq  (infix "===" 50) where
   263     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
   264 
   265   definition "f x y = x + y + 1"
   266   definition g where "g x = f x x"
   267 
   268   abbreviation
   269     neq  (infix "=!=" 50) where
   270     "x =!= y == ~ (x === y)"
   271 
   272 These specifications may be also used in a locale context.  Then the
   273 constants being introduced depend on certain fixed parameters, and the
   274 constant name is qualified by the locale base name.  An internal
   275 abbreviation takes care for convenient input and output, making the
   276 parameters implicit and using the original short name.  See also
   277 HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
   278 entities from a monomorphic theory.
   279 
   280 Presently, abbreviations are only available 'in' a target locale, but
   281 not inherited by general import expressions.  Also note that
   282 'abbreviation' may be used as a type-safe replacement for 'syntax' +
   283 'translations' in common applications.
   284 
   285 Concrete syntax is attached to specified constants in internal form,
   286 independently of name spaces.  The parse tree representation is
   287 slightly different -- use 'notation' instead of raw 'syntax', and
   288 'translations' with explicit "CONST" markup to accommodate this.
   289 
   290 * Pure: command 'print_abbrevs' prints all constant abbreviations of
   291 the current context.  Print mode "no_abbrevs" prevents inversion of
   292 abbreviations on output.
   293 
   294 * Isar/locales: improved parameter handling:
   295 - use of locales "var" and "struct" no longer necessary;
   296 - parameter renamings are no longer required to be injective.
   297   This enables, for example, to define a locale for endomorphisms thus:
   298   locale endom = homom mult mult h.
   299 
   300 * Isar/locales: changed the way locales with predicates are defined.
   301 Instead of accumulating the specification, the imported expression is
   302 now an interpretation.
   303 INCOMPATIBILITY: different normal form of locale expressions.
   304 In particular, in interpretations of locales with predicates,
   305 goals repesenting already interpreted fragments are not removed
   306 automatically.  Use methods `intro_locales' and `unfold_locales'; see below.
   307 
   308 * Isar/locales: new methods `intro_locales' and `unfold_locales' provide
   309 backward reasoning on locales predicates.  The methods are aware of
   310 interpretations and discharge corresponding goals.  `intro_locales' is
   311 less aggressive then `unfold_locales' and does not unfold predicates to
   312 assumptions.
   313 
   314 * Isar/locales: the order in which locale fragments are accumulated
   315 has changed.  This enables to override declarations from fragments
   316 due to interpretations -- for example, unwanted simp rules.
   317 
   318 * Provers/induct: improved internal context management to support
   319 local fixes and defines on-the-fly.  Thus explicit meta-level
   320 connectives !! and ==> are rarely required anymore in inductive goals
   321 (using object-logic connectives for this purpose has been long
   322 obsolete anyway).  The subsequent proof patterns illustrate advanced
   323 techniques of natural induction; general datatypes and inductive sets
   324 work analogously (see also src/HOL/Lambda for realistic examples).
   325 
   326 (1) This is how to ``strengthen'' an inductive goal wrt. certain
   327 parameters:
   328 
   329   lemma
   330     fixes n :: nat and x :: 'a
   331     assumes a: "A n x"
   332     shows "P n x"
   333     using a                     -- {* make induct insert fact a *}
   334   proof (induct n arbitrary: x) -- {* generalize goal to "!!x. A n x ==> P n x" *}
   335     case 0
   336     show ?case sorry
   337   next
   338     case (Suc n)
   339     note `!!x. A n x ==> P n x` -- {* induction hypothesis, according to induction rule *}
   340     note `A (Suc n) x`          -- {* induction premise, stemming from fact a *}
   341     show ?case sorry
   342   qed
   343 
   344 (2) This is how to perform induction over ``expressions of a certain
   345 form'', using a locally defined inductive parameter n == "a x"
   346 together with strengthening (the latter is usually required to get
   347 sufficiently flexible induction hypotheses):
   348 
   349   lemma
   350     fixes a :: "'a => nat"
   351     assumes a: "A (a x)"
   352     shows "P (a x)"
   353     using a
   354   proof (induct n == "a x" arbitrary: x)
   355     ...
   356 
   357 See also HOL/Isar_examples/Puzzle.thy for an application of the this
   358 particular technique.
   359 
   360 (3) This is how to perform existential reasoning ('obtains' or
   361 'obtain') by induction, while avoiding explicit object-logic
   362 encodings:
   363 
   364   lemma
   365     fixes n :: nat
   366     obtains x :: 'a where "P n x" and "Q n x"
   367   proof (induct n arbitrary: thesis)
   368     case 0
   369     obtain x where "P 0 x" and "Q 0 x" sorry
   370     then show thesis by (rule 0)
   371   next
   372     case (Suc n)
   373     obtain x where "P n x" and "Q n x" by (rule Suc.hyps)
   374     obtain x where "P (Suc n) x" and "Q (Suc n) x" sorry
   375     then show thesis by (rule Suc.prems)
   376   qed
   377 
   378 Here the 'arbitrary: thesis' specification essentially modifies the
   379 scope of the formal thesis parameter, in order to the get the whole
   380 existence statement through the induction as expected.
   381 
   382 * Provers/induct: mutual induction rules are now specified as a list
   383 of rule sharing the same induction cases.  HOL packages usually
   384 provide foo_bar.inducts for mutually defined items foo and bar
   385 (e.g. inductive sets or datatypes).  INCOMPATIBILITY, users need to
   386 specify mutual induction rules differently, i.e. like this:
   387 
   388   (induct rule: foo_bar.inducts)
   389   (induct set: foo bar)
   390   (induct type: foo bar)
   391 
   392 The ML function ProjectRule.projections turns old-style rules into the
   393 new format.
   394 
   395 * Provers/induct: improved handling of simultaneous goals.  Instead of
   396 introducing object-level conjunction, the statement is now split into
   397 several conclusions, while the corresponding symbolic cases are
   398 nested accordingly.  INCOMPATIBILITY, proofs need to be structured
   399 explicitly.  For example:
   400 
   401   lemma
   402     fixes n :: nat
   403     shows "P n" and "Q n"
   404   proof (induct n)
   405     case 0 case 1
   406     show "P 0" sorry
   407   next
   408     case 0 case 2
   409     show "Q 0" sorry
   410   next
   411     case (Suc n) case 1
   412     note `P n` and `Q n`
   413     show "P (Suc n)" sorry
   414   next
   415     case (Suc n) case 2
   416     note `P n` and `Q n`
   417     show "Q (Suc n)" sorry
   418   qed
   419 
   420 The split into subcases may be deferred as follows -- this is
   421 particularly relevant for goal statements with local premises.
   422 
   423   lemma
   424     fixes n :: nat
   425     shows "A n ==> P n" and "B n ==> Q n"
   426   proof (induct n)
   427     case 0
   428     {
   429       case 1
   430       note `A 0`
   431       show "P 0" sorry
   432     next
   433       case 2
   434       note `B 0`
   435       show "Q 0" sorry
   436     }
   437   next
   438     case (Suc n)
   439     note `A n ==> P n` and `B n ==> Q n`
   440     {
   441       case 1
   442       note `A (Suc n)`
   443       show "P (Suc n)" sorry
   444     next
   445       case 2
   446       note `B (Suc n)`
   447       show "Q (Suc n)" sorry
   448     }
   449   qed
   450 
   451 If simultaneous goals are to be used with mutual rules, the statement
   452 needs to be structured carefully as a two-level conjunction, using
   453 lists of propositions separated by 'and':
   454 
   455   lemma
   456     shows "a : A ==> P1 a"
   457           "a : A ==> P2 a"
   458       and "b : B ==> Q1 b"
   459           "b : B ==> Q2 b"
   460           "b : B ==> Q3 b"
   461   proof (induct set: A B)
   462 
   463 * Provers/induct: support coinduction as well.  See
   464 src/HOL/Library/Coinductive_List.thy for various examples.
   465 
   466 * Attribute "symmetric" produces result with standardized schematic
   467 variables (index 0).  Potential INCOMPATIBILITY.
   468 
   469 * Simplifier: by default the simplifier trace only shows top level rewrites
   470 now. That is, trace_simp_depth_limit is set to 1 by default. Thus there is
   471 less danger of being flooded by the trace. The trace indicates where parts
   472 have been suppressed.
   473   
   474 * Provers/classical: removed obsolete classical version of elim_format
   475 attribute; classical elim/dest rules are now treated uniformly when
   476 manipulating the claset.
   477 
   478 * Provers/classical: stricter checks to ensure that supplied intro,
   479 dest and elim rules are well-formed; dest and elim rules must have at
   480 least one premise.
   481 
   482 * Provers/classical: attributes dest/elim/intro take an optional
   483 weight argument for the rule (just as the Pure versions).  Weights are
   484 ignored by automated tools, but determine the search order of single
   485 rule steps.
   486 
   487 * Syntax: input syntax now supports dummy variable binding "%_. b",
   488 where the body does not mention the bound variable.  Note that dummy
   489 patterns implicitly depend on their context of bounds, which makes
   490 "{_. _}" match any set comprehension as expected.  Potential
   491 INCOMPATIBILITY -- parse translations need to cope with syntactic
   492 constant "_idtdummy" in the binding position.
   493 
   494 * Syntax: removed obsolete syntactic constant "_K" and its associated
   495 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
   496 for example "A -> B" => "Pi A (%_. B)".
   497 
   498 * Pure: 'class_deps' command visualizes the subclass relation, using
   499 the graph browser tool.
   500 
   501 * Pure: 'print_theory' now suppresses entities with internal name
   502 (trailing "_") by default; use '!' option for full details.
   503 
   504 
   505 *** HOL ***
   506 
   507 * New syntactic class "size"; overloaded constant "size" now
   508 has type "'a::size ==> bool"
   509 
   510 * Constants "Divides.op div", "Divides.op mod" and "Divides.op dvd" no named
   511   "Divides.div", "Divides.mod" and "Divides.dvd"
   512   INCOMPATIBILITY for ML code directly refering to constant names.
   513 
   514 * Replaced "auto_term" by the conceptually simpler method "relation",
   515 which just applies the instantiated termination rule with no further
   516 simplifications.
   517 INCOMPATIBILITY: 
   518 Replace 
   519         termination by (auto_term "MYREL")
   520 with 
   521         termination by (relation "MYREL") auto
   522 
   523 * Automated termination proofs "by lexicographic_order" are now
   524 included in the abbreviated function command "fun". No explicit
   525 "termination" command is necessary anymore.
   526 INCOMPATIBILITY: If a "fun"-definition cannot be proved terminating by
   527 a lexicographic size order, then the command fails. Use the expanded
   528 version "function" for these cases.
   529 
   530 * New method "lexicographic_order" automatically synthesizes
   531 termination relations as lexicographic combinations of size measures. 
   532 Usage for (function package) termination proofs:
   533 
   534 termination 
   535 by lexicographic_order
   536 
   537 * Records: generalised field-update to take a function on the field 
   538 rather than the new value: r(|A := x|) is translated to A_update (K x) r
   539 The K-combinator that is internally used is called K_record.
   540 INCOMPATIBILITY: Usage of the plain update functions has to be
   541 adapted.
   542  
   543 * axclass "semiring_0" now contains annihilation axioms 
   544 ("x * 0 = 0","0 * x = 0"), which are required for a semiring. Richer 
   545 structures do not inherit from semiring_0 anymore, because this property 
   546 is a theorem there, not an axiom.
   547 INCOMPATIBILITY: In instances of semiring_0, there is more to prove, but 
   548 this is mostly trivial.
   549 
   550 * axclass "recpower" was generalized to arbitrary monoids, not just 
   551 commutative semirings.
   552 INCOMPATIBILITY: If you use recpower and need commutativity or a semiring
   553 property, add the corresponding classes.
   554 
   555 * Locale Lattic_Locales.partial_order changed (to achieve consistency with
   556 axclass order):
   557 - moved to Orderings.partial_order
   558 - additional parameter ``less''
   559 INCOMPATIBILITY.
   560 
   561 * Constant "List.list_all2" in List.thy now uses authentic syntax.
   562 INCOMPATIBILITY: translations containing list_all2 may go wrong. On Isar
   563 level, use abbreviations instead.
   564 
   565 * Constant "List.op mem" in List.thy now has proper name: "List.memberl"
   566 INCOMPATIBILITY: rarely occuring name references (e.g. ``List.op mem.simps'')
   567 require renaming (e.g. ``List.memberl.simps'').
   568 
   569 * Renamed constants in HOL.thy:
   570     0      ~> HOL.zero
   571     1      ~> HOL.one
   572 INCOMPATIBILITY: ML code directly refering to constant names may need adaption
   573 This in general only affects hand-written proof tactics, simprocs and so on.
   574 
   575 * New theory Code_Generator providing class 'eq',
   576 allowing for code generation with polymorphic equality.
   577 
   578 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has been
   579 abandoned in favour of plain 'int'. INCOMPATIBILITY -- Significant changes
   580 for setting up numeral syntax for types:
   581 
   582   - new constants Numeral.pred and Numeral.succ instead
   583       of former Numeral.bin_pred and Numeral.bin_succ.
   584   - Use integer operations instead of bin_add, bin_mult and so on.
   585   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
   586   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
   587 
   588 See HOL/Integ/IntArith.thy for an example setup.
   589 
   590 * New top level command 'normal_form' computes the normal form of a term
   591 that may contain free variables. For example 'normal_form "rev[a,b,c]"'
   592 prints '[b,c,a]'. This command is suitable for heavy-duty computations
   593 because the functions are compiled to ML first.
   594 INCOMPATIBILITY: new keywords 'normal_form' must quoted when used as
   595 an identifier.
   596 
   597 * Alternative iff syntax "A <-> B" for equality on bool (with priority
   598 25 like -->); output depends on the "iff" print_mode, the default is
   599 "A = B" (with priority 50).
   600 
   601 * Renamed constants in HOL.thy and Orderings.thy:
   602     op +   ~> HOL.plus
   603     op -   ~> HOL.minus
   604     uminus ~> HOL.uminus
   605     op *   ~> HOL.times
   606     op <   ~> Orderings.less
   607     op <=  ~> Orderings.less_eq
   608 
   609 Adaptions may be required in the following cases:
   610 
   611 a) User-defined constants using any of the names "plus", "minus", "times",
   612 "less" or "less_eq". The standard syntax translations for "+", "-" and "*"
   613 may go wrong.
   614 INCOMPATIBILITY: use more specific names.
   615 
   616 b) Variables named "plus", "minus", "times", "less", "less_eq"
   617 INCOMPATIBILITY: use more specific names.
   618 
   619 c) Permutative equations (e.g. "a + b = b + a")
   620 Since the change of names also changes the order of terms, permutative
   621 rewrite rules may get applied in a different order. Experience shows that
   622 this is rarely the case (only two adaptions in the whole Isabelle
   623 distribution).
   624 INCOMPATIBILITY: rewrite proofs
   625 
   626 d) ML code directly refering to constant names
   627 This in general only affects hand-written proof tactics, simprocs and so on.
   628 INCOMPATIBILITY: grep your sourcecode and replace names.
   629 
   630 * Relations less (<) and less_eq (<=) are also available on type bool.
   631 Modified syntax to disallow nesting without explicit parentheses,
   632 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".
   633 
   634 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
   635 
   636 * Relation composition operator "op O" now has precedence 75 and binds
   637 stronger than union and intersection. INCOMPATIBILITY.
   638 
   639 * The old set interval syntax "{m..n(}" (and relatives) has been removed.
   640   Use "{m..<n}" (and relatives) instead.
   641 
   642 * In the context of the assumption "~(s = t)" the Simplifier rewrites
   643 "t = s" to False (by simproc "neq_simproc").  For backward
   644 compatibility this can be disabled by ML "reset use_neq_simproc".
   645 
   646 * "m dvd n" where m and n are numbers is evaluated to True/False by simp.
   647 
   648 * Theorem Cons_eq_map_conv no longer has attribute `simp'.
   649 
   650 * Theorem setsum_mult renamed to setsum_right_distrib.
   651 
   652 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
   653 'rule' method.
   654 
   655 * Tactics 'sat' and 'satx' reimplemented, several improvements: goals
   656 no longer need to be stated as "<prems> ==> False", equivalences (i.e.
   657 "=" on type bool) are handled, variable names of the form "lit_<n>"
   658 are no longer reserved, significant speedup.
   659 
   660 * Tactics 'sat' and 'satx' can now replay MiniSat proof traces.  zChaff is
   661 still supported as well.
   662 
   663 * inductive and datatype: provide projections of mutual rules, bundled
   664 as foo_bar.inducts;
   665 
   666 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to Library.
   667 
   668 * Library: moved theory Accessible_Part to main HOL.
   669 
   670 * Library: added theory Coinductive_List of potentially infinite lists
   671 as greatest fixed-point.
   672 
   673 * Library: added theory AssocList which implements (finite) maps as
   674 association lists.
   675 
   676 * New proof method "evaluation" for efficiently solving a goal (i.e. a
   677 boolean expression) by compiling it to ML. The goal is "proved" (via
   678 the oracle "Evaluation") if it evaluates to True.
   679 
   680 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
   681 also when invoked by the simplifier.  This results in the simplifier
   682 being more powerful on arithmetic goals.  INCOMPATIBILITY.  Set
   683 fast_arith_split_limit to 0 to obtain the old behavior.
   684 
   685 * Support for hex (0x20) and binary (0b1001) numerals. 
   686 
   687 * New method: reify eqs (t), where eqs are equations for an
   688 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
   689 parameter, computes a term s::'b and a list xs::'a list and proves the
   690 theorem I xs s = t. This is also known as reification or quoting. The
   691 resulting theorem is applied to the subgoal to substitute t with I xs
   692 s.  If t is omitted, the subgoal itself is reified.
   693 
   694 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
   695 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
   696 where f is supposed to be a computable function (in the sense of code
   697 generattion). The method uses reify to compute s and xs as above then
   698 applies corr_thm and uses normalization by evaluation to "prove" f s =
   699 r and finally gets the theorem t = r, which is again applied to the
   700 subgoal. An Example is available in HOL/ex/ReflectionEx.thy.
   701 
   702 * Reflection: Automatic refification now handels binding, an example
   703 is available in HOL/ex/ReflectionEx.thy
   704 
   705 
   706 *** HOL-Algebra ***
   707 
   708 * Formalisation of ideals and the quotient construction over rings.
   709 
   710 * Order and lattice theory no longer based on records.
   711 INCOMPATIBILITY.
   712 
   713 * Method algebra is now set up via an attribute.  For examples see
   714 CRing.thy.  INCOMPATIBILITY: the method is now weaker on combinations
   715 of algebraic structures.
   716 
   717 * Renamed `CRing.thy' to `Ring.thy'.  INCOMPATIBILITY.
   718 
   719 
   720 *** HOL-Complex ***
   721 
   722 * Theory Real: new method ferrack implements quantifier elimination
   723 for linear arithmetic over the reals. The quantifier elimination
   724 feature is used only for decision, for compatibility with arith. This
   725 means a goal is either solved or left unchanged, no simplification.
   726 
   727 * Real: New axiomatic classes formalize real normed vector spaces and
   728 algebras, using new overloaded constants scaleR :: real => 'a => 'a
   729 and norm :: 'a => real.
   730 
   731 * Real: New constant of_real :: real => 'a::real_algebra_1 injects from
   732 reals into other types. The overloaded constant Reals :: 'a set is now
   733 defined as range of_real; potential INCOMPATIBILITY.
   734 
   735 * Hyperreal: Several constants that previously worked only for the reals
   736 have been generalized, so they now work over arbitrary vector spaces. Type
   737 annotations may need to be added in some cases; potential INCOMPATIBILITY.
   738 
   739   Infinitesimal  :: ('a::real_normed_vector) star set"
   740   HFinite        :: ('a::real_normed_vector) star set"
   741   HInfinite      :: ('a::real_normed_vector) star set"
   742   approx         :: ('a::real_normed_vector) star => 'a star => bool
   743   monad          :: ('a::real_normed_vector) star => 'a star set
   744   galaxy         :: ('a::real_normed_vector) star => 'a star set
   745   (NS)LIMSEQ     :: [nat, 'a::real_normed_vector, 'a] => bool
   746   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
   747   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
   748   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
   749   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
   750   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
   751   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
   752 
   753 * Complex: Some complex-specific constants are now abbreviations for
   754 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod = hnorm.
   755 Other constants have been entirely removed in favor of the polymorphic
   756 versions (INCOMPATIBILITY):
   757 
   758   approx        <-- capprox
   759   HFinite       <-- CFinite
   760   HInfinite     <-- CInfinite
   761   Infinitesimal <-- CInfinitesimal
   762   monad         <-- cmonad
   763   galaxy        <-- cgalaxy
   764   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
   765   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
   766   (ns)deriv     <-- (ns)cderiv
   767 
   768 
   769 *** ML ***
   770 
   771 * Pure/Isar/args.ML & Pure/Isar/method.ML
   772 
   773 switched argument order in *.syntax lifters.
   774 
   775 * Pure/table:
   776 
   777 Function `...tab.foldl` removed.
   778 INCOMPATIBILITY: use `...tabfold` instead
   779 
   780 * Pure/library:
   781 
   782 `gen_rem(s)` abandoned in favour of `remove` / `subtract`.
   783 INCOMPATIBILITY:
   784 rewrite "gen_rem eq (xs, x)" to "remove (eq o swap) x xs"
   785 rewrite "gen_rems eq (xs, ys)" to "subtract (eq o swap) ys xs"
   786 drop "swap" if "eq" is symmetric.
   787 
   788 * Pure/library:
   789 
   790 infixes `ins` `ins_string` `ins_int` have been abandoned in favour of `insert`.
   791 INCOMPATIBILITY: rewrite "x ins(_...) xs" to "insert (op =) x xs"
   792 
   793 * Pure/General/susp.ML:
   794 
   795 New module for delayed evaluations.
   796 
   797 * Pure/library:
   798 
   799 Semantically identical functions "equal_list" and "eq_list" have been
   800 unified to "eq_list".
   801 
   802 * Pure/library:
   803 
   804   val burrow: ('a list -> 'b list) -> 'a list list -> 'b list list
   805   val fold_burrow: ('a list -> 'c -> 'b list * 'd) -> 'a list list -> 'c -> 'b list list * 'd
   806 
   807 The semantics of "burrow" is: "take a function with *simulatanously*
   808 transforms a list of value, and apply it *simulatanously* to a list of
   809 list of values of the appropriate type". Confer this with "map" which
   810 would *not* apply its argument function simulatanously but in
   811 sequence. "fold_burrow" has an additional context.
   812 
   813 Both actually avoid the usage of "unflat" since they hide away
   814 "unflat" from the user.
   815 
   816 * Pure/library: functions map2 and fold2 with curried syntax for
   817 simultanous mapping and folding:
   818 
   819     val map2: ('a -> 'b -> 'c) -> 'a list -> 'b list -> 'c list
   820     val fold2: ('a -> 'b -> 'c -> 'c) -> 'a list -> 'b list -> 'c -> 'c
   821 
   822 * Pure/library: indexed lists - some functions in the Isabelle library
   823 treating lists over 'a as finite mappings from [0...n] to 'a have been
   824 given more convenient names and signatures reminiscent of similar
   825 functions for alists, tables, etc:
   826 
   827   val nth: 'a list -> int -> 'a 
   828   val nth_map: int -> ('a -> 'a) -> 'a list -> 'a list
   829   val fold_index: (int * 'a -> 'b -> 'b) -> 'a list -> 'b -> 'b
   830 
   831 Note that fold_index starts counting at index 0, not 1 like foldln
   832 used to.
   833 
   834 * Pure/library: general ``divide_and_conquer'' combinator on lists.
   835 
   836 * Pure/General/name_mangler.ML provides a functor for generic name
   837 mangling (bijective mapping from expression values to strings).
   838 
   839 * Pure/General/rat.ML implements rational numbers.
   840 
   841 * Pure/General/table.ML: the join operations now works via exceptions
   842 DUP/SAME instead of type option.  This is simpler in simple cases, and
   843 admits slightly more efficient complex applications.
   844 
   845 * Pure: datatype Context.generic joins theory/Proof.context and
   846 provides some facilities for code that works in either kind of
   847 context, notably GenericDataFun for uniform theory and proof data.
   848 
   849 * Pure: 'advanced' translation functions (parse_translation etc.) now
   850 use Context.generic instead of just theory.
   851 
   852 * Pure: simplified internal attribute type, which is now always
   853 Context.generic * thm -> Context.generic * thm.  Global (theory)
   854 vs. local (Proof.context) attributes have been discontinued, while
   855 minimizing code duplication.  Thm.rule_attribute and
   856 Thm.declaration_attribute build canonical attributes; see also
   857 structure Context for further operations on Context.generic, notably
   858 GenericDataFun.  INCOMPATIBILITY, need to adapt attribute type
   859 declarations and definitions.
   860 
   861 * Pure/kernel: consts certification ignores sort constraints given in
   862 signature declarations.  (This information is not relevant to the
   863 logic, but only for type inference.)  IMPORTANT INTERNAL CHANGE.
   864 
   865 * Pure: axiomatic type classes are now purely definitional, with
   866 explicit proofs of class axioms and super class relations performed
   867 internally.  See Pure/axclass.ML for the main internal interfaces --
   868 notably AxClass.define_class supercedes AxClass.add_axclass, and
   869 AxClass.axiomatize_class/classrel/arity supercede
   870 Sign.add_classes/classrel/arities.
   871 
   872 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
   873 global/local versions on theory vs. Proof.context have been
   874 discontinued; Attrib.syntax and Method.syntax have been adapted
   875 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
   876 attributes, methods, etc.
   877 
   878 * Pure: several functions of signature "... -> theory -> theory * ..."
   879 have been reoriented to "... -> theory -> ... * theory" in order to
   880 allow natural usage in combination with the ||>, ||>>, |-> and
   881 fold_map combinators.
   882 
   883 * Pure: official theorem names (closed derivations) and additional
   884 comments (tags) are now strictly separate.  Name hints -- which are
   885 maintained as tags -- may be attached any time without affecting the
   886 derivation.
   887 
   888 * Pure: primitive rule lift_rule now takes goal cterm instead of an
   889 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
   890 achieve the old behaviour.
   891 
   892 * Pure: the "Goal" constant is now called "prop", supporting a
   893 slightly more general idea of ``protecting'' meta-level rule
   894 statements.
   895 
   896 * Pure: Logic.(un)varify only works in a global context, which is now
   897 enforced instead of silently assumed.  INCOMPATIBILITY, may use
   898 Logic.legacy_(un)varify as temporary workaround.
   899 
   900 * Pure: structure Name provides scalable operations for generating
   901 internal variable names, notably Name.variants etc.  This replaces
   902 some popular functions from term.ML:
   903 
   904   Term.variant		->  Name.variant
   905   Term.variantlist	->  Name.variant_list  (*canonical argument order*)
   906   Term.invent_names	->  Name.invent_list
   907 
   908 Note that low-level renaming rarely occurs in new code -- operations
   909 from structure Variable are used instead (see below).
   910 
   911 * Pure: structure Variable provides fundamental operations for proper
   912 treatment of fixed/schematic variables in a context.  For example,
   913 Variable.import introduces fixes for schematics of given facts and
   914 Variable.export reverses the effect (up to renaming) -- this replaces
   915 various freeze_thaw operations.
   916 
   917 * Pure: structure Goal provides simple interfaces for
   918 init/conclude/finish and tactical prove operations (replacing former
   919 Tactic.prove).  Goal.prove is the canonical way to prove results
   920 within a given context; Goal.prove_global is a degraded version for
   921 theory level goals, including a global Drule.standard.  Note that
   922 OldGoals.prove_goalw_cterm has long been obsolete, since it is
   923 ill-behaved in a local proof context (e.g. with local fixes/assumes or
   924 in a locale context).
   925 
   926 * Isar: simplified treatment of user-level errors, using exception
   927 ERROR of string uniformly.  Function error now merely raises ERROR,
   928 without any side effect on output channels.  The Isar toplevel takes
   929 care of proper display of ERROR exceptions.  ML code may use plain
   930 handle/can/try; cat_error may be used to concatenate errors like this:
   931 
   932   ... handle ERROR msg => cat_error msg "..."
   933 
   934 Toplevel ML code (run directly or through the Isar toplevel) may be
   935 embedded into the Isar toplevel with exception display/debug like
   936 this:
   937 
   938   Isar.toplevel (fn () => ...)
   939 
   940 INCOMPATIBILITY, removed special transform_error facilities, removed
   941 obsolete variants of user-level exceptions (ERROR_MESSAGE,
   942 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
   943 -- use plain ERROR instead.
   944 
   945 * Isar: theory setup now has type (theory -> theory), instead of a
   946 list.  INCOMPATIBILITY, may use #> to compose setup functions.
   947 
   948 * Isar: installed ML toplevel pretty printer for type Proof.context,
   949 subject to ProofContext.debug/verbose flags.
   950 
   951 * Isar: Toplevel.theory_to_proof admits transactions that modify the
   952 theory before entering a proof state.  Transactions now always see a
   953 quasi-functional intermediate checkpoint, both in interactive and
   954 batch mode.
   955 
   956 * Simplifier: the simpset of a running simplification process now
   957 contains a proof context (cf. Simplifier.the_context), which is the
   958 very context that the initial simpset has been retrieved from (by
   959 simpset_of/local_simpset_of).  Consequently, all plug-in components
   960 (solver, looper etc.) may depend on arbitrary proof data.
   961 
   962 * Simplifier.inherit_context inherits the proof context (plus the
   963 local bounds) of the current simplification process; any simproc
   964 etc. that calls the Simplifier recursively should do this!  Removed
   965 former Simplifier.inherit_bounds, which is already included here --
   966 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
   967 specify an explicit context using Simplifier.context/theory_context.
   968 
   969 * Simplifier/Classical Reasoner: more abstract interfaces
   970 change_simpset/claset for modifying the simpset/claset reference of a
   971 theory; raw versions simpset/claset_ref etc. have been discontinued --
   972 INCOMPATIBILITY.
   973 
   974 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
   975 "Trueprop" etc.
   976 
   977 
   978 *** System ***
   979 
   980 * settings: ML_IDENTIFIER -- which is appended to user specific heap
   981 locations -- now includes the Isabelle version identifier as well.
   982 This simplifies use of multiple Isabelle installations.
   983 
   984 * isabelle-process: option -S (secure mode) disables some critical
   985 operations, notably runtime compilation and evaluation of ML source
   986 code.
   987 
   988 
   989 New in Isabelle2005 (October 2005)
   990 ----------------------------------
   991 
   992 *** General ***
   993 
   994 * Theory headers: the new header syntax for Isar theories is
   995 
   996   theory <name>
   997   imports <theory1> ... <theoryN>
   998   uses <file1> ... <fileM>
   999   begin
  1000 
  1001 where the 'uses' part is optional.  The previous syntax
  1002 
  1003   theory <name> = <theory1> + ... + <theoryN>:
  1004 
  1005 will disappear in the next release.  Use isatool fixheaders to convert
  1006 existing theory files.  Note that there is no change in ancient
  1007 non-Isar theories now, but these will disappear soon.
  1008 
  1009 * Theory loader: parent theories can now also be referred to via
  1010 relative and absolute paths.
  1011 
  1012 * Command 'find_theorems' searches for a list of criteria instead of a
  1013 list of constants. Known criteria are: intro, elim, dest, name:string,
  1014 simp:term, and any term. Criteria can be preceded by '-' to select
  1015 theorems that do not match. Intro, elim, dest select theorems that
  1016 match the current goal, name:s selects theorems whose fully qualified
  1017 name contain s, and simp:term selects all simplification rules whose
  1018 lhs match term.  Any other term is interpreted as pattern and selects
  1019 all theorems matching the pattern. Available in ProofGeneral under
  1020 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  1021 
  1022   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  1023 
  1024 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  1025 matching the current goal as introduction rule and not having "HOL."
  1026 in their name (i.e. not being defined in theory HOL).
  1027 
  1028 * Command 'thms_containing' has been discontinued in favour of
  1029 'find_theorems'; INCOMPATIBILITY.
  1030 
  1031 * Communication with Proof General is now 8bit clean, which means that
  1032 Unicode text in UTF-8 encoding may be used within theory texts (both
  1033 formal and informal parts).  Cf. option -U of the Isabelle Proof
  1034 General interface.  Here are some simple examples (cf. src/HOL/ex):
  1035 
  1036   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  1037   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  1038 
  1039 * Improved efficiency of the Simplifier and, to a lesser degree, the
  1040 Classical Reasoner.  Typical big applications run around 2 times
  1041 faster.
  1042 
  1043 
  1044 *** Document preparation ***
  1045 
  1046 * Commands 'display_drafts' and 'print_drafts' perform simple output
  1047 of raw sources.  Only those symbols that do not require additional
  1048 LaTeX packages (depending on comments in isabellesym.sty) are
  1049 displayed properly, everything else is left verbatim.  isatool display
  1050 and isatool print are used as front ends (these are subject to the
  1051 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  1052 
  1053 * Command tags control specific markup of certain regions of text,
  1054 notably folding and hiding.  Predefined tags include "theory" (for
  1055 theory begin and end), "proof" for proof commands, and "ML" for
  1056 commands involving ML code; the additional tags "visible" and
  1057 "invisible" are unused by default.  Users may give explicit tag
  1058 specifications in the text, e.g. ''by %invisible (auto)''.  The
  1059 interpretation of tags is determined by the LaTeX job during document
  1060 preparation: see option -V of isatool usedir, or options -n and -t of
  1061 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  1062 \isadroptag.
  1063 
  1064 Several document versions may be produced at the same time via isatool
  1065 usedir (the generated index.html will link all of them).  Typical
  1066 specifications include ''-V document=theory,proof,ML'' to present
  1067 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  1068 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  1069 these parts without any formal replacement text.  The Isabelle site
  1070 default settings produce ''document'' and ''outline'' versions as
  1071 specified above.
  1072 
  1073 * Several new antiquotations:
  1074 
  1075   @{term_type term} prints a term with its type annotated;
  1076 
  1077   @{typeof term} prints the type of a term;
  1078 
  1079   @{const const} is the same as @{term const}, but checks that the
  1080   argument is a known logical constant;
  1081 
  1082   @{term_style style term} and @{thm_style style thm} print a term or
  1083   theorem applying a "style" to it
  1084 
  1085   @{ML text}
  1086 
  1087 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  1088 definitions, equations, inequations etc., 'concl' printing only the
  1089 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  1090 to print the specified premise.  TermStyle.add_style provides an ML
  1091 interface for introducing further styles.  See also the "LaTeX Sugar"
  1092 document practical applications.  The ML antiquotation prints
  1093 type-checked ML expressions verbatim.
  1094 
  1095 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  1096 and 'text' support optional locale specification '(in loc)', which
  1097 specifies the default context for interpreting antiquotations.  For
  1098 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  1099 
  1100 * Option 'locale=NAME' of antiquotations specifies an alternative
  1101 context interpreting the subsequent argument.  For example: @{thm
  1102 [locale=lattice] inf_assoc}.
  1103 
  1104 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  1105 a proof context.
  1106 
  1107 * Proper output of antiquotations for theory commands involving a
  1108 proof context (such as 'locale' or 'theorem (in loc) ...').
  1109 
  1110 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  1111 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  1112 
  1113 * isatool usedir: new option -C (default true) controls whether option
  1114 -D should include a copy of the original document directory; -C false
  1115 prevents unwanted effects such as copying of administrative CVS data.
  1116 
  1117 
  1118 *** Pure ***
  1119 
  1120 * Considerably improved version of 'constdefs' command.  Now performs
  1121 automatic type-inference of declared constants; additional support for
  1122 local structure declarations (cf. locales and HOL records), see also
  1123 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  1124 sequential dependencies of definitions within a single 'constdefs'
  1125 section; moreover, the declared name needs to be an identifier.  If
  1126 all fails, consider to fall back on 'consts' and 'defs' separately.
  1127 
  1128 * Improved indexed syntax and implicit structures.  First of all,
  1129 indexed syntax provides a notational device for subscripted
  1130 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  1131 expressions.  Secondly, in a local context with structure
  1132 declarations, number indexes \<^sub>n or the empty index (default
  1133 number 1) refer to a certain fixed variable implicitly; option
  1134 show_structs controls printing of implicit structures.  Typical
  1135 applications of these concepts involve record types and locales.
  1136 
  1137 * New command 'no_syntax' removes grammar declarations (and
  1138 translations) resulting from the given syntax specification, which is
  1139 interpreted in the same manner as for the 'syntax' command.
  1140 
  1141 * 'Advanced' translation functions (parse_translation etc.) may depend
  1142 on the signature of the theory context being presently used for
  1143 parsing/printing, see also isar-ref manual.
  1144 
  1145 * Improved 'oracle' command provides a type-safe interface to turn an
  1146 ML expression of type theory -> T -> term into a primitive rule of
  1147 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  1148 is already included here); see also FOL/ex/IffExample.thy;
  1149 INCOMPATIBILITY.
  1150 
  1151 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  1152 before); "cI" is no longer bound, use "c.intro" instead.
  1153 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  1154 axclasses vs. locales.
  1155 
  1156 * Improved internal renaming of symbolic identifiers -- attach primes
  1157 instead of base 26 numbers.
  1158 
  1159 * New flag show_question_marks controls printing of leading question
  1160 marks in schematic variable names.
  1161 
  1162 * In schematic variable names, *any* symbol following \<^isub> or
  1163 \<^isup> is now treated as part of the base name.  For example, the
  1164 following works without printing of awkward ".0" indexes:
  1165 
  1166   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  1167     by simp
  1168 
  1169 * Inner syntax includes (*(*nested*) comments*).
  1170 
  1171 * Pretty printer now supports unbreakable blocks, specified in mixfix
  1172 annotations as "(00...)".
  1173 
  1174 * Clear separation of logical types and nonterminals, where the latter
  1175 may only occur in 'syntax' specifications or type abbreviations.
  1176 Before that distinction was only partially implemented via type class
  1177 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  1178 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  1179 exotic syntax specifications may require further adaption
  1180 (e.g. Cube/Cube.thy).
  1181 
  1182 * Removed obsolete type class "logic", use the top sort {} instead.
  1183 Note that non-logical types should be declared as 'nonterminals'
  1184 rather than 'types'.  INCOMPATIBILITY for new object-logic
  1185 specifications.
  1186 
  1187 * Attributes 'induct' and 'cases': type or set names may now be
  1188 locally fixed variables as well.
  1189 
  1190 * Simplifier: can now control the depth to which conditional rewriting
  1191 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  1192 Limit.
  1193 
  1194 * Simplifier: simplification procedures may now take the current
  1195 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  1196 interface), which is very useful for calling the Simplifier
  1197 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  1198 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  1199 low-level mk_simproc no longer applies Logic.varify internally, to
  1200 allow for use in a context of fixed variables.
  1201 
  1202 * thin_tac now works even if the assumption being deleted contains !!
  1203 or ==>.  More generally, erule now works even if the major premise of
  1204 the elimination rule contains !! or ==>.
  1205 
  1206 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  1207 
  1208 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  1209 from Pure, which contains all common declarations already.  Both
  1210 theories are defined via plain Isabelle/Isar .thy files.
  1211 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  1212 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  1213 use isatool fixcpure to adapt your theory and ML sources.
  1214 
  1215 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  1216 selections of theorems in named facts via index ranges.
  1217 
  1218 * 'print_theorems': in theory mode, really print the difference
  1219 wrt. the last state (works for interactive theory development only),
  1220 in proof mode print all local facts (cf. 'print_facts');
  1221 
  1222 * 'hide': option '(open)' hides only base names.
  1223 
  1224 * More efficient treatment of intermediate checkpoints in interactive
  1225 theory development.
  1226 
  1227 * Code generator is now invoked via code_module (incremental code
  1228 generation) and code_library (modular code generation, ML structures
  1229 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  1230 must be quoted when used as identifiers.
  1231 
  1232 * New 'value' command for reading, evaluating and printing terms using
  1233 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  1234 quoted when used as identifier.
  1235 
  1236 
  1237 *** Locales ***
  1238 
  1239 * New commands for the interpretation of locale expressions in
  1240 theories (1), locales (2) and proof contexts (3).  These generate
  1241 proof obligations from the expression specification.  After the
  1242 obligations have been discharged, theorems of the expression are added
  1243 to the theory, target locale or proof context.  The synopsis of the
  1244 commands is a follows:
  1245 
  1246   (1) interpretation expr inst
  1247   (2) interpretation target < expr
  1248   (3) interpret expr inst
  1249 
  1250 Interpretation in theories and proof contexts require a parameter
  1251 instantiation of terms from the current context.  This is applied to
  1252 specifications and theorems of the interpreted expression.
  1253 Interpretation in locales only permits parameter renaming through the
  1254 locale expression.  Interpretation is smart in that interpretations
  1255 that are active already do not occur in proof obligations, neither are
  1256 instantiated theorems stored in duplicate.  Use 'print_interps' to
  1257 inspect active interpretations of a particular locale.  For details,
  1258 see the Isar Reference manual.  Examples can be found in
  1259 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  1260 
  1261 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  1262 'interpret' instead.
  1263 
  1264 * New context element 'constrains' for adding type constraints to
  1265 parameters.
  1266 
  1267 * Context expressions: renaming of parameters with syntax
  1268 redeclaration.
  1269 
  1270 * Locale declaration: 'includes' disallowed.
  1271 
  1272 * Proper static binding of attribute syntax -- i.e. types / terms /
  1273 facts mentioned as arguments are always those of the locale definition
  1274 context, independently of the context of later invocations.  Moreover,
  1275 locale operations (renaming and type / term instantiation) are applied
  1276 to attribute arguments as expected.
  1277 
  1278 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  1279 actual attributes; rare situations may require Attrib.attribute to
  1280 embed those attributes into Attrib.src that lack concrete syntax.
  1281 Attribute implementations need to cooperate properly with the static
  1282 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  1283 Attrib.XXX_thm etc. already do the right thing without further
  1284 intervention.  Only unusual applications -- such as "where" or "of"
  1285 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  1286 on the context and the facts involved -- may have to assign parsed
  1287 values to argument tokens explicitly.
  1288 
  1289 * Changed parameter management in theorem generation for long goal
  1290 statements with 'includes'.  INCOMPATIBILITY: produces a different
  1291 theorem statement in rare situations.
  1292 
  1293 * Locale inspection command 'print_locale' omits notes elements.  Use
  1294 'print_locale!' to have them included in the output.
  1295 
  1296 
  1297 *** Provers ***
  1298 
  1299 * Provers/hypsubst.ML: improved version of the subst method, for
  1300 single-step rewriting: it now works in bound variable contexts. New is
  1301 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  1302 rewrite a different subterm than the original subst method, which is
  1303 still available as 'simplesubst'.
  1304 
  1305 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  1306 and quasi orders.
  1307 
  1308 * Provers/trancl.ML: new transitivity reasoner for transitive and
  1309 reflexive-transitive closure of relations.
  1310 
  1311 * Provers/blast.ML: new reference depth_limit to make blast's depth
  1312 limit (previously hard-coded with a value of 20) user-definable.
  1313 
  1314 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  1315 is peformed already.  Object-logics merely need to finish their
  1316 initial simpset configuration as before.  INCOMPATIBILITY.
  1317 
  1318 
  1319 *** HOL ***
  1320 
  1321 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  1322 
  1323   syntax (epsilon)
  1324     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  1325 
  1326 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  1327 and x-symbol; use option '-m epsilon' to get it actually printed.
  1328 Moreover, the mathematically important symbolic identifier \<epsilon>
  1329 becomes available as variable, constant etc.  INCOMPATIBILITY,
  1330 
  1331 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  1332 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  1333 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  1334 support corresponding Isar calculations.
  1335 
  1336 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  1337 instead of ":".
  1338 
  1339 * theory SetInterval: changed the syntax for open intervals:
  1340 
  1341   Old       New
  1342   {..n(}    {..<n}
  1343   {)n..}    {n<..}
  1344   {m..n(}   {m..<n}
  1345   {)m..n}   {m<..n}
  1346   {)m..n(}  {m<..<n}
  1347 
  1348 The old syntax is still supported but will disappear in the next
  1349 release.  For conversion use the following Emacs search and replace
  1350 patterns (these are not perfect but work quite well):
  1351 
  1352   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  1353   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  1354 
  1355 * Theory Commutative_Ring (in Library): method comm_ring for proving
  1356 equalities in commutative rings; method 'algebra' provides a generic
  1357 interface.
  1358 
  1359 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  1360 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  1361 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  1362 be a tuple pattern.
  1363 
  1364 Some new syntax forms are available:
  1365 
  1366   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  1367   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  1368   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  1369   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  1370 
  1371 The latter form "\<Sum>x < k. e" used to be based on a separate
  1372 function "Summation", which has been discontinued.
  1373 
  1374 * theory Finite_Set: in structured induction proofs, the insert case
  1375 is now 'case (insert x F)' instead of the old counterintuitive 'case
  1376 (insert F x)'.
  1377 
  1378 * The 'refute' command has been extended to support a much larger
  1379 fragment of HOL, including axiomatic type classes, constdefs and
  1380 typedefs, inductive datatypes and recursion.
  1381 
  1382 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  1383 Requires zChaff with proof generation to be installed.  See
  1384 HOL/ex/SAT_Examples.thy for examples.
  1385 
  1386 * Datatype induction via method 'induct' now preserves the name of the
  1387 induction variable. For example, when proving P(xs::'a list) by
  1388 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  1389 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  1390 in unstructured proof scripts.
  1391 
  1392 * Reworked implementation of records.  Improved scalability for
  1393 records with many fields, avoiding performance problems for type
  1394 inference. Records are no longer composed of nested field types, but
  1395 of nested extension types. Therefore the record type only grows linear
  1396 in the number of extensions and not in the number of fields.  The
  1397 top-level (users) view on records is preserved.  Potential
  1398 INCOMPATIBILITY only in strange cases, where the theory depends on the
  1399 old record representation. The type generated for a record is called
  1400 <record_name>_ext_type.
  1401 
  1402 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  1403 proofs triggered by a record definition or a simproc (if
  1404 quick_and_dirty is enabled).  Definitions of large records can take
  1405 quite long.
  1406 
  1407 New simproc record_upd_simproc for simplification of multiple record
  1408 updates enabled by default.  Moreover, trivial updates are also
  1409 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  1410 occasionally, since simplification is more powerful by default.
  1411 
  1412 * typedef: proper support for polymorphic sets, which contain extra
  1413 type-variables in the term.
  1414 
  1415 * Simplifier: automatically reasons about transitivity chains
  1416 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  1417 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  1418 old proofs break occasionally as simplification may now solve more
  1419 goals than previously.
  1420 
  1421 * Simplifier: converts x <= y into x = y if assumption y <= x is
  1422 present.  Works for all partial orders (class "order"), in particular
  1423 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  1424 just like y <= x.
  1425 
  1426 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  1427 bound variable or a constant then the let is unfolded.  Otherwise
  1428 first a is simplified to b, and then f b is simplified to g. If
  1429 possible we abstract b from g arriving at "let x = b in h x",
  1430 otherwise we unfold the let and arrive at g.  The simproc can be
  1431 enabled/disabled by the reference use_let_simproc.  Potential
  1432 INCOMPATIBILITY since simplification is more powerful by default.
  1433 
  1434 * Classical reasoning: the meson method now accepts theorems as arguments.
  1435 
  1436 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  1437 jobs to provide advice on the provability of subgoals.
  1438 
  1439 * Theory OrderedGroup and Ring_and_Field: various additions and
  1440 improvements to faciliate calculations involving equalities and
  1441 inequalities.
  1442 
  1443 The following theorems have been eliminated or modified
  1444 (INCOMPATIBILITY):
  1445 
  1446   abs_eq             now named abs_of_nonneg
  1447   abs_of_ge_0        now named abs_of_nonneg
  1448   abs_minus_eq       now named abs_of_nonpos
  1449   imp_abs_id         now named abs_of_nonneg
  1450   imp_abs_neg_id     now named abs_of_nonpos
  1451   mult_pos           now named mult_pos_pos
  1452   mult_pos_le        now named mult_nonneg_nonneg
  1453   mult_pos_neg_le    now named mult_nonneg_nonpos
  1454   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  1455   mult_neg           now named mult_neg_neg
  1456   mult_neg_le        now named mult_nonpos_nonpos
  1457 
  1458 * Theory Parity: added rules for simplifying exponents.
  1459 
  1460 * Theory List:
  1461 
  1462 The following theorems have been eliminated or modified
  1463 (INCOMPATIBILITY):
  1464 
  1465   list_all_Nil       now named list_all.simps(1)
  1466   list_all_Cons      now named list_all.simps(2)
  1467   list_all_conv      now named list_all_iff
  1468   set_mem_eq         now named mem_iff
  1469 
  1470 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  1471 asymptotic "big O" calculations.  See the notes in BigO.thy.
  1472 
  1473 
  1474 *** HOL-Complex ***
  1475 
  1476 * Theory RealDef: better support for embedding natural numbers and
  1477 integers in the reals.
  1478 
  1479 The following theorems have been eliminated or modified
  1480 (INCOMPATIBILITY):
  1481 
  1482   exp_ge_add_one_self  now requires no hypotheses
  1483   real_of_int_add      reversed direction of equality (use [symmetric])
  1484   real_of_int_minus    reversed direction of equality (use [symmetric])
  1485   real_of_int_diff     reversed direction of equality (use [symmetric])
  1486   real_of_int_mult     reversed direction of equality (use [symmetric])
  1487 
  1488 * Theory RComplete: expanded support for floor and ceiling functions.
  1489 
  1490 * Theory Ln is new, with properties of the natural logarithm
  1491 
  1492 * Hyperreal: There is a new type constructor "star" for making
  1493 nonstandard types.  The old type names are now type synonyms:
  1494 
  1495   hypreal = real star
  1496   hypnat = nat star
  1497   hcomplex = complex star
  1498 
  1499 * Hyperreal: Many groups of similarly-defined constants have been
  1500 replaced by polymorphic versions (INCOMPATIBILITY):
  1501 
  1502   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  1503 
  1504   starset      <-- starsetNat, starsetC
  1505   *s*          <-- *sNat*, *sc*
  1506   starset_n    <-- starsetNat_n, starsetC_n
  1507   *sn*         <-- *sNatn*, *scn*
  1508   InternalSets <-- InternalNatSets, InternalCSets
  1509 
  1510   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  1511   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  1512   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  1513   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  1514   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  1515 
  1516 * Hyperreal: Many type-specific theorems have been removed in favor of
  1517 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  1518 
  1519   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  1520   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  1521   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  1522   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  1523   right_minus <-- hypreal_add_minus
  1524   left_minus <-- {hypreal,hcomplex}_add_minus_left
  1525   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  1526   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  1527   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  1528   mult_1_right <-- hcomplex_mult_one_right
  1529   mult_zero_left <-- hcomplex_mult_zero_left
  1530   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  1531   right_distrib <-- hypnat_add_mult_distrib2
  1532   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  1533   right_inverse <-- hypreal_mult_inverse
  1534   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  1535   order_refl <-- {hypreal,hypnat}_le_refl
  1536   order_trans <-- {hypreal,hypnat}_le_trans
  1537   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  1538   order_less_le <-- {hypreal,hypnat}_less_le
  1539   linorder_linear <-- {hypreal,hypnat}_le_linear
  1540   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  1541   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  1542   add_nonneg_nonneg <-- hypreal_le_add_order
  1543 
  1544 * Hyperreal: Separate theorems having to do with type-specific
  1545 versions of constants have been merged into theorems that apply to the
  1546 new polymorphic constants (INCOMPATIBILITY):
  1547 
  1548   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  1549   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  1550   STAR_Un <-- {STAR,NatStar,STARC}_Un
  1551   STAR_Int <-- {STAR,NatStar,STARC}_Int
  1552   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  1553   STAR_subset <-- {STAR,NatStar,STARC}_subset
  1554   STAR_mem <-- {STAR,NatStar,STARC}_mem
  1555   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  1556   STAR_diff <-- {STAR,STARC}_diff
  1557   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  1558     STARC_hcomplex_of_complex}_image_subset
  1559   starset_n_Un <-- starset{Nat,C}_n_Un
  1560   starset_n_Int <-- starset{Nat,C}_n_Int
  1561   starset_n_Compl <-- starset{Nat,C}_n_Compl
  1562   starset_n_diff <-- starset{Nat,C}_n_diff
  1563   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  1564   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  1565   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  1566   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  1567   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  1568   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  1569   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  1570   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  1571   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  1572   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  1573   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  1574   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  1575   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  1576   starfun_diff <-- starfun{C,RC,CR}_diff
  1577   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  1578   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  1579   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  1580   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  1581   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  1582   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  1583   starfun_Id <-- starfunC_Id
  1584   starfun_approx <-- starfun{Nat,CR}_approx
  1585   starfun_capprox <-- starfun{C,RC}_capprox
  1586   starfun_abs <-- starfunNat_rabs
  1587   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  1588   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  1589   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  1590   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  1591   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  1592   starfun_add_approx <-- starfunCR_add_approx
  1593   starfun_inverse_inverse <-- starfunC_inverse_inverse
  1594   starfun_divide <-- starfun{C,CR,RC}_divide
  1595   starfun_n <-- starfun{Nat,C}_n
  1596   starfun_n_mult <-- starfun{Nat,C}_n_mult
  1597   starfun_n_add <-- starfun{Nat,C}_n_add
  1598   starfun_n_add_minus <-- starfunNat_n_add_minus
  1599   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  1600   starfun_n_minus <-- starfun{Nat,C}_n_minus
  1601   starfun_n_eq <-- starfun{Nat,C}_n_eq
  1602 
  1603   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  1604   star_n_minus <-- {hypreal,hcomplex}_minus
  1605   star_n_diff <-- {hypreal,hcomplex}_diff
  1606   star_n_mult <-- {hypreal,hcomplex}_mult
  1607   star_n_inverse <-- {hypreal,hcomplex}_inverse
  1608   star_n_le <-- {hypreal,hypnat}_le
  1609   star_n_less <-- {hypreal,hypnat}_less
  1610   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  1611   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  1612   star_n_abs <-- hypreal_hrabs
  1613   star_n_divide <-- hcomplex_divide
  1614 
  1615   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  1616   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  1617   star_of_diff <-- hypreal_of_real_diff
  1618   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  1619   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  1620   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  1621   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  1622   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  1623   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  1624   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  1625   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  1626   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  1627   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  1628   star_of_number_of <-- {hypreal,hcomplex}_number_of
  1629   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  1630   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  1631   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  1632   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  1633   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  1634   star_of_power <-- hypreal_of_real_power
  1635   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  1636 
  1637 * Hyperreal: new method "transfer" that implements the transfer
  1638 principle of nonstandard analysis. With a subgoal that mentions
  1639 nonstandard types like "'a star", the command "apply transfer"
  1640 replaces it with an equivalent one that mentions only standard types.
  1641 To be successful, all free variables must have standard types; non-
  1642 standard variables must have explicit universal quantifiers.
  1643 
  1644 * Hyperreal: A theory of Taylor series.
  1645 
  1646 
  1647 *** HOLCF ***
  1648 
  1649 * Discontinued special version of 'constdefs' (which used to support
  1650 continuous functions) in favor of the general Pure one with full
  1651 type-inference.
  1652 
  1653 * New simplification procedure for solving continuity conditions; it
  1654 is much faster on terms with many nested lambda abstractions (cubic
  1655 instead of exponential time).
  1656 
  1657 * New syntax for domain package: selector names are now optional.
  1658 Parentheses should be omitted unless argument is lazy, for example:
  1659 
  1660   domain 'a stream = cons "'a" (lazy "'a stream")
  1661 
  1662 * New command 'fixrec' for defining recursive functions with pattern
  1663 matching; defining multiple functions with mutual recursion is also
  1664 supported.  Patterns may include the constants cpair, spair, up, sinl,
  1665 sinr, or any data constructor defined by the domain package. The given
  1666 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  1667 syntax and examples.
  1668 
  1669 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  1670 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  1671 but the proof obligation additionally includes an admissibility
  1672 requirement. The packages generate instances of class cpo or pcpo,
  1673 with continuity and strictness theorems for Rep and Abs.
  1674 
  1675 * HOLCF: Many theorems have been renamed according to a more standard naming
  1676 scheme (INCOMPATIBILITY):
  1677 
  1678   foo_inject:  "foo$x = foo$y ==> x = y"
  1679   foo_eq:      "(foo$x = foo$y) = (x = y)"
  1680   foo_less:    "(foo$x << foo$y) = (x << y)"
  1681   foo_strict:  "foo$UU = UU"
  1682   foo_defined: "... ==> foo$x ~= UU"
  1683   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  1684 
  1685 
  1686 *** ZF ***
  1687 
  1688 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  1689 including the First Isomorphism Theorem (on quotienting by the kernel
  1690 of a homomorphism).
  1691 
  1692 * ZF/Simplifier: install second copy of type solver that actually
  1693 makes use of TC rules declared to Isar proof contexts (or locales);
  1694 the old version is still required for ML proof scripts.
  1695 
  1696 
  1697 *** Cube ***
  1698 
  1699 * Converted to Isar theory format; use locales instead of axiomatic
  1700 theories.
  1701 
  1702 
  1703 *** ML ***
  1704 
  1705 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  1706 for ||>, ||>>, |>>,
  1707 
  1708 * Pure/library.ML no longer defines its own option datatype, but uses
  1709 that of the SML basis, which has constructors NONE and SOME instead of
  1710 None and Some, as well as exception Option.Option instead of OPTION.
  1711 The functions the, if_none, is_some, is_none have been adapted
  1712 accordingly, while Option.map replaces apsome.
  1713 
  1714 * Pure/library.ML: the exception LIST has been given up in favour of
  1715 the standard exceptions Empty and Subscript, as well as
  1716 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  1717 superceded by the standard hd and tl functions etc.
  1718 
  1719 A number of basic list functions are no longer exported to the ML
  1720 toplevel, as they are variants of predefined functions.  The following
  1721 suggests how one can translate existing code:
  1722 
  1723     rev_append xs ys = List.revAppend (xs, ys)
  1724     nth_elem (i, xs) = List.nth (xs, i)
  1725     last_elem xs = List.last xs
  1726     flat xss = List.concat xss
  1727     seq fs = List.app fs
  1728     partition P xs = List.partition P xs
  1729     mapfilter f xs = List.mapPartial f xs
  1730 
  1731 * Pure/library.ML: several combinators for linear functional
  1732 transformations, notably reverse application and composition:
  1733 
  1734   x |> f                f #> g
  1735   (x, y) |-> f          f #-> g
  1736 
  1737 * Pure/library.ML: introduced/changed precedence of infix operators:
  1738 
  1739   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  1740   infix 2 ?;
  1741   infix 3 o oo ooo oooo;
  1742   infix 4 ~~ upto downto;
  1743 
  1744 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  1745 infix operators.
  1746 
  1747 * Pure/library.ML: natural list combinators fold, fold_rev, and
  1748 fold_map support linear functional transformations and nesting.  For
  1749 example:
  1750 
  1751   fold f [x1, ..., xN] y =
  1752     y |> f x1 |> ... |> f xN
  1753 
  1754   (fold o fold) f [xs1, ..., xsN] y =
  1755     y |> fold f xs1 |> ... |> fold f xsN
  1756 
  1757   fold f [x1, ..., xN] =
  1758     f x1 #> ... #> f xN
  1759 
  1760   (fold o fold) f [xs1, ..., xsN] =
  1761     fold f xs1 #> ... #> fold f xsN
  1762 
  1763 * Pure/library.ML: the following selectors on type 'a option are
  1764 available:
  1765 
  1766   the:               'a option -> 'a  (*partial*)
  1767   these:             'a option -> 'a  where 'a = 'b list
  1768   the_default: 'a -> 'a option -> 'a
  1769   the_list:          'a option -> 'a list
  1770 
  1771 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  1772 basic operations for association lists, following natural argument
  1773 order; moreover the explicit equality predicate passed here avoids
  1774 potentially expensive polymorphic runtime equality checks.
  1775 The old functions may be expressed as follows:
  1776 
  1777   assoc = uncurry (AList.lookup (op =))
  1778   assocs = these oo AList.lookup (op =)
  1779   overwrite = uncurry (AList.update (op =)) o swap
  1780 
  1781 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  1782 
  1783   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  1784   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  1785 
  1786 replacing make_keylist and keyfilter (occassionally used)
  1787 Naive rewrites:
  1788 
  1789   make_keylist = AList.make
  1790   keyfilter = AList.find (op =)
  1791 
  1792 * eq_fst and eq_snd now take explicit equality parameter, thus
  1793   avoiding eqtypes. Naive rewrites:
  1794 
  1795     eq_fst = eq_fst (op =)
  1796     eq_snd = eq_snd (op =)
  1797 
  1798 * Removed deprecated apl and apr (rarely used).
  1799   Naive rewrites:
  1800 
  1801     apl (n, op) =>>= curry op n
  1802     apr (op, m) =>>= fn n => op (n, m)
  1803 
  1804 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  1805 provides a reasonably efficient light-weight implementation of sets as
  1806 lists.
  1807 
  1808 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  1809 few new operations; existing lookup and update are now curried to
  1810 follow natural argument order (for use with fold etc.);
  1811 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  1812 
  1813 * Pure/General: output via the Isabelle channels of
  1814 writeln/warning/error etc. is now passed through Output.output, with a
  1815 hook for arbitrary transformations depending on the print_mode
  1816 (cf. Output.add_mode -- the first active mode that provides a output
  1817 function wins).  Already formatted output may be embedded into further
  1818 text via Output.raw; the result of Pretty.string_of/str_of and derived
  1819 functions (string_of_term/cterm/thm etc.) is already marked raw to
  1820 accommodate easy composition of diagnostic messages etc.  Programmers
  1821 rarely need to care about Output.output or Output.raw at all, with
  1822 some notable exceptions: Output.output is required when bypassing the
  1823 standard channels (writeln etc.), or in token translations to produce
  1824 properly formatted results; Output.raw is required when capturing
  1825 already output material that will eventually be presented to the user
  1826 a second time.  For the default print mode, both Output.output and
  1827 Output.raw have no effect.
  1828 
  1829 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  1830 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  1831 cumulative results are displayed at the end of a batch session.
  1832 
  1833 * Pure/General: File.sysify_path and File.quote_sysify path have been
  1834 replaced by File.platform_path and File.shell_path (with appropriate
  1835 hooks).  This provides a clean interface for unusual systems where the
  1836 internal and external process view of file names are different.
  1837 
  1838 * Pure: more efficient orders for basic syntactic entities: added
  1839 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  1840 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  1841 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  1842 orders now -- potential INCOMPATIBILITY for code that depends on a
  1843 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  1844 Library.sort_strings on result).
  1845 
  1846 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  1847 fold_types traverse types/terms from left to right, observing natural
  1848 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  1849 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  1850 
  1851 * Pure: name spaces have been refined, with significant changes of the
  1852 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  1853 to extern(_table).  The plain name entry path is superceded by a
  1854 general 'naming' context, which also includes the 'policy' to produce
  1855 a fully qualified name and external accesses of a fully qualified
  1856 name; NameSpace.extend is superceded by context dependent
  1857 Sign.declare_name.  Several theory and proof context operations modify
  1858 the naming context.  Especially note Theory.restore_naming and
  1859 ProofContext.restore_naming to get back to a sane state; note that
  1860 Theory.add_path is no longer sufficient to recover from
  1861 Theory.absolute_path in particular.
  1862 
  1863 * Pure: new flags short_names (default false) and unique_names
  1864 (default true) for controlling output of qualified names.  If
  1865 short_names is set, names are printed unqualified.  If unique_names is
  1866 reset, the name prefix is reduced to the minimum required to achieve
  1867 the original result when interning again, even if there is an overlap
  1868 with earlier declarations.
  1869 
  1870 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  1871 now 'extend', and 'merge' gets an additional Pretty.pp argument
  1872 (useful for printing error messages).  INCOMPATIBILITY.
  1873 
  1874 * Pure: major reorganization of the theory context.  Type Sign.sg and
  1875 Theory.theory are now identified, referring to the universal
  1876 Context.theory (see Pure/context.ML).  Actual signature and theory
  1877 content is managed as theory data.  The old code and interfaces were
  1878 spread over many files and structures; the new arrangement introduces
  1879 considerable INCOMPATIBILITY to gain more clarity:
  1880 
  1881   Context -- theory management operations (name, identity, inclusion,
  1882     parents, ancestors, merge, etc.), plus generic theory data;
  1883 
  1884   Sign -- logical signature and syntax operations (declaring consts,
  1885     types, etc.), plus certify/read for common entities;
  1886 
  1887   Theory -- logical theory operations (stating axioms, definitions,
  1888     oracles), plus a copy of logical signature operations (consts,
  1889     types, etc.); also a few basic management operations (Theory.copy,
  1890     Theory.merge, etc.)
  1891 
  1892 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  1893 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  1894 for convenience -- they merely return the theory.
  1895 
  1896 * Pure: type Type.tsig is superceded by theory in most interfaces.
  1897 
  1898 * Pure: the Isar proof context type is already defined early in Pure
  1899 as Context.proof (note that ProofContext.context and Proof.context are
  1900 aliases, where the latter is the preferred name).  This enables other
  1901 Isabelle components to refer to that type even before Isar is present.
  1902 
  1903 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  1904 typeK, constK, axiomK, oracleK), but provide explicit operations for
  1905 any of these kinds.  For example, Sign.intern typeK is now
  1906 Sign.intern_type, Theory.hide_space Sign.typeK is now
  1907 Theory.hide_types.  Also note that former
  1908 Theory.hide_classes/types/consts are now
  1909 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  1910 internalize their arguments!  INCOMPATIBILITY.
  1911 
  1912 * Pure: get_thm interface (of PureThy and ProofContext) expects
  1913 datatype thmref (with constructors Name and NameSelection) instead of
  1914 plain string -- INCOMPATIBILITY;
  1915 
  1916 * Pure: cases produced by proof methods specify options, where NONE
  1917 means to remove case bindings -- INCOMPATIBILITY in
  1918 (RAW_)METHOD_CASES.
  1919 
  1920 * Pure: the following operations retrieve axioms or theorems from a
  1921 theory node or theory hierarchy, respectively:
  1922 
  1923   Theory.axioms_of: theory -> (string * term) list
  1924   Theory.all_axioms_of: theory -> (string * term) list
  1925   PureThy.thms_of: theory -> (string * thm) list
  1926   PureThy.all_thms_of: theory -> (string * thm) list
  1927 
  1928 * Pure: print_tac now outputs the goal through the trace channel.
  1929 
  1930 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  1931 Reference Toplevel.debug (default false) controls detailed printing
  1932 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  1933 controls execution profiling -- set to 1 for time and 2 for space
  1934 (both increase the runtime).
  1935 
  1936 * Isar session: The initial use of ROOT.ML is now always timed,
  1937 i.e. the log will show the actual process times, in contrast to the
  1938 elapsed wall-clock time that the outer shell wrapper produces.
  1939 
  1940 * Simplifier: improved handling of bound variables (nameless
  1941 representation, avoid allocating new strings).  Simprocs that invoke
  1942 the Simplifier recursively should use Simplifier.inherit_bounds to
  1943 avoid local name clashes.  Failure to do so produces warnings
  1944 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  1945 for further details.
  1946 
  1947 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  1948 bindings for all theorems stored within a given theory; this may help
  1949 in porting non-Isar theories to Isar ones, while keeping ML proof
  1950 scripts for the time being.
  1951 
  1952 * ML operator HTML.with_charset specifies the charset begin used for
  1953 generated HTML files.  For example:
  1954 
  1955   HTML.with_charset "utf-8" use_thy "Hebrew";
  1956   HTML.with_charset "utf-8" use_thy "Chinese";
  1957 
  1958 
  1959 *** System ***
  1960 
  1961 * Allow symlinks to all proper Isabelle executables (Isabelle,
  1962 isabelle, isatool etc.).
  1963 
  1964 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  1965 isatool doc, isatool mkdir, display_drafts etc.).
  1966 
  1967 * isatool usedir: option -f allows specification of the ML file to be
  1968 used by Isabelle; default is ROOT.ML.
  1969 
  1970 * New isatool version outputs the version identifier of the Isabelle
  1971 distribution being used.
  1972 
  1973 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  1974 (containing Boolean satisfiability problems) into Isabelle/HOL
  1975 theories.
  1976 
  1977 
  1978 
  1979 New in Isabelle2004 (April 2004)
  1980 --------------------------------
  1981 
  1982 *** General ***
  1983 
  1984 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  1985   Replaces linorder.ML.
  1986 
  1987 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  1988   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  1989   (\<a>...\<z>), are now considered normal letters, and can therefore
  1990   be used anywhere where an ASCII letter (a...zA...Z) has until
  1991   now. COMPATIBILITY: This obviously changes the parsing of some
  1992   terms, especially where a symbol has been used as a binder, say
  1993   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  1994   as an identifier.  Fix it by inserting a space around former
  1995   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  1996   existing theory and ML files.
  1997 
  1998 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  1999 
  2000 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  2001   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  2002   a normal (but invisible) letter. For multiple letter subscripts repeat
  2003   \<^isub> like this: x\<^isub>1\<^isub>2.
  2004 
  2005 * Pure: There are now sub-/superscripts that can span more than one
  2006   character. Text between \<^bsub> and \<^esub> is set in subscript in
  2007   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  2008   superscript. The new control characters are not identifier parts.
  2009 
  2010 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  2011   content of "..." to the latex file instead of \isacntrl... . The "..."
  2012   may consist of any printable characters excluding the end bracket >.
  2013 
  2014 * Pure: Using new Isar command "finalconsts" (or the ML functions
  2015   Theory.add_finals or Theory.add_finals_i) it is now possible to
  2016   declare constants "final", which prevents their being given a definition
  2017   later.  It is useful for constants whose behaviour is fixed axiomatically
  2018   rather than definitionally, such as the meta-logic connectives.
  2019 
  2020 * Pure: 'instance' now handles general arities with general sorts
  2021   (i.e. intersections of classes),
  2022 
  2023 * Presentation: generated HTML now uses a CSS style sheet to make layout
  2024   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  2025   It can be changed to alter the colors/layout of generated pages.
  2026 
  2027 
  2028 *** Isar ***
  2029 
  2030 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  2031   cut_tac, subgoal_tac and thin_tac:
  2032   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  2033     locales are no longer forced to write Isar proof scripts.
  2034     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  2035     emulations.
  2036   - INCOMPATIBILITY: names of variables to be instantiated may no
  2037     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  2038     This is consistent with the instantiation attribute "where".
  2039 
  2040 * Attributes "where" and "of":
  2041   - Now take type variables of instantiated theorem into account when reading
  2042     the instantiation string.  This fixes a bug that caused instantiated
  2043     theorems to have too special types in some circumstances.
  2044   - "where" permits explicit instantiations of type variables.
  2045 
  2046 * Calculation commands "moreover" and "also" no longer interfere with
  2047   current facts ("this"), admitting arbitrary combinations with "then"
  2048   and derived forms.
  2049 
  2050 * Locales:
  2051   - Goal statements involving the context element "includes" no longer
  2052     generate theorems with internal delta predicates (those ending on
  2053     "_axioms") in the premise.
  2054     Resolve particular premise with <locale>.intro to obtain old form.
  2055   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  2056     specification and "includes" elements in goal statement.
  2057   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  2058     [intro?] and [elim?] (respectively) by default.
  2059   - Experimental command for instantiation of locales in proof contexts:
  2060         instantiate <label>[<attrs>]: <loc>
  2061     Instantiates locale <loc> and adds all its theorems to the current context
  2062     taking into account their attributes.  Label and attrs are optional
  2063     modifiers, like in theorem declarations.  If present, names of
  2064     instantiated theorems are qualified with <label>, and the attributes
  2065     <attrs> are applied after any attributes these theorems might have already.
  2066       If the locale has assumptions, a chained fact of the form
  2067     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  2068     are derived.  The command does not support old-style locales declared
  2069     with "locale (open)".
  2070       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  2071 
  2072 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  2073   (Isar) contexts.
  2074 
  2075 
  2076 *** HOL ***
  2077 
  2078 * Proof import: new image HOL4 contains the imported library from
  2079   the HOL4 system with about 2500 theorems. It is imported by
  2080   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  2081   can be used like any other Isabelle image.  See
  2082   HOL/Import/HOL/README for more information.
  2083 
  2084 * Simplifier:
  2085   - Much improved handling of linear and partial orders.
  2086     Reasoners for linear and partial orders are set up for type classes
  2087     "linorder" and "order" respectively, and are added to the default simpset
  2088     as solvers.  This means that the simplifier can build transitivity chains
  2089     to solve goals from the assumptions.
  2090   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  2091     of blast or auto after simplification become unnecessary because the goal
  2092     is solved by simplification already.
  2093 
  2094 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  2095     all proved in axiomatic type classes for semirings, rings and fields.
  2096 
  2097 * Numerics:
  2098   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  2099     now formalized using the Ring_and_Field theory mentioned above.
  2100   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  2101     than before, because now they are set up once in a generic manner.
  2102   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  2103     Look for the general versions in Ring_and_Field (and Power if they concern
  2104     exponentiation).
  2105 
  2106 * Type "rat" of the rational numbers is now available in HOL-Complex.
  2107 
  2108 * Records:
  2109   - Record types are now by default printed with their type abbreviation
  2110     instead of the list of all field types. This can be configured via
  2111     the reference "print_record_type_abbr".
  2112   - Simproc "record_upd_simproc" for simplification of multiple updates added
  2113     (not enabled by default).
  2114   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  2115     EX x. x = sel r to True (not enabled by default).
  2116   - Tactic "record_split_simp_tac" to split and simplify records added.
  2117 
  2118 * 'specification' command added, allowing for definition by
  2119   specification.  There is also an 'ax_specification' command that
  2120   introduces the new constants axiomatically.
  2121 
  2122 * arith(_tac) is now able to generate counterexamples for reals as well.
  2123 
  2124 * HOL-Algebra: new locale "ring" for non-commutative rings.
  2125 
  2126 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  2127   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  2128 
  2129 * HOL-Matrix: a first theory for matrices in HOL with an application of
  2130   matrix theory to linear programming.
  2131 
  2132 * Unions and Intersections:
  2133   The latex output syntax of UN and INT has been changed
  2134   from "\Union x \in A. B" to "\Union_{x \in A} B"
  2135   i.e. the index formulae has become a subscript.
  2136   Similarly for "\Union x. B", and for \Inter instead of \Union.
  2137 
  2138 * Unions and Intersections over Intervals:
  2139   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  2140   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  2141   like in normal math, and corresponding versions for < and for intersection.
  2142 
  2143 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  2144   lexicographic dictonary ordering has been added as "lexord".
  2145 
  2146 * ML: the legacy theory structures Int and List have been removed. They had
  2147   conflicted with ML Basis Library structures having the same names.
  2148 
  2149 * 'refute' command added to search for (finite) countermodels.  Only works
  2150   for a fragment of HOL.  The installation of an external SAT solver is
  2151   highly recommended.  See "HOL/Refute.thy" for details.
  2152 
  2153 * 'quickcheck' command: Allows to find counterexamples by evaluating
  2154   formulae under an assignment of free variables to random values.
  2155   In contrast to 'refute', it can deal with inductive datatypes,
  2156   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  2157   for examples.
  2158 
  2159 
  2160 *** HOLCF ***
  2161 
  2162 * Streams now come with concatenation and are part of the HOLCF image
  2163 
  2164 
  2165 
  2166 New in Isabelle2003 (May 2003)
  2167 ------------------------------
  2168 
  2169 *** General ***
  2170 
  2171 * Provers/simplifier:
  2172 
  2173   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  2174     Assumptions are now subject to complete mutual simplification,
  2175     not just from left to right. The simplifier now preserves
  2176     the order of assumptions.
  2177 
  2178     Potential INCOMPATIBILITY:
  2179 
  2180     -- simp sometimes diverges where the old version did
  2181        not, e.g. invoking simp on the goal
  2182 
  2183         [| P (f x); y = x; f x = f y |] ==> Q
  2184 
  2185        now gives rise to the infinite reduction sequence
  2186 
  2187         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  2188 
  2189        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  2190        kind of problem.
  2191 
  2192     -- Tactics combining classical reasoner and simplification (such as auto)
  2193        are also affected by this change, because many of them rely on
  2194        simp. They may sometimes diverge as well or yield a different numbers
  2195        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  2196        in case of problems. Sometimes subsequent calls to the classical
  2197        reasoner will fail because a preceeding call to the simplifier too
  2198        eagerly simplified the goal, e.g. deleted redundant premises.
  2199 
  2200   - The simplifier trace now shows the names of the applied rewrite rules
  2201 
  2202   - You can limit the number of recursive invocations of the simplifier
  2203     during conditional rewriting (where the simplifie tries to solve the
  2204     conditions before applying the rewrite rule):
  2205     ML "simp_depth_limit := n"
  2206     where n is an integer. Thus you can force termination where previously
  2207     the simplifier would diverge.
  2208 
  2209   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  2210 
  2211   - No longer aborts on failed congruence proof.  Instead, the
  2212     congruence is ignored.
  2213 
  2214 * Pure: New generic framework for extracting programs from constructive
  2215   proofs. See HOL/Extraction.thy for an example instantiation, as well
  2216   as HOL/Extraction for some case studies.
  2217 
  2218 * Pure: The main goal of the proof state is no longer shown by default, only
  2219 the subgoals. This behaviour is controlled by a new flag.
  2220    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  2221 (ML: Proof.show_main_goal).
  2222 
  2223 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  2224 rules whose conclusion matches subgoal 1:
  2225       PG menu: Isabelle/Isar -> Show me -> matching rules
  2226 The rules are ordered by how closely they match the subgoal.
  2227 In particular, rules that solve a subgoal outright are displayed first
  2228 (or rather last, the way they are printed).
  2229 (ML: ProofGeneral.print_intros())
  2230 
  2231 * Pure: New flag trace_unify_fail causes unification to print
  2232 diagnostic information (PG: in trace buffer) when it fails. This is
  2233 useful for figuring out why single step proofs like rule, erule or
  2234 assumption failed.
  2235 
  2236 * Pure: Locale specifications now produce predicate definitions
  2237 according to the body of text (covering assumptions modulo local
  2238 definitions); predicate "loc_axioms" covers newly introduced text,
  2239 while "loc" is cumulative wrt. all included locale expressions; the
  2240 latter view is presented only on export into the global theory
  2241 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  2242 on the old view without predicates;
  2243 
  2244 * Pure: predefined locales "var" and "struct" are useful for sharing
  2245 parameters (as in CASL, for example); just specify something like
  2246 ``var x + var y + struct M'' as import;
  2247 
  2248 * Pure: improved thms_containing: proper indexing of facts instead of
  2249 raw theorems; check validity of results wrt. current name space;
  2250 include local facts of proof configuration (also covers active
  2251 locales), cover fixed variables in index; may use "_" in term
  2252 specification; an optional limit for the number of printed facts may
  2253 be given (the default is 40);
  2254 
  2255 * Pure: disallow duplicate fact bindings within new-style theory files
  2256 (batch-mode only);
  2257 
  2258 * Provers: improved induct method: assumptions introduced by case
  2259 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  2260 the goal statement); "foo" still refers to all facts collectively;
  2261 
  2262 * Provers: the function blast.overloaded has been removed: all constants
  2263 are regarded as potentially overloaded, which improves robustness in exchange
  2264 for slight decrease in efficiency;
  2265 
  2266 * Provers/linorder: New generic prover for transitivity reasoning over
  2267 linear orders.  Note: this prover is not efficient!
  2268 
  2269 * Isar: preview of problems to finish 'show' now produce an error
  2270 rather than just a warning (in interactive mode);
  2271 
  2272 
  2273 *** HOL ***
  2274 
  2275 * arith(_tac)
  2276 
  2277  - Produces a counter example if it cannot prove a goal.
  2278    Note that the counter example may be spurious if the goal is not a formula
  2279    of quantifier-free linear arithmetic.
  2280    In ProofGeneral the counter example appears in the trace buffer.
  2281 
  2282  - Knows about div k and mod k where k is a numeral of type nat or int.
  2283 
  2284  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  2285    linear arithmetic fails. This takes account of quantifiers and divisibility.
  2286    Presburger arithmetic can also be called explicitly via presburger(_tac).
  2287 
  2288 * simp's arithmetic capabilities have been enhanced a bit: it now
  2289 takes ~= in premises into account (by performing a case split);
  2290 
  2291 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  2292 are distributed over a sum of terms;
  2293 
  2294 * New tactic "trans_tac" and method "trans" instantiate
  2295 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  2296 "<=", "<" and "=").
  2297 
  2298 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  2299 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  2300 
  2301 * 'typedef' command has new option "open" to suppress the set
  2302 definition;
  2303 
  2304 * functions Min and Max on finite sets have been introduced (theory
  2305 Finite_Set);
  2306 
  2307 * attribute [symmetric] now works for relations as well; it turns
  2308 (x,y) : R^-1 into (y,x) : R, and vice versa;
  2309 
  2310 * induct over a !!-quantified statement (say !!x1..xn):
  2311   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  2312 
  2313 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  2314 %x. None. Warning: empty_def now refers to the previously hidden definition
  2315 of the empty set.
  2316 
  2317 * Algebra: formalization of classical algebra.  Intended as base for
  2318 any algebraic development in Isabelle.  Currently covers group theory
  2319 (up to Sylow's theorem) and ring theory (Universal Property of
  2320 Univariate Polynomials).  Contributions welcome;
  2321 
  2322 * GroupTheory: deleted, since its material has been moved to Algebra;
  2323 
  2324 * Complex: new directory of the complex numbers with numeric constants,
  2325 nonstandard complex numbers, and some complex analysis, standard and
  2326 nonstandard (Jacques Fleuriot);
  2327 
  2328 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  2329 
  2330 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  2331 Fleuriot);
  2332 
  2333 * Real/HahnBanach: updated and adapted to locales;
  2334 
  2335 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  2336 Gray and Kramer);
  2337 
  2338 * UNITY: added the Meier-Sanders theory of progress sets;
  2339 
  2340 * MicroJava: bytecode verifier and lightweight bytecode verifier
  2341 as abstract algorithms, instantiated to the JVM;
  2342 
  2343 * Bali: Java source language formalization. Type system, operational
  2344 semantics, axiomatic semantics. Supported language features:
  2345 classes, interfaces, objects,virtual methods, static methods,
  2346 static/instance fields, arrays, access modifiers, definite
  2347 assignment, exceptions.
  2348 
  2349 
  2350 *** ZF ***
  2351 
  2352 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  2353 universe, etc.);
  2354 
  2355 * Main ZF: virtually all theories converted to new-style format;
  2356 
  2357 
  2358 *** ML ***
  2359 
  2360 * Pure: Tactic.prove provides sane interface for internal proofs;
  2361 omits the infamous "standard" operation, so this is more appropriate
  2362 than prove_goalw_cterm in many situations (e.g. in simprocs);
  2363 
  2364 * Pure: improved error reporting of simprocs;
  2365 
  2366 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  2367 up simprocs;
  2368 
  2369 
  2370 *** Document preparation ***
  2371 
  2372 * uses \par instead of \\ for line breaks in theory text. This may
  2373 shift some page breaks in large documents. To get the old behaviour
  2374 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  2375 
  2376 * minimized dependencies of isabelle.sty and isabellesym.sty on
  2377 other packages
  2378 
  2379 * \<euro> now needs package babel/greek instead of marvosym (which
  2380 broke \Rightarrow)
  2381 
  2382 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  2383 textcomp package)
  2384 
  2385 
  2386 
  2387 New in Isabelle2002 (March 2002)
  2388 --------------------------------
  2389 
  2390 *** Document preparation ***
  2391 
  2392 * greatly simplified document preparation setup, including more
  2393 graceful interpretation of isatool usedir -i/-d/-D options, and more
  2394 instructive isatool mkdir; users should basically be able to get
  2395 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  2396 users may run a separate document processing stage manually like this:
  2397 "isatool usedir -D output HOL Test && isatool document Test/output";
  2398 
  2399 * theory dependency graph may now be incorporated into documents;
  2400 isatool usedir -g true will produce session_graph.eps/.pdf for use
  2401 with \includegraphics of LaTeX;
  2402 
  2403 * proper spacing of consecutive markup elements, especially text
  2404 blocks after section headings;
  2405 
  2406 * support bold style (for single symbols only), input syntax is like
  2407 this: "\<^bold>\<alpha>" or "\<^bold>A";
  2408 
  2409 * \<bullet> is now output as bold \cdot by default, which looks much
  2410 better in printed text;
  2411 
  2412 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  2413 note that these symbols are currently unavailable in Proof General /
  2414 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  2415 
  2416 * isatool latex no longer depends on changed TEXINPUTS, instead
  2417 isatool document copies the Isabelle style files to the target
  2418 location;
  2419 
  2420 
  2421 *** Isar ***
  2422 
  2423 * Pure/Provers: improved proof by cases and induction;
  2424   - 'case' command admits impromptu naming of parameters (such as
  2425     "case (Suc n)");
  2426   - 'induct' method divinates rule instantiation from the inductive
  2427     claim; no longer requires excessive ?P bindings for proper
  2428     instantiation of cases;
  2429   - 'induct' method properly enumerates all possibilities of set/type
  2430     rules; as a consequence facts may be also passed through *type*
  2431     rules without further ado;
  2432   - 'induct' method now derives symbolic cases from the *rulified*
  2433     rule (before it used to rulify cases stemming from the internal
  2434     atomized version); this means that the context of a non-atomic
  2435     statement becomes is included in the hypothesis, avoiding the
  2436     slightly cumbersome show "PROP ?case" form;
  2437   - 'induct' may now use elim-style induction rules without chaining
  2438     facts, using ``missing'' premises from the goal state; this allows
  2439     rules stemming from inductive sets to be applied in unstructured
  2440     scripts, while still benefitting from proper handling of non-atomic
  2441     statements; NB: major inductive premises need to be put first, all
  2442     the rest of the goal is passed through the induction;
  2443   - 'induct' proper support for mutual induction involving non-atomic
  2444     rule statements (uses the new concept of simultaneous goals, see
  2445     below);
  2446   - append all possible rule selections, but only use the first
  2447     success (no backtracking);
  2448   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  2449   - undeclared rule case names default to numbers 1, 2, 3, ...;
  2450   - added 'print_induct_rules' (covered by help item in recent Proof
  2451     General versions);
  2452   - moved induct/cases attributes to Pure, methods to Provers;
  2453   - generic method setup instantiated for FOL and HOL;
  2454 
  2455 * Pure: support multiple simultaneous goal statements, for example
  2456 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  2457 meta-level mechanism, this acts as if several individual goals had
  2458 been stated separately; in particular common proof methods need to be
  2459 repeated in order to cover all claims; note that a single elimination
  2460 step is *not* sufficient to establish the two conjunctions, so this
  2461 fails:
  2462 
  2463   assume "A & B" then have A and B ..   (*".." fails*)
  2464 
  2465 better use "obtain" in situations as above; alternative refer to
  2466 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  2467 
  2468 * Pure: proper integration with ``locales''; unlike the original
  2469 version by Florian Kammller, Isar locales package high-level proof
  2470 contexts rather than raw logical ones (e.g. we admit to include
  2471 attributes everywhere); operations on locales include merge and
  2472 rename; support for implicit arguments (``structures''); simultaneous
  2473 type-inference over imports and text; see also HOL/ex/Locales.thy for
  2474 some examples;
  2475 
  2476 * Pure: the following commands have been ``localized'', supporting a
  2477 target locale specification "(in name)": 'lemma', 'theorem',
  2478 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  2479 stored both within the locale and at the theory level (exported and
  2480 qualified by the locale name);
  2481 
  2482 * Pure: theory goals may now be specified in ``long'' form, with
  2483 ad-hoc contexts consisting of arbitrary locale elements. for example
  2484 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  2485 definitions may be given, too); the result is a meta-level rule with
  2486 the context elements being discharged in the obvious way;
  2487 
  2488 * Pure: new proof command 'using' allows to augment currently used
  2489 facts after a goal statement ('using' is syntactically analogous to
  2490 'apply', but acts on the goal's facts only); this allows chained facts
  2491 to be separated into parts given before and after a claim, as in
  2492 ``from a and b have C using d and e <proof>'';
  2493 
  2494 * Pure: renamed "antecedent" case to "rule_context";
  2495 
  2496 * Pure: new 'judgment' command records explicit information about the
  2497 object-logic embedding (used by several tools internally); no longer
  2498 use hard-wired "Trueprop";
  2499 
  2500 * Pure: added 'corollary' command;
  2501 
  2502 * Pure: fixed 'token_translation' command;
  2503 
  2504 * Pure: removed obsolete 'exported' attribute;
  2505 
  2506 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  2507 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  2508 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  2509 
  2510 * Pure: method 'atomize' presents local goal premises as object-level
  2511 statements (atomic meta-level propositions); setup controlled via
  2512 rewrite rules declarations of 'atomize' attribute; example
  2513 application: 'induct' method with proper rule statements in improper
  2514 proof *scripts*;
  2515 
  2516 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  2517 now consider the syntactic context of assumptions, giving a better
  2518 chance to get type-inference of the arguments right (this is
  2519 especially important for locales);
  2520 
  2521 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  2522 mode;
  2523 
  2524 * Pure/obtain: the formal conclusion "thesis", being marked as
  2525 ``internal'', may no longer be reference directly in the text;
  2526 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  2527 situations;
  2528 
  2529 * Pure: generic 'sym' attribute which declares a rule both as pure
  2530 'elim?' and for the 'symmetric' operation;
  2531 
  2532 * Pure: marginal comments ``--'' may now occur just anywhere in the
  2533 text; the fixed correlation with particular command syntax has been
  2534 discontinued;
  2535 
  2536 * Pure: new method 'rules' is particularly well-suited for proof
  2537 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  2538 but often produces more compact proof terms with less detours;
  2539 
  2540 * Pure/Provers/classical: simplified integration with pure rule
  2541 attributes and methods; the classical "intro?/elim?/dest?"
  2542 declarations coincide with the pure ones; the "rule" method no longer
  2543 includes classically swapped intros; "intro" and "elim" methods no
  2544 longer pick rules from the context; also got rid of ML declarations
  2545 AddXIs/AddXEs/AddXDs; all of this has some potential for
  2546 INCOMPATIBILITY;
  2547 
  2548 * Provers/classical: attribute 'swapped' produces classical inversions
  2549 of introduction rules;
  2550 
  2551 * Provers/simplifier: 'simplified' attribute may refer to explicit
  2552 rules instead of full simplifier context; 'iff' attribute handles
  2553 conditional rules;
  2554 
  2555 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  2556 
  2557 * HOL: 'recdef' now fails on unfinished automated proofs, use
  2558 "(permissive)" option to recover old behavior;
  2559 
  2560 * HOL: 'inductive' no longer features separate (collective) attributes
  2561 for 'intros' (was found too confusing);
  2562 
  2563 * HOL: properly declared induction rules less_induct and
  2564 wf_induct_rule;
  2565 
  2566 
  2567 *** HOL ***
  2568 
  2569 * HOL: moved over to sane numeral syntax; the new policy is as
  2570 follows:
  2571 
  2572   - 0 and 1 are polymorphic constants, which are defined on any
  2573   numeric type (nat, int, real etc.);
  2574 
  2575   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  2576   binary representation internally;
  2577 
  2578   - type nat has special constructor Suc, and generally prefers Suc 0
  2579   over 1::nat and Suc (Suc 0) over 2::nat;
  2580 
  2581 This change may cause significant problems of INCOMPATIBILITY; here
  2582 are some hints on converting existing sources:
  2583 
  2584   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  2585   entities, so expressions involving "-" (unary or binary minus) need
  2586   to be spaced properly;
  2587 
  2588   - existing occurrences of "1" may need to be constraint "1::nat" or
  2589   even replaced by Suc 0; similar for old "2";
  2590 
  2591   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  2592 
  2593   - remove all special provisions on numerals in proofs;
  2594 
  2595 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  2596 representation (depends on bin_arith_simps in the default context);
  2597 
  2598 * HOL: symbolic syntax for x^2 (numeral 2);
  2599 
  2600 * HOL: the class of all HOL types is now called "type" rather than
  2601 "term"; INCOMPATIBILITY, need to adapt references to this type class
  2602 in axclass/classes, instance/arities, and (usually rare) occurrences
  2603 in typings (of consts etc.); internally the class is called
  2604 "HOL.type", ML programs should refer to HOLogic.typeS;
  2605 
  2606 * HOL/record package improvements:
  2607   - new derived operations "fields" to build a partial record section,
  2608     "extend" to promote a fixed record to a record scheme, and
  2609     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  2610     declared as simp by default;
  2611   - shared operations ("more", "fields", etc.) now need to be always
  2612     qualified) --- potential INCOMPATIBILITY;
  2613   - removed "make_scheme" operations (use "make" with "extend") --
  2614     INCOMPATIBILITY;
  2615   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  2616   - provides cases/induct rules for use with corresponding Isar
  2617     methods (for concrete records, record schemes, concrete more
  2618     parts, and schematic more parts -- in that order);
  2619   - internal definitions directly based on a light-weight abstract
  2620     theory of product types over typedef rather than datatype;
  2621 
  2622 * HOL: generic code generator for generating executable ML code from
  2623 specifications; specific support for HOL constructs such as inductive
  2624 datatypes and sets, as well as recursive functions; can be invoked
  2625 via 'generate_code' theory section;
  2626 
  2627 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  2628 
  2629 * HOL: consolidated and renamed several theories.  In particular:
  2630         Ord.thy has been absorbed into HOL.thy
  2631         String.thy has been absorbed into List.thy
  2632 
  2633 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  2634 (beware of argument permutation!);
  2635 
  2636 * HOL: linorder_less_split superseded by linorder_cases;
  2637 
  2638 * HOL/List: "nodups" renamed to "distinct";
  2639 
  2640 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  2641 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  2642   - Ex_def has changed, now need to use some_eq_ex
  2643 
  2644 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  2645 in this (rare) case use:
  2646 
  2647   delSWrapper "split_all_tac"
  2648   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  2649 
  2650 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  2651 MAY FAIL;
  2652 
  2653 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  2654 Isabelle's type classes, ^ on functions and relations has too general
  2655 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  2656 necessary to attach explicit type constraints;
  2657 
  2658 * HOL/Relation: the prefix name of the infix "O" has been changed from
  2659 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  2660 renamed accordingly (eg "compI" -> "rel_compI").
  2661 
  2662 * HOL: syntax translations now work properly with numerals and records
  2663 expressions;
  2664 
  2665 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  2666 of "lam" -- INCOMPATIBILITY;
  2667 
  2668 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  2669 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  2670 renamed "Product_Type.unit";
  2671 
  2672 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  2673 
  2674 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  2675 the "cases" method);
  2676 
  2677 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  2678 Florian Kammller);
  2679 
  2680 * HOL/IMP: updated and converted to new-style theory format; several
  2681 parts turned into readable document, with proper Isar proof texts and
  2682 some explanations (by Gerwin Klein);
  2683 
  2684 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  2685 
  2686 * HOL-Hyperreal is now a logic image;
  2687 
  2688 
  2689 *** HOLCF ***
  2690 
  2691 * Isar: consts/constdefs supports mixfix syntax for continuous
  2692 operations;
  2693 
  2694 * Isar: domain package adapted to new-style theory format, e.g. see
  2695 HOLCF/ex/Dnat.thy;
  2696 
  2697 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  2698 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  2699 lift.induct_tac, always use UU instead of Undef;
  2700 
  2701 * HOLCF/IMP: updated and converted to new-style theory;
  2702 
  2703 
  2704 *** ZF ***
  2705 
  2706 * Isar: proper integration of logic-specific tools and packages,
  2707 including theory commands '(co)inductive', '(co)datatype',
  2708 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  2709 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  2710 
  2711 * theory Main no longer includes AC; for the Axiom of Choice, base
  2712 your theory on Main_ZFC;
  2713 
  2714 * the integer library now covers quotients and remainders, with many
  2715 laws relating division to addition, multiplication, etc.;
  2716 
  2717 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  2718 typeless version of the formalism;
  2719 
  2720 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  2721 format;
  2722 
  2723 * ZF/Induct: new directory for examples of inductive definitions,
  2724 including theory Multiset for multiset orderings; converted to
  2725 new-style theory format;
  2726 
  2727 * ZF: many new theorems about lists, ordinals, etc.;
  2728 
  2729 
  2730 *** General ***
  2731 
  2732 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  2733 variable proof controls level of detail: 0 = no proofs (only oracle
  2734 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  2735 also ref manual for further ML interfaces;
  2736 
  2737 * Pure/axclass: removed obsolete ML interface
  2738 goal_subclass/goal_arity;
  2739 
  2740 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  2741 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  2742 separate tokens, so expressions involving minus need to be spaced
  2743 properly;
  2744 
  2745 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  2746 rather than "infixl" or "infixr";
  2747 
  2748 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  2749 sort constraint specifications in type inference; e.g. "x::_::foo"
  2750 ensures that the type of "x" is of sort "foo" (but not necessarily a
  2751 type variable);
  2752 
  2753 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  2754 control output of nested => (types); the default behavior is
  2755 "type_brackets";
  2756 
  2757 * Pure/syntax: builtin parse translation for "_constify" turns valued
  2758 tokens into AST constants;
  2759 
  2760 * Pure/syntax: prefer later declarations of translations and print
  2761 translation functions; potential INCOMPATIBILITY: need to reverse
  2762 multiple declarations for same syntax element constant;
  2763 
  2764 * Pure/show_hyps reset by default (in accordance to existing Isar
  2765 practice);
  2766 
  2767 * Provers/classical: renamed addaltern to addafter, addSaltern to
  2768 addSafter;
  2769 
  2770 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  2771 as well;
  2772 
  2773 * system: tested support for MacOS X; should be able to get Isabelle +
  2774 Proof General to work in a plain Terminal after installing Poly/ML
  2775 (e.g. from the Isabelle distribution area) and GNU bash alone
  2776 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  2777 support requires further installations, e.g. from
  2778 http://fink.sourceforge.net/);
  2779 
  2780 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  2781 
  2782 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  2783 of 40 MB), cf. ML_OPTIONS;
  2784 
  2785 * system: Proof General keywords specification is now part of the
  2786 Isabelle distribution (see etc/isar-keywords.el);
  2787 
  2788 * system: support for persistent Proof General sessions (refrain from
  2789 outdating all loaded theories on startup); user may create writable
  2790 logic images like this: ``isabelle -q HOL Test'';
  2791 
  2792 * system: smart selection of Isabelle process versus Isabelle
  2793 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  2794 run both "isabelle" and "Isabelle" even if file names are badly
  2795 damaged (executable inspects the case of the first letter of its own
  2796 name); added separate "isabelle-process" and "isabelle-interface";
  2797 
  2798 * system: refrain from any attempt at filtering input streams; no
  2799 longer support ``8bit'' encoding of old isabelle font, instead proper
  2800 iso-latin characters may now be used; the related isatools
  2801 "symbolinput" and "nonascii" have disappeared as well;
  2802 
  2803 * system: removed old "xterm" interface (the print modes "xterm" and
  2804 "xterm_color" are still available for direct use in a suitable
  2805 terminal);
  2806 
  2807 
  2808 
  2809 New in Isabelle99-2 (February 2001)
  2810 -----------------------------------
  2811 
  2812 *** Overview of INCOMPATIBILITIES ***
  2813 
  2814 * HOL: please note that theories in the Library and elsewhere often use the
  2815 new-style (Isar) format; to refer to their theorems in an ML script you must
  2816 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  2817 
  2818 * HOL: inductive package no longer splits induction rule aggressively,
  2819 but only as far as specified by the introductions given; the old
  2820 format may be recovered via ML function complete_split_rule or attribute
  2821 'split_rule (complete)';
  2822 
  2823 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  2824 gfp_Tarski to gfp_unfold;
  2825 
  2826 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  2827 
  2828 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  2829 relation); infix "^^" has been renamed "``"; infix "``" has been
  2830 renamed "`"; "univalent" has been renamed "single_valued";
  2831 
  2832 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  2833 operation;
  2834 
  2835 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  2836 
  2837 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  2838 
  2839 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  2840 consequence, it is no longer monotonic wrt. the local goal context
  2841 (which is now passed through the inductive cases);
  2842 
  2843 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  2844 \<gg> to \<ggreater>;
  2845 
  2846 
  2847 *** Document preparation ***
  2848 
  2849 * \isabellestyle{NAME} selects version of Isabelle output (currently
  2850 available: are "it" for near math-mode best-style output, "sl" for
  2851 slanted text style, and "tt" for plain type-writer; if no
  2852 \isabellestyle command is given, output is according to slanted
  2853 type-writer);
  2854 
  2855 * support sub/super scripts (for single symbols only), input syntax is
  2856 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  2857 
  2858 * some more standard symbols; see Appendix A of the system manual for
  2859 the complete list of symbols defined in isabellesym.sty;
  2860 
  2861 * improved isabelle style files; more abstract symbol implementation
  2862 (should now use \isamath{...} and \isatext{...} in custom symbol
  2863 definitions);
  2864 
  2865 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  2866 state; Note that presentation of goal states does not conform to
  2867 actual human-readable proof documents.  Please do not include goal
  2868 states into document output unless you really know what you are doing!
  2869 
  2870 * proper indentation of antiquoted output with proportional LaTeX
  2871 fonts;
  2872 
  2873 * no_document ML operator temporarily disables LaTeX document
  2874 generation;
  2875 
  2876 * isatool unsymbolize tunes sources for plain ASCII communication;
  2877 
  2878 
  2879 *** Isar ***
  2880 
  2881 * Pure: Isar now suffers initial goal statements to contain unbound
  2882 schematic variables (this does not conform to actual readable proof
  2883 documents, due to unpredictable outcome and non-compositional proof
  2884 checking); users who know what they are doing may use schematic goals
  2885 for Prolog-style synthesis of proven results;
  2886 
  2887 * Pure: assumption method (an implicit finishing) now handles actual
  2888 rules as well;
  2889 
  2890 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  2891 initial goal, declare "that" only as Pure intro (only for single
  2892 steps); the "that" rule assumption may now be involved in implicit
  2893 finishing, thus ".." becomes a feasible for trivial obtains;
  2894 
  2895 * Pure: default proof step now includes 'intro_classes'; thus trivial
  2896 instance proofs may be performed by "..";
  2897 
  2898 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  2899 statements as well;
  2900 
  2901 * Pure: more robust selection of calculational rules;
  2902 
  2903 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  2904 rule (as well as the assumption rule);
  2905 
  2906 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  2907 lemmas, using the graph browser tool;
  2908 
  2909 * Pure: predict failure of "show" in interactive mode;
  2910 
  2911 * Pure: 'thms_containing' now takes actual terms as arguments;
  2912 
  2913 * HOL: improved method 'induct' --- now handles non-atomic goals
  2914 (potential INCOMPATIBILITY); tuned error handling;
  2915 
  2916 * HOL: cases and induct rules now provide explicit hints about the
  2917 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  2918 any remaining facts are inserted into the goal verbatim;
  2919 
  2920 * HOL: local contexts (aka cases) may now contain term bindings as
  2921 well; the 'cases' and 'induct' methods new provide a ?case binding for
  2922 the result to be shown in each case;
  2923 
  2924 * HOL: added 'recdef_tc' command;
  2925 
  2926 * isatool convert assists in eliminating legacy ML scripts;
  2927 
  2928 
  2929 *** HOL ***
  2930 
  2931 * HOL/Library: a collection of generic theories to be used together
  2932 with main HOL; the theory loader path already includes this directory
  2933 by default; the following existing theories have been moved here:
  2934 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  2935 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  2936 
  2937 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  2938 modelling and verification task performed in Isabelle/HOL +
  2939 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  2940 
  2941 * HOL/Algebra: special summation operator SUM no longer exists, it has
  2942 been replaced by setsum; infix 'assoc' now has priority 50 (like
  2943 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  2944 'domain', this makes the theory consistent with mathematical
  2945 literature;
  2946 
  2947 * HOL basics: added overloaded operations "inverse" and "divide"
  2948 (infix "/"), syntax for generic "abs" operation, generic summation
  2949 operator \<Sum>;
  2950 
  2951 * HOL/typedef: simplified package, provide more useful rules (see also
  2952 HOL/subset.thy);
  2953 
  2954 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  2955 now expressed as a proper nested rule (old-style tactic scripts may
  2956 require atomize_strip_tac to cope with non-atomic premises);
  2957 
  2958 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  2959 to "split_conv" (old name still available for compatibility);
  2960 
  2961 * HOL: improved concrete syntax for strings (e.g. allows translation
  2962 rules with string literals);
  2963 
  2964 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  2965  and Fleuriot's mechanization of analysis, including the transcendental
  2966  functions for the reals;
  2967 
  2968 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  2969 
  2970 
  2971 *** CTT ***
  2972 
  2973 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  2974 "lam" is displayed as TWO lambda-symbols
  2975 
  2976 * CTT: theory Main now available, containing everything (that is, Bool
  2977 and Arith);
  2978 
  2979 
  2980 *** General ***
  2981 
  2982 * Pure: the Simplifier has been implemented properly as a derived rule
  2983 outside of the actual kernel (at last!); the overall performance
  2984 penalty in practical applications is about 50%, while reliability of
  2985 the Isabelle inference kernel has been greatly improved;
  2986 
  2987 * print modes "brackets" and "no_brackets" control output of nested =>
  2988 (types) and ==> (props); the default behaviour is "brackets";
  2989 
  2990 * Provers: fast_tac (and friends) now handle actual object-logic rules
  2991 as assumptions as well;
  2992 
  2993 * system: support Poly/ML 4.0;
  2994 
  2995 * system: isatool install handles KDE version 1 or 2;
  2996 
  2997 
  2998 
  2999 New in Isabelle99-1 (October 2000)
  3000 ----------------------------------
  3001 
  3002 *** Overview of INCOMPATIBILITIES ***
  3003 
  3004 * HOL: simplification of natural numbers is much changed; to partly
  3005 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  3006 issue the following ML commands:
  3007 
  3008   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  3009   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  3010 
  3011 * HOL: simplification no longer dives into case-expressions; this is
  3012 controlled by "t.weak_case_cong" for each datatype t;
  3013 
  3014 * HOL: nat_less_induct renamed to less_induct;
  3015 
  3016 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  3017 fixsome to patch .thy and .ML sources automatically;
  3018 
  3019   select_equality  -> some_equality
  3020   select_eq_Ex     -> some_eq_ex
  3021   selectI2EX       -> someI2_ex
  3022   selectI2         -> someI2
  3023   selectI          -> someI
  3024   select1_equality -> some1_equality
  3025   Eps_sym_eq       -> some_sym_eq_trivial
  3026   Eps_eq           -> some_eq_trivial
  3027 
  3028 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  3029 
  3030 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  3031 instead);
  3032 
  3033 * HOL: the recursion equations generated by 'recdef' are now called
  3034 f.simps instead of f.rules;
  3035 
  3036 * HOL: qed_spec_mp now also handles bounded ALL as well;
  3037 
  3038 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  3039 sometimes be needed;
  3040 
  3041 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  3042 
  3043 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  3044 
  3045 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  3046 product is now "<*>" instead of "Times"; the lexicographic product is
  3047 now "<*lex*>" instead of "**";
  3048 
  3049 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  3050 of main HOL, but was unused); better use HOL's datatype package;
  3051 
  3052 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  3053 the old syntax may be recovered as follows:
  3054 
  3055   syntax (symbols)
  3056     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  3057       (infixl "\\<oplus>" 100)
  3058 
  3059 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3060 
  3061 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  3062 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  3063 internally;
  3064 
  3065 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  3066 changed from A/r to A//r;
  3067 
  3068 * ZF: new treatment of arithmetic (nat & int) may break some old
  3069 proofs;
  3070 
  3071 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  3072 rulify -> rule_format, elimify -> elim_format, ...);
  3073 
  3074 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3075 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  3076 should have to change intro!! to intro? only); replaced "delrule" by
  3077 "rule del";
  3078 
  3079 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  3080 
  3081 * Provers: strengthened force_tac by using new first_best_tac;
  3082 
  3083 * LaTeX document preparation: several changes of isabelle.sty (see
  3084 lib/texinputs);
  3085 
  3086 
  3087 *** Document preparation ***
  3088 
  3089 * formal comments (text blocks etc.) in new-style theories may now
  3090 contain antiquotations of thm/prop/term/typ/text to be presented
  3091 according to latex print mode; concrete syntax is like this:
  3092 @{term[show_types] "f(x) = a + x"};
  3093 
  3094 * isatool mkdir provides easy setup of Isabelle session directories,
  3095 including proper document sources;
  3096 
  3097 * generated LaTeX sources are now deleted after successful run
  3098 (isatool document -c); may retain a copy somewhere else via -D option
  3099 of isatool usedir;
  3100 
  3101 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  3102 style files, achieving self-contained LaTeX sources and simplifying
  3103 LaTeX debugging;
  3104 
  3105 * old-style theories now produce (crude) LaTeX output as well;
  3106 
  3107 * browser info session directories are now self-contained (may be put
  3108 on WWW server seperately); improved graphs of nested sessions; removed
  3109 graph for 'all sessions';
  3110 
  3111 * several improvements in isabelle style files; \isabellestyle{it}
  3112 produces fake math mode output; \isamarkupheader is now \section by
  3113 default; see lib/texinputs/isabelle.sty etc.;
  3114 
  3115 
  3116 *** Isar ***
  3117 
  3118 * Isar/Pure: local results and corresponding term bindings are now
  3119 subject to Hindley-Milner polymorphism (similar to ML); this
  3120 accommodates incremental type-inference very nicely;
  3121 
  3122 * Isar/Pure: new derived language element 'obtain' supports
  3123 generalized existence reasoning;
  3124 
  3125 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  3126 support accumulation of results, without applying any rules yet;
  3127 useful to collect intermediate results without explicit name
  3128 references, and for use with transitivity rules with more than 2
  3129 premises;
  3130 
  3131 * Isar/Pure: scalable support for case-analysis type proofs: new
  3132 'case' language element refers to local contexts symbolically, as
  3133 produced by certain proof methods; internally, case names are attached
  3134 to theorems as "tags";
  3135 
  3136 * Isar/Pure: theory command 'hide' removes declarations from
  3137 class/type/const name spaces;
  3138 
  3139 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  3140 indicate potential overloading;
  3141 
  3142 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  3143 
  3144 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  3145 "{a,b,c}" instead of {a,b,c};
  3146 
  3147 * Isar/Pure now provides its own version of intro/elim/dest
  3148 attributes; useful for building new logics, but beware of confusion
  3149 with the version in Provers/classical;
  3150 
  3151 * Isar/Pure: the local context of (non-atomic) goals is provided via
  3152 case name 'antecedent';
  3153 
  3154 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  3155 to the current context is now done automatically);
  3156 
  3157 * Isar/Pure: theory command 'method_setup' provides a simple interface
  3158 for definining proof methods in ML;
  3159 
  3160 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3161 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  3162 most cases, one should have to change intro!! to intro? only);
  3163 replaced "delrule" by "rule del";
  3164 
  3165 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  3166 'symmetric' attribute (the latter supercedes [RS sym]);
  3167 
  3168 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  3169 method modifier); 'simp' method: 'only:' modifier removes loopers as
  3170 well (including splits);
  3171 
  3172 * Isar/Provers: Simplifier and Classical methods now support all kind
  3173 of modifiers used in the past, including 'cong', 'iff', etc.
  3174 
  3175 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  3176 of Simplifier and Classical reasoner);
  3177 
  3178 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  3179 now support named cases; major packages (inductive, datatype, primrec,
  3180 recdef) support case names and properly name parameters;
  3181 
  3182 * Isar/HOL: new transitivity rules for substitution in inequalities --
  3183 monotonicity conditions are extracted to be proven at end of
  3184 calculations;
  3185 
  3186 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  3187 method anyway;
  3188 
  3189 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  3190 split_if split_if_asm; datatype package provides theorems foo.splits =
  3191 foo.split foo.split_asm for each datatype;
  3192 
  3193 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  3194 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  3195 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  3196 use "(cases (simplified))" method in proper proof texts);
  3197 
  3198 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  3199 
  3200 * Isar: names of theorems etc. may be natural numbers as well;
  3201 
  3202 * Isar: 'pr' command: optional arguments for goals_limit and
  3203 ProofContext.prems_limit; no longer prints theory contexts, but only
  3204 proof states;
  3205 
  3206 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  3207 additional print modes to be specified; e.g. "pr(latex)" will print
  3208 proof state according to the Isabelle LaTeX style;
  3209 
  3210 * Isar: improved support for emulating tactic scripts, including proof
  3211 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  3212 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  3213 (for HOL datatypes);
  3214 
  3215 * Isar: simplified (more robust) goal selection of proof methods: 1st
  3216 goal, all goals, or explicit goal specifier (tactic emulation); thus
  3217 'proof method scripts' have to be in depth-first order;
  3218 
  3219 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  3220 
  3221 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  3222 should instead use individual commands for printing items
  3223 (print_commands, print_methods etc.);
  3224 
  3225 * Isar: added 'nothing' --- the empty list of theorems;
  3226 
  3227 
  3228 *** HOL ***
  3229 
  3230 * HOL/MicroJava: formalization of a fragment of Java, together with a
  3231 corresponding virtual machine and a specification of its bytecode
  3232 verifier and a lightweight bytecode verifier, including proofs of
  3233 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  3234 Cornelia Pusch (see also the homepage of project Bali at
  3235 http://isabelle.in.tum.de/Bali/);
  3236 
  3237 * HOL/Algebra: new theory of rings and univariate polynomials, by
  3238 Clemens Ballarin;
  3239 
  3240 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  3241 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  3242 Rasmussen;
  3243 
  3244 * HOL/Lattice: fundamental concepts of lattice theory and order
  3245 structures, including duals, properties of bounds versus algebraic
  3246 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  3247 Theorem for complete lattices etc.; may also serve as a demonstration
  3248 for abstract algebraic reasoning using axiomatic type classes, and
  3249 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  3250 
  3251 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  3252 von Oheimb;
  3253 
  3254 * HOL/IMPP: extension of IMP with local variables and mutually
  3255 recursive procedures, by David von Oheimb;
  3256 
  3257 * HOL/Lambda: converted into new-style theory and document;
  3258 
  3259 * HOL/ex/Multiquote: example of multiple nested quotations and
  3260 anti-quotations -- basically a generalized version of de-Bruijn
  3261 representation; very useful in avoiding lifting of operations;
  3262 
  3263 * HOL/record: added general record equality rule to simpset; fixed
  3264 select-update simplification procedure to handle extended records as
  3265 well; admit "r" as field name;
  3266 
  3267 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  3268 other numeric types and also as the identity of groups, rings, etc.;
  3269 
  3270 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  3271 Types nat and int belong to this axclass;
  3272 
  3273 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  3274    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  3275    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  3276   two terms #m*u and #n*u are replaced by #(m+n)*u
  3277     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  3278   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  3279     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  3280 
  3281 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  3282 powerful prover for predicate logic but knows nothing of clasets; see
  3283 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  3284 
  3285 * HOL: new version of "case_tac" subsumes both boolean case split and
  3286 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  3287 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  3288 
  3289 * HOL: simplification no longer dives into case-expressions: only the
  3290 selector expression is simplified, but not the remaining arms; to
  3291 enable full simplification of case-expressions for datatype t, you may
  3292 remove t.weak_case_cong from the simpset, either globally (Delcongs
  3293 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  3294 
  3295 * HOL/recdef: the recursion equations generated by 'recdef' for
  3296 function 'f' are now called f.simps instead of f.rules; if all
  3297 termination conditions are proved automatically, these simplification
  3298 rules are added to the simpset, as in primrec; rules may be named
  3299 individually as well, resulting in a separate list of theorems for
  3300 each equation;
  3301 
  3302 * HOL/While is a new theory that provides a while-combinator. It
  3303 permits the definition of tail-recursive functions without the
  3304 provision of a termination measure. The latter is necessary once the
  3305 invariant proof rule for while is applied.
  3306 
  3307 * HOL: new (overloaded) notation for the set of elements below/above
  3308 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  3309 
  3310 * HOL: theorems impI, allI, ballI bound as "strip";
  3311 
  3312 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  3313 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  3314 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  3315 
  3316 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3317 
  3318 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  3319 main HOL, but was unused);
  3320 
  3321 * HOL: fewer consts declared as global (e.g. have to refer to
  3322 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  3323 
  3324 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  3325 in case of overlap with user translations (e.g. judgements over
  3326 tuples); (note that the underlying logical represenation is still
  3327 bogus);
  3328 
  3329 
  3330 *** ZF ***
  3331 
  3332 * ZF: simplification automatically cancels common terms in arithmetic
  3333 expressions over nat and int;
  3334 
  3335 * ZF: new treatment of nat to minimize type-checking: all operators
  3336 coerce their operands to a natural number using the function natify,
  3337 making the algebraic laws unconditional;
  3338 
  3339 * ZF: as above, for int: operators coerce their operands to an integer
  3340 using the function intify;
  3341 
  3342 * ZF: the integer library now contains many of the usual laws for the
  3343 orderings, including $<=, and monotonicity laws for $+ and $*;
  3344 
  3345 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  3346 simplification;
  3347 
  3348 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  3349 to the simplifier and classical reasoner simultaneously;
  3350 
  3351 
  3352 *** General ***
  3353 
  3354 * Provers: blast_tac now handles actual object-logic rules as
  3355 assumptions; note that auto_tac uses blast_tac internally as well;
  3356 
  3357 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  3358 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  3359 
  3360 * Provers: delrules now handles destruct rules as well (no longer need
  3361 explicit make_elim);
  3362 
  3363 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  3364   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3365 use instead the strong form,
  3366   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3367 in HOL, FOL and ZF the function cla_make_elim will create such rules
  3368 from destruct-rules;
  3369 
  3370 * Provers: Simplifier.easy_setup provides a fast path to basic
  3371 Simplifier setup for new object-logics;
  3372 
  3373 * Pure: AST translation rules no longer require constant head on LHS;
  3374 
  3375 * Pure: improved name spaces: ambiguous output is qualified; support
  3376 for hiding of names;
  3377 
  3378 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  3379 XSYMBOL_HOME; no longer need to do manual configuration in most
  3380 situations;
  3381 
  3382 * system: compression of ML heaps images may now be controlled via -c
  3383 option of isabelle and isatool usedir (currently only observed by
  3384 Poly/ML);
  3385 
  3386 * system: isatool installfonts may handle X-Symbol fonts as well (very
  3387 useful for remote X11);
  3388 
  3389 * system: provide TAGS file for Isabelle sources;
  3390 
  3391 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  3392 order;
  3393 
  3394 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  3395 timing flag supersedes proof_timing and Toplevel.trace;
  3396 
  3397 * ML: new combinators |>> and |>>> for incremental transformations
  3398 with secondary results (e.g. certain theory extensions):
  3399 
  3400 * ML: PureThy.add_defs gets additional argument to indicate potential
  3401 overloading (usually false);
  3402 
  3403 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  3404 results;
  3405 
  3406 
  3407 
  3408 New in Isabelle99 (October 1999)
  3409 --------------------------------
  3410 
  3411 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3412 
  3413 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  3414 are no longer simplified.  (This allows the simplifier to unfold recursive
  3415 functional programs.)  To restore the old behaviour, declare
  3416 
  3417     Delcongs [if_weak_cong];
  3418 
  3419 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  3420 complement;
  3421 
  3422 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  3423 
  3424 * HOL/datatype: mutual_induct_tac no longer exists --
  3425   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  3426 
  3427 * HOL/typedef: fixed type inference for representing set; type
  3428 arguments now have to occur explicitly on the rhs as type constraints;
  3429 
  3430 * ZF: The con_defs part of an inductive definition may no longer refer
  3431 to constants declared in the same theory;
  3432 
  3433 * HOL, ZF: the function mk_cases, generated by the inductive
  3434 definition package, has lost an argument.  To simplify its result, it
  3435 uses the default simpset instead of a supplied list of theorems.
  3436 
  3437 * HOL/List: the constructors of type list are now Nil and Cons;
  3438 
  3439 * Simplifier: the type of the infix ML functions
  3440         setSSolver addSSolver setSolver addSolver
  3441 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  3442 for packaging solvers. A solver is created via
  3443         mk_solver: string -> (thm list -> int -> tactic) -> solver
  3444 where the string argument is only a comment.
  3445 
  3446 
  3447 *** Proof tools ***
  3448 
  3449 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  3450 decision procedure for linear arithmetic. Currently it is used for
  3451 types `nat', `int', and `real' in HOL (see below); it can, should and
  3452 will be instantiated for other types and logics as well.
  3453 
  3454 * The simplifier now accepts rewrite rules with flexible heads, eg
  3455      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  3456   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  3457   matching.
  3458 
  3459 
  3460 *** General ***
  3461 
  3462 * New Isabelle/Isar subsystem provides an alternative to traditional
  3463 tactical theorem proving; together with the ProofGeneral/isar user
  3464 interface it offers an interactive environment for developing human
  3465 readable proof documents (Isar == Intelligible semi-automated
  3466 reasoning); for further information see isatool doc isar-ref,
  3467 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  3468 
  3469 * improved and simplified presentation of theories: better HTML markup
  3470 (including colors), graph views in several sizes; isatool usedir now
  3471 provides a proper interface for user theories (via -P option); actual
  3472 document preparation based on (PDF)LaTeX is available as well (for
  3473 new-style theories only); see isatool doc system for more information;
  3474 
  3475 * native support for Proof General, both for classic Isabelle and
  3476 Isabelle/Isar;
  3477 
  3478 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  3479 using the graph browser tool;
  3480 
  3481 * Isabelle manuals now also available as PDF;
  3482 
  3483 * theory loader rewritten from scratch (may not be fully
  3484 bug-compatible); old loadpath variable has been replaced by show_path,
  3485 add_path, del_path, reset_path functions; new operations such as
  3486 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  3487 isatool doc ref);
  3488 
  3489 * improved isatool install: option -k creates KDE application icon,
  3490 option -p DIR installs standalone binaries;
  3491 
  3492 * added ML_PLATFORM setting (useful for cross-platform installations);
  3493 more robust handling of platform specific ML images for SML/NJ;
  3494 
  3495 * the settings environment is now statically scoped, i.e. it is never
  3496 created again in sub-processes invoked from isabelle, isatool, or
  3497 Isabelle;
  3498 
  3499 * path element specification '~~' refers to '$ISABELLE_HOME';
  3500 
  3501 * in locales, the "assumes" and "defines" parts may be omitted if
  3502 empty;
  3503 
  3504 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  3505 long arrows);
  3506 
  3507 * new print_mode "HTML";
  3508 
  3509 * new flag show_tags controls display of tags of theorems (which are
  3510 basically just comments that may be attached by some tools);
  3511 
  3512 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  3513 mode and goal output format:
  3514 
  3515 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  3516 244c244
  3517 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  3518 ---
  3519 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  3520 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  3521 181c181
  3522 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  3523 ---
  3524 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  3525 
  3526 * function bind_thms stores lists of theorems (cf. bind_thm);
  3527 
  3528 * new shorthand tactics ftac, eatac, datac, fatac;
  3529 
  3530 * qed (and friends) now accept "" as result name; in that case the
  3531 theorem is not stored, but proper checks and presentation of the
  3532 result still apply;
  3533 
  3534 * theorem database now also indexes constants "Trueprop", "all",
  3535 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  3536 
  3537 
  3538 *** HOL ***
  3539 
  3540 ** HOL arithmetic **
  3541 
  3542 * There are now decision procedures for linear arithmetic over nat and
  3543 int:
  3544 
  3545 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  3546 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  3547 are treated as atomic; subformulae not involving type `nat' or `int'
  3548 are ignored; quantified subformulae are ignored unless they are
  3549 positive universal or negative existential. The tactic has to be
  3550 invoked by hand and can be a little bit slow. In particular, the
  3551 running time is exponential in the number of occurrences of `min' and
  3552 `max', and `-' on `nat'.
  3553 
  3554 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  3555 (negated) (in)equalities among the premises and the conclusion into
  3556 account (i.e. no compound formulae) and does not know about `min' and
  3557 `max', and `-' on `nat'. It is fast and is used automatically by the
  3558 simplifier.
  3559 
  3560 NB: At the moment, these decision procedures do not cope with mixed
  3561 nat/int formulae where the two parts interact, such as `m < n ==>
  3562 int(m) < int(n)'.
  3563 
  3564 * HOL/Numeral provides a generic theory of numerals (encoded
  3565 efficiently as bit strings); setup for types nat/int/real is in place;
  3566 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  3567 int, existing theories and proof scripts may require a few additional
  3568 type constraints;
  3569 
  3570 * integer division and remainder can now be performed on constant
  3571 arguments;
  3572 
  3573 * many properties of integer multiplication, division and remainder
  3574 are now available;
  3575 
  3576 * An interface to the Stanford Validity Checker (SVC) is available through the
  3577 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  3578 are proved automatically.  SVC must be installed separately, and its results
  3579 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  3580 invocation of the underlying oracle).  For SVC see
  3581   http://verify.stanford.edu/SVC
  3582 
  3583 * IsaMakefile: the HOL-Real target now builds an actual image;
  3584 
  3585 
  3586 ** HOL misc **
  3587 
  3588 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  3589 (in Isabelle/Isar) -- by Gertrud Bauer;
  3590 
  3591 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  3592 analysis for assembly languages with subtypes;
  3593 
  3594 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  3595 -- avoids syntactic ambiguities and treats state, transition, and
  3596 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  3597 changed syntax and (many) tactics;
  3598 
  3599 * HOL/inductive: Now also handles more general introduction rules such
  3600   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  3601   theorems are now maintained within the theory (maintained via the
  3602   "mono" attribute);
  3603 
  3604 * HOL/datatype: Now also handles arbitrarily branching datatypes
  3605   (using function types) such as
  3606 
  3607   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  3608 
  3609 * HOL/record: record_simproc (part of the default simpset) takes care
  3610 of selectors applied to updated records; record_split_tac is no longer
  3611 part of the default claset; update_defs may now be removed from the
  3612 simpset in many cases; COMPATIBILITY: old behavior achieved by
  3613 
  3614   claset_ref () := claset() addSWrapper record_split_wrapper;
  3615   Delsimprocs [record_simproc]
  3616 
  3617 * HOL/typedef: fixed type inference for representing set; type
  3618 arguments now have to occur explicitly on the rhs as type constraints;
  3619 
  3620 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  3621 names rather than an ML expression;
  3622 
  3623 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  3624 supplied later.  Program schemes can be defined, such as
  3625     "While B C s = (if B s then While B C (C s) else s)"
  3626 where the well-founded relation can be chosen after B and C have been given.
  3627 
  3628 * HOL/List: the constructors of type list are now Nil and Cons;
  3629 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  3630 course, ML tools referring to List.list.op # etc. have to be adapted;
  3631 
  3632 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  3633 disabled by default; run isabelle with option -m HOL to get back to
  3634 the original Gordon/HOL-style output;
  3635 
  3636 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  3637 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  3638 
  3639 * HOL basic syntax simplified (more orthogonal): all variants of
  3640 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  3641 Eps operator is provided as well: "SOME x. P[x]";
  3642 
  3643 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  3644 
  3645 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  3646 thus available for user theories;
  3647 
  3648 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  3649 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  3650 time;
  3651 
  3652 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  3653 several times and then mp;
  3654 
  3655 
  3656 *** LK ***
  3657 
  3658 * the notation <<...>> is now available as a notation for sequences of
  3659 formulas;
  3660 
  3661 * the simplifier is now installed
  3662 
  3663 * the axiom system has been generalized (thanks to Soren Heilmann)
  3664 
  3665 * the classical reasoner now has a default rule database
  3666 
  3667 
  3668 *** ZF ***
  3669 
  3670 * new primrec section allows primitive recursive functions to be given
  3671 directly (as in HOL) over datatypes and the natural numbers;
  3672 
  3673 * new tactics induct_tac and exhaust_tac for induction (or case
  3674 analysis) over datatypes and the natural numbers;
  3675 
  3676 * the datatype declaration of type T now defines the recursor T_rec;
  3677 
  3678 * simplification automatically does freeness reasoning for datatype
  3679 constructors;
  3680 
  3681 * automatic type-inference, with AddTCs command to insert new
  3682 type-checking rules;
  3683 
  3684 * datatype introduction rules are now added as Safe Introduction rules
  3685 to the claset;
  3686 
  3687 * the syntax "if P then x else y" is now available in addition to
  3688 if(P,x,y);
  3689 
  3690 
  3691 *** Internal programming interfaces ***
  3692 
  3693 * tuned simplifier trace output; new flag debug_simp;
  3694 
  3695 * structures Vartab / Termtab (instances of TableFun) offer efficient
  3696 tables indexed by indexname_ord / term_ord (compatible with aconv);
  3697 
  3698 * AxClass.axclass_tac lost the theory argument;
  3699 
  3700 * tuned current_goals_markers semantics: begin / end goal avoids
  3701 printing empty lines;
  3702 
  3703 * removed prs and prs_fn hook, which was broken because it did not
  3704 include \n in its semantics, forcing writeln to add one
  3705 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  3706 string -> unit if you really want to output text without newline;
  3707 
  3708 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  3709 plain output, interface builders may have to enable 'isabelle_font'
  3710 mode to get Isabelle font glyphs as before;
  3711 
  3712 * refined token_translation interface; INCOMPATIBILITY: output length
  3713 now of type real instead of int;
  3714 
  3715 * theory loader actions may be traced via new ThyInfo.add_hook
  3716 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  3717 your own database of information attached to *whole* theories -- as
  3718 opposed to intra-theory data slots offered via TheoryDataFun;
  3719 
  3720 * proper handling of dangling sort hypotheses (at last!);
  3721 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  3722 extra sort hypotheses that can be witnessed from the type signature;
  3723 the force_strip_shyps flag is gone, any remaining shyps are simply
  3724 left in the theorem (with a warning issued by strip_shyps_warning);
  3725 
  3726 
  3727 
  3728 New in Isabelle98-1 (October 1998)
  3729 ----------------------------------
  3730 
  3731 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3732 
  3733 * several changes of automated proof tools;
  3734 
  3735 * HOL: major changes to the inductive and datatype packages, including
  3736 some minor incompatibilities of theory syntax;
  3737 
  3738 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  3739 called `inj_on';
  3740 
  3741 * HOL: removed duplicate thms in Arith:
  3742   less_imp_add_less  should be replaced by  trans_less_add1
  3743   le_imp_add_le      should be replaced by  trans_le_add1
  3744 
  3745 * HOL: unary minus is now overloaded (new type constraints may be
  3746 required);
  3747 
  3748 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  3749 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  3750 now taken as an integer constant.
  3751 
  3752 * Pure: ML function 'theory_of' renamed to 'theory';
  3753 
  3754 
  3755 *** Proof tools ***
  3756 
  3757 * Simplifier:
  3758   1. Asm_full_simp_tac is now more aggressive.
  3759      1. It will sometimes reorient premises if that increases their power to
  3760         simplify.
  3761      2. It does no longer proceed strictly from left to right but may also
  3762         rotate premises to achieve further simplification.
  3763      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  3764      old Asm_full_simp_tac in that it does not rotate premises.
  3765   2. The simplifier now knows a little bit about nat-arithmetic.
  3766 
  3767 * Classical reasoner: wrapper mechanism for the classical reasoner now
  3768 allows for selected deletion of wrappers, by introduction of names for
  3769 wrapper functionals.  This implies that addbefore, addSbefore,
  3770 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  3771 and that adding two tactics with the same name overwrites the first
  3772 one (emitting a warning).
  3773   type wrapper = (int -> tactic) -> (int -> tactic)
  3774   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  3775   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  3776   delWrapper, delSWrapper: claset *  string            -> claset
  3777   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  3778 
  3779 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  3780 semantics; addbefore now affects only the unsafe part of step_tac
  3781 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  3782 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  3783 by Force_tac;
  3784 
  3785 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  3786 compWrapper; added safe wrapper (and access functions for it);
  3787 
  3788 * HOL/split_all_tac is now much faster and fails if there is nothing
  3789 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  3790 and the names of the automatically generated variables have changed.
  3791 split_all_tac has moved within claset() from unsafe wrappers to safe
  3792 wrappers, which means that !!-bound variables are split much more
  3793 aggressively, and safe_tac and clarify_tac now split such variables.
  3794 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  3795 Note: the same holds for record_split_tac, which does the job of
  3796 split_all_tac for record fields.
  3797 
  3798 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  3799 permanently to the default simpset using Addsplits just like
  3800 Addsimps. They can be removed via Delsplits just like
  3801 Delsimps. Lower-case versions are also available.
  3802 
  3803 * HOL/Simplifier: The rule split_if is now part of the default
  3804 simpset. This means that the simplifier will eliminate all occurrences
  3805 of if-then-else in the conclusion of a goal. To prevent this, you can
  3806 either remove split_if completely from the default simpset by
  3807 `Delsplits [split_if]' or remove it in a specific call of the
  3808 simplifier using `... delsplits [split_if]'.  You can also add/delete
  3809 other case splitting rules to/from the default simpset: every datatype
  3810 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  3811 t is the name of the datatype).
  3812 
  3813 * Classical reasoner / Simplifier combination: new force_tac (and
  3814 derivatives Force_tac, force) combines rewriting and classical
  3815 reasoning (and whatever other tools) similarly to auto_tac, but is
  3816 aimed to solve the given subgoal completely.
  3817 
  3818 
  3819 *** General ***
  3820 
  3821 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  3822 and `goalw': the theory is no longer needed as an explicit argument -
  3823 the current theory context is used; assumptions are no longer returned
  3824 at the ML-level unless one of them starts with ==> or !!; it is
  3825 recommended to convert to these new commands using isatool fixgoal
  3826 (backup your sources first!);
  3827 
  3828 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  3829 the current theory context, and 'theory' to lookup stored theories;
  3830 
  3831 * new theory section 'locale' for declaring constants, assumptions and
  3832 definitions that have local scope;
  3833 
  3834 * new theory section 'nonterminals' for purely syntactic types;
  3835 
  3836 * new theory section 'setup' for generic ML setup functions
  3837 (e.g. package initialization);
  3838 
  3839 * the distribution now includes Isabelle icons: see
  3840 lib/logo/isabelle-{small,tiny}.xpm;
  3841 
  3842 * isatool install - install binaries with absolute references to
  3843 ISABELLE_HOME/bin;
  3844 
  3845 * isatool logo -- create instances of the Isabelle logo (as EPS);
  3846 
  3847 * print mode 'emacs' reserved for Isamode;
  3848 
  3849 * support multiple print (ast) translations per constant name;
  3850 
  3851 * theorems involving oracles are now printed with a suffixed [!];
  3852 
  3853 
  3854 *** HOL ***
  3855 
  3856 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  3857 
  3858 * HOL/inductive package reorganized and improved: now supports mutual
  3859 definitions such as
  3860 
  3861   inductive EVEN ODD
  3862     intrs
  3863       null "0 : EVEN"
  3864       oddI "n : EVEN ==> Suc n : ODD"
  3865       evenI "n : ODD ==> Suc n : EVEN"
  3866 
  3867 new theorem list "elims" contains an elimination rule for each of the
  3868 recursive sets; inductive definitions now handle disjunctive premises
  3869 correctly (also ZF);
  3870 
  3871 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  3872 "mutual_induct" no longer exists - the induction rule is always
  3873 contained in "induct";
  3874 
  3875 
  3876 * HOL/datatype package re-implemented and greatly improved: now
  3877 supports mutually recursive datatypes such as
  3878 
  3879   datatype
  3880     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  3881             | SUM ('a aexp) ('a aexp)
  3882             | DIFF ('a aexp) ('a aexp)
  3883             | NUM 'a
  3884   and
  3885     'a bexp = LESS ('a aexp) ('a aexp)
  3886             | AND ('a bexp) ('a bexp)
  3887             | OR ('a bexp) ('a bexp)
  3888 
  3889 as well as indirectly recursive datatypes such as
  3890 
  3891   datatype
  3892     ('a, 'b) term = Var 'a
  3893                   | App 'b ((('a, 'b) term) list)
  3894 
  3895 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  3896 induction on mutually / indirectly recursive datatypes.
  3897 
  3898 Primrec equations are now stored in theory and can be accessed via
  3899 <function_name>.simps.
  3900 
  3901 INCOMPATIBILITIES:
  3902 
  3903   - Theories using datatypes must now have theory Datatype as an
  3904     ancestor.
  3905   - The specific <typename>.induct_tac no longer exists - use the
  3906     generic induct_tac instead.
  3907   - natE has been renamed to nat.exhaust - use exhaust_tac
  3908     instead of res_inst_tac ... natE. Note that the variable
  3909     names in nat.exhaust differ from the names in natE, this
  3910     may cause some "fragile" proofs to fail.
  3911   - The theorems split_<typename>_case and split_<typename>_case_asm
  3912     have been renamed to <typename>.split and <typename>.split_asm.
  3913   - Since default sorts of type variables are now handled correctly,
  3914     some datatype definitions may have to be annotated with explicit
  3915     sort constraints.
  3916   - Primrec definitions no longer require function name and type
  3917     of recursive argument.
  3918 
  3919 Consider using isatool fixdatatype to adapt your theories and proof
  3920 scripts to the new package (backup your sources first!).
  3921 
  3922 
  3923 * HOL/record package: considerably improved implementation; now
  3924 includes concrete syntax for record types, terms, updates; theorems
  3925 for surjective pairing and splitting !!-bound record variables; proof
  3926 support is as follows:
  3927 
  3928   1) standard conversions (selectors or updates applied to record
  3929 constructor terms) are part of the standard simpset;
  3930 
  3931   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  3932 made part of standard simpset and claset via addIffs;
  3933 
  3934   3) a tactic for record field splitting (record_split_tac) is part of
  3935 the standard claset (addSWrapper);
  3936 
  3937 To get a better idea about these rules you may retrieve them via
  3938 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  3939 the name of your record type.
  3940 
  3941 The split tactic 3) conceptually simplifies by the following rule:
  3942 
  3943   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  3944 
  3945 Thus any record variable that is bound by meta-all will automatically
  3946 blow up into some record constructor term, consequently the
  3947 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  3948 solve record problems automatically.
  3949 
  3950 
  3951 * reorganized the main HOL image: HOL/Integ and String loaded by
  3952 default; theory Main includes everything;
  3953 
  3954 * automatic simplification of integer sums and comparisons, using cancellation;
  3955 
  3956 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  3957 
  3958 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  3959 
  3960 * many new identities for unions, intersections, set difference, etc.;
  3961 
  3962 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  3963 called split_if, split_split, split_sum_case and split_nat_case (to go
  3964 with add/delsplits);
  3965 
  3966 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  3967 (?x::unit) = (); this is made part of the default simpset, which COULD
  3968 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  3969 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  3970 unit_abs_eta_conv is added in order to counter the effect of
  3971 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  3972 %u.f();
  3973 
  3974 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  3975 makes more sense);
  3976 
  3977 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  3978   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  3979   disjointness reasoning but breaking a few old proofs.
  3980 
  3981 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  3982 to 'converse' from 'inverse' (for compatibility with ZF and some
  3983 literature);
  3984 
  3985 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  3986 the well-founded relation;
  3987 
  3988 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  3989     Compl A.  The "Compl" syntax remains available as input syntax for this
  3990     release ONLY.
  3991 
  3992 * HOL/Update: new theory of function updates:
  3993     f(a:=b) == %x. if x=a then b else f x
  3994 may also be iterated as in f(a:=b,c:=d,...);
  3995 
  3996 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  3997 
  3998 * HOL/List:
  3999   - new function list_update written xs[i:=v] that updates the i-th
  4000     list position. May also be iterated as in xs[i:=a,j:=b,...].
  4001   - new function `upt' written [i..j(] which generates the list
  4002     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  4003     bound write [i..j], which is a shorthand for [i..j+1(].
  4004   - new lexicographic orderings and corresponding wellfoundedness theorems.
  4005 
  4006 * HOL/Arith:
  4007   - removed 'pred' (predecessor) function;
  4008   - generalized some theorems about n-1;
  4009   - many new laws about "div" and "mod";
  4010   - new laws about greatest common divisors (see theory ex/Primes);
  4011 
  4012 * HOL/Relation: renamed the relational operator r^-1 "converse"
  4013 instead of "inverse";
  4014 
  4015 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  4016   of the multiset ordering;
  4017 
  4018 * directory HOL/Real: a construction of the reals using Dedekind cuts
  4019   (not included by default);
  4020 
  4021 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  4022 
  4023 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  4024   programs, i.e. different program variables may have different types.
  4025 
  4026 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4027   [previously, this check worked only if the rewrite rule was unconditional]
  4028   Now rew can involve either definitions or equalities (either == or =).
  4029 
  4030 
  4031 *** ZF ***
  4032 
  4033 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  4034   only the theorems proved on ZF.ML;
  4035 
  4036 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4037   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4038   disjointness reasoning but breaking a few old proofs.
  4039 
  4040 * ZF/Update: new theory of function updates
  4041     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  4042   may also be iterated as in f(a:=b,c:=d,...);
  4043 
  4044 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  4045 
  4046 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4047   [previously, this check worked only if the rewrite rule was unconditional]
  4048   Now rew can involve either definitions or equalities (either == or =).
  4049 
  4050 * case_tac provided for compatibility with HOL
  4051     (like the old excluded_middle_tac, but with subgoals swapped)
  4052 
  4053 
  4054 *** Internal programming interfaces ***
  4055 
  4056 * Pure: several new basic modules made available for general use, see
  4057 also src/Pure/README;
  4058 
  4059 * improved the theory data mechanism to support encapsulation (data
  4060 kind name replaced by private Object.kind, acting as authorization
  4061 key); new type-safe user interface via functor TheoryDataFun; generic
  4062 print_data function becomes basically useless;
  4063 
  4064 * removed global_names compatibility flag -- all theory declarations
  4065 are qualified by default;
  4066 
  4067 * module Pure/Syntax now offers quote / antiquote translation
  4068 functions (useful for Hoare logic etc. with implicit dependencies);
  4069 see HOL/ex/Antiquote for an example use;
  4070 
  4071 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  4072 cterm -> thm;
  4073 
  4074 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  4075 subgoal;
  4076 
  4077 * Display.print_goals function moved to Locale.print_goals;
  4078 
  4079 * standard print function for goals supports current_goals_markers
  4080 variable for marking begin of proof, end of proof, start of goal; the
  4081 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  4082 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  4083 for example;
  4084 
  4085 
  4086 
  4087 New in Isabelle98 (January 1998)
  4088 --------------------------------
  4089 
  4090 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4091 
  4092 * changed lexical syntax of terms / types: dots made part of long
  4093 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  4094 
  4095 * simpset (and claset) reference variable replaced by functions
  4096 simpset / simpset_ref;
  4097 
  4098 * no longer supports theory aliases (via merge) and non-trivial
  4099 implicit merge of thms' signatures;
  4100 
  4101 * most internal names of constants changed due to qualified names;
  4102 
  4103 * changed Pure/Sequence interface (see Pure/seq.ML);
  4104 
  4105 
  4106 *** General Changes ***
  4107 
  4108 * hierachically structured name spaces (for consts, types, axms, thms
  4109 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  4110 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  4111 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  4112 long_names for fully qualified output names; NOTE: ML programs
  4113 (special tactics, packages etc.) referring to internal names may have
  4114 to be adapted to cope with fully qualified names; in case of severe
  4115 backward campatibility problems try setting 'global_names' at compile
  4116 time to have enrything declared within a flat name space; one may also
  4117 fine tune name declarations in theories via the 'global' and 'local'
  4118 section;
  4119 
  4120 * reimplemented the implicit simpset and claset using the new anytype
  4121 data filed in signatures; references simpset:simpset ref etc. are
  4122 replaced by functions simpset:unit->simpset and
  4123 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  4124 to patch your ML files accordingly;
  4125 
  4126 * HTML output now includes theory graph data for display with Java
  4127 applet or isatool browser; data generated automatically via isatool
  4128 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  4129 
  4130 * defs may now be conditional; improved rewrite_goals_tac to handle
  4131 conditional equations;
  4132 
  4133 * defs now admits additional type arguments, using TYPE('a) syntax;
  4134 
  4135 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  4136 creates a new theory node; implicit merge of thms' signatures is
  4137 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  4138 transfer:theory->thm->thm in (rare) cases;
  4139 
  4140 * improved handling of draft signatures / theories; draft thms (and
  4141 ctyps, cterms) are automatically promoted to real ones;
  4142 
  4143 * slightly changed interfaces for oracles: admit many per theory, named
  4144 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  4145 
  4146 * print_goals: optional output of const types (set show_consts and
  4147 show_types);
  4148 
  4149 * improved output of warnings (###) and errors (***);
  4150 
  4151 * subgoal_tac displays a warning if the new subgoal has type variables;
  4152 
  4153 * removed old README and Makefiles;
  4154 
  4155 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  4156 
  4157 * removed obsolete init_pps and init_database;
  4158 
  4159 * deleted the obsolete tactical STATE, which was declared by
  4160     fun STATE tacfun st = tacfun st st;
  4161 
  4162 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  4163 (which abbreviates $HOME);
  4164 
  4165 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  4166 use isatool fixseq to adapt your ML programs (this works for fully
  4167 qualified references to the Sequence structure only!);
  4168 
  4169 * use_thy no longer requires writable current directory; it always
  4170 reloads .ML *and* .thy file, if either one is out of date;
  4171 
  4172 
  4173 *** Classical Reasoner ***
  4174 
  4175 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  4176 tactics that use classical reasoning to simplify a subgoal without
  4177 splitting it into several subgoals;
  4178 
  4179 * Safe_tac: like safe_tac but uses the default claset;
  4180 
  4181 
  4182 *** Simplifier ***
  4183 
  4184 * added simplification meta rules:
  4185     (asm_)(full_)simplify: simpset -> thm -> thm;
  4186 
  4187 * simplifier.ML no longer part of Pure -- has to be loaded by object
  4188 logics (again);
  4189 
  4190 * added prems argument to simplification procedures;
  4191 
  4192 * HOL, FOL, ZF: added infix function `addsplits':
  4193   instead of `<simpset> setloop (split_tac <thms>)'
  4194   you can simply write `<simpset> addsplits <thms>'
  4195 
  4196 
  4197 *** Syntax ***
  4198 
  4199 * TYPE('a) syntax for type reflection terms;
  4200 
  4201 * no longer handles consts with name "" -- declare as 'syntax' instead;
  4202 
  4203 * pretty printer: changed order of mixfix annotation preference (again!);
  4204 
  4205 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  4206 
  4207 
  4208 *** HOL ***
  4209 
  4210 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4211   with `addloop' of the simplifier to faciliate case splitting in premises.
  4212 
  4213 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  4214 
  4215 * HOL/Auth: new protocol proofs including some for the Internet
  4216   protocol TLS;
  4217 
  4218 * HOL/Map: new theory of `maps' a la VDM;
  4219 
  4220 * HOL/simplifier: simplification procedures nat_cancel_sums for
  4221 cancelling out common nat summands from =, <, <= (in)equalities, or
  4222 differences; simplification procedures nat_cancel_factor for
  4223 cancelling common factor from =, <, <= (in)equalities over natural
  4224 sums; nat_cancel contains both kinds of procedures, it is installed by
  4225 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  4226 
  4227 * HOL/simplifier: terms of the form
  4228   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  4229   are rewritten to
  4230   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  4231   and those of the form
  4232   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  4233   are rewritten to
  4234   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  4235 
  4236 * HOL/datatype
  4237   Each datatype `t' now comes with a theorem `split_t_case' of the form
  4238 
  4239   P(t_case f1 ... fn x) =
  4240      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  4241         ...
  4242        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  4243      )
  4244 
  4245   and a theorem `split_t_case_asm' of the form
  4246 
  4247   P(t_case f1 ... fn x) =
  4248     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  4249         ...
  4250        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  4251      )
  4252   which can be added to a simpset via `addsplits'. The existing theorems
  4253   expand_list_case and expand_option_case have been renamed to
  4254   split_list_case and split_option_case.
  4255 
  4256 * HOL/Arithmetic:
  4257   - `pred n' is automatically converted to `n-1'.
  4258     Users are strongly encouraged not to use `pred' any longer,
  4259     because it will disappear altogether at some point.
  4260   - Users are strongly encouraged to write "0 < n" rather than
  4261     "n ~= 0". Theorems and proof tools have been modified towards this
  4262     `standard'.
  4263 
  4264 * HOL/Lists:
  4265   the function "set_of_list" has been renamed "set" (and its theorems too);
  4266   the function "nth" now takes its arguments in the reverse order and
  4267   has acquired the infix notation "!" as in "xs!n".
  4268 
  4269 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  4270 
  4271 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  4272   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  4273 
  4274 * HOL/record: extensible records with schematic structural subtyping
  4275 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  4276 still lacks various theorems and concrete record syntax;
  4277 
  4278 
  4279 *** HOLCF ***
  4280 
  4281 * removed "axioms" and "generated by" sections;
  4282 
  4283 * replaced "ops" section by extended "consts" section, which is capable of
  4284   handling the continuous function space "->" directly;
  4285 
  4286 * domain package:
  4287   . proves theorems immediately and stores them in the theory,
  4288   . creates hierachical name space,
  4289   . now uses normal mixfix annotations (instead of cinfix...),
  4290   . minor changes to some names and values (for consistency),
  4291   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  4292   . separator between mutual domain defs: changed "," to "and",
  4293   . improved handling of sort constraints;  now they have to
  4294     appear on the left-hand side of the equations only;
  4295 
  4296 * fixed LAM <x,y,zs>.b syntax;
  4297 
  4298 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  4299 adm (%x. P (t x)), where P is chainfinite and t continuous;
  4300 
  4301 
  4302 *** FOL and ZF ***
  4303 
  4304 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4305   with `addloop' of the simplifier to faciliate case splitting in premises.
  4306 
  4307 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  4308 in HOL, they strip ALL and --> from proved theorems;
  4309 
  4310 
  4311 
  4312 New in Isabelle94-8 (May 1997)
  4313 ------------------------------
  4314 
  4315 *** General Changes ***
  4316 
  4317 * new utilities to build / run / maintain Isabelle etc. (in parts
  4318 still somewhat experimental); old Makefiles etc. still functional;
  4319 
  4320 * new 'Isabelle System Manual';
  4321 
  4322 * INSTALL text, together with ./configure and ./build scripts;
  4323 
  4324 * reimplemented type inference for greater efficiency, better error
  4325 messages and clean internal interface;
  4326 
  4327 * prlim command for dealing with lots of subgoals (an easier way of
  4328 setting goals_limit);
  4329 
  4330 
  4331 *** Syntax ***
  4332 
  4333 * supports alternative (named) syntax tables (parser and pretty
  4334 printer); internal interface is provided by add_modesyntax(_i);
  4335 
  4336 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  4337 be used in conjunction with the Isabelle symbol font; uses the
  4338 "symbols" syntax table;
  4339 
  4340 * added token_translation interface (may translate name tokens in
  4341 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  4342 the current print_mode); IMPORTANT: user print translation functions
  4343 are responsible for marking newly introduced bounds
  4344 (Syntax.mark_boundT);
  4345 
  4346 * token translations for modes "xterm" and "xterm_color" that display
  4347 names in bold, underline etc. or colors (which requires a color
  4348 version of xterm);
  4349 
  4350 * infixes may now be declared with names independent of their syntax;
  4351 
  4352 * added typed_print_translation (like print_translation, but may
  4353 access type of constant);
  4354 
  4355 
  4356 *** Classical Reasoner ***
  4357 
  4358 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  4359 some limitations.  Blast_tac...
  4360   + ignores addss, addbefore, addafter; this restriction is intrinsic
  4361   + ignores elimination rules that don't have the correct format
  4362         (the conclusion MUST be a formula variable)
  4363   + ignores types, which can make HOL proofs fail
  4364   + rules must not require higher-order unification, e.g. apply_type in ZF
  4365     [message "Function Var's argument not a bound variable" relates to this]
  4366   + its proof strategy is more general but can actually be slower
  4367 
  4368 * substitution with equality assumptions no longer permutes other
  4369 assumptions;
  4370 
  4371 * minor changes in semantics of addafter (now called addaltern); renamed
  4372 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  4373 (and access functions for it);
  4374 
  4375 * improved combination of classical reasoner and simplifier:
  4376   + functions for handling clasimpsets
  4377   + improvement of addss: now the simplifier is called _after_ the
  4378     safe steps.
  4379   + safe variant of addss called addSss: uses safe simplifications
  4380     _during_ the safe steps. It is more complete as it allows multiple
  4381     instantiations of unknowns (e.g. with slow_tac).
  4382 
  4383 *** Simplifier ***
  4384 
  4385 * added interface for simplification procedures (functions that
  4386 produce *proven* rewrite rules on the fly, depending on current
  4387 redex);
  4388 
  4389 * ordering on terms as parameter (used for ordered rewriting);
  4390 
  4391 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  4392 
  4393 * the solver is now split into a safe and an unsafe part.
  4394 This should be invisible for the normal user, except that the
  4395 functions setsolver and addsolver have been renamed to setSolver and
  4396 addSolver; added safe_asm_full_simp_tac;
  4397 
  4398 
  4399 *** HOL ***
  4400 
  4401 * a generic induction tactic `induct_tac' which works for all datatypes and
  4402 also for type `nat';
  4403 
  4404 * a generic case distinction tactic `exhaust_tac' which works for all
  4405 datatypes and also for type `nat';
  4406 
  4407 * each datatype comes with a function `size';
  4408 
  4409 * patterns in case expressions allow tuple patterns as arguments to
  4410 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  4411 
  4412 * primrec now also works with type nat;
  4413 
  4414 * recdef: a new declaration form, allows general recursive functions to be
  4415 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  4416 
  4417 * the constant for negation has been renamed from "not" to "Not" to
  4418 harmonize with FOL, ZF, LK, etc.;
  4419 
  4420 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  4421 infinite lists;
  4422 
  4423 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  4424 
  4425 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  4426 problems in commutative rings, using axiomatic type classes for + and *;
  4427 
  4428 * more examples in HOL/MiniML and HOL/Auth;
  4429 
  4430 * more default rewrite rules for quantifiers, union/intersection;
  4431 
  4432 * a new constant `arbitrary == @x.False';
  4433 
  4434 * HOLCF/IOA replaces old HOL/IOA;
  4435 
  4436 * HOLCF changes: derived all rules and arities
  4437   + axiomatic type classes instead of classes
  4438   + typedef instead of faking type definitions
  4439   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  4440   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  4441   + eliminated the types void, one, tr
  4442   + use unit lift and bool lift (with translations) instead of one and tr
  4443   + eliminated blift from Lift3.thy (use Def instead of blift)
  4444   all eliminated rules are derived as theorems --> no visible changes ;
  4445 
  4446 
  4447 *** ZF ***
  4448 
  4449 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  4450 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  4451 as ZF_cs addSIs [equalityI];
  4452 
  4453 
  4454 
  4455 New in Isabelle94-7 (November 96)
  4456 ---------------------------------
  4457 
  4458 * allowing negative levels (as offsets) in prlev and choplev;
  4459 
  4460 * super-linear speedup for large simplifications;
  4461 
  4462 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  4463 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  4464 FAIL); can suppress it using the command Delsimps (ex_simps @
  4465 all_simps); De Morgan laws are also now included, by default;
  4466 
  4467 * improved printing of ==>  :  ~:
  4468 
  4469 * new object-logic "Sequents" adds linear logic, while replacing LK
  4470 and Modal (thanks to Sara Kalvala);
  4471 
  4472 * HOL/Auth: correctness proofs for authentication protocols;
  4473 
  4474 * HOL: new auto_tac combines rewriting and classical reasoning (many
  4475 examples on HOL/Auth);
  4476 
  4477 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  4478 the rewriter and classical reasoner simultaneously;
  4479 
  4480 * function uresult no longer returns theorems in "standard" format;
  4481 regain previous version by: val uresult = standard o uresult;
  4482 
  4483 
  4484 
  4485 New in Isabelle94-6
  4486 -------------------
  4487 
  4488 * oracles -- these establish an interface between Isabelle and trusted
  4489 external reasoners, which may deliver results as theorems;
  4490 
  4491 * proof objects (in particular record all uses of oracles);
  4492 
  4493 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  4494 
  4495 * "constdefs" section in theory files;
  4496 
  4497 * "primrec" section (HOL) no longer requires names;
  4498 
  4499 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  4500 
  4501 
  4502 
  4503 New in Isabelle94-5
  4504 -------------------
  4505 
  4506 * reduced space requirements;
  4507 
  4508 * automatic HTML generation from theories;
  4509 
  4510 * theory files no longer require "..." (quotes) around most types;
  4511 
  4512 * new examples, including two proofs of the Church-Rosser theorem;
  4513 
  4514 * non-curried (1994) version of HOL is no longer distributed;
  4515 
  4516 
  4517 
  4518 New in Isabelle94-4
  4519 -------------------
  4520 
  4521 * greatly reduced space requirements;
  4522 
  4523 * theory files (.thy) no longer require \...\ escapes at line breaks;
  4524 
  4525 * searchable theorem database (see the section "Retrieving theorems" on
  4526 page 8 of the Reference Manual);
  4527 
  4528 * new examples, including Grabczewski's monumental case study of the
  4529 Axiom of Choice;
  4530 
  4531 * The previous version of HOL renamed to Old_HOL;
  4532 
  4533 * The new version of HOL (previously called CHOL) uses a curried syntax
  4534 for functions.  Application looks like f a b instead of f(a,b);
  4535 
  4536 * Mutually recursive inductive definitions finally work in HOL;
  4537 
  4538 * In ZF, pattern-matching on tuples is now available in all abstractions and
  4539 translates to the operator "split";
  4540 
  4541 
  4542 
  4543 New in Isabelle94-3
  4544 -------------------
  4545 
  4546 * new infix operator, addss, allowing the classical reasoner to
  4547 perform simplification at each step of its search.  Example:
  4548         fast_tac (cs addss ss)
  4549 
  4550 * a new logic, CHOL, the same as HOL, but with a curried syntax
  4551 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  4552 look like (a,b) instead of <a,b>;
  4553 
  4554 * PLEASE NOTE: CHOL will eventually replace HOL!
  4555 
  4556 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  4557 It translates to the operator "split".  A new theory of integers is available;
  4558 
  4559 * In ZF, integer numerals now denote two's-complement binary integers.
  4560 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  4561 
  4562 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  4563 of the Axiom of Choice;
  4564 
  4565 
  4566 
  4567 New in Isabelle94-2
  4568 -------------------
  4569 
  4570 * Significantly faster resolution;
  4571 
  4572 * the different sections in a .thy file can now be mixed and repeated
  4573 freely;
  4574 
  4575 * Database of theorems for FOL, HOL and ZF.  New
  4576 commands including qed, qed_goal and bind_thm store theorems in the database.
  4577 
  4578 * Simple database queries: return a named theorem (get_thm) or all theorems of
  4579 a given theory (thms_of), or find out what theory a theorem was proved in
  4580 (theory_of_thm);
  4581 
  4582 * Bugs fixed in the inductive definition and datatype packages;
  4583 
  4584 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  4585 and HOL_dup_cs obsolete;
  4586 
  4587 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  4588 have been removed;
  4589 
  4590 * Simpler definition of function space in ZF;
  4591 
  4592 * new results about cardinal and ordinal arithmetic in ZF;
  4593 
  4594 * 'subtype' facility in HOL for introducing new types as subsets of existing
  4595 types;
  4596 
  4597 
  4598 $Id$