NEWS
author huffman
Tue Dec 12 17:15:42 2006 +0100 (2006-12-12)
changeset 21791 367477e8458b
parent 21735 0c65e072f4be
child 21879 a3efbae45735
permissions -rw-r--r--
additions to HOL-Complex
     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/table:
   772 
   773 Function `...tab.foldl` removed.
   774 INCOMPATIBILITY: use `...tabfold` instead
   775 
   776 * Pure/library:
   777 
   778 `gen_rem(s)` abandoned in favour of `remove` / `subtract`.
   779 INCOMPATIBILITY:
   780 rewrite "gen_rem eq (xs, x)" to "remove (eq o swap) x xs"
   781 rewrite "gen_rems eq (xs, ys)" to "subtract (eq o swap) ys xs"
   782 drop "swap" if "eq" is symmetric.
   783 
   784 * Pure/library:
   785 
   786 infixes `ins` `ins_string` `ins_int` have been abandoned in favour of `insert`.
   787 INCOMPATIBILITY: rewrite "x ins(_...) xs" to "insert (op =) x xs"
   788 
   789 * Pure/General/susp.ML:
   790 
   791 New module for delayed evaluations.
   792 
   793 * Pure/library:
   794 
   795 Semantically identical functions "equal_list" and "eq_list" have been
   796 unified to "eq_list".
   797 
   798 * Pure/library:
   799 
   800   val burrow: ('a list -> 'b list) -> 'a list list -> 'b list list
   801   val fold_burrow: ('a list -> 'c -> 'b list * 'd) -> 'a list list -> 'c -> 'b list list * 'd
   802 
   803 The semantics of "burrow" is: "take a function with *simulatanously*
   804 transforms a list of value, and apply it *simulatanously* to a list of
   805 list of values of the appropriate type". Confer this with "map" which
   806 would *not* apply its argument function simulatanously but in
   807 sequence. "fold_burrow" has an additional context.
   808 
   809 Both actually avoid the usage of "unflat" since they hide away
   810 "unflat" from the user.
   811 
   812 * Pure/library: functions map2 and fold2 with curried syntax for
   813 simultanous mapping and folding:
   814 
   815     val map2: ('a -> 'b -> 'c) -> 'a list -> 'b list -> 'c list
   816     val fold2: ('a -> 'b -> 'c -> 'c) -> 'a list -> 'b list -> 'c -> 'c
   817 
   818 * Pure/library: indexed lists - some functions in the Isabelle library
   819 treating lists over 'a as finite mappings from [0...n] to 'a have been
   820 given more convenient names and signatures reminiscent of similar
   821 functions for alists, tables, etc:
   822 
   823   val nth: 'a list -> int -> 'a 
   824   val nth_map: int -> ('a -> 'a) -> 'a list -> 'a list
   825   val fold_index: (int * 'a -> 'b -> 'b) -> 'a list -> 'b -> 'b
   826 
   827 Note that fold_index starts counting at index 0, not 1 like foldln
   828 used to.
   829 
   830 * Pure/library: general ``divide_and_conquer'' combinator on lists.
   831 
   832 * Pure/General/name_mangler.ML provides a functor for generic name
   833 mangling (bijective mapping from expression values to strings).
   834 
   835 * Pure/General/rat.ML implements rational numbers.
   836 
   837 * Pure/General/table.ML: the join operations now works via exceptions
   838 DUP/SAME instead of type option.  This is simpler in simple cases, and
   839 admits slightly more efficient complex applications.
   840 
   841 * Pure: datatype Context.generic joins theory/Proof.context and
   842 provides some facilities for code that works in either kind of
   843 context, notably GenericDataFun for uniform theory and proof data.
   844 
   845 * Pure: 'advanced' translation functions (parse_translation etc.) now
   846 use Context.generic instead of just theory.
   847 
   848 * Pure: simplified internal attribute type, which is now always
   849 Context.generic * thm -> Context.generic * thm.  Global (theory)
   850 vs. local (Proof.context) attributes have been discontinued, while
   851 minimizing code duplication.  Thm.rule_attribute and
   852 Thm.declaration_attribute build canonical attributes; see also
   853 structure Context for further operations on Context.generic, notably
   854 GenericDataFun.  INCOMPATIBILITY, need to adapt attribute type
   855 declarations and definitions.
   856 
   857 * Pure/kernel: consts certification ignores sort constraints given in
   858 signature declarations.  (This information is not relevant to the
   859 logic, but only for type inference.)  IMPORTANT INTERNAL CHANGE.
   860 
   861 * Pure: axiomatic type classes are now purely definitional, with
   862 explicit proofs of class axioms and super class relations performed
   863 internally.  See Pure/axclass.ML for the main internal interfaces --
   864 notably AxClass.define_class supercedes AxClass.add_axclass, and
   865 AxClass.axiomatize_class/classrel/arity supercede
   866 Sign.add_classes/classrel/arities.
   867 
   868 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
   869 global/local versions on theory vs. Proof.context have been
   870 discontinued; Attrib.syntax and Method.syntax have been adapted
   871 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
   872 attributes, methods, etc.
   873 
   874 * Pure: several functions of signature "... -> theory -> theory * ..."
   875 have been reoriented to "... -> theory -> ... * theory" in order to
   876 allow natural usage in combination with the ||>, ||>>, |-> and
   877 fold_map combinators.
   878 
   879 * Pure: official theorem names (closed derivations) and additional
   880 comments (tags) are now strictly separate.  Name hints -- which are
   881 maintained as tags -- may be attached any time without affecting the
   882 derivation.
   883 
   884 * Pure: primitive rule lift_rule now takes goal cterm instead of an
   885 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
   886 achieve the old behaviour.
   887 
   888 * Pure: the "Goal" constant is now called "prop", supporting a
   889 slightly more general idea of ``protecting'' meta-level rule
   890 statements.
   891 
   892 * Pure: Logic.(un)varify only works in a global context, which is now
   893 enforced instead of silently assumed.  INCOMPATIBILITY, may use
   894 Logic.legacy_(un)varify as temporary workaround.
   895 
   896 * Pure: structure Name provides scalable operations for generating
   897 internal variable names, notably Name.variants etc.  This replaces
   898 some popular functions from term.ML:
   899 
   900   Term.variant		->  Name.variant
   901   Term.variantlist	->  Name.variant_list  (*canonical argument order*)
   902   Term.invent_names	->  Name.invent_list
   903 
   904 Note that low-level renaming rarely occurs in new code -- operations
   905 from structure Variable are used instead (see below).
   906 
   907 * Pure: structure Variable provides fundamental operations for proper
   908 treatment of fixed/schematic variables in a context.  For example,
   909 Variable.import introduces fixes for schematics of given facts and
   910 Variable.export reverses the effect (up to renaming) -- this replaces
   911 various freeze_thaw operations.
   912 
   913 * Pure: structure Goal provides simple interfaces for
   914 init/conclude/finish and tactical prove operations (replacing former
   915 Tactic.prove).  Goal.prove is the canonical way to prove results
   916 within a given context; Goal.prove_global is a degraded version for
   917 theory level goals, including a global Drule.standard.  Note that
   918 OldGoals.prove_goalw_cterm has long been obsolete, since it is
   919 ill-behaved in a local proof context (e.g. with local fixes/assumes or
   920 in a locale context).
   921 
   922 * Isar: simplified treatment of user-level errors, using exception
   923 ERROR of string uniformly.  Function error now merely raises ERROR,
   924 without any side effect on output channels.  The Isar toplevel takes
   925 care of proper display of ERROR exceptions.  ML code may use plain
   926 handle/can/try; cat_error may be used to concatenate errors like this:
   927 
   928   ... handle ERROR msg => cat_error msg "..."
   929 
   930 Toplevel ML code (run directly or through the Isar toplevel) may be
   931 embedded into the Isar toplevel with exception display/debug like
   932 this:
   933 
   934   Isar.toplevel (fn () => ...)
   935 
   936 INCOMPATIBILITY, removed special transform_error facilities, removed
   937 obsolete variants of user-level exceptions (ERROR_MESSAGE,
   938 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
   939 -- use plain ERROR instead.
   940 
   941 * Isar: theory setup now has type (theory -> theory), instead of a
   942 list.  INCOMPATIBILITY, may use #> to compose setup functions.
   943 
   944 * Isar: installed ML toplevel pretty printer for type Proof.context,
   945 subject to ProofContext.debug/verbose flags.
   946 
   947 * Isar: Toplevel.theory_to_proof admits transactions that modify the
   948 theory before entering a proof state.  Transactions now always see a
   949 quasi-functional intermediate checkpoint, both in interactive and
   950 batch mode.
   951 
   952 * Simplifier: the simpset of a running simplification process now
   953 contains a proof context (cf. Simplifier.the_context), which is the
   954 very context that the initial simpset has been retrieved from (by
   955 simpset_of/local_simpset_of).  Consequently, all plug-in components
   956 (solver, looper etc.) may depend on arbitrary proof data.
   957 
   958 * Simplifier.inherit_context inherits the proof context (plus the
   959 local bounds) of the current simplification process; any simproc
   960 etc. that calls the Simplifier recursively should do this!  Removed
   961 former Simplifier.inherit_bounds, which is already included here --
   962 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
   963 specify an explicit context using Simplifier.context/theory_context.
   964 
   965 * Simplifier/Classical Reasoner: more abstract interfaces
   966 change_simpset/claset for modifying the simpset/claset reference of a
   967 theory; raw versions simpset/claset_ref etc. have been discontinued --
   968 INCOMPATIBILITY.
   969 
   970 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
   971 "Trueprop" etc.
   972 
   973 
   974 *** System ***
   975 
   976 * settings: ML_IDENTIFIER -- which is appended to user specific heap
   977 locations -- now includes the Isabelle version identifier as well.
   978 This simplifies use of multiple Isabelle installations.
   979 
   980 * isabelle-process: option -S (secure mode) disables some critical
   981 operations, notably runtime compilation and evaluation of ML source
   982 code.
   983 
   984 
   985 New in Isabelle2005 (October 2005)
   986 ----------------------------------
   987 
   988 *** General ***
   989 
   990 * Theory headers: the new header syntax for Isar theories is
   991 
   992   theory <name>
   993   imports <theory1> ... <theoryN>
   994   uses <file1> ... <fileM>
   995   begin
   996 
   997 where the 'uses' part is optional.  The previous syntax
   998 
   999   theory <name> = <theory1> + ... + <theoryN>:
  1000 
  1001 will disappear in the next release.  Use isatool fixheaders to convert
  1002 existing theory files.  Note that there is no change in ancient
  1003 non-Isar theories now, but these will disappear soon.
  1004 
  1005 * Theory loader: parent theories can now also be referred to via
  1006 relative and absolute paths.
  1007 
  1008 * Command 'find_theorems' searches for a list of criteria instead of a
  1009 list of constants. Known criteria are: intro, elim, dest, name:string,
  1010 simp:term, and any term. Criteria can be preceded by '-' to select
  1011 theorems that do not match. Intro, elim, dest select theorems that
  1012 match the current goal, name:s selects theorems whose fully qualified
  1013 name contain s, and simp:term selects all simplification rules whose
  1014 lhs match term.  Any other term is interpreted as pattern and selects
  1015 all theorems matching the pattern. Available in ProofGeneral under
  1016 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  1017 
  1018   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  1019 
  1020 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  1021 matching the current goal as introduction rule and not having "HOL."
  1022 in their name (i.e. not being defined in theory HOL).
  1023 
  1024 * Command 'thms_containing' has been discontinued in favour of
  1025 'find_theorems'; INCOMPATIBILITY.
  1026 
  1027 * Communication with Proof General is now 8bit clean, which means that
  1028 Unicode text in UTF-8 encoding may be used within theory texts (both
  1029 formal and informal parts).  Cf. option -U of the Isabelle Proof
  1030 General interface.  Here are some simple examples (cf. src/HOL/ex):
  1031 
  1032   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  1033   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  1034 
  1035 * Improved efficiency of the Simplifier and, to a lesser degree, the
  1036 Classical Reasoner.  Typical big applications run around 2 times
  1037 faster.
  1038 
  1039 
  1040 *** Document preparation ***
  1041 
  1042 * Commands 'display_drafts' and 'print_drafts' perform simple output
  1043 of raw sources.  Only those symbols that do not require additional
  1044 LaTeX packages (depending on comments in isabellesym.sty) are
  1045 displayed properly, everything else is left verbatim.  isatool display
  1046 and isatool print are used as front ends (these are subject to the
  1047 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  1048 
  1049 * Command tags control specific markup of certain regions of text,
  1050 notably folding and hiding.  Predefined tags include "theory" (for
  1051 theory begin and end), "proof" for proof commands, and "ML" for
  1052 commands involving ML code; the additional tags "visible" and
  1053 "invisible" are unused by default.  Users may give explicit tag
  1054 specifications in the text, e.g. ''by %invisible (auto)''.  The
  1055 interpretation of tags is determined by the LaTeX job during document
  1056 preparation: see option -V of isatool usedir, or options -n and -t of
  1057 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  1058 \isadroptag.
  1059 
  1060 Several document versions may be produced at the same time via isatool
  1061 usedir (the generated index.html will link all of them).  Typical
  1062 specifications include ''-V document=theory,proof,ML'' to present
  1063 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  1064 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  1065 these parts without any formal replacement text.  The Isabelle site
  1066 default settings produce ''document'' and ''outline'' versions as
  1067 specified above.
  1068 
  1069 * Several new antiquotations:
  1070 
  1071   @{term_type term} prints a term with its type annotated;
  1072 
  1073   @{typeof term} prints the type of a term;
  1074 
  1075   @{const const} is the same as @{term const}, but checks that the
  1076   argument is a known logical constant;
  1077 
  1078   @{term_style style term} and @{thm_style style thm} print a term or
  1079   theorem applying a "style" to it
  1080 
  1081   @{ML text}
  1082 
  1083 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  1084 definitions, equations, inequations etc., 'concl' printing only the
  1085 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  1086 to print the specified premise.  TermStyle.add_style provides an ML
  1087 interface for introducing further styles.  See also the "LaTeX Sugar"
  1088 document practical applications.  The ML antiquotation prints
  1089 type-checked ML expressions verbatim.
  1090 
  1091 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  1092 and 'text' support optional locale specification '(in loc)', which
  1093 specifies the default context for interpreting antiquotations.  For
  1094 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  1095 
  1096 * Option 'locale=NAME' of antiquotations specifies an alternative
  1097 context interpreting the subsequent argument.  For example: @{thm
  1098 [locale=lattice] inf_assoc}.
  1099 
  1100 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  1101 a proof context.
  1102 
  1103 * Proper output of antiquotations for theory commands involving a
  1104 proof context (such as 'locale' or 'theorem (in loc) ...').
  1105 
  1106 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  1107 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  1108 
  1109 * isatool usedir: new option -C (default true) controls whether option
  1110 -D should include a copy of the original document directory; -C false
  1111 prevents unwanted effects such as copying of administrative CVS data.
  1112 
  1113 
  1114 *** Pure ***
  1115 
  1116 * Considerably improved version of 'constdefs' command.  Now performs
  1117 automatic type-inference of declared constants; additional support for
  1118 local structure declarations (cf. locales and HOL records), see also
  1119 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  1120 sequential dependencies of definitions within a single 'constdefs'
  1121 section; moreover, the declared name needs to be an identifier.  If
  1122 all fails, consider to fall back on 'consts' and 'defs' separately.
  1123 
  1124 * Improved indexed syntax and implicit structures.  First of all,
  1125 indexed syntax provides a notational device for subscripted
  1126 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  1127 expressions.  Secondly, in a local context with structure
  1128 declarations, number indexes \<^sub>n or the empty index (default
  1129 number 1) refer to a certain fixed variable implicitly; option
  1130 show_structs controls printing of implicit structures.  Typical
  1131 applications of these concepts involve record types and locales.
  1132 
  1133 * New command 'no_syntax' removes grammar declarations (and
  1134 translations) resulting from the given syntax specification, which is
  1135 interpreted in the same manner as for the 'syntax' command.
  1136 
  1137 * 'Advanced' translation functions (parse_translation etc.) may depend
  1138 on the signature of the theory context being presently used for
  1139 parsing/printing, see also isar-ref manual.
  1140 
  1141 * Improved 'oracle' command provides a type-safe interface to turn an
  1142 ML expression of type theory -> T -> term into a primitive rule of
  1143 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  1144 is already included here); see also FOL/ex/IffExample.thy;
  1145 INCOMPATIBILITY.
  1146 
  1147 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  1148 before); "cI" is no longer bound, use "c.intro" instead.
  1149 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  1150 axclasses vs. locales.
  1151 
  1152 * Improved internal renaming of symbolic identifiers -- attach primes
  1153 instead of base 26 numbers.
  1154 
  1155 * New flag show_question_marks controls printing of leading question
  1156 marks in schematic variable names.
  1157 
  1158 * In schematic variable names, *any* symbol following \<^isub> or
  1159 \<^isup> is now treated as part of the base name.  For example, the
  1160 following works without printing of awkward ".0" indexes:
  1161 
  1162   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  1163     by simp
  1164 
  1165 * Inner syntax includes (*(*nested*) comments*).
  1166 
  1167 * Pretty printer now supports unbreakable blocks, specified in mixfix
  1168 annotations as "(00...)".
  1169 
  1170 * Clear separation of logical types and nonterminals, where the latter
  1171 may only occur in 'syntax' specifications or type abbreviations.
  1172 Before that distinction was only partially implemented via type class
  1173 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  1174 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  1175 exotic syntax specifications may require further adaption
  1176 (e.g. Cube/Cube.thy).
  1177 
  1178 * Removed obsolete type class "logic", use the top sort {} instead.
  1179 Note that non-logical types should be declared as 'nonterminals'
  1180 rather than 'types'.  INCOMPATIBILITY for new object-logic
  1181 specifications.
  1182 
  1183 * Attributes 'induct' and 'cases': type or set names may now be
  1184 locally fixed variables as well.
  1185 
  1186 * Simplifier: can now control the depth to which conditional rewriting
  1187 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  1188 Limit.
  1189 
  1190 * Simplifier: simplification procedures may now take the current
  1191 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  1192 interface), which is very useful for calling the Simplifier
  1193 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  1194 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  1195 low-level mk_simproc no longer applies Logic.varify internally, to
  1196 allow for use in a context of fixed variables.
  1197 
  1198 * thin_tac now works even if the assumption being deleted contains !!
  1199 or ==>.  More generally, erule now works even if the major premise of
  1200 the elimination rule contains !! or ==>.
  1201 
  1202 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  1203 
  1204 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  1205 from Pure, which contains all common declarations already.  Both
  1206 theories are defined via plain Isabelle/Isar .thy files.
  1207 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  1208 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  1209 use isatool fixcpure to adapt your theory and ML sources.
  1210 
  1211 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  1212 selections of theorems in named facts via index ranges.
  1213 
  1214 * 'print_theorems': in theory mode, really print the difference
  1215 wrt. the last state (works for interactive theory development only),
  1216 in proof mode print all local facts (cf. 'print_facts');
  1217 
  1218 * 'hide': option '(open)' hides only base names.
  1219 
  1220 * More efficient treatment of intermediate checkpoints in interactive
  1221 theory development.
  1222 
  1223 * Code generator is now invoked via code_module (incremental code
  1224 generation) and code_library (modular code generation, ML structures
  1225 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  1226 must be quoted when used as identifiers.
  1227 
  1228 * New 'value' command for reading, evaluating and printing terms using
  1229 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  1230 quoted when used as identifier.
  1231 
  1232 
  1233 *** Locales ***
  1234 
  1235 * New commands for the interpretation of locale expressions in
  1236 theories (1), locales (2) and proof contexts (3).  These generate
  1237 proof obligations from the expression specification.  After the
  1238 obligations have been discharged, theorems of the expression are added
  1239 to the theory, target locale or proof context.  The synopsis of the
  1240 commands is a follows:
  1241 
  1242   (1) interpretation expr inst
  1243   (2) interpretation target < expr
  1244   (3) interpret expr inst
  1245 
  1246 Interpretation in theories and proof contexts require a parameter
  1247 instantiation of terms from the current context.  This is applied to
  1248 specifications and theorems of the interpreted expression.
  1249 Interpretation in locales only permits parameter renaming through the
  1250 locale expression.  Interpretation is smart in that interpretations
  1251 that are active already do not occur in proof obligations, neither are
  1252 instantiated theorems stored in duplicate.  Use 'print_interps' to
  1253 inspect active interpretations of a particular locale.  For details,
  1254 see the Isar Reference manual.  Examples can be found in
  1255 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  1256 
  1257 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  1258 'interpret' instead.
  1259 
  1260 * New context element 'constrains' for adding type constraints to
  1261 parameters.
  1262 
  1263 * Context expressions: renaming of parameters with syntax
  1264 redeclaration.
  1265 
  1266 * Locale declaration: 'includes' disallowed.
  1267 
  1268 * Proper static binding of attribute syntax -- i.e. types / terms /
  1269 facts mentioned as arguments are always those of the locale definition
  1270 context, independently of the context of later invocations.  Moreover,
  1271 locale operations (renaming and type / term instantiation) are applied
  1272 to attribute arguments as expected.
  1273 
  1274 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  1275 actual attributes; rare situations may require Attrib.attribute to
  1276 embed those attributes into Attrib.src that lack concrete syntax.
  1277 Attribute implementations need to cooperate properly with the static
  1278 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  1279 Attrib.XXX_thm etc. already do the right thing without further
  1280 intervention.  Only unusual applications -- such as "where" or "of"
  1281 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  1282 on the context and the facts involved -- may have to assign parsed
  1283 values to argument tokens explicitly.
  1284 
  1285 * Changed parameter management in theorem generation for long goal
  1286 statements with 'includes'.  INCOMPATIBILITY: produces a different
  1287 theorem statement in rare situations.
  1288 
  1289 * Locale inspection command 'print_locale' omits notes elements.  Use
  1290 'print_locale!' to have them included in the output.
  1291 
  1292 
  1293 *** Provers ***
  1294 
  1295 * Provers/hypsubst.ML: improved version of the subst method, for
  1296 single-step rewriting: it now works in bound variable contexts. New is
  1297 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  1298 rewrite a different subterm than the original subst method, which is
  1299 still available as 'simplesubst'.
  1300 
  1301 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  1302 and quasi orders.
  1303 
  1304 * Provers/trancl.ML: new transitivity reasoner for transitive and
  1305 reflexive-transitive closure of relations.
  1306 
  1307 * Provers/blast.ML: new reference depth_limit to make blast's depth
  1308 limit (previously hard-coded with a value of 20) user-definable.
  1309 
  1310 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  1311 is peformed already.  Object-logics merely need to finish their
  1312 initial simpset configuration as before.  INCOMPATIBILITY.
  1313 
  1314 
  1315 *** HOL ***
  1316 
  1317 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  1318 
  1319   syntax (epsilon)
  1320     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  1321 
  1322 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  1323 and x-symbol; use option '-m epsilon' to get it actually printed.
  1324 Moreover, the mathematically important symbolic identifier \<epsilon>
  1325 becomes available as variable, constant etc.  INCOMPATIBILITY,
  1326 
  1327 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  1328 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  1329 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  1330 support corresponding Isar calculations.
  1331 
  1332 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  1333 instead of ":".
  1334 
  1335 * theory SetInterval: changed the syntax for open intervals:
  1336 
  1337   Old       New
  1338   {..n(}    {..<n}
  1339   {)n..}    {n<..}
  1340   {m..n(}   {m..<n}
  1341   {)m..n}   {m<..n}
  1342   {)m..n(}  {m<..<n}
  1343 
  1344 The old syntax is still supported but will disappear in the next
  1345 release.  For conversion use the following Emacs search and replace
  1346 patterns (these are not perfect but work quite well):
  1347 
  1348   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  1349   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  1350 
  1351 * Theory Commutative_Ring (in Library): method comm_ring for proving
  1352 equalities in commutative rings; method 'algebra' provides a generic
  1353 interface.
  1354 
  1355 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  1356 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  1357 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  1358 be a tuple pattern.
  1359 
  1360 Some new syntax forms are available:
  1361 
  1362   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  1363   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  1364   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  1365   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  1366 
  1367 The latter form "\<Sum>x < k. e" used to be based on a separate
  1368 function "Summation", which has been discontinued.
  1369 
  1370 * theory Finite_Set: in structured induction proofs, the insert case
  1371 is now 'case (insert x F)' instead of the old counterintuitive 'case
  1372 (insert F x)'.
  1373 
  1374 * The 'refute' command has been extended to support a much larger
  1375 fragment of HOL, including axiomatic type classes, constdefs and
  1376 typedefs, inductive datatypes and recursion.
  1377 
  1378 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  1379 Requires zChaff with proof generation to be installed.  See
  1380 HOL/ex/SAT_Examples.thy for examples.
  1381 
  1382 * Datatype induction via method 'induct' now preserves the name of the
  1383 induction variable. For example, when proving P(xs::'a list) by
  1384 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  1385 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  1386 in unstructured proof scripts.
  1387 
  1388 * Reworked implementation of records.  Improved scalability for
  1389 records with many fields, avoiding performance problems for type
  1390 inference. Records are no longer composed of nested field types, but
  1391 of nested extension types. Therefore the record type only grows linear
  1392 in the number of extensions and not in the number of fields.  The
  1393 top-level (users) view on records is preserved.  Potential
  1394 INCOMPATIBILITY only in strange cases, where the theory depends on the
  1395 old record representation. The type generated for a record is called
  1396 <record_name>_ext_type.
  1397 
  1398 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  1399 proofs triggered by a record definition or a simproc (if
  1400 quick_and_dirty is enabled).  Definitions of large records can take
  1401 quite long.
  1402 
  1403 New simproc record_upd_simproc for simplification of multiple record
  1404 updates enabled by default.  Moreover, trivial updates are also
  1405 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  1406 occasionally, since simplification is more powerful by default.
  1407 
  1408 * typedef: proper support for polymorphic sets, which contain extra
  1409 type-variables in the term.
  1410 
  1411 * Simplifier: automatically reasons about transitivity chains
  1412 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  1413 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  1414 old proofs break occasionally as simplification may now solve more
  1415 goals than previously.
  1416 
  1417 * Simplifier: converts x <= y into x = y if assumption y <= x is
  1418 present.  Works for all partial orders (class "order"), in particular
  1419 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  1420 just like y <= x.
  1421 
  1422 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  1423 bound variable or a constant then the let is unfolded.  Otherwise
  1424 first a is simplified to b, and then f b is simplified to g. If
  1425 possible we abstract b from g arriving at "let x = b in h x",
  1426 otherwise we unfold the let and arrive at g.  The simproc can be
  1427 enabled/disabled by the reference use_let_simproc.  Potential
  1428 INCOMPATIBILITY since simplification is more powerful by default.
  1429 
  1430 * Classical reasoning: the meson method now accepts theorems as arguments.
  1431 
  1432 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  1433 jobs to provide advice on the provability of subgoals.
  1434 
  1435 * Theory OrderedGroup and Ring_and_Field: various additions and
  1436 improvements to faciliate calculations involving equalities and
  1437 inequalities.
  1438 
  1439 The following theorems have been eliminated or modified
  1440 (INCOMPATIBILITY):
  1441 
  1442   abs_eq             now named abs_of_nonneg
  1443   abs_of_ge_0        now named abs_of_nonneg
  1444   abs_minus_eq       now named abs_of_nonpos
  1445   imp_abs_id         now named abs_of_nonneg
  1446   imp_abs_neg_id     now named abs_of_nonpos
  1447   mult_pos           now named mult_pos_pos
  1448   mult_pos_le        now named mult_nonneg_nonneg
  1449   mult_pos_neg_le    now named mult_nonneg_nonpos
  1450   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  1451   mult_neg           now named mult_neg_neg
  1452   mult_neg_le        now named mult_nonpos_nonpos
  1453 
  1454 * Theory Parity: added rules for simplifying exponents.
  1455 
  1456 * Theory List:
  1457 
  1458 The following theorems have been eliminated or modified
  1459 (INCOMPATIBILITY):
  1460 
  1461   list_all_Nil       now named list_all.simps(1)
  1462   list_all_Cons      now named list_all.simps(2)
  1463   list_all_conv      now named list_all_iff
  1464   set_mem_eq         now named mem_iff
  1465 
  1466 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  1467 asymptotic "big O" calculations.  See the notes in BigO.thy.
  1468 
  1469 
  1470 *** HOL-Complex ***
  1471 
  1472 * Theory RealDef: better support for embedding natural numbers and
  1473 integers in the reals.
  1474 
  1475 The following theorems have been eliminated or modified
  1476 (INCOMPATIBILITY):
  1477 
  1478   exp_ge_add_one_self  now requires no hypotheses
  1479   real_of_int_add      reversed direction of equality (use [symmetric])
  1480   real_of_int_minus    reversed direction of equality (use [symmetric])
  1481   real_of_int_diff     reversed direction of equality (use [symmetric])
  1482   real_of_int_mult     reversed direction of equality (use [symmetric])
  1483 
  1484 * Theory RComplete: expanded support for floor and ceiling functions.
  1485 
  1486 * Theory Ln is new, with properties of the natural logarithm
  1487 
  1488 * Hyperreal: There is a new type constructor "star" for making
  1489 nonstandard types.  The old type names are now type synonyms:
  1490 
  1491   hypreal = real star
  1492   hypnat = nat star
  1493   hcomplex = complex star
  1494 
  1495 * Hyperreal: Many groups of similarly-defined constants have been
  1496 replaced by polymorphic versions (INCOMPATIBILITY):
  1497 
  1498   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  1499 
  1500   starset      <-- starsetNat, starsetC
  1501   *s*          <-- *sNat*, *sc*
  1502   starset_n    <-- starsetNat_n, starsetC_n
  1503   *sn*         <-- *sNatn*, *scn*
  1504   InternalSets <-- InternalNatSets, InternalCSets
  1505 
  1506   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  1507   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  1508   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  1509   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  1510   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  1511 
  1512 * Hyperreal: Many type-specific theorems have been removed in favor of
  1513 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  1514 
  1515   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  1516   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  1517   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  1518   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  1519   right_minus <-- hypreal_add_minus
  1520   left_minus <-- {hypreal,hcomplex}_add_minus_left
  1521   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  1522   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  1523   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  1524   mult_1_right <-- hcomplex_mult_one_right
  1525   mult_zero_left <-- hcomplex_mult_zero_left
  1526   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  1527   right_distrib <-- hypnat_add_mult_distrib2
  1528   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  1529   right_inverse <-- hypreal_mult_inverse
  1530   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  1531   order_refl <-- {hypreal,hypnat}_le_refl
  1532   order_trans <-- {hypreal,hypnat}_le_trans
  1533   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  1534   order_less_le <-- {hypreal,hypnat}_less_le
  1535   linorder_linear <-- {hypreal,hypnat}_le_linear
  1536   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  1537   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  1538   add_nonneg_nonneg <-- hypreal_le_add_order
  1539 
  1540 * Hyperreal: Separate theorems having to do with type-specific
  1541 versions of constants have been merged into theorems that apply to the
  1542 new polymorphic constants (INCOMPATIBILITY):
  1543 
  1544   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  1545   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  1546   STAR_Un <-- {STAR,NatStar,STARC}_Un
  1547   STAR_Int <-- {STAR,NatStar,STARC}_Int
  1548   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  1549   STAR_subset <-- {STAR,NatStar,STARC}_subset
  1550   STAR_mem <-- {STAR,NatStar,STARC}_mem
  1551   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  1552   STAR_diff <-- {STAR,STARC}_diff
  1553   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  1554     STARC_hcomplex_of_complex}_image_subset
  1555   starset_n_Un <-- starset{Nat,C}_n_Un
  1556   starset_n_Int <-- starset{Nat,C}_n_Int
  1557   starset_n_Compl <-- starset{Nat,C}_n_Compl
  1558   starset_n_diff <-- starset{Nat,C}_n_diff
  1559   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  1560   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  1561   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  1562   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  1563   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  1564   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  1565   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  1566   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  1567   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  1568   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  1569   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  1570   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  1571   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  1572   starfun_diff <-- starfun{C,RC,CR}_diff
  1573   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  1574   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  1575   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  1576   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  1577   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  1578   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  1579   starfun_Id <-- starfunC_Id
  1580   starfun_approx <-- starfun{Nat,CR}_approx
  1581   starfun_capprox <-- starfun{C,RC}_capprox
  1582   starfun_abs <-- starfunNat_rabs
  1583   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  1584   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  1585   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  1586   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  1587   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  1588   starfun_add_approx <-- starfunCR_add_approx
  1589   starfun_inverse_inverse <-- starfunC_inverse_inverse
  1590   starfun_divide <-- starfun{C,CR,RC}_divide
  1591   starfun_n <-- starfun{Nat,C}_n
  1592   starfun_n_mult <-- starfun{Nat,C}_n_mult
  1593   starfun_n_add <-- starfun{Nat,C}_n_add
  1594   starfun_n_add_minus <-- starfunNat_n_add_minus
  1595   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  1596   starfun_n_minus <-- starfun{Nat,C}_n_minus
  1597   starfun_n_eq <-- starfun{Nat,C}_n_eq
  1598 
  1599   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  1600   star_n_minus <-- {hypreal,hcomplex}_minus
  1601   star_n_diff <-- {hypreal,hcomplex}_diff
  1602   star_n_mult <-- {hypreal,hcomplex}_mult
  1603   star_n_inverse <-- {hypreal,hcomplex}_inverse
  1604   star_n_le <-- {hypreal,hypnat}_le
  1605   star_n_less <-- {hypreal,hypnat}_less
  1606   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  1607   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  1608   star_n_abs <-- hypreal_hrabs
  1609   star_n_divide <-- hcomplex_divide
  1610 
  1611   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  1612   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  1613   star_of_diff <-- hypreal_of_real_diff
  1614   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  1615   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  1616   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  1617   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  1618   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  1619   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  1620   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  1621   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  1622   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  1623   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  1624   star_of_number_of <-- {hypreal,hcomplex}_number_of
  1625   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  1626   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  1627   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  1628   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  1629   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  1630   star_of_power <-- hypreal_of_real_power
  1631   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  1632 
  1633 * Hyperreal: new method "transfer" that implements the transfer
  1634 principle of nonstandard analysis. With a subgoal that mentions
  1635 nonstandard types like "'a star", the command "apply transfer"
  1636 replaces it with an equivalent one that mentions only standard types.
  1637 To be successful, all free variables must have standard types; non-
  1638 standard variables must have explicit universal quantifiers.
  1639 
  1640 * Hyperreal: A theory of Taylor series.
  1641 
  1642 
  1643 *** HOLCF ***
  1644 
  1645 * Discontinued special version of 'constdefs' (which used to support
  1646 continuous functions) in favor of the general Pure one with full
  1647 type-inference.
  1648 
  1649 * New simplification procedure for solving continuity conditions; it
  1650 is much faster on terms with many nested lambda abstractions (cubic
  1651 instead of exponential time).
  1652 
  1653 * New syntax for domain package: selector names are now optional.
  1654 Parentheses should be omitted unless argument is lazy, for example:
  1655 
  1656   domain 'a stream = cons "'a" (lazy "'a stream")
  1657 
  1658 * New command 'fixrec' for defining recursive functions with pattern
  1659 matching; defining multiple functions with mutual recursion is also
  1660 supported.  Patterns may include the constants cpair, spair, up, sinl,
  1661 sinr, or any data constructor defined by the domain package. The given
  1662 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  1663 syntax and examples.
  1664 
  1665 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  1666 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  1667 but the proof obligation additionally includes an admissibility
  1668 requirement. The packages generate instances of class cpo or pcpo,
  1669 with continuity and strictness theorems for Rep and Abs.
  1670 
  1671 * HOLCF: Many theorems have been renamed according to a more standard naming
  1672 scheme (INCOMPATIBILITY):
  1673 
  1674   foo_inject:  "foo$x = foo$y ==> x = y"
  1675   foo_eq:      "(foo$x = foo$y) = (x = y)"
  1676   foo_less:    "(foo$x << foo$y) = (x << y)"
  1677   foo_strict:  "foo$UU = UU"
  1678   foo_defined: "... ==> foo$x ~= UU"
  1679   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  1680 
  1681 
  1682 *** ZF ***
  1683 
  1684 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  1685 including the First Isomorphism Theorem (on quotienting by the kernel
  1686 of a homomorphism).
  1687 
  1688 * ZF/Simplifier: install second copy of type solver that actually
  1689 makes use of TC rules declared to Isar proof contexts (or locales);
  1690 the old version is still required for ML proof scripts.
  1691 
  1692 
  1693 *** Cube ***
  1694 
  1695 * Converted to Isar theory format; use locales instead of axiomatic
  1696 theories.
  1697 
  1698 
  1699 *** ML ***
  1700 
  1701 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  1702 for ||>, ||>>, |>>,
  1703 
  1704 * Pure/library.ML no longer defines its own option datatype, but uses
  1705 that of the SML basis, which has constructors NONE and SOME instead of
  1706 None and Some, as well as exception Option.Option instead of OPTION.
  1707 The functions the, if_none, is_some, is_none have been adapted
  1708 accordingly, while Option.map replaces apsome.
  1709 
  1710 * Pure/library.ML: the exception LIST has been given up in favour of
  1711 the standard exceptions Empty and Subscript, as well as
  1712 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  1713 superceded by the standard hd and tl functions etc.
  1714 
  1715 A number of basic list functions are no longer exported to the ML
  1716 toplevel, as they are variants of predefined functions.  The following
  1717 suggests how one can translate existing code:
  1718 
  1719     rev_append xs ys = List.revAppend (xs, ys)
  1720     nth_elem (i, xs) = List.nth (xs, i)
  1721     last_elem xs = List.last xs
  1722     flat xss = List.concat xss
  1723     seq fs = List.app fs
  1724     partition P xs = List.partition P xs
  1725     mapfilter f xs = List.mapPartial f xs
  1726 
  1727 * Pure/library.ML: several combinators for linear functional
  1728 transformations, notably reverse application and composition:
  1729 
  1730   x |> f                f #> g
  1731   (x, y) |-> f          f #-> g
  1732 
  1733 * Pure/library.ML: introduced/changed precedence of infix operators:
  1734 
  1735   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  1736   infix 2 ?;
  1737   infix 3 o oo ooo oooo;
  1738   infix 4 ~~ upto downto;
  1739 
  1740 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  1741 infix operators.
  1742 
  1743 * Pure/library.ML: natural list combinators fold, fold_rev, and
  1744 fold_map support linear functional transformations and nesting.  For
  1745 example:
  1746 
  1747   fold f [x1, ..., xN] y =
  1748     y |> f x1 |> ... |> f xN
  1749 
  1750   (fold o fold) f [xs1, ..., xsN] y =
  1751     y |> fold f xs1 |> ... |> fold f xsN
  1752 
  1753   fold f [x1, ..., xN] =
  1754     f x1 #> ... #> f xN
  1755 
  1756   (fold o fold) f [xs1, ..., xsN] =
  1757     fold f xs1 #> ... #> fold f xsN
  1758 
  1759 * Pure/library.ML: the following selectors on type 'a option are
  1760 available:
  1761 
  1762   the:               'a option -> 'a  (*partial*)
  1763   these:             'a option -> 'a  where 'a = 'b list
  1764   the_default: 'a -> 'a option -> 'a
  1765   the_list:          'a option -> 'a list
  1766 
  1767 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  1768 basic operations for association lists, following natural argument
  1769 order; moreover the explicit equality predicate passed here avoids
  1770 potentially expensive polymorphic runtime equality checks.
  1771 The old functions may be expressed as follows:
  1772 
  1773   assoc = uncurry (AList.lookup (op =))
  1774   assocs = these oo AList.lookup (op =)
  1775   overwrite = uncurry (AList.update (op =)) o swap
  1776 
  1777 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  1778 
  1779   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  1780   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  1781 
  1782 replacing make_keylist and keyfilter (occassionally used)
  1783 Naive rewrites:
  1784 
  1785   make_keylist = AList.make
  1786   keyfilter = AList.find (op =)
  1787 
  1788 * eq_fst and eq_snd now take explicit equality parameter, thus
  1789   avoiding eqtypes. Naive rewrites:
  1790 
  1791     eq_fst = eq_fst (op =)
  1792     eq_snd = eq_snd (op =)
  1793 
  1794 * Removed deprecated apl and apr (rarely used).
  1795   Naive rewrites:
  1796 
  1797     apl (n, op) =>>= curry op n
  1798     apr (op, m) =>>= fn n => op (n, m)
  1799 
  1800 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  1801 provides a reasonably efficient light-weight implementation of sets as
  1802 lists.
  1803 
  1804 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  1805 few new operations; existing lookup and update are now curried to
  1806 follow natural argument order (for use with fold etc.);
  1807 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  1808 
  1809 * Pure/General: output via the Isabelle channels of
  1810 writeln/warning/error etc. is now passed through Output.output, with a
  1811 hook for arbitrary transformations depending on the print_mode
  1812 (cf. Output.add_mode -- the first active mode that provides a output
  1813 function wins).  Already formatted output may be embedded into further
  1814 text via Output.raw; the result of Pretty.string_of/str_of and derived
  1815 functions (string_of_term/cterm/thm etc.) is already marked raw to
  1816 accommodate easy composition of diagnostic messages etc.  Programmers
  1817 rarely need to care about Output.output or Output.raw at all, with
  1818 some notable exceptions: Output.output is required when bypassing the
  1819 standard channels (writeln etc.), or in token translations to produce
  1820 properly formatted results; Output.raw is required when capturing
  1821 already output material that will eventually be presented to the user
  1822 a second time.  For the default print mode, both Output.output and
  1823 Output.raw have no effect.
  1824 
  1825 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  1826 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  1827 cumulative results are displayed at the end of a batch session.
  1828 
  1829 * Pure/General: File.sysify_path and File.quote_sysify path have been
  1830 replaced by File.platform_path and File.shell_path (with appropriate
  1831 hooks).  This provides a clean interface for unusual systems where the
  1832 internal and external process view of file names are different.
  1833 
  1834 * Pure: more efficient orders for basic syntactic entities: added
  1835 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  1836 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  1837 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  1838 orders now -- potential INCOMPATIBILITY for code that depends on a
  1839 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  1840 Library.sort_strings on result).
  1841 
  1842 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  1843 fold_types traverse types/terms from left to right, observing natural
  1844 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  1845 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  1846 
  1847 * Pure: name spaces have been refined, with significant changes of the
  1848 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  1849 to extern(_table).  The plain name entry path is superceded by a
  1850 general 'naming' context, which also includes the 'policy' to produce
  1851 a fully qualified name and external accesses of a fully qualified
  1852 name; NameSpace.extend is superceded by context dependent
  1853 Sign.declare_name.  Several theory and proof context operations modify
  1854 the naming context.  Especially note Theory.restore_naming and
  1855 ProofContext.restore_naming to get back to a sane state; note that
  1856 Theory.add_path is no longer sufficient to recover from
  1857 Theory.absolute_path in particular.
  1858 
  1859 * Pure: new flags short_names (default false) and unique_names
  1860 (default true) for controlling output of qualified names.  If
  1861 short_names is set, names are printed unqualified.  If unique_names is
  1862 reset, the name prefix is reduced to the minimum required to achieve
  1863 the original result when interning again, even if there is an overlap
  1864 with earlier declarations.
  1865 
  1866 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  1867 now 'extend', and 'merge' gets an additional Pretty.pp argument
  1868 (useful for printing error messages).  INCOMPATIBILITY.
  1869 
  1870 * Pure: major reorganization of the theory context.  Type Sign.sg and
  1871 Theory.theory are now identified, referring to the universal
  1872 Context.theory (see Pure/context.ML).  Actual signature and theory
  1873 content is managed as theory data.  The old code and interfaces were
  1874 spread over many files and structures; the new arrangement introduces
  1875 considerable INCOMPATIBILITY to gain more clarity:
  1876 
  1877   Context -- theory management operations (name, identity, inclusion,
  1878     parents, ancestors, merge, etc.), plus generic theory data;
  1879 
  1880   Sign -- logical signature and syntax operations (declaring consts,
  1881     types, etc.), plus certify/read for common entities;
  1882 
  1883   Theory -- logical theory operations (stating axioms, definitions,
  1884     oracles), plus a copy of logical signature operations (consts,
  1885     types, etc.); also a few basic management operations (Theory.copy,
  1886     Theory.merge, etc.)
  1887 
  1888 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  1889 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  1890 for convenience -- they merely return the theory.
  1891 
  1892 * Pure: type Type.tsig is superceded by theory in most interfaces.
  1893 
  1894 * Pure: the Isar proof context type is already defined early in Pure
  1895 as Context.proof (note that ProofContext.context and Proof.context are
  1896 aliases, where the latter is the preferred name).  This enables other
  1897 Isabelle components to refer to that type even before Isar is present.
  1898 
  1899 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  1900 typeK, constK, axiomK, oracleK), but provide explicit operations for
  1901 any of these kinds.  For example, Sign.intern typeK is now
  1902 Sign.intern_type, Theory.hide_space Sign.typeK is now
  1903 Theory.hide_types.  Also note that former
  1904 Theory.hide_classes/types/consts are now
  1905 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  1906 internalize their arguments!  INCOMPATIBILITY.
  1907 
  1908 * Pure: get_thm interface (of PureThy and ProofContext) expects
  1909 datatype thmref (with constructors Name and NameSelection) instead of
  1910 plain string -- INCOMPATIBILITY;
  1911 
  1912 * Pure: cases produced by proof methods specify options, where NONE
  1913 means to remove case bindings -- INCOMPATIBILITY in
  1914 (RAW_)METHOD_CASES.
  1915 
  1916 * Pure: the following operations retrieve axioms or theorems from a
  1917 theory node or theory hierarchy, respectively:
  1918 
  1919   Theory.axioms_of: theory -> (string * term) list
  1920   Theory.all_axioms_of: theory -> (string * term) list
  1921   PureThy.thms_of: theory -> (string * thm) list
  1922   PureThy.all_thms_of: theory -> (string * thm) list
  1923 
  1924 * Pure: print_tac now outputs the goal through the trace channel.
  1925 
  1926 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  1927 Reference Toplevel.debug (default false) controls detailed printing
  1928 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  1929 controls execution profiling -- set to 1 for time and 2 for space
  1930 (both increase the runtime).
  1931 
  1932 * Isar session: The initial use of ROOT.ML is now always timed,
  1933 i.e. the log will show the actual process times, in contrast to the
  1934 elapsed wall-clock time that the outer shell wrapper produces.
  1935 
  1936 * Simplifier: improved handling of bound variables (nameless
  1937 representation, avoid allocating new strings).  Simprocs that invoke
  1938 the Simplifier recursively should use Simplifier.inherit_bounds to
  1939 avoid local name clashes.  Failure to do so produces warnings
  1940 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  1941 for further details.
  1942 
  1943 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  1944 bindings for all theorems stored within a given theory; this may help
  1945 in porting non-Isar theories to Isar ones, while keeping ML proof
  1946 scripts for the time being.
  1947 
  1948 * ML operator HTML.with_charset specifies the charset begin used for
  1949 generated HTML files.  For example:
  1950 
  1951   HTML.with_charset "utf-8" use_thy "Hebrew";
  1952   HTML.with_charset "utf-8" use_thy "Chinese";
  1953 
  1954 
  1955 *** System ***
  1956 
  1957 * Allow symlinks to all proper Isabelle executables (Isabelle,
  1958 isabelle, isatool etc.).
  1959 
  1960 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  1961 isatool doc, isatool mkdir, display_drafts etc.).
  1962 
  1963 * isatool usedir: option -f allows specification of the ML file to be
  1964 used by Isabelle; default is ROOT.ML.
  1965 
  1966 * New isatool version outputs the version identifier of the Isabelle
  1967 distribution being used.
  1968 
  1969 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  1970 (containing Boolean satisfiability problems) into Isabelle/HOL
  1971 theories.
  1972 
  1973 
  1974 
  1975 New in Isabelle2004 (April 2004)
  1976 --------------------------------
  1977 
  1978 *** General ***
  1979 
  1980 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  1981   Replaces linorder.ML.
  1982 
  1983 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  1984   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  1985   (\<a>...\<z>), are now considered normal letters, and can therefore
  1986   be used anywhere where an ASCII letter (a...zA...Z) has until
  1987   now. COMPATIBILITY: This obviously changes the parsing of some
  1988   terms, especially where a symbol has been used as a binder, say
  1989   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  1990   as an identifier.  Fix it by inserting a space around former
  1991   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  1992   existing theory and ML files.
  1993 
  1994 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  1995 
  1996 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  1997   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  1998   a normal (but invisible) letter. For multiple letter subscripts repeat
  1999   \<^isub> like this: x\<^isub>1\<^isub>2.
  2000 
  2001 * Pure: There are now sub-/superscripts that can span more than one
  2002   character. Text between \<^bsub> and \<^esub> is set in subscript in
  2003   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  2004   superscript. The new control characters are not identifier parts.
  2005 
  2006 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  2007   content of "..." to the latex file instead of \isacntrl... . The "..."
  2008   may consist of any printable characters excluding the end bracket >.
  2009 
  2010 * Pure: Using new Isar command "finalconsts" (or the ML functions
  2011   Theory.add_finals or Theory.add_finals_i) it is now possible to
  2012   declare constants "final", which prevents their being given a definition
  2013   later.  It is useful for constants whose behaviour is fixed axiomatically
  2014   rather than definitionally, such as the meta-logic connectives.
  2015 
  2016 * Pure: 'instance' now handles general arities with general sorts
  2017   (i.e. intersections of classes),
  2018 
  2019 * Presentation: generated HTML now uses a CSS style sheet to make layout
  2020   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  2021   It can be changed to alter the colors/layout of generated pages.
  2022 
  2023 
  2024 *** Isar ***
  2025 
  2026 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  2027   cut_tac, subgoal_tac and thin_tac:
  2028   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  2029     locales are no longer forced to write Isar proof scripts.
  2030     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  2031     emulations.
  2032   - INCOMPATIBILITY: names of variables to be instantiated may no
  2033     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  2034     This is consistent with the instantiation attribute "where".
  2035 
  2036 * Attributes "where" and "of":
  2037   - Now take type variables of instantiated theorem into account when reading
  2038     the instantiation string.  This fixes a bug that caused instantiated
  2039     theorems to have too special types in some circumstances.
  2040   - "where" permits explicit instantiations of type variables.
  2041 
  2042 * Calculation commands "moreover" and "also" no longer interfere with
  2043   current facts ("this"), admitting arbitrary combinations with "then"
  2044   and derived forms.
  2045 
  2046 * Locales:
  2047   - Goal statements involving the context element "includes" no longer
  2048     generate theorems with internal delta predicates (those ending on
  2049     "_axioms") in the premise.
  2050     Resolve particular premise with <locale>.intro to obtain old form.
  2051   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  2052     specification and "includes" elements in goal statement.
  2053   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  2054     [intro?] and [elim?] (respectively) by default.
  2055   - Experimental command for instantiation of locales in proof contexts:
  2056         instantiate <label>[<attrs>]: <loc>
  2057     Instantiates locale <loc> and adds all its theorems to the current context
  2058     taking into account their attributes.  Label and attrs are optional
  2059     modifiers, like in theorem declarations.  If present, names of
  2060     instantiated theorems are qualified with <label>, and the attributes
  2061     <attrs> are applied after any attributes these theorems might have already.
  2062       If the locale has assumptions, a chained fact of the form
  2063     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  2064     are derived.  The command does not support old-style locales declared
  2065     with "locale (open)".
  2066       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  2067 
  2068 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  2069   (Isar) contexts.
  2070 
  2071 
  2072 *** HOL ***
  2073 
  2074 * Proof import: new image HOL4 contains the imported library from
  2075   the HOL4 system with about 2500 theorems. It is imported by
  2076   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  2077   can be used like any other Isabelle image.  See
  2078   HOL/Import/HOL/README for more information.
  2079 
  2080 * Simplifier:
  2081   - Much improved handling of linear and partial orders.
  2082     Reasoners for linear and partial orders are set up for type classes
  2083     "linorder" and "order" respectively, and are added to the default simpset
  2084     as solvers.  This means that the simplifier can build transitivity chains
  2085     to solve goals from the assumptions.
  2086   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  2087     of blast or auto after simplification become unnecessary because the goal
  2088     is solved by simplification already.
  2089 
  2090 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  2091     all proved in axiomatic type classes for semirings, rings and fields.
  2092 
  2093 * Numerics:
  2094   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  2095     now formalized using the Ring_and_Field theory mentioned above.
  2096   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  2097     than before, because now they are set up once in a generic manner.
  2098   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  2099     Look for the general versions in Ring_and_Field (and Power if they concern
  2100     exponentiation).
  2101 
  2102 * Type "rat" of the rational numbers is now available in HOL-Complex.
  2103 
  2104 * Records:
  2105   - Record types are now by default printed with their type abbreviation
  2106     instead of the list of all field types. This can be configured via
  2107     the reference "print_record_type_abbr".
  2108   - Simproc "record_upd_simproc" for simplification of multiple updates added
  2109     (not enabled by default).
  2110   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  2111     EX x. x = sel r to True (not enabled by default).
  2112   - Tactic "record_split_simp_tac" to split and simplify records added.
  2113 
  2114 * 'specification' command added, allowing for definition by
  2115   specification.  There is also an 'ax_specification' command that
  2116   introduces the new constants axiomatically.
  2117 
  2118 * arith(_tac) is now able to generate counterexamples for reals as well.
  2119 
  2120 * HOL-Algebra: new locale "ring" for non-commutative rings.
  2121 
  2122 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  2123   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  2124 
  2125 * HOL-Matrix: a first theory for matrices in HOL with an application of
  2126   matrix theory to linear programming.
  2127 
  2128 * Unions and Intersections:
  2129   The latex output syntax of UN and INT has been changed
  2130   from "\Union x \in A. B" to "\Union_{x \in A} B"
  2131   i.e. the index formulae has become a subscript.
  2132   Similarly for "\Union x. B", and for \Inter instead of \Union.
  2133 
  2134 * Unions and Intersections over Intervals:
  2135   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  2136   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  2137   like in normal math, and corresponding versions for < and for intersection.
  2138 
  2139 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  2140   lexicographic dictonary ordering has been added as "lexord".
  2141 
  2142 * ML: the legacy theory structures Int and List have been removed. They had
  2143   conflicted with ML Basis Library structures having the same names.
  2144 
  2145 * 'refute' command added to search for (finite) countermodels.  Only works
  2146   for a fragment of HOL.  The installation of an external SAT solver is
  2147   highly recommended.  See "HOL/Refute.thy" for details.
  2148 
  2149 * 'quickcheck' command: Allows to find counterexamples by evaluating
  2150   formulae under an assignment of free variables to random values.
  2151   In contrast to 'refute', it can deal with inductive datatypes,
  2152   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  2153   for examples.
  2154 
  2155 
  2156 *** HOLCF ***
  2157 
  2158 * Streams now come with concatenation and are part of the HOLCF image
  2159 
  2160 
  2161 
  2162 New in Isabelle2003 (May 2003)
  2163 ------------------------------
  2164 
  2165 *** General ***
  2166 
  2167 * Provers/simplifier:
  2168 
  2169   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  2170     Assumptions are now subject to complete mutual simplification,
  2171     not just from left to right. The simplifier now preserves
  2172     the order of assumptions.
  2173 
  2174     Potential INCOMPATIBILITY:
  2175 
  2176     -- simp sometimes diverges where the old version did
  2177        not, e.g. invoking simp on the goal
  2178 
  2179         [| P (f x); y = x; f x = f y |] ==> Q
  2180 
  2181        now gives rise to the infinite reduction sequence
  2182 
  2183         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  2184 
  2185        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  2186        kind of problem.
  2187 
  2188     -- Tactics combining classical reasoner and simplification (such as auto)
  2189        are also affected by this change, because many of them rely on
  2190        simp. They may sometimes diverge as well or yield a different numbers
  2191        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  2192        in case of problems. Sometimes subsequent calls to the classical
  2193        reasoner will fail because a preceeding call to the simplifier too
  2194        eagerly simplified the goal, e.g. deleted redundant premises.
  2195 
  2196   - The simplifier trace now shows the names of the applied rewrite rules
  2197 
  2198   - You can limit the number of recursive invocations of the simplifier
  2199     during conditional rewriting (where the simplifie tries to solve the
  2200     conditions before applying the rewrite rule):
  2201     ML "simp_depth_limit := n"
  2202     where n is an integer. Thus you can force termination where previously
  2203     the simplifier would diverge.
  2204 
  2205   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  2206 
  2207   - No longer aborts on failed congruence proof.  Instead, the
  2208     congruence is ignored.
  2209 
  2210 * Pure: New generic framework for extracting programs from constructive
  2211   proofs. See HOL/Extraction.thy for an example instantiation, as well
  2212   as HOL/Extraction for some case studies.
  2213 
  2214 * Pure: The main goal of the proof state is no longer shown by default, only
  2215 the subgoals. This behaviour is controlled by a new flag.
  2216    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  2217 (ML: Proof.show_main_goal).
  2218 
  2219 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  2220 rules whose conclusion matches subgoal 1:
  2221       PG menu: Isabelle/Isar -> Show me -> matching rules
  2222 The rules are ordered by how closely they match the subgoal.
  2223 In particular, rules that solve a subgoal outright are displayed first
  2224 (or rather last, the way they are printed).
  2225 (ML: ProofGeneral.print_intros())
  2226 
  2227 * Pure: New flag trace_unify_fail causes unification to print
  2228 diagnostic information (PG: in trace buffer) when it fails. This is
  2229 useful for figuring out why single step proofs like rule, erule or
  2230 assumption failed.
  2231 
  2232 * Pure: Locale specifications now produce predicate definitions
  2233 according to the body of text (covering assumptions modulo local
  2234 definitions); predicate "loc_axioms" covers newly introduced text,
  2235 while "loc" is cumulative wrt. all included locale expressions; the
  2236 latter view is presented only on export into the global theory
  2237 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  2238 on the old view without predicates;
  2239 
  2240 * Pure: predefined locales "var" and "struct" are useful for sharing
  2241 parameters (as in CASL, for example); just specify something like
  2242 ``var x + var y + struct M'' as import;
  2243 
  2244 * Pure: improved thms_containing: proper indexing of facts instead of
  2245 raw theorems; check validity of results wrt. current name space;
  2246 include local facts of proof configuration (also covers active
  2247 locales), cover fixed variables in index; may use "_" in term
  2248 specification; an optional limit for the number of printed facts may
  2249 be given (the default is 40);
  2250 
  2251 * Pure: disallow duplicate fact bindings within new-style theory files
  2252 (batch-mode only);
  2253 
  2254 * Provers: improved induct method: assumptions introduced by case
  2255 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  2256 the goal statement); "foo" still refers to all facts collectively;
  2257 
  2258 * Provers: the function blast.overloaded has been removed: all constants
  2259 are regarded as potentially overloaded, which improves robustness in exchange
  2260 for slight decrease in efficiency;
  2261 
  2262 * Provers/linorder: New generic prover for transitivity reasoning over
  2263 linear orders.  Note: this prover is not efficient!
  2264 
  2265 * Isar: preview of problems to finish 'show' now produce an error
  2266 rather than just a warning (in interactive mode);
  2267 
  2268 
  2269 *** HOL ***
  2270 
  2271 * arith(_tac)
  2272 
  2273  - Produces a counter example if it cannot prove a goal.
  2274    Note that the counter example may be spurious if the goal is not a formula
  2275    of quantifier-free linear arithmetic.
  2276    In ProofGeneral the counter example appears in the trace buffer.
  2277 
  2278  - Knows about div k and mod k where k is a numeral of type nat or int.
  2279 
  2280  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  2281    linear arithmetic fails. This takes account of quantifiers and divisibility.
  2282    Presburger arithmetic can also be called explicitly via presburger(_tac).
  2283 
  2284 * simp's arithmetic capabilities have been enhanced a bit: it now
  2285 takes ~= in premises into account (by performing a case split);
  2286 
  2287 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  2288 are distributed over a sum of terms;
  2289 
  2290 * New tactic "trans_tac" and method "trans" instantiate
  2291 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  2292 "<=", "<" and "=").
  2293 
  2294 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  2295 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  2296 
  2297 * 'typedef' command has new option "open" to suppress the set
  2298 definition;
  2299 
  2300 * functions Min and Max on finite sets have been introduced (theory
  2301 Finite_Set);
  2302 
  2303 * attribute [symmetric] now works for relations as well; it turns
  2304 (x,y) : R^-1 into (y,x) : R, and vice versa;
  2305 
  2306 * induct over a !!-quantified statement (say !!x1..xn):
  2307   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  2308 
  2309 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  2310 %x. None. Warning: empty_def now refers to the previously hidden definition
  2311 of the empty set.
  2312 
  2313 * Algebra: formalization of classical algebra.  Intended as base for
  2314 any algebraic development in Isabelle.  Currently covers group theory
  2315 (up to Sylow's theorem) and ring theory (Universal Property of
  2316 Univariate Polynomials).  Contributions welcome;
  2317 
  2318 * GroupTheory: deleted, since its material has been moved to Algebra;
  2319 
  2320 * Complex: new directory of the complex numbers with numeric constants,
  2321 nonstandard complex numbers, and some complex analysis, standard and
  2322 nonstandard (Jacques Fleuriot);
  2323 
  2324 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  2325 
  2326 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  2327 Fleuriot);
  2328 
  2329 * Real/HahnBanach: updated and adapted to locales;
  2330 
  2331 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  2332 Gray and Kramer);
  2333 
  2334 * UNITY: added the Meier-Sanders theory of progress sets;
  2335 
  2336 * MicroJava: bytecode verifier and lightweight bytecode verifier
  2337 as abstract algorithms, instantiated to the JVM;
  2338 
  2339 * Bali: Java source language formalization. Type system, operational
  2340 semantics, axiomatic semantics. Supported language features:
  2341 classes, interfaces, objects,virtual methods, static methods,
  2342 static/instance fields, arrays, access modifiers, definite
  2343 assignment, exceptions.
  2344 
  2345 
  2346 *** ZF ***
  2347 
  2348 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  2349 universe, etc.);
  2350 
  2351 * Main ZF: virtually all theories converted to new-style format;
  2352 
  2353 
  2354 *** ML ***
  2355 
  2356 * Pure: Tactic.prove provides sane interface for internal proofs;
  2357 omits the infamous "standard" operation, so this is more appropriate
  2358 than prove_goalw_cterm in many situations (e.g. in simprocs);
  2359 
  2360 * Pure: improved error reporting of simprocs;
  2361 
  2362 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  2363 up simprocs;
  2364 
  2365 
  2366 *** Document preparation ***
  2367 
  2368 * uses \par instead of \\ for line breaks in theory text. This may
  2369 shift some page breaks in large documents. To get the old behaviour
  2370 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  2371 
  2372 * minimized dependencies of isabelle.sty and isabellesym.sty on
  2373 other packages
  2374 
  2375 * \<euro> now needs package babel/greek instead of marvosym (which
  2376 broke \Rightarrow)
  2377 
  2378 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  2379 textcomp package)
  2380 
  2381 
  2382 
  2383 New in Isabelle2002 (March 2002)
  2384 --------------------------------
  2385 
  2386 *** Document preparation ***
  2387 
  2388 * greatly simplified document preparation setup, including more
  2389 graceful interpretation of isatool usedir -i/-d/-D options, and more
  2390 instructive isatool mkdir; users should basically be able to get
  2391 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  2392 users may run a separate document processing stage manually like this:
  2393 "isatool usedir -D output HOL Test && isatool document Test/output";
  2394 
  2395 * theory dependency graph may now be incorporated into documents;
  2396 isatool usedir -g true will produce session_graph.eps/.pdf for use
  2397 with \includegraphics of LaTeX;
  2398 
  2399 * proper spacing of consecutive markup elements, especially text
  2400 blocks after section headings;
  2401 
  2402 * support bold style (for single symbols only), input syntax is like
  2403 this: "\<^bold>\<alpha>" or "\<^bold>A";
  2404 
  2405 * \<bullet> is now output as bold \cdot by default, which looks much
  2406 better in printed text;
  2407 
  2408 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  2409 note that these symbols are currently unavailable in Proof General /
  2410 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  2411 
  2412 * isatool latex no longer depends on changed TEXINPUTS, instead
  2413 isatool document copies the Isabelle style files to the target
  2414 location;
  2415 
  2416 
  2417 *** Isar ***
  2418 
  2419 * Pure/Provers: improved proof by cases and induction;
  2420   - 'case' command admits impromptu naming of parameters (such as
  2421     "case (Suc n)");
  2422   - 'induct' method divinates rule instantiation from the inductive
  2423     claim; no longer requires excessive ?P bindings for proper
  2424     instantiation of cases;
  2425   - 'induct' method properly enumerates all possibilities of set/type
  2426     rules; as a consequence facts may be also passed through *type*
  2427     rules without further ado;
  2428   - 'induct' method now derives symbolic cases from the *rulified*
  2429     rule (before it used to rulify cases stemming from the internal
  2430     atomized version); this means that the context of a non-atomic
  2431     statement becomes is included in the hypothesis, avoiding the
  2432     slightly cumbersome show "PROP ?case" form;
  2433   - 'induct' may now use elim-style induction rules without chaining
  2434     facts, using ``missing'' premises from the goal state; this allows
  2435     rules stemming from inductive sets to be applied in unstructured
  2436     scripts, while still benefitting from proper handling of non-atomic
  2437     statements; NB: major inductive premises need to be put first, all
  2438     the rest of the goal is passed through the induction;
  2439   - 'induct' proper support for mutual induction involving non-atomic
  2440     rule statements (uses the new concept of simultaneous goals, see
  2441     below);
  2442   - append all possible rule selections, but only use the first
  2443     success (no backtracking);
  2444   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  2445   - undeclared rule case names default to numbers 1, 2, 3, ...;
  2446   - added 'print_induct_rules' (covered by help item in recent Proof
  2447     General versions);
  2448   - moved induct/cases attributes to Pure, methods to Provers;
  2449   - generic method setup instantiated for FOL and HOL;
  2450 
  2451 * Pure: support multiple simultaneous goal statements, for example
  2452 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  2453 meta-level mechanism, this acts as if several individual goals had
  2454 been stated separately; in particular common proof methods need to be
  2455 repeated in order to cover all claims; note that a single elimination
  2456 step is *not* sufficient to establish the two conjunctions, so this
  2457 fails:
  2458 
  2459   assume "A & B" then have A and B ..   (*".." fails*)
  2460 
  2461 better use "obtain" in situations as above; alternative refer to
  2462 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  2463 
  2464 * Pure: proper integration with ``locales''; unlike the original
  2465 version by Florian Kammller, Isar locales package high-level proof
  2466 contexts rather than raw logical ones (e.g. we admit to include
  2467 attributes everywhere); operations on locales include merge and
  2468 rename; support for implicit arguments (``structures''); simultaneous
  2469 type-inference over imports and text; see also HOL/ex/Locales.thy for
  2470 some examples;
  2471 
  2472 * Pure: the following commands have been ``localized'', supporting a
  2473 target locale specification "(in name)": 'lemma', 'theorem',
  2474 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  2475 stored both within the locale and at the theory level (exported and
  2476 qualified by the locale name);
  2477 
  2478 * Pure: theory goals may now be specified in ``long'' form, with
  2479 ad-hoc contexts consisting of arbitrary locale elements. for example
  2480 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  2481 definitions may be given, too); the result is a meta-level rule with
  2482 the context elements being discharged in the obvious way;
  2483 
  2484 * Pure: new proof command 'using' allows to augment currently used
  2485 facts after a goal statement ('using' is syntactically analogous to
  2486 'apply', but acts on the goal's facts only); this allows chained facts
  2487 to be separated into parts given before and after a claim, as in
  2488 ``from a and b have C using d and e <proof>'';
  2489 
  2490 * Pure: renamed "antecedent" case to "rule_context";
  2491 
  2492 * Pure: new 'judgment' command records explicit information about the
  2493 object-logic embedding (used by several tools internally); no longer
  2494 use hard-wired "Trueprop";
  2495 
  2496 * Pure: added 'corollary' command;
  2497 
  2498 * Pure: fixed 'token_translation' command;
  2499 
  2500 * Pure: removed obsolete 'exported' attribute;
  2501 
  2502 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  2503 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  2504 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  2505 
  2506 * Pure: method 'atomize' presents local goal premises as object-level
  2507 statements (atomic meta-level propositions); setup controlled via
  2508 rewrite rules declarations of 'atomize' attribute; example
  2509 application: 'induct' method with proper rule statements in improper
  2510 proof *scripts*;
  2511 
  2512 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  2513 now consider the syntactic context of assumptions, giving a better
  2514 chance to get type-inference of the arguments right (this is
  2515 especially important for locales);
  2516 
  2517 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  2518 mode;
  2519 
  2520 * Pure/obtain: the formal conclusion "thesis", being marked as
  2521 ``internal'', may no longer be reference directly in the text;
  2522 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  2523 situations;
  2524 
  2525 * Pure: generic 'sym' attribute which declares a rule both as pure
  2526 'elim?' and for the 'symmetric' operation;
  2527 
  2528 * Pure: marginal comments ``--'' may now occur just anywhere in the
  2529 text; the fixed correlation with particular command syntax has been
  2530 discontinued;
  2531 
  2532 * Pure: new method 'rules' is particularly well-suited for proof
  2533 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  2534 but often produces more compact proof terms with less detours;
  2535 
  2536 * Pure/Provers/classical: simplified integration with pure rule
  2537 attributes and methods; the classical "intro?/elim?/dest?"
  2538 declarations coincide with the pure ones; the "rule" method no longer
  2539 includes classically swapped intros; "intro" and "elim" methods no
  2540 longer pick rules from the context; also got rid of ML declarations
  2541 AddXIs/AddXEs/AddXDs; all of this has some potential for
  2542 INCOMPATIBILITY;
  2543 
  2544 * Provers/classical: attribute 'swapped' produces classical inversions
  2545 of introduction rules;
  2546 
  2547 * Provers/simplifier: 'simplified' attribute may refer to explicit
  2548 rules instead of full simplifier context; 'iff' attribute handles
  2549 conditional rules;
  2550 
  2551 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  2552 
  2553 * HOL: 'recdef' now fails on unfinished automated proofs, use
  2554 "(permissive)" option to recover old behavior;
  2555 
  2556 * HOL: 'inductive' no longer features separate (collective) attributes
  2557 for 'intros' (was found too confusing);
  2558 
  2559 * HOL: properly declared induction rules less_induct and
  2560 wf_induct_rule;
  2561 
  2562 
  2563 *** HOL ***
  2564 
  2565 * HOL: moved over to sane numeral syntax; the new policy is as
  2566 follows:
  2567 
  2568   - 0 and 1 are polymorphic constants, which are defined on any
  2569   numeric type (nat, int, real etc.);
  2570 
  2571   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  2572   binary representation internally;
  2573 
  2574   - type nat has special constructor Suc, and generally prefers Suc 0
  2575   over 1::nat and Suc (Suc 0) over 2::nat;
  2576 
  2577 This change may cause significant problems of INCOMPATIBILITY; here
  2578 are some hints on converting existing sources:
  2579 
  2580   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  2581   entities, so expressions involving "-" (unary or binary minus) need
  2582   to be spaced properly;
  2583 
  2584   - existing occurrences of "1" may need to be constraint "1::nat" or
  2585   even replaced by Suc 0; similar for old "2";
  2586 
  2587   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  2588 
  2589   - remove all special provisions on numerals in proofs;
  2590 
  2591 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  2592 representation (depends on bin_arith_simps in the default context);
  2593 
  2594 * HOL: symbolic syntax for x^2 (numeral 2);
  2595 
  2596 * HOL: the class of all HOL types is now called "type" rather than
  2597 "term"; INCOMPATIBILITY, need to adapt references to this type class
  2598 in axclass/classes, instance/arities, and (usually rare) occurrences
  2599 in typings (of consts etc.); internally the class is called
  2600 "HOL.type", ML programs should refer to HOLogic.typeS;
  2601 
  2602 * HOL/record package improvements:
  2603   - new derived operations "fields" to build a partial record section,
  2604     "extend" to promote a fixed record to a record scheme, and
  2605     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  2606     declared as simp by default;
  2607   - shared operations ("more", "fields", etc.) now need to be always
  2608     qualified) --- potential INCOMPATIBILITY;
  2609   - removed "make_scheme" operations (use "make" with "extend") --
  2610     INCOMPATIBILITY;
  2611   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  2612   - provides cases/induct rules for use with corresponding Isar
  2613     methods (for concrete records, record schemes, concrete more
  2614     parts, and schematic more parts -- in that order);
  2615   - internal definitions directly based on a light-weight abstract
  2616     theory of product types over typedef rather than datatype;
  2617 
  2618 * HOL: generic code generator for generating executable ML code from
  2619 specifications; specific support for HOL constructs such as inductive
  2620 datatypes and sets, as well as recursive functions; can be invoked
  2621 via 'generate_code' theory section;
  2622 
  2623 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  2624 
  2625 * HOL: consolidated and renamed several theories.  In particular:
  2626         Ord.thy has been absorbed into HOL.thy
  2627         String.thy has been absorbed into List.thy
  2628 
  2629 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  2630 (beware of argument permutation!);
  2631 
  2632 * HOL: linorder_less_split superseded by linorder_cases;
  2633 
  2634 * HOL/List: "nodups" renamed to "distinct";
  2635 
  2636 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  2637 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  2638   - Ex_def has changed, now need to use some_eq_ex
  2639 
  2640 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  2641 in this (rare) case use:
  2642 
  2643   delSWrapper "split_all_tac"
  2644   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  2645 
  2646 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  2647 MAY FAIL;
  2648 
  2649 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  2650 Isabelle's type classes, ^ on functions and relations has too general
  2651 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  2652 necessary to attach explicit type constraints;
  2653 
  2654 * HOL/Relation: the prefix name of the infix "O" has been changed from
  2655 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  2656 renamed accordingly (eg "compI" -> "rel_compI").
  2657 
  2658 * HOL: syntax translations now work properly with numerals and records
  2659 expressions;
  2660 
  2661 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  2662 of "lam" -- INCOMPATIBILITY;
  2663 
  2664 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  2665 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  2666 renamed "Product_Type.unit";
  2667 
  2668 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  2669 
  2670 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  2671 the "cases" method);
  2672 
  2673 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  2674 Florian Kammller);
  2675 
  2676 * HOL/IMP: updated and converted to new-style theory format; several
  2677 parts turned into readable document, with proper Isar proof texts and
  2678 some explanations (by Gerwin Klein);
  2679 
  2680 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  2681 
  2682 * HOL-Hyperreal is now a logic image;
  2683 
  2684 
  2685 *** HOLCF ***
  2686 
  2687 * Isar: consts/constdefs supports mixfix syntax for continuous
  2688 operations;
  2689 
  2690 * Isar: domain package adapted to new-style theory format, e.g. see
  2691 HOLCF/ex/Dnat.thy;
  2692 
  2693 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  2694 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  2695 lift.induct_tac, always use UU instead of Undef;
  2696 
  2697 * HOLCF/IMP: updated and converted to new-style theory;
  2698 
  2699 
  2700 *** ZF ***
  2701 
  2702 * Isar: proper integration of logic-specific tools and packages,
  2703 including theory commands '(co)inductive', '(co)datatype',
  2704 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  2705 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  2706 
  2707 * theory Main no longer includes AC; for the Axiom of Choice, base
  2708 your theory on Main_ZFC;
  2709 
  2710 * the integer library now covers quotients and remainders, with many
  2711 laws relating division to addition, multiplication, etc.;
  2712 
  2713 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  2714 typeless version of the formalism;
  2715 
  2716 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  2717 format;
  2718 
  2719 * ZF/Induct: new directory for examples of inductive definitions,
  2720 including theory Multiset for multiset orderings; converted to
  2721 new-style theory format;
  2722 
  2723 * ZF: many new theorems about lists, ordinals, etc.;
  2724 
  2725 
  2726 *** General ***
  2727 
  2728 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  2729 variable proof controls level of detail: 0 = no proofs (only oracle
  2730 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  2731 also ref manual for further ML interfaces;
  2732 
  2733 * Pure/axclass: removed obsolete ML interface
  2734 goal_subclass/goal_arity;
  2735 
  2736 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  2737 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  2738 separate tokens, so expressions involving minus need to be spaced
  2739 properly;
  2740 
  2741 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  2742 rather than "infixl" or "infixr";
  2743 
  2744 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  2745 sort constraint specifications in type inference; e.g. "x::_::foo"
  2746 ensures that the type of "x" is of sort "foo" (but not necessarily a
  2747 type variable);
  2748 
  2749 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  2750 control output of nested => (types); the default behavior is
  2751 "type_brackets";
  2752 
  2753 * Pure/syntax: builtin parse translation for "_constify" turns valued
  2754 tokens into AST constants;
  2755 
  2756 * Pure/syntax: prefer later declarations of translations and print
  2757 translation functions; potential INCOMPATIBILITY: need to reverse
  2758 multiple declarations for same syntax element constant;
  2759 
  2760 * Pure/show_hyps reset by default (in accordance to existing Isar
  2761 practice);
  2762 
  2763 * Provers/classical: renamed addaltern to addafter, addSaltern to
  2764 addSafter;
  2765 
  2766 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  2767 as well;
  2768 
  2769 * system: tested support for MacOS X; should be able to get Isabelle +
  2770 Proof General to work in a plain Terminal after installing Poly/ML
  2771 (e.g. from the Isabelle distribution area) and GNU bash alone
  2772 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  2773 support requires further installations, e.g. from
  2774 http://fink.sourceforge.net/);
  2775 
  2776 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  2777 
  2778 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  2779 of 40 MB), cf. ML_OPTIONS;
  2780 
  2781 * system: Proof General keywords specification is now part of the
  2782 Isabelle distribution (see etc/isar-keywords.el);
  2783 
  2784 * system: support for persistent Proof General sessions (refrain from
  2785 outdating all loaded theories on startup); user may create writable
  2786 logic images like this: ``isabelle -q HOL Test'';
  2787 
  2788 * system: smart selection of Isabelle process versus Isabelle
  2789 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  2790 run both "isabelle" and "Isabelle" even if file names are badly
  2791 damaged (executable inspects the case of the first letter of its own
  2792 name); added separate "isabelle-process" and "isabelle-interface";
  2793 
  2794 * system: refrain from any attempt at filtering input streams; no
  2795 longer support ``8bit'' encoding of old isabelle font, instead proper
  2796 iso-latin characters may now be used; the related isatools
  2797 "symbolinput" and "nonascii" have disappeared as well;
  2798 
  2799 * system: removed old "xterm" interface (the print modes "xterm" and
  2800 "xterm_color" are still available for direct use in a suitable
  2801 terminal);
  2802 
  2803 
  2804 
  2805 New in Isabelle99-2 (February 2001)
  2806 -----------------------------------
  2807 
  2808 *** Overview of INCOMPATIBILITIES ***
  2809 
  2810 * HOL: please note that theories in the Library and elsewhere often use the
  2811 new-style (Isar) format; to refer to their theorems in an ML script you must
  2812 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  2813 
  2814 * HOL: inductive package no longer splits induction rule aggressively,
  2815 but only as far as specified by the introductions given; the old
  2816 format may be recovered via ML function complete_split_rule or attribute
  2817 'split_rule (complete)';
  2818 
  2819 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  2820 gfp_Tarski to gfp_unfold;
  2821 
  2822 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  2823 
  2824 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  2825 relation); infix "^^" has been renamed "``"; infix "``" has been
  2826 renamed "`"; "univalent" has been renamed "single_valued";
  2827 
  2828 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  2829 operation;
  2830 
  2831 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  2832 
  2833 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  2834 
  2835 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  2836 consequence, it is no longer monotonic wrt. the local goal context
  2837 (which is now passed through the inductive cases);
  2838 
  2839 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  2840 \<gg> to \<ggreater>;
  2841 
  2842 
  2843 *** Document preparation ***
  2844 
  2845 * \isabellestyle{NAME} selects version of Isabelle output (currently
  2846 available: are "it" for near math-mode best-style output, "sl" for
  2847 slanted text style, and "tt" for plain type-writer; if no
  2848 \isabellestyle command is given, output is according to slanted
  2849 type-writer);
  2850 
  2851 * support sub/super scripts (for single symbols only), input syntax is
  2852 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  2853 
  2854 * some more standard symbols; see Appendix A of the system manual for
  2855 the complete list of symbols defined in isabellesym.sty;
  2856 
  2857 * improved isabelle style files; more abstract symbol implementation
  2858 (should now use \isamath{...} and \isatext{...} in custom symbol
  2859 definitions);
  2860 
  2861 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  2862 state; Note that presentation of goal states does not conform to
  2863 actual human-readable proof documents.  Please do not include goal
  2864 states into document output unless you really know what you are doing!
  2865 
  2866 * proper indentation of antiquoted output with proportional LaTeX
  2867 fonts;
  2868 
  2869 * no_document ML operator temporarily disables LaTeX document
  2870 generation;
  2871 
  2872 * isatool unsymbolize tunes sources for plain ASCII communication;
  2873 
  2874 
  2875 *** Isar ***
  2876 
  2877 * Pure: Isar now suffers initial goal statements to contain unbound
  2878 schematic variables (this does not conform to actual readable proof
  2879 documents, due to unpredictable outcome and non-compositional proof
  2880 checking); users who know what they are doing may use schematic goals
  2881 for Prolog-style synthesis of proven results;
  2882 
  2883 * Pure: assumption method (an implicit finishing) now handles actual
  2884 rules as well;
  2885 
  2886 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  2887 initial goal, declare "that" only as Pure intro (only for single
  2888 steps); the "that" rule assumption may now be involved in implicit
  2889 finishing, thus ".." becomes a feasible for trivial obtains;
  2890 
  2891 * Pure: default proof step now includes 'intro_classes'; thus trivial
  2892 instance proofs may be performed by "..";
  2893 
  2894 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  2895 statements as well;
  2896 
  2897 * Pure: more robust selection of calculational rules;
  2898 
  2899 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  2900 rule (as well as the assumption rule);
  2901 
  2902 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  2903 lemmas, using the graph browser tool;
  2904 
  2905 * Pure: predict failure of "show" in interactive mode;
  2906 
  2907 * Pure: 'thms_containing' now takes actual terms as arguments;
  2908 
  2909 * HOL: improved method 'induct' --- now handles non-atomic goals
  2910 (potential INCOMPATIBILITY); tuned error handling;
  2911 
  2912 * HOL: cases and induct rules now provide explicit hints about the
  2913 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  2914 any remaining facts are inserted into the goal verbatim;
  2915 
  2916 * HOL: local contexts (aka cases) may now contain term bindings as
  2917 well; the 'cases' and 'induct' methods new provide a ?case binding for
  2918 the result to be shown in each case;
  2919 
  2920 * HOL: added 'recdef_tc' command;
  2921 
  2922 * isatool convert assists in eliminating legacy ML scripts;
  2923 
  2924 
  2925 *** HOL ***
  2926 
  2927 * HOL/Library: a collection of generic theories to be used together
  2928 with main HOL; the theory loader path already includes this directory
  2929 by default; the following existing theories have been moved here:
  2930 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  2931 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  2932 
  2933 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  2934 modelling and verification task performed in Isabelle/HOL +
  2935 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  2936 
  2937 * HOL/Algebra: special summation operator SUM no longer exists, it has
  2938 been replaced by setsum; infix 'assoc' now has priority 50 (like
  2939 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  2940 'domain', this makes the theory consistent with mathematical
  2941 literature;
  2942 
  2943 * HOL basics: added overloaded operations "inverse" and "divide"
  2944 (infix "/"), syntax for generic "abs" operation, generic summation
  2945 operator \<Sum>;
  2946 
  2947 * HOL/typedef: simplified package, provide more useful rules (see also
  2948 HOL/subset.thy);
  2949 
  2950 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  2951 now expressed as a proper nested rule (old-style tactic scripts may
  2952 require atomize_strip_tac to cope with non-atomic premises);
  2953 
  2954 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  2955 to "split_conv" (old name still available for compatibility);
  2956 
  2957 * HOL: improved concrete syntax for strings (e.g. allows translation
  2958 rules with string literals);
  2959 
  2960 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  2961  and Fleuriot's mechanization of analysis, including the transcendental
  2962  functions for the reals;
  2963 
  2964 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  2965 
  2966 
  2967 *** CTT ***
  2968 
  2969 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  2970 "lam" is displayed as TWO lambda-symbols
  2971 
  2972 * CTT: theory Main now available, containing everything (that is, Bool
  2973 and Arith);
  2974 
  2975 
  2976 *** General ***
  2977 
  2978 * Pure: the Simplifier has been implemented properly as a derived rule
  2979 outside of the actual kernel (at last!); the overall performance
  2980 penalty in practical applications is about 50%, while reliability of
  2981 the Isabelle inference kernel has been greatly improved;
  2982 
  2983 * print modes "brackets" and "no_brackets" control output of nested =>
  2984 (types) and ==> (props); the default behaviour is "brackets";
  2985 
  2986 * Provers: fast_tac (and friends) now handle actual object-logic rules
  2987 as assumptions as well;
  2988 
  2989 * system: support Poly/ML 4.0;
  2990 
  2991 * system: isatool install handles KDE version 1 or 2;
  2992 
  2993 
  2994 
  2995 New in Isabelle99-1 (October 2000)
  2996 ----------------------------------
  2997 
  2998 *** Overview of INCOMPATIBILITIES ***
  2999 
  3000 * HOL: simplification of natural numbers is much changed; to partly
  3001 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  3002 issue the following ML commands:
  3003 
  3004   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  3005   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  3006 
  3007 * HOL: simplification no longer dives into case-expressions; this is
  3008 controlled by "t.weak_case_cong" for each datatype t;
  3009 
  3010 * HOL: nat_less_induct renamed to less_induct;
  3011 
  3012 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  3013 fixsome to patch .thy and .ML sources automatically;
  3014 
  3015   select_equality  -> some_equality
  3016   select_eq_Ex     -> some_eq_ex
  3017   selectI2EX       -> someI2_ex
  3018   selectI2         -> someI2
  3019   selectI          -> someI
  3020   select1_equality -> some1_equality
  3021   Eps_sym_eq       -> some_sym_eq_trivial
  3022   Eps_eq           -> some_eq_trivial
  3023 
  3024 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  3025 
  3026 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  3027 instead);
  3028 
  3029 * HOL: the recursion equations generated by 'recdef' are now called
  3030 f.simps instead of f.rules;
  3031 
  3032 * HOL: qed_spec_mp now also handles bounded ALL as well;
  3033 
  3034 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  3035 sometimes be needed;
  3036 
  3037 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  3038 
  3039 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  3040 
  3041 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  3042 product is now "<*>" instead of "Times"; the lexicographic product is
  3043 now "<*lex*>" instead of "**";
  3044 
  3045 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  3046 of main HOL, but was unused); better use HOL's datatype package;
  3047 
  3048 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  3049 the old syntax may be recovered as follows:
  3050 
  3051   syntax (symbols)
  3052     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  3053       (infixl "\\<oplus>" 100)
  3054 
  3055 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3056 
  3057 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  3058 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  3059 internally;
  3060 
  3061 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  3062 changed from A/r to A//r;
  3063 
  3064 * ZF: new treatment of arithmetic (nat & int) may break some old
  3065 proofs;
  3066 
  3067 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  3068 rulify -> rule_format, elimify -> elim_format, ...);
  3069 
  3070 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3071 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  3072 should have to change intro!! to intro? only); replaced "delrule" by
  3073 "rule del";
  3074 
  3075 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  3076 
  3077 * Provers: strengthened force_tac by using new first_best_tac;
  3078 
  3079 * LaTeX document preparation: several changes of isabelle.sty (see
  3080 lib/texinputs);
  3081 
  3082 
  3083 *** Document preparation ***
  3084 
  3085 * formal comments (text blocks etc.) in new-style theories may now
  3086 contain antiquotations of thm/prop/term/typ/text to be presented
  3087 according to latex print mode; concrete syntax is like this:
  3088 @{term[show_types] "f(x) = a + x"};
  3089 
  3090 * isatool mkdir provides easy setup of Isabelle session directories,
  3091 including proper document sources;
  3092 
  3093 * generated LaTeX sources are now deleted after successful run
  3094 (isatool document -c); may retain a copy somewhere else via -D option
  3095 of isatool usedir;
  3096 
  3097 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  3098 style files, achieving self-contained LaTeX sources and simplifying
  3099 LaTeX debugging;
  3100 
  3101 * old-style theories now produce (crude) LaTeX output as well;
  3102 
  3103 * browser info session directories are now self-contained (may be put
  3104 on WWW server seperately); improved graphs of nested sessions; removed
  3105 graph for 'all sessions';
  3106 
  3107 * several improvements in isabelle style files; \isabellestyle{it}
  3108 produces fake math mode output; \isamarkupheader is now \section by
  3109 default; see lib/texinputs/isabelle.sty etc.;
  3110 
  3111 
  3112 *** Isar ***
  3113 
  3114 * Isar/Pure: local results and corresponding term bindings are now
  3115 subject to Hindley-Milner polymorphism (similar to ML); this
  3116 accommodates incremental type-inference very nicely;
  3117 
  3118 * Isar/Pure: new derived language element 'obtain' supports
  3119 generalized existence reasoning;
  3120 
  3121 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  3122 support accumulation of results, without applying any rules yet;
  3123 useful to collect intermediate results without explicit name
  3124 references, and for use with transitivity rules with more than 2
  3125 premises;
  3126 
  3127 * Isar/Pure: scalable support for case-analysis type proofs: new
  3128 'case' language element refers to local contexts symbolically, as
  3129 produced by certain proof methods; internally, case names are attached
  3130 to theorems as "tags";
  3131 
  3132 * Isar/Pure: theory command 'hide' removes declarations from
  3133 class/type/const name spaces;
  3134 
  3135 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  3136 indicate potential overloading;
  3137 
  3138 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  3139 
  3140 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  3141 "{a,b,c}" instead of {a,b,c};
  3142 
  3143 * Isar/Pure now provides its own version of intro/elim/dest
  3144 attributes; useful for building new logics, but beware of confusion
  3145 with the version in Provers/classical;
  3146 
  3147 * Isar/Pure: the local context of (non-atomic) goals is provided via
  3148 case name 'antecedent';
  3149 
  3150 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  3151 to the current context is now done automatically);
  3152 
  3153 * Isar/Pure: theory command 'method_setup' provides a simple interface
  3154 for definining proof methods in ML;
  3155 
  3156 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3157 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  3158 most cases, one should have to change intro!! to intro? only);
  3159 replaced "delrule" by "rule del";
  3160 
  3161 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  3162 'symmetric' attribute (the latter supercedes [RS sym]);
  3163 
  3164 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  3165 method modifier); 'simp' method: 'only:' modifier removes loopers as
  3166 well (including splits);
  3167 
  3168 * Isar/Provers: Simplifier and Classical methods now support all kind
  3169 of modifiers used in the past, including 'cong', 'iff', etc.
  3170 
  3171 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  3172 of Simplifier and Classical reasoner);
  3173 
  3174 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  3175 now support named cases; major packages (inductive, datatype, primrec,
  3176 recdef) support case names and properly name parameters;
  3177 
  3178 * Isar/HOL: new transitivity rules for substitution in inequalities --
  3179 monotonicity conditions are extracted to be proven at end of
  3180 calculations;
  3181 
  3182 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  3183 method anyway;
  3184 
  3185 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  3186 split_if split_if_asm; datatype package provides theorems foo.splits =
  3187 foo.split foo.split_asm for each datatype;
  3188 
  3189 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  3190 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  3191 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  3192 use "(cases (simplified))" method in proper proof texts);
  3193 
  3194 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  3195 
  3196 * Isar: names of theorems etc. may be natural numbers as well;
  3197 
  3198 * Isar: 'pr' command: optional arguments for goals_limit and
  3199 ProofContext.prems_limit; no longer prints theory contexts, but only
  3200 proof states;
  3201 
  3202 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  3203 additional print modes to be specified; e.g. "pr(latex)" will print
  3204 proof state according to the Isabelle LaTeX style;
  3205 
  3206 * Isar: improved support for emulating tactic scripts, including proof
  3207 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  3208 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  3209 (for HOL datatypes);
  3210 
  3211 * Isar: simplified (more robust) goal selection of proof methods: 1st
  3212 goal, all goals, or explicit goal specifier (tactic emulation); thus
  3213 'proof method scripts' have to be in depth-first order;
  3214 
  3215 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  3216 
  3217 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  3218 should instead use individual commands for printing items
  3219 (print_commands, print_methods etc.);
  3220 
  3221 * Isar: added 'nothing' --- the empty list of theorems;
  3222 
  3223 
  3224 *** HOL ***
  3225 
  3226 * HOL/MicroJava: formalization of a fragment of Java, together with a
  3227 corresponding virtual machine and a specification of its bytecode
  3228 verifier and a lightweight bytecode verifier, including proofs of
  3229 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  3230 Cornelia Pusch (see also the homepage of project Bali at
  3231 http://isabelle.in.tum.de/Bali/);
  3232 
  3233 * HOL/Algebra: new theory of rings and univariate polynomials, by
  3234 Clemens Ballarin;
  3235 
  3236 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  3237 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  3238 Rasmussen;
  3239 
  3240 * HOL/Lattice: fundamental concepts of lattice theory and order
  3241 structures, including duals, properties of bounds versus algebraic
  3242 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  3243 Theorem for complete lattices etc.; may also serve as a demonstration
  3244 for abstract algebraic reasoning using axiomatic type classes, and
  3245 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  3246 
  3247 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  3248 von Oheimb;
  3249 
  3250 * HOL/IMPP: extension of IMP with local variables and mutually
  3251 recursive procedures, by David von Oheimb;
  3252 
  3253 * HOL/Lambda: converted into new-style theory and document;
  3254 
  3255 * HOL/ex/Multiquote: example of multiple nested quotations and
  3256 anti-quotations -- basically a generalized version of de-Bruijn
  3257 representation; very useful in avoiding lifting of operations;
  3258 
  3259 * HOL/record: added general record equality rule to simpset; fixed
  3260 select-update simplification procedure to handle extended records as
  3261 well; admit "r" as field name;
  3262 
  3263 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  3264 other numeric types and also as the identity of groups, rings, etc.;
  3265 
  3266 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  3267 Types nat and int belong to this axclass;
  3268 
  3269 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  3270    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  3271    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  3272   two terms #m*u and #n*u are replaced by #(m+n)*u
  3273     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  3274   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  3275     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  3276 
  3277 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  3278 powerful prover for predicate logic but knows nothing of clasets; see
  3279 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  3280 
  3281 * HOL: new version of "case_tac" subsumes both boolean case split and
  3282 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  3283 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  3284 
  3285 * HOL: simplification no longer dives into case-expressions: only the
  3286 selector expression is simplified, but not the remaining arms; to
  3287 enable full simplification of case-expressions for datatype t, you may
  3288 remove t.weak_case_cong from the simpset, either globally (Delcongs
  3289 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  3290 
  3291 * HOL/recdef: the recursion equations generated by 'recdef' for
  3292 function 'f' are now called f.simps instead of f.rules; if all
  3293 termination conditions are proved automatically, these simplification
  3294 rules are added to the simpset, as in primrec; rules may be named
  3295 individually as well, resulting in a separate list of theorems for
  3296 each equation;
  3297 
  3298 * HOL/While is a new theory that provides a while-combinator. It
  3299 permits the definition of tail-recursive functions without the
  3300 provision of a termination measure. The latter is necessary once the
  3301 invariant proof rule for while is applied.
  3302 
  3303 * HOL: new (overloaded) notation for the set of elements below/above
  3304 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  3305 
  3306 * HOL: theorems impI, allI, ballI bound as "strip";
  3307 
  3308 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  3309 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  3310 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  3311 
  3312 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3313 
  3314 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  3315 main HOL, but was unused);
  3316 
  3317 * HOL: fewer consts declared as global (e.g. have to refer to
  3318 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  3319 
  3320 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  3321 in case of overlap with user translations (e.g. judgements over
  3322 tuples); (note that the underlying logical represenation is still
  3323 bogus);
  3324 
  3325 
  3326 *** ZF ***
  3327 
  3328 * ZF: simplification automatically cancels common terms in arithmetic
  3329 expressions over nat and int;
  3330 
  3331 * ZF: new treatment of nat to minimize type-checking: all operators
  3332 coerce their operands to a natural number using the function natify,
  3333 making the algebraic laws unconditional;
  3334 
  3335 * ZF: as above, for int: operators coerce their operands to an integer
  3336 using the function intify;
  3337 
  3338 * ZF: the integer library now contains many of the usual laws for the
  3339 orderings, including $<=, and monotonicity laws for $+ and $*;
  3340 
  3341 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  3342 simplification;
  3343 
  3344 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  3345 to the simplifier and classical reasoner simultaneously;
  3346 
  3347 
  3348 *** General ***
  3349 
  3350 * Provers: blast_tac now handles actual object-logic rules as
  3351 assumptions; note that auto_tac uses blast_tac internally as well;
  3352 
  3353 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  3354 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  3355 
  3356 * Provers: delrules now handles destruct rules as well (no longer need
  3357 explicit make_elim);
  3358 
  3359 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  3360   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3361 use instead the strong form,
  3362   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3363 in HOL, FOL and ZF the function cla_make_elim will create such rules
  3364 from destruct-rules;
  3365 
  3366 * Provers: Simplifier.easy_setup provides a fast path to basic
  3367 Simplifier setup for new object-logics;
  3368 
  3369 * Pure: AST translation rules no longer require constant head on LHS;
  3370 
  3371 * Pure: improved name spaces: ambiguous output is qualified; support
  3372 for hiding of names;
  3373 
  3374 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  3375 XSYMBOL_HOME; no longer need to do manual configuration in most
  3376 situations;
  3377 
  3378 * system: compression of ML heaps images may now be controlled via -c
  3379 option of isabelle and isatool usedir (currently only observed by
  3380 Poly/ML);
  3381 
  3382 * system: isatool installfonts may handle X-Symbol fonts as well (very
  3383 useful for remote X11);
  3384 
  3385 * system: provide TAGS file for Isabelle sources;
  3386 
  3387 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  3388 order;
  3389 
  3390 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  3391 timing flag supersedes proof_timing and Toplevel.trace;
  3392 
  3393 * ML: new combinators |>> and |>>> for incremental transformations
  3394 with secondary results (e.g. certain theory extensions):
  3395 
  3396 * ML: PureThy.add_defs gets additional argument to indicate potential
  3397 overloading (usually false);
  3398 
  3399 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  3400 results;
  3401 
  3402 
  3403 
  3404 New in Isabelle99 (October 1999)
  3405 --------------------------------
  3406 
  3407 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3408 
  3409 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  3410 are no longer simplified.  (This allows the simplifier to unfold recursive
  3411 functional programs.)  To restore the old behaviour, declare
  3412 
  3413     Delcongs [if_weak_cong];
  3414 
  3415 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  3416 complement;
  3417 
  3418 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  3419 
  3420 * HOL/datatype: mutual_induct_tac no longer exists --
  3421   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  3422 
  3423 * HOL/typedef: fixed type inference for representing set; type
  3424 arguments now have to occur explicitly on the rhs as type constraints;
  3425 
  3426 * ZF: The con_defs part of an inductive definition may no longer refer
  3427 to constants declared in the same theory;
  3428 
  3429 * HOL, ZF: the function mk_cases, generated by the inductive
  3430 definition package, has lost an argument.  To simplify its result, it
  3431 uses the default simpset instead of a supplied list of theorems.
  3432 
  3433 * HOL/List: the constructors of type list are now Nil and Cons;
  3434 
  3435 * Simplifier: the type of the infix ML functions
  3436         setSSolver addSSolver setSolver addSolver
  3437 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  3438 for packaging solvers. A solver is created via
  3439         mk_solver: string -> (thm list -> int -> tactic) -> solver
  3440 where the string argument is only a comment.
  3441 
  3442 
  3443 *** Proof tools ***
  3444 
  3445 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  3446 decision procedure for linear arithmetic. Currently it is used for
  3447 types `nat', `int', and `real' in HOL (see below); it can, should and
  3448 will be instantiated for other types and logics as well.
  3449 
  3450 * The simplifier now accepts rewrite rules with flexible heads, eg
  3451      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  3452   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  3453   matching.
  3454 
  3455 
  3456 *** General ***
  3457 
  3458 * New Isabelle/Isar subsystem provides an alternative to traditional
  3459 tactical theorem proving; together with the ProofGeneral/isar user
  3460 interface it offers an interactive environment for developing human
  3461 readable proof documents (Isar == Intelligible semi-automated
  3462 reasoning); for further information see isatool doc isar-ref,
  3463 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  3464 
  3465 * improved and simplified presentation of theories: better HTML markup
  3466 (including colors), graph views in several sizes; isatool usedir now
  3467 provides a proper interface for user theories (via -P option); actual
  3468 document preparation based on (PDF)LaTeX is available as well (for
  3469 new-style theories only); see isatool doc system for more information;
  3470 
  3471 * native support for Proof General, both for classic Isabelle and
  3472 Isabelle/Isar;
  3473 
  3474 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  3475 using the graph browser tool;
  3476 
  3477 * Isabelle manuals now also available as PDF;
  3478 
  3479 * theory loader rewritten from scratch (may not be fully
  3480 bug-compatible); old loadpath variable has been replaced by show_path,
  3481 add_path, del_path, reset_path functions; new operations such as
  3482 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  3483 isatool doc ref);
  3484 
  3485 * improved isatool install: option -k creates KDE application icon,
  3486 option -p DIR installs standalone binaries;
  3487 
  3488 * added ML_PLATFORM setting (useful for cross-platform installations);
  3489 more robust handling of platform specific ML images for SML/NJ;
  3490 
  3491 * the settings environment is now statically scoped, i.e. it is never
  3492 created again in sub-processes invoked from isabelle, isatool, or
  3493 Isabelle;
  3494 
  3495 * path element specification '~~' refers to '$ISABELLE_HOME';
  3496 
  3497 * in locales, the "assumes" and "defines" parts may be omitted if
  3498 empty;
  3499 
  3500 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  3501 long arrows);
  3502 
  3503 * new print_mode "HTML";
  3504 
  3505 * new flag show_tags controls display of tags of theorems (which are
  3506 basically just comments that may be attached by some tools);
  3507 
  3508 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  3509 mode and goal output format:
  3510 
  3511 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  3512 244c244
  3513 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  3514 ---
  3515 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  3516 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  3517 181c181
  3518 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  3519 ---
  3520 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  3521 
  3522 * function bind_thms stores lists of theorems (cf. bind_thm);
  3523 
  3524 * new shorthand tactics ftac, eatac, datac, fatac;
  3525 
  3526 * qed (and friends) now accept "" as result name; in that case the
  3527 theorem is not stored, but proper checks and presentation of the
  3528 result still apply;
  3529 
  3530 * theorem database now also indexes constants "Trueprop", "all",
  3531 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  3532 
  3533 
  3534 *** HOL ***
  3535 
  3536 ** HOL arithmetic **
  3537 
  3538 * There are now decision procedures for linear arithmetic over nat and
  3539 int:
  3540 
  3541 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  3542 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  3543 are treated as atomic; subformulae not involving type `nat' or `int'
  3544 are ignored; quantified subformulae are ignored unless they are
  3545 positive universal or negative existential. The tactic has to be
  3546 invoked by hand and can be a little bit slow. In particular, the
  3547 running time is exponential in the number of occurrences of `min' and
  3548 `max', and `-' on `nat'.
  3549 
  3550 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  3551 (negated) (in)equalities among the premises and the conclusion into
  3552 account (i.e. no compound formulae) and does not know about `min' and
  3553 `max', and `-' on `nat'. It is fast and is used automatically by the
  3554 simplifier.
  3555 
  3556 NB: At the moment, these decision procedures do not cope with mixed
  3557 nat/int formulae where the two parts interact, such as `m < n ==>
  3558 int(m) < int(n)'.
  3559 
  3560 * HOL/Numeral provides a generic theory of numerals (encoded
  3561 efficiently as bit strings); setup for types nat/int/real is in place;
  3562 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  3563 int, existing theories and proof scripts may require a few additional
  3564 type constraints;
  3565 
  3566 * integer division and remainder can now be performed on constant
  3567 arguments;
  3568 
  3569 * many properties of integer multiplication, division and remainder
  3570 are now available;
  3571 
  3572 * An interface to the Stanford Validity Checker (SVC) is available through the
  3573 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  3574 are proved automatically.  SVC must be installed separately, and its results
  3575 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  3576 invocation of the underlying oracle).  For SVC see
  3577   http://verify.stanford.edu/SVC
  3578 
  3579 * IsaMakefile: the HOL-Real target now builds an actual image;
  3580 
  3581 
  3582 ** HOL misc **
  3583 
  3584 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  3585 (in Isabelle/Isar) -- by Gertrud Bauer;
  3586 
  3587 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  3588 analysis for assembly languages with subtypes;
  3589 
  3590 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  3591 -- avoids syntactic ambiguities and treats state, transition, and
  3592 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  3593 changed syntax and (many) tactics;
  3594 
  3595 * HOL/inductive: Now also handles more general introduction rules such
  3596   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  3597   theorems are now maintained within the theory (maintained via the
  3598   "mono" attribute);
  3599 
  3600 * HOL/datatype: Now also handles arbitrarily branching datatypes
  3601   (using function types) such as
  3602 
  3603   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  3604 
  3605 * HOL/record: record_simproc (part of the default simpset) takes care
  3606 of selectors applied to updated records; record_split_tac is no longer
  3607 part of the default claset; update_defs may now be removed from the
  3608 simpset in many cases; COMPATIBILITY: old behavior achieved by
  3609 
  3610   claset_ref () := claset() addSWrapper record_split_wrapper;
  3611   Delsimprocs [record_simproc]
  3612 
  3613 * HOL/typedef: fixed type inference for representing set; type
  3614 arguments now have to occur explicitly on the rhs as type constraints;
  3615 
  3616 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  3617 names rather than an ML expression;
  3618 
  3619 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  3620 supplied later.  Program schemes can be defined, such as
  3621     "While B C s = (if B s then While B C (C s) else s)"
  3622 where the well-founded relation can be chosen after B and C have been given.
  3623 
  3624 * HOL/List: the constructors of type list are now Nil and Cons;
  3625 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  3626 course, ML tools referring to List.list.op # etc. have to be adapted;
  3627 
  3628 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  3629 disabled by default; run isabelle with option -m HOL to get back to
  3630 the original Gordon/HOL-style output;
  3631 
  3632 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  3633 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  3634 
  3635 * HOL basic syntax simplified (more orthogonal): all variants of
  3636 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  3637 Eps operator is provided as well: "SOME x. P[x]";
  3638 
  3639 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  3640 
  3641 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  3642 thus available for user theories;
  3643 
  3644 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  3645 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  3646 time;
  3647 
  3648 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  3649 several times and then mp;
  3650 
  3651 
  3652 *** LK ***
  3653 
  3654 * the notation <<...>> is now available as a notation for sequences of
  3655 formulas;
  3656 
  3657 * the simplifier is now installed
  3658 
  3659 * the axiom system has been generalized (thanks to Soren Heilmann)
  3660 
  3661 * the classical reasoner now has a default rule database
  3662 
  3663 
  3664 *** ZF ***
  3665 
  3666 * new primrec section allows primitive recursive functions to be given
  3667 directly (as in HOL) over datatypes and the natural numbers;
  3668 
  3669 * new tactics induct_tac and exhaust_tac for induction (or case
  3670 analysis) over datatypes and the natural numbers;
  3671 
  3672 * the datatype declaration of type T now defines the recursor T_rec;
  3673 
  3674 * simplification automatically does freeness reasoning for datatype
  3675 constructors;
  3676 
  3677 * automatic type-inference, with AddTCs command to insert new
  3678 type-checking rules;
  3679 
  3680 * datatype introduction rules are now added as Safe Introduction rules
  3681 to the claset;
  3682 
  3683 * the syntax "if P then x else y" is now available in addition to
  3684 if(P,x,y);
  3685 
  3686 
  3687 *** Internal programming interfaces ***
  3688 
  3689 * tuned simplifier trace output; new flag debug_simp;
  3690 
  3691 * structures Vartab / Termtab (instances of TableFun) offer efficient
  3692 tables indexed by indexname_ord / term_ord (compatible with aconv);
  3693 
  3694 * AxClass.axclass_tac lost the theory argument;
  3695 
  3696 * tuned current_goals_markers semantics: begin / end goal avoids
  3697 printing empty lines;
  3698 
  3699 * removed prs and prs_fn hook, which was broken because it did not
  3700 include \n in its semantics, forcing writeln to add one
  3701 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  3702 string -> unit if you really want to output text without newline;
  3703 
  3704 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  3705 plain output, interface builders may have to enable 'isabelle_font'
  3706 mode to get Isabelle font glyphs as before;
  3707 
  3708 * refined token_translation interface; INCOMPATIBILITY: output length
  3709 now of type real instead of int;
  3710 
  3711 * theory loader actions may be traced via new ThyInfo.add_hook
  3712 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  3713 your own database of information attached to *whole* theories -- as
  3714 opposed to intra-theory data slots offered via TheoryDataFun;
  3715 
  3716 * proper handling of dangling sort hypotheses (at last!);
  3717 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  3718 extra sort hypotheses that can be witnessed from the type signature;
  3719 the force_strip_shyps flag is gone, any remaining shyps are simply
  3720 left in the theorem (with a warning issued by strip_shyps_warning);
  3721 
  3722 
  3723 
  3724 New in Isabelle98-1 (October 1998)
  3725 ----------------------------------
  3726 
  3727 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3728 
  3729 * several changes of automated proof tools;
  3730 
  3731 * HOL: major changes to the inductive and datatype packages, including
  3732 some minor incompatibilities of theory syntax;
  3733 
  3734 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  3735 called `inj_on';
  3736 
  3737 * HOL: removed duplicate thms in Arith:
  3738   less_imp_add_less  should be replaced by  trans_less_add1
  3739   le_imp_add_le      should be replaced by  trans_le_add1
  3740 
  3741 * HOL: unary minus is now overloaded (new type constraints may be
  3742 required);
  3743 
  3744 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  3745 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  3746 now taken as an integer constant.
  3747 
  3748 * Pure: ML function 'theory_of' renamed to 'theory';
  3749 
  3750 
  3751 *** Proof tools ***
  3752 
  3753 * Simplifier:
  3754   1. Asm_full_simp_tac is now more aggressive.
  3755      1. It will sometimes reorient premises if that increases their power to
  3756         simplify.
  3757      2. It does no longer proceed strictly from left to right but may also
  3758         rotate premises to achieve further simplification.
  3759      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  3760      old Asm_full_simp_tac in that it does not rotate premises.
  3761   2. The simplifier now knows a little bit about nat-arithmetic.
  3762 
  3763 * Classical reasoner: wrapper mechanism for the classical reasoner now
  3764 allows for selected deletion of wrappers, by introduction of names for
  3765 wrapper functionals.  This implies that addbefore, addSbefore,
  3766 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  3767 and that adding two tactics with the same name overwrites the first
  3768 one (emitting a warning).
  3769   type wrapper = (int -> tactic) -> (int -> tactic)
  3770   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  3771   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  3772   delWrapper, delSWrapper: claset *  string            -> claset
  3773   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  3774 
  3775 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  3776 semantics; addbefore now affects only the unsafe part of step_tac
  3777 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  3778 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  3779 by Force_tac;
  3780 
  3781 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  3782 compWrapper; added safe wrapper (and access functions for it);
  3783 
  3784 * HOL/split_all_tac is now much faster and fails if there is nothing
  3785 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  3786 and the names of the automatically generated variables have changed.
  3787 split_all_tac has moved within claset() from unsafe wrappers to safe
  3788 wrappers, which means that !!-bound variables are split much more
  3789 aggressively, and safe_tac and clarify_tac now split such variables.
  3790 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  3791 Note: the same holds for record_split_tac, which does the job of
  3792 split_all_tac for record fields.
  3793 
  3794 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  3795 permanently to the default simpset using Addsplits just like
  3796 Addsimps. They can be removed via Delsplits just like
  3797 Delsimps. Lower-case versions are also available.
  3798 
  3799 * HOL/Simplifier: The rule split_if is now part of the default
  3800 simpset. This means that the simplifier will eliminate all occurrences
  3801 of if-then-else in the conclusion of a goal. To prevent this, you can
  3802 either remove split_if completely from the default simpset by
  3803 `Delsplits [split_if]' or remove it in a specific call of the
  3804 simplifier using `... delsplits [split_if]'.  You can also add/delete
  3805 other case splitting rules to/from the default simpset: every datatype
  3806 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  3807 t is the name of the datatype).
  3808 
  3809 * Classical reasoner / Simplifier combination: new force_tac (and
  3810 derivatives Force_tac, force) combines rewriting and classical
  3811 reasoning (and whatever other tools) similarly to auto_tac, but is
  3812 aimed to solve the given subgoal completely.
  3813 
  3814 
  3815 *** General ***
  3816 
  3817 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  3818 and `goalw': the theory is no longer needed as an explicit argument -
  3819 the current theory context is used; assumptions are no longer returned
  3820 at the ML-level unless one of them starts with ==> or !!; it is
  3821 recommended to convert to these new commands using isatool fixgoal
  3822 (backup your sources first!);
  3823 
  3824 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  3825 the current theory context, and 'theory' to lookup stored theories;
  3826 
  3827 * new theory section 'locale' for declaring constants, assumptions and
  3828 definitions that have local scope;
  3829 
  3830 * new theory section 'nonterminals' for purely syntactic types;
  3831 
  3832 * new theory section 'setup' for generic ML setup functions
  3833 (e.g. package initialization);
  3834 
  3835 * the distribution now includes Isabelle icons: see
  3836 lib/logo/isabelle-{small,tiny}.xpm;
  3837 
  3838 * isatool install - install binaries with absolute references to
  3839 ISABELLE_HOME/bin;
  3840 
  3841 * isatool logo -- create instances of the Isabelle logo (as EPS);
  3842 
  3843 * print mode 'emacs' reserved for Isamode;
  3844 
  3845 * support multiple print (ast) translations per constant name;
  3846 
  3847 * theorems involving oracles are now printed with a suffixed [!];
  3848 
  3849 
  3850 *** HOL ***
  3851 
  3852 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  3853 
  3854 * HOL/inductive package reorganized and improved: now supports mutual
  3855 definitions such as
  3856 
  3857   inductive EVEN ODD
  3858     intrs
  3859       null "0 : EVEN"
  3860       oddI "n : EVEN ==> Suc n : ODD"
  3861       evenI "n : ODD ==> Suc n : EVEN"
  3862 
  3863 new theorem list "elims" contains an elimination rule for each of the
  3864 recursive sets; inductive definitions now handle disjunctive premises
  3865 correctly (also ZF);
  3866 
  3867 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  3868 "mutual_induct" no longer exists - the induction rule is always
  3869 contained in "induct";
  3870 
  3871 
  3872 * HOL/datatype package re-implemented and greatly improved: now
  3873 supports mutually recursive datatypes such as
  3874 
  3875   datatype
  3876     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  3877             | SUM ('a aexp) ('a aexp)
  3878             | DIFF ('a aexp) ('a aexp)
  3879             | NUM 'a
  3880   and
  3881     'a bexp = LESS ('a aexp) ('a aexp)
  3882             | AND ('a bexp) ('a bexp)
  3883             | OR ('a bexp) ('a bexp)
  3884 
  3885 as well as indirectly recursive datatypes such as
  3886 
  3887   datatype
  3888     ('a, 'b) term = Var 'a
  3889                   | App 'b ((('a, 'b) term) list)
  3890 
  3891 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  3892 induction on mutually / indirectly recursive datatypes.
  3893 
  3894 Primrec equations are now stored in theory and can be accessed via
  3895 <function_name>.simps.
  3896 
  3897 INCOMPATIBILITIES:
  3898 
  3899   - Theories using datatypes must now have theory Datatype as an
  3900     ancestor.
  3901   - The specific <typename>.induct_tac no longer exists - use the
  3902     generic induct_tac instead.
  3903   - natE has been renamed to nat.exhaust - use exhaust_tac
  3904     instead of res_inst_tac ... natE. Note that the variable
  3905     names in nat.exhaust differ from the names in natE, this
  3906     may cause some "fragile" proofs to fail.
  3907   - The theorems split_<typename>_case and split_<typename>_case_asm
  3908     have been renamed to <typename>.split and <typename>.split_asm.
  3909   - Since default sorts of type variables are now handled correctly,
  3910     some datatype definitions may have to be annotated with explicit
  3911     sort constraints.
  3912   - Primrec definitions no longer require function name and type
  3913     of recursive argument.
  3914 
  3915 Consider using isatool fixdatatype to adapt your theories and proof
  3916 scripts to the new package (backup your sources first!).
  3917 
  3918 
  3919 * HOL/record package: considerably improved implementation; now
  3920 includes concrete syntax for record types, terms, updates; theorems
  3921 for surjective pairing and splitting !!-bound record variables; proof
  3922 support is as follows:
  3923 
  3924   1) standard conversions (selectors or updates applied to record
  3925 constructor terms) are part of the standard simpset;
  3926 
  3927   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  3928 made part of standard simpset and claset via addIffs;
  3929 
  3930   3) a tactic for record field splitting (record_split_tac) is part of
  3931 the standard claset (addSWrapper);
  3932 
  3933 To get a better idea about these rules you may retrieve them via
  3934 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  3935 the name of your record type.
  3936 
  3937 The split tactic 3) conceptually simplifies by the following rule:
  3938 
  3939   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  3940 
  3941 Thus any record variable that is bound by meta-all will automatically
  3942 blow up into some record constructor term, consequently the
  3943 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  3944 solve record problems automatically.
  3945 
  3946 
  3947 * reorganized the main HOL image: HOL/Integ and String loaded by
  3948 default; theory Main includes everything;
  3949 
  3950 * automatic simplification of integer sums and comparisons, using cancellation;
  3951 
  3952 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  3953 
  3954 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  3955 
  3956 * many new identities for unions, intersections, set difference, etc.;
  3957 
  3958 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  3959 called split_if, split_split, split_sum_case and split_nat_case (to go
  3960 with add/delsplits);
  3961 
  3962 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  3963 (?x::unit) = (); this is made part of the default simpset, which COULD
  3964 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  3965 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  3966 unit_abs_eta_conv is added in order to counter the effect of
  3967 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  3968 %u.f();
  3969 
  3970 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  3971 makes more sense);
  3972 
  3973 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  3974   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  3975   disjointness reasoning but breaking a few old proofs.
  3976 
  3977 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  3978 to 'converse' from 'inverse' (for compatibility with ZF and some
  3979 literature);
  3980 
  3981 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  3982 the well-founded relation;
  3983 
  3984 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  3985     Compl A.  The "Compl" syntax remains available as input syntax for this
  3986     release ONLY.
  3987 
  3988 * HOL/Update: new theory of function updates:
  3989     f(a:=b) == %x. if x=a then b else f x
  3990 may also be iterated as in f(a:=b,c:=d,...);
  3991 
  3992 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  3993 
  3994 * HOL/List:
  3995   - new function list_update written xs[i:=v] that updates the i-th
  3996     list position. May also be iterated as in xs[i:=a,j:=b,...].
  3997   - new function `upt' written [i..j(] which generates the list
  3998     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  3999     bound write [i..j], which is a shorthand for [i..j+1(].
  4000   - new lexicographic orderings and corresponding wellfoundedness theorems.
  4001 
  4002 * HOL/Arith:
  4003   - removed 'pred' (predecessor) function;
  4004   - generalized some theorems about n-1;
  4005   - many new laws about "div" and "mod";
  4006   - new laws about greatest common divisors (see theory ex/Primes);
  4007 
  4008 * HOL/Relation: renamed the relational operator r^-1 "converse"
  4009 instead of "inverse";
  4010 
  4011 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  4012   of the multiset ordering;
  4013 
  4014 * directory HOL/Real: a construction of the reals using Dedekind cuts
  4015   (not included by default);
  4016 
  4017 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  4018 
  4019 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  4020   programs, i.e. different program variables may have different types.
  4021 
  4022 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4023   [previously, this check worked only if the rewrite rule was unconditional]
  4024   Now rew can involve either definitions or equalities (either == or =).
  4025 
  4026 
  4027 *** ZF ***
  4028 
  4029 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  4030   only the theorems proved on ZF.ML;
  4031 
  4032 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4033   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4034   disjointness reasoning but breaking a few old proofs.
  4035 
  4036 * ZF/Update: new theory of function updates
  4037     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  4038   may also be iterated as in f(a:=b,c:=d,...);
  4039 
  4040 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  4041 
  4042 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4043   [previously, this check worked only if the rewrite rule was unconditional]
  4044   Now rew can involve either definitions or equalities (either == or =).
  4045 
  4046 * case_tac provided for compatibility with HOL
  4047     (like the old excluded_middle_tac, but with subgoals swapped)
  4048 
  4049 
  4050 *** Internal programming interfaces ***
  4051 
  4052 * Pure: several new basic modules made available for general use, see
  4053 also src/Pure/README;
  4054 
  4055 * improved the theory data mechanism to support encapsulation (data
  4056 kind name replaced by private Object.kind, acting as authorization
  4057 key); new type-safe user interface via functor TheoryDataFun; generic
  4058 print_data function becomes basically useless;
  4059 
  4060 * removed global_names compatibility flag -- all theory declarations
  4061 are qualified by default;
  4062 
  4063 * module Pure/Syntax now offers quote / antiquote translation
  4064 functions (useful for Hoare logic etc. with implicit dependencies);
  4065 see HOL/ex/Antiquote for an example use;
  4066 
  4067 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  4068 cterm -> thm;
  4069 
  4070 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  4071 subgoal;
  4072 
  4073 * Display.print_goals function moved to Locale.print_goals;
  4074 
  4075 * standard print function for goals supports current_goals_markers
  4076 variable for marking begin of proof, end of proof, start of goal; the
  4077 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  4078 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  4079 for example;
  4080 
  4081 
  4082 
  4083 New in Isabelle98 (January 1998)
  4084 --------------------------------
  4085 
  4086 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4087 
  4088 * changed lexical syntax of terms / types: dots made part of long
  4089 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  4090 
  4091 * simpset (and claset) reference variable replaced by functions
  4092 simpset / simpset_ref;
  4093 
  4094 * no longer supports theory aliases (via merge) and non-trivial
  4095 implicit merge of thms' signatures;
  4096 
  4097 * most internal names of constants changed due to qualified names;
  4098 
  4099 * changed Pure/Sequence interface (see Pure/seq.ML);
  4100 
  4101 
  4102 *** General Changes ***
  4103 
  4104 * hierachically structured name spaces (for consts, types, axms, thms
  4105 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  4106 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  4107 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  4108 long_names for fully qualified output names; NOTE: ML programs
  4109 (special tactics, packages etc.) referring to internal names may have
  4110 to be adapted to cope with fully qualified names; in case of severe
  4111 backward campatibility problems try setting 'global_names' at compile
  4112 time to have enrything declared within a flat name space; one may also
  4113 fine tune name declarations in theories via the 'global' and 'local'
  4114 section;
  4115 
  4116 * reimplemented the implicit simpset and claset using the new anytype
  4117 data filed in signatures; references simpset:simpset ref etc. are
  4118 replaced by functions simpset:unit->simpset and
  4119 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  4120 to patch your ML files accordingly;
  4121 
  4122 * HTML output now includes theory graph data for display with Java
  4123 applet or isatool browser; data generated automatically via isatool
  4124 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  4125 
  4126 * defs may now be conditional; improved rewrite_goals_tac to handle
  4127 conditional equations;
  4128 
  4129 * defs now admits additional type arguments, using TYPE('a) syntax;
  4130 
  4131 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  4132 creates a new theory node; implicit merge of thms' signatures is
  4133 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  4134 transfer:theory->thm->thm in (rare) cases;
  4135 
  4136 * improved handling of draft signatures / theories; draft thms (and
  4137 ctyps, cterms) are automatically promoted to real ones;
  4138 
  4139 * slightly changed interfaces for oracles: admit many per theory, named
  4140 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  4141 
  4142 * print_goals: optional output of const types (set show_consts and
  4143 show_types);
  4144 
  4145 * improved output of warnings (###) and errors (***);
  4146 
  4147 * subgoal_tac displays a warning if the new subgoal has type variables;
  4148 
  4149 * removed old README and Makefiles;
  4150 
  4151 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  4152 
  4153 * removed obsolete init_pps and init_database;
  4154 
  4155 * deleted the obsolete tactical STATE, which was declared by
  4156     fun STATE tacfun st = tacfun st st;
  4157 
  4158 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  4159 (which abbreviates $HOME);
  4160 
  4161 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  4162 use isatool fixseq to adapt your ML programs (this works for fully
  4163 qualified references to the Sequence structure only!);
  4164 
  4165 * use_thy no longer requires writable current directory; it always
  4166 reloads .ML *and* .thy file, if either one is out of date;
  4167 
  4168 
  4169 *** Classical Reasoner ***
  4170 
  4171 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  4172 tactics that use classical reasoning to simplify a subgoal without
  4173 splitting it into several subgoals;
  4174 
  4175 * Safe_tac: like safe_tac but uses the default claset;
  4176 
  4177 
  4178 *** Simplifier ***
  4179 
  4180 * added simplification meta rules:
  4181     (asm_)(full_)simplify: simpset -> thm -> thm;
  4182 
  4183 * simplifier.ML no longer part of Pure -- has to be loaded by object
  4184 logics (again);
  4185 
  4186 * added prems argument to simplification procedures;
  4187 
  4188 * HOL, FOL, ZF: added infix function `addsplits':
  4189   instead of `<simpset> setloop (split_tac <thms>)'
  4190   you can simply write `<simpset> addsplits <thms>'
  4191 
  4192 
  4193 *** Syntax ***
  4194 
  4195 * TYPE('a) syntax for type reflection terms;
  4196 
  4197 * no longer handles consts with name "" -- declare as 'syntax' instead;
  4198 
  4199 * pretty printer: changed order of mixfix annotation preference (again!);
  4200 
  4201 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  4202 
  4203 
  4204 *** HOL ***
  4205 
  4206 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4207   with `addloop' of the simplifier to faciliate case splitting in premises.
  4208 
  4209 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  4210 
  4211 * HOL/Auth: new protocol proofs including some for the Internet
  4212   protocol TLS;
  4213 
  4214 * HOL/Map: new theory of `maps' a la VDM;
  4215 
  4216 * HOL/simplifier: simplification procedures nat_cancel_sums for
  4217 cancelling out common nat summands from =, <, <= (in)equalities, or
  4218 differences; simplification procedures nat_cancel_factor for
  4219 cancelling common factor from =, <, <= (in)equalities over natural
  4220 sums; nat_cancel contains both kinds of procedures, it is installed by
  4221 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  4222 
  4223 * HOL/simplifier: terms of the form
  4224   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  4225   are rewritten to
  4226   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  4227   and those of the form
  4228   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  4229   are rewritten to
  4230   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  4231 
  4232 * HOL/datatype
  4233   Each datatype `t' now comes with a theorem `split_t_case' of the form
  4234 
  4235   P(t_case f1 ... fn x) =
  4236      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  4237         ...
  4238        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  4239      )
  4240 
  4241   and a theorem `split_t_case_asm' of the form
  4242 
  4243   P(t_case f1 ... fn x) =
  4244     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  4245         ...
  4246        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  4247      )
  4248   which can be added to a simpset via `addsplits'. The existing theorems
  4249   expand_list_case and expand_option_case have been renamed to
  4250   split_list_case and split_option_case.
  4251 
  4252 * HOL/Arithmetic:
  4253   - `pred n' is automatically converted to `n-1'.
  4254     Users are strongly encouraged not to use `pred' any longer,
  4255     because it will disappear altogether at some point.
  4256   - Users are strongly encouraged to write "0 < n" rather than
  4257     "n ~= 0". Theorems and proof tools have been modified towards this
  4258     `standard'.
  4259 
  4260 * HOL/Lists:
  4261   the function "set_of_list" has been renamed "set" (and its theorems too);
  4262   the function "nth" now takes its arguments in the reverse order and
  4263   has acquired the infix notation "!" as in "xs!n".
  4264 
  4265 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  4266 
  4267 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  4268   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  4269 
  4270 * HOL/record: extensible records with schematic structural subtyping
  4271 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  4272 still lacks various theorems and concrete record syntax;
  4273 
  4274 
  4275 *** HOLCF ***
  4276 
  4277 * removed "axioms" and "generated by" sections;
  4278 
  4279 * replaced "ops" section by extended "consts" section, which is capable of
  4280   handling the continuous function space "->" directly;
  4281 
  4282 * domain package:
  4283   . proves theorems immediately and stores them in the theory,
  4284   . creates hierachical name space,
  4285   . now uses normal mixfix annotations (instead of cinfix...),
  4286   . minor changes to some names and values (for consistency),
  4287   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  4288   . separator between mutual domain defs: changed "," to "and",
  4289   . improved handling of sort constraints;  now they have to
  4290     appear on the left-hand side of the equations only;
  4291 
  4292 * fixed LAM <x,y,zs>.b syntax;
  4293 
  4294 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  4295 adm (%x. P (t x)), where P is chainfinite and t continuous;
  4296 
  4297 
  4298 *** FOL and ZF ***
  4299 
  4300 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4301   with `addloop' of the simplifier to faciliate case splitting in premises.
  4302 
  4303 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  4304 in HOL, they strip ALL and --> from proved theorems;
  4305 
  4306 
  4307 
  4308 New in Isabelle94-8 (May 1997)
  4309 ------------------------------
  4310 
  4311 *** General Changes ***
  4312 
  4313 * new utilities to build / run / maintain Isabelle etc. (in parts
  4314 still somewhat experimental); old Makefiles etc. still functional;
  4315 
  4316 * new 'Isabelle System Manual';
  4317 
  4318 * INSTALL text, together with ./configure and ./build scripts;
  4319 
  4320 * reimplemented type inference for greater efficiency, better error
  4321 messages and clean internal interface;
  4322 
  4323 * prlim command for dealing with lots of subgoals (an easier way of
  4324 setting goals_limit);
  4325 
  4326 
  4327 *** Syntax ***
  4328 
  4329 * supports alternative (named) syntax tables (parser and pretty
  4330 printer); internal interface is provided by add_modesyntax(_i);
  4331 
  4332 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  4333 be used in conjunction with the Isabelle symbol font; uses the
  4334 "symbols" syntax table;
  4335 
  4336 * added token_translation interface (may translate name tokens in
  4337 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  4338 the current print_mode); IMPORTANT: user print translation functions
  4339 are responsible for marking newly introduced bounds
  4340 (Syntax.mark_boundT);
  4341 
  4342 * token translations for modes "xterm" and "xterm_color" that display
  4343 names in bold, underline etc. or colors (which requires a color
  4344 version of xterm);
  4345 
  4346 * infixes may now be declared with names independent of their syntax;
  4347 
  4348 * added typed_print_translation (like print_translation, but may
  4349 access type of constant);
  4350 
  4351 
  4352 *** Classical Reasoner ***
  4353 
  4354 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  4355 some limitations.  Blast_tac...
  4356   + ignores addss, addbefore, addafter; this restriction is intrinsic
  4357   + ignores elimination rules that don't have the correct format
  4358         (the conclusion MUST be a formula variable)
  4359   + ignores types, which can make HOL proofs fail
  4360   + rules must not require higher-order unification, e.g. apply_type in ZF
  4361     [message "Function Var's argument not a bound variable" relates to this]
  4362   + its proof strategy is more general but can actually be slower
  4363 
  4364 * substitution with equality assumptions no longer permutes other
  4365 assumptions;
  4366 
  4367 * minor changes in semantics of addafter (now called addaltern); renamed
  4368 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  4369 (and access functions for it);
  4370 
  4371 * improved combination of classical reasoner and simplifier:
  4372   + functions for handling clasimpsets
  4373   + improvement of addss: now the simplifier is called _after_ the
  4374     safe steps.
  4375   + safe variant of addss called addSss: uses safe simplifications
  4376     _during_ the safe steps. It is more complete as it allows multiple
  4377     instantiations of unknowns (e.g. with slow_tac).
  4378 
  4379 *** Simplifier ***
  4380 
  4381 * added interface for simplification procedures (functions that
  4382 produce *proven* rewrite rules on the fly, depending on current
  4383 redex);
  4384 
  4385 * ordering on terms as parameter (used for ordered rewriting);
  4386 
  4387 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  4388 
  4389 * the solver is now split into a safe and an unsafe part.
  4390 This should be invisible for the normal user, except that the
  4391 functions setsolver and addsolver have been renamed to setSolver and
  4392 addSolver; added safe_asm_full_simp_tac;
  4393 
  4394 
  4395 *** HOL ***
  4396 
  4397 * a generic induction tactic `induct_tac' which works for all datatypes and
  4398 also for type `nat';
  4399 
  4400 * a generic case distinction tactic `exhaust_tac' which works for all
  4401 datatypes and also for type `nat';
  4402 
  4403 * each datatype comes with a function `size';
  4404 
  4405 * patterns in case expressions allow tuple patterns as arguments to
  4406 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  4407 
  4408 * primrec now also works with type nat;
  4409 
  4410 * recdef: a new declaration form, allows general recursive functions to be
  4411 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  4412 
  4413 * the constant for negation has been renamed from "not" to "Not" to
  4414 harmonize with FOL, ZF, LK, etc.;
  4415 
  4416 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  4417 infinite lists;
  4418 
  4419 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  4420 
  4421 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  4422 problems in commutative rings, using axiomatic type classes for + and *;
  4423 
  4424 * more examples in HOL/MiniML and HOL/Auth;
  4425 
  4426 * more default rewrite rules for quantifiers, union/intersection;
  4427 
  4428 * a new constant `arbitrary == @x.False';
  4429 
  4430 * HOLCF/IOA replaces old HOL/IOA;
  4431 
  4432 * HOLCF changes: derived all rules and arities
  4433   + axiomatic type classes instead of classes
  4434   + typedef instead of faking type definitions
  4435   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  4436   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  4437   + eliminated the types void, one, tr
  4438   + use unit lift and bool lift (with translations) instead of one and tr
  4439   + eliminated blift from Lift3.thy (use Def instead of blift)
  4440   all eliminated rules are derived as theorems --> no visible changes ;
  4441 
  4442 
  4443 *** ZF ***
  4444 
  4445 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  4446 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  4447 as ZF_cs addSIs [equalityI];
  4448 
  4449 
  4450 
  4451 New in Isabelle94-7 (November 96)
  4452 ---------------------------------
  4453 
  4454 * allowing negative levels (as offsets) in prlev and choplev;
  4455 
  4456 * super-linear speedup for large simplifications;
  4457 
  4458 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  4459 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  4460 FAIL); can suppress it using the command Delsimps (ex_simps @
  4461 all_simps); De Morgan laws are also now included, by default;
  4462 
  4463 * improved printing of ==>  :  ~:
  4464 
  4465 * new object-logic "Sequents" adds linear logic, while replacing LK
  4466 and Modal (thanks to Sara Kalvala);
  4467 
  4468 * HOL/Auth: correctness proofs for authentication protocols;
  4469 
  4470 * HOL: new auto_tac combines rewriting and classical reasoning (many
  4471 examples on HOL/Auth);
  4472 
  4473 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  4474 the rewriter and classical reasoner simultaneously;
  4475 
  4476 * function uresult no longer returns theorems in "standard" format;
  4477 regain previous version by: val uresult = standard o uresult;
  4478 
  4479 
  4480 
  4481 New in Isabelle94-6
  4482 -------------------
  4483 
  4484 * oracles -- these establish an interface between Isabelle and trusted
  4485 external reasoners, which may deliver results as theorems;
  4486 
  4487 * proof objects (in particular record all uses of oracles);
  4488 
  4489 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  4490 
  4491 * "constdefs" section in theory files;
  4492 
  4493 * "primrec" section (HOL) no longer requires names;
  4494 
  4495 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  4496 
  4497 
  4498 
  4499 New in Isabelle94-5
  4500 -------------------
  4501 
  4502 * reduced space requirements;
  4503 
  4504 * automatic HTML generation from theories;
  4505 
  4506 * theory files no longer require "..." (quotes) around most types;
  4507 
  4508 * new examples, including two proofs of the Church-Rosser theorem;
  4509 
  4510 * non-curried (1994) version of HOL is no longer distributed;
  4511 
  4512 
  4513 
  4514 New in Isabelle94-4
  4515 -------------------
  4516 
  4517 * greatly reduced space requirements;
  4518 
  4519 * theory files (.thy) no longer require \...\ escapes at line breaks;
  4520 
  4521 * searchable theorem database (see the section "Retrieving theorems" on
  4522 page 8 of the Reference Manual);
  4523 
  4524 * new examples, including Grabczewski's monumental case study of the
  4525 Axiom of Choice;
  4526 
  4527 * The previous version of HOL renamed to Old_HOL;
  4528 
  4529 * The new version of HOL (previously called CHOL) uses a curried syntax
  4530 for functions.  Application looks like f a b instead of f(a,b);
  4531 
  4532 * Mutually recursive inductive definitions finally work in HOL;
  4533 
  4534 * In ZF, pattern-matching on tuples is now available in all abstractions and
  4535 translates to the operator "split";
  4536 
  4537 
  4538 
  4539 New in Isabelle94-3
  4540 -------------------
  4541 
  4542 * new infix operator, addss, allowing the classical reasoner to
  4543 perform simplification at each step of its search.  Example:
  4544         fast_tac (cs addss ss)
  4545 
  4546 * a new logic, CHOL, the same as HOL, but with a curried syntax
  4547 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  4548 look like (a,b) instead of <a,b>;
  4549 
  4550 * PLEASE NOTE: CHOL will eventually replace HOL!
  4551 
  4552 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  4553 It translates to the operator "split".  A new theory of integers is available;
  4554 
  4555 * In ZF, integer numerals now denote two's-complement binary integers.
  4556 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  4557 
  4558 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  4559 of the Axiom of Choice;
  4560 
  4561 
  4562 
  4563 New in Isabelle94-2
  4564 -------------------
  4565 
  4566 * Significantly faster resolution;
  4567 
  4568 * the different sections in a .thy file can now be mixed and repeated
  4569 freely;
  4570 
  4571 * Database of theorems for FOL, HOL and ZF.  New
  4572 commands including qed, qed_goal and bind_thm store theorems in the database.
  4573 
  4574 * Simple database queries: return a named theorem (get_thm) or all theorems of
  4575 a given theory (thms_of), or find out what theory a theorem was proved in
  4576 (theory_of_thm);
  4577 
  4578 * Bugs fixed in the inductive definition and datatype packages;
  4579 
  4580 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  4581 and HOL_dup_cs obsolete;
  4582 
  4583 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  4584 have been removed;
  4585 
  4586 * Simpler definition of function space in ZF;
  4587 
  4588 * new results about cardinal and ordinal arithmetic in ZF;
  4589 
  4590 * 'subtype' facility in HOL for introducing new types as subsets of existing
  4591 types;
  4592 
  4593 
  4594 $Id$