NEWS
author wenzelm
Wed Feb 28 22:05:41 2007 +0100 (2007-02-28)
changeset 22376 b711c2ad7507
parent 22316 f662831459de
child 22384 33a46e6c7f04
permissions -rw-r--r--
added @{const_name}, @{const_syntax};
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Theory syntax: the header format ``theory A = B + C:'' has been
    10 discontinued in favour of ``theory A imports B C begin''.  Use isatool
    11 fixheaders to convert existing theory files.  INCOMPATIBILITY.
    12 
    13 * Theory syntax: the old non-Isar theory file format has been
    14 discontinued altogether.  Note that ML proof scripts may still be used
    15 with Isar theories; migration is usually quite simple with the ML
    16 function use_legacy_bindings.  INCOMPATIBILITY.
    17 
    18 * Theory syntax: some popular names (e.g. "class", "fun", "help",
    19 "if") are now keywords.  INCOMPATIBILITY, use double quotes.
    20 
    21 * Legacy goal package: reduced interface to the bare minimum required
    22 to keep existing proof scripts running.  Most other user-level
    23 functions are now part of the OldGoals structure, which is *not* open
    24 by default (consider isatool expandshort before open OldGoals).
    25 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
    26 these tend to cause confusion about the actual goal (!) context being
    27 used here, which is not necessarily the same as the_context().
    28 
    29 * Command 'find_theorems': support "*" wildcard in "name:" criterion.
    30 
    31 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
    32 by default, which means that "prems" (and also "fixed variables") are
    33 suppressed from proof state output.  Note that the ProofGeneral
    34 settings mechanism allows to change and save options persistently, but
    35 older versions of Isabelle will fail to start up if a negative prems
    36 limit is imposed.
    37 
    38 * Local theory targets may be specified by non-nested blocks of
    39 ``context/locale/class ... begin'' followed by ``end''.  The body may
    40 contain definitions, theorems etc., including any derived mechanism
    41 that has been implemented on top of these primitives.  This concept
    42 generalizes the existing ``theorem (in ...)'' towards more versatility
    43 and scalability.
    44 
    45 * Proof General interface: proper undo of final 'end' command;
    46 discontinued Isabelle/classic mode (ML proof scripts).
    47 
    48 
    49 *** Document preparation ***
    50 
    51 * Added antiquotation @{theory name} which prints the given name,
    52 after checking that it refers to a valid ancestor theory in the
    53 current context.
    54 
    55 * Added antiquotations @{ML_type text} and @{ML_struct text} which
    56 check the given source text as ML type/structure, printing verbatim.
    57 
    58 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
    59 "c args == rhs" given in the current context.  (Any number of
    60 arguments may be given on the LHS.)
    61 
    62 
    63 
    64 *** Pure ***
    65 
    66 * class_package.ML offers a combination of axclasses and locales to
    67 achieve Haskell-like type classes in Isabelle. See
    68 HOL/ex/Classpackage.thy for examples.
    69 
    70 * Yet another code generator framework allows to generate executable
    71 code for ML and Haskell (including "class"es). A short usage sketch:
    72 
    73     internal compilation:
    74         code_gen <list of constants (term syntax)> (SML #)
    75     writing SML code to a file:
    76         code_gen <list of constants (term syntax)> (SML <filename>)
    77     writing Haskell code to a bunch of files:
    78         code_gen <list of constants (term syntax)> (Haskell <filename>)
    79 
    80 Reasonable default setup of framework in HOL/Main.
    81 
    82 Theorem attributs for selecting and transforming function equations theorems:
    83 
    84     [code fun]:       select a theorem as function equation for a specific constant
    85     [code nofun]:     deselect a theorem as function equation for a specific constant
    86     [code inline]:    select an equation theorem for unfolding (inlining) in place
    87     [code noinline]:  deselect an equation theorem for unfolding (inlining) in place
    88 
    89 User-defined serializations (target in {SML, Haskell}):
    90 
    91     code_const <and-list of constants (term syntax)>
    92       {(target) <and-list of const target syntax>}+
    93 
    94     code_type <and-list of type constructors>
    95       {(target) <and-list of type target syntax>}+
    96 
    97     code_instance <and-list of instances>
    98       {(target)}+
    99         where instance ::= <type constructor> :: <class>
   100 
   101     code_class <and_list of classes>
   102       {(target) <and-list of class target syntax>}+
   103         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
   104 
   105 For code_instance and code_class, target SML is silently ignored.
   106 
   107 See HOL theories and HOL/ex/Code*.thy for usage examples.  Doc/Isar/Advanced/Codegen/
   108 provides a tutorial.
   109 
   110 * Command 'no_translations' removes translation rules from theory
   111 syntax.
   112 
   113 * Overloaded definitions are now actually checked for acyclic
   114 dependencies.  The overloading scheme is slightly more general than
   115 that of Haskell98, although Isabelle does not demand an exact
   116 correspondence to type class and instance declarations.
   117 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
   118 exotic versions of overloading -- at the discretion of the user!
   119 
   120 Polymorphic constants are represented via type arguments, i.e. the
   121 instantiation that matches an instance against the most general
   122 declaration given in the signature.  For example, with the declaration
   123 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
   124 as c(nat).  Overloading is essentially simultaneous structural
   125 recursion over such type arguments.  Incomplete specification patterns
   126 impose global constraints on all occurrences, e.g. c('a * 'a) on the
   127 LHS means that more general c('a * 'b) will be disallowed on any RHS.
   128 Command 'print_theory' outputs the normalized system of recursive
   129 equations, see section "definitions".
   130 
   131 * Isar: improper proof element 'guess' is like 'obtain', but derives
   132 the obtained context from the course of reasoning!  For example:
   133 
   134   assume "EX x y. A x & B y"   -- "any previous fact"
   135   then guess x and y by clarify
   136 
   137 This technique is potentially adventurous, depending on the facts and
   138 proof tools being involved here.
   139 
   140 * Isar: known facts from the proof context may be specified as literal
   141 propositions, using ASCII back-quote syntax.  This works wherever
   142 named facts used to be allowed so far, in proof commands, proof
   143 methods, attributes etc.  Literal facts are retrieved from the context
   144 according to unification of type and term parameters.  For example,
   145 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
   146 theorems in the current context, then these are valid literal facts:
   147 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
   148 
   149 There is also a proof method "fact" which does the same composition
   150 for explicit goal states, e.g. the following proof texts coincide with
   151 certain special cases of literal facts:
   152 
   153   have "A" by fact                 ==  note `A`
   154   have "A ==> B" by fact           ==  note `A ==> B`
   155   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
   156   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
   157 
   158 * Isar: ":" (colon) is no longer a symbolic identifier character in
   159 outer syntax.  Thus symbolic identifiers may be used without
   160 additional white space in declarations like this: ``assume *: A''.
   161 
   162 * Isar: 'print_facts' prints all local facts of the current context,
   163 both named and unnamed ones.
   164 
   165 * Isar: 'def' now admits simultaneous definitions, e.g.:
   166 
   167   def x == "t" and y == "u"
   168 
   169 * Isar: added command 'unfolding', which is structurally similar to
   170 'using', but affects both the goal state and facts by unfolding given
   171 rewrite rules.  Thus many occurrences of the 'unfold' method or
   172 'unfolded' attribute may be replaced by first-class proof text.
   173 
   174 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
   175 and command 'unfolding' now all support object-level equalities
   176 (potentially conditional).  The underlying notion of rewrite rule is
   177 analogous to the 'rule_format' attribute, but *not* that of the
   178 Simplifier (which is usually more generous).
   179 
   180 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
   181 method expression within a sandbox consisting of the first N
   182 sub-goals, which need to exist.  For example, ``simp_all [3]''
   183 simplifies the first three sub-goals, while (rule foo, simp_all)[]
   184 simplifies all new goals that emerge from applying rule foo to the
   185 originally first one.
   186 
   187 * Isar: schematic goals are no longer restricted to higher-order
   188 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
   189 expected.
   190 
   191 * Isar: the conclusion of a long theorem statement is now either
   192 'shows' (a simultaneous conjunction, as before), or 'obtains'
   193 (essentially a disjunction of cases with local parameters and
   194 assumptions).  The latter allows to express general elimination rules
   195 adequately; in this notation common elimination rules look like this:
   196 
   197   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
   198     assumes "EX x. P x"
   199     obtains x where "P x"
   200 
   201   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
   202     assumes "A & B"
   203     obtains A and B
   204 
   205   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
   206     assumes "A | B"
   207     obtains
   208       A
   209     | B
   210 
   211 The subsequent classical rules even refer to the formal "thesis"
   212 explicitly:
   213 
   214   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
   215     obtains "~ thesis"
   216 
   217   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
   218     obtains "thesis ==> something"
   219 
   220 The actual proof of an 'obtains' statement is analogous to that of the
   221 Isar proof element 'obtain', only that there may be several cases.
   222 Optional case names may be specified in parentheses; these will be
   223 available both in the present proof and as annotations in the
   224 resulting rule, for later use with the 'cases' method (cf. attribute
   225 case_names).
   226 
   227 * Isar: the assumptions of a long theorem statement are available as
   228 "assms" fact in the proof context.  This is more appropriate than the
   229 (historical) "prems", which refers to all assumptions of the current
   230 context, including those from the target locale, proof body etc.
   231 
   232 * Isar: 'print_statement' prints theorems from the current theory or
   233 proof context in long statement form, according to the syntax of a
   234 top-level lemma.
   235 
   236 * Isar: 'obtain' takes an optional case name for the local context
   237 introduction rule (default "that").
   238 
   239 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
   240 explicit (is "_ ==> ?foo") in the rare cases where this still happens
   241 to occur.
   242 
   243 * Pure: syntax "CONST name" produces a fully internalized constant
   244 according to the current context.  This is particularly useful for
   245 syntax translations that should refer to internal constant
   246 representations independently of name spaces.
   247 
   248 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
   249 instead of "FOO ". This allows multiple binder declarations to coexist
   250 in the same context.  INCOMPATIBILITY.
   251 
   252 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
   253 primitive that also works in a locale context (both for constants and
   254 fixed variables).  Type declaration and internal syntactic
   255 representation of given constants retrieved from the context.
   256 
   257 * Isar/locales: new derived specification elements 'axiomatization',
   258 'definition', 'abbreviation', which support type-inference, admit
   259 object-level specifications (equality, equivalence).  See also the
   260 isar-ref manual.  Examples:
   261 
   262   axiomatization
   263     eq  (infix "===" 50) where
   264     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
   265 
   266   definition "f x y = x + y + 1"
   267   definition g where "g x = f x x"
   268 
   269   abbreviation
   270     neq  (infix "=!=" 50) where
   271     "x =!= y == ~ (x === y)"
   272 
   273 These specifications may be also used in a locale context.  Then the
   274 constants being introduced depend on certain fixed parameters, and the
   275 constant name is qualified by the locale base name.  An internal
   276 abbreviation takes care for convenient input and output, making the
   277 parameters implicit and using the original short name.  See also
   278 HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
   279 entities from a monomorphic theory.
   280 
   281 Presently, abbreviations are only available 'in' a target locale, but
   282 not inherited by general import expressions.  Also note that
   283 'abbreviation' may be used as a type-safe replacement for 'syntax' +
   284 'translations' in common applications.
   285 
   286 Concrete syntax is attached to specified constants in internal form,
   287 independently of name spaces.  The parse tree representation is
   288 slightly different -- use 'notation' instead of raw 'syntax', and
   289 'translations' with explicit "CONST" markup to accommodate this.
   290 
   291 * Pure: command 'print_abbrevs' prints all constant abbreviations of
   292 the current context.  Print mode "no_abbrevs" prevents inversion of
   293 abbreviations on output.
   294 
   295 * Isar/locales: improved parameter handling:
   296 - use of locales "var" and "struct" no longer necessary;
   297 - parameter renamings are no longer required to be injective.
   298   This enables, for example, to define a locale for endomorphisms thus:
   299   locale endom = homom mult mult h.
   300 
   301 * Isar/locales: changed the way locales with predicates are defined.
   302 Instead of accumulating the specification, the imported expression is
   303 now an interpretation.  INCOMPATIBILITY: different normal form of
   304 locale expressions.  In particular, in interpretations of locales with
   305 predicates, goals repesenting already interpreted fragments are not
   306 removed automatically.  Use methods `intro_locales' and
   307 `unfold_locales'; see below.
   308 
   309 * Isar/locales: new methods `intro_locales' and `unfold_locales'
   310 provide backward reasoning on locales predicates.  The methods are
   311 aware of interpretations and discharge corresponding goals.
   312 `intro_locales' is less aggressive then `unfold_locales' and does not
   313 unfold predicates to assumptions.
   314 
   315 * Isar/locales: the order in which locale fragments are accumulated
   316 has changed.  This enables to override declarations from fragments due
   317 to interpretations -- for example, unwanted simp rules.
   318 
   319 * Provers/induct: improved internal context management to support
   320 local fixes and defines on-the-fly.  Thus explicit meta-level
   321 connectives !! and ==> are rarely required anymore in inductive goals
   322 (using object-logic connectives for this purpose has been long
   323 obsolete anyway).  The subsequent proof patterns illustrate advanced
   324 techniques of natural induction; general datatypes and inductive sets
   325 work analogously (see also src/HOL/Lambda for realistic examples).
   326 
   327 (1) This is how to ``strengthen'' an inductive goal wrt. certain
   328 parameters:
   329 
   330   lemma
   331     fixes n :: nat and x :: 'a
   332     assumes a: "A n x"
   333     shows "P n x"
   334     using a                     -- {* make induct insert fact a *}
   335   proof (induct n arbitrary: x) -- {* generalize goal to "!!x. A n x ==> P n x" *}
   336     case 0
   337     show ?case sorry
   338   next
   339     case (Suc n)
   340     note `!!x. A n x ==> P n x` -- {* induction hypothesis, according to induction rule *}
   341     note `A (Suc n) x`          -- {* induction premise, stemming from fact a *}
   342     show ?case sorry
   343   qed
   344 
   345 (2) This is how to perform induction over ``expressions of a certain
   346 form'', using a locally defined inductive parameter n == "a x"
   347 together with strengthening (the latter is usually required to get
   348 sufficiently flexible induction hypotheses):
   349 
   350   lemma
   351     fixes a :: "'a => nat"
   352     assumes a: "A (a x)"
   353     shows "P (a x)"
   354     using a
   355   proof (induct n == "a x" arbitrary: x)
   356     ...
   357 
   358 See also HOL/Isar_examples/Puzzle.thy for an application of the this
   359 particular technique.
   360 
   361 (3) This is how to perform existential reasoning ('obtains' or
   362 'obtain') by induction, while avoiding explicit object-logic
   363 encodings:
   364 
   365   lemma
   366     fixes n :: nat
   367     obtains x :: 'a where "P n x" and "Q n x"
   368   proof (induct n arbitrary: thesis)
   369     case 0
   370     obtain x where "P 0 x" and "Q 0 x" sorry
   371     then show thesis by (rule 0)
   372   next
   373     case (Suc n)
   374     obtain x where "P n x" and "Q n x" by (rule Suc.hyps)
   375     obtain x where "P (Suc n) x" and "Q (Suc n) x" sorry
   376     then show thesis by (rule Suc.prems)
   377   qed
   378 
   379 Here the 'arbitrary: thesis' specification essentially modifies the
   380 scope of the formal thesis parameter, in order to the get the whole
   381 existence statement through the induction as expected.
   382 
   383 * Provers/induct: mutual induction rules are now specified as a list
   384 of rule sharing the same induction cases.  HOL packages usually
   385 provide foo_bar.inducts for mutually defined items foo and bar
   386 (e.g. inductive sets or datatypes).  INCOMPATIBILITY, users need to
   387 specify mutual induction rules differently, i.e. like this:
   388 
   389   (induct rule: foo_bar.inducts)
   390   (induct set: foo bar)
   391   (induct type: foo bar)
   392 
   393 The ML function ProjectRule.projections turns old-style rules into the
   394 new format.
   395 
   396 * Provers/induct: improved handling of simultaneous goals.  Instead of
   397 introducing object-level conjunction, the statement is now split into
   398 several conclusions, while the corresponding symbolic cases are
   399 nested accordingly.  INCOMPATIBILITY, proofs need to be structured
   400 explicitly.  For example:
   401 
   402   lemma
   403     fixes n :: nat
   404     shows "P n" and "Q n"
   405   proof (induct n)
   406     case 0 case 1
   407     show "P 0" sorry
   408   next
   409     case 0 case 2
   410     show "Q 0" sorry
   411   next
   412     case (Suc n) case 1
   413     note `P n` and `Q n`
   414     show "P (Suc n)" sorry
   415   next
   416     case (Suc n) case 2
   417     note `P n` and `Q n`
   418     show "Q (Suc n)" sorry
   419   qed
   420 
   421 The split into subcases may be deferred as follows -- this is
   422 particularly relevant for goal statements with local premises.
   423 
   424   lemma
   425     fixes n :: nat
   426     shows "A n ==> P n" and "B n ==> Q n"
   427   proof (induct n)
   428     case 0
   429     {
   430       case 1
   431       note `A 0`
   432       show "P 0" sorry
   433     next
   434       case 2
   435       note `B 0`
   436       show "Q 0" sorry
   437     }
   438   next
   439     case (Suc n)
   440     note `A n ==> P n` and `B n ==> Q n`
   441     {
   442       case 1
   443       note `A (Suc n)`
   444       show "P (Suc n)" sorry
   445     next
   446       case 2
   447       note `B (Suc n)`
   448       show "Q (Suc n)" sorry
   449     }
   450   qed
   451 
   452 If simultaneous goals are to be used with mutual rules, the statement
   453 needs to be structured carefully as a two-level conjunction, using
   454 lists of propositions separated by 'and':
   455 
   456   lemma
   457     shows "a : A ==> P1 a"
   458           "a : A ==> P2 a"
   459       and "b : B ==> Q1 b"
   460           "b : B ==> Q2 b"
   461           "b : B ==> Q3 b"
   462   proof (induct set: A B)
   463 
   464 * Provers/induct: support coinduction as well.  See
   465 src/HOL/Library/Coinductive_List.thy for various examples.
   466 
   467 * Attribute "symmetric" produces result with standardized schematic
   468 variables (index 0).  Potential INCOMPATIBILITY.
   469 
   470 * Simplifier: by default the simplifier trace only shows top level
   471 rewrites now. That is, trace_simp_depth_limit is set to 1 by
   472 default. Thus there is less danger of being flooded by the trace. The
   473 trace indicates where parts have been suppressed.
   474   
   475 * Provers/classical: removed obsolete classical version of elim_format
   476 attribute; classical elim/dest rules are now treated uniformly when
   477 manipulating the claset.
   478 
   479 * Provers/classical: stricter checks to ensure that supplied intro,
   480 dest and elim rules are well-formed; dest and elim rules must have at
   481 least one premise.
   482 
   483 * Provers/classical: attributes dest/elim/intro take an optional
   484 weight argument for the rule (just as the Pure versions).  Weights are
   485 ignored by automated tools, but determine the search order of single
   486 rule steps.
   487 
   488 * Syntax: input syntax now supports dummy variable binding "%_. b",
   489 where the body does not mention the bound variable.  Note that dummy
   490 patterns implicitly depend on their context of bounds, which makes
   491 "{_. _}" match any set comprehension as expected.  Potential
   492 INCOMPATIBILITY -- parse translations need to cope with syntactic
   493 constant "_idtdummy" in the binding position.
   494 
   495 * Syntax: removed obsolete syntactic constant "_K" and its associated
   496 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
   497 for example "A -> B" => "Pi A (%_. B)".
   498 
   499 * Pure: 'class_deps' command visualizes the subclass relation, using
   500 the graph browser tool.
   501 
   502 * Pure: 'print_theory' now suppresses entities with internal name
   503 (trailing "_") by default; use '!' option for full details.
   504 
   505 
   506 *** HOL ***
   507 
   508 * Addes class (axclass + locale) "preorder" as superclass of "order";
   509 potential INCOMPATIBILITY: order of proof goals in order/linorder instance
   510 proofs changed.
   511 
   512 * Dropped lemma duplicate def_imp_eq in favor of meta_eq_to_obj_eq.
   513 INCOMPATIBILITY.
   514 
   515 * Dropped lemma duplicate if_def2 in favor of if_bool_eq_conj.
   516 INCOMPATIBILITY.
   517 
   518 * Added syntactic class "size"; overloaded constant "size" now has
   519 type "'a::size ==> bool"
   520 
   521 * Renamed constants "Divides.op div", "Divides.op mod" and "Divides.op
   522 dvd" to "Divides.div", "Divides.mod" and "Divides.dvd". INCOMPATIBILITY.
   523 
   524 * Added method "lexicographic_order" automatically synthesizes
   525 termination relations as lexicographic combinations of size measures
   526 -- 'function' package.
   527 
   528 * HOL/records: generalised field-update to take a function on the
   529 field rather than the new value: r(|A := x|) is translated to A_update
   530 (K x) r The K-combinator that is internally used is called K_record.
   531 INCOMPATIBILITY: Usage of the plain update functions has to be
   532 adapted.
   533  
   534 * axclass "semiring_0" now contains annihilation axioms x * 0 = 0 and
   535 0 * x = 0, which are required for a semiring.  Richer structures do
   536 not inherit from semiring_0 anymore, because this property is a
   537 theorem there, not an axiom.  INCOMPATIBILITY: In instances of
   538 semiring_0, there is more to prove, but this is mostly trivial.
   539 
   540 * axclass "recpower" was generalized to arbitrary monoids, not just
   541 commutative semirings.  INCOMPATIBILITY: If you use recpower and need
   542 commutativity or a semiring property, add the corresponding classes.
   543 
   544 * Unified locale partial_order with class definition (cf. theory
   545 Orderings), added parameter ``less''.  INCOMPATIBILITY.
   546 
   547 * Constant "List.list_all2" in List.thy now uses authentic syntax.
   548 INCOMPATIBILITY: translations containing list_all2 may go wrong.  On
   549 Isar level, use abbreviations instead.
   550 
   551 * Renamed constant "List.op mem" to "List.memberl" INCOMPATIBILITY:
   552 rarely occuring name references (e.g. ``List.op mem.simps'') require
   553 renaming (e.g. ``List.memberl.simps'').
   554 
   555 * Renamed constants "0" to "HOL.zero" and "1" to "HOL.one".
   556 INCOMPATIBILITY.
   557 
   558 * Added theory Code_Generator providing class 'eq', allowing for code
   559 generation with polymorphic equality.
   560 
   561 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
   562 been abandoned in favour of plain 'int'. INCOMPATIBILITY --
   563 significant changes for setting up numeral syntax for types:
   564 
   565   - new constants Numeral.pred and Numeral.succ instead
   566       of former Numeral.bin_pred and Numeral.bin_succ.
   567   - Use integer operations instead of bin_add, bin_mult and so on.
   568   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
   569   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
   570 
   571 See HOL/Integ/IntArith.thy for an example setup.
   572 
   573 * New top level command 'normal_form' computes the normal form of a
   574 term that may contain free variables. For example ``normal_form
   575 "rev[a,b,c]"'' produces ``[b,c,a]'' (without proof).  This command is
   576 suitable for heavy-duty computations because the functions are
   577 compiled to ML first.
   578 
   579 * Alternative iff syntax "A <-> B" for equality on bool (with priority
   580 25 like -->); output depends on the "iff" print_mode, the default is
   581 "A = B" (with priority 50).
   582 
   583 * Renamed constants in HOL.thy and Orderings.thy:
   584     op +   ~> HOL.plus
   585     op -   ~> HOL.minus
   586     uminus ~> HOL.uminus
   587     op *   ~> HOL.times
   588     op <   ~> Orderings.less
   589     op <=  ~> Orderings.less_eq
   590 
   591 Adaptions may be required in the following cases:
   592 
   593 a) User-defined constants using any of the names "plus", "minus", "times",
   594 "less" or "less_eq". The standard syntax translations for "+", "-" and "*"
   595 may go wrong.
   596 INCOMPATIBILITY: use more specific names.
   597 
   598 b) Variables named "plus", "minus", "times", "less", "less_eq"
   599 INCOMPATIBILITY: use more specific names.
   600 
   601 c) Permutative equations (e.g. "a + b = b + a")
   602 Since the change of names also changes the order of terms, permutative
   603 rewrite rules may get applied in a different order. Experience shows that
   604 this is rarely the case (only two adaptions in the whole Isabelle
   605 distribution).
   606 INCOMPATIBILITY: rewrite proofs
   607 
   608 d) ML code directly refering to constant names
   609 This in general only affects hand-written proof tactics, simprocs and so on.
   610 INCOMPATIBILITY: grep your sourcecode and replace names.
   611 
   612 * Relations less (<) and less_eq (<=) are also available on type bool.
   613 Modified syntax to disallow nesting without explicit parentheses,
   614 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".
   615 
   616 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
   617 
   618 * Relation composition operator "op O" now has precedence 75 and binds
   619 stronger than union and intersection. INCOMPATIBILITY.
   620 
   621 * The old set interval syntax "{m..n(}" (and relatives) has been
   622 removed.  Use "{m..<n}" (and relatives) instead.
   623 
   624 * In the context of the assumption "~(s = t)" the Simplifier rewrites
   625 "t = s" to False (by simproc "neq_simproc").  For backward
   626 compatibility this can be disabled by ML "reset use_neq_simproc".
   627 
   628 * "m dvd n" where m and n are numbers is evaluated to True/False by
   629 simp.
   630 
   631 * Theorem Cons_eq_map_conv no longer declared as ``simp''.
   632 
   633 * Theorem setsum_mult renamed to setsum_right_distrib.
   634 
   635 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
   636 ``rule'' method.
   637 
   638 * Reimplemented methods ``sat'' and ``satx'', with several
   639 improvements: goals no longer need to be stated as "<prems> ==>
   640 False", equivalences (i.e. "=" on type bool) are handled, variable
   641 names of the form "lit_<n>" are no longer reserved, significant
   642 speedup.
   643 
   644 * Methods ``sat'' and ``satx'' can now replay MiniSat proof traces.
   645 zChaff is still supported as well.
   646 
   647 * 'inductive' and 'datatype': provide projections of mutual rules,
   648 bundled as foo_bar.inducts;
   649 
   650 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
   651 Library.
   652 
   653 * Library: moved theory Accessible_Part to main HOL.
   654 
   655 * Library: added theory Coinductive_List of potentially infinite lists
   656 as greatest fixed-point.
   657 
   658 * Library: added theory AssocList which implements (finite) maps as
   659 association lists.
   660 
   661 * Added proof method ``evaluation'' for efficiently solving a goal
   662 (i.e. a boolean expression) by compiling it to ML. The goal is
   663 "proved" (via an oracle) if it evaluates to True.
   664 
   665 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
   666 also when invoked by the simplifier.  This results in the simplifier
   667 being more powerful on arithmetic goals.  INCOMPATIBILITY.  Set
   668 fast_arith_split_limit to 0 to obtain the old behavior.
   669 
   670 * Support for hex (0x20) and binary (0b1001) numerals.
   671 
   672 * New method: reify eqs (t), where eqs are equations for an
   673 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
   674 parameter, computes a term s::'b and a list xs::'a list and proves the
   675 theorem I xs s = t. This is also known as reification or quoting. The
   676 resulting theorem is applied to the subgoal to substitute t with I xs
   677 s.  If t is omitted, the subgoal itself is reified.
   678 
   679 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
   680 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
   681 where f is supposed to be a computable function (in the sense of code
   682 generattion). The method uses reify to compute s and xs as above then
   683 applies corr_thm and uses normalization by evaluation to "prove" f s =
   684 r and finally gets the theorem t = r, which is again applied to the
   685 subgoal. An Example is available in HOL/ex/ReflectionEx.thy.
   686 
   687 * Reflection: Automatic refification now handels binding, an example
   688 is available in HOL/ex/ReflectionEx.thy
   689 
   690 
   691 *** HOL-Algebra ***
   692 
   693 * Formalisation of ideals and the quotient construction over rings.
   694 
   695 * Order and lattice theory no longer based on records.
   696 INCOMPATIBILITY.
   697 
   698 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
   699 greatest_closed.  INCOMPATIBILITY.
   700 
   701 * Method algebra is now set up via an attribute.  For examples see
   702 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
   703 of algebraic structures.
   704 
   705 * Renamed theory CRing to Ring.
   706 
   707 
   708 *** HOL-Complex ***
   709 
   710 * Theory Real: new method ferrack implements quantifier elimination
   711 for linear arithmetic over the reals. The quantifier elimination
   712 feature is used only for decision, for compatibility with arith. This
   713 means a goal is either solved or left unchanged, no simplification.
   714 
   715 * Real: New axiomatic classes formalize real normed vector spaces and
   716 algebras, using new overloaded constants scaleR :: real => 'a => 'a
   717 and norm :: 'a => real.
   718 
   719 * Real: New constant of_real :: real => 'a::real_algebra_1 injects
   720 from reals into other types. The overloaded constant Reals :: 'a set
   721 is now defined as range of_real; potential INCOMPATIBILITY.
   722 
   723 * Hyperreal: Several constants that previously worked only for the
   724 reals have been generalized, so they now work over arbitrary vector
   725 spaces. Type annotations may need to be added in some cases; potential
   726 INCOMPATIBILITY.
   727 
   728   Infinitesimal  :: ('a::real_normed_vector) star set"
   729   HFinite        :: ('a::real_normed_vector) star set"
   730   HInfinite      :: ('a::real_normed_vector) star set"
   731   approx         :: ('a::real_normed_vector) star => 'a star => bool
   732   monad          :: ('a::real_normed_vector) star => 'a star set
   733   galaxy         :: ('a::real_normed_vector) star => 'a star set
   734   (NS)LIMSEQ     :: [nat, 'a::real_normed_vector, 'a] => bool
   735   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
   736   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
   737   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
   738   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
   739   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
   740   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
   741 
   742 * Complex: Some complex-specific constants are now abbreviations for
   743 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
   744 hnorm.  Other constants have been entirely removed in favor of the
   745 polymorphic versions (INCOMPATIBILITY):
   746 
   747   approx        <-- capprox
   748   HFinite       <-- CFinite
   749   HInfinite     <-- CInfinite
   750   Infinitesimal <-- CInfinitesimal
   751   monad         <-- cmonad
   752   galaxy        <-- cgalaxy
   753   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
   754   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
   755   (ns)deriv     <-- (ns)cderiv
   756 
   757 
   758 *** ML ***
   759 
   760 * ML within Isar: antiquotations allow to embed statically-checked
   761 formal entities in the source, referring to the context available at
   762 compile-time.  For example:
   763 
   764 ML {* @{typ "'a => 'b"} *}
   765 ML {* @{term "%x. x"} *}
   766 ML {* @{prop "x == y"} *}
   767 ML {* @{ctyp "'a => 'b"} *}
   768 ML {* @{cterm "%x. x"} *}
   769 ML {* @{cprop "x == y"} *}
   770 ML {* @{thm asm_rl} *}
   771 ML {* @{thms asm_rl} *}
   772 ML {* @{const_name c} *}
   773 ML {* @{const_syntax c} *}
   774 ML {* @{context} *}
   775 ML {* @{theory} *}
   776 ML {* @{theory Pure} *}
   777 ML {* @{simpset} *}
   778 ML {* @{claset} *}
   779 ML {* @{clasimpset} *}
   780 
   781 The same works for sources being ``used'' within an Isar context.
   782 
   783 * ML in Isar: improved error reporting; extra verbosity with
   784 Toplevel.debug enabled.
   785 
   786 * Pure/library:
   787 
   788   val burrow: ('a list -> 'b list) -> 'a list list -> 'b list list
   789   val fold_burrow: ('a list -> 'c -> 'b list * 'd) -> 'a list list -> 'c -> 'b list list * 'd
   790 
   791 The semantics of "burrow" is: "take a function with *simulatanously*
   792 transforms a list of value, and apply it *simulatanously* to a list of
   793 list of values of the appropriate type". Compare this with "map" which
   794 would *not* apply its argument function simulatanously but in
   795 sequence; "fold_burrow" has an additional context.
   796 
   797 * Pure/library: functions map2 and fold2 with curried syntax for
   798 simultanous mapping and folding:
   799 
   800     val map2: ('a -> 'b -> 'c) -> 'a list -> 'b list -> 'c list
   801     val fold2: ('a -> 'b -> 'c -> 'c) -> 'a list -> 'b list -> 'c -> 'c
   802 
   803 * Pure/library: indexed lists - some functions in the Isabelle library
   804 treating lists over 'a as finite mappings from [0...n] to 'a have been
   805 given more convenient names and signatures reminiscent of similar
   806 functions for alists, tables, etc:
   807 
   808   val nth: 'a list -> int -> 'a 
   809   val nth_map: int -> ('a -> 'a) -> 'a list -> 'a list
   810   val fold_index: (int * 'a -> 'b -> 'b) -> 'a list -> 'b -> 'b
   811 
   812 Note that fold_index starts counting at index 0, not 1 like foldln
   813 used to.
   814 
   815 * Pure/library: added general ``divide_and_conquer'' combinator on
   816 lists.
   817 
   818 * Pure/General/table.ML: the join operations now works via exceptions
   819 DUP/SAME instead of type option.  This is simpler in simple cases, and
   820 admits slightly more efficient complex applications.
   821 
   822 * Pure: datatype Context.generic joins theory/Proof.context and
   823 provides some facilities for code that works in either kind of
   824 context, notably GenericDataFun for uniform theory and proof data.
   825 
   826 * Pure: 'advanced' translation functions (parse_translation etc.) now
   827 use Context.generic instead of just theory.
   828 
   829 * Pure: simplified internal attribute type, which is now always
   830 Context.generic * thm -> Context.generic * thm.  Global (theory)
   831 vs. local (Proof.context) attributes have been discontinued, while
   832 minimizing code duplication.  Thm.rule_attribute and
   833 Thm.declaration_attribute build canonical attributes; see also
   834 structure Context for further operations on Context.generic, notably
   835 GenericDataFun.  INCOMPATIBILITY, need to adapt attribute type
   836 declarations and definitions.
   837 
   838 * Pure/kernel: consts certification ignores sort constraints given in
   839 signature declarations.  (This information is not relevant to the
   840 logic, but only for type inference.)  IMPORTANT INTERNAL CHANGE,
   841 potential INCOMPATIBILITY.
   842 
   843 * Pure: axiomatic type classes are now purely definitional, with
   844 explicit proofs of class axioms and super class relations performed
   845 internally.  See Pure/axclass.ML for the main internal interfaces --
   846 notably AxClass.define_class supercedes AxClass.add_axclass, and
   847 AxClass.axiomatize_class/classrel/arity supercede
   848 Sign.add_classes/classrel/arities.
   849 
   850 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
   851 global/local versions on theory vs. Proof.context have been
   852 discontinued; Attrib.syntax and Method.syntax have been adapted
   853 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
   854 attributes, methods, etc.
   855 
   856 * Pure: several functions of signature "... -> theory -> theory * ..."
   857 have been reoriented to "... -> theory -> ... * theory" in order to
   858 allow natural usage in combination with the ||>, ||>>, |-> and
   859 fold_map combinators.
   860 
   861 * Pure: official theorem names (closed derivations) and additional
   862 comments (tags) are now strictly separate.  Name hints -- which are
   863 maintained as tags -- may be attached any time without affecting the
   864 derivation.
   865 
   866 * Pure: primitive rule lift_rule now takes goal cterm instead of an
   867 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
   868 achieve the old behaviour.
   869 
   870 * Pure: the "Goal" constant is now called "prop", supporting a
   871 slightly more general idea of ``protecting'' meta-level rule
   872 statements.
   873 
   874 * Pure: Logic.(un)varify only works in a global context, which is now
   875 enforced instead of silently assumed.  INCOMPATIBILITY, may use
   876 Logic.legacy_(un)varify as temporary workaround.
   877 
   878 * Pure: structure Name provides scalable operations for generating
   879 internal variable names, notably Name.variants etc.  This replaces
   880 some popular functions from term.ML:
   881 
   882   Term.variant		->  Name.variant
   883   Term.variantlist	->  Name.variant_list  (*canonical argument order*)
   884   Term.invent_names	->  Name.invent_list
   885 
   886 Note that low-level renaming rarely occurs in new code -- operations
   887 from structure Variable are used instead (see below).
   888 
   889 * Pure: structure Variable provides fundamental operations for proper
   890 treatment of fixed/schematic variables in a context.  For example,
   891 Variable.import introduces fixes for schematics of given facts and
   892 Variable.export reverses the effect (up to renaming) -- this replaces
   893 various freeze_thaw operations.
   894 
   895 * Pure: structure Goal provides simple interfaces for
   896 init/conclude/finish and tactical prove operations (replacing former
   897 Tactic.prove).  Goal.prove is the canonical way to prove results
   898 within a given context; Goal.prove_global is a degraded version for
   899 theory level goals, including a global Drule.standard.  Note that
   900 OldGoals.prove_goalw_cterm has long been obsolete, since it is
   901 ill-behaved in a local proof context (e.g. with local fixes/assumes or
   902 in a locale context).
   903 
   904 * Isar: simplified treatment of user-level errors, using exception
   905 ERROR of string uniformly.  Function error now merely raises ERROR,
   906 without any side effect on output channels.  The Isar toplevel takes
   907 care of proper display of ERROR exceptions.  ML code may use plain
   908 handle/can/try; cat_error may be used to concatenate errors like this:
   909 
   910   ... handle ERROR msg => cat_error msg "..."
   911 
   912 Toplevel ML code (run directly or through the Isar toplevel) may be
   913 embedded into the Isar toplevel with exception display/debug like
   914 this:
   915 
   916   Isar.toplevel (fn () => ...)
   917 
   918 INCOMPATIBILITY, removed special transform_error facilities, removed
   919 obsolete variants of user-level exceptions (ERROR_MESSAGE,
   920 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
   921 -- use plain ERROR instead.
   922 
   923 * Isar: theory setup now has type (theory -> theory), instead of a
   924 list.  INCOMPATIBILITY, may use #> to compose setup functions.
   925 
   926 * Isar: installed ML toplevel pretty printer for type Proof.context,
   927 subject to ProofContext.debug/verbose flags.
   928 
   929 * Isar: Toplevel.theory_to_proof admits transactions that modify the
   930 theory before entering a proof state.  Transactions now always see a
   931 quasi-functional intermediate checkpoint, both in interactive and
   932 batch mode.
   933 
   934 * Simplifier: the simpset of a running simplification process now
   935 contains a proof context (cf. Simplifier.the_context), which is the
   936 very context that the initial simpset has been retrieved from (by
   937 simpset_of/local_simpset_of).  Consequently, all plug-in components
   938 (solver, looper etc.) may depend on arbitrary proof data.
   939 
   940 * Simplifier.inherit_context inherits the proof context (plus the
   941 local bounds) of the current simplification process; any simproc
   942 etc. that calls the Simplifier recursively should do this!  Removed
   943 former Simplifier.inherit_bounds, which is already included here --
   944 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
   945 specify an explicit context using Simplifier.context/theory_context.
   946 
   947 * Simplifier/Classical Reasoner: more abstract interfaces
   948 change_simpset/claset for modifying the simpset/claset reference of a
   949 theory; raw versions simpset/claset_ref etc. have been discontinued --
   950 INCOMPATIBILITY.
   951 
   952 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
   953 "Trueprop" etc.
   954 
   955 
   956 *** System ***
   957 
   958 * settings: ML_IDENTIFIER -- which is appended to user specific heap
   959 locations -- now includes the Isabelle version identifier as well.
   960 This simplifies use of multiple Isabelle installations.
   961 
   962 * isabelle-process: option -S (secure mode) disables some critical
   963 operations, notably runtime compilation and evaluation of ML source
   964 code.
   965 
   966 
   967 New in Isabelle2005 (October 2005)
   968 ----------------------------------
   969 
   970 *** General ***
   971 
   972 * Theory headers: the new header syntax for Isar theories is
   973 
   974   theory <name>
   975   imports <theory1> ... <theoryN>
   976   uses <file1> ... <fileM>
   977   begin
   978 
   979 where the 'uses' part is optional.  The previous syntax
   980 
   981   theory <name> = <theory1> + ... + <theoryN>:
   982 
   983 will disappear in the next release.  Use isatool fixheaders to convert
   984 existing theory files.  Note that there is no change in ancient
   985 non-Isar theories now, but these will disappear soon.
   986 
   987 * Theory loader: parent theories can now also be referred to via
   988 relative and absolute paths.
   989 
   990 * Command 'find_theorems' searches for a list of criteria instead of a
   991 list of constants. Known criteria are: intro, elim, dest, name:string,
   992 simp:term, and any term. Criteria can be preceded by '-' to select
   993 theorems that do not match. Intro, elim, dest select theorems that
   994 match the current goal, name:s selects theorems whose fully qualified
   995 name contain s, and simp:term selects all simplification rules whose
   996 lhs match term.  Any other term is interpreted as pattern and selects
   997 all theorems matching the pattern. Available in ProofGeneral under
   998 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
   999 
  1000   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  1001 
  1002 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  1003 matching the current goal as introduction rule and not having "HOL."
  1004 in their name (i.e. not being defined in theory HOL).
  1005 
  1006 * Command 'thms_containing' has been discontinued in favour of
  1007 'find_theorems'; INCOMPATIBILITY.
  1008 
  1009 * Communication with Proof General is now 8bit clean, which means that
  1010 Unicode text in UTF-8 encoding may be used within theory texts (both
  1011 formal and informal parts).  Cf. option -U of the Isabelle Proof
  1012 General interface.  Here are some simple examples (cf. src/HOL/ex):
  1013 
  1014   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  1015   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  1016 
  1017 * Improved efficiency of the Simplifier and, to a lesser degree, the
  1018 Classical Reasoner.  Typical big applications run around 2 times
  1019 faster.
  1020 
  1021 
  1022 *** Document preparation ***
  1023 
  1024 * Commands 'display_drafts' and 'print_drafts' perform simple output
  1025 of raw sources.  Only those symbols that do not require additional
  1026 LaTeX packages (depending on comments in isabellesym.sty) are
  1027 displayed properly, everything else is left verbatim.  isatool display
  1028 and isatool print are used as front ends (these are subject to the
  1029 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  1030 
  1031 * Command tags control specific markup of certain regions of text,
  1032 notably folding and hiding.  Predefined tags include "theory" (for
  1033 theory begin and end), "proof" for proof commands, and "ML" for
  1034 commands involving ML code; the additional tags "visible" and
  1035 "invisible" are unused by default.  Users may give explicit tag
  1036 specifications in the text, e.g. ''by %invisible (auto)''.  The
  1037 interpretation of tags is determined by the LaTeX job during document
  1038 preparation: see option -V of isatool usedir, or options -n and -t of
  1039 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  1040 \isadroptag.
  1041 
  1042 Several document versions may be produced at the same time via isatool
  1043 usedir (the generated index.html will link all of them).  Typical
  1044 specifications include ''-V document=theory,proof,ML'' to present
  1045 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  1046 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  1047 these parts without any formal replacement text.  The Isabelle site
  1048 default settings produce ''document'' and ''outline'' versions as
  1049 specified above.
  1050 
  1051 * Several new antiquotations:
  1052 
  1053   @{term_type term} prints a term with its type annotated;
  1054 
  1055   @{typeof term} prints the type of a term;
  1056 
  1057   @{const const} is the same as @{term const}, but checks that the
  1058   argument is a known logical constant;
  1059 
  1060   @{term_style style term} and @{thm_style style thm} print a term or
  1061   theorem applying a "style" to it
  1062 
  1063   @{ML text}
  1064 
  1065 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  1066 definitions, equations, inequations etc., 'concl' printing only the
  1067 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  1068 to print the specified premise.  TermStyle.add_style provides an ML
  1069 interface for introducing further styles.  See also the "LaTeX Sugar"
  1070 document practical applications.  The ML antiquotation prints
  1071 type-checked ML expressions verbatim.
  1072 
  1073 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  1074 and 'text' support optional locale specification '(in loc)', which
  1075 specifies the default context for interpreting antiquotations.  For
  1076 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  1077 
  1078 * Option 'locale=NAME' of antiquotations specifies an alternative
  1079 context interpreting the subsequent argument.  For example: @{thm
  1080 [locale=lattice] inf_assoc}.
  1081 
  1082 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  1083 a proof context.
  1084 
  1085 * Proper output of antiquotations for theory commands involving a
  1086 proof context (such as 'locale' or 'theorem (in loc) ...').
  1087 
  1088 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  1089 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  1090 
  1091 * isatool usedir: new option -C (default true) controls whether option
  1092 -D should include a copy of the original document directory; -C false
  1093 prevents unwanted effects such as copying of administrative CVS data.
  1094 
  1095 
  1096 *** Pure ***
  1097 
  1098 * Considerably improved version of 'constdefs' command.  Now performs
  1099 automatic type-inference of declared constants; additional support for
  1100 local structure declarations (cf. locales and HOL records), see also
  1101 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  1102 sequential dependencies of definitions within a single 'constdefs'
  1103 section; moreover, the declared name needs to be an identifier.  If
  1104 all fails, consider to fall back on 'consts' and 'defs' separately.
  1105 
  1106 * Improved indexed syntax and implicit structures.  First of all,
  1107 indexed syntax provides a notational device for subscripted
  1108 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  1109 expressions.  Secondly, in a local context with structure
  1110 declarations, number indexes \<^sub>n or the empty index (default
  1111 number 1) refer to a certain fixed variable implicitly; option
  1112 show_structs controls printing of implicit structures.  Typical
  1113 applications of these concepts involve record types and locales.
  1114 
  1115 * New command 'no_syntax' removes grammar declarations (and
  1116 translations) resulting from the given syntax specification, which is
  1117 interpreted in the same manner as for the 'syntax' command.
  1118 
  1119 * 'Advanced' translation functions (parse_translation etc.) may depend
  1120 on the signature of the theory context being presently used for
  1121 parsing/printing, see also isar-ref manual.
  1122 
  1123 * Improved 'oracle' command provides a type-safe interface to turn an
  1124 ML expression of type theory -> T -> term into a primitive rule of
  1125 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  1126 is already included here); see also FOL/ex/IffExample.thy;
  1127 INCOMPATIBILITY.
  1128 
  1129 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  1130 before); "cI" is no longer bound, use "c.intro" instead.
  1131 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  1132 axclasses vs. locales.
  1133 
  1134 * Improved internal renaming of symbolic identifiers -- attach primes
  1135 instead of base 26 numbers.
  1136 
  1137 * New flag show_question_marks controls printing of leading question
  1138 marks in schematic variable names.
  1139 
  1140 * In schematic variable names, *any* symbol following \<^isub> or
  1141 \<^isup> is now treated as part of the base name.  For example, the
  1142 following works without printing of awkward ".0" indexes:
  1143 
  1144   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  1145     by simp
  1146 
  1147 * Inner syntax includes (*(*nested*) comments*).
  1148 
  1149 * Pretty printer now supports unbreakable blocks, specified in mixfix
  1150 annotations as "(00...)".
  1151 
  1152 * Clear separation of logical types and nonterminals, where the latter
  1153 may only occur in 'syntax' specifications or type abbreviations.
  1154 Before that distinction was only partially implemented via type class
  1155 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  1156 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  1157 exotic syntax specifications may require further adaption
  1158 (e.g. Cube/Cube.thy).
  1159 
  1160 * Removed obsolete type class "logic", use the top sort {} instead.
  1161 Note that non-logical types should be declared as 'nonterminals'
  1162 rather than 'types'.  INCOMPATIBILITY for new object-logic
  1163 specifications.
  1164 
  1165 * Attributes 'induct' and 'cases': type or set names may now be
  1166 locally fixed variables as well.
  1167 
  1168 * Simplifier: can now control the depth to which conditional rewriting
  1169 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  1170 Limit.
  1171 
  1172 * Simplifier: simplification procedures may now take the current
  1173 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  1174 interface), which is very useful for calling the Simplifier
  1175 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  1176 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  1177 low-level mk_simproc no longer applies Logic.varify internally, to
  1178 allow for use in a context of fixed variables.
  1179 
  1180 * thin_tac now works even if the assumption being deleted contains !!
  1181 or ==>.  More generally, erule now works even if the major premise of
  1182 the elimination rule contains !! or ==>.
  1183 
  1184 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  1185 
  1186 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  1187 from Pure, which contains all common declarations already.  Both
  1188 theories are defined via plain Isabelle/Isar .thy files.
  1189 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  1190 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  1191 use isatool fixcpure to adapt your theory and ML sources.
  1192 
  1193 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  1194 selections of theorems in named facts via index ranges.
  1195 
  1196 * 'print_theorems': in theory mode, really print the difference
  1197 wrt. the last state (works for interactive theory development only),
  1198 in proof mode print all local facts (cf. 'print_facts');
  1199 
  1200 * 'hide': option '(open)' hides only base names.
  1201 
  1202 * More efficient treatment of intermediate checkpoints in interactive
  1203 theory development.
  1204 
  1205 * Code generator is now invoked via code_module (incremental code
  1206 generation) and code_library (modular code generation, ML structures
  1207 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  1208 must be quoted when used as identifiers.
  1209 
  1210 * New 'value' command for reading, evaluating and printing terms using
  1211 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  1212 quoted when used as identifier.
  1213 
  1214 
  1215 *** Locales ***
  1216 
  1217 * New commands for the interpretation of locale expressions in
  1218 theories (1), locales (2) and proof contexts (3).  These generate
  1219 proof obligations from the expression specification.  After the
  1220 obligations have been discharged, theorems of the expression are added
  1221 to the theory, target locale or proof context.  The synopsis of the
  1222 commands is a follows:
  1223 
  1224   (1) interpretation expr inst
  1225   (2) interpretation target < expr
  1226   (3) interpret expr inst
  1227 
  1228 Interpretation in theories and proof contexts require a parameter
  1229 instantiation of terms from the current context.  This is applied to
  1230 specifications and theorems of the interpreted expression.
  1231 Interpretation in locales only permits parameter renaming through the
  1232 locale expression.  Interpretation is smart in that interpretations
  1233 that are active already do not occur in proof obligations, neither are
  1234 instantiated theorems stored in duplicate.  Use 'print_interps' to
  1235 inspect active interpretations of a particular locale.  For details,
  1236 see the Isar Reference manual.  Examples can be found in
  1237 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  1238 
  1239 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  1240 'interpret' instead.
  1241 
  1242 * New context element 'constrains' for adding type constraints to
  1243 parameters.
  1244 
  1245 * Context expressions: renaming of parameters with syntax
  1246 redeclaration.
  1247 
  1248 * Locale declaration: 'includes' disallowed.
  1249 
  1250 * Proper static binding of attribute syntax -- i.e. types / terms /
  1251 facts mentioned as arguments are always those of the locale definition
  1252 context, independently of the context of later invocations.  Moreover,
  1253 locale operations (renaming and type / term instantiation) are applied
  1254 to attribute arguments as expected.
  1255 
  1256 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  1257 actual attributes; rare situations may require Attrib.attribute to
  1258 embed those attributes into Attrib.src that lack concrete syntax.
  1259 Attribute implementations need to cooperate properly with the static
  1260 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  1261 Attrib.XXX_thm etc. already do the right thing without further
  1262 intervention.  Only unusual applications -- such as "where" or "of"
  1263 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  1264 on the context and the facts involved -- may have to assign parsed
  1265 values to argument tokens explicitly.
  1266 
  1267 * Changed parameter management in theorem generation for long goal
  1268 statements with 'includes'.  INCOMPATIBILITY: produces a different
  1269 theorem statement in rare situations.
  1270 
  1271 * Locale inspection command 'print_locale' omits notes elements.  Use
  1272 'print_locale!' to have them included in the output.
  1273 
  1274 
  1275 *** Provers ***
  1276 
  1277 * Provers/hypsubst.ML: improved version of the subst method, for
  1278 single-step rewriting: it now works in bound variable contexts. New is
  1279 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  1280 rewrite a different subterm than the original subst method, which is
  1281 still available as 'simplesubst'.
  1282 
  1283 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  1284 and quasi orders.
  1285 
  1286 * Provers/trancl.ML: new transitivity reasoner for transitive and
  1287 reflexive-transitive closure of relations.
  1288 
  1289 * Provers/blast.ML: new reference depth_limit to make blast's depth
  1290 limit (previously hard-coded with a value of 20) user-definable.
  1291 
  1292 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  1293 is peformed already.  Object-logics merely need to finish their
  1294 initial simpset configuration as before.  INCOMPATIBILITY.
  1295 
  1296 
  1297 *** HOL ***
  1298 
  1299 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  1300 
  1301   syntax (epsilon)
  1302     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  1303 
  1304 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  1305 and x-symbol; use option '-m epsilon' to get it actually printed.
  1306 Moreover, the mathematically important symbolic identifier \<epsilon>
  1307 becomes available as variable, constant etc.  INCOMPATIBILITY,
  1308 
  1309 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  1310 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  1311 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  1312 support corresponding Isar calculations.
  1313 
  1314 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  1315 instead of ":".
  1316 
  1317 * theory SetInterval: changed the syntax for open intervals:
  1318 
  1319   Old       New
  1320   {..n(}    {..<n}
  1321   {)n..}    {n<..}
  1322   {m..n(}   {m..<n}
  1323   {)m..n}   {m<..n}
  1324   {)m..n(}  {m<..<n}
  1325 
  1326 The old syntax is still supported but will disappear in the next
  1327 release.  For conversion use the following Emacs search and replace
  1328 patterns (these are not perfect but work quite well):
  1329 
  1330   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  1331   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  1332 
  1333 * Theory Commutative_Ring (in Library): method comm_ring for proving
  1334 equalities in commutative rings; method 'algebra' provides a generic
  1335 interface.
  1336 
  1337 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  1338 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  1339 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  1340 be a tuple pattern.
  1341 
  1342 Some new syntax forms are available:
  1343 
  1344   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  1345   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  1346   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  1347   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  1348 
  1349 The latter form "\<Sum>x < k. e" used to be based on a separate
  1350 function "Summation", which has been discontinued.
  1351 
  1352 * theory Finite_Set: in structured induction proofs, the insert case
  1353 is now 'case (insert x F)' instead of the old counterintuitive 'case
  1354 (insert F x)'.
  1355 
  1356 * The 'refute' command has been extended to support a much larger
  1357 fragment of HOL, including axiomatic type classes, constdefs and
  1358 typedefs, inductive datatypes and recursion.
  1359 
  1360 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  1361 Requires zChaff with proof generation to be installed.  See
  1362 HOL/ex/SAT_Examples.thy for examples.
  1363 
  1364 * Datatype induction via method 'induct' now preserves the name of the
  1365 induction variable. For example, when proving P(xs::'a list) by
  1366 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  1367 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  1368 in unstructured proof scripts.
  1369 
  1370 * Reworked implementation of records.  Improved scalability for
  1371 records with many fields, avoiding performance problems for type
  1372 inference. Records are no longer composed of nested field types, but
  1373 of nested extension types. Therefore the record type only grows linear
  1374 in the number of extensions and not in the number of fields.  The
  1375 top-level (users) view on records is preserved.  Potential
  1376 INCOMPATIBILITY only in strange cases, where the theory depends on the
  1377 old record representation. The type generated for a record is called
  1378 <record_name>_ext_type.
  1379 
  1380 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  1381 proofs triggered by a record definition or a simproc (if
  1382 quick_and_dirty is enabled).  Definitions of large records can take
  1383 quite long.
  1384 
  1385 New simproc record_upd_simproc for simplification of multiple record
  1386 updates enabled by default.  Moreover, trivial updates are also
  1387 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  1388 occasionally, since simplification is more powerful by default.
  1389 
  1390 * typedef: proper support for polymorphic sets, which contain extra
  1391 type-variables in the term.
  1392 
  1393 * Simplifier: automatically reasons about transitivity chains
  1394 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  1395 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  1396 old proofs break occasionally as simplification may now solve more
  1397 goals than previously.
  1398 
  1399 * Simplifier: converts x <= y into x = y if assumption y <= x is
  1400 present.  Works for all partial orders (class "order"), in particular
  1401 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  1402 just like y <= x.
  1403 
  1404 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  1405 bound variable or a constant then the let is unfolded.  Otherwise
  1406 first a is simplified to b, and then f b is simplified to g. If
  1407 possible we abstract b from g arriving at "let x = b in h x",
  1408 otherwise we unfold the let and arrive at g.  The simproc can be
  1409 enabled/disabled by the reference use_let_simproc.  Potential
  1410 INCOMPATIBILITY since simplification is more powerful by default.
  1411 
  1412 * Classical reasoning: the meson method now accepts theorems as arguments.
  1413 
  1414 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  1415 jobs to provide advice on the provability of subgoals.
  1416 
  1417 * Theory OrderedGroup and Ring_and_Field: various additions and
  1418 improvements to faciliate calculations involving equalities and
  1419 inequalities.
  1420 
  1421 The following theorems have been eliminated or modified
  1422 (INCOMPATIBILITY):
  1423 
  1424   abs_eq             now named abs_of_nonneg
  1425   abs_of_ge_0        now named abs_of_nonneg
  1426   abs_minus_eq       now named abs_of_nonpos
  1427   imp_abs_id         now named abs_of_nonneg
  1428   imp_abs_neg_id     now named abs_of_nonpos
  1429   mult_pos           now named mult_pos_pos
  1430   mult_pos_le        now named mult_nonneg_nonneg
  1431   mult_pos_neg_le    now named mult_nonneg_nonpos
  1432   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  1433   mult_neg           now named mult_neg_neg
  1434   mult_neg_le        now named mult_nonpos_nonpos
  1435 
  1436 * Theory Parity: added rules for simplifying exponents.
  1437 
  1438 * Theory List:
  1439 
  1440 The following theorems have been eliminated or modified
  1441 (INCOMPATIBILITY):
  1442 
  1443   list_all_Nil       now named list_all.simps(1)
  1444   list_all_Cons      now named list_all.simps(2)
  1445   list_all_conv      now named list_all_iff
  1446   set_mem_eq         now named mem_iff
  1447 
  1448 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  1449 asymptotic "big O" calculations.  See the notes in BigO.thy.
  1450 
  1451 
  1452 *** HOL-Complex ***
  1453 
  1454 * Theory RealDef: better support for embedding natural numbers and
  1455 integers in the reals.
  1456 
  1457 The following theorems have been eliminated or modified
  1458 (INCOMPATIBILITY):
  1459 
  1460   exp_ge_add_one_self  now requires no hypotheses
  1461   real_of_int_add      reversed direction of equality (use [symmetric])
  1462   real_of_int_minus    reversed direction of equality (use [symmetric])
  1463   real_of_int_diff     reversed direction of equality (use [symmetric])
  1464   real_of_int_mult     reversed direction of equality (use [symmetric])
  1465 
  1466 * Theory RComplete: expanded support for floor and ceiling functions.
  1467 
  1468 * Theory Ln is new, with properties of the natural logarithm
  1469 
  1470 * Hyperreal: There is a new type constructor "star" for making
  1471 nonstandard types.  The old type names are now type synonyms:
  1472 
  1473   hypreal = real star
  1474   hypnat = nat star
  1475   hcomplex = complex star
  1476 
  1477 * Hyperreal: Many groups of similarly-defined constants have been
  1478 replaced by polymorphic versions (INCOMPATIBILITY):
  1479 
  1480   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  1481 
  1482   starset      <-- starsetNat, starsetC
  1483   *s*          <-- *sNat*, *sc*
  1484   starset_n    <-- starsetNat_n, starsetC_n
  1485   *sn*         <-- *sNatn*, *scn*
  1486   InternalSets <-- InternalNatSets, InternalCSets
  1487 
  1488   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  1489   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  1490   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  1491   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  1492   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  1493 
  1494 * Hyperreal: Many type-specific theorems have been removed in favor of
  1495 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  1496 
  1497   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  1498   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  1499   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  1500   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  1501   right_minus <-- hypreal_add_minus
  1502   left_minus <-- {hypreal,hcomplex}_add_minus_left
  1503   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  1504   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  1505   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  1506   mult_1_right <-- hcomplex_mult_one_right
  1507   mult_zero_left <-- hcomplex_mult_zero_left
  1508   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  1509   right_distrib <-- hypnat_add_mult_distrib2
  1510   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  1511   right_inverse <-- hypreal_mult_inverse
  1512   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  1513   order_refl <-- {hypreal,hypnat}_le_refl
  1514   order_trans <-- {hypreal,hypnat}_le_trans
  1515   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  1516   order_less_le <-- {hypreal,hypnat}_less_le
  1517   linorder_linear <-- {hypreal,hypnat}_le_linear
  1518   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  1519   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  1520   add_nonneg_nonneg <-- hypreal_le_add_order
  1521 
  1522 * Hyperreal: Separate theorems having to do with type-specific
  1523 versions of constants have been merged into theorems that apply to the
  1524 new polymorphic constants (INCOMPATIBILITY):
  1525 
  1526   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  1527   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  1528   STAR_Un <-- {STAR,NatStar,STARC}_Un
  1529   STAR_Int <-- {STAR,NatStar,STARC}_Int
  1530   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  1531   STAR_subset <-- {STAR,NatStar,STARC}_subset
  1532   STAR_mem <-- {STAR,NatStar,STARC}_mem
  1533   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  1534   STAR_diff <-- {STAR,STARC}_diff
  1535   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  1536     STARC_hcomplex_of_complex}_image_subset
  1537   starset_n_Un <-- starset{Nat,C}_n_Un
  1538   starset_n_Int <-- starset{Nat,C}_n_Int
  1539   starset_n_Compl <-- starset{Nat,C}_n_Compl
  1540   starset_n_diff <-- starset{Nat,C}_n_diff
  1541   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  1542   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  1543   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  1544   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  1545   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  1546   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  1547   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  1548   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  1549   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  1550   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  1551   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  1552   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  1553   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  1554   starfun_diff <-- starfun{C,RC,CR}_diff
  1555   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  1556   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  1557   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  1558   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  1559   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  1560   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  1561   starfun_Id <-- starfunC_Id
  1562   starfun_approx <-- starfun{Nat,CR}_approx
  1563   starfun_capprox <-- starfun{C,RC}_capprox
  1564   starfun_abs <-- starfunNat_rabs
  1565   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  1566   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  1567   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  1568   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  1569   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  1570   starfun_add_approx <-- starfunCR_add_approx
  1571   starfun_inverse_inverse <-- starfunC_inverse_inverse
  1572   starfun_divide <-- starfun{C,CR,RC}_divide
  1573   starfun_n <-- starfun{Nat,C}_n
  1574   starfun_n_mult <-- starfun{Nat,C}_n_mult
  1575   starfun_n_add <-- starfun{Nat,C}_n_add
  1576   starfun_n_add_minus <-- starfunNat_n_add_minus
  1577   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  1578   starfun_n_minus <-- starfun{Nat,C}_n_minus
  1579   starfun_n_eq <-- starfun{Nat,C}_n_eq
  1580 
  1581   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  1582   star_n_minus <-- {hypreal,hcomplex}_minus
  1583   star_n_diff <-- {hypreal,hcomplex}_diff
  1584   star_n_mult <-- {hypreal,hcomplex}_mult
  1585   star_n_inverse <-- {hypreal,hcomplex}_inverse
  1586   star_n_le <-- {hypreal,hypnat}_le
  1587   star_n_less <-- {hypreal,hypnat}_less
  1588   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  1589   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  1590   star_n_abs <-- hypreal_hrabs
  1591   star_n_divide <-- hcomplex_divide
  1592 
  1593   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  1594   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  1595   star_of_diff <-- hypreal_of_real_diff
  1596   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  1597   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  1598   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  1599   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  1600   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  1601   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  1602   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  1603   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  1604   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  1605   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  1606   star_of_number_of <-- {hypreal,hcomplex}_number_of
  1607   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  1608   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  1609   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  1610   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  1611   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  1612   star_of_power <-- hypreal_of_real_power
  1613   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  1614 
  1615 * Hyperreal: new method "transfer" that implements the transfer
  1616 principle of nonstandard analysis. With a subgoal that mentions
  1617 nonstandard types like "'a star", the command "apply transfer"
  1618 replaces it with an equivalent one that mentions only standard types.
  1619 To be successful, all free variables must have standard types; non-
  1620 standard variables must have explicit universal quantifiers.
  1621 
  1622 * Hyperreal: A theory of Taylor series.
  1623 
  1624 
  1625 *** HOLCF ***
  1626 
  1627 * Discontinued special version of 'constdefs' (which used to support
  1628 continuous functions) in favor of the general Pure one with full
  1629 type-inference.
  1630 
  1631 * New simplification procedure for solving continuity conditions; it
  1632 is much faster on terms with many nested lambda abstractions (cubic
  1633 instead of exponential time).
  1634 
  1635 * New syntax for domain package: selector names are now optional.
  1636 Parentheses should be omitted unless argument is lazy, for example:
  1637 
  1638   domain 'a stream = cons "'a" (lazy "'a stream")
  1639 
  1640 * New command 'fixrec' for defining recursive functions with pattern
  1641 matching; defining multiple functions with mutual recursion is also
  1642 supported.  Patterns may include the constants cpair, spair, up, sinl,
  1643 sinr, or any data constructor defined by the domain package. The given
  1644 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  1645 syntax and examples.
  1646 
  1647 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  1648 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  1649 but the proof obligation additionally includes an admissibility
  1650 requirement. The packages generate instances of class cpo or pcpo,
  1651 with continuity and strictness theorems for Rep and Abs.
  1652 
  1653 * HOLCF: Many theorems have been renamed according to a more standard naming
  1654 scheme (INCOMPATIBILITY):
  1655 
  1656   foo_inject:  "foo$x = foo$y ==> x = y"
  1657   foo_eq:      "(foo$x = foo$y) = (x = y)"
  1658   foo_less:    "(foo$x << foo$y) = (x << y)"
  1659   foo_strict:  "foo$UU = UU"
  1660   foo_defined: "... ==> foo$x ~= UU"
  1661   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  1662 
  1663 
  1664 *** ZF ***
  1665 
  1666 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  1667 including the First Isomorphism Theorem (on quotienting by the kernel
  1668 of a homomorphism).
  1669 
  1670 * ZF/Simplifier: install second copy of type solver that actually
  1671 makes use of TC rules declared to Isar proof contexts (or locales);
  1672 the old version is still required for ML proof scripts.
  1673 
  1674 
  1675 *** Cube ***
  1676 
  1677 * Converted to Isar theory format; use locales instead of axiomatic
  1678 theories.
  1679 
  1680 
  1681 *** ML ***
  1682 
  1683 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  1684 for ||>, ||>>, |>>,
  1685 
  1686 * Pure/library.ML no longer defines its own option datatype, but uses
  1687 that of the SML basis, which has constructors NONE and SOME instead of
  1688 None and Some, as well as exception Option.Option instead of OPTION.
  1689 The functions the, if_none, is_some, is_none have been adapted
  1690 accordingly, while Option.map replaces apsome.
  1691 
  1692 * Pure/library.ML: the exception LIST has been given up in favour of
  1693 the standard exceptions Empty and Subscript, as well as
  1694 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  1695 superceded by the standard hd and tl functions etc.
  1696 
  1697 A number of basic list functions are no longer exported to the ML
  1698 toplevel, as they are variants of predefined functions.  The following
  1699 suggests how one can translate existing code:
  1700 
  1701     rev_append xs ys = List.revAppend (xs, ys)
  1702     nth_elem (i, xs) = List.nth (xs, i)
  1703     last_elem xs = List.last xs
  1704     flat xss = List.concat xss
  1705     seq fs = List.app fs
  1706     partition P xs = List.partition P xs
  1707     mapfilter f xs = List.mapPartial f xs
  1708 
  1709 * Pure/library.ML: several combinators for linear functional
  1710 transformations, notably reverse application and composition:
  1711 
  1712   x |> f                f #> g
  1713   (x, y) |-> f          f #-> g
  1714 
  1715 * Pure/library.ML: introduced/changed precedence of infix operators:
  1716 
  1717   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  1718   infix 2 ?;
  1719   infix 3 o oo ooo oooo;
  1720   infix 4 ~~ upto downto;
  1721 
  1722 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  1723 infix operators.
  1724 
  1725 * Pure/library.ML: natural list combinators fold, fold_rev, and
  1726 fold_map support linear functional transformations and nesting.  For
  1727 example:
  1728 
  1729   fold f [x1, ..., xN] y =
  1730     y |> f x1 |> ... |> f xN
  1731 
  1732   (fold o fold) f [xs1, ..., xsN] y =
  1733     y |> fold f xs1 |> ... |> fold f xsN
  1734 
  1735   fold f [x1, ..., xN] =
  1736     f x1 #> ... #> f xN
  1737 
  1738   (fold o fold) f [xs1, ..., xsN] =
  1739     fold f xs1 #> ... #> fold f xsN
  1740 
  1741 * Pure/library.ML: the following selectors on type 'a option are
  1742 available:
  1743 
  1744   the:               'a option -> 'a  (*partial*)
  1745   these:             'a option -> 'a  where 'a = 'b list
  1746   the_default: 'a -> 'a option -> 'a
  1747   the_list:          'a option -> 'a list
  1748 
  1749 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  1750 basic operations for association lists, following natural argument
  1751 order; moreover the explicit equality predicate passed here avoids
  1752 potentially expensive polymorphic runtime equality checks.
  1753 The old functions may be expressed as follows:
  1754 
  1755   assoc = uncurry (AList.lookup (op =))
  1756   assocs = these oo AList.lookup (op =)
  1757   overwrite = uncurry (AList.update (op =)) o swap
  1758 
  1759 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  1760 
  1761   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  1762   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  1763 
  1764 replacing make_keylist and keyfilter (occassionally used)
  1765 Naive rewrites:
  1766 
  1767   make_keylist = AList.make
  1768   keyfilter = AList.find (op =)
  1769 
  1770 * eq_fst and eq_snd now take explicit equality parameter, thus
  1771   avoiding eqtypes. Naive rewrites:
  1772 
  1773     eq_fst = eq_fst (op =)
  1774     eq_snd = eq_snd (op =)
  1775 
  1776 * Removed deprecated apl and apr (rarely used).
  1777   Naive rewrites:
  1778 
  1779     apl (n, op) =>>= curry op n
  1780     apr (op, m) =>>= fn n => op (n, m)
  1781 
  1782 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  1783 provides a reasonably efficient light-weight implementation of sets as
  1784 lists.
  1785 
  1786 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  1787 few new operations; existing lookup and update are now curried to
  1788 follow natural argument order (for use with fold etc.);
  1789 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  1790 
  1791 * Pure/General: output via the Isabelle channels of
  1792 writeln/warning/error etc. is now passed through Output.output, with a
  1793 hook for arbitrary transformations depending on the print_mode
  1794 (cf. Output.add_mode -- the first active mode that provides a output
  1795 function wins).  Already formatted output may be embedded into further
  1796 text via Output.raw; the result of Pretty.string_of/str_of and derived
  1797 functions (string_of_term/cterm/thm etc.) is already marked raw to
  1798 accommodate easy composition of diagnostic messages etc.  Programmers
  1799 rarely need to care about Output.output or Output.raw at all, with
  1800 some notable exceptions: Output.output is required when bypassing the
  1801 standard channels (writeln etc.), or in token translations to produce
  1802 properly formatted results; Output.raw is required when capturing
  1803 already output material that will eventually be presented to the user
  1804 a second time.  For the default print mode, both Output.output and
  1805 Output.raw have no effect.
  1806 
  1807 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  1808 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  1809 cumulative results are displayed at the end of a batch session.
  1810 
  1811 * Pure/General: File.sysify_path and File.quote_sysify path have been
  1812 replaced by File.platform_path and File.shell_path (with appropriate
  1813 hooks).  This provides a clean interface for unusual systems where the
  1814 internal and external process view of file names are different.
  1815 
  1816 * Pure: more efficient orders for basic syntactic entities: added
  1817 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  1818 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  1819 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  1820 orders now -- potential INCOMPATIBILITY for code that depends on a
  1821 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  1822 Library.sort_strings on result).
  1823 
  1824 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  1825 fold_types traverse types/terms from left to right, observing natural
  1826 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  1827 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  1828 
  1829 * Pure: name spaces have been refined, with significant changes of the
  1830 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  1831 to extern(_table).  The plain name entry path is superceded by a
  1832 general 'naming' context, which also includes the 'policy' to produce
  1833 a fully qualified name and external accesses of a fully qualified
  1834 name; NameSpace.extend is superceded by context dependent
  1835 Sign.declare_name.  Several theory and proof context operations modify
  1836 the naming context.  Especially note Theory.restore_naming and
  1837 ProofContext.restore_naming to get back to a sane state; note that
  1838 Theory.add_path is no longer sufficient to recover from
  1839 Theory.absolute_path in particular.
  1840 
  1841 * Pure: new flags short_names (default false) and unique_names
  1842 (default true) for controlling output of qualified names.  If
  1843 short_names is set, names are printed unqualified.  If unique_names is
  1844 reset, the name prefix is reduced to the minimum required to achieve
  1845 the original result when interning again, even if there is an overlap
  1846 with earlier declarations.
  1847 
  1848 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  1849 now 'extend', and 'merge' gets an additional Pretty.pp argument
  1850 (useful for printing error messages).  INCOMPATIBILITY.
  1851 
  1852 * Pure: major reorganization of the theory context.  Type Sign.sg and
  1853 Theory.theory are now identified, referring to the universal
  1854 Context.theory (see Pure/context.ML).  Actual signature and theory
  1855 content is managed as theory data.  The old code and interfaces were
  1856 spread over many files and structures; the new arrangement introduces
  1857 considerable INCOMPATIBILITY to gain more clarity:
  1858 
  1859   Context -- theory management operations (name, identity, inclusion,
  1860     parents, ancestors, merge, etc.), plus generic theory data;
  1861 
  1862   Sign -- logical signature and syntax operations (declaring consts,
  1863     types, etc.), plus certify/read for common entities;
  1864 
  1865   Theory -- logical theory operations (stating axioms, definitions,
  1866     oracles), plus a copy of logical signature operations (consts,
  1867     types, etc.); also a few basic management operations (Theory.copy,
  1868     Theory.merge, etc.)
  1869 
  1870 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  1871 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  1872 for convenience -- they merely return the theory.
  1873 
  1874 * Pure: type Type.tsig is superceded by theory in most interfaces.
  1875 
  1876 * Pure: the Isar proof context type is already defined early in Pure
  1877 as Context.proof (note that ProofContext.context and Proof.context are
  1878 aliases, where the latter is the preferred name).  This enables other
  1879 Isabelle components to refer to that type even before Isar is present.
  1880 
  1881 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  1882 typeK, constK, axiomK, oracleK), but provide explicit operations for
  1883 any of these kinds.  For example, Sign.intern typeK is now
  1884 Sign.intern_type, Theory.hide_space Sign.typeK is now
  1885 Theory.hide_types.  Also note that former
  1886 Theory.hide_classes/types/consts are now
  1887 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  1888 internalize their arguments!  INCOMPATIBILITY.
  1889 
  1890 * Pure: get_thm interface (of PureThy and ProofContext) expects
  1891 datatype thmref (with constructors Name and NameSelection) instead of
  1892 plain string -- INCOMPATIBILITY;
  1893 
  1894 * Pure: cases produced by proof methods specify options, where NONE
  1895 means to remove case bindings -- INCOMPATIBILITY in
  1896 (RAW_)METHOD_CASES.
  1897 
  1898 * Pure: the following operations retrieve axioms or theorems from a
  1899 theory node or theory hierarchy, respectively:
  1900 
  1901   Theory.axioms_of: theory -> (string * term) list
  1902   Theory.all_axioms_of: theory -> (string * term) list
  1903   PureThy.thms_of: theory -> (string * thm) list
  1904   PureThy.all_thms_of: theory -> (string * thm) list
  1905 
  1906 * Pure: print_tac now outputs the goal through the trace channel.
  1907 
  1908 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  1909 Reference Toplevel.debug (default false) controls detailed printing
  1910 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  1911 controls execution profiling -- set to 1 for time and 2 for space
  1912 (both increase the runtime).
  1913 
  1914 * Isar session: The initial use of ROOT.ML is now always timed,
  1915 i.e. the log will show the actual process times, in contrast to the
  1916 elapsed wall-clock time that the outer shell wrapper produces.
  1917 
  1918 * Simplifier: improved handling of bound variables (nameless
  1919 representation, avoid allocating new strings).  Simprocs that invoke
  1920 the Simplifier recursively should use Simplifier.inherit_bounds to
  1921 avoid local name clashes.  Failure to do so produces warnings
  1922 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  1923 for further details.
  1924 
  1925 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  1926 bindings for all theorems stored within a given theory; this may help
  1927 in porting non-Isar theories to Isar ones, while keeping ML proof
  1928 scripts for the time being.
  1929 
  1930 * ML operator HTML.with_charset specifies the charset begin used for
  1931 generated HTML files.  For example:
  1932 
  1933   HTML.with_charset "utf-8" use_thy "Hebrew";
  1934   HTML.with_charset "utf-8" use_thy "Chinese";
  1935 
  1936 
  1937 *** System ***
  1938 
  1939 * Allow symlinks to all proper Isabelle executables (Isabelle,
  1940 isabelle, isatool etc.).
  1941 
  1942 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  1943 isatool doc, isatool mkdir, display_drafts etc.).
  1944 
  1945 * isatool usedir: option -f allows specification of the ML file to be
  1946 used by Isabelle; default is ROOT.ML.
  1947 
  1948 * New isatool version outputs the version identifier of the Isabelle
  1949 distribution being used.
  1950 
  1951 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  1952 (containing Boolean satisfiability problems) into Isabelle/HOL
  1953 theories.
  1954 
  1955 
  1956 
  1957 New in Isabelle2004 (April 2004)
  1958 --------------------------------
  1959 
  1960 *** General ***
  1961 
  1962 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  1963   Replaces linorder.ML.
  1964 
  1965 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  1966   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  1967   (\<a>...\<z>), are now considered normal letters, and can therefore
  1968   be used anywhere where an ASCII letter (a...zA...Z) has until
  1969   now. COMPATIBILITY: This obviously changes the parsing of some
  1970   terms, especially where a symbol has been used as a binder, say
  1971   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  1972   as an identifier.  Fix it by inserting a space around former
  1973   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  1974   existing theory and ML files.
  1975 
  1976 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  1977 
  1978 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  1979   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  1980   a normal (but invisible) letter. For multiple letter subscripts repeat
  1981   \<^isub> like this: x\<^isub>1\<^isub>2.
  1982 
  1983 * Pure: There are now sub-/superscripts that can span more than one
  1984   character. Text between \<^bsub> and \<^esub> is set in subscript in
  1985   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  1986   superscript. The new control characters are not identifier parts.
  1987 
  1988 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  1989   content of "..." to the latex file instead of \isacntrl... . The "..."
  1990   may consist of any printable characters excluding the end bracket >.
  1991 
  1992 * Pure: Using new Isar command "finalconsts" (or the ML functions
  1993   Theory.add_finals or Theory.add_finals_i) it is now possible to
  1994   declare constants "final", which prevents their being given a definition
  1995   later.  It is useful for constants whose behaviour is fixed axiomatically
  1996   rather than definitionally, such as the meta-logic connectives.
  1997 
  1998 * Pure: 'instance' now handles general arities with general sorts
  1999   (i.e. intersections of classes),
  2000 
  2001 * Presentation: generated HTML now uses a CSS style sheet to make layout
  2002   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  2003   It can be changed to alter the colors/layout of generated pages.
  2004 
  2005 
  2006 *** Isar ***
  2007 
  2008 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  2009   cut_tac, subgoal_tac and thin_tac:
  2010   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  2011     locales are no longer forced to write Isar proof scripts.
  2012     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  2013     emulations.
  2014   - INCOMPATIBILITY: names of variables to be instantiated may no
  2015     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  2016     This is consistent with the instantiation attribute "where".
  2017 
  2018 * Attributes "where" and "of":
  2019   - Now take type variables of instantiated theorem into account when reading
  2020     the instantiation string.  This fixes a bug that caused instantiated
  2021     theorems to have too special types in some circumstances.
  2022   - "where" permits explicit instantiations of type variables.
  2023 
  2024 * Calculation commands "moreover" and "also" no longer interfere with
  2025   current facts ("this"), admitting arbitrary combinations with "then"
  2026   and derived forms.
  2027 
  2028 * Locales:
  2029   - Goal statements involving the context element "includes" no longer
  2030     generate theorems with internal delta predicates (those ending on
  2031     "_axioms") in the premise.
  2032     Resolve particular premise with <locale>.intro to obtain old form.
  2033   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  2034     specification and "includes" elements in goal statement.
  2035   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  2036     [intro?] and [elim?] (respectively) by default.
  2037   - Experimental command for instantiation of locales in proof contexts:
  2038         instantiate <label>[<attrs>]: <loc>
  2039     Instantiates locale <loc> and adds all its theorems to the current context
  2040     taking into account their attributes.  Label and attrs are optional
  2041     modifiers, like in theorem declarations.  If present, names of
  2042     instantiated theorems are qualified with <label>, and the attributes
  2043     <attrs> are applied after any attributes these theorems might have already.
  2044       If the locale has assumptions, a chained fact of the form
  2045     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  2046     are derived.  The command does not support old-style locales declared
  2047     with "locale (open)".
  2048       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  2049 
  2050 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  2051   (Isar) contexts.
  2052 
  2053 
  2054 *** HOL ***
  2055 
  2056 * Proof import: new image HOL4 contains the imported library from
  2057   the HOL4 system with about 2500 theorems. It is imported by
  2058   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  2059   can be used like any other Isabelle image.  See
  2060   HOL/Import/HOL/README for more information.
  2061 
  2062 * Simplifier:
  2063   - Much improved handling of linear and partial orders.
  2064     Reasoners for linear and partial orders are set up for type classes
  2065     "linorder" and "order" respectively, and are added to the default simpset
  2066     as solvers.  This means that the simplifier can build transitivity chains
  2067     to solve goals from the assumptions.
  2068   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  2069     of blast or auto after simplification become unnecessary because the goal
  2070     is solved by simplification already.
  2071 
  2072 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  2073     all proved in axiomatic type classes for semirings, rings and fields.
  2074 
  2075 * Numerics:
  2076   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  2077     now formalized using the Ring_and_Field theory mentioned above.
  2078   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  2079     than before, because now they are set up once in a generic manner.
  2080   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  2081     Look for the general versions in Ring_and_Field (and Power if they concern
  2082     exponentiation).
  2083 
  2084 * Type "rat" of the rational numbers is now available in HOL-Complex.
  2085 
  2086 * Records:
  2087   - Record types are now by default printed with their type abbreviation
  2088     instead of the list of all field types. This can be configured via
  2089     the reference "print_record_type_abbr".
  2090   - Simproc "record_upd_simproc" for simplification of multiple updates added
  2091     (not enabled by default).
  2092   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  2093     EX x. x = sel r to True (not enabled by default).
  2094   - Tactic "record_split_simp_tac" to split and simplify records added.
  2095 
  2096 * 'specification' command added, allowing for definition by
  2097   specification.  There is also an 'ax_specification' command that
  2098   introduces the new constants axiomatically.
  2099 
  2100 * arith(_tac) is now able to generate counterexamples for reals as well.
  2101 
  2102 * HOL-Algebra: new locale "ring" for non-commutative rings.
  2103 
  2104 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  2105   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  2106 
  2107 * HOL-Matrix: a first theory for matrices in HOL with an application of
  2108   matrix theory to linear programming.
  2109 
  2110 * Unions and Intersections:
  2111   The latex output syntax of UN and INT has been changed
  2112   from "\Union x \in A. B" to "\Union_{x \in A} B"
  2113   i.e. the index formulae has become a subscript.
  2114   Similarly for "\Union x. B", and for \Inter instead of \Union.
  2115 
  2116 * Unions and Intersections over Intervals:
  2117   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  2118   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  2119   like in normal math, and corresponding versions for < and for intersection.
  2120 
  2121 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  2122   lexicographic dictonary ordering has been added as "lexord".
  2123 
  2124 * ML: the legacy theory structures Int and List have been removed. They had
  2125   conflicted with ML Basis Library structures having the same names.
  2126 
  2127 * 'refute' command added to search for (finite) countermodels.  Only works
  2128   for a fragment of HOL.  The installation of an external SAT solver is
  2129   highly recommended.  See "HOL/Refute.thy" for details.
  2130 
  2131 * 'quickcheck' command: Allows to find counterexamples by evaluating
  2132   formulae under an assignment of free variables to random values.
  2133   In contrast to 'refute', it can deal with inductive datatypes,
  2134   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  2135   for examples.
  2136 
  2137 
  2138 *** HOLCF ***
  2139 
  2140 * Streams now come with concatenation and are part of the HOLCF image
  2141 
  2142 
  2143 
  2144 New in Isabelle2003 (May 2003)
  2145 ------------------------------
  2146 
  2147 *** General ***
  2148 
  2149 * Provers/simplifier:
  2150 
  2151   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  2152     Assumptions are now subject to complete mutual simplification,
  2153     not just from left to right. The simplifier now preserves
  2154     the order of assumptions.
  2155 
  2156     Potential INCOMPATIBILITY:
  2157 
  2158     -- simp sometimes diverges where the old version did
  2159        not, e.g. invoking simp on the goal
  2160 
  2161         [| P (f x); y = x; f x = f y |] ==> Q
  2162 
  2163        now gives rise to the infinite reduction sequence
  2164 
  2165         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  2166 
  2167        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  2168        kind of problem.
  2169 
  2170     -- Tactics combining classical reasoner and simplification (such as auto)
  2171        are also affected by this change, because many of them rely on
  2172        simp. They may sometimes diverge as well or yield a different numbers
  2173        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  2174        in case of problems. Sometimes subsequent calls to the classical
  2175        reasoner will fail because a preceeding call to the simplifier too
  2176        eagerly simplified the goal, e.g. deleted redundant premises.
  2177 
  2178   - The simplifier trace now shows the names of the applied rewrite rules
  2179 
  2180   - You can limit the number of recursive invocations of the simplifier
  2181     during conditional rewriting (where the simplifie tries to solve the
  2182     conditions before applying the rewrite rule):
  2183     ML "simp_depth_limit := n"
  2184     where n is an integer. Thus you can force termination where previously
  2185     the simplifier would diverge.
  2186 
  2187   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  2188 
  2189   - No longer aborts on failed congruence proof.  Instead, the
  2190     congruence is ignored.
  2191 
  2192 * Pure: New generic framework for extracting programs from constructive
  2193   proofs. See HOL/Extraction.thy for an example instantiation, as well
  2194   as HOL/Extraction for some case studies.
  2195 
  2196 * Pure: The main goal of the proof state is no longer shown by default, only
  2197 the subgoals. This behaviour is controlled by a new flag.
  2198    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  2199 (ML: Proof.show_main_goal).
  2200 
  2201 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  2202 rules whose conclusion matches subgoal 1:
  2203       PG menu: Isabelle/Isar -> Show me -> matching rules
  2204 The rules are ordered by how closely they match the subgoal.
  2205 In particular, rules that solve a subgoal outright are displayed first
  2206 (or rather last, the way they are printed).
  2207 (ML: ProofGeneral.print_intros())
  2208 
  2209 * Pure: New flag trace_unify_fail causes unification to print
  2210 diagnostic information (PG: in trace buffer) when it fails. This is
  2211 useful for figuring out why single step proofs like rule, erule or
  2212 assumption failed.
  2213 
  2214 * Pure: Locale specifications now produce predicate definitions
  2215 according to the body of text (covering assumptions modulo local
  2216 definitions); predicate "loc_axioms" covers newly introduced text,
  2217 while "loc" is cumulative wrt. all included locale expressions; the
  2218 latter view is presented only on export into the global theory
  2219 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  2220 on the old view without predicates;
  2221 
  2222 * Pure: predefined locales "var" and "struct" are useful for sharing
  2223 parameters (as in CASL, for example); just specify something like
  2224 ``var x + var y + struct M'' as import;
  2225 
  2226 * Pure: improved thms_containing: proper indexing of facts instead of
  2227 raw theorems; check validity of results wrt. current name space;
  2228 include local facts of proof configuration (also covers active
  2229 locales), cover fixed variables in index; may use "_" in term
  2230 specification; an optional limit for the number of printed facts may
  2231 be given (the default is 40);
  2232 
  2233 * Pure: disallow duplicate fact bindings within new-style theory files
  2234 (batch-mode only);
  2235 
  2236 * Provers: improved induct method: assumptions introduced by case
  2237 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  2238 the goal statement); "foo" still refers to all facts collectively;
  2239 
  2240 * Provers: the function blast.overloaded has been removed: all constants
  2241 are regarded as potentially overloaded, which improves robustness in exchange
  2242 for slight decrease in efficiency;
  2243 
  2244 * Provers/linorder: New generic prover for transitivity reasoning over
  2245 linear orders.  Note: this prover is not efficient!
  2246 
  2247 * Isar: preview of problems to finish 'show' now produce an error
  2248 rather than just a warning (in interactive mode);
  2249 
  2250 
  2251 *** HOL ***
  2252 
  2253 * arith(_tac)
  2254 
  2255  - Produces a counter example if it cannot prove a goal.
  2256    Note that the counter example may be spurious if the goal is not a formula
  2257    of quantifier-free linear arithmetic.
  2258    In ProofGeneral the counter example appears in the trace buffer.
  2259 
  2260  - Knows about div k and mod k where k is a numeral of type nat or int.
  2261 
  2262  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  2263    linear arithmetic fails. This takes account of quantifiers and divisibility.
  2264    Presburger arithmetic can also be called explicitly via presburger(_tac).
  2265 
  2266 * simp's arithmetic capabilities have been enhanced a bit: it now
  2267 takes ~= in premises into account (by performing a case split);
  2268 
  2269 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  2270 are distributed over a sum of terms;
  2271 
  2272 * New tactic "trans_tac" and method "trans" instantiate
  2273 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  2274 "<=", "<" and "=").
  2275 
  2276 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  2277 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  2278 
  2279 * 'typedef' command has new option "open" to suppress the set
  2280 definition;
  2281 
  2282 * functions Min and Max on finite sets have been introduced (theory
  2283 Finite_Set);
  2284 
  2285 * attribute [symmetric] now works for relations as well; it turns
  2286 (x,y) : R^-1 into (y,x) : R, and vice versa;
  2287 
  2288 * induct over a !!-quantified statement (say !!x1..xn):
  2289   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  2290 
  2291 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  2292 %x. None. Warning: empty_def now refers to the previously hidden definition
  2293 of the empty set.
  2294 
  2295 * Algebra: formalization of classical algebra.  Intended as base for
  2296 any algebraic development in Isabelle.  Currently covers group theory
  2297 (up to Sylow's theorem) and ring theory (Universal Property of
  2298 Univariate Polynomials).  Contributions welcome;
  2299 
  2300 * GroupTheory: deleted, since its material has been moved to Algebra;
  2301 
  2302 * Complex: new directory of the complex numbers with numeric constants,
  2303 nonstandard complex numbers, and some complex analysis, standard and
  2304 nonstandard (Jacques Fleuriot);
  2305 
  2306 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  2307 
  2308 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  2309 Fleuriot);
  2310 
  2311 * Real/HahnBanach: updated and adapted to locales;
  2312 
  2313 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  2314 Gray and Kramer);
  2315 
  2316 * UNITY: added the Meier-Sanders theory of progress sets;
  2317 
  2318 * MicroJava: bytecode verifier and lightweight bytecode verifier
  2319 as abstract algorithms, instantiated to the JVM;
  2320 
  2321 * Bali: Java source language formalization. Type system, operational
  2322 semantics, axiomatic semantics. Supported language features:
  2323 classes, interfaces, objects,virtual methods, static methods,
  2324 static/instance fields, arrays, access modifiers, definite
  2325 assignment, exceptions.
  2326 
  2327 
  2328 *** ZF ***
  2329 
  2330 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  2331 universe, etc.);
  2332 
  2333 * Main ZF: virtually all theories converted to new-style format;
  2334 
  2335 
  2336 *** ML ***
  2337 
  2338 * Pure: Tactic.prove provides sane interface for internal proofs;
  2339 omits the infamous "standard" operation, so this is more appropriate
  2340 than prove_goalw_cterm in many situations (e.g. in simprocs);
  2341 
  2342 * Pure: improved error reporting of simprocs;
  2343 
  2344 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  2345 up simprocs;
  2346 
  2347 
  2348 *** Document preparation ***
  2349 
  2350 * uses \par instead of \\ for line breaks in theory text. This may
  2351 shift some page breaks in large documents. To get the old behaviour
  2352 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  2353 
  2354 * minimized dependencies of isabelle.sty and isabellesym.sty on
  2355 other packages
  2356 
  2357 * \<euro> now needs package babel/greek instead of marvosym (which
  2358 broke \Rightarrow)
  2359 
  2360 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  2361 textcomp package)
  2362 
  2363 
  2364 
  2365 New in Isabelle2002 (March 2002)
  2366 --------------------------------
  2367 
  2368 *** Document preparation ***
  2369 
  2370 * greatly simplified document preparation setup, including more
  2371 graceful interpretation of isatool usedir -i/-d/-D options, and more
  2372 instructive isatool mkdir; users should basically be able to get
  2373 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  2374 users may run a separate document processing stage manually like this:
  2375 "isatool usedir -D output HOL Test && isatool document Test/output";
  2376 
  2377 * theory dependency graph may now be incorporated into documents;
  2378 isatool usedir -g true will produce session_graph.eps/.pdf for use
  2379 with \includegraphics of LaTeX;
  2380 
  2381 * proper spacing of consecutive markup elements, especially text
  2382 blocks after section headings;
  2383 
  2384 * support bold style (for single symbols only), input syntax is like
  2385 this: "\<^bold>\<alpha>" or "\<^bold>A";
  2386 
  2387 * \<bullet> is now output as bold \cdot by default, which looks much
  2388 better in printed text;
  2389 
  2390 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  2391 note that these symbols are currently unavailable in Proof General /
  2392 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  2393 
  2394 * isatool latex no longer depends on changed TEXINPUTS, instead
  2395 isatool document copies the Isabelle style files to the target
  2396 location;
  2397 
  2398 
  2399 *** Isar ***
  2400 
  2401 * Pure/Provers: improved proof by cases and induction;
  2402   - 'case' command admits impromptu naming of parameters (such as
  2403     "case (Suc n)");
  2404   - 'induct' method divinates rule instantiation from the inductive
  2405     claim; no longer requires excessive ?P bindings for proper
  2406     instantiation of cases;
  2407   - 'induct' method properly enumerates all possibilities of set/type
  2408     rules; as a consequence facts may be also passed through *type*
  2409     rules without further ado;
  2410   - 'induct' method now derives symbolic cases from the *rulified*
  2411     rule (before it used to rulify cases stemming from the internal
  2412     atomized version); this means that the context of a non-atomic
  2413     statement becomes is included in the hypothesis, avoiding the
  2414     slightly cumbersome show "PROP ?case" form;
  2415   - 'induct' may now use elim-style induction rules without chaining
  2416     facts, using ``missing'' premises from the goal state; this allows
  2417     rules stemming from inductive sets to be applied in unstructured
  2418     scripts, while still benefitting from proper handling of non-atomic
  2419     statements; NB: major inductive premises need to be put first, all
  2420     the rest of the goal is passed through the induction;
  2421   - 'induct' proper support for mutual induction involving non-atomic
  2422     rule statements (uses the new concept of simultaneous goals, see
  2423     below);
  2424   - append all possible rule selections, but only use the first
  2425     success (no backtracking);
  2426   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  2427   - undeclared rule case names default to numbers 1, 2, 3, ...;
  2428   - added 'print_induct_rules' (covered by help item in recent Proof
  2429     General versions);
  2430   - moved induct/cases attributes to Pure, methods to Provers;
  2431   - generic method setup instantiated for FOL and HOL;
  2432 
  2433 * Pure: support multiple simultaneous goal statements, for example
  2434 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  2435 meta-level mechanism, this acts as if several individual goals had
  2436 been stated separately; in particular common proof methods need to be
  2437 repeated in order to cover all claims; note that a single elimination
  2438 step is *not* sufficient to establish the two conjunctions, so this
  2439 fails:
  2440 
  2441   assume "A & B" then have A and B ..   (*".." fails*)
  2442 
  2443 better use "obtain" in situations as above; alternative refer to
  2444 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  2445 
  2446 * Pure: proper integration with ``locales''; unlike the original
  2447 version by Florian Kammller, Isar locales package high-level proof
  2448 contexts rather than raw logical ones (e.g. we admit to include
  2449 attributes everywhere); operations on locales include merge and
  2450 rename; support for implicit arguments (``structures''); simultaneous
  2451 type-inference over imports and text; see also HOL/ex/Locales.thy for
  2452 some examples;
  2453 
  2454 * Pure: the following commands have been ``localized'', supporting a
  2455 target locale specification "(in name)": 'lemma', 'theorem',
  2456 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  2457 stored both within the locale and at the theory level (exported and
  2458 qualified by the locale name);
  2459 
  2460 * Pure: theory goals may now be specified in ``long'' form, with
  2461 ad-hoc contexts consisting of arbitrary locale elements. for example
  2462 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  2463 definitions may be given, too); the result is a meta-level rule with
  2464 the context elements being discharged in the obvious way;
  2465 
  2466 * Pure: new proof command 'using' allows to augment currently used
  2467 facts after a goal statement ('using' is syntactically analogous to
  2468 'apply', but acts on the goal's facts only); this allows chained facts
  2469 to be separated into parts given before and after a claim, as in
  2470 ``from a and b have C using d and e <proof>'';
  2471 
  2472 * Pure: renamed "antecedent" case to "rule_context";
  2473 
  2474 * Pure: new 'judgment' command records explicit information about the
  2475 object-logic embedding (used by several tools internally); no longer
  2476 use hard-wired "Trueprop";
  2477 
  2478 * Pure: added 'corollary' command;
  2479 
  2480 * Pure: fixed 'token_translation' command;
  2481 
  2482 * Pure: removed obsolete 'exported' attribute;
  2483 
  2484 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  2485 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  2486 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  2487 
  2488 * Pure: method 'atomize' presents local goal premises as object-level
  2489 statements (atomic meta-level propositions); setup controlled via
  2490 rewrite rules declarations of 'atomize' attribute; example
  2491 application: 'induct' method with proper rule statements in improper
  2492 proof *scripts*;
  2493 
  2494 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  2495 now consider the syntactic context of assumptions, giving a better
  2496 chance to get type-inference of the arguments right (this is
  2497 especially important for locales);
  2498 
  2499 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  2500 mode;
  2501 
  2502 * Pure/obtain: the formal conclusion "thesis", being marked as
  2503 ``internal'', may no longer be reference directly in the text;
  2504 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  2505 situations;
  2506 
  2507 * Pure: generic 'sym' attribute which declares a rule both as pure
  2508 'elim?' and for the 'symmetric' operation;
  2509 
  2510 * Pure: marginal comments ``--'' may now occur just anywhere in the
  2511 text; the fixed correlation with particular command syntax has been
  2512 discontinued;
  2513 
  2514 * Pure: new method 'rules' is particularly well-suited for proof
  2515 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  2516 but often produces more compact proof terms with less detours;
  2517 
  2518 * Pure/Provers/classical: simplified integration with pure rule
  2519 attributes and methods; the classical "intro?/elim?/dest?"
  2520 declarations coincide with the pure ones; the "rule" method no longer
  2521 includes classically swapped intros; "intro" and "elim" methods no
  2522 longer pick rules from the context; also got rid of ML declarations
  2523 AddXIs/AddXEs/AddXDs; all of this has some potential for
  2524 INCOMPATIBILITY;
  2525 
  2526 * Provers/classical: attribute 'swapped' produces classical inversions
  2527 of introduction rules;
  2528 
  2529 * Provers/simplifier: 'simplified' attribute may refer to explicit
  2530 rules instead of full simplifier context; 'iff' attribute handles
  2531 conditional rules;
  2532 
  2533 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  2534 
  2535 * HOL: 'recdef' now fails on unfinished automated proofs, use
  2536 "(permissive)" option to recover old behavior;
  2537 
  2538 * HOL: 'inductive' no longer features separate (collective) attributes
  2539 for 'intros' (was found too confusing);
  2540 
  2541 * HOL: properly declared induction rules less_induct and
  2542 wf_induct_rule;
  2543 
  2544 
  2545 *** HOL ***
  2546 
  2547 * HOL: moved over to sane numeral syntax; the new policy is as
  2548 follows:
  2549 
  2550   - 0 and 1 are polymorphic constants, which are defined on any
  2551   numeric type (nat, int, real etc.);
  2552 
  2553   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  2554   binary representation internally;
  2555 
  2556   - type nat has special constructor Suc, and generally prefers Suc 0
  2557   over 1::nat and Suc (Suc 0) over 2::nat;
  2558 
  2559 This change may cause significant problems of INCOMPATIBILITY; here
  2560 are some hints on converting existing sources:
  2561 
  2562   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  2563   entities, so expressions involving "-" (unary or binary minus) need
  2564   to be spaced properly;
  2565 
  2566   - existing occurrences of "1" may need to be constraint "1::nat" or
  2567   even replaced by Suc 0; similar for old "2";
  2568 
  2569   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  2570 
  2571   - remove all special provisions on numerals in proofs;
  2572 
  2573 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  2574 representation (depends on bin_arith_simps in the default context);
  2575 
  2576 * HOL: symbolic syntax for x^2 (numeral 2);
  2577 
  2578 * HOL: the class of all HOL types is now called "type" rather than
  2579 "term"; INCOMPATIBILITY, need to adapt references to this type class
  2580 in axclass/classes, instance/arities, and (usually rare) occurrences
  2581 in typings (of consts etc.); internally the class is called
  2582 "HOL.type", ML programs should refer to HOLogic.typeS;
  2583 
  2584 * HOL/record package improvements:
  2585   - new derived operations "fields" to build a partial record section,
  2586     "extend" to promote a fixed record to a record scheme, and
  2587     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  2588     declared as simp by default;
  2589   - shared operations ("more", "fields", etc.) now need to be always
  2590     qualified) --- potential INCOMPATIBILITY;
  2591   - removed "make_scheme" operations (use "make" with "extend") --
  2592     INCOMPATIBILITY;
  2593   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  2594   - provides cases/induct rules for use with corresponding Isar
  2595     methods (for concrete records, record schemes, concrete more
  2596     parts, and schematic more parts -- in that order);
  2597   - internal definitions directly based on a light-weight abstract
  2598     theory of product types over typedef rather than datatype;
  2599 
  2600 * HOL: generic code generator for generating executable ML code from
  2601 specifications; specific support for HOL constructs such as inductive
  2602 datatypes and sets, as well as recursive functions; can be invoked
  2603 via 'generate_code' theory section;
  2604 
  2605 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  2606 
  2607 * HOL: consolidated and renamed several theories.  In particular:
  2608         Ord.thy has been absorbed into HOL.thy
  2609         String.thy has been absorbed into List.thy
  2610 
  2611 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  2612 (beware of argument permutation!);
  2613 
  2614 * HOL: linorder_less_split superseded by linorder_cases;
  2615 
  2616 * HOL/List: "nodups" renamed to "distinct";
  2617 
  2618 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  2619 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  2620   - Ex_def has changed, now need to use some_eq_ex
  2621 
  2622 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  2623 in this (rare) case use:
  2624 
  2625   delSWrapper "split_all_tac"
  2626   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  2627 
  2628 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  2629 MAY FAIL;
  2630 
  2631 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  2632 Isabelle's type classes, ^ on functions and relations has too general
  2633 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  2634 necessary to attach explicit type constraints;
  2635 
  2636 * HOL/Relation: the prefix name of the infix "O" has been changed from
  2637 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  2638 renamed accordingly (eg "compI" -> "rel_compI").
  2639 
  2640 * HOL: syntax translations now work properly with numerals and records
  2641 expressions;
  2642 
  2643 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  2644 of "lam" -- INCOMPATIBILITY;
  2645 
  2646 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  2647 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  2648 renamed "Product_Type.unit";
  2649 
  2650 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  2651 
  2652 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  2653 the "cases" method);
  2654 
  2655 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  2656 Florian Kammller);
  2657 
  2658 * HOL/IMP: updated and converted to new-style theory format; several
  2659 parts turned into readable document, with proper Isar proof texts and
  2660 some explanations (by Gerwin Klein);
  2661 
  2662 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  2663 
  2664 * HOL-Hyperreal is now a logic image;
  2665 
  2666 
  2667 *** HOLCF ***
  2668 
  2669 * Isar: consts/constdefs supports mixfix syntax for continuous
  2670 operations;
  2671 
  2672 * Isar: domain package adapted to new-style theory format, e.g. see
  2673 HOLCF/ex/Dnat.thy;
  2674 
  2675 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  2676 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  2677 lift.induct_tac, always use UU instead of Undef;
  2678 
  2679 * HOLCF/IMP: updated and converted to new-style theory;
  2680 
  2681 
  2682 *** ZF ***
  2683 
  2684 * Isar: proper integration of logic-specific tools and packages,
  2685 including theory commands '(co)inductive', '(co)datatype',
  2686 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  2687 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  2688 
  2689 * theory Main no longer includes AC; for the Axiom of Choice, base
  2690 your theory on Main_ZFC;
  2691 
  2692 * the integer library now covers quotients and remainders, with many
  2693 laws relating division to addition, multiplication, etc.;
  2694 
  2695 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  2696 typeless version of the formalism;
  2697 
  2698 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  2699 format;
  2700 
  2701 * ZF/Induct: new directory for examples of inductive definitions,
  2702 including theory Multiset for multiset orderings; converted to
  2703 new-style theory format;
  2704 
  2705 * ZF: many new theorems about lists, ordinals, etc.;
  2706 
  2707 
  2708 *** General ***
  2709 
  2710 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  2711 variable proof controls level of detail: 0 = no proofs (only oracle
  2712 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  2713 also ref manual for further ML interfaces;
  2714 
  2715 * Pure/axclass: removed obsolete ML interface
  2716 goal_subclass/goal_arity;
  2717 
  2718 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  2719 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  2720 separate tokens, so expressions involving minus need to be spaced
  2721 properly;
  2722 
  2723 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  2724 rather than "infixl" or "infixr";
  2725 
  2726 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  2727 sort constraint specifications in type inference; e.g. "x::_::foo"
  2728 ensures that the type of "x" is of sort "foo" (but not necessarily a
  2729 type variable);
  2730 
  2731 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  2732 control output of nested => (types); the default behavior is
  2733 "type_brackets";
  2734 
  2735 * Pure/syntax: builtin parse translation for "_constify" turns valued
  2736 tokens into AST constants;
  2737 
  2738 * Pure/syntax: prefer later declarations of translations and print
  2739 translation functions; potential INCOMPATIBILITY: need to reverse
  2740 multiple declarations for same syntax element constant;
  2741 
  2742 * Pure/show_hyps reset by default (in accordance to existing Isar
  2743 practice);
  2744 
  2745 * Provers/classical: renamed addaltern to addafter, addSaltern to
  2746 addSafter;
  2747 
  2748 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  2749 as well;
  2750 
  2751 * system: tested support for MacOS X; should be able to get Isabelle +
  2752 Proof General to work in a plain Terminal after installing Poly/ML
  2753 (e.g. from the Isabelle distribution area) and GNU bash alone
  2754 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  2755 support requires further installations, e.g. from
  2756 http://fink.sourceforge.net/);
  2757 
  2758 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  2759 
  2760 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  2761 of 40 MB), cf. ML_OPTIONS;
  2762 
  2763 * system: Proof General keywords specification is now part of the
  2764 Isabelle distribution (see etc/isar-keywords.el);
  2765 
  2766 * system: support for persistent Proof General sessions (refrain from
  2767 outdating all loaded theories on startup); user may create writable
  2768 logic images like this: ``isabelle -q HOL Test'';
  2769 
  2770 * system: smart selection of Isabelle process versus Isabelle
  2771 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  2772 run both "isabelle" and "Isabelle" even if file names are badly
  2773 damaged (executable inspects the case of the first letter of its own
  2774 name); added separate "isabelle-process" and "isabelle-interface";
  2775 
  2776 * system: refrain from any attempt at filtering input streams; no
  2777 longer support ``8bit'' encoding of old isabelle font, instead proper
  2778 iso-latin characters may now be used; the related isatools
  2779 "symbolinput" and "nonascii" have disappeared as well;
  2780 
  2781 * system: removed old "xterm" interface (the print modes "xterm" and
  2782 "xterm_color" are still available for direct use in a suitable
  2783 terminal);
  2784 
  2785 
  2786 
  2787 New in Isabelle99-2 (February 2001)
  2788 -----------------------------------
  2789 
  2790 *** Overview of INCOMPATIBILITIES ***
  2791 
  2792 * HOL: please note that theories in the Library and elsewhere often use the
  2793 new-style (Isar) format; to refer to their theorems in an ML script you must
  2794 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  2795 
  2796 * HOL: inductive package no longer splits induction rule aggressively,
  2797 but only as far as specified by the introductions given; the old
  2798 format may be recovered via ML function complete_split_rule or attribute
  2799 'split_rule (complete)';
  2800 
  2801 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  2802 gfp_Tarski to gfp_unfold;
  2803 
  2804 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  2805 
  2806 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  2807 relation); infix "^^" has been renamed "``"; infix "``" has been
  2808 renamed "`"; "univalent" has been renamed "single_valued";
  2809 
  2810 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  2811 operation;
  2812 
  2813 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  2814 
  2815 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  2816 
  2817 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  2818 consequence, it is no longer monotonic wrt. the local goal context
  2819 (which is now passed through the inductive cases);
  2820 
  2821 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  2822 \<gg> to \<ggreater>;
  2823 
  2824 
  2825 *** Document preparation ***
  2826 
  2827 * \isabellestyle{NAME} selects version of Isabelle output (currently
  2828 available: are "it" for near math-mode best-style output, "sl" for
  2829 slanted text style, and "tt" for plain type-writer; if no
  2830 \isabellestyle command is given, output is according to slanted
  2831 type-writer);
  2832 
  2833 * support sub/super scripts (for single symbols only), input syntax is
  2834 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  2835 
  2836 * some more standard symbols; see Appendix A of the system manual for
  2837 the complete list of symbols defined in isabellesym.sty;
  2838 
  2839 * improved isabelle style files; more abstract symbol implementation
  2840 (should now use \isamath{...} and \isatext{...} in custom symbol
  2841 definitions);
  2842 
  2843 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  2844 state; Note that presentation of goal states does not conform to
  2845 actual human-readable proof documents.  Please do not include goal
  2846 states into document output unless you really know what you are doing!
  2847 
  2848 * proper indentation of antiquoted output with proportional LaTeX
  2849 fonts;
  2850 
  2851 * no_document ML operator temporarily disables LaTeX document
  2852 generation;
  2853 
  2854 * isatool unsymbolize tunes sources for plain ASCII communication;
  2855 
  2856 
  2857 *** Isar ***
  2858 
  2859 * Pure: Isar now suffers initial goal statements to contain unbound
  2860 schematic variables (this does not conform to actual readable proof
  2861 documents, due to unpredictable outcome and non-compositional proof
  2862 checking); users who know what they are doing may use schematic goals
  2863 for Prolog-style synthesis of proven results;
  2864 
  2865 * Pure: assumption method (an implicit finishing) now handles actual
  2866 rules as well;
  2867 
  2868 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  2869 initial goal, declare "that" only as Pure intro (only for single
  2870 steps); the "that" rule assumption may now be involved in implicit
  2871 finishing, thus ".." becomes a feasible for trivial obtains;
  2872 
  2873 * Pure: default proof step now includes 'intro_classes'; thus trivial
  2874 instance proofs may be performed by "..";
  2875 
  2876 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  2877 statements as well;
  2878 
  2879 * Pure: more robust selection of calculational rules;
  2880 
  2881 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  2882 rule (as well as the assumption rule);
  2883 
  2884 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  2885 lemmas, using the graph browser tool;
  2886 
  2887 * Pure: predict failure of "show" in interactive mode;
  2888 
  2889 * Pure: 'thms_containing' now takes actual terms as arguments;
  2890 
  2891 * HOL: improved method 'induct' --- now handles non-atomic goals
  2892 (potential INCOMPATIBILITY); tuned error handling;
  2893 
  2894 * HOL: cases and induct rules now provide explicit hints about the
  2895 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  2896 any remaining facts are inserted into the goal verbatim;
  2897 
  2898 * HOL: local contexts (aka cases) may now contain term bindings as
  2899 well; the 'cases' and 'induct' methods new provide a ?case binding for
  2900 the result to be shown in each case;
  2901 
  2902 * HOL: added 'recdef_tc' command;
  2903 
  2904 * isatool convert assists in eliminating legacy ML scripts;
  2905 
  2906 
  2907 *** HOL ***
  2908 
  2909 * HOL/Library: a collection of generic theories to be used together
  2910 with main HOL; the theory loader path already includes this directory
  2911 by default; the following existing theories have been moved here:
  2912 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  2913 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  2914 
  2915 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  2916 modelling and verification task performed in Isabelle/HOL +
  2917 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  2918 
  2919 * HOL/Algebra: special summation operator SUM no longer exists, it has
  2920 been replaced by setsum; infix 'assoc' now has priority 50 (like
  2921 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  2922 'domain', this makes the theory consistent with mathematical
  2923 literature;
  2924 
  2925 * HOL basics: added overloaded operations "inverse" and "divide"
  2926 (infix "/"), syntax for generic "abs" operation, generic summation
  2927 operator \<Sum>;
  2928 
  2929 * HOL/typedef: simplified package, provide more useful rules (see also
  2930 HOL/subset.thy);
  2931 
  2932 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  2933 now expressed as a proper nested rule (old-style tactic scripts may
  2934 require atomize_strip_tac to cope with non-atomic premises);
  2935 
  2936 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  2937 to "split_conv" (old name still available for compatibility);
  2938 
  2939 * HOL: improved concrete syntax for strings (e.g. allows translation
  2940 rules with string literals);
  2941 
  2942 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  2943  and Fleuriot's mechanization of analysis, including the transcendental
  2944  functions for the reals;
  2945 
  2946 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  2947 
  2948 
  2949 *** CTT ***
  2950 
  2951 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  2952 "lam" is displayed as TWO lambda-symbols
  2953 
  2954 * CTT: theory Main now available, containing everything (that is, Bool
  2955 and Arith);
  2956 
  2957 
  2958 *** General ***
  2959 
  2960 * Pure: the Simplifier has been implemented properly as a derived rule
  2961 outside of the actual kernel (at last!); the overall performance
  2962 penalty in practical applications is about 50%, while reliability of
  2963 the Isabelle inference kernel has been greatly improved;
  2964 
  2965 * print modes "brackets" and "no_brackets" control output of nested =>
  2966 (types) and ==> (props); the default behaviour is "brackets";
  2967 
  2968 * Provers: fast_tac (and friends) now handle actual object-logic rules
  2969 as assumptions as well;
  2970 
  2971 * system: support Poly/ML 4.0;
  2972 
  2973 * system: isatool install handles KDE version 1 or 2;
  2974 
  2975 
  2976 
  2977 New in Isabelle99-1 (October 2000)
  2978 ----------------------------------
  2979 
  2980 *** Overview of INCOMPATIBILITIES ***
  2981 
  2982 * HOL: simplification of natural numbers is much changed; to partly
  2983 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  2984 issue the following ML commands:
  2985 
  2986   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  2987   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  2988 
  2989 * HOL: simplification no longer dives into case-expressions; this is
  2990 controlled by "t.weak_case_cong" for each datatype t;
  2991 
  2992 * HOL: nat_less_induct renamed to less_induct;
  2993 
  2994 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  2995 fixsome to patch .thy and .ML sources automatically;
  2996 
  2997   select_equality  -> some_equality
  2998   select_eq_Ex     -> some_eq_ex
  2999   selectI2EX       -> someI2_ex
  3000   selectI2         -> someI2
  3001   selectI          -> someI
  3002   select1_equality -> some1_equality
  3003   Eps_sym_eq       -> some_sym_eq_trivial
  3004   Eps_eq           -> some_eq_trivial
  3005 
  3006 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  3007 
  3008 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  3009 instead);
  3010 
  3011 * HOL: the recursion equations generated by 'recdef' are now called
  3012 f.simps instead of f.rules;
  3013 
  3014 * HOL: qed_spec_mp now also handles bounded ALL as well;
  3015 
  3016 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  3017 sometimes be needed;
  3018 
  3019 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  3020 
  3021 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  3022 
  3023 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  3024 product is now "<*>" instead of "Times"; the lexicographic product is
  3025 now "<*lex*>" instead of "**";
  3026 
  3027 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  3028 of main HOL, but was unused); better use HOL's datatype package;
  3029 
  3030 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  3031 the old syntax may be recovered as follows:
  3032 
  3033   syntax (symbols)
  3034     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  3035       (infixl "\\<oplus>" 100)
  3036 
  3037 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3038 
  3039 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  3040 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  3041 internally;
  3042 
  3043 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  3044 changed from A/r to A//r;
  3045 
  3046 * ZF: new treatment of arithmetic (nat & int) may break some old
  3047 proofs;
  3048 
  3049 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  3050 rulify -> rule_format, elimify -> elim_format, ...);
  3051 
  3052 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3053 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  3054 should have to change intro!! to intro? only); replaced "delrule" by
  3055 "rule del";
  3056 
  3057 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  3058 
  3059 * Provers: strengthened force_tac by using new first_best_tac;
  3060 
  3061 * LaTeX document preparation: several changes of isabelle.sty (see
  3062 lib/texinputs);
  3063 
  3064 
  3065 *** Document preparation ***
  3066 
  3067 * formal comments (text blocks etc.) in new-style theories may now
  3068 contain antiquotations of thm/prop/term/typ/text to be presented
  3069 according to latex print mode; concrete syntax is like this:
  3070 @{term[show_types] "f(x) = a + x"};
  3071 
  3072 * isatool mkdir provides easy setup of Isabelle session directories,
  3073 including proper document sources;
  3074 
  3075 * generated LaTeX sources are now deleted after successful run
  3076 (isatool document -c); may retain a copy somewhere else via -D option
  3077 of isatool usedir;
  3078 
  3079 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  3080 style files, achieving self-contained LaTeX sources and simplifying
  3081 LaTeX debugging;
  3082 
  3083 * old-style theories now produce (crude) LaTeX output as well;
  3084 
  3085 * browser info session directories are now self-contained (may be put
  3086 on WWW server seperately); improved graphs of nested sessions; removed
  3087 graph for 'all sessions';
  3088 
  3089 * several improvements in isabelle style files; \isabellestyle{it}
  3090 produces fake math mode output; \isamarkupheader is now \section by
  3091 default; see lib/texinputs/isabelle.sty etc.;
  3092 
  3093 
  3094 *** Isar ***
  3095 
  3096 * Isar/Pure: local results and corresponding term bindings are now
  3097 subject to Hindley-Milner polymorphism (similar to ML); this
  3098 accommodates incremental type-inference very nicely;
  3099 
  3100 * Isar/Pure: new derived language element 'obtain' supports
  3101 generalized existence reasoning;
  3102 
  3103 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  3104 support accumulation of results, without applying any rules yet;
  3105 useful to collect intermediate results without explicit name
  3106 references, and for use with transitivity rules with more than 2
  3107 premises;
  3108 
  3109 * Isar/Pure: scalable support for case-analysis type proofs: new
  3110 'case' language element refers to local contexts symbolically, as
  3111 produced by certain proof methods; internally, case names are attached
  3112 to theorems as "tags";
  3113 
  3114 * Isar/Pure: theory command 'hide' removes declarations from
  3115 class/type/const name spaces;
  3116 
  3117 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  3118 indicate potential overloading;
  3119 
  3120 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  3121 
  3122 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  3123 "{a,b,c}" instead of {a,b,c};
  3124 
  3125 * Isar/Pure now provides its own version of intro/elim/dest
  3126 attributes; useful for building new logics, but beware of confusion
  3127 with the version in Provers/classical;
  3128 
  3129 * Isar/Pure: the local context of (non-atomic) goals is provided via
  3130 case name 'antecedent';
  3131 
  3132 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  3133 to the current context is now done automatically);
  3134 
  3135 * Isar/Pure: theory command 'method_setup' provides a simple interface
  3136 for definining proof methods in ML;
  3137 
  3138 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3139 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  3140 most cases, one should have to change intro!! to intro? only);
  3141 replaced "delrule" by "rule del";
  3142 
  3143 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  3144 'symmetric' attribute (the latter supercedes [RS sym]);
  3145 
  3146 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  3147 method modifier); 'simp' method: 'only:' modifier removes loopers as
  3148 well (including splits);
  3149 
  3150 * Isar/Provers: Simplifier and Classical methods now support all kind
  3151 of modifiers used in the past, including 'cong', 'iff', etc.
  3152 
  3153 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  3154 of Simplifier and Classical reasoner);
  3155 
  3156 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  3157 now support named cases; major packages (inductive, datatype, primrec,
  3158 recdef) support case names and properly name parameters;
  3159 
  3160 * Isar/HOL: new transitivity rules for substitution in inequalities --
  3161 monotonicity conditions are extracted to be proven at end of
  3162 calculations;
  3163 
  3164 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  3165 method anyway;
  3166 
  3167 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  3168 split_if split_if_asm; datatype package provides theorems foo.splits =
  3169 foo.split foo.split_asm for each datatype;
  3170 
  3171 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  3172 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  3173 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  3174 use "(cases (simplified))" method in proper proof texts);
  3175 
  3176 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  3177 
  3178 * Isar: names of theorems etc. may be natural numbers as well;
  3179 
  3180 * Isar: 'pr' command: optional arguments for goals_limit and
  3181 ProofContext.prems_limit; no longer prints theory contexts, but only
  3182 proof states;
  3183 
  3184 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  3185 additional print modes to be specified; e.g. "pr(latex)" will print
  3186 proof state according to the Isabelle LaTeX style;
  3187 
  3188 * Isar: improved support for emulating tactic scripts, including proof
  3189 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  3190 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  3191 (for HOL datatypes);
  3192 
  3193 * Isar: simplified (more robust) goal selection of proof methods: 1st
  3194 goal, all goals, or explicit goal specifier (tactic emulation); thus
  3195 'proof method scripts' have to be in depth-first order;
  3196 
  3197 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  3198 
  3199 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  3200 should instead use individual commands for printing items
  3201 (print_commands, print_methods etc.);
  3202 
  3203 * Isar: added 'nothing' --- the empty list of theorems;
  3204 
  3205 
  3206 *** HOL ***
  3207 
  3208 * HOL/MicroJava: formalization of a fragment of Java, together with a
  3209 corresponding virtual machine and a specification of its bytecode
  3210 verifier and a lightweight bytecode verifier, including proofs of
  3211 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  3212 Cornelia Pusch (see also the homepage of project Bali at
  3213 http://isabelle.in.tum.de/Bali/);
  3214 
  3215 * HOL/Algebra: new theory of rings and univariate polynomials, by
  3216 Clemens Ballarin;
  3217 
  3218 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  3219 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  3220 Rasmussen;
  3221 
  3222 * HOL/Lattice: fundamental concepts of lattice theory and order
  3223 structures, including duals, properties of bounds versus algebraic
  3224 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  3225 Theorem for complete lattices etc.; may also serve as a demonstration
  3226 for abstract algebraic reasoning using axiomatic type classes, and
  3227 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  3228 
  3229 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  3230 von Oheimb;
  3231 
  3232 * HOL/IMPP: extension of IMP with local variables and mutually
  3233 recursive procedures, by David von Oheimb;
  3234 
  3235 * HOL/Lambda: converted into new-style theory and document;
  3236 
  3237 * HOL/ex/Multiquote: example of multiple nested quotations and
  3238 anti-quotations -- basically a generalized version of de-Bruijn
  3239 representation; very useful in avoiding lifting of operations;
  3240 
  3241 * HOL/record: added general record equality rule to simpset; fixed
  3242 select-update simplification procedure to handle extended records as
  3243 well; admit "r" as field name;
  3244 
  3245 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  3246 other numeric types and also as the identity of groups, rings, etc.;
  3247 
  3248 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  3249 Types nat and int belong to this axclass;
  3250 
  3251 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  3252    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  3253    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  3254   two terms #m*u and #n*u are replaced by #(m+n)*u
  3255     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  3256   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  3257     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  3258 
  3259 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  3260 powerful prover for predicate logic but knows nothing of clasets; see
  3261 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  3262 
  3263 * HOL: new version of "case_tac" subsumes both boolean case split and
  3264 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  3265 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  3266 
  3267 * HOL: simplification no longer dives into case-expressions: only the
  3268 selector expression is simplified, but not the remaining arms; to
  3269 enable full simplification of case-expressions for datatype t, you may
  3270 remove t.weak_case_cong from the simpset, either globally (Delcongs
  3271 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  3272 
  3273 * HOL/recdef: the recursion equations generated by 'recdef' for
  3274 function 'f' are now called f.simps instead of f.rules; if all
  3275 termination conditions are proved automatically, these simplification
  3276 rules are added to the simpset, as in primrec; rules may be named
  3277 individually as well, resulting in a separate list of theorems for
  3278 each equation;
  3279 
  3280 * HOL/While is a new theory that provides a while-combinator. It
  3281 permits the definition of tail-recursive functions without the
  3282 provision of a termination measure. The latter is necessary once the
  3283 invariant proof rule for while is applied.
  3284 
  3285 * HOL: new (overloaded) notation for the set of elements below/above
  3286 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  3287 
  3288 * HOL: theorems impI, allI, ballI bound as "strip";
  3289 
  3290 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  3291 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  3292 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  3293 
  3294 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3295 
  3296 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  3297 main HOL, but was unused);
  3298 
  3299 * HOL: fewer consts declared as global (e.g. have to refer to
  3300 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  3301 
  3302 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  3303 in case of overlap with user translations (e.g. judgements over
  3304 tuples); (note that the underlying logical represenation is still
  3305 bogus);
  3306 
  3307 
  3308 *** ZF ***
  3309 
  3310 * ZF: simplification automatically cancels common terms in arithmetic
  3311 expressions over nat and int;
  3312 
  3313 * ZF: new treatment of nat to minimize type-checking: all operators
  3314 coerce their operands to a natural number using the function natify,
  3315 making the algebraic laws unconditional;
  3316 
  3317 * ZF: as above, for int: operators coerce their operands to an integer
  3318 using the function intify;
  3319 
  3320 * ZF: the integer library now contains many of the usual laws for the
  3321 orderings, including $<=, and monotonicity laws for $+ and $*;
  3322 
  3323 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  3324 simplification;
  3325 
  3326 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  3327 to the simplifier and classical reasoner simultaneously;
  3328 
  3329 
  3330 *** General ***
  3331 
  3332 * Provers: blast_tac now handles actual object-logic rules as
  3333 assumptions; note that auto_tac uses blast_tac internally as well;
  3334 
  3335 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  3336 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  3337 
  3338 * Provers: delrules now handles destruct rules as well (no longer need
  3339 explicit make_elim);
  3340 
  3341 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  3342   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3343 use instead the strong form,
  3344   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3345 in HOL, FOL and ZF the function cla_make_elim will create such rules
  3346 from destruct-rules;
  3347 
  3348 * Provers: Simplifier.easy_setup provides a fast path to basic
  3349 Simplifier setup for new object-logics;
  3350 
  3351 * Pure: AST translation rules no longer require constant head on LHS;
  3352 
  3353 * Pure: improved name spaces: ambiguous output is qualified; support
  3354 for hiding of names;
  3355 
  3356 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  3357 XSYMBOL_HOME; no longer need to do manual configuration in most
  3358 situations;
  3359 
  3360 * system: compression of ML heaps images may now be controlled via -c
  3361 option of isabelle and isatool usedir (currently only observed by
  3362 Poly/ML);
  3363 
  3364 * system: isatool installfonts may handle X-Symbol fonts as well (very
  3365 useful for remote X11);
  3366 
  3367 * system: provide TAGS file for Isabelle sources;
  3368 
  3369 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  3370 order;
  3371 
  3372 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  3373 timing flag supersedes proof_timing and Toplevel.trace;
  3374 
  3375 * ML: new combinators |>> and |>>> for incremental transformations
  3376 with secondary results (e.g. certain theory extensions):
  3377 
  3378 * ML: PureThy.add_defs gets additional argument to indicate potential
  3379 overloading (usually false);
  3380 
  3381 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  3382 results;
  3383 
  3384 
  3385 
  3386 New in Isabelle99 (October 1999)
  3387 --------------------------------
  3388 
  3389 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3390 
  3391 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  3392 are no longer simplified.  (This allows the simplifier to unfold recursive
  3393 functional programs.)  To restore the old behaviour, declare
  3394 
  3395     Delcongs [if_weak_cong];
  3396 
  3397 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  3398 complement;
  3399 
  3400 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  3401 
  3402 * HOL/datatype: mutual_induct_tac no longer exists --
  3403   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  3404 
  3405 * HOL/typedef: fixed type inference for representing set; type
  3406 arguments now have to occur explicitly on the rhs as type constraints;
  3407 
  3408 * ZF: The con_defs part of an inductive definition may no longer refer
  3409 to constants declared in the same theory;
  3410 
  3411 * HOL, ZF: the function mk_cases, generated by the inductive
  3412 definition package, has lost an argument.  To simplify its result, it
  3413 uses the default simpset instead of a supplied list of theorems.
  3414 
  3415 * HOL/List: the constructors of type list are now Nil and Cons;
  3416 
  3417 * Simplifier: the type of the infix ML functions
  3418         setSSolver addSSolver setSolver addSolver
  3419 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  3420 for packaging solvers. A solver is created via
  3421         mk_solver: string -> (thm list -> int -> tactic) -> solver
  3422 where the string argument is only a comment.
  3423 
  3424 
  3425 *** Proof tools ***
  3426 
  3427 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  3428 decision procedure for linear arithmetic. Currently it is used for
  3429 types `nat', `int', and `real' in HOL (see below); it can, should and
  3430 will be instantiated for other types and logics as well.
  3431 
  3432 * The simplifier now accepts rewrite rules with flexible heads, eg
  3433      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  3434   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  3435   matching.
  3436 
  3437 
  3438 *** General ***
  3439 
  3440 * New Isabelle/Isar subsystem provides an alternative to traditional
  3441 tactical theorem proving; together with the ProofGeneral/isar user
  3442 interface it offers an interactive environment for developing human
  3443 readable proof documents (Isar == Intelligible semi-automated
  3444 reasoning); for further information see isatool doc isar-ref,
  3445 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  3446 
  3447 * improved and simplified presentation of theories: better HTML markup
  3448 (including colors), graph views in several sizes; isatool usedir now
  3449 provides a proper interface for user theories (via -P option); actual
  3450 document preparation based on (PDF)LaTeX is available as well (for
  3451 new-style theories only); see isatool doc system for more information;
  3452 
  3453 * native support for Proof General, both for classic Isabelle and
  3454 Isabelle/Isar;
  3455 
  3456 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  3457 using the graph browser tool;
  3458 
  3459 * Isabelle manuals now also available as PDF;
  3460 
  3461 * theory loader rewritten from scratch (may not be fully
  3462 bug-compatible); old loadpath variable has been replaced by show_path,
  3463 add_path, del_path, reset_path functions; new operations such as
  3464 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  3465 isatool doc ref);
  3466 
  3467 * improved isatool install: option -k creates KDE application icon,
  3468 option -p DIR installs standalone binaries;
  3469 
  3470 * added ML_PLATFORM setting (useful for cross-platform installations);
  3471 more robust handling of platform specific ML images for SML/NJ;
  3472 
  3473 * the settings environment is now statically scoped, i.e. it is never
  3474 created again in sub-processes invoked from isabelle, isatool, or
  3475 Isabelle;
  3476 
  3477 * path element specification '~~' refers to '$ISABELLE_HOME';
  3478 
  3479 * in locales, the "assumes" and "defines" parts may be omitted if
  3480 empty;
  3481 
  3482 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  3483 long arrows);
  3484 
  3485 * new print_mode "HTML";
  3486 
  3487 * new flag show_tags controls display of tags of theorems (which are
  3488 basically just comments that may be attached by some tools);
  3489 
  3490 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  3491 mode and goal output format:
  3492 
  3493 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  3494 244c244
  3495 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  3496 ---
  3497 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  3498 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  3499 181c181
  3500 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  3501 ---
  3502 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  3503 
  3504 * function bind_thms stores lists of theorems (cf. bind_thm);
  3505 
  3506 * new shorthand tactics ftac, eatac, datac, fatac;
  3507 
  3508 * qed (and friends) now accept "" as result name; in that case the
  3509 theorem is not stored, but proper checks and presentation of the
  3510 result still apply;
  3511 
  3512 * theorem database now also indexes constants "Trueprop", "all",
  3513 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  3514 
  3515 
  3516 *** HOL ***
  3517 
  3518 ** HOL arithmetic **
  3519 
  3520 * There are now decision procedures for linear arithmetic over nat and
  3521 int:
  3522 
  3523 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  3524 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  3525 are treated as atomic; subformulae not involving type `nat' or `int'
  3526 are ignored; quantified subformulae are ignored unless they are
  3527 positive universal or negative existential. The tactic has to be
  3528 invoked by hand and can be a little bit slow. In particular, the
  3529 running time is exponential in the number of occurrences of `min' and
  3530 `max', and `-' on `nat'.
  3531 
  3532 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  3533 (negated) (in)equalities among the premises and the conclusion into
  3534 account (i.e. no compound formulae) and does not know about `min' and
  3535 `max', and `-' on `nat'. It is fast and is used automatically by the
  3536 simplifier.
  3537 
  3538 NB: At the moment, these decision procedures do not cope with mixed
  3539 nat/int formulae where the two parts interact, such as `m < n ==>
  3540 int(m) < int(n)'.
  3541 
  3542 * HOL/Numeral provides a generic theory of numerals (encoded
  3543 efficiently as bit strings); setup for types nat/int/real is in place;
  3544 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  3545 int, existing theories and proof scripts may require a few additional
  3546 type constraints;
  3547 
  3548 * integer division and remainder can now be performed on constant
  3549 arguments;
  3550 
  3551 * many properties of integer multiplication, division and remainder
  3552 are now available;
  3553 
  3554 * An interface to the Stanford Validity Checker (SVC) is available through the
  3555 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  3556 are proved automatically.  SVC must be installed separately, and its results
  3557 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  3558 invocation of the underlying oracle).  For SVC see
  3559   http://verify.stanford.edu/SVC
  3560 
  3561 * IsaMakefile: the HOL-Real target now builds an actual image;
  3562 
  3563 
  3564 ** HOL misc **
  3565 
  3566 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  3567 (in Isabelle/Isar) -- by Gertrud Bauer;
  3568 
  3569 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  3570 analysis for assembly languages with subtypes;
  3571 
  3572 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  3573 -- avoids syntactic ambiguities and treats state, transition, and
  3574 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  3575 changed syntax and (many) tactics;
  3576 
  3577 * HOL/inductive: Now also handles more general introduction rules such
  3578   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  3579   theorems are now maintained within the theory (maintained via the
  3580   "mono" attribute);
  3581 
  3582 * HOL/datatype: Now also handles arbitrarily branching datatypes
  3583   (using function types) such as
  3584 
  3585   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  3586 
  3587 * HOL/record: record_simproc (part of the default simpset) takes care
  3588 of selectors applied to updated records; record_split_tac is no longer
  3589 part of the default claset; update_defs may now be removed from the
  3590 simpset in many cases; COMPATIBILITY: old behavior achieved by
  3591 
  3592   claset_ref () := claset() addSWrapper record_split_wrapper;
  3593   Delsimprocs [record_simproc]
  3594 
  3595 * HOL/typedef: fixed type inference for representing set; type
  3596 arguments now have to occur explicitly on the rhs as type constraints;
  3597 
  3598 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  3599 names rather than an ML expression;
  3600 
  3601 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  3602 supplied later.  Program schemes can be defined, such as
  3603     "While B C s = (if B s then While B C (C s) else s)"
  3604 where the well-founded relation can be chosen after B and C have been given.
  3605 
  3606 * HOL/List: the constructors of type list are now Nil and Cons;
  3607 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  3608 course, ML tools referring to List.list.op # etc. have to be adapted;
  3609 
  3610 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  3611 disabled by default; run isabelle with option -m HOL to get back to
  3612 the original Gordon/HOL-style output;
  3613 
  3614 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  3615 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  3616 
  3617 * HOL basic syntax simplified (more orthogonal): all variants of
  3618 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  3619 Eps operator is provided as well: "SOME x. P[x]";
  3620 
  3621 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  3622 
  3623 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  3624 thus available for user theories;
  3625 
  3626 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  3627 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  3628 time;
  3629 
  3630 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  3631 several times and then mp;
  3632 
  3633 
  3634 *** LK ***
  3635 
  3636 * the notation <<...>> is now available as a notation for sequences of
  3637 formulas;
  3638 
  3639 * the simplifier is now installed
  3640 
  3641 * the axiom system has been generalized (thanks to Soren Heilmann)
  3642 
  3643 * the classical reasoner now has a default rule database
  3644 
  3645 
  3646 *** ZF ***
  3647 
  3648 * new primrec section allows primitive recursive functions to be given
  3649 directly (as in HOL) over datatypes and the natural numbers;
  3650 
  3651 * new tactics induct_tac and exhaust_tac for induction (or case
  3652 analysis) over datatypes and the natural numbers;
  3653 
  3654 * the datatype declaration of type T now defines the recursor T_rec;
  3655 
  3656 * simplification automatically does freeness reasoning for datatype
  3657 constructors;
  3658 
  3659 * automatic type-inference, with AddTCs command to insert new
  3660 type-checking rules;
  3661 
  3662 * datatype introduction rules are now added as Safe Introduction rules
  3663 to the claset;
  3664 
  3665 * the syntax "if P then x else y" is now available in addition to
  3666 if(P,x,y);
  3667 
  3668 
  3669 *** Internal programming interfaces ***
  3670 
  3671 * tuned simplifier trace output; new flag debug_simp;
  3672 
  3673 * structures Vartab / Termtab (instances of TableFun) offer efficient
  3674 tables indexed by indexname_ord / term_ord (compatible with aconv);
  3675 
  3676 * AxClass.axclass_tac lost the theory argument;
  3677 
  3678 * tuned current_goals_markers semantics: begin / end goal avoids
  3679 printing empty lines;
  3680 
  3681 * removed prs and prs_fn hook, which was broken because it did not
  3682 include \n in its semantics, forcing writeln to add one
  3683 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  3684 string -> unit if you really want to output text without newline;
  3685 
  3686 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  3687 plain output, interface builders may have to enable 'isabelle_font'
  3688 mode to get Isabelle font glyphs as before;
  3689 
  3690 * refined token_translation interface; INCOMPATIBILITY: output length
  3691 now of type real instead of int;
  3692 
  3693 * theory loader actions may be traced via new ThyInfo.add_hook
  3694 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  3695 your own database of information attached to *whole* theories -- as
  3696 opposed to intra-theory data slots offered via TheoryDataFun;
  3697 
  3698 * proper handling of dangling sort hypotheses (at last!);
  3699 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  3700 extra sort hypotheses that can be witnessed from the type signature;
  3701 the force_strip_shyps flag is gone, any remaining shyps are simply
  3702 left in the theorem (with a warning issued by strip_shyps_warning);
  3703 
  3704 
  3705 
  3706 New in Isabelle98-1 (October 1998)
  3707 ----------------------------------
  3708 
  3709 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3710 
  3711 * several changes of automated proof tools;
  3712 
  3713 * HOL: major changes to the inductive and datatype packages, including
  3714 some minor incompatibilities of theory syntax;
  3715 
  3716 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  3717 called `inj_on';
  3718 
  3719 * HOL: removed duplicate thms in Arith:
  3720   less_imp_add_less  should be replaced by  trans_less_add1
  3721   le_imp_add_le      should be replaced by  trans_le_add1
  3722 
  3723 * HOL: unary minus is now overloaded (new type constraints may be
  3724 required);
  3725 
  3726 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  3727 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  3728 now taken as an integer constant.
  3729 
  3730 * Pure: ML function 'theory_of' renamed to 'theory';
  3731 
  3732 
  3733 *** Proof tools ***
  3734 
  3735 * Simplifier:
  3736   1. Asm_full_simp_tac is now more aggressive.
  3737      1. It will sometimes reorient premises if that increases their power to
  3738         simplify.
  3739      2. It does no longer proceed strictly from left to right but may also
  3740         rotate premises to achieve further simplification.
  3741      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  3742      old Asm_full_simp_tac in that it does not rotate premises.
  3743   2. The simplifier now knows a little bit about nat-arithmetic.
  3744 
  3745 * Classical reasoner: wrapper mechanism for the classical reasoner now
  3746 allows for selected deletion of wrappers, by introduction of names for
  3747 wrapper functionals.  This implies that addbefore, addSbefore,
  3748 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  3749 and that adding two tactics with the same name overwrites the first
  3750 one (emitting a warning).
  3751   type wrapper = (int -> tactic) -> (int -> tactic)
  3752   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  3753   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  3754   delWrapper, delSWrapper: claset *  string            -> claset
  3755   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  3756 
  3757 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  3758 semantics; addbefore now affects only the unsafe part of step_tac
  3759 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  3760 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  3761 by Force_tac;
  3762 
  3763 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  3764 compWrapper; added safe wrapper (and access functions for it);
  3765 
  3766 * HOL/split_all_tac is now much faster and fails if there is nothing
  3767 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  3768 and the names of the automatically generated variables have changed.
  3769 split_all_tac has moved within claset() from unsafe wrappers to safe
  3770 wrappers, which means that !!-bound variables are split much more
  3771 aggressively, and safe_tac and clarify_tac now split such variables.
  3772 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  3773 Note: the same holds for record_split_tac, which does the job of
  3774 split_all_tac for record fields.
  3775 
  3776 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  3777 permanently to the default simpset using Addsplits just like
  3778 Addsimps. They can be removed via Delsplits just like
  3779 Delsimps. Lower-case versions are also available.
  3780 
  3781 * HOL/Simplifier: The rule split_if is now part of the default
  3782 simpset. This means that the simplifier will eliminate all occurrences
  3783 of if-then-else in the conclusion of a goal. To prevent this, you can
  3784 either remove split_if completely from the default simpset by
  3785 `Delsplits [split_if]' or remove it in a specific call of the
  3786 simplifier using `... delsplits [split_if]'.  You can also add/delete
  3787 other case splitting rules to/from the default simpset: every datatype
  3788 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  3789 t is the name of the datatype).
  3790 
  3791 * Classical reasoner / Simplifier combination: new force_tac (and
  3792 derivatives Force_tac, force) combines rewriting and classical
  3793 reasoning (and whatever other tools) similarly to auto_tac, but is
  3794 aimed to solve the given subgoal completely.
  3795 
  3796 
  3797 *** General ***
  3798 
  3799 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  3800 and `goalw': the theory is no longer needed as an explicit argument -
  3801 the current theory context is used; assumptions are no longer returned
  3802 at the ML-level unless one of them starts with ==> or !!; it is
  3803 recommended to convert to these new commands using isatool fixgoal
  3804 (backup your sources first!);
  3805 
  3806 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  3807 the current theory context, and 'theory' to lookup stored theories;
  3808 
  3809 * new theory section 'locale' for declaring constants, assumptions and
  3810 definitions that have local scope;
  3811 
  3812 * new theory section 'nonterminals' for purely syntactic types;
  3813 
  3814 * new theory section 'setup' for generic ML setup functions
  3815 (e.g. package initialization);
  3816 
  3817 * the distribution now includes Isabelle icons: see
  3818 lib/logo/isabelle-{small,tiny}.xpm;
  3819 
  3820 * isatool install - install binaries with absolute references to
  3821 ISABELLE_HOME/bin;
  3822 
  3823 * isatool logo -- create instances of the Isabelle logo (as EPS);
  3824 
  3825 * print mode 'emacs' reserved for Isamode;
  3826 
  3827 * support multiple print (ast) translations per constant name;
  3828 
  3829 * theorems involving oracles are now printed with a suffixed [!];
  3830 
  3831 
  3832 *** HOL ***
  3833 
  3834 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  3835 
  3836 * HOL/inductive package reorganized and improved: now supports mutual
  3837 definitions such as
  3838 
  3839   inductive EVEN ODD
  3840     intrs
  3841       null "0 : EVEN"
  3842       oddI "n : EVEN ==> Suc n : ODD"
  3843       evenI "n : ODD ==> Suc n : EVEN"
  3844 
  3845 new theorem list "elims" contains an elimination rule for each of the
  3846 recursive sets; inductive definitions now handle disjunctive premises
  3847 correctly (also ZF);
  3848 
  3849 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  3850 "mutual_induct" no longer exists - the induction rule is always
  3851 contained in "induct";
  3852 
  3853 
  3854 * HOL/datatype package re-implemented and greatly improved: now
  3855 supports mutually recursive datatypes such as
  3856 
  3857   datatype
  3858     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  3859             | SUM ('a aexp) ('a aexp)
  3860             | DIFF ('a aexp) ('a aexp)
  3861             | NUM 'a
  3862   and
  3863     'a bexp = LESS ('a aexp) ('a aexp)
  3864             | AND ('a bexp) ('a bexp)
  3865             | OR ('a bexp) ('a bexp)
  3866 
  3867 as well as indirectly recursive datatypes such as
  3868 
  3869   datatype
  3870     ('a, 'b) term = Var 'a
  3871                   | App 'b ((('a, 'b) term) list)
  3872 
  3873 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  3874 induction on mutually / indirectly recursive datatypes.
  3875 
  3876 Primrec equations are now stored in theory and can be accessed via
  3877 <function_name>.simps.
  3878 
  3879 INCOMPATIBILITIES:
  3880 
  3881   - Theories using datatypes must now have theory Datatype as an
  3882     ancestor.
  3883   - The specific <typename>.induct_tac no longer exists - use the
  3884     generic induct_tac instead.
  3885   - natE has been renamed to nat.exhaust - use exhaust_tac
  3886     instead of res_inst_tac ... natE. Note that the variable
  3887     names in nat.exhaust differ from the names in natE, this
  3888     may cause some "fragile" proofs to fail.
  3889   - The theorems split_<typename>_case and split_<typename>_case_asm
  3890     have been renamed to <typename>.split and <typename>.split_asm.
  3891   - Since default sorts of type variables are now handled correctly,
  3892     some datatype definitions may have to be annotated with explicit
  3893     sort constraints.
  3894   - Primrec definitions no longer require function name and type
  3895     of recursive argument.
  3896 
  3897 Consider using isatool fixdatatype to adapt your theories and proof
  3898 scripts to the new package (backup your sources first!).
  3899 
  3900 
  3901 * HOL/record package: considerably improved implementation; now
  3902 includes concrete syntax for record types, terms, updates; theorems
  3903 for surjective pairing and splitting !!-bound record variables; proof
  3904 support is as follows:
  3905 
  3906   1) standard conversions (selectors or updates applied to record
  3907 constructor terms) are part of the standard simpset;
  3908 
  3909   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  3910 made part of standard simpset and claset via addIffs;
  3911 
  3912   3) a tactic for record field splitting (record_split_tac) is part of
  3913 the standard claset (addSWrapper);
  3914 
  3915 To get a better idea about these rules you may retrieve them via
  3916 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  3917 the name of your record type.
  3918 
  3919 The split tactic 3) conceptually simplifies by the following rule:
  3920 
  3921   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  3922 
  3923 Thus any record variable that is bound by meta-all will automatically
  3924 blow up into some record constructor term, consequently the
  3925 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  3926 solve record problems automatically.
  3927 
  3928 
  3929 * reorganized the main HOL image: HOL/Integ and String loaded by
  3930 default; theory Main includes everything;
  3931 
  3932 * automatic simplification of integer sums and comparisons, using cancellation;
  3933 
  3934 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  3935 
  3936 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  3937 
  3938 * many new identities for unions, intersections, set difference, etc.;
  3939 
  3940 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  3941 called split_if, split_split, split_sum_case and split_nat_case (to go
  3942 with add/delsplits);
  3943 
  3944 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  3945 (?x::unit) = (); this is made part of the default simpset, which COULD
  3946 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  3947 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  3948 unit_abs_eta_conv is added in order to counter the effect of
  3949 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  3950 %u.f();
  3951 
  3952 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  3953 makes more sense);
  3954 
  3955 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  3956   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  3957   disjointness reasoning but breaking a few old proofs.
  3958 
  3959 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  3960 to 'converse' from 'inverse' (for compatibility with ZF and some
  3961 literature);
  3962 
  3963 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  3964 the well-founded relation;
  3965 
  3966 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  3967     Compl A.  The "Compl" syntax remains available as input syntax for this
  3968     release ONLY.
  3969 
  3970 * HOL/Update: new theory of function updates:
  3971     f(a:=b) == %x. if x=a then b else f x
  3972 may also be iterated as in f(a:=b,c:=d,...);
  3973 
  3974 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  3975 
  3976 * HOL/List:
  3977   - new function list_update written xs[i:=v] that updates the i-th
  3978     list position. May also be iterated as in xs[i:=a,j:=b,...].
  3979   - new function `upt' written [i..j(] which generates the list
  3980     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  3981     bound write [i..j], which is a shorthand for [i..j+1(].
  3982   - new lexicographic orderings and corresponding wellfoundedness theorems.
  3983 
  3984 * HOL/Arith:
  3985   - removed 'pred' (predecessor) function;
  3986   - generalized some theorems about n-1;
  3987   - many new laws about "div" and "mod";
  3988   - new laws about greatest common divisors (see theory ex/Primes);
  3989 
  3990 * HOL/Relation: renamed the relational operator r^-1 "converse"
  3991 instead of "inverse";
  3992 
  3993 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  3994   of the multiset ordering;
  3995 
  3996 * directory HOL/Real: a construction of the reals using Dedekind cuts
  3997   (not included by default);
  3998 
  3999 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  4000 
  4001 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  4002   programs, i.e. different program variables may have different types.
  4003 
  4004 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4005   [previously, this check worked only if the rewrite rule was unconditional]
  4006   Now rew can involve either definitions or equalities (either == or =).
  4007 
  4008 
  4009 *** ZF ***
  4010 
  4011 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  4012   only the theorems proved on ZF.ML;
  4013 
  4014 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4015   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4016   disjointness reasoning but breaking a few old proofs.
  4017 
  4018 * ZF/Update: new theory of function updates
  4019     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  4020   may also be iterated as in f(a:=b,c:=d,...);
  4021 
  4022 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  4023 
  4024 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4025   [previously, this check worked only if the rewrite rule was unconditional]
  4026   Now rew can involve either definitions or equalities (either == or =).
  4027 
  4028 * case_tac provided for compatibility with HOL
  4029     (like the old excluded_middle_tac, but with subgoals swapped)
  4030 
  4031 
  4032 *** Internal programming interfaces ***
  4033 
  4034 * Pure: several new basic modules made available for general use, see
  4035 also src/Pure/README;
  4036 
  4037 * improved the theory data mechanism to support encapsulation (data
  4038 kind name replaced by private Object.kind, acting as authorization
  4039 key); new type-safe user interface via functor TheoryDataFun; generic
  4040 print_data function becomes basically useless;
  4041 
  4042 * removed global_names compatibility flag -- all theory declarations
  4043 are qualified by default;
  4044 
  4045 * module Pure/Syntax now offers quote / antiquote translation
  4046 functions (useful for Hoare logic etc. with implicit dependencies);
  4047 see HOL/ex/Antiquote for an example use;
  4048 
  4049 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  4050 cterm -> thm;
  4051 
  4052 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  4053 subgoal;
  4054 
  4055 * Display.print_goals function moved to Locale.print_goals;
  4056 
  4057 * standard print function for goals supports current_goals_markers
  4058 variable for marking begin of proof, end of proof, start of goal; the
  4059 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  4060 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  4061 for example;
  4062 
  4063 
  4064 
  4065 New in Isabelle98 (January 1998)
  4066 --------------------------------
  4067 
  4068 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4069 
  4070 * changed lexical syntax of terms / types: dots made part of long
  4071 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  4072 
  4073 * simpset (and claset) reference variable replaced by functions
  4074 simpset / simpset_ref;
  4075 
  4076 * no longer supports theory aliases (via merge) and non-trivial
  4077 implicit merge of thms' signatures;
  4078 
  4079 * most internal names of constants changed due to qualified names;
  4080 
  4081 * changed Pure/Sequence interface (see Pure/seq.ML);
  4082 
  4083 
  4084 *** General Changes ***
  4085 
  4086 * hierachically structured name spaces (for consts, types, axms, thms
  4087 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  4088 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  4089 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  4090 long_names for fully qualified output names; NOTE: ML programs
  4091 (special tactics, packages etc.) referring to internal names may have
  4092 to be adapted to cope with fully qualified names; in case of severe
  4093 backward campatibility problems try setting 'global_names' at compile
  4094 time to have enrything declared within a flat name space; one may also
  4095 fine tune name declarations in theories via the 'global' and 'local'
  4096 section;
  4097 
  4098 * reimplemented the implicit simpset and claset using the new anytype
  4099 data filed in signatures; references simpset:simpset ref etc. are
  4100 replaced by functions simpset:unit->simpset and
  4101 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  4102 to patch your ML files accordingly;
  4103 
  4104 * HTML output now includes theory graph data for display with Java
  4105 applet or isatool browser; data generated automatically via isatool
  4106 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  4107 
  4108 * defs may now be conditional; improved rewrite_goals_tac to handle
  4109 conditional equations;
  4110 
  4111 * defs now admits additional type arguments, using TYPE('a) syntax;
  4112 
  4113 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  4114 creates a new theory node; implicit merge of thms' signatures is
  4115 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  4116 transfer:theory->thm->thm in (rare) cases;
  4117 
  4118 * improved handling of draft signatures / theories; draft thms (and
  4119 ctyps, cterms) are automatically promoted to real ones;
  4120 
  4121 * slightly changed interfaces for oracles: admit many per theory, named
  4122 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  4123 
  4124 * print_goals: optional output of const types (set show_consts and
  4125 show_types);
  4126 
  4127 * improved output of warnings (###) and errors (***);
  4128 
  4129 * subgoal_tac displays a warning if the new subgoal has type variables;
  4130 
  4131 * removed old README and Makefiles;
  4132 
  4133 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  4134 
  4135 * removed obsolete init_pps and init_database;
  4136 
  4137 * deleted the obsolete tactical STATE, which was declared by
  4138     fun STATE tacfun st = tacfun st st;
  4139 
  4140 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  4141 (which abbreviates $HOME);
  4142 
  4143 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  4144 use isatool fixseq to adapt your ML programs (this works for fully
  4145 qualified references to the Sequence structure only!);
  4146 
  4147 * use_thy no longer requires writable current directory; it always
  4148 reloads .ML *and* .thy file, if either one is out of date;
  4149 
  4150 
  4151 *** Classical Reasoner ***
  4152 
  4153 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  4154 tactics that use classical reasoning to simplify a subgoal without
  4155 splitting it into several subgoals;
  4156 
  4157 * Safe_tac: like safe_tac but uses the default claset;
  4158 
  4159 
  4160 *** Simplifier ***
  4161 
  4162 * added simplification meta rules:
  4163     (asm_)(full_)simplify: simpset -> thm -> thm;
  4164 
  4165 * simplifier.ML no longer part of Pure -- has to be loaded by object
  4166 logics (again);
  4167 
  4168 * added prems argument to simplification procedures;
  4169 
  4170 * HOL, FOL, ZF: added infix function `addsplits':
  4171   instead of `<simpset> setloop (split_tac <thms>)'
  4172   you can simply write `<simpset> addsplits <thms>'
  4173 
  4174 
  4175 *** Syntax ***
  4176 
  4177 * TYPE('a) syntax for type reflection terms;
  4178 
  4179 * no longer handles consts with name "" -- declare as 'syntax' instead;
  4180 
  4181 * pretty printer: changed order of mixfix annotation preference (again!);
  4182 
  4183 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  4184 
  4185 
  4186 *** HOL ***
  4187 
  4188 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4189   with `addloop' of the simplifier to faciliate case splitting in premises.
  4190 
  4191 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  4192 
  4193 * HOL/Auth: new protocol proofs including some for the Internet
  4194   protocol TLS;
  4195 
  4196 * HOL/Map: new theory of `maps' a la VDM;
  4197 
  4198 * HOL/simplifier: simplification procedures nat_cancel_sums for
  4199 cancelling out common nat summands from =, <, <= (in)equalities, or
  4200 differences; simplification procedures nat_cancel_factor for
  4201 cancelling common factor from =, <, <= (in)equalities over natural
  4202 sums; nat_cancel contains both kinds of procedures, it is installed by
  4203 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  4204 
  4205 * HOL/simplifier: terms of the form
  4206   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  4207   are rewritten to
  4208   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  4209   and those of the form
  4210   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  4211   are rewritten to
  4212   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  4213 
  4214 * HOL/datatype
  4215   Each datatype `t' now comes with a theorem `split_t_case' of the form
  4216 
  4217   P(t_case f1 ... fn x) =
  4218      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  4219         ...
  4220        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  4221      )
  4222 
  4223   and a theorem `split_t_case_asm' of the form
  4224 
  4225   P(t_case f1 ... fn x) =
  4226     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  4227         ...
  4228        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  4229      )
  4230   which can be added to a simpset via `addsplits'. The existing theorems
  4231   expand_list_case and expand_option_case have been renamed to
  4232   split_list_case and split_option_case.
  4233 
  4234 * HOL/Arithmetic:
  4235   - `pred n' is automatically converted to `n-1'.
  4236     Users are strongly encouraged not to use `pred' any longer,
  4237     because it will disappear altogether at some point.
  4238   - Users are strongly encouraged to write "0 < n" rather than
  4239     "n ~= 0". Theorems and proof tools have been modified towards this
  4240     `standard'.
  4241 
  4242 * HOL/Lists:
  4243   the function "set_of_list" has been renamed "set" (and its theorems too);
  4244   the function "nth" now takes its arguments in the reverse order and
  4245   has acquired the infix notation "!" as in "xs!n".
  4246 
  4247 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  4248 
  4249 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  4250   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  4251 
  4252 * HOL/record: extensible records with schematic structural subtyping
  4253 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  4254 still lacks various theorems and concrete record syntax;
  4255 
  4256 
  4257 *** HOLCF ***
  4258 
  4259 * removed "axioms" and "generated by" sections;
  4260 
  4261 * replaced "ops" section by extended "consts" section, which is capable of
  4262   handling the continuous function space "->" directly;
  4263 
  4264 * domain package:
  4265   . proves theorems immediately and stores them in the theory,
  4266   . creates hierachical name space,
  4267   . now uses normal mixfix annotations (instead of cinfix...),
  4268   . minor changes to some names and values (for consistency),
  4269   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  4270   . separator between mutual domain defs: changed "," to "and",
  4271   . improved handling of sort constraints;  now they have to
  4272     appear on the left-hand side of the equations only;
  4273 
  4274 * fixed LAM <x,y,zs>.b syntax;
  4275 
  4276 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  4277 adm (%x. P (t x)), where P is chainfinite and t continuous;
  4278 
  4279 
  4280 *** FOL and ZF ***
  4281 
  4282 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4283   with `addloop' of the simplifier to faciliate case splitting in premises.
  4284 
  4285 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  4286 in HOL, they strip ALL and --> from proved theorems;
  4287 
  4288 
  4289 
  4290 New in Isabelle94-8 (May 1997)
  4291 ------------------------------
  4292 
  4293 *** General Changes ***
  4294 
  4295 * new utilities to build / run / maintain Isabelle etc. (in parts
  4296 still somewhat experimental); old Makefiles etc. still functional;
  4297 
  4298 * new 'Isabelle System Manual';
  4299 
  4300 * INSTALL text, together with ./configure and ./build scripts;
  4301 
  4302 * reimplemented type inference for greater efficiency, better error
  4303 messages and clean internal interface;
  4304 
  4305 * prlim command for dealing with lots of subgoals (an easier way of
  4306 setting goals_limit);
  4307 
  4308 
  4309 *** Syntax ***
  4310 
  4311 * supports alternative (named) syntax tables (parser and pretty
  4312 printer); internal interface is provided by add_modesyntax(_i);
  4313 
  4314 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  4315 be used in conjunction with the Isabelle symbol font; uses the
  4316 "symbols" syntax table;
  4317 
  4318 * added token_translation interface (may translate name tokens in
  4319 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  4320 the current print_mode); IMPORTANT: user print translation functions
  4321 are responsible for marking newly introduced bounds
  4322 (Syntax.mark_boundT);
  4323 
  4324 * token translations for modes "xterm" and "xterm_color" that display
  4325 names in bold, underline etc. or colors (which requires a color
  4326 version of xterm);
  4327 
  4328 * infixes may now be declared with names independent of their syntax;
  4329 
  4330 * added typed_print_translation (like print_translation, but may
  4331 access type of constant);
  4332 
  4333 
  4334 *** Classical Reasoner ***
  4335 
  4336 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  4337 some limitations.  Blast_tac...
  4338   + ignores addss, addbefore, addafter; this restriction is intrinsic
  4339   + ignores elimination rules that don't have the correct format
  4340         (the conclusion MUST be a formula variable)
  4341   + ignores types, which can make HOL proofs fail
  4342   + rules must not require higher-order unification, e.g. apply_type in ZF
  4343     [message "Function Var's argument not a bound variable" relates to this]
  4344   + its proof strategy is more general but can actually be slower
  4345 
  4346 * substitution with equality assumptions no longer permutes other
  4347 assumptions;
  4348 
  4349 * minor changes in semantics of addafter (now called addaltern); renamed
  4350 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  4351 (and access functions for it);
  4352 
  4353 * improved combination of classical reasoner and simplifier:
  4354   + functions for handling clasimpsets
  4355   + improvement of addss: now the simplifier is called _after_ the
  4356     safe steps.
  4357   + safe variant of addss called addSss: uses safe simplifications
  4358     _during_ the safe steps. It is more complete as it allows multiple
  4359     instantiations of unknowns (e.g. with slow_tac).
  4360 
  4361 *** Simplifier ***
  4362 
  4363 * added interface for simplification procedures (functions that
  4364 produce *proven* rewrite rules on the fly, depending on current
  4365 redex);
  4366 
  4367 * ordering on terms as parameter (used for ordered rewriting);
  4368 
  4369 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  4370 
  4371 * the solver is now split into a safe and an unsafe part.
  4372 This should be invisible for the normal user, except that the
  4373 functions setsolver and addsolver have been renamed to setSolver and
  4374 addSolver; added safe_asm_full_simp_tac;
  4375 
  4376 
  4377 *** HOL ***
  4378 
  4379 * a generic induction tactic `induct_tac' which works for all datatypes and
  4380 also for type `nat';
  4381 
  4382 * a generic case distinction tactic `exhaust_tac' which works for all
  4383 datatypes and also for type `nat';
  4384 
  4385 * each datatype comes with a function `size';
  4386 
  4387 * patterns in case expressions allow tuple patterns as arguments to
  4388 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  4389 
  4390 * primrec now also works with type nat;
  4391 
  4392 * recdef: a new declaration form, allows general recursive functions to be
  4393 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  4394 
  4395 * the constant for negation has been renamed from "not" to "Not" to
  4396 harmonize with FOL, ZF, LK, etc.;
  4397 
  4398 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  4399 infinite lists;
  4400 
  4401 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  4402 
  4403 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  4404 problems in commutative rings, using axiomatic type classes for + and *;
  4405 
  4406 * more examples in HOL/MiniML and HOL/Auth;
  4407 
  4408 * more default rewrite rules for quantifiers, union/intersection;
  4409 
  4410 * a new constant `arbitrary == @x.False';
  4411 
  4412 * HOLCF/IOA replaces old HOL/IOA;
  4413 
  4414 * HOLCF changes: derived all rules and arities
  4415   + axiomatic type classes instead of classes
  4416   + typedef instead of faking type definitions
  4417   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  4418   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  4419   + eliminated the types void, one, tr
  4420   + use unit lift and bool lift (with translations) instead of one and tr
  4421   + eliminated blift from Lift3.thy (use Def instead of blift)
  4422   all eliminated rules are derived as theorems --> no visible changes ;
  4423 
  4424 
  4425 *** ZF ***
  4426 
  4427 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  4428 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  4429 as ZF_cs addSIs [equalityI];
  4430 
  4431 
  4432 
  4433 New in Isabelle94-7 (November 96)
  4434 ---------------------------------
  4435 
  4436 * allowing negative levels (as offsets) in prlev and choplev;
  4437 
  4438 * super-linear speedup for large simplifications;
  4439 
  4440 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  4441 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  4442 FAIL); can suppress it using the command Delsimps (ex_simps @
  4443 all_simps); De Morgan laws are also now included, by default;
  4444 
  4445 * improved printing of ==>  :  ~:
  4446 
  4447 * new object-logic "Sequents" adds linear logic, while replacing LK
  4448 and Modal (thanks to Sara Kalvala);
  4449 
  4450 * HOL/Auth: correctness proofs for authentication protocols;
  4451 
  4452 * HOL: new auto_tac combines rewriting and classical reasoning (many
  4453 examples on HOL/Auth);
  4454 
  4455 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  4456 the rewriter and classical reasoner simultaneously;
  4457 
  4458 * function uresult no longer returns theorems in "standard" format;
  4459 regain previous version by: val uresult = standard o uresult;
  4460 
  4461 
  4462 
  4463 New in Isabelle94-6
  4464 -------------------
  4465 
  4466 * oracles -- these establish an interface between Isabelle and trusted
  4467 external reasoners, which may deliver results as theorems;
  4468 
  4469 * proof objects (in particular record all uses of oracles);
  4470 
  4471 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  4472 
  4473 * "constdefs" section in theory files;
  4474 
  4475 * "primrec" section (HOL) no longer requires names;
  4476 
  4477 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  4478 
  4479 
  4480 
  4481 New in Isabelle94-5
  4482 -------------------
  4483 
  4484 * reduced space requirements;
  4485 
  4486 * automatic HTML generation from theories;
  4487 
  4488 * theory files no longer require "..." (quotes) around most types;
  4489 
  4490 * new examples, including two proofs of the Church-Rosser theorem;
  4491 
  4492 * non-curried (1994) version of HOL is no longer distributed;
  4493 
  4494 
  4495 
  4496 New in Isabelle94-4
  4497 -------------------
  4498 
  4499 * greatly reduced space requirements;
  4500 
  4501 * theory files (.thy) no longer require \...\ escapes at line breaks;
  4502 
  4503 * searchable theorem database (see the section "Retrieving theorems" on
  4504 page 8 of the Reference Manual);
  4505 
  4506 * new examples, including Grabczewski's monumental case study of the
  4507 Axiom of Choice;
  4508 
  4509 * The previous version of HOL renamed to Old_HOL;
  4510 
  4511 * The new version of HOL (previously called CHOL) uses a curried syntax
  4512 for functions.  Application looks like f a b instead of f(a,b);
  4513 
  4514 * Mutually recursive inductive definitions finally work in HOL;
  4515 
  4516 * In ZF, pattern-matching on tuples is now available in all abstractions and
  4517 translates to the operator "split";
  4518 
  4519 
  4520 
  4521 New in Isabelle94-3
  4522 -------------------
  4523 
  4524 * new infix operator, addss, allowing the classical reasoner to
  4525 perform simplification at each step of its search.  Example:
  4526         fast_tac (cs addss ss)
  4527 
  4528 * a new logic, CHOL, the same as HOL, but with a curried syntax
  4529 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  4530 look like (a,b) instead of <a,b>;
  4531 
  4532 * PLEASE NOTE: CHOL will eventually replace HOL!
  4533 
  4534 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  4535 It translates to the operator "split".  A new theory of integers is available;
  4536 
  4537 * In ZF, integer numerals now denote two's-complement binary integers.
  4538 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  4539 
  4540 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  4541 of the Axiom of Choice;
  4542 
  4543 
  4544 
  4545 New in Isabelle94-2
  4546 -------------------
  4547 
  4548 * Significantly faster resolution;
  4549 
  4550 * the different sections in a .thy file can now be mixed and repeated
  4551 freely;
  4552 
  4553 * Database of theorems for FOL, HOL and ZF.  New
  4554 commands including qed, qed_goal and bind_thm store theorems in the database.
  4555 
  4556 * Simple database queries: return a named theorem (get_thm) or all theorems of
  4557 a given theory (thms_of), or find out what theory a theorem was proved in
  4558 (theory_of_thm);
  4559 
  4560 * Bugs fixed in the inductive definition and datatype packages;
  4561 
  4562 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  4563 and HOL_dup_cs obsolete;
  4564 
  4565 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  4566 have been removed;
  4567 
  4568 * Simpler definition of function space in ZF;
  4569 
  4570 * new results about cardinal and ordinal arithmetic in ZF;
  4571 
  4572 * 'subtype' facility in HOL for introducing new types as subsets of existing
  4573 types;
  4574 
  4575 
  4576 $Id$