NEWS
author wenzelm
Mon May 03 10:57:14 1999 +0200 (1999-05-03)
changeset 6563 128cf997c768
parent 6533 b8929d23aaa4
child 6671 677713791bd8
permissions -rw-r--r--
tuned;
     1 
     2 Isabelle NEWS -- history user-relevant changes
     3 ==============================================
     4 
     5 New in this Isabelle version
     6 ----------------------------
     7 
     8 *** Overview of INCOMPATIBILITIES (see below for more details) ***
     9 
    10 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
    11 complement;
    12 
    13 * HOL: the predicate "inj" is now defined by translation to "inj_on";
    14 
    15 * HOL/typedef: fixed type inference for representing set; type
    16 arguments now have to occur explicitly on the rhs as type constraints;
    17 
    18 * ZF: The con_defs part of an inductive definition may no longer refer
    19 to constants declared in the same theory;
    20 
    21 * HOL, ZF: the function mk_cases, generated by the inductive
    22 definition package, has lost an argument.  To simplify its result, it
    23 uses the default simpset instead of a supplied list of theorems.
    24 
    25 
    26 *** Proof tools ***
    27 
    28 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
    29 decision procedure for linear arithmetic. Currently it is used for
    30 types `nat' and `int' in HOL (see below) but can, should and will be
    31 instantiated for other types and logics as well.
    32 
    33 
    34 *** General ***
    35 
    36 * theory loader rewritten from scratch (may not be fully
    37 bug-compatible); old loadpath variable has been replaced by show_path,
    38 add_path, del_path, reset_path functions;
    39 
    40 * in locales, the "assumes" and "defines" parts may be omitted if
    41 empty;
    42 
    43 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
    44 long arrows);
    45 
    46 * new print_mode "HTML";
    47 
    48 * path element specification '~~' refers to '$ISABELLE_HOME';
    49 
    50 * new flag show_tags controls display of tags of theorems (which are
    51 basically just comments that may be attached by some tools);
    52 
    53 * improved isatool install: option -k creates KDE application icon,
    54 option -p DIR installs standalone binaries;
    55 
    56 * added ML_PLATFORM setting (useful for cross-platform installations);
    57 
    58 * Isamode 2.6 requires patch to accomodate change of Isabelle font
    59 mode and goal output format:
    60 
    61 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
    62 244c244
    63 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
    64 ---
    65 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
    66 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
    67 181c181
    68 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
    69 ---
    70 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
    71 
    72 
    73 *** HOL ***
    74 
    75 * There are now decision procedures for linear arithmetic over nat and
    76 int:
    77 
    78 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
    79 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
    80 are treated as atomic; subformulae not involving type `nat' or `int'
    81 are ignored; quantified subformulae are ignored unless they are
    82 positive universal or negative existential. The tactic has to be
    83 invoked by hand and can be a little bit slow. In particular, the
    84 running time is exponential in the number of occurrences of `min' and
    85 `max', and `-' on `nat'.
    86 
    87 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
    88 (negated) (in)equalities among the premises and the conclusion into
    89 account (i.e. no compound formulae) and does not know about `min' and
    90 `max', and `-' on `nat'. It is fast and is used automatically by the
    91 simplifier.
    92 
    93 NB: At the moment, these decision procedures do not cope with mixed
    94 nat/int formulae where the two parts interact, such as `m < n ==>
    95 int(m) < int(n)'.
    96 
    97 * New bounded quantifier syntax (input only):
    98   ! x < y. P, ! x <= y. P, ? x < y. P, ? x <= y. P
    99 
   100 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
   101 -- avoids syntactic ambiguities and treats state, transition, and
   102 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
   103 changed syntax and (many) tactics;
   104 
   105 * HOL/typedef: fixed type inference for representing set; type
   106 arguments now have to occur explicitly on the rhs as type constraints;
   107 
   108 * HOL/recdef (TFL) now requires theory Recdef;
   109 
   110 
   111 *** ZF ***
   112 
   113 * new primrec section allows primitive recursive functions to be given
   114 directly (as in HOL) over datatypes and the natural numbers;
   115 
   116 * new tactics induct_tac and exhaust_tac for induction (or case
   117 analysis) over datatypes and the natural numbers;
   118 
   119 * the datatype declaration of type T now defines the recursor T_rec;
   120 
   121 * simplification automatically does freeness reasoning for datatype
   122 constructors;
   123 
   124 * automatic type-inference, with AddTCs command to insert new
   125 type-checking rules;
   126 
   127 * datatype introduction rules are now added as Safe Introduction rules
   128 to the claset;
   129 
   130 * the syntax "if P then x else y" is now available in addition to
   131 if(P,x,y);
   132 
   133 
   134 *** Internal programming interfaces ***
   135 
   136 * AxClass.axclass_tac lost the theory argument;
   137 
   138 * tuned current_goals_markers semantics: begin / end goal avoids
   139 printing empty lines;
   140 
   141 * removed prs and prs_fn hook, which was broken because it did not
   142 include \n in its semantics, forcing writeln to add one
   143 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
   144 string -> unit if you really want to output text without newline;
   145 
   146 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
   147 plain output, interface builders may have to enable 'isabelle_font'
   148 mode to get Isabelle font glyphs as before;
   149 
   150 * refined token_translation interface; INCOMPATIBILITY: output length
   151 now of type real instead of int;
   152 
   153 
   154 
   155 New in Isabelle98-1 (October 1998)
   156 ----------------------------------
   157 
   158 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   159 
   160 * several changes of automated proof tools;
   161 
   162 * HOL: major changes to the inductive and datatype packages, including
   163 some minor incompatibilities of theory syntax;
   164 
   165 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
   166 called `inj_on';
   167 
   168 * HOL: removed duplicate thms in Arith:
   169   less_imp_add_less  should be replaced by  trans_less_add1
   170   le_imp_add_le      should be replaced by  trans_le_add1
   171 
   172 * HOL: unary minus is now overloaded (new type constraints may be
   173 required);
   174 
   175 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
   176 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
   177 now taken as an integer constant.
   178 
   179 * Pure: ML function 'theory_of' renamed to 'theory';
   180 
   181 
   182 *** Proof tools ***
   183 
   184 * Simplifier:
   185   1. Asm_full_simp_tac is now more aggressive.
   186      1. It will sometimes reorient premises if that increases their power to
   187         simplify.
   188      2. It does no longer proceed strictly from left to right but may also
   189         rotate premises to achieve further simplification.
   190      For compatibility reasons there is now Asm_lr_simp_tac which is like the
   191      old Asm_full_simp_tac in that it does not rotate premises.
   192   2. The simplifier now knows a little bit about nat-arithmetic.
   193 
   194 * Classical reasoner: wrapper mechanism for the classical reasoner now
   195 allows for selected deletion of wrappers, by introduction of names for
   196 wrapper functionals.  This implies that addbefore, addSbefore,
   197 addaltern, and addSaltern now take a pair (name, tactic) as argument,
   198 and that adding two tactics with the same name overwrites the first
   199 one (emitting a warning).
   200   type wrapper = (int -> tactic) -> (int -> tactic)
   201   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
   202   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
   203   delWrapper, delSWrapper: claset *  string            -> claset
   204   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
   205 
   206 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
   207 semantics; addbefore now affects only the unsafe part of step_tac
   208 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
   209 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
   210 by Force_tac;
   211 
   212 * Classical reasoner: setwrapper to setWrapper and compwrapper to
   213 compWrapper; added safe wrapper (and access functions for it);
   214 
   215 * HOL/split_all_tac is now much faster and fails if there is nothing
   216 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
   217 and the names of the automatically generated variables have changed.
   218 split_all_tac has moved within claset() from unsafe wrappers to safe
   219 wrappers, which means that !!-bound variables are split much more
   220 aggressively, and safe_tac and clarify_tac now split such variables.
   221 If this splitting is not appropriate, use delSWrapper "split_all_tac".
   222 Note: the same holds for record_split_tac, which does the job of
   223 split_all_tac for record fields.
   224 
   225 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
   226 permanently to the default simpset using Addsplits just like
   227 Addsimps. They can be removed via Delsplits just like
   228 Delsimps. Lower-case versions are also available.
   229 
   230 * HOL/Simplifier: The rule split_if is now part of the default
   231 simpset. This means that the simplifier will eliminate all occurrences
   232 of if-then-else in the conclusion of a goal. To prevent this, you can
   233 either remove split_if completely from the default simpset by
   234 `Delsplits [split_if]' or remove it in a specific call of the
   235 simplifier using `... delsplits [split_if]'.  You can also add/delete
   236 other case splitting rules to/from the default simpset: every datatype
   237 generates suitable rules `split_t_case' and `split_t_case_asm' (where
   238 t is the name of the datatype).
   239 
   240 * Classical reasoner / Simplifier combination: new force_tac (and
   241 derivatives Force_tac, force) combines rewriting and classical
   242 reasoning (and whatever other tools) similarly to auto_tac, but is
   243 aimed to solve the given subgoal completely.
   244 
   245 
   246 *** General ***
   247 
   248 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
   249 and `goalw': the theory is no longer needed as an explicit argument -
   250 the current theory context is used; assumptions are no longer returned
   251 at the ML-level unless one of them starts with ==> or !!; it is
   252 recommended to convert to these new commands using isatool fixgoal
   253 (backup your sources first!);
   254 
   255 * new top-level commands 'thm' and 'thms' for retrieving theorems from
   256 the current theory context, and 'theory' to lookup stored theories;
   257 
   258 * new theory section 'locale' for declaring constants, assumptions and
   259 definitions that have local scope;
   260 
   261 * new theory section 'nonterminals' for purely syntactic types;
   262 
   263 * new theory section 'setup' for generic ML setup functions
   264 (e.g. package initialization);
   265 
   266 * the distribution now includes Isabelle icons: see
   267 lib/logo/isabelle-{small,tiny}.xpm;
   268 
   269 * isatool install - install binaries with absolute references to
   270 ISABELLE_HOME/bin;
   271 
   272 * isatool logo -- create instances of the Isabelle logo (as EPS);
   273 
   274 * print mode 'emacs' reserved for Isamode;
   275 
   276 * support multiple print (ast) translations per constant name;
   277 
   278 
   279 *** HOL ***
   280 
   281 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
   282 
   283 * HOL/inductive package reorganized and improved: now supports mutual
   284 definitions such as
   285 
   286   inductive EVEN ODD
   287     intrs
   288       null "0 : EVEN"
   289       oddI "n : EVEN ==> Suc n : ODD"
   290       evenI "n : ODD ==> Suc n : EVEN"
   291 
   292 new theorem list "elims" contains an elimination rule for each of the
   293 recursive sets; inductive definitions now handle disjunctive premises
   294 correctly (also ZF);
   295 
   296 INCOMPATIBILITIES: requires Inductive as an ancestor; component
   297 "mutual_induct" no longer exists - the induction rule is always
   298 contained in "induct";
   299 
   300 
   301 * HOL/datatype package re-implemented and greatly improved: now
   302 supports mutually recursive datatypes such as
   303 
   304   datatype
   305     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
   306             | SUM ('a aexp) ('a aexp)
   307             | DIFF ('a aexp) ('a aexp)
   308             | NUM 'a
   309   and
   310     'a bexp = LESS ('a aexp) ('a aexp)
   311             | AND ('a bexp) ('a bexp)
   312             | OR ('a bexp) ('a bexp)
   313 
   314 as well as indirectly recursive datatypes such as
   315 
   316   datatype
   317     ('a, 'b) term = Var 'a
   318                   | App 'b ((('a, 'b) term) list)
   319 
   320 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
   321 induction on mutually / indirectly recursive datatypes.
   322 
   323 Primrec equations are now stored in theory and can be accessed via
   324 <function_name>.simps.
   325 
   326 INCOMPATIBILITIES:
   327 
   328   - Theories using datatypes must now have theory Datatype as an
   329     ancestor.
   330   - The specific <typename>.induct_tac no longer exists - use the
   331     generic induct_tac instead.
   332   - natE has been renamed to nat.exhaust - use exhaust_tac
   333     instead of res_inst_tac ... natE. Note that the variable
   334     names in nat.exhaust differ from the names in natE, this
   335     may cause some "fragile" proofs to fail.
   336   - The theorems split_<typename>_case and split_<typename>_case_asm
   337     have been renamed to <typename>.split and <typename>.split_asm.
   338   - Since default sorts of type variables are now handled correctly,
   339     some datatype definitions may have to be annotated with explicit
   340     sort constraints.
   341   - Primrec definitions no longer require function name and type
   342     of recursive argument.
   343 
   344 Consider using isatool fixdatatype to adapt your theories and proof
   345 scripts to the new package (backup your sources first!).
   346 
   347 
   348 * HOL/record package: considerably improved implementation; now
   349 includes concrete syntax for record types, terms, updates; theorems
   350 for surjective pairing and splitting !!-bound record variables; proof
   351 support is as follows:
   352 
   353   1) standard conversions (selectors or updates applied to record
   354 constructor terms) are part of the standard simpset;
   355 
   356   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
   357 made part of standard simpset and claset via addIffs;
   358 
   359   3) a tactic for record field splitting (record_split_tac) is part of
   360 the standard claset (addSWrapper);
   361 
   362 To get a better idea about these rules you may retrieve them via
   363 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
   364 the name of your record type.
   365 
   366 The split tactic 3) conceptually simplifies by the following rule:
   367 
   368   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
   369 
   370 Thus any record variable that is bound by meta-all will automatically
   371 blow up into some record constructor term, consequently the
   372 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
   373 solve record problems automatically.
   374 
   375 
   376 * reorganized the main HOL image: HOL/Integ and String loaded by
   377 default; theory Main includes everything;
   378 
   379 * automatic simplification of integer sums and comparisons, using cancellation;
   380 
   381 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
   382 
   383 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
   384 
   385 * many new identities for unions, intersections, set difference, etc.;
   386 
   387 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
   388 called split_if, split_split, split_sum_case and split_nat_case (to go
   389 with add/delsplits);
   390 
   391 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
   392 (?x::unit) = (); this is made part of the default simpset, which COULD
   393 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
   394 'Delsimprocs [unit_eq_proc];' as last resort); also note that
   395 unit_abs_eta_conv is added in order to counter the effect of
   396 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
   397 %u.f();
   398 
   399 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
   400 makes more sense);
   401 
   402 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   403   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   404   disjointness reasoning but breaking a few old proofs.
   405 
   406 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
   407 to 'converse' from 'inverse' (for compatibility with ZF and some
   408 literature);
   409 
   410 * HOL/recdef can now declare non-recursive functions, with {} supplied as
   411 the well-founded relation;
   412 
   413 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
   414     Compl A.  The "Compl" syntax remains available as input syntax for this
   415     release ONLY.
   416 
   417 * HOL/Update: new theory of function updates:
   418     f(a:=b) == %x. if x=a then b else f x
   419 may also be iterated as in f(a:=b,c:=d,...);
   420 
   421 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
   422 
   423 * HOL/List:
   424   - new function list_update written xs[i:=v] that updates the i-th
   425     list position. May also be iterated as in xs[i:=a,j:=b,...].
   426   - new function `upt' written [i..j(] which generates the list
   427     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
   428     bound write [i..j], which is a shorthand for [i..j+1(].
   429   - new lexicographic orderings and corresponding wellfoundedness theorems.
   430 
   431 * HOL/Arith:
   432   - removed 'pred' (predecessor) function;
   433   - generalized some theorems about n-1;
   434   - many new laws about "div" and "mod";
   435   - new laws about greatest common divisors (see theory ex/Primes);
   436 
   437 * HOL/Relation: renamed the relational operator r^-1 "converse"
   438 instead of "inverse";
   439 
   440 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
   441   of the multiset ordering;
   442 
   443 * directory HOL/Real: a construction of the reals using Dedekind cuts
   444   (not included by default);
   445 
   446 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
   447 
   448 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
   449   programs, i.e. different program variables may have different types.
   450 
   451 * calling (stac rew i) now fails if "rew" has no effect on the goal
   452   [previously, this check worked only if the rewrite rule was unconditional]
   453   Now rew can involve either definitions or equalities (either == or =).
   454 
   455 
   456 *** ZF ***
   457 
   458 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
   459   only the theorems proved on ZF.ML;
   460 
   461 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   462   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   463   disjointness reasoning but breaking a few old proofs.
   464 
   465 * ZF/Update: new theory of function updates
   466     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
   467   may also be iterated as in f(a:=b,c:=d,...);
   468 
   469 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
   470 
   471 * calling (stac rew i) now fails if "rew" has no effect on the goal
   472   [previously, this check worked only if the rewrite rule was unconditional]
   473   Now rew can involve either definitions or equalities (either == or =).
   474 
   475 * case_tac provided for compatibility with HOL
   476     (like the old excluded_middle_tac, but with subgoals swapped)
   477 
   478 
   479 *** Internal programming interfaces ***
   480 
   481 * Pure: several new basic modules made available for general use, see
   482 also src/Pure/README;
   483 
   484 * improved the theory data mechanism to support encapsulation (data
   485 kind name replaced by private Object.kind, acting as authorization
   486 key); new type-safe user interface via functor TheoryDataFun; generic
   487 print_data function becomes basically useless;
   488 
   489 * removed global_names compatibility flag -- all theory declarations
   490 are qualified by default;
   491 
   492 * module Pure/Syntax now offers quote / antiquote translation
   493 functions (useful for Hoare logic etc. with implicit dependencies);
   494 see HOL/ex/Antiquote for an example use;
   495 
   496 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
   497 cterm -> thm;
   498 
   499 * new tactical CHANGED_GOAL for checking that a tactic modifies a
   500 subgoal;
   501 
   502 * Display.print_goals function moved to Locale.print_goals;
   503 
   504 * standard print function for goals supports current_goals_markers
   505 variable for marking begin of proof, end of proof, start of goal; the
   506 default is ("", "", ""); setting current_goals_markers := ("<proof>",
   507 "</proof>", "<goal>") causes SGML like tagged proof state printing,
   508 for example;
   509 
   510 
   511 
   512 New in Isabelle98 (January 1998)
   513 --------------------------------
   514 
   515 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   516 
   517 * changed lexical syntax of terms / types: dots made part of long
   518 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
   519 
   520 * simpset (and claset) reference variable replaced by functions
   521 simpset / simpset_ref;
   522 
   523 * no longer supports theory aliases (via merge) and non-trivial
   524 implicit merge of thms' signatures;
   525 
   526 * most internal names of constants changed due to qualified names;
   527 
   528 * changed Pure/Sequence interface (see Pure/seq.ML);
   529 
   530 
   531 *** General Changes ***
   532 
   533 * hierachically structured name spaces (for consts, types, axms, thms
   534 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
   535 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
   536 isatool fixdots ensures space after dots (e.g. "%x. x"); set
   537 long_names for fully qualified output names; NOTE: ML programs
   538 (special tactics, packages etc.) referring to internal names may have
   539 to be adapted to cope with fully qualified names; in case of severe
   540 backward campatibility problems try setting 'global_names' at compile
   541 time to have enrything declared within a flat name space; one may also
   542 fine tune name declarations in theories via the 'global' and 'local'
   543 section;
   544 
   545 * reimplemented the implicit simpset and claset using the new anytype
   546 data filed in signatures; references simpset:simpset ref etc. are
   547 replaced by functions simpset:unit->simpset and
   548 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
   549 to patch your ML files accordingly;
   550 
   551 * HTML output now includes theory graph data for display with Java
   552 applet or isatool browser; data generated automatically via isatool
   553 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
   554 
   555 * defs may now be conditional; improved rewrite_goals_tac to handle
   556 conditional equations;
   557 
   558 * defs now admits additional type arguments, using TYPE('a) syntax;
   559 
   560 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
   561 creates a new theory node; implicit merge of thms' signatures is
   562 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
   563 transfer:theory->thm->thm in (rare) cases;
   564 
   565 * improved handling of draft signatures / theories; draft thms (and
   566 ctyps, cterms) are automatically promoted to real ones;
   567 
   568 * slightly changed interfaces for oracles: admit many per theory, named
   569 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
   570 
   571 * print_goals: optional output of const types (set show_consts and
   572 show_types);
   573 
   574 * improved output of warnings (###) and errors (***);
   575 
   576 * subgoal_tac displays a warning if the new subgoal has type variables;
   577 
   578 * removed old README and Makefiles;
   579 
   580 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
   581 
   582 * removed obsolete init_pps and init_database;
   583 
   584 * deleted the obsolete tactical STATE, which was declared by
   585     fun STATE tacfun st = tacfun st st;
   586 
   587 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
   588 (which abbreviates $HOME);
   589 
   590 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
   591 use isatool fixseq to adapt your ML programs (this works for fully
   592 qualified references to the Sequence structure only!);
   593 
   594 * use_thy no longer requires writable current directory; it always
   595 reloads .ML *and* .thy file, if either one is out of date;
   596 
   597 
   598 *** Classical Reasoner ***
   599 
   600 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
   601 tactics that use classical reasoning to simplify a subgoal without
   602 splitting it into several subgoals;
   603 
   604 * Safe_tac: like safe_tac but uses the default claset;
   605 
   606 
   607 *** Simplifier ***
   608 
   609 * added simplification meta rules:
   610     (asm_)(full_)simplify: simpset -> thm -> thm;
   611 
   612 * simplifier.ML no longer part of Pure -- has to be loaded by object
   613 logics (again);
   614 
   615 * added prems argument to simplification procedures;
   616 
   617 * HOL, FOL, ZF: added infix function `addsplits':
   618   instead of `<simpset> setloop (split_tac <thms>)'
   619   you can simply write `<simpset> addsplits <thms>'
   620 
   621 
   622 *** Syntax ***
   623 
   624 * TYPE('a) syntax for type reflection terms;
   625 
   626 * no longer handles consts with name "" -- declare as 'syntax' instead;
   627 
   628 * pretty printer: changed order of mixfix annotation preference (again!);
   629 
   630 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
   631 
   632 
   633 *** HOL ***
   634 
   635 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
   636   with `addloop' of the simplifier to faciliate case splitting in premises.
   637 
   638 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
   639 
   640 * HOL/Auth: new protocol proofs including some for the Internet
   641   protocol TLS;
   642 
   643 * HOL/Map: new theory of `maps' a la VDM;
   644 
   645 * HOL/simplifier: simplification procedures nat_cancel_sums for
   646 cancelling out common nat summands from =, <, <= (in)equalities, or
   647 differences; simplification procedures nat_cancel_factor for
   648 cancelling common factor from =, <, <= (in)equalities over natural
   649 sums; nat_cancel contains both kinds of procedures, it is installed by
   650 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
   651 
   652 * HOL/simplifier: terms of the form
   653   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
   654   are rewritten to
   655   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
   656   and those of the form
   657   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
   658   are rewritten to
   659   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
   660 
   661 * HOL/datatype
   662   Each datatype `t' now comes with a theorem `split_t_case' of the form
   663 
   664   P(t_case f1 ... fn x) =
   665      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
   666         ...
   667        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
   668      )
   669 
   670   and a theorem `split_t_case_asm' of the form
   671 
   672   P(t_case f1 ... fn x) =
   673     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
   674         ...
   675        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
   676      )
   677   which can be added to a simpset via `addsplits'. The existing theorems
   678   expand_list_case and expand_option_case have been renamed to
   679   split_list_case and split_option_case.
   680 
   681 * HOL/Arithmetic:
   682   - `pred n' is automatically converted to `n-1'.
   683     Users are strongly encouraged not to use `pred' any longer,
   684     because it will disappear altogether at some point.
   685   - Users are strongly encouraged to write "0 < n" rather than
   686     "n ~= 0". Theorems and proof tools have been modified towards this
   687     `standard'.
   688 
   689 * HOL/Lists:
   690   the function "set_of_list" has been renamed "set" (and its theorems too);
   691   the function "nth" now takes its arguments in the reverse order and
   692   has acquired the infix notation "!" as in "xs!n".
   693 
   694 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
   695 
   696 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
   697   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
   698 
   699 * HOL/record: extensible records with schematic structural subtyping
   700 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
   701 still lacks various theorems and concrete record syntax;
   702 
   703 
   704 *** HOLCF ***
   705 
   706 * removed "axioms" and "generated by" sections;
   707 
   708 * replaced "ops" section by extended "consts" section, which is capable of
   709   handling the continuous function space "->" directly;
   710 
   711 * domain package:
   712   . proves theorems immediately and stores them in the theory,
   713   . creates hierachical name space,
   714   . now uses normal mixfix annotations (instead of cinfix...),
   715   . minor changes to some names and values (for consistency),
   716   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
   717   . separator between mutual domain defs: changed "," to "and",
   718   . improved handling of sort constraints;  now they have to
   719     appear on the left-hand side of the equations only;
   720 
   721 * fixed LAM <x,y,zs>.b syntax;
   722 
   723 * added extended adm_tac to simplifier in HOLCF -- can now discharge
   724 adm (%x. P (t x)), where P is chainfinite and t continuous;
   725 
   726 
   727 *** FOL and ZF ***
   728 
   729 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
   730   with `addloop' of the simplifier to faciliate case splitting in premises.
   731 
   732 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
   733 in HOL, they strip ALL and --> from proved theorems;
   734 
   735 
   736 
   737 New in Isabelle94-8 (May 1997)
   738 ------------------------------
   739 
   740 *** General Changes ***
   741 
   742 * new utilities to build / run / maintain Isabelle etc. (in parts
   743 still somewhat experimental); old Makefiles etc. still functional;
   744 
   745 * new 'Isabelle System Manual';
   746 
   747 * INSTALL text, together with ./configure and ./build scripts;
   748 
   749 * reimplemented type inference for greater efficiency, better error
   750 messages and clean internal interface;
   751 
   752 * prlim command for dealing with lots of subgoals (an easier way of
   753 setting goals_limit);
   754 
   755 
   756 *** Syntax ***
   757 
   758 * supports alternative (named) syntax tables (parser and pretty
   759 printer); internal interface is provided by add_modesyntax(_i);
   760 
   761 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
   762 be used in conjunction with the Isabelle symbol font; uses the
   763 "symbols" syntax table;
   764 
   765 * added token_translation interface (may translate name tokens in
   766 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
   767 the current print_mode); IMPORTANT: user print translation functions
   768 are responsible for marking newly introduced bounds
   769 (Syntax.mark_boundT);
   770 
   771 * token translations for modes "xterm" and "xterm_color" that display
   772 names in bold, underline etc. or colors (which requires a color
   773 version of xterm);
   774 
   775 * infixes may now be declared with names independent of their syntax;
   776 
   777 * added typed_print_translation (like print_translation, but may
   778 access type of constant);
   779 
   780 
   781 *** Classical Reasoner ***
   782 
   783 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
   784 some limitations.  Blast_tac...
   785   + ignores addss, addbefore, addafter; this restriction is intrinsic
   786   + ignores elimination rules that don't have the correct format
   787         (the conclusion MUST be a formula variable)
   788   + ignores types, which can make HOL proofs fail
   789   + rules must not require higher-order unification, e.g. apply_type in ZF
   790     [message "Function Var's argument not a bound variable" relates to this]
   791   + its proof strategy is more general but can actually be slower
   792 
   793 * substitution with equality assumptions no longer permutes other
   794 assumptions;
   795 
   796 * minor changes in semantics of addafter (now called addaltern); renamed
   797 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
   798 (and access functions for it);
   799 
   800 * improved combination of classical reasoner and simplifier:
   801   + functions for handling clasimpsets
   802   + improvement of addss: now the simplifier is called _after_ the
   803     safe steps.
   804   + safe variant of addss called addSss: uses safe simplifications
   805     _during_ the safe steps. It is more complete as it allows multiple
   806     instantiations of unknowns (e.g. with slow_tac).
   807 
   808 *** Simplifier ***
   809 
   810 * added interface for simplification procedures (functions that
   811 produce *proven* rewrite rules on the fly, depending on current
   812 redex);
   813 
   814 * ordering on terms as parameter (used for ordered rewriting);
   815 
   816 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
   817 
   818 * the solver is now split into a safe and an unsafe part.
   819 This should be invisible for the normal user, except that the
   820 functions setsolver and addsolver have been renamed to setSolver and
   821 addSolver; added safe_asm_full_simp_tac;
   822 
   823 
   824 *** HOL ***
   825 
   826 * a generic induction tactic `induct_tac' which works for all datatypes and
   827 also for type `nat';
   828 
   829 * a generic case distinction tactic `exhaust_tac' which works for all
   830 datatypes and also for type `nat';
   831 
   832 * each datatype comes with a function `size';
   833 
   834 * patterns in case expressions allow tuple patterns as arguments to
   835 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
   836 
   837 * primrec now also works with type nat;
   838 
   839 * recdef: a new declaration form, allows general recursive functions to be
   840 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
   841 
   842 * the constant for negation has been renamed from "not" to "Not" to
   843 harmonize with FOL, ZF, LK, etc.;
   844 
   845 * HOL/ex/LFilter theory of a corecursive "filter" functional for
   846 infinite lists;
   847 
   848 * HOL/Modelcheck demonstrates invocation of model checker oracle;
   849 
   850 * HOL/ex/Ring.thy declares cring_simp, which solves equational
   851 problems in commutative rings, using axiomatic type classes for + and *;
   852 
   853 * more examples in HOL/MiniML and HOL/Auth;
   854 
   855 * more default rewrite rules for quantifiers, union/intersection;
   856 
   857 * a new constant `arbitrary == @x.False';
   858 
   859 * HOLCF/IOA replaces old HOL/IOA;
   860 
   861 * HOLCF changes: derived all rules and arities
   862   + axiomatic type classes instead of classes
   863   + typedef instead of faking type definitions
   864   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
   865   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
   866   + eliminated the types void, one, tr
   867   + use unit lift and bool lift (with translations) instead of one and tr
   868   + eliminated blift from Lift3.thy (use Def instead of blift)
   869   all eliminated rules are derived as theorems --> no visible changes ;
   870 
   871 
   872 *** ZF ***
   873 
   874 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
   875 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
   876 as ZF_cs addSIs [equalityI];
   877 
   878 
   879 
   880 New in Isabelle94-7 (November 96)
   881 ---------------------------------
   882 
   883 * allowing negative levels (as offsets) in prlev and choplev;
   884 
   885 * super-linear speedup for large simplifications;
   886 
   887 * FOL, ZF and HOL now use miniscoping: rewriting pushes
   888 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
   889 FAIL); can suppress it using the command Delsimps (ex_simps @
   890 all_simps); De Morgan laws are also now included, by default;
   891 
   892 * improved printing of ==>  :  ~:
   893 
   894 * new object-logic "Sequents" adds linear logic, while replacing LK
   895 and Modal (thanks to Sara Kalvala);
   896 
   897 * HOL/Auth: correctness proofs for authentication protocols;
   898 
   899 * HOL: new auto_tac combines rewriting and classical reasoning (many
   900 examples on HOL/Auth);
   901 
   902 * HOL: new command AddIffs for declaring theorems of the form P=Q to
   903 the rewriter and classical reasoner simultaneously;
   904 
   905 * function uresult no longer returns theorems in "standard" format;
   906 regain previous version by: val uresult = standard o uresult;
   907 
   908 
   909 
   910 New in Isabelle94-6
   911 -------------------
   912 
   913 * oracles -- these establish an interface between Isabelle and trusted
   914 external reasoners, which may deliver results as theorems;
   915 
   916 * proof objects (in particular record all uses of oracles);
   917 
   918 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
   919 
   920 * "constdefs" section in theory files;
   921 
   922 * "primrec" section (HOL) no longer requires names;
   923 
   924 * internal type "tactic" now simply "thm -> thm Sequence.seq";
   925 
   926 
   927 
   928 New in Isabelle94-5
   929 -------------------
   930 
   931 * reduced space requirements;
   932 
   933 * automatic HTML generation from theories;
   934 
   935 * theory files no longer require "..." (quotes) around most types;
   936 
   937 * new examples, including two proofs of the Church-Rosser theorem;
   938 
   939 * non-curried (1994) version of HOL is no longer distributed;
   940 
   941 
   942 
   943 New in Isabelle94-4
   944 -------------------
   945 
   946 * greatly reduced space requirements;
   947 
   948 * theory files (.thy) no longer require \...\ escapes at line breaks;
   949 
   950 * searchable theorem database (see the section "Retrieving theorems" on
   951 page 8 of the Reference Manual);
   952 
   953 * new examples, including Grabczewski's monumental case study of the
   954 Axiom of Choice;
   955 
   956 * The previous version of HOL renamed to Old_HOL;
   957 
   958 * The new version of HOL (previously called CHOL) uses a curried syntax
   959 for functions.  Application looks like f a b instead of f(a,b);
   960 
   961 * Mutually recursive inductive definitions finally work in HOL;
   962 
   963 * In ZF, pattern-matching on tuples is now available in all abstractions and
   964 translates to the operator "split";
   965 
   966 
   967 
   968 New in Isabelle94-3
   969 -------------------
   970 
   971 * new infix operator, addss, allowing the classical reasoner to
   972 perform simplification at each step of its search.  Example:
   973         fast_tac (cs addss ss)
   974 
   975 * a new logic, CHOL, the same as HOL, but with a curried syntax
   976 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
   977 look like (a,b) instead of <a,b>;
   978 
   979 * PLEASE NOTE: CHOL will eventually replace HOL!
   980 
   981 * In CHOL, pattern-matching on tuples is now available in all abstractions.
   982 It translates to the operator "split".  A new theory of integers is available;
   983 
   984 * In ZF, integer numerals now denote two's-complement binary integers.
   985 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
   986 
   987 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
   988 of the Axiom of Choice;
   989 
   990 
   991 
   992 New in Isabelle94-2
   993 -------------------
   994 
   995 * Significantly faster resolution;
   996 
   997 * the different sections in a .thy file can now be mixed and repeated
   998 freely;
   999 
  1000 * Database of theorems for FOL, HOL and ZF.  New
  1001 commands including qed, qed_goal and bind_thm store theorems in the database.
  1002 
  1003 * Simple database queries: return a named theorem (get_thm) or all theorems of
  1004 a given theory (thms_of), or find out what theory a theorem was proved in
  1005 (theory_of_thm);
  1006 
  1007 * Bugs fixed in the inductive definition and datatype packages;
  1008 
  1009 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  1010 and HOL_dup_cs obsolete;
  1011 
  1012 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  1013 have been removed;
  1014 
  1015 * Simpler definition of function space in ZF;
  1016 
  1017 * new results about cardinal and ordinal arithmetic in ZF;
  1018 
  1019 * 'subtype' facility in HOL for introducing new types as subsets of existing
  1020 types;
  1021 
  1022 
  1023 $Id$