NEWS
author nipkow
Fri Oct 09 14:19:13 1998 +0200 (1998-10-09)
changeset 5633 fb7fa1b154c4
parent 5572 53c6ea1e6d94
child 5650 38bda28c68a2
permissions -rw-r--r--
Added a few breaks in error text.
     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 * several changes of proof tools;
    11 
    12 * HOL: new version of inductive and datatype;
    13 
    14 * HOL: major changes to the inductive and datatype packages;
    15 
    16 * HOL: renamed r^-1 to 'converse' from 'inverse'; `inj_onto' is now
    17 called `inj_on';
    18 
    19 * HOL: removed duplicate thms in Arith:
    20   less_imp_add_less  should be replaced by  trans_less_add1
    21   le_imp_add_le      should be replaced by  trans_le_add1
    22 
    23 * HOL: unary - is now overloaded (new type constraints may be required);
    24 
    25 * HOL and ZF: unary minus for integers is now #- instead of #~.  In ZF, 
    26   expressions such as n#-1 must be changed to n#- 1, since #-1 is now taken
    27   as an integer constant.
    28 
    29 * Pure: ML function 'theory_of' replaced by 'theory';
    30 
    31 
    32 *** Proof tools ***
    33 
    34 * Simplifier: Asm_full_simp_tac is now more aggressive.
    35   1. It will sometimes reorient premises if that increases their power to
    36      simplify.
    37   2. It does no longer proceed strictly from left to right but may also
    38      rotate premises to achieve further simplification.
    39   For compatibility reasons there is now Asm_lr_simp_tac which is like the
    40   old Asm_full_simp_tac in that it does not rotate premises.
    41 
    42 * Classical reasoner: wrapper mechanism for the classical reasoner now
    43 allows for selected deletion of wrappers, by introduction of names for
    44 wrapper functionals.  This implies that addbefore, addSbefore,
    45 addaltern, and addSaltern now take a pair (name, tactic) as argument,
    46 and that adding two tactics with the same name overwrites the first
    47 one (emitting a warning).
    48   type wrapper = (int -> tactic) -> (int -> tactic)
    49   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
    50   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
    51   delWrapper, delSWrapper: claset *  string            -> claset
    52   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
    53 
    54 * Classical reasoner: addbefore / addSbefore now have APPEND / ORELSE semantics;
    55   addbefore now affects only the unsafe part of step_tac etc.;
    56   This affects addss/auto_tac/force_tac, so EXISTING (INSTABLE) PROOFS MAY FAIL, but
    57   most proofs should be fixable easily, e.g. by replacing Auto_tac by Force_tac.
    58 
    59 * Classical reasoner: setwrapper to setWrapper and compwrapper to compWrapper; 
    60   added safe wrapper (and access functions for it);
    61 
    62 * HOL/split_all_tac is now much faster and fails if there is nothing
    63 to split.  Existing (fragile) proofs may require adaption because the
    64 order and the names of the automatically generated variables have
    65 changed.  split_all_tac has moved within claset() from unsafe wrappers
    66 to safe wrappers, which means that !!-bound variables are split much
    67 more aggressively, and safe_tac and clarify_tac now split such
    68 variables.  If this splitting is not appropriate, use delSWrapper
    69 "split_all_tac".
    70 
    71 * HOL/Simplifier:
    72 
    73  - Rewrite rules for case distinctions can now be added permanently to
    74    the default simpset using Addsplits just like Addsimps. They can be
    75    removed via Delsplits just like Delsimps. Lower-case versions are
    76    also available.
    77 
    78  - The rule split_if is now part of the default simpset. This means
    79    that the simplifier will eliminate all occurrences of if-then-else
    80    in the conclusion of a goal. To prevent this, you can either remove
    81    split_if completely from the default simpset by `Delsplits
    82    [split_if]' or remove it in a specific call of the simplifier using
    83    `... delsplits [split_if]'.  You can also add/delete other case
    84    splitting rules to/from the default simpset: every datatype
    85    generates suitable rules `split_t_case' and `split_t_case_asm'
    86    (where t is the name of the datatype).
    87 
    88 * Classical reasoner - Simplifier combination: new force_tac (and
    89 derivatives Force_tac, force) combines rewriting and classical
    90 reasoning (and whatever other tools) similarly to auto_tac, but is
    91 aimed to solve the given subgoal completely;
    92 
    93 
    94 *** General ***
    95 
    96 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
    97 and `goalw': the theory is no longer needed as an explicit argument -
    98 the current theory context is used; assumptions are no longer returned
    99 at the ML-level unless one of them starts with ==> or !!; it is
   100 recommended to convert to these new commands using isatool fixgoal
   101 (backup your sources first!);
   102 
   103 * new top-level commands 'thm' and 'thms' for retrieving theorems from
   104 the current theory context, and 'theory' to lookup stored theories;
   105 
   106 * new theory section 'nonterminals' for purely syntactic types;
   107 
   108 * new theory section 'setup' for generic ML setup functions
   109 (e.g. package initialization);
   110 
   111 * the distribution now includes Isabelle icons: see
   112 lib/logo/isabelle-{small,tiny}.xpm;
   113 
   114 * isatool install - install binaries with absolute references to
   115 ISABELLE_HOME/bin;
   116 
   117 * isatool logo -- create instances of the Isabelle logo (as EPS);
   118 
   119 * print mode 'emacs' reserved for Isamode;
   120 
   121 
   122 *** HOL ***
   123 
   124 * HOL/inductive package reorganized and improved: now supports mutual
   125 definitions such as
   126 
   127   inductive EVEN ODD
   128     intrs
   129       null "0 : EVEN"
   130       oddI "n : EVEN ==> Suc n : ODD"
   131       evenI "n : ODD ==> Suc n : EVEN"
   132 
   133 new theorem list "elims" contains an elimination rule for each of the
   134 recursive sets; inductive definitions now handle disjunctive premises
   135 correctly (also ZF);
   136 
   137 INCOMPATIBILITIES: requires Inductive as an ancestor; component
   138 "mutual_induct" no longer exists - the induction rule is always
   139 contained in "induct";
   140 
   141 
   142 * HOL/datatype package re-implemented and greatly improved: now
   143 supports mutually recursive datatypes such as
   144 
   145   datatype
   146     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
   147             | SUM ('a aexp) ('a aexp)
   148             | DIFF ('a aexp) ('a aexp)
   149             | NUM 'a
   150   and
   151     'a bexp = LESS ('a aexp) ('a aexp)
   152             | AND ('a bexp) ('a bexp)
   153             | OR ('a bexp) ('a bexp)
   154 
   155 as well as indirectly recursive datatypes such as
   156 
   157   datatype
   158     ('a, 'b) term = Var 'a
   159                   | App 'b ((('a, 'b) term) list)
   160 
   161 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
   162 induction on mutually / indirectly recursive datatypes.
   163 
   164 Primrec equations are now stored in theory and can be accessed via
   165 <function_name>.simps.
   166 
   167 INCOMPATIBILITIES:
   168 
   169   - Theories using datatypes must now have theory Datatype as an
   170     ancestor.
   171   - The specific <typename>.induct_tac no longer exists - use the
   172     generic induct_tac instead.
   173   - natE has been renamed to nat.exhaust - use exhaust_tac
   174     instead of res_inst_tac ... natE. Note that the variable
   175     names in nat.exhaust differ from the names in natE, this
   176     may cause some "fragile" proofs to fail.
   177   - The theorems split_<typename>_case and split_<typename>_case_asm
   178     have been renamed to <typename>.split and <typename>.split_asm.
   179   - Since default sorts of type variables are now handled correctly,
   180     some datatype definitions may have to be annotated with explicit
   181     sort constraints.
   182   - Primrec definitions no longer require function name and type
   183     of recursive argument.
   184 
   185 Consider using isatool fixdatatype to adapt your theories and proof
   186 scripts to the new package (backup your sources first!).
   187 
   188 
   189 * HOL/record package: now includes concrete syntax for record types,
   190 terms, updates; still lacks important theorems, like surjective
   191 pairing and split;
   192 
   193 * reorganized the main HOL image: HOL/Integ and String loaded by
   194 default; theory Main includes everything;
   195 
   196 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
   197 
   198 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
   199 
   200 * many new identities for unions, intersections, set difference, etc.;
   201 
   202 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
   203 called split_if, split_split, split_sum_case and split_nat_case (to go
   204 with add/delsplits);
   205 
   206 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
   207 (?x::unit) = (); this is made part of the default simpset, which COULD
   208 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
   209 'Delsimprocs [unit_eq_proc];' as last resort); also note that
   210 unit_abs_eta_conv is added in order to counter the effect of
   211 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
   212 %u.f();
   213 
   214 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
   215 makes more sense);
   216 
   217 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   218   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   219   disjointness reasoning but breaking a few old proofs.
   220 
   221 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
   222 to 'converse' from 'inverse' (for compatibility with ZF and some
   223 literature);
   224 
   225 * HOL/recdef can now declare non-recursive functions, with {} supplied as
   226 the well-founded relation;
   227 
   228 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
   229     Compl A.  The "Compl" syntax remains available as input syntax for this
   230     release ONLY.
   231 
   232 * HOL/Update: new theory of function updates:
   233     f(a:=b) == %x. if x=a then b else f x
   234 may also be iterated as in f(a:=b,c:=d,...);
   235 
   236 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
   237 
   238 * HOL/List:
   239   - new function list_update written xs[i:=v] that updates the i-th
   240     list position. May also be iterated as in xs[i:=a,j:=b,...].
   241   - new function `upt' written [i..j(] which generates the list
   242     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
   243     bound write [i..j], which is a shorthand for [i..j+1(].
   244   - new lexicographic orderings and corresponding wellfoundedness theorems.
   245 
   246 * HOL/Arith:
   247   - removed 'pred' (predecessor) function;
   248   - generalized some theorems about n-1;
   249   - many new laws about "div" and "mod";
   250   - new laws about greatest common divisors (see theory ex/Primes);
   251 
   252 * HOL/Relation: renamed the relational operator r^-1 "converse"
   253 instead of "inverse";
   254 
   255 * directory HOL/Real: a construction of the reals using Dedekind cuts
   256 (not included by default);
   257 
   258 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
   259 
   260 * calling (stac rew i) now fails if "rew" has no effect on the goal
   261   [previously, this check worked only if the rewrite rule was unconditional]
   262   Now rew can involve either definitions or equalities (either == or =).
   263 
   264 
   265 *** ZF ***
   266 
   267 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
   268   only the theorems proved on ZF.ML;
   269 
   270 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   271   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   272   disjointness reasoning but breaking a few old proofs.
   273 
   274 * ZF/Update: new theory of function updates
   275     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
   276   may also be iterated as in f(a:=b,c:=d,...);
   277 
   278 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
   279 
   280 * calling (stac rew i) now fails if "rew" has no effect on the goal
   281   [previously, this check worked only if the rewrite rule was unconditional]
   282   Now rew can involve either definitions or equalities (either == or =).
   283 
   284 * case_tac provided for compatibility with HOL
   285     (like the old excluded_middle_tac, but with subgoals swapped)
   286 
   287 
   288 *** Internal programming interfaces ***
   289 
   290 * Pure: several new basic modules made available for general use, see
   291 also src/Pure/README;
   292 
   293 * improved the theory data mechanism to support encapsulation (data
   294 kind name replaced by private Object.kind, acting as authorization
   295 key); new type-safe user interface via functor TheoryDataFun; generic
   296 print_data function becomes basically useless;
   297 
   298 * removed global_names compatibility flag -- all theory declarations
   299 are qualified by default;
   300 
   301 * module Pure/Syntax now offers quote / antiquote translation
   302 functions (useful for Hoare logic etc. with implicit dependencies);
   303 see HOL/ex/Antiquote for an example use;
   304 
   305 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
   306 cterm -> thm;
   307 
   308 * new tactical CHANGED_GOAL for checking that a tactic modifies a
   309 subgoal;
   310 
   311 * Display.print_goals function moved to Locale.print_goals;
   312 
   313 
   314 
   315 New in Isabelle98 (January 1998)
   316 --------------------------------
   317 
   318 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   319 
   320 * changed lexical syntax of terms / types: dots made part of long
   321 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
   322 
   323 * simpset (and claset) reference variable replaced by functions
   324 simpset / simpset_ref;
   325 
   326 * no longer supports theory aliases (via merge) and non-trivial
   327 implicit merge of thms' signatures;
   328 
   329 * most internal names of constants changed due to qualified names;
   330 
   331 * changed Pure/Sequence interface (see Pure/seq.ML);
   332 
   333 
   334 *** General Changes ***
   335 
   336 * hierachically structured name spaces (for consts, types, axms, thms
   337 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
   338 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
   339 isatool fixdots ensures space after dots (e.g. "%x. x"); set
   340 long_names for fully qualified output names; NOTE: ML programs
   341 (special tactics, packages etc.) referring to internal names may have
   342 to be adapted to cope with fully qualified names; in case of severe
   343 backward campatibility problems try setting 'global_names' at compile
   344 time to have enrything declared within a flat name space; one may also
   345 fine tune name declarations in theories via the 'global' and 'local'
   346 section;
   347 
   348 * reimplemented the implicit simpset and claset using the new anytype
   349 data filed in signatures; references simpset:simpset ref etc. are
   350 replaced by functions simpset:unit->simpset and
   351 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
   352 to patch your ML files accordingly;
   353 
   354 * HTML output now includes theory graph data for display with Java
   355 applet or isatool browser; data generated automatically via isatool
   356 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
   357 
   358 * defs may now be conditional; improved rewrite_goals_tac to handle
   359 conditional equations;
   360 
   361 * defs now admits additional type arguments, using TYPE('a) syntax;
   362 
   363 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
   364 creates a new theory node; implicit merge of thms' signatures is
   365 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
   366 transfer:theory->thm->thm in (rare) cases;
   367 
   368 * improved handling of draft signatures / theories; draft thms (and
   369 ctyps, cterms) are automatically promoted to real ones;
   370 
   371 * slightly changed interfaces for oracles: admit many per theory, named
   372 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
   373 
   374 * print_goals: optional output of const types (set show_consts and
   375 show_types);
   376 
   377 * improved output of warnings (###) and errors (***);
   378 
   379 * subgoal_tac displays a warning if the new subgoal has type variables;
   380 
   381 * removed old README and Makefiles;
   382 
   383 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
   384 
   385 * removed obsolete init_pps and init_database;
   386 
   387 * deleted the obsolete tactical STATE, which was declared by
   388     fun STATE tacfun st = tacfun st st;
   389 
   390 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
   391 (which abbreviates $HOME);
   392 
   393 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
   394 use isatool fixseq to adapt your ML programs (this works for fully
   395 qualified references to the Sequence structure only!);
   396 
   397 * use_thy no longer requires writable current directory; it always
   398 reloads .ML *and* .thy file, if either one is out of date;
   399 
   400 
   401 *** Classical Reasoner ***
   402 
   403 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
   404 tactics that use classical reasoning to simplify a subgoal without
   405 splitting it into several subgoals;
   406 
   407 * Safe_tac: like safe_tac but uses the default claset;
   408 
   409 
   410 *** Simplifier ***
   411 
   412 * added simplification meta rules:
   413     (asm_)(full_)simplify: simpset -> thm -> thm;
   414 
   415 * simplifier.ML no longer part of Pure -- has to be loaded by object
   416 logics (again);
   417 
   418 * added prems argument to simplification procedures;
   419 
   420 * HOL, FOL, ZF: added infix function `addsplits':
   421   instead of `<simpset> setloop (split_tac <thms>)'
   422   you can simply write `<simpset> addsplits <thms>'
   423 
   424 
   425 *** Syntax ***
   426 
   427 * TYPE('a) syntax for type reflection terms;
   428 
   429 * no longer handles consts with name "" -- declare as 'syntax' instead;
   430 
   431 * pretty printer: changed order of mixfix annotation preference (again!);
   432 
   433 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
   434 
   435 
   436 *** HOL ***
   437 
   438 * HOL: there is a new splitter `split_asm_tac' that can be used e.g. 
   439   with `addloop' of the simplifier to faciliate case splitting in premises.
   440 
   441 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
   442 
   443 * HOL/Auth: new protocol proofs including some for the Internet
   444   protocol TLS;
   445 
   446 * HOL/Map: new theory of `maps' a la VDM;
   447 
   448 * HOL/simplifier: simplification procedures nat_cancel_sums for
   449 cancelling out common nat summands from =, <, <= (in)equalities, or
   450 differences; simplification procedures nat_cancel_factor for
   451 cancelling common factor from =, <, <= (in)equalities over natural
   452 sums; nat_cancel contains both kinds of procedures, it is installed by
   453 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
   454 
   455 * HOL/simplifier: terms of the form
   456   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
   457   are rewritten to
   458   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
   459   and those of the form
   460   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
   461   are rewritten to
   462   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
   463 
   464 * HOL/datatype
   465   Each datatype `t' now comes with a theorem `split_t_case' of the form
   466 
   467   P(t_case f1 ... fn x) =
   468      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
   469         ...
   470        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
   471      )
   472 
   473   and a theorem `split_t_case_asm' of the form
   474 
   475   P(t_case f1 ... fn x) =
   476     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
   477         ...
   478        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
   479      )
   480   which can be added to a simpset via `addsplits'. The existing theorems
   481   expand_list_case and expand_option_case have been renamed to
   482   split_list_case and split_option_case.
   483 
   484 * HOL/Arithmetic:
   485   - `pred n' is automatically converted to `n-1'.
   486     Users are strongly encouraged not to use `pred' any longer,
   487     because it will disappear altogether at some point.
   488   - Users are strongly encouraged to write "0 < n" rather than
   489     "n ~= 0". Theorems and proof tools have been modified towards this
   490     `standard'.
   491 
   492 * HOL/Lists:
   493   the function "set_of_list" has been renamed "set" (and its theorems too);
   494   the function "nth" now takes its arguments in the reverse order and
   495   has acquired the infix notation "!" as in "xs!n".
   496 
   497 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
   498 
   499 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
   500   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
   501 
   502 * HOL/record: extensible records with schematic structural subtyping
   503 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
   504 still lacks various theorems and concrete record syntax;
   505 
   506 
   507 *** HOLCF ***
   508 
   509 * removed "axioms" and "generated by" sections;
   510 
   511 * replaced "ops" section by extended "consts" section, which is capable of
   512   handling the continuous function space "->" directly;
   513 
   514 * domain package:
   515   . proves theorems immediately and stores them in the theory,
   516   . creates hierachical name space,
   517   . now uses normal mixfix annotations (instead of cinfix...),
   518   . minor changes to some names and values (for consistency),
   519   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
   520   . separator between mutual domain defs: changed "," to "and",
   521   . improved handling of sort constraints;  now they have to
   522     appear on the left-hand side of the equations only;
   523 
   524 * fixed LAM <x,y,zs>.b syntax;
   525 
   526 * added extended adm_tac to simplifier in HOLCF -- can now discharge
   527 adm (%x. P (t x)), where P is chainfinite and t continuous;
   528 
   529 
   530 *** FOL and ZF ***
   531 
   532 * FOL: there is a new splitter `split_asm_tac' that can be used e.g. 
   533   with `addloop' of the simplifier to faciliate case splitting in premises.
   534 
   535 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
   536 in HOL, they strip ALL and --> from proved theorems;
   537 
   538 
   539 
   540 New in Isabelle94-8 (May 1997)
   541 ------------------------------
   542 
   543 *** General Changes ***
   544 
   545 * new utilities to build / run / maintain Isabelle etc. (in parts
   546 still somewhat experimental); old Makefiles etc. still functional;
   547 
   548 * new 'Isabelle System Manual';
   549 
   550 * INSTALL text, together with ./configure and ./build scripts;
   551 
   552 * reimplemented type inference for greater efficiency, better error
   553 messages and clean internal interface;
   554 
   555 * prlim command for dealing with lots of subgoals (an easier way of
   556 setting goals_limit);
   557 
   558 
   559 *** Syntax ***
   560 
   561 * supports alternative (named) syntax tables (parser and pretty
   562 printer); internal interface is provided by add_modesyntax(_i);
   563 
   564 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
   565 be used in conjunction with the Isabelle symbol font; uses the
   566 "symbols" syntax table;
   567 
   568 * added token_translation interface (may translate name tokens in
   569 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
   570 the current print_mode); IMPORTANT: user print translation functions
   571 are responsible for marking newly introduced bounds
   572 (Syntax.mark_boundT);
   573 
   574 * token translations for modes "xterm" and "xterm_color" that display
   575 names in bold, underline etc. or colors (which requires a color
   576 version of xterm);
   577 
   578 * infixes may now be declared with names independent of their syntax;
   579 
   580 * added typed_print_translation (like print_translation, but may
   581 access type of constant);
   582 
   583 
   584 *** Classical Reasoner ***
   585 
   586 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
   587 some limitations.  Blast_tac...
   588   + ignores addss, addbefore, addafter; this restriction is intrinsic
   589   + ignores elimination rules that don't have the correct format
   590 	(the conclusion MUST be a formula variable)
   591   + ignores types, which can make HOL proofs fail
   592   + rules must not require higher-order unification, e.g. apply_type in ZF
   593     [message "Function Var's argument not a bound variable" relates to this]
   594   + its proof strategy is more general but can actually be slower
   595 
   596 * substitution with equality assumptions no longer permutes other
   597 assumptions;
   598 
   599 * minor changes in semantics of addafter (now called addaltern); renamed
   600 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
   601 (and access functions for it);
   602 
   603 * improved combination of classical reasoner and simplifier: 
   604   + functions for handling clasimpsets
   605   + improvement of addss: now the simplifier is called _after_ the
   606     safe steps.
   607   + safe variant of addss called addSss: uses safe simplifications
   608     _during_ the safe steps. It is more complete as it allows multiple 
   609     instantiations of unknowns (e.g. with slow_tac).
   610 
   611 *** Simplifier ***
   612 
   613 * added interface for simplification procedures (functions that
   614 produce *proven* rewrite rules on the fly, depending on current
   615 redex);
   616 
   617 * ordering on terms as parameter (used for ordered rewriting);
   618 
   619 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
   620 
   621 * the solver is now split into a safe and an unsafe part.
   622 This should be invisible for the normal user, except that the
   623 functions setsolver and addsolver have been renamed to setSolver and
   624 addSolver; added safe_asm_full_simp_tac;
   625 
   626 
   627 *** HOL ***
   628 
   629 * a generic induction tactic `induct_tac' which works for all datatypes and
   630 also for type `nat';
   631 
   632 * a generic case distinction tactic `exhaust_tac' which works for all
   633 datatypes and also for type `nat';
   634 
   635 * each datatype comes with a function `size';
   636 
   637 * patterns in case expressions allow tuple patterns as arguments to
   638 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
   639 
   640 * primrec now also works with type nat;
   641 
   642 * recdef: a new declaration form, allows general recursive functions to be
   643 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
   644 
   645 * the constant for negation has been renamed from "not" to "Not" to
   646 harmonize with FOL, ZF, LK, etc.;
   647 
   648 * HOL/ex/LFilter theory of a corecursive "filter" functional for
   649 infinite lists;
   650 
   651 * HOL/Modelcheck demonstrates invocation of model checker oracle;
   652 
   653 * HOL/ex/Ring.thy declares cring_simp, which solves equational
   654 problems in commutative rings, using axiomatic type classes for + and *;
   655 
   656 * more examples in HOL/MiniML and HOL/Auth;
   657 
   658 * more default rewrite rules for quantifiers, union/intersection;
   659 
   660 * a new constant `arbitrary == @x.False';
   661 
   662 * HOLCF/IOA replaces old HOL/IOA;
   663 
   664 * HOLCF changes: derived all rules and arities 
   665   + axiomatic type classes instead of classes 
   666   + typedef instead of faking type definitions
   667   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
   668   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
   669   + eliminated the types void, one, tr
   670   + use unit lift and bool lift (with translations) instead of one and tr
   671   + eliminated blift from Lift3.thy (use Def instead of blift)
   672   all eliminated rules are derived as theorems --> no visible changes ;
   673 
   674 
   675 *** ZF ***
   676 
   677 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
   678 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
   679 as ZF_cs addSIs [equalityI];
   680 
   681 
   682 
   683 New in Isabelle94-7 (November 96)
   684 ---------------------------------
   685 
   686 * allowing negative levels (as offsets) in prlev and choplev;
   687 
   688 * super-linear speedup for large simplifications;
   689 
   690 * FOL, ZF and HOL now use miniscoping: rewriting pushes
   691 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
   692 FAIL); can suppress it using the command Delsimps (ex_simps @
   693 all_simps); De Morgan laws are also now included, by default;
   694 
   695 * improved printing of ==>  :  ~:
   696 
   697 * new object-logic "Sequents" adds linear logic, while replacing LK
   698 and Modal (thanks to Sara Kalvala);
   699 
   700 * HOL/Auth: correctness proofs for authentication protocols;
   701 
   702 * HOL: new auto_tac combines rewriting and classical reasoning (many
   703 examples on HOL/Auth);
   704 
   705 * HOL: new command AddIffs for declaring theorems of the form P=Q to
   706 the rewriter and classical reasoner simultaneously;
   707 
   708 * function uresult no longer returns theorems in "standard" format;
   709 regain previous version by: val uresult = standard o uresult;
   710 
   711 
   712 
   713 New in Isabelle94-6
   714 -------------------
   715 
   716 * oracles -- these establish an interface between Isabelle and trusted
   717 external reasoners, which may deliver results as theorems;
   718 
   719 * proof objects (in particular record all uses of oracles);
   720 
   721 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
   722 
   723 * "constdefs" section in theory files;
   724 
   725 * "primrec" section (HOL) no longer requires names;
   726 
   727 * internal type "tactic" now simply "thm -> thm Sequence.seq";
   728 
   729 
   730 
   731 New in Isabelle94-5
   732 -------------------
   733 
   734 * reduced space requirements;
   735 
   736 * automatic HTML generation from theories;
   737 
   738 * theory files no longer require "..." (quotes) around most types;
   739 
   740 * new examples, including two proofs of the Church-Rosser theorem;
   741 
   742 * non-curried (1994) version of HOL is no longer distributed;
   743 
   744 
   745 
   746 New in Isabelle94-4
   747 -------------------
   748 
   749 * greatly reduced space requirements;
   750 
   751 * theory files (.thy) no longer require \...\ escapes at line breaks;
   752 
   753 * searchable theorem database (see the section "Retrieving theorems" on 
   754 page 8 of the Reference Manual);
   755 
   756 * new examples, including Grabczewski's monumental case study of the
   757 Axiom of Choice;
   758 
   759 * The previous version of HOL renamed to Old_HOL;
   760 
   761 * The new version of HOL (previously called CHOL) uses a curried syntax 
   762 for functions.  Application looks like f a b instead of f(a,b);
   763 
   764 * Mutually recursive inductive definitions finally work in HOL;
   765 
   766 * In ZF, pattern-matching on tuples is now available in all abstractions and
   767 translates to the operator "split";
   768 
   769 
   770 
   771 New in Isabelle94-3
   772 -------------------
   773 
   774 * new infix operator, addss, allowing the classical reasoner to 
   775 perform simplification at each step of its search.  Example:
   776 	fast_tac (cs addss ss)
   777 
   778 * a new logic, CHOL, the same as HOL, but with a curried syntax 
   779 for functions.  Application looks like f a b instead of f(a,b).  Also pairs 
   780 look like (a,b) instead of <a,b>;
   781 
   782 * PLEASE NOTE: CHOL will eventually replace HOL!
   783 
   784 * In CHOL, pattern-matching on tuples is now available in all abstractions.
   785 It translates to the operator "split".  A new theory of integers is available;
   786 
   787 * In ZF, integer numerals now denote two's-complement binary integers.
   788 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
   789 
   790 * Many new examples: I/O automata, Church-Rosser theorem, equivalents 
   791 of the Axiom of Choice;
   792 
   793 
   794 
   795 New in Isabelle94-2
   796 -------------------
   797 
   798 * Significantly faster resolution;  
   799 
   800 * the different sections in a .thy file can now be mixed and repeated
   801 freely;
   802 
   803 * Database of theorems for FOL, HOL and ZF.  New
   804 commands including qed, qed_goal and bind_thm store theorems in the database.
   805 
   806 * Simple database queries: return a named theorem (get_thm) or all theorems of
   807 a given theory (thms_of), or find out what theory a theorem was proved in
   808 (theory_of_thm);
   809 
   810 * Bugs fixed in the inductive definition and datatype packages;
   811 
   812 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
   813 and HOL_dup_cs obsolete;
   814 
   815 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
   816 have been removed;
   817 
   818 * Simpler definition of function space in ZF;
   819 
   820 * new results about cardinal and ordinal arithmetic in ZF;
   821 
   822 * 'subtype' facility in HOL for introducing new types as subsets of existing
   823 types;
   824 
   825 
   826 $Id$