NEWS
author nipkow
Tue Jul 14 13:30:01 1998 +0200 (1998-07-14)
changeset 5140 216a5dab14b6
parent 5131 dd4ac220b8b4
child 5142 c56aa8b59dc0
permissions -rw-r--r--
inj_on
     1 
     2 Isabelle NEWS -- history of user-visible changes
     3 ================================================
     4 
     5 New in this Isabelle version
     6 ----------------------------
     7 
     8 *** Overview of INCOMPATIBILITIES (see below for more details) ***
     9 
    10 * HOL/inductive requires Inductive.thy as an ancestor;
    11 * `inj_onto' is now called `inj_on' (which makes more sense)
    12 
    13 *** Proof tools ***
    14 
    15 * Simplifier: Asm_full_simp_tac is now more aggressive.
    16   1. It will sometimes reorient premises if that increases their power to
    17      simplify.
    18   2. It does no longer proceed strictly from left to right but may also
    19      rotate premises to achieve further simplification.
    20   For compatibility reasons there is now Asm_lr_simp_tac which is like the
    21   old Asm_full_simp_tac in that it does not rotate premises.
    22 
    23 * Classical reasoner: wrapper mechanism for the classical reasoner now
    24 allows for selected deletion of wrappers, by introduction of names for
    25 wrapper functionals.  This implies that addbefore, addSbefore,
    26 addaltern, and addSaltern now take a pair (name, tactic) as argument,
    27 and that adding two tactics with the same name overwrites the first
    28 one (emitting a warning).
    29   type wrapper = (int -> tactic) -> (int -> tactic)
    30   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
    31   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
    32   delWrapper, delSWrapper: claset *  string            -> claset
    33   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
    34 
    35 * HOL/split_all_tac is now much faster and fails if there is nothing
    36 to split.  Existing (fragile) proofs may require adaption because the
    37 order and the names of the automatically generated variables have
    38 changed.  split_all_tac has moved within claset() from unsafe wrappers
    39 to safe wrappers, which means that !!-bound variables are split much
    40 more aggressively, and safe_tac and clarify_tac now split such
    41 variables.  If this splitting is not appropriate, use delSWrapper
    42 "split_all_tac".
    43 
    44 * HOL/Simplifier:
    45 
    46  - Rewrite rules for case distinctions can now be added permanently to
    47    the default simpset using Addsplits just like Addsimps. They can be
    48    removed via Delsplits just like Delsimps. Lower-case versions are
    49    also available.
    50 
    51  - The rule split_if is now part of the default simpset. This means
    52    that the simplifier will eliminate all occurrences of if-then-else
    53    in the conclusion of a goal. To prevent this, you can either remove
    54    split_if completely from the default simpset by `Delsplits
    55    [split_if]' or remove it in a specific call of the simplifier using
    56    `... delsplits [split_if]'.  You can also add/delete other case
    57    splitting rules to/from the default simpset: every datatype
    58    generates suitable rules `split_t_case' and `split_t_case_asm'
    59    (where t is the name of the datatype).
    60 
    61 * Classical reasoner - Simplifier combination: new force_tac (and
    62 derivatives Force_tac, force) combines rewriting and classical
    63 reasoning (and whatever other tools) similarly to auto_tac, but is
    64 aimed to solve the given subgoal completely;
    65 
    66 
    67 *** General ***
    68 
    69 * new toplevel commands `Goal' and `Goalw' that improve upon `goal'
    70 and `goalw': the theory is no longer needed as an explicit argument -
    71 the current theory context is used; assumptions are no longer returned
    72 at the ML-level unless one of them starts with ==> or !!; it is
    73 recommended to convert to these new commands using isatool fixgoal (as
    74 usual, backup your sources first!);
    75 
    76 * new toplevel commands 'thm' and 'thms' for retrieving theorems from
    77 the current theory context;
    78 
    79 * new theory section 'nonterminals' for purely syntactic types;
    80 
    81 * new theory section 'setup' for generic ML setup functions
    82 (e.g. package initialization);
    83 
    84 * the distribution now includes Isabelle icons: see
    85 lib/logo/isabelle-{small,tiny}.xpm;
    86 
    87 
    88 *** HOL ***
    89 
    90 * reorganized the main HOL image: HOL/Integ and String loaded by
    91 default; theory Main includes everything;
    92 
    93 * added option_map_eq_Some to the default simpset claset;
    94 
    95 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
    96 
    97 * many new identities for unions, intersections, set difference, etc.;
    98 
    99 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
   100 called split_if, split_split, split_sum_case and split_nat_case (to go
   101 with add/delsplits);
   102 
   103 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
   104 (?x::unit) = (); this is made part of the default simpset, which COULD
   105 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
   106 'Delsimprocs [unit_eq_proc];' as last resort);
   107 
   108 * HOL/record package: now includes concrete syntax for record terms
   109 (still lacks important theorems, like surjective pairing and split);
   110 
   111 * HOL/inductive package reorganized and improved: now supports mutual
   112 definitions such as
   113 
   114   inductive EVEN ODD
   115     intrs
   116       null " 0 : EVEN"
   117       oddI "n : EVEN ==> Suc n : ODD"
   118       evenI "n : ODD ==> Suc n : EVEN"
   119 
   120 new component "elims" of the structure created by the package contains
   121 an elimination rule for each of the recursive sets; requires
   122 Inductive.thy as an ancestor; component "mutual_induct" no longer
   123 exists - the induction rule is always contained in "induct"; inductive
   124 definitions now handle disjunctive premises correctly (also ZF);
   125 
   126 * HOL/recdef can now declare non-recursive functions, with {} supplied as
   127 the well-founded relation;
   128 
   129 * HOL/Update: new theory of function updates:
   130     f(a:=b) == %x. if x=a then b else f x
   131 may also be iterated as in f(a:=b,c:=d,...);
   132 
   133 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
   134 
   135 * HOL/List: new function list_update written xs[i:=v] that updates the i-th
   136   list position. May also be iterated as in xs[i:=a,j:=b,...].
   137 
   138 * HOL/Arith:
   139   - removed 'pred' (predecessor) function;
   140   - generalized some theorems about n-1;
   141   - many new laws about "div" and "mod";
   142   - new laws about greatest common divisors (see theory ex/Primes);
   143 
   144 * HOL/Relation: renamed the relational operator r^-1 "converse"
   145 instead of "inverse";
   146 
   147 * directory HOL/Real: a construction of the reals using Dedekind cuts
   148 (not included by default);
   149 
   150 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
   151 
   152 
   153 *** ZF ***
   154 
   155 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
   156 
   157 
   158 *** Internal programming interfaces ***
   159 
   160 * improved the theory data mechanism to support encapsulation (data
   161 kind name replaced by private Object.kind, acting as authorization
   162 key); new type-safe user interface via functor TheoryDataFun;
   163 
   164 * module Pure/Syntax now offers quote / antiquote translation
   165 functions (useful for Hoare logic etc. with implicit dependencies);
   166 
   167 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
   168 cterm -> thm;
   169 
   170 * Pure: several new basic modules made available for general use, see
   171 also src/Pure/README;
   172 
   173 
   174 
   175 New in Isabelle98 (January 1998)
   176 --------------------------------
   177 
   178 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   179 
   180 * changed lexical syntax of terms / types: dots made part of long
   181 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
   182 
   183 * simpset (and claset) reference variable replaced by functions
   184 simpset / simpset_ref;
   185 
   186 * no longer supports theory aliases (via merge) and non-trivial
   187 implicit merge of thms' signatures;
   188 
   189 * most internal names of constants changed due to qualified names;
   190 
   191 * changed Pure/Sequence interface (see Pure/seq.ML);
   192 
   193 
   194 *** General Changes ***
   195 
   196 * hierachically structured name spaces (for consts, types, axms, thms
   197 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
   198 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
   199 isatool fixdots ensures space after dots (e.g. "%x. x"); set
   200 long_names for fully qualified output names; NOTE: ML programs
   201 (special tactics, packages etc.) referring to internal names may have
   202 to be adapted to cope with fully qualified names; in case of severe
   203 backward campatibility problems try setting 'global_names' at compile
   204 time to have enrything declared within a flat name space; one may also
   205 fine tune name declarations in theories via the 'global' and 'local'
   206 section;
   207 
   208 * reimplemented the implicit simpset and claset using the new anytype
   209 data filed in signatures; references simpset:simpset ref etc. are
   210 replaced by functions simpset:unit->simpset and
   211 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
   212 to patch your ML files accordingly;
   213 
   214 * HTML output now includes theory graph data for display with Java
   215 applet or isatool browser; data generated automatically via isatool
   216 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
   217 
   218 * defs may now be conditional; improved rewrite_goals_tac to handle
   219 conditional equations;
   220 
   221 * defs now admits additional type arguments, using TYPE('a) syntax;
   222 
   223 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
   224 creates a new theory node; implicit merge of thms' signatures is
   225 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
   226 transfer:theory->thm->thm in (rare) cases;
   227 
   228 * improved handling of draft signatures / theories; draft thms (and
   229 ctyps, cterms) are automatically promoted to real ones;
   230 
   231 * slightly changed interfaces for oracles: admit many per theory, named
   232 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
   233 
   234 * print_goals: optional output of const types (set show_consts and
   235 show_types);
   236 
   237 * improved output of warnings (###) and errors (***);
   238 
   239 * subgoal_tac displays a warning if the new subgoal has type variables;
   240 
   241 * removed old README and Makefiles;
   242 
   243 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
   244 
   245 * removed obsolete init_pps and init_database;
   246 
   247 * deleted the obsolete tactical STATE, which was declared by
   248     fun STATE tacfun st = tacfun st st;
   249 
   250 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
   251 (which abbreviates $HOME);
   252 
   253 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
   254 use isatool fixseq to adapt your ML programs (this works for fully
   255 qualified references to the Sequence structure only!);
   256 
   257 * use_thy no longer requires writable current directory; it always
   258 reloads .ML *and* .thy file, if either one is out of date;
   259 
   260 
   261 *** Classical Reasoner ***
   262 
   263 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
   264 tactics that use classical reasoning to simplify a subgoal without
   265 splitting it into several subgoals;
   266 
   267 * Safe_tac: like safe_tac but uses the default claset;
   268 
   269 
   270 *** Simplifier ***
   271 
   272 * added simplification meta rules:
   273     (asm_)(full_)simplify: simpset -> thm -> thm;
   274 
   275 * simplifier.ML no longer part of Pure -- has to be loaded by object
   276 logics (again);
   277 
   278 * added prems argument to simplification procedures;
   279 
   280 * HOL, FOL, ZF: added infix function `addsplits':
   281   instead of `<simpset> setloop (split_tac <thms>)'
   282   you can simply write `<simpset> addsplits <thms>'
   283 
   284 
   285 *** Syntax ***
   286 
   287 * TYPE('a) syntax for type reflection terms;
   288 
   289 * no longer handles consts with name "" -- declare as 'syntax' instead;
   290 
   291 * pretty printer: changed order of mixfix annotation preference (again!);
   292 
   293 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
   294 
   295 
   296 *** HOL ***
   297 
   298 * HOL: there is a new splitter `split_asm_tac' that can be used e.g. 
   299   with `addloop' of the simplifier to faciliate case splitting in premises.
   300 
   301 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
   302 
   303 * HOL/Auth: new protocol proofs including some for the Internet
   304   protocol TLS;
   305 
   306 * HOL/Map: new theory of `maps' a la VDM;
   307 
   308 * HOL/simplifier: simplification procedures nat_cancel_sums for
   309 cancelling out common nat summands from =, <, <= (in)equalities, or
   310 differences; simplification procedures nat_cancel_factor for
   311 cancelling common factor from =, <, <= (in)equalities over natural
   312 sums; nat_cancel contains both kinds of procedures, it is installed by
   313 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
   314 
   315 * HOL/simplifier: terms of the form
   316   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
   317   are rewritten to
   318   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
   319   and those of the form
   320   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
   321   are rewritten to
   322   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
   323 
   324 * HOL/datatype
   325   Each datatype `t' now comes with a theorem `split_t_case' of the form
   326 
   327   P(t_case f1 ... fn x) =
   328      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
   329         ...
   330        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
   331      )
   332 
   333   and a theorem `split_t_case_asm' of the form
   334 
   335   P(t_case f1 ... fn x) =
   336     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
   337         ...
   338        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
   339      )
   340   which can be added to a simpset via `addsplits'. The existing theorems
   341   expand_list_case and expand_option_case have been renamed to
   342   split_list_case and split_option_case.
   343 
   344 * HOL/Arithmetic:
   345   - `pred n' is automatically converted to `n-1'.
   346     Users are strongly encouraged not to use `pred' any longer,
   347     because it will disappear altogether at some point.
   348   - Users are strongly encouraged to write "0 < n" rather than
   349     "n ~= 0". Theorems and proof tools have been modified towards this
   350     `standard'.
   351 
   352 * HOL/Lists:
   353   the function "set_of_list" has been renamed "set" (and its theorems too);
   354   the function "nth" now takes its arguments in the reverse order and
   355   has acquired the infix notation "!" as in "xs!n".
   356 
   357 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
   358 
   359 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
   360   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
   361 
   362 * HOL/record: extensible records with schematic structural subtyping
   363 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
   364 still lacks various theorems and concrete record syntax;
   365 
   366 
   367 *** HOLCF ***
   368 
   369 * removed "axioms" and "generated by" sections;
   370 
   371 * replaced "ops" section by extended "consts" section, which is capable of
   372   handling the continuous function space "->" directly;
   373 
   374 * domain package:
   375   . proves theorems immediately and stores them in the theory,
   376   . creates hierachical name space,
   377   . now uses normal mixfix annotations (instead of cinfix...),
   378   . minor changes to some names and values (for consistency),
   379   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
   380   . separator between mutual domain defs: changed "," to "and",
   381   . improved handling of sort constraints;  now they have to
   382     appear on the left-hand side of the equations only;
   383 
   384 * fixed LAM <x,y,zs>.b syntax;
   385 
   386 * added extended adm_tac to simplifier in HOLCF -- can now discharge
   387 adm (%x. P (t x)), where P is chainfinite and t continuous;
   388 
   389 
   390 *** FOL and ZF ***
   391 
   392 * FOL: there is a new splitter `split_asm_tac' that can be used e.g. 
   393   with `addloop' of the simplifier to faciliate case splitting in premises.
   394 
   395 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
   396 in HOL, they strip ALL and --> from proved theorems;
   397 
   398 
   399 
   400 New in Isabelle94-8 (May 1997)
   401 ------------------------------
   402 
   403 *** General Changes ***
   404 
   405 * new utilities to build / run / maintain Isabelle etc. (in parts
   406 still somewhat experimental); old Makefiles etc. still functional;
   407 
   408 * new 'Isabelle System Manual';
   409 
   410 * INSTALL text, together with ./configure and ./build scripts;
   411 
   412 * reimplemented type inference for greater efficiency, better error
   413 messages and clean internal interface;
   414 
   415 * prlim command for dealing with lots of subgoals (an easier way of
   416 setting goals_limit);
   417 
   418 
   419 *** Syntax ***
   420 
   421 * supports alternative (named) syntax tables (parser and pretty
   422 printer); internal interface is provided by add_modesyntax(_i);
   423 
   424 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
   425 be used in conjunction with the Isabelle symbol font; uses the
   426 "symbols" syntax table;
   427 
   428 * added token_translation interface (may translate name tokens in
   429 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
   430 the current print_mode); IMPORTANT: user print translation functions
   431 are responsible for marking newly introduced bounds
   432 (Syntax.mark_boundT);
   433 
   434 * token translations for modes "xterm" and "xterm_color" that display
   435 names in bold, underline etc. or colors (which requires a color
   436 version of xterm);
   437 
   438 * infixes may now be declared with names independent of their syntax;
   439 
   440 * added typed_print_translation (like print_translation, but may
   441 access type of constant);
   442 
   443 
   444 *** Classical Reasoner ***
   445 
   446 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
   447 some limitations.  Blast_tac...
   448   + ignores addss, addbefore, addafter; this restriction is intrinsic
   449   + ignores elimination rules that don't have the correct format
   450 	(the conclusion MUST be a formula variable)
   451   + ignores types, which can make HOL proofs fail
   452   + rules must not require higher-order unification, e.g. apply_type in ZF
   453     [message "Function Var's argument not a bound variable" relates to this]
   454   + its proof strategy is more general but can actually be slower
   455 
   456 * substitution with equality assumptions no longer permutes other
   457 assumptions;
   458 
   459 * minor changes in semantics of addafter (now called addaltern); renamed
   460 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
   461 (and access functions for it);
   462 
   463 * improved combination of classical reasoner and simplifier: 
   464   + functions for handling clasimpsets
   465   + improvement of addss: now the simplifier is called _after_ the
   466     safe steps.
   467   + safe variant of addss called addSss: uses safe simplifications
   468     _during_ the safe steps. It is more complete as it allows multiple 
   469     instantiations of unknowns (e.g. with slow_tac).
   470 
   471 *** Simplifier ***
   472 
   473 * added interface for simplification procedures (functions that
   474 produce *proven* rewrite rules on the fly, depending on current
   475 redex);
   476 
   477 * ordering on terms as parameter (used for ordered rewriting);
   478 
   479 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
   480 
   481 * the solver is now split into a safe and an unsafe part.
   482 This should be invisible for the normal user, except that the
   483 functions setsolver and addsolver have been renamed to setSolver and
   484 addSolver; added safe_asm_full_simp_tac;
   485 
   486 
   487 *** HOL ***
   488 
   489 * a generic induction tactic `induct_tac' which works for all datatypes and
   490 also for type `nat';
   491 
   492 * a generic case distinction tactic `exhaust_tac' which works for all
   493 datatypes and also for type `nat';
   494 
   495 * each datatype comes with a function `size';
   496 
   497 * patterns in case expressions allow tuple patterns as arguments to
   498 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
   499 
   500 * primrec now also works with type nat;
   501 
   502 * recdef: a new declaration form, allows general recursive functions to be
   503 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
   504 
   505 * the constant for negation has been renamed from "not" to "Not" to
   506 harmonize with FOL, ZF, LK, etc.;
   507 
   508 * HOL/ex/LFilter theory of a corecursive "filter" functional for
   509 infinite lists;
   510 
   511 * HOL/Modelcheck demonstrates invocation of model checker oracle;
   512 
   513 * HOL/ex/Ring.thy declares cring_simp, which solves equational
   514 problems in commutative rings, using axiomatic type classes for + and *;
   515 
   516 * more examples in HOL/MiniML and HOL/Auth;
   517 
   518 * more default rewrite rules for quantifiers, union/intersection;
   519 
   520 * a new constant `arbitrary == @x.False';
   521 
   522 * HOLCF/IOA replaces old HOL/IOA;
   523 
   524 * HOLCF changes: derived all rules and arities 
   525   + axiomatic type classes instead of classes 
   526   + typedef instead of faking type definitions
   527   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
   528   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
   529   + eliminated the types void, one, tr
   530   + use unit lift and bool lift (with translations) instead of one and tr
   531   + eliminated blift from Lift3.thy (use Def instead of blift)
   532   all eliminated rules are derived as theorems --> no visible changes ;
   533 
   534 
   535 *** ZF ***
   536 
   537 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
   538 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
   539 as ZF_cs addSIs [equalityI];
   540 
   541 
   542 
   543 New in Isabelle94-7 (November 96)
   544 ---------------------------------
   545 
   546 * allowing negative levels (as offsets) in prlev and choplev;
   547 
   548 * super-linear speedup for large simplifications;
   549 
   550 * FOL, ZF and HOL now use miniscoping: rewriting pushes
   551 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
   552 FAIL); can suppress it using the command Delsimps (ex_simps @
   553 all_simps); De Morgan laws are also now included, by default;
   554 
   555 * improved printing of ==>  :  ~:
   556 
   557 * new object-logic "Sequents" adds linear logic, while replacing LK
   558 and Modal (thanks to Sara Kalvala);
   559 
   560 * HOL/Auth: correctness proofs for authentication protocols;
   561 
   562 * HOL: new auto_tac combines rewriting and classical reasoning (many
   563 examples on HOL/Auth);
   564 
   565 * HOL: new command AddIffs for declaring theorems of the form P=Q to
   566 the rewriter and classical reasoner simultaneously;
   567 
   568 * function uresult no longer returns theorems in "standard" format;
   569 regain previous version by: val uresult = standard o uresult;
   570 
   571 
   572 
   573 New in Isabelle94-6
   574 -------------------
   575 
   576 * oracles -- these establish an interface between Isabelle and trusted
   577 external reasoners, which may deliver results as theorems;
   578 
   579 * proof objects (in particular record all uses of oracles);
   580 
   581 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
   582 
   583 * "constdefs" section in theory files;
   584 
   585 * "primrec" section (HOL) no longer requires names;
   586 
   587 * internal type "tactic" now simply "thm -> thm Sequence.seq";
   588 
   589 
   590 
   591 New in Isabelle94-5
   592 -------------------
   593 
   594 * reduced space requirements;
   595 
   596 * automatic HTML generation from theories;
   597 
   598 * theory files no longer require "..." (quotes) around most types;
   599 
   600 * new examples, including two proofs of the Church-Rosser theorem;
   601 
   602 * non-curried (1994) version of HOL is no longer distributed;
   603 
   604 
   605 
   606 New in Isabelle94-4
   607 -------------------
   608 
   609 * greatly reduced space requirements;
   610 
   611 * theory files (.thy) no longer require \...\ escapes at line breaks;
   612 
   613 * searchable theorem database (see the section "Retrieving theorems" on 
   614 page 8 of the Reference Manual);
   615 
   616 * new examples, including Grabczewski's monumental case study of the
   617 Axiom of Choice;
   618 
   619 * The previous version of HOL renamed to Old_HOL;
   620 
   621 * The new version of HOL (previously called CHOL) uses a curried syntax 
   622 for functions.  Application looks like f a b instead of f(a,b);
   623 
   624 * Mutually recursive inductive definitions finally work in HOL;
   625 
   626 * In ZF, pattern-matching on tuples is now available in all abstractions and
   627 translates to the operator "split";
   628 
   629 
   630 
   631 New in Isabelle94-3
   632 -------------------
   633 
   634 * new infix operator, addss, allowing the classical reasoner to 
   635 perform simplification at each step of its search.  Example:
   636 	fast_tac (cs addss ss)
   637 
   638 * a new logic, CHOL, the same as HOL, but with a curried syntax 
   639 for functions.  Application looks like f a b instead of f(a,b).  Also pairs 
   640 look like (a,b) instead of <a,b>;
   641 
   642 * PLEASE NOTE: CHOL will eventually replace HOL!
   643 
   644 * In CHOL, pattern-matching on tuples is now available in all abstractions.
   645 It translates to the operator "split".  A new theory of integers is available;
   646 
   647 * In ZF, integer numerals now denote two's-complement binary integers.
   648 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
   649 
   650 * Many new examples: I/O automata, Church-Rosser theorem, equivalents 
   651 of the Axiom of Choice;
   652 
   653 
   654 
   655 New in Isabelle94-2
   656 -------------------
   657 
   658 * Significantly faster resolution;  
   659 
   660 * the different sections in a .thy file can now be mixed and repeated
   661 freely;
   662 
   663 * Database of theorems for FOL, HOL and ZF.  New
   664 commands including qed, qed_goal and bind_thm store theorems in the database.
   665 
   666 * Simple database queries: return a named theorem (get_thm) or all theorems of
   667 a given theory (thms_of), or find out what theory a theorem was proved in
   668 (theory_of_thm);
   669 
   670 * Bugs fixed in the inductive definition and datatype packages;
   671 
   672 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
   673 and HOL_dup_cs obsolete;
   674 
   675 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
   676 have been removed;
   677 
   678 * Simpler definition of function space in ZF;
   679 
   680 * new results about cardinal and ordinal arithmetic in ZF;
   681 
   682 * 'subtype' facility in HOL for introducing new types as subsets of existing
   683 types;
   684 
   685 
   686 $Id$