NEWS
author paulson
Wed Nov 18 15:10:46 1998 +0100 (1998-11-18)
changeset 5931 325300576da7
parent 5781 d37380544c39
child 5973 040f6d2af50d
permissions -rw-r--r--
Finally removing "Compl" from HOL
     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 complement
    11 
    12 *** General ***
    13 
    14 * tuned current_goals_markers semantics: begin / end goal avoids
    15 printing empty lines;
    16 
    17 
    18 New in Isabelle98-1 (October 1998)
    19 ----------------------------------
    20 
    21 *** Overview of INCOMPATIBILITIES (see below for more details) ***
    22 
    23 * several changes of automated proof tools;
    24 
    25 * HOL: major changes to the inductive and datatype packages, including
    26 some minor incompatibilities of theory syntax;
    27 
    28 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
    29 called `inj_on';
    30 
    31 * HOL: removed duplicate thms in Arith:
    32   less_imp_add_less  should be replaced by  trans_less_add1
    33   le_imp_add_le      should be replaced by  trans_le_add1
    34 
    35 * HOL: unary minus is now overloaded (new type constraints may be
    36 required);
    37 
    38 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
    39 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
    40 now taken as an integer constant.
    41 
    42 * Pure: ML function 'theory_of' renamed to 'theory';
    43 
    44 
    45 *** Proof tools ***
    46 
    47 * Simplifier:
    48   1. Asm_full_simp_tac is now more aggressive.
    49      1. It will sometimes reorient premises if that increases their power to
    50         simplify.
    51      2. It does no longer proceed strictly from left to right but may also
    52         rotate premises to achieve further simplification.
    53      For compatibility reasons there is now Asm_lr_simp_tac which is like the
    54      old Asm_full_simp_tac in that it does not rotate premises.
    55   2. The simplifier now knows a little bit about nat-arithmetic.
    56 
    57 * Classical reasoner: wrapper mechanism for the classical reasoner now
    58 allows for selected deletion of wrappers, by introduction of names for
    59 wrapper functionals.  This implies that addbefore, addSbefore,
    60 addaltern, and addSaltern now take a pair (name, tactic) as argument,
    61 and that adding two tactics with the same name overwrites the first
    62 one (emitting a warning).
    63   type wrapper = (int -> tactic) -> (int -> tactic)
    64   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
    65   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
    66   delWrapper, delSWrapper: claset *  string            -> claset
    67   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
    68 
    69 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
    70 semantics; addbefore now affects only the unsafe part of step_tac
    71 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
    72 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
    73 by Force_tac;
    74 
    75 * Classical reasoner: setwrapper to setWrapper and compwrapper to
    76 compWrapper; added safe wrapper (and access functions for it);
    77 
    78 * HOL/split_all_tac is now much faster and fails if there is nothing
    79 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
    80 and the names of the automatically generated variables have changed.
    81 split_all_tac has moved within claset() from unsafe wrappers to safe
    82 wrappers, which means that !!-bound variables are split much more
    83 aggressively, and safe_tac and clarify_tac now split such variables.
    84 If this splitting is not appropriate, use delSWrapper "split_all_tac".
    85 Note: the same holds for record_split_tac, which does the job of
    86 split_all_tac for record fields.
    87 
    88 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
    89 permanently to the default simpset using Addsplits just like
    90 Addsimps. They can be removed via Delsplits just like
    91 Delsimps. Lower-case versions are also available.
    92 
    93 * HOL/Simplifier: The rule split_if is now part of the default
    94 simpset. This means that the simplifier will eliminate all occurrences
    95 of if-then-else in the conclusion of a goal. To prevent this, you can
    96 either remove split_if completely from the default simpset by
    97 `Delsplits [split_if]' or remove it in a specific call of the
    98 simplifier using `... delsplits [split_if]'.  You can also add/delete
    99 other case splitting rules to/from the default simpset: every datatype
   100 generates suitable rules `split_t_case' and `split_t_case_asm' (where
   101 t is the name of the datatype).
   102 
   103 * Classical reasoner / Simplifier combination: new force_tac (and
   104 derivatives Force_tac, force) combines rewriting and classical
   105 reasoning (and whatever other tools) similarly to auto_tac, but is
   106 aimed to solve the given subgoal completely.
   107 
   108 
   109 *** General ***
   110 
   111 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
   112 and `goalw': the theory is no longer needed as an explicit argument -
   113 the current theory context is used; assumptions are no longer returned
   114 at the ML-level unless one of them starts with ==> or !!; it is
   115 recommended to convert to these new commands using isatool fixgoal
   116 (backup your sources first!);
   117 
   118 * new top-level commands 'thm' and 'thms' for retrieving theorems from
   119 the current theory context, and 'theory' to lookup stored theories;
   120 
   121 * new theory section 'locale' for declaring constants, assumptions and
   122 definitions that have local scope;
   123 
   124 * new theory section 'nonterminals' for purely syntactic types;
   125 
   126 * new theory section 'setup' for generic ML setup functions
   127 (e.g. package initialization);
   128 
   129 * the distribution now includes Isabelle icons: see
   130 lib/logo/isabelle-{small,tiny}.xpm;
   131 
   132 * isatool install - install binaries with absolute references to
   133 ISABELLE_HOME/bin;
   134 
   135 * isatool logo -- create instances of the Isabelle logo (as EPS);
   136 
   137 * print mode 'emacs' reserved for Isamode;
   138 
   139 * support multiple print (ast) translations per constant name;
   140 
   141 
   142 *** HOL ***
   143 
   144 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
   145 
   146 * HOL/inductive package reorganized and improved: now supports mutual
   147 definitions such as
   148 
   149   inductive EVEN ODD
   150     intrs
   151       null "0 : EVEN"
   152       oddI "n : EVEN ==> Suc n : ODD"
   153       evenI "n : ODD ==> Suc n : EVEN"
   154 
   155 new theorem list "elims" contains an elimination rule for each of the
   156 recursive sets; inductive definitions now handle disjunctive premises
   157 correctly (also ZF);
   158 
   159 INCOMPATIBILITIES: requires Inductive as an ancestor; component
   160 "mutual_induct" no longer exists - the induction rule is always
   161 contained in "induct";
   162 
   163 
   164 * HOL/datatype package re-implemented and greatly improved: now
   165 supports mutually recursive datatypes such as
   166 
   167   datatype
   168     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
   169             | SUM ('a aexp) ('a aexp)
   170             | DIFF ('a aexp) ('a aexp)
   171             | NUM 'a
   172   and
   173     'a bexp = LESS ('a aexp) ('a aexp)
   174             | AND ('a bexp) ('a bexp)
   175             | OR ('a bexp) ('a bexp)
   176 
   177 as well as indirectly recursive datatypes such as
   178 
   179   datatype
   180     ('a, 'b) term = Var 'a
   181                   | App 'b ((('a, 'b) term) list)
   182 
   183 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
   184 induction on mutually / indirectly recursive datatypes.
   185 
   186 Primrec equations are now stored in theory and can be accessed via
   187 <function_name>.simps.
   188 
   189 INCOMPATIBILITIES:
   190 
   191   - Theories using datatypes must now have theory Datatype as an
   192     ancestor.
   193   - The specific <typename>.induct_tac no longer exists - use the
   194     generic induct_tac instead.
   195   - natE has been renamed to nat.exhaust - use exhaust_tac
   196     instead of res_inst_tac ... natE. Note that the variable
   197     names in nat.exhaust differ from the names in natE, this
   198     may cause some "fragile" proofs to fail.
   199   - The theorems split_<typename>_case and split_<typename>_case_asm
   200     have been renamed to <typename>.split and <typename>.split_asm.
   201   - Since default sorts of type variables are now handled correctly,
   202     some datatype definitions may have to be annotated with explicit
   203     sort constraints.
   204   - Primrec definitions no longer require function name and type
   205     of recursive argument.
   206 
   207 Consider using isatool fixdatatype to adapt your theories and proof
   208 scripts to the new package (backup your sources first!).
   209 
   210 
   211 * HOL/record package: considerably improved implementation; now
   212 includes concrete syntax for record types, terms, updates; theorems
   213 for surjective pairing and splitting !!-bound record variables; proof
   214 support is as follows:
   215 
   216   1) standard conversions (selectors or updates applied to record
   217 constructor terms) are part of the standard simpset;
   218 
   219   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
   220 made part of standard simpset and claset via addIffs;
   221 
   222   3) a tactic for record field splitting (record_split_tac) is part of
   223 the standard claset (addSWrapper);
   224 
   225 To get a better idea about these rules you may retrieve them via
   226 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
   227 the name of your record type.
   228 
   229 The split tactic 3) conceptually simplifies by the following rule:
   230 
   231   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
   232 
   233 Thus any record variable that is bound by meta-all will automatically
   234 blow up into some record constructor term, consequently the
   235 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
   236 solve record problems automatically.
   237 
   238 
   239 * reorganized the main HOL image: HOL/Integ and String loaded by
   240 default; theory Main includes everything;
   241 
   242 * automatic simplification of integer sums and comparisons, using cancellation;
   243 
   244 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
   245 
   246 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
   247 
   248 * many new identities for unions, intersections, set difference, etc.;
   249 
   250 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
   251 called split_if, split_split, split_sum_case and split_nat_case (to go
   252 with add/delsplits);
   253 
   254 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
   255 (?x::unit) = (); this is made part of the default simpset, which COULD
   256 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
   257 'Delsimprocs [unit_eq_proc];' as last resort); also note that
   258 unit_abs_eta_conv is added in order to counter the effect of
   259 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
   260 %u.f();
   261 
   262 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
   263 makes more sense);
   264 
   265 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   266   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   267   disjointness reasoning but breaking a few old proofs.
   268 
   269 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
   270 to 'converse' from 'inverse' (for compatibility with ZF and some
   271 literature);
   272 
   273 * HOL/recdef can now declare non-recursive functions, with {} supplied as
   274 the well-founded relation;
   275 
   276 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
   277     Compl A.  The "Compl" syntax remains available as input syntax for this
   278     release ONLY.
   279 
   280 * HOL/Update: new theory of function updates:
   281     f(a:=b) == %x. if x=a then b else f x
   282 may also be iterated as in f(a:=b,c:=d,...);
   283 
   284 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
   285 
   286 * HOL/List:
   287   - new function list_update written xs[i:=v] that updates the i-th
   288     list position. May also be iterated as in xs[i:=a,j:=b,...].
   289   - new function `upt' written [i..j(] which generates the list
   290     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
   291     bound write [i..j], which is a shorthand for [i..j+1(].
   292   - new lexicographic orderings and corresponding wellfoundedness theorems.
   293 
   294 * HOL/Arith:
   295   - removed 'pred' (predecessor) function;
   296   - generalized some theorems about n-1;
   297   - many new laws about "div" and "mod";
   298   - new laws about greatest common divisors (see theory ex/Primes);
   299 
   300 * HOL/Relation: renamed the relational operator r^-1 "converse"
   301 instead of "inverse";
   302 
   303 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
   304   of the multiset ordering;
   305 
   306 * directory HOL/Real: a construction of the reals using Dedekind cuts
   307   (not included by default);
   308 
   309 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
   310 
   311 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
   312   programs, i.e. different program variables may have different types.
   313 
   314 * calling (stac rew i) now fails if "rew" has no effect on the goal
   315   [previously, this check worked only if the rewrite rule was unconditional]
   316   Now rew can involve either definitions or equalities (either == or =).
   317 
   318 
   319 *** ZF ***
   320 
   321 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
   322   only the theorems proved on ZF.ML;
   323 
   324 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   325   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   326   disjointness reasoning but breaking a few old proofs.
   327 
   328 * ZF/Update: new theory of function updates
   329     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
   330   may also be iterated as in f(a:=b,c:=d,...);
   331 
   332 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
   333 
   334 * calling (stac rew i) now fails if "rew" has no effect on the goal
   335   [previously, this check worked only if the rewrite rule was unconditional]
   336   Now rew can involve either definitions or equalities (either == or =).
   337 
   338 * case_tac provided for compatibility with HOL
   339     (like the old excluded_middle_tac, but with subgoals swapped)
   340 
   341 
   342 *** Internal programming interfaces ***
   343 
   344 * Pure: several new basic modules made available for general use, see
   345 also src/Pure/README;
   346 
   347 * improved the theory data mechanism to support encapsulation (data
   348 kind name replaced by private Object.kind, acting as authorization
   349 key); new type-safe user interface via functor TheoryDataFun; generic
   350 print_data function becomes basically useless;
   351 
   352 * removed global_names compatibility flag -- all theory declarations
   353 are qualified by default;
   354 
   355 * module Pure/Syntax now offers quote / antiquote translation
   356 functions (useful for Hoare logic etc. with implicit dependencies);
   357 see HOL/ex/Antiquote for an example use;
   358 
   359 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
   360 cterm -> thm;
   361 
   362 * new tactical CHANGED_GOAL for checking that a tactic modifies a
   363 subgoal;
   364 
   365 * Display.print_goals function moved to Locale.print_goals;
   366 
   367 * standard print function for goals supports current_goals_markers
   368 variable for marking begin of proof, end of proof, start of goal; the
   369 default is ("", "", ""); setting current_goals_markers := ("<proof>",
   370 "</proof>", "<goal>") causes SGML like tagged proof state printing,
   371 for example;
   372 
   373 
   374 
   375 New in Isabelle98 (January 1998)
   376 --------------------------------
   377 
   378 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   379 
   380 * changed lexical syntax of terms / types: dots made part of long
   381 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
   382 
   383 * simpset (and claset) reference variable replaced by functions
   384 simpset / simpset_ref;
   385 
   386 * no longer supports theory aliases (via merge) and non-trivial
   387 implicit merge of thms' signatures;
   388 
   389 * most internal names of constants changed due to qualified names;
   390 
   391 * changed Pure/Sequence interface (see Pure/seq.ML);
   392 
   393 
   394 *** General Changes ***
   395 
   396 * hierachically structured name spaces (for consts, types, axms, thms
   397 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
   398 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
   399 isatool fixdots ensures space after dots (e.g. "%x. x"); set
   400 long_names for fully qualified output names; NOTE: ML programs
   401 (special tactics, packages etc.) referring to internal names may have
   402 to be adapted to cope with fully qualified names; in case of severe
   403 backward campatibility problems try setting 'global_names' at compile
   404 time to have enrything declared within a flat name space; one may also
   405 fine tune name declarations in theories via the 'global' and 'local'
   406 section;
   407 
   408 * reimplemented the implicit simpset and claset using the new anytype
   409 data filed in signatures; references simpset:simpset ref etc. are
   410 replaced by functions simpset:unit->simpset and
   411 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
   412 to patch your ML files accordingly;
   413 
   414 * HTML output now includes theory graph data for display with Java
   415 applet or isatool browser; data generated automatically via isatool
   416 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
   417 
   418 * defs may now be conditional; improved rewrite_goals_tac to handle
   419 conditional equations;
   420 
   421 * defs now admits additional type arguments, using TYPE('a) syntax;
   422 
   423 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
   424 creates a new theory node; implicit merge of thms' signatures is
   425 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
   426 transfer:theory->thm->thm in (rare) cases;
   427 
   428 * improved handling of draft signatures / theories; draft thms (and
   429 ctyps, cterms) are automatically promoted to real ones;
   430 
   431 * slightly changed interfaces for oracles: admit many per theory, named
   432 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
   433 
   434 * print_goals: optional output of const types (set show_consts and
   435 show_types);
   436 
   437 * improved output of warnings (###) and errors (***);
   438 
   439 * subgoal_tac displays a warning if the new subgoal has type variables;
   440 
   441 * removed old README and Makefiles;
   442 
   443 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
   444 
   445 * removed obsolete init_pps and init_database;
   446 
   447 * deleted the obsolete tactical STATE, which was declared by
   448     fun STATE tacfun st = tacfun st st;
   449 
   450 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
   451 (which abbreviates $HOME);
   452 
   453 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
   454 use isatool fixseq to adapt your ML programs (this works for fully
   455 qualified references to the Sequence structure only!);
   456 
   457 * use_thy no longer requires writable current directory; it always
   458 reloads .ML *and* .thy file, if either one is out of date;
   459 
   460 
   461 *** Classical Reasoner ***
   462 
   463 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
   464 tactics that use classical reasoning to simplify a subgoal without
   465 splitting it into several subgoals;
   466 
   467 * Safe_tac: like safe_tac but uses the default claset;
   468 
   469 
   470 *** Simplifier ***
   471 
   472 * added simplification meta rules:
   473     (asm_)(full_)simplify: simpset -> thm -> thm;
   474 
   475 * simplifier.ML no longer part of Pure -- has to be loaded by object
   476 logics (again);
   477 
   478 * added prems argument to simplification procedures;
   479 
   480 * HOL, FOL, ZF: added infix function `addsplits':
   481   instead of `<simpset> setloop (split_tac <thms>)'
   482   you can simply write `<simpset> addsplits <thms>'
   483 
   484 
   485 *** Syntax ***
   486 
   487 * TYPE('a) syntax for type reflection terms;
   488 
   489 * no longer handles consts with name "" -- declare as 'syntax' instead;
   490 
   491 * pretty printer: changed order of mixfix annotation preference (again!);
   492 
   493 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
   494 
   495 
   496 *** HOL ***
   497 
   498 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
   499   with `addloop' of the simplifier to faciliate case splitting in premises.
   500 
   501 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
   502 
   503 * HOL/Auth: new protocol proofs including some for the Internet
   504   protocol TLS;
   505 
   506 * HOL/Map: new theory of `maps' a la VDM;
   507 
   508 * HOL/simplifier: simplification procedures nat_cancel_sums for
   509 cancelling out common nat summands from =, <, <= (in)equalities, or
   510 differences; simplification procedures nat_cancel_factor for
   511 cancelling common factor from =, <, <= (in)equalities over natural
   512 sums; nat_cancel contains both kinds of procedures, it is installed by
   513 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
   514 
   515 * HOL/simplifier: terms of the form
   516   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
   517   are rewritten to
   518   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
   519   and those of the form
   520   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
   521   are rewritten to
   522   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
   523 
   524 * HOL/datatype
   525   Each datatype `t' now comes with a theorem `split_t_case' of the form
   526 
   527   P(t_case f1 ... fn x) =
   528      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
   529         ...
   530        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
   531      )
   532 
   533   and a theorem `split_t_case_asm' of the form
   534 
   535   P(t_case f1 ... fn x) =
   536     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
   537         ...
   538        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
   539      )
   540   which can be added to a simpset via `addsplits'. The existing theorems
   541   expand_list_case and expand_option_case have been renamed to
   542   split_list_case and split_option_case.
   543 
   544 * HOL/Arithmetic:
   545   - `pred n' is automatically converted to `n-1'.
   546     Users are strongly encouraged not to use `pred' any longer,
   547     because it will disappear altogether at some point.
   548   - Users are strongly encouraged to write "0 < n" rather than
   549     "n ~= 0". Theorems and proof tools have been modified towards this
   550     `standard'.
   551 
   552 * HOL/Lists:
   553   the function "set_of_list" has been renamed "set" (and its theorems too);
   554   the function "nth" now takes its arguments in the reverse order and
   555   has acquired the infix notation "!" as in "xs!n".
   556 
   557 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
   558 
   559 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
   560   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
   561 
   562 * HOL/record: extensible records with schematic structural subtyping
   563 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
   564 still lacks various theorems and concrete record syntax;
   565 
   566 
   567 *** HOLCF ***
   568 
   569 * removed "axioms" and "generated by" sections;
   570 
   571 * replaced "ops" section by extended "consts" section, which is capable of
   572   handling the continuous function space "->" directly;
   573 
   574 * domain package:
   575   . proves theorems immediately and stores them in the theory,
   576   . creates hierachical name space,
   577   . now uses normal mixfix annotations (instead of cinfix...),
   578   . minor changes to some names and values (for consistency),
   579   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
   580   . separator between mutual domain defs: changed "," to "and",
   581   . improved handling of sort constraints;  now they have to
   582     appear on the left-hand side of the equations only;
   583 
   584 * fixed LAM <x,y,zs>.b syntax;
   585 
   586 * added extended adm_tac to simplifier in HOLCF -- can now discharge
   587 adm (%x. P (t x)), where P is chainfinite and t continuous;
   588 
   589 
   590 *** FOL and ZF ***
   591 
   592 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
   593   with `addloop' of the simplifier to faciliate case splitting in premises.
   594 
   595 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
   596 in HOL, they strip ALL and --> from proved theorems;
   597 
   598 
   599 
   600 New in Isabelle94-8 (May 1997)
   601 ------------------------------
   602 
   603 *** General Changes ***
   604 
   605 * new utilities to build / run / maintain Isabelle etc. (in parts
   606 still somewhat experimental); old Makefiles etc. still functional;
   607 
   608 * new 'Isabelle System Manual';
   609 
   610 * INSTALL text, together with ./configure and ./build scripts;
   611 
   612 * reimplemented type inference for greater efficiency, better error
   613 messages and clean internal interface;
   614 
   615 * prlim command for dealing with lots of subgoals (an easier way of
   616 setting goals_limit);
   617 
   618 
   619 *** Syntax ***
   620 
   621 * supports alternative (named) syntax tables (parser and pretty
   622 printer); internal interface is provided by add_modesyntax(_i);
   623 
   624 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
   625 be used in conjunction with the Isabelle symbol font; uses the
   626 "symbols" syntax table;
   627 
   628 * added token_translation interface (may translate name tokens in
   629 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
   630 the current print_mode); IMPORTANT: user print translation functions
   631 are responsible for marking newly introduced bounds
   632 (Syntax.mark_boundT);
   633 
   634 * token translations for modes "xterm" and "xterm_color" that display
   635 names in bold, underline etc. or colors (which requires a color
   636 version of xterm);
   637 
   638 * infixes may now be declared with names independent of their syntax;
   639 
   640 * added typed_print_translation (like print_translation, but may
   641 access type of constant);
   642 
   643 
   644 *** Classical Reasoner ***
   645 
   646 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
   647 some limitations.  Blast_tac...
   648   + ignores addss, addbefore, addafter; this restriction is intrinsic
   649   + ignores elimination rules that don't have the correct format
   650         (the conclusion MUST be a formula variable)
   651   + ignores types, which can make HOL proofs fail
   652   + rules must not require higher-order unification, e.g. apply_type in ZF
   653     [message "Function Var's argument not a bound variable" relates to this]
   654   + its proof strategy is more general but can actually be slower
   655 
   656 * substitution with equality assumptions no longer permutes other
   657 assumptions;
   658 
   659 * minor changes in semantics of addafter (now called addaltern); renamed
   660 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
   661 (and access functions for it);
   662 
   663 * improved combination of classical reasoner and simplifier:
   664   + functions for handling clasimpsets
   665   + improvement of addss: now the simplifier is called _after_ the
   666     safe steps.
   667   + safe variant of addss called addSss: uses safe simplifications
   668     _during_ the safe steps. It is more complete as it allows multiple
   669     instantiations of unknowns (e.g. with slow_tac).
   670 
   671 *** Simplifier ***
   672 
   673 * added interface for simplification procedures (functions that
   674 produce *proven* rewrite rules on the fly, depending on current
   675 redex);
   676 
   677 * ordering on terms as parameter (used for ordered rewriting);
   678 
   679 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
   680 
   681 * the solver is now split into a safe and an unsafe part.
   682 This should be invisible for the normal user, except that the
   683 functions setsolver and addsolver have been renamed to setSolver and
   684 addSolver; added safe_asm_full_simp_tac;
   685 
   686 
   687 *** HOL ***
   688 
   689 * a generic induction tactic `induct_tac' which works for all datatypes and
   690 also for type `nat';
   691 
   692 * a generic case distinction tactic `exhaust_tac' which works for all
   693 datatypes and also for type `nat';
   694 
   695 * each datatype comes with a function `size';
   696 
   697 * patterns in case expressions allow tuple patterns as arguments to
   698 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
   699 
   700 * primrec now also works with type nat;
   701 
   702 * recdef: a new declaration form, allows general recursive functions to be
   703 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
   704 
   705 * the constant for negation has been renamed from "not" to "Not" to
   706 harmonize with FOL, ZF, LK, etc.;
   707 
   708 * HOL/ex/LFilter theory of a corecursive "filter" functional for
   709 infinite lists;
   710 
   711 * HOL/Modelcheck demonstrates invocation of model checker oracle;
   712 
   713 * HOL/ex/Ring.thy declares cring_simp, which solves equational
   714 problems in commutative rings, using axiomatic type classes for + and *;
   715 
   716 * more examples in HOL/MiniML and HOL/Auth;
   717 
   718 * more default rewrite rules for quantifiers, union/intersection;
   719 
   720 * a new constant `arbitrary == @x.False';
   721 
   722 * HOLCF/IOA replaces old HOL/IOA;
   723 
   724 * HOLCF changes: derived all rules and arities
   725   + axiomatic type classes instead of classes
   726   + typedef instead of faking type definitions
   727   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
   728   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
   729   + eliminated the types void, one, tr
   730   + use unit lift and bool lift (with translations) instead of one and tr
   731   + eliminated blift from Lift3.thy (use Def instead of blift)
   732   all eliminated rules are derived as theorems --> no visible changes ;
   733 
   734 
   735 *** ZF ***
   736 
   737 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
   738 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
   739 as ZF_cs addSIs [equalityI];
   740 
   741 
   742 
   743 New in Isabelle94-7 (November 96)
   744 ---------------------------------
   745 
   746 * allowing negative levels (as offsets) in prlev and choplev;
   747 
   748 * super-linear speedup for large simplifications;
   749 
   750 * FOL, ZF and HOL now use miniscoping: rewriting pushes
   751 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
   752 FAIL); can suppress it using the command Delsimps (ex_simps @
   753 all_simps); De Morgan laws are also now included, by default;
   754 
   755 * improved printing of ==>  :  ~:
   756 
   757 * new object-logic "Sequents" adds linear logic, while replacing LK
   758 and Modal (thanks to Sara Kalvala);
   759 
   760 * HOL/Auth: correctness proofs for authentication protocols;
   761 
   762 * HOL: new auto_tac combines rewriting and classical reasoning (many
   763 examples on HOL/Auth);
   764 
   765 * HOL: new command AddIffs for declaring theorems of the form P=Q to
   766 the rewriter and classical reasoner simultaneously;
   767 
   768 * function uresult no longer returns theorems in "standard" format;
   769 regain previous version by: val uresult = standard o uresult;
   770 
   771 
   772 
   773 New in Isabelle94-6
   774 -------------------
   775 
   776 * oracles -- these establish an interface between Isabelle and trusted
   777 external reasoners, which may deliver results as theorems;
   778 
   779 * proof objects (in particular record all uses of oracles);
   780 
   781 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
   782 
   783 * "constdefs" section in theory files;
   784 
   785 * "primrec" section (HOL) no longer requires names;
   786 
   787 * internal type "tactic" now simply "thm -> thm Sequence.seq";
   788 
   789 
   790 
   791 New in Isabelle94-5
   792 -------------------
   793 
   794 * reduced space requirements;
   795 
   796 * automatic HTML generation from theories;
   797 
   798 * theory files no longer require "..." (quotes) around most types;
   799 
   800 * new examples, including two proofs of the Church-Rosser theorem;
   801 
   802 * non-curried (1994) version of HOL is no longer distributed;
   803 
   804 
   805 
   806 New in Isabelle94-4
   807 -------------------
   808 
   809 * greatly reduced space requirements;
   810 
   811 * theory files (.thy) no longer require \...\ escapes at line breaks;
   812 
   813 * searchable theorem database (see the section "Retrieving theorems" on
   814 page 8 of the Reference Manual);
   815 
   816 * new examples, including Grabczewski's monumental case study of the
   817 Axiom of Choice;
   818 
   819 * The previous version of HOL renamed to Old_HOL;
   820 
   821 * The new version of HOL (previously called CHOL) uses a curried syntax
   822 for functions.  Application looks like f a b instead of f(a,b);
   823 
   824 * Mutually recursive inductive definitions finally work in HOL;
   825 
   826 * In ZF, pattern-matching on tuples is now available in all abstractions and
   827 translates to the operator "split";
   828 
   829 
   830 
   831 New in Isabelle94-3
   832 -------------------
   833 
   834 * new infix operator, addss, allowing the classical reasoner to
   835 perform simplification at each step of its search.  Example:
   836         fast_tac (cs addss ss)
   837 
   838 * a new logic, CHOL, the same as HOL, but with a curried syntax
   839 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
   840 look like (a,b) instead of <a,b>;
   841 
   842 * PLEASE NOTE: CHOL will eventually replace HOL!
   843 
   844 * In CHOL, pattern-matching on tuples is now available in all abstractions.
   845 It translates to the operator "split".  A new theory of integers is available;
   846 
   847 * In ZF, integer numerals now denote two's-complement binary integers.
   848 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
   849 
   850 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
   851 of the Axiom of Choice;
   852 
   853 
   854 
   855 New in Isabelle94-2
   856 -------------------
   857 
   858 * Significantly faster resolution;
   859 
   860 * the different sections in a .thy file can now be mixed and repeated
   861 freely;
   862 
   863 * Database of theorems for FOL, HOL and ZF.  New
   864 commands including qed, qed_goal and bind_thm store theorems in the database.
   865 
   866 * Simple database queries: return a named theorem (get_thm) or all theorems of
   867 a given theory (thms_of), or find out what theory a theorem was proved in
   868 (theory_of_thm);
   869 
   870 * Bugs fixed in the inductive definition and datatype packages;
   871 
   872 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
   873 and HOL_dup_cs obsolete;
   874 
   875 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
   876 have been removed;
   877 
   878 * Simpler definition of function space in ZF;
   879 
   880 * new results about cardinal and ordinal arithmetic in ZF;
   881 
   882 * 'subtype' facility in HOL for introducing new types as subsets of existing
   883 types;
   884 
   885 
   886 $Id$