NEWS
author wenzelm
Thu Oct 22 20:13:21 1998 +0200 (1998-10-22)
changeset 5731 f84dc3b811e9
parent 5726 5de7e399ec88
child 5781 d37380544c39
permissions -rw-r--r--
current_goals_markers;
     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 automated proof tools;
    11 
    12 * HOL: major changes to the inductive and datatype packages, including
    13 some minor incompatibilities of theory syntax;
    14 
    15 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
    16 called `inj_on';
    17 
    18 * HOL: removed duplicate thms in Arith:
    19   less_imp_add_less  should be replaced by  trans_less_add1
    20   le_imp_add_le      should be replaced by  trans_le_add1
    21 
    22 * HOL: unary minus is now overloaded (new type constraints may be
    23 required);
    24 
    25 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
    26 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
    27 now taken as an integer constant.
    28 
    29 * Pure: ML function 'theory_of' renamed to 'theory';
    30 
    31 
    32 *** Proof tools ***
    33 
    34 * Simplifier:
    35   1. Asm_full_simp_tac is now more aggressive.
    36      1. It will sometimes reorient premises if that increases their power to
    37         simplify.
    38      2. It does no longer proceed strictly from left to right but may also
    39         rotate premises to achieve further simplification.
    40      For compatibility reasons there is now Asm_lr_simp_tac which is like the
    41      old Asm_full_simp_tac in that it does not rotate premises.
    42   2. The simplifier now knows a little bit about nat-arithmetic.
    43 
    44 * Classical reasoner: wrapper mechanism for the classical reasoner now
    45 allows for selected deletion of wrappers, by introduction of names for
    46 wrapper functionals.  This implies that addbefore, addSbefore,
    47 addaltern, and addSaltern now take a pair (name, tactic) as argument,
    48 and that adding two tactics with the same name overwrites the first
    49 one (emitting a warning).
    50   type wrapper = (int -> tactic) -> (int -> tactic)
    51   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
    52   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
    53   delWrapper, delSWrapper: claset *  string            -> claset
    54   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
    55 
    56 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
    57 semantics; addbefore now affects only the unsafe part of step_tac
    58 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
    59 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
    60 by Force_tac;
    61 
    62 * Classical reasoner: setwrapper to setWrapper and compwrapper to
    63 compWrapper; added safe wrapper (and access functions for it);
    64 
    65 * HOL/split_all_tac is now much faster and fails if there is nothing
    66 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
    67 and the names of the automatically generated variables have changed.
    68 split_all_tac has moved within claset() from unsafe wrappers to safe
    69 wrappers, which means that !!-bound variables are split much more
    70 aggressively, and safe_tac and clarify_tac now split such variables.
    71 If this splitting is not appropriate, use delSWrapper "split_all_tac".
    72 Note: the same holds for record_split_tac, which does the job of
    73 split_all_tac for record fields.
    74 
    75 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
    76 permanently to the default simpset using Addsplits just like
    77 Addsimps. They can be removed via Delsplits just like
    78 Delsimps. Lower-case versions are also available.
    79 
    80 * HOL/Simplifier: The rule split_if is now part of the default
    81 simpset. This means that the simplifier will eliminate all occurrences
    82 of if-then-else in the conclusion of a goal. To prevent this, you can
    83 either remove split_if completely from the default simpset by
    84 `Delsplits [split_if]' or remove it in a specific call of the
    85 simplifier using `... delsplits [split_if]'.  You can also add/delete
    86 other case splitting rules to/from the default simpset: every datatype
    87 generates suitable rules `split_t_case' and `split_t_case_asm' (where
    88 t is the name of the datatype).
    89 
    90 * Classical reasoner / Simplifier combination: new force_tac (and
    91 derivatives Force_tac, force) combines rewriting and classical
    92 reasoning (and whatever other tools) similarly to auto_tac, but is
    93 aimed to solve the given subgoal completely.
    94 
    95 
    96 *** General ***
    97 
    98 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
    99 and `goalw': the theory is no longer needed as an explicit argument -
   100 the current theory context is used; assumptions are no longer returned
   101 at the ML-level unless one of them starts with ==> or !!; it is
   102 recommended to convert to these new commands using isatool fixgoal
   103 (backup your sources first!);
   104 
   105 * new top-level commands 'thm' and 'thms' for retrieving theorems from
   106 the current theory context, and 'theory' to lookup stored theories;
   107 
   108 * new theory section 'locale' for declaring constants, assumptions and
   109 definitions that have local scope;
   110 
   111 * new theory section 'nonterminals' for purely syntactic types;
   112 
   113 * new theory section 'setup' for generic ML setup functions
   114 (e.g. package initialization);
   115 
   116 * the distribution now includes Isabelle icons: see
   117 lib/logo/isabelle-{small,tiny}.xpm;
   118 
   119 * isatool install - install binaries with absolute references to
   120 ISABELLE_HOME/bin;
   121 
   122 * isatool logo -- create instances of the Isabelle logo (as EPS);
   123 
   124 * print mode 'emacs' reserved for Isamode;
   125 
   126 * support multiple print (ast) translations per constant name;
   127 
   128 
   129 *** HOL ***
   130 
   131 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
   132 
   133 * HOL/inductive package reorganized and improved: now supports mutual
   134 definitions such as
   135 
   136   inductive EVEN ODD
   137     intrs
   138       null "0 : EVEN"
   139       oddI "n : EVEN ==> Suc n : ODD"
   140       evenI "n : ODD ==> Suc n : EVEN"
   141 
   142 new theorem list "elims" contains an elimination rule for each of the
   143 recursive sets; inductive definitions now handle disjunctive premises
   144 correctly (also ZF);
   145 
   146 INCOMPATIBILITIES: requires Inductive as an ancestor; component
   147 "mutual_induct" no longer exists - the induction rule is always
   148 contained in "induct";
   149 
   150 
   151 * HOL/datatype package re-implemented and greatly improved: now
   152 supports mutually recursive datatypes such as
   153 
   154   datatype
   155     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
   156             | SUM ('a aexp) ('a aexp)
   157             | DIFF ('a aexp) ('a aexp)
   158             | NUM 'a
   159   and
   160     'a bexp = LESS ('a aexp) ('a aexp)
   161             | AND ('a bexp) ('a bexp)
   162             | OR ('a bexp) ('a bexp)
   163 
   164 as well as indirectly recursive datatypes such as
   165 
   166   datatype
   167     ('a, 'b) term = Var 'a
   168                   | App 'b ((('a, 'b) term) list)
   169 
   170 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
   171 induction on mutually / indirectly recursive datatypes.
   172 
   173 Primrec equations are now stored in theory and can be accessed via
   174 <function_name>.simps.
   175 
   176 INCOMPATIBILITIES:
   177 
   178   - Theories using datatypes must now have theory Datatype as an
   179     ancestor.
   180   - The specific <typename>.induct_tac no longer exists - use the
   181     generic induct_tac instead.
   182   - natE has been renamed to nat.exhaust - use exhaust_tac
   183     instead of res_inst_tac ... natE. Note that the variable
   184     names in nat.exhaust differ from the names in natE, this
   185     may cause some "fragile" proofs to fail.
   186   - The theorems split_<typename>_case and split_<typename>_case_asm
   187     have been renamed to <typename>.split and <typename>.split_asm.
   188   - Since default sorts of type variables are now handled correctly,
   189     some datatype definitions may have to be annotated with explicit
   190     sort constraints.
   191   - Primrec definitions no longer require function name and type
   192     of recursive argument.
   193 
   194 Consider using isatool fixdatatype to adapt your theories and proof
   195 scripts to the new package (backup your sources first!).
   196 
   197 
   198 * HOL/record package: considerably improved implementation; now
   199 includes concrete syntax for record types, terms, updates; theorems
   200 for surjective pairing and splitting !!-bound record variables; proof
   201 support is as follows:
   202 
   203   1) standard conversions (selectors or updates applied to record
   204 constructor terms) are part of the standard simpset;
   205 
   206   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
   207 made part of standard simpset and claset via addIffs;
   208 
   209   3) a tactic for record field splitting (record_split_tac) is part of
   210 the standard claset (addSWrapper);
   211 
   212 To get a better idea about these rules you may retrieve them via
   213 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
   214 the name of your record type.
   215 
   216 The split tactic 3) conceptually simplifies by the following rule:
   217 
   218   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
   219 
   220 Thus any record variable that is bound by meta-all will automatically
   221 blow up into some record constructor term, consequently the
   222 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
   223 solve record problems automatically.
   224 
   225 
   226 * reorganized the main HOL image: HOL/Integ and String loaded by
   227 default; theory Main includes everything;
   228 
   229 * automatic simplification of integer sums and comparisons, using cancellation;
   230 
   231 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
   232 
   233 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
   234 
   235 * many new identities for unions, intersections, set difference, etc.;
   236 
   237 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
   238 called split_if, split_split, split_sum_case and split_nat_case (to go
   239 with add/delsplits);
   240 
   241 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
   242 (?x::unit) = (); this is made part of the default simpset, which COULD
   243 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
   244 'Delsimprocs [unit_eq_proc];' as last resort); also note that
   245 unit_abs_eta_conv is added in order to counter the effect of
   246 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
   247 %u.f();
   248 
   249 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
   250 makes more sense);
   251 
   252 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   253   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   254   disjointness reasoning but breaking a few old proofs.
   255 
   256 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
   257 to 'converse' from 'inverse' (for compatibility with ZF and some
   258 literature);
   259 
   260 * HOL/recdef can now declare non-recursive functions, with {} supplied as
   261 the well-founded relation;
   262 
   263 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
   264     Compl A.  The "Compl" syntax remains available as input syntax for this
   265     release ONLY.
   266 
   267 * HOL/Update: new theory of function updates:
   268     f(a:=b) == %x. if x=a then b else f x
   269 may also be iterated as in f(a:=b,c:=d,...);
   270 
   271 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
   272 
   273 * HOL/List:
   274   - new function list_update written xs[i:=v] that updates the i-th
   275     list position. May also be iterated as in xs[i:=a,j:=b,...].
   276   - new function `upt' written [i..j(] which generates the list
   277     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
   278     bound write [i..j], which is a shorthand for [i..j+1(].
   279   - new lexicographic orderings and corresponding wellfoundedness theorems.
   280 
   281 * HOL/Arith:
   282   - removed 'pred' (predecessor) function;
   283   - generalized some theorems about n-1;
   284   - many new laws about "div" and "mod";
   285   - new laws about greatest common divisors (see theory ex/Primes);
   286 
   287 * HOL/Relation: renamed the relational operator r^-1 "converse"
   288 instead of "inverse";
   289 
   290 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
   291   of the multiset ordering;
   292 
   293 * directory HOL/Real: a construction of the reals using Dedekind cuts
   294   (not included by default);
   295 
   296 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
   297 
   298 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
   299   programs, i.e. different program variables may have different types.
   300 
   301 * calling (stac rew i) now fails if "rew" has no effect on the goal
   302   [previously, this check worked only if the rewrite rule was unconditional]
   303   Now rew can involve either definitions or equalities (either == or =).
   304 
   305 
   306 *** ZF ***
   307 
   308 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
   309   only the theorems proved on ZF.ML;
   310 
   311 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   312   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   313   disjointness reasoning but breaking a few old proofs.
   314 
   315 * ZF/Update: new theory of function updates
   316     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
   317   may also be iterated as in f(a:=b,c:=d,...);
   318 
   319 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
   320 
   321 * calling (stac rew i) now fails if "rew" has no effect on the goal
   322   [previously, this check worked only if the rewrite rule was unconditional]
   323   Now rew can involve either definitions or equalities (either == or =).
   324 
   325 * case_tac provided for compatibility with HOL
   326     (like the old excluded_middle_tac, but with subgoals swapped)
   327 
   328 
   329 *** Internal programming interfaces ***
   330 
   331 * Pure: several new basic modules made available for general use, see
   332 also src/Pure/README;
   333 
   334 * improved the theory data mechanism to support encapsulation (data
   335 kind name replaced by private Object.kind, acting as authorization
   336 key); new type-safe user interface via functor TheoryDataFun; generic
   337 print_data function becomes basically useless;
   338 
   339 * removed global_names compatibility flag -- all theory declarations
   340 are qualified by default;
   341 
   342 * module Pure/Syntax now offers quote / antiquote translation
   343 functions (useful for Hoare logic etc. with implicit dependencies);
   344 see HOL/ex/Antiquote for an example use;
   345 
   346 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
   347 cterm -> thm;
   348 
   349 * new tactical CHANGED_GOAL for checking that a tactic modifies a
   350 subgoal;
   351 
   352 * Display.print_goals function moved to Locale.print_goals;
   353 
   354 * standard print function for goals supports current_goals_markers
   355 variable for marking begin of proof, end of proof, start of goal; the
   356 default is ("", "", ""); setting current_goals_markers := ("<proof>",
   357 "</proof>", "<goal>") causes SGML like tagged proof state printing,
   358 for example;
   359 
   360 
   361 
   362 New in Isabelle98 (January 1998)
   363 --------------------------------
   364 
   365 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   366 
   367 * changed lexical syntax of terms / types: dots made part of long
   368 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
   369 
   370 * simpset (and claset) reference variable replaced by functions
   371 simpset / simpset_ref;
   372 
   373 * no longer supports theory aliases (via merge) and non-trivial
   374 implicit merge of thms' signatures;
   375 
   376 * most internal names of constants changed due to qualified names;
   377 
   378 * changed Pure/Sequence interface (see Pure/seq.ML);
   379 
   380 
   381 *** General Changes ***
   382 
   383 * hierachically structured name spaces (for consts, types, axms, thms
   384 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
   385 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
   386 isatool fixdots ensures space after dots (e.g. "%x. x"); set
   387 long_names for fully qualified output names; NOTE: ML programs
   388 (special tactics, packages etc.) referring to internal names may have
   389 to be adapted to cope with fully qualified names; in case of severe
   390 backward campatibility problems try setting 'global_names' at compile
   391 time to have enrything declared within a flat name space; one may also
   392 fine tune name declarations in theories via the 'global' and 'local'
   393 section;
   394 
   395 * reimplemented the implicit simpset and claset using the new anytype
   396 data filed in signatures; references simpset:simpset ref etc. are
   397 replaced by functions simpset:unit->simpset and
   398 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
   399 to patch your ML files accordingly;
   400 
   401 * HTML output now includes theory graph data for display with Java
   402 applet or isatool browser; data generated automatically via isatool
   403 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
   404 
   405 * defs may now be conditional; improved rewrite_goals_tac to handle
   406 conditional equations;
   407 
   408 * defs now admits additional type arguments, using TYPE('a) syntax;
   409 
   410 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
   411 creates a new theory node; implicit merge of thms' signatures is
   412 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
   413 transfer:theory->thm->thm in (rare) cases;
   414 
   415 * improved handling of draft signatures / theories; draft thms (and
   416 ctyps, cterms) are automatically promoted to real ones;
   417 
   418 * slightly changed interfaces for oracles: admit many per theory, named
   419 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
   420 
   421 * print_goals: optional output of const types (set show_consts and
   422 show_types);
   423 
   424 * improved output of warnings (###) and errors (***);
   425 
   426 * subgoal_tac displays a warning if the new subgoal has type variables;
   427 
   428 * removed old README and Makefiles;
   429 
   430 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
   431 
   432 * removed obsolete init_pps and init_database;
   433 
   434 * deleted the obsolete tactical STATE, which was declared by
   435     fun STATE tacfun st = tacfun st st;
   436 
   437 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
   438 (which abbreviates $HOME);
   439 
   440 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
   441 use isatool fixseq to adapt your ML programs (this works for fully
   442 qualified references to the Sequence structure only!);
   443 
   444 * use_thy no longer requires writable current directory; it always
   445 reloads .ML *and* .thy file, if either one is out of date;
   446 
   447 
   448 *** Classical Reasoner ***
   449 
   450 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
   451 tactics that use classical reasoning to simplify a subgoal without
   452 splitting it into several subgoals;
   453 
   454 * Safe_tac: like safe_tac but uses the default claset;
   455 
   456 
   457 *** Simplifier ***
   458 
   459 * added simplification meta rules:
   460     (asm_)(full_)simplify: simpset -> thm -> thm;
   461 
   462 * simplifier.ML no longer part of Pure -- has to be loaded by object
   463 logics (again);
   464 
   465 * added prems argument to simplification procedures;
   466 
   467 * HOL, FOL, ZF: added infix function `addsplits':
   468   instead of `<simpset> setloop (split_tac <thms>)'
   469   you can simply write `<simpset> addsplits <thms>'
   470 
   471 
   472 *** Syntax ***
   473 
   474 * TYPE('a) syntax for type reflection terms;
   475 
   476 * no longer handles consts with name "" -- declare as 'syntax' instead;
   477 
   478 * pretty printer: changed order of mixfix annotation preference (again!);
   479 
   480 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
   481 
   482 
   483 *** HOL ***
   484 
   485 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
   486   with `addloop' of the simplifier to faciliate case splitting in premises.
   487 
   488 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
   489 
   490 * HOL/Auth: new protocol proofs including some for the Internet
   491   protocol TLS;
   492 
   493 * HOL/Map: new theory of `maps' a la VDM;
   494 
   495 * HOL/simplifier: simplification procedures nat_cancel_sums for
   496 cancelling out common nat summands from =, <, <= (in)equalities, or
   497 differences; simplification procedures nat_cancel_factor for
   498 cancelling common factor from =, <, <= (in)equalities over natural
   499 sums; nat_cancel contains both kinds of procedures, it is installed by
   500 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
   501 
   502 * HOL/simplifier: terms of the form
   503   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
   504   are rewritten to
   505   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
   506   and those of the form
   507   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
   508   are rewritten to
   509   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
   510 
   511 * HOL/datatype
   512   Each datatype `t' now comes with a theorem `split_t_case' of the form
   513 
   514   P(t_case f1 ... fn x) =
   515      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
   516         ...
   517        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
   518      )
   519 
   520   and a theorem `split_t_case_asm' of the form
   521 
   522   P(t_case f1 ... fn x) =
   523     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
   524         ...
   525        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
   526      )
   527   which can be added to a simpset via `addsplits'. The existing theorems
   528   expand_list_case and expand_option_case have been renamed to
   529   split_list_case and split_option_case.
   530 
   531 * HOL/Arithmetic:
   532   - `pred n' is automatically converted to `n-1'.
   533     Users are strongly encouraged not to use `pred' any longer,
   534     because it will disappear altogether at some point.
   535   - Users are strongly encouraged to write "0 < n" rather than
   536     "n ~= 0". Theorems and proof tools have been modified towards this
   537     `standard'.
   538 
   539 * HOL/Lists:
   540   the function "set_of_list" has been renamed "set" (and its theorems too);
   541   the function "nth" now takes its arguments in the reverse order and
   542   has acquired the infix notation "!" as in "xs!n".
   543 
   544 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
   545 
   546 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
   547   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
   548 
   549 * HOL/record: extensible records with schematic structural subtyping
   550 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
   551 still lacks various theorems and concrete record syntax;
   552 
   553 
   554 *** HOLCF ***
   555 
   556 * removed "axioms" and "generated by" sections;
   557 
   558 * replaced "ops" section by extended "consts" section, which is capable of
   559   handling the continuous function space "->" directly;
   560 
   561 * domain package:
   562   . proves theorems immediately and stores them in the theory,
   563   . creates hierachical name space,
   564   . now uses normal mixfix annotations (instead of cinfix...),
   565   . minor changes to some names and values (for consistency),
   566   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
   567   . separator between mutual domain defs: changed "," to "and",
   568   . improved handling of sort constraints;  now they have to
   569     appear on the left-hand side of the equations only;
   570 
   571 * fixed LAM <x,y,zs>.b syntax;
   572 
   573 * added extended adm_tac to simplifier in HOLCF -- can now discharge
   574 adm (%x. P (t x)), where P is chainfinite and t continuous;
   575 
   576 
   577 *** FOL and ZF ***
   578 
   579 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
   580   with `addloop' of the simplifier to faciliate case splitting in premises.
   581 
   582 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
   583 in HOL, they strip ALL and --> from proved theorems;
   584 
   585 
   586 
   587 New in Isabelle94-8 (May 1997)
   588 ------------------------------
   589 
   590 *** General Changes ***
   591 
   592 * new utilities to build / run / maintain Isabelle etc. (in parts
   593 still somewhat experimental); old Makefiles etc. still functional;
   594 
   595 * new 'Isabelle System Manual';
   596 
   597 * INSTALL text, together with ./configure and ./build scripts;
   598 
   599 * reimplemented type inference for greater efficiency, better error
   600 messages and clean internal interface;
   601 
   602 * prlim command for dealing with lots of subgoals (an easier way of
   603 setting goals_limit);
   604 
   605 
   606 *** Syntax ***
   607 
   608 * supports alternative (named) syntax tables (parser and pretty
   609 printer); internal interface is provided by add_modesyntax(_i);
   610 
   611 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
   612 be used in conjunction with the Isabelle symbol font; uses the
   613 "symbols" syntax table;
   614 
   615 * added token_translation interface (may translate name tokens in
   616 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
   617 the current print_mode); IMPORTANT: user print translation functions
   618 are responsible for marking newly introduced bounds
   619 (Syntax.mark_boundT);
   620 
   621 * token translations for modes "xterm" and "xterm_color" that display
   622 names in bold, underline etc. or colors (which requires a color
   623 version of xterm);
   624 
   625 * infixes may now be declared with names independent of their syntax;
   626 
   627 * added typed_print_translation (like print_translation, but may
   628 access type of constant);
   629 
   630 
   631 *** Classical Reasoner ***
   632 
   633 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
   634 some limitations.  Blast_tac...
   635   + ignores addss, addbefore, addafter; this restriction is intrinsic
   636   + ignores elimination rules that don't have the correct format
   637         (the conclusion MUST be a formula variable)
   638   + ignores types, which can make HOL proofs fail
   639   + rules must not require higher-order unification, e.g. apply_type in ZF
   640     [message "Function Var's argument not a bound variable" relates to this]
   641   + its proof strategy is more general but can actually be slower
   642 
   643 * substitution with equality assumptions no longer permutes other
   644 assumptions;
   645 
   646 * minor changes in semantics of addafter (now called addaltern); renamed
   647 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
   648 (and access functions for it);
   649 
   650 * improved combination of classical reasoner and simplifier:
   651   + functions for handling clasimpsets
   652   + improvement of addss: now the simplifier is called _after_ the
   653     safe steps.
   654   + safe variant of addss called addSss: uses safe simplifications
   655     _during_ the safe steps. It is more complete as it allows multiple
   656     instantiations of unknowns (e.g. with slow_tac).
   657 
   658 *** Simplifier ***
   659 
   660 * added interface for simplification procedures (functions that
   661 produce *proven* rewrite rules on the fly, depending on current
   662 redex);
   663 
   664 * ordering on terms as parameter (used for ordered rewriting);
   665 
   666 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
   667 
   668 * the solver is now split into a safe and an unsafe part.
   669 This should be invisible for the normal user, except that the
   670 functions setsolver and addsolver have been renamed to setSolver and
   671 addSolver; added safe_asm_full_simp_tac;
   672 
   673 
   674 *** HOL ***
   675 
   676 * a generic induction tactic `induct_tac' which works for all datatypes and
   677 also for type `nat';
   678 
   679 * a generic case distinction tactic `exhaust_tac' which works for all
   680 datatypes and also for type `nat';
   681 
   682 * each datatype comes with a function `size';
   683 
   684 * patterns in case expressions allow tuple patterns as arguments to
   685 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
   686 
   687 * primrec now also works with type nat;
   688 
   689 * recdef: a new declaration form, allows general recursive functions to be
   690 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
   691 
   692 * the constant for negation has been renamed from "not" to "Not" to
   693 harmonize with FOL, ZF, LK, etc.;
   694 
   695 * HOL/ex/LFilter theory of a corecursive "filter" functional for
   696 infinite lists;
   697 
   698 * HOL/Modelcheck demonstrates invocation of model checker oracle;
   699 
   700 * HOL/ex/Ring.thy declares cring_simp, which solves equational
   701 problems in commutative rings, using axiomatic type classes for + and *;
   702 
   703 * more examples in HOL/MiniML and HOL/Auth;
   704 
   705 * more default rewrite rules for quantifiers, union/intersection;
   706 
   707 * a new constant `arbitrary == @x.False';
   708 
   709 * HOLCF/IOA replaces old HOL/IOA;
   710 
   711 * HOLCF changes: derived all rules and arities
   712   + axiomatic type classes instead of classes
   713   + typedef instead of faking type definitions
   714   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
   715   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
   716   + eliminated the types void, one, tr
   717   + use unit lift and bool lift (with translations) instead of one and tr
   718   + eliminated blift from Lift3.thy (use Def instead of blift)
   719   all eliminated rules are derived as theorems --> no visible changes ;
   720 
   721 
   722 *** ZF ***
   723 
   724 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
   725 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
   726 as ZF_cs addSIs [equalityI];
   727 
   728 
   729 
   730 New in Isabelle94-7 (November 96)
   731 ---------------------------------
   732 
   733 * allowing negative levels (as offsets) in prlev and choplev;
   734 
   735 * super-linear speedup for large simplifications;
   736 
   737 * FOL, ZF and HOL now use miniscoping: rewriting pushes
   738 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
   739 FAIL); can suppress it using the command Delsimps (ex_simps @
   740 all_simps); De Morgan laws are also now included, by default;
   741 
   742 * improved printing of ==>  :  ~:
   743 
   744 * new object-logic "Sequents" adds linear logic, while replacing LK
   745 and Modal (thanks to Sara Kalvala);
   746 
   747 * HOL/Auth: correctness proofs for authentication protocols;
   748 
   749 * HOL: new auto_tac combines rewriting and classical reasoning (many
   750 examples on HOL/Auth);
   751 
   752 * HOL: new command AddIffs for declaring theorems of the form P=Q to
   753 the rewriter and classical reasoner simultaneously;
   754 
   755 * function uresult no longer returns theorems in "standard" format;
   756 regain previous version by: val uresult = standard o uresult;
   757 
   758 
   759 
   760 New in Isabelle94-6
   761 -------------------
   762 
   763 * oracles -- these establish an interface between Isabelle and trusted
   764 external reasoners, which may deliver results as theorems;
   765 
   766 * proof objects (in particular record all uses of oracles);
   767 
   768 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
   769 
   770 * "constdefs" section in theory files;
   771 
   772 * "primrec" section (HOL) no longer requires names;
   773 
   774 * internal type "tactic" now simply "thm -> thm Sequence.seq";
   775 
   776 
   777 
   778 New in Isabelle94-5
   779 -------------------
   780 
   781 * reduced space requirements;
   782 
   783 * automatic HTML generation from theories;
   784 
   785 * theory files no longer require "..." (quotes) around most types;
   786 
   787 * new examples, including two proofs of the Church-Rosser theorem;
   788 
   789 * non-curried (1994) version of HOL is no longer distributed;
   790 
   791 
   792 
   793 New in Isabelle94-4
   794 -------------------
   795 
   796 * greatly reduced space requirements;
   797 
   798 * theory files (.thy) no longer require \...\ escapes at line breaks;
   799 
   800 * searchable theorem database (see the section "Retrieving theorems" on
   801 page 8 of the Reference Manual);
   802 
   803 * new examples, including Grabczewski's monumental case study of the
   804 Axiom of Choice;
   805 
   806 * The previous version of HOL renamed to Old_HOL;
   807 
   808 * The new version of HOL (previously called CHOL) uses a curried syntax
   809 for functions.  Application looks like f a b instead of f(a,b);
   810 
   811 * Mutually recursive inductive definitions finally work in HOL;
   812 
   813 * In ZF, pattern-matching on tuples is now available in all abstractions and
   814 translates to the operator "split";
   815 
   816 
   817 
   818 New in Isabelle94-3
   819 -------------------
   820 
   821 * new infix operator, addss, allowing the classical reasoner to
   822 perform simplification at each step of its search.  Example:
   823         fast_tac (cs addss ss)
   824 
   825 * a new logic, CHOL, the same as HOL, but with a curried syntax
   826 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
   827 look like (a,b) instead of <a,b>;
   828 
   829 * PLEASE NOTE: CHOL will eventually replace HOL!
   830 
   831 * In CHOL, pattern-matching on tuples is now available in all abstractions.
   832 It translates to the operator "split".  A new theory of integers is available;
   833 
   834 * In ZF, integer numerals now denote two's-complement binary integers.
   835 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
   836 
   837 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
   838 of the Axiom of Choice;
   839 
   840 
   841 
   842 New in Isabelle94-2
   843 -------------------
   844 
   845 * Significantly faster resolution;
   846 
   847 * the different sections in a .thy file can now be mixed and repeated
   848 freely;
   849 
   850 * Database of theorems for FOL, HOL and ZF.  New
   851 commands including qed, qed_goal and bind_thm store theorems in the database.
   852 
   853 * Simple database queries: return a named theorem (get_thm) or all theorems of
   854 a given theory (thms_of), or find out what theory a theorem was proved in
   855 (theory_of_thm);
   856 
   857 * Bugs fixed in the inductive definition and datatype packages;
   858 
   859 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
   860 and HOL_dup_cs obsolete;
   861 
   862 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
   863 have been removed;
   864 
   865 * Simpler definition of function space in ZF;
   866 
   867 * new results about cardinal and ordinal arithmetic in ZF;
   868 
   869 * 'subtype' facility in HOL for introducing new types as subsets of existing
   870 types;
   871 
   872 
   873 $Id$