NEWS
author wenzelm
Tue Sep 21 17:26:42 1999 +0200 (1999-09-21 ago)
changeset 7558 08b2d5c94b8a
parent 7492 44b333fb5b80
child 7593 6bc8fa8b4b24
permissions -rw-r--r--
setup for refined facts handling;
Method.bang_sectioned_args / Args.bang_facts;
eliminated asm_simp;
tuned improper methods;
     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: The THEN and ELSE parts of conditional expressions (if P then x else y)
    11 are no longer simplified.  (This allows the simplifier to unfold recursive
    12 functional programs.)  To restore the old behaviour, declare
    13 
    14     Delcongs [if_weak_cong];
    15 
    16 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
    17 complement;
    18 
    19 * HOL: the predicate "inj" is now defined by translation to "inj_on";
    20 
    21 * HOL/typedef: fixed type inference for representing set; type
    22 arguments now have to occur explicitly on the rhs as type constraints;
    23 
    24 * ZF: The con_defs part of an inductive definition may no longer refer
    25 to constants declared in the same theory;
    26 
    27 * HOL, ZF: the function mk_cases, generated by the inductive
    28 definition package, has lost an argument.  To simplify its result, it
    29 uses the default simpset instead of a supplied list of theorems.
    30 
    31 * HOL/List: the constructors of type list are now Nil and Cons;
    32 
    33 
    34 *** Proof tools ***
    35 
    36 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
    37 decision procedure for linear arithmetic. Currently it is used for
    38 types `nat' and `int' in HOL (see below) but can, should and will be
    39 instantiated for other types and logics as well.
    40 
    41 * The simplifier now accepts rewrite rules with flexible heads, eg
    42      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
    43   They are applied like any rule with a non-pattern lhs, i.e. by first-order
    44   matching.
    45 
    46 *** General ***
    47 
    48 * new Isabelle/Isar subsystem provides an alternative to traditional
    49 tactical theorem proving; together with the ProofGeneral/isar user
    50 interface it offers an interactive environment for developing human
    51 readable proof documents (Isar == Intelligible semi-automated
    52 reasoning); see isatool doc isar-ref and
    53 http://isabelle.in.tum.de/Isar/ for more information;
    54 
    55 * native support for Proof General, both for classic Isabelle and
    56 Isabelle/Isar (the latter is slightly better supported and more
    57 robust);
    58 
    59 * Isabelle manuals now also available as PDF;
    60 
    61 * improved browser info generation: better HTML markup (including
    62 colors), graph views in several sizes; isatool usedir now provides a
    63 proper interface for user theories (via -P option);
    64 
    65 * theory loader rewritten from scratch (may not be fully
    66 bug-compatible); old loadpath variable has been replaced by show_path,
    67 add_path, del_path, reset_path functions; new operations such as
    68 update_thy, touch_thy, remove_thy (see also isatool doc ref);
    69 
    70 * improved isatool install: option -k creates KDE application icon,
    71 option -p DIR installs standalone binaries;
    72 
    73 * added ML_PLATFORM setting (useful for cross-platform installations);
    74 more robust handling of platform specific ML images for SML/NJ;
    75 
    76 * path element specification '~~' refers to '$ISABELLE_HOME';
    77 
    78 * in locales, the "assumes" and "defines" parts may be omitted if
    79 empty;
    80 
    81 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
    82 long arrows);
    83 
    84 * new print_mode "HTML";
    85 
    86 * new flag show_tags controls display of tags of theorems (which are
    87 basically just comments that may be attached by some tools);
    88 
    89 * Isamode 2.6 requires patch to accomodate change of Isabelle font
    90 mode and goal output format:
    91 
    92 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
    93 244c244
    94 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
    95 ---
    96 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
    97 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
    98 181c181
    99 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
   100 ---
   101 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
   102 
   103 * function bind_thms stores lists of theorems (cf. bind_thm);
   104 
   105 * new shorthand tactics ftac, eatac, datac, fatac
   106 
   107 *** HOL ***
   108 
   109 ** HOL arithmetic **
   110 
   111 * There are now decision procedures for linear arithmetic over nat and
   112 int:
   113 
   114 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
   115 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
   116 are treated as atomic; subformulae not involving type `nat' or `int'
   117 are ignored; quantified subformulae are ignored unless they are
   118 positive universal or negative existential. The tactic has to be
   119 invoked by hand and can be a little bit slow. In particular, the
   120 running time is exponential in the number of occurrences of `min' and
   121 `max', and `-' on `nat'.
   122 
   123 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
   124 (negated) (in)equalities among the premises and the conclusion into
   125 account (i.e. no compound formulae) and does not know about `min' and
   126 `max', and `-' on `nat'. It is fast and is used automatically by the
   127 simplifier.
   128 
   129 NB: At the moment, these decision procedures do not cope with mixed
   130 nat/int formulae where the two parts interact, such as `m < n ==>
   131 int(m) < int(n)'.
   132 
   133 * HOL/Numeral provides a generic theory of numerals (encoded
   134 efficiently as bit strings); setup for types nat/int/real is in place;
   135 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
   136 int, existing theories and proof scripts may require a few additional
   137 type constraints;
   138 
   139 * integer division and remainder can now be performed on constant
   140 arguments;
   141 
   142 * many properties of integer multiplication, division and remainder
   143 are now available;
   144 
   145 * An interface to the Stanford Validity Checker (SVC) is available through the
   146 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
   147 are proved automatically.  SVC must be installed separately, and its results
   148 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
   149 invocation of the underlying oracle).  For SVC see
   150   http://verify.stanford.edu/SVC
   151 
   152 * IsaMakefile: the HOL-Real target now builds an actual image;
   153 
   154 
   155 ** HOL misc **
   156 
   157 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
   158 -- avoids syntactic ambiguities and treats state, transition, and
   159 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
   160 changed syntax and (many) tactics;
   161 
   162 * HOL/datatype: Now also handles arbitrarily branching datatypes
   163   (using function types) such as
   164 
   165   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
   166 
   167 * HOL/record: record_simproc (part of the default simpset) takes care
   168 of selectors applied to updated records; record_split_tac is no longer
   169 part of the default claset; update_defs may now be removed from the
   170 simpset in many cases; COMPATIBILITY: old behavior achieved by
   171 
   172   claset_ref () := claset() addSWrapper record_split_wrapper;
   173   Delsimprocs [record_simproc]
   174 
   175 * HOL/typedef: fixed type inference for representing set; type
   176 arguments now have to occur explicitly on the rhs as type constraints;
   177 
   178 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
   179 names rather than an ML expression;
   180 
   181 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
   182 supplied later.  Program schemes can be defined, such as
   183     "While B C s = (if B s then While B C (C s) else s)"
   184 where the well-founded relation can be chosen after B and C have been given.
   185 
   186 * HOL/List: the constructors of type list are now Nil and Cons;
   187 INCOMPATIBILITY: while [] and infix # syntax is still there, of
   188 course, ML tools referring to List.list.op # etc. have to be adapted;
   189 
   190 * HOL_quantifiers flag superseded by "HOL" print mode, which is
   191 disabled by default; run isabelle with option -m HOL to get back to
   192 the original Gordon/HOL-style output;
   193 
   194 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
   195 ALL x<=y. P, EX x<y. P, EX x<=y. P;
   196 
   197 * HOL basic syntax simplified (more orthogonal): all variants of
   198 All/Ex now support plain / symbolic / HOL notation; plain syntax for
   199 Eps operator is provided as well: "SOME x. P[x]";
   200 
   201 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
   202 
   203 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
   204 thus available for user theories;
   205 
   206 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
   207 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
   208 time;
   209 
   210 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec several
   211   times and then mp
   212 
   213 
   214 *** LK ***
   215 
   216 * the notation <<...>> is now available as a notation for sequences of
   217 formulas;
   218 
   219 * the simplifier is now installed
   220 
   221 * the axiom system has been generalized (thanks to Soren Heilmann) 
   222 
   223 * the classical reasoner now has a default rule database
   224 
   225 
   226 *** ZF ***
   227 
   228 * new primrec section allows primitive recursive functions to be given
   229 directly (as in HOL) over datatypes and the natural numbers;
   230 
   231 * new tactics induct_tac and exhaust_tac for induction (or case
   232 analysis) over datatypes and the natural numbers;
   233 
   234 * the datatype declaration of type T now defines the recursor T_rec;
   235 
   236 * simplification automatically does freeness reasoning for datatype
   237 constructors;
   238 
   239 * automatic type-inference, with AddTCs command to insert new
   240 type-checking rules;
   241 
   242 * datatype introduction rules are now added as Safe Introduction rules
   243 to the claset;
   244 
   245 * the syntax "if P then x else y" is now available in addition to
   246 if(P,x,y);
   247 
   248 
   249 *** Internal programming interfaces ***
   250 
   251 * structures Vartab / Termtab (instances of TableFun) offer efficient
   252 tables indexed by indexname_ord / term_ord (compatible with aconv);
   253 
   254 * AxClass.axclass_tac lost the theory argument;
   255 
   256 * tuned current_goals_markers semantics: begin / end goal avoids
   257 printing empty lines;
   258 
   259 * removed prs and prs_fn hook, which was broken because it did not
   260 include \n in its semantics, forcing writeln to add one
   261 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
   262 string -> unit if you really want to output text without newline;
   263 
   264 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
   265 plain output, interface builders may have to enable 'isabelle_font'
   266 mode to get Isabelle font glyphs as before;
   267 
   268 * refined token_translation interface; INCOMPATIBILITY: output length
   269 now of type real instead of int;
   270 
   271 * theory loader actions may be traced via new ThyInfo.add_hook
   272 interface (see src/Pure/Thy/thy_info.ML); example application: keep
   273 your own database of information attached to *whole* theories -- as
   274 opposed to intra-theory data slots offered via TheoryDataFun;
   275 
   276 
   277 
   278 New in Isabelle98-1 (October 1998)
   279 ----------------------------------
   280 
   281 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   282 
   283 * several changes of automated proof tools;
   284 
   285 * HOL: major changes to the inductive and datatype packages, including
   286 some minor incompatibilities of theory syntax;
   287 
   288 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
   289 called `inj_on';
   290 
   291 * HOL: removed duplicate thms in Arith:
   292   less_imp_add_less  should be replaced by  trans_less_add1
   293   le_imp_add_le      should be replaced by  trans_le_add1
   294 
   295 * HOL: unary minus is now overloaded (new type constraints may be
   296 required);
   297 
   298 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
   299 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
   300 now taken as an integer constant.
   301 
   302 * Pure: ML function 'theory_of' renamed to 'theory';
   303 
   304 
   305 *** Proof tools ***
   306 
   307 * Simplifier:
   308   1. Asm_full_simp_tac is now more aggressive.
   309      1. It will sometimes reorient premises if that increases their power to
   310         simplify.
   311      2. It does no longer proceed strictly from left to right but may also
   312         rotate premises to achieve further simplification.
   313      For compatibility reasons there is now Asm_lr_simp_tac which is like the
   314      old Asm_full_simp_tac in that it does not rotate premises.
   315   2. The simplifier now knows a little bit about nat-arithmetic.
   316 
   317 * Classical reasoner: wrapper mechanism for the classical reasoner now
   318 allows for selected deletion of wrappers, by introduction of names for
   319 wrapper functionals.  This implies that addbefore, addSbefore,
   320 addaltern, and addSaltern now take a pair (name, tactic) as argument,
   321 and that adding two tactics with the same name overwrites the first
   322 one (emitting a warning).
   323   type wrapper = (int -> tactic) -> (int -> tactic)
   324   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
   325   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
   326   delWrapper, delSWrapper: claset *  string            -> claset
   327   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
   328 
   329 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
   330 semantics; addbefore now affects only the unsafe part of step_tac
   331 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
   332 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
   333 by Force_tac;
   334 
   335 * Classical reasoner: setwrapper to setWrapper and compwrapper to
   336 compWrapper; added safe wrapper (and access functions for it);
   337 
   338 * HOL/split_all_tac is now much faster and fails if there is nothing
   339 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
   340 and the names of the automatically generated variables have changed.
   341 split_all_tac has moved within claset() from unsafe wrappers to safe
   342 wrappers, which means that !!-bound variables are split much more
   343 aggressively, and safe_tac and clarify_tac now split such variables.
   344 If this splitting is not appropriate, use delSWrapper "split_all_tac".
   345 Note: the same holds for record_split_tac, which does the job of
   346 split_all_tac for record fields.
   347 
   348 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
   349 permanently to the default simpset using Addsplits just like
   350 Addsimps. They can be removed via Delsplits just like
   351 Delsimps. Lower-case versions are also available.
   352 
   353 * HOL/Simplifier: The rule split_if is now part of the default
   354 simpset. This means that the simplifier will eliminate all occurrences
   355 of if-then-else in the conclusion of a goal. To prevent this, you can
   356 either remove split_if completely from the default simpset by
   357 `Delsplits [split_if]' or remove it in a specific call of the
   358 simplifier using `... delsplits [split_if]'.  You can also add/delete
   359 other case splitting rules to/from the default simpset: every datatype
   360 generates suitable rules `split_t_case' and `split_t_case_asm' (where
   361 t is the name of the datatype).
   362 
   363 * Classical reasoner / Simplifier combination: new force_tac (and
   364 derivatives Force_tac, force) combines rewriting and classical
   365 reasoning (and whatever other tools) similarly to auto_tac, but is
   366 aimed to solve the given subgoal completely.
   367 
   368 
   369 *** General ***
   370 
   371 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
   372 and `goalw': the theory is no longer needed as an explicit argument -
   373 the current theory context is used; assumptions are no longer returned
   374 at the ML-level unless one of them starts with ==> or !!; it is
   375 recommended to convert to these new commands using isatool fixgoal
   376 (backup your sources first!);
   377 
   378 * new top-level commands 'thm' and 'thms' for retrieving theorems from
   379 the current theory context, and 'theory' to lookup stored theories;
   380 
   381 * new theory section 'locale' for declaring constants, assumptions and
   382 definitions that have local scope;
   383 
   384 * new theory section 'nonterminals' for purely syntactic types;
   385 
   386 * new theory section 'setup' for generic ML setup functions
   387 (e.g. package initialization);
   388 
   389 * the distribution now includes Isabelle icons: see
   390 lib/logo/isabelle-{small,tiny}.xpm;
   391 
   392 * isatool install - install binaries with absolute references to
   393 ISABELLE_HOME/bin;
   394 
   395 * isatool logo -- create instances of the Isabelle logo (as EPS);
   396 
   397 * print mode 'emacs' reserved for Isamode;
   398 
   399 * support multiple print (ast) translations per constant name;
   400 
   401 * theorems involving oracles are now printed with a suffixed [!];
   402 
   403 
   404 *** HOL ***
   405 
   406 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
   407 
   408 * HOL/inductive package reorganized and improved: now supports mutual
   409 definitions such as
   410 
   411   inductive EVEN ODD
   412     intrs
   413       null "0 : EVEN"
   414       oddI "n : EVEN ==> Suc n : ODD"
   415       evenI "n : ODD ==> Suc n : EVEN"
   416 
   417 new theorem list "elims" contains an elimination rule for each of the
   418 recursive sets; inductive definitions now handle disjunctive premises
   419 correctly (also ZF);
   420 
   421 INCOMPATIBILITIES: requires Inductive as an ancestor; component
   422 "mutual_induct" no longer exists - the induction rule is always
   423 contained in "induct";
   424 
   425 
   426 * HOL/datatype package re-implemented and greatly improved: now
   427 supports mutually recursive datatypes such as
   428 
   429   datatype
   430     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
   431             | SUM ('a aexp) ('a aexp)
   432             | DIFF ('a aexp) ('a aexp)
   433             | NUM 'a
   434   and
   435     'a bexp = LESS ('a aexp) ('a aexp)
   436             | AND ('a bexp) ('a bexp)
   437             | OR ('a bexp) ('a bexp)
   438 
   439 as well as indirectly recursive datatypes such as
   440 
   441   datatype
   442     ('a, 'b) term = Var 'a
   443                   | App 'b ((('a, 'b) term) list)
   444 
   445 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
   446 induction on mutually / indirectly recursive datatypes.
   447 
   448 Primrec equations are now stored in theory and can be accessed via
   449 <function_name>.simps.
   450 
   451 INCOMPATIBILITIES:
   452 
   453   - Theories using datatypes must now have theory Datatype as an
   454     ancestor.
   455   - The specific <typename>.induct_tac no longer exists - use the
   456     generic induct_tac instead.
   457   - natE has been renamed to nat.exhaust - use exhaust_tac
   458     instead of res_inst_tac ... natE. Note that the variable
   459     names in nat.exhaust differ from the names in natE, this
   460     may cause some "fragile" proofs to fail.
   461   - The theorems split_<typename>_case and split_<typename>_case_asm
   462     have been renamed to <typename>.split and <typename>.split_asm.
   463   - Since default sorts of type variables are now handled correctly,
   464     some datatype definitions may have to be annotated with explicit
   465     sort constraints.
   466   - Primrec definitions no longer require function name and type
   467     of recursive argument.
   468 
   469 Consider using isatool fixdatatype to adapt your theories and proof
   470 scripts to the new package (backup your sources first!).
   471 
   472 
   473 * HOL/record package: considerably improved implementation; now
   474 includes concrete syntax for record types, terms, updates; theorems
   475 for surjective pairing and splitting !!-bound record variables; proof
   476 support is as follows:
   477 
   478   1) standard conversions (selectors or updates applied to record
   479 constructor terms) are part of the standard simpset;
   480 
   481   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
   482 made part of standard simpset and claset via addIffs;
   483 
   484   3) a tactic for record field splitting (record_split_tac) is part of
   485 the standard claset (addSWrapper);
   486 
   487 To get a better idea about these rules you may retrieve them via
   488 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
   489 the name of your record type.
   490 
   491 The split tactic 3) conceptually simplifies by the following rule:
   492 
   493   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
   494 
   495 Thus any record variable that is bound by meta-all will automatically
   496 blow up into some record constructor term, consequently the
   497 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
   498 solve record problems automatically.
   499 
   500 
   501 * reorganized the main HOL image: HOL/Integ and String loaded by
   502 default; theory Main includes everything;
   503 
   504 * automatic simplification of integer sums and comparisons, using cancellation;
   505 
   506 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
   507 
   508 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
   509 
   510 * many new identities for unions, intersections, set difference, etc.;
   511 
   512 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
   513 called split_if, split_split, split_sum_case and split_nat_case (to go
   514 with add/delsplits);
   515 
   516 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
   517 (?x::unit) = (); this is made part of the default simpset, which COULD
   518 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
   519 'Delsimprocs [unit_eq_proc];' as last resort); also note that
   520 unit_abs_eta_conv is added in order to counter the effect of
   521 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
   522 %u.f();
   523 
   524 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
   525 makes more sense);
   526 
   527 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   528   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   529   disjointness reasoning but breaking a few old proofs.
   530 
   531 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
   532 to 'converse' from 'inverse' (for compatibility with ZF and some
   533 literature);
   534 
   535 * HOL/recdef can now declare non-recursive functions, with {} supplied as
   536 the well-founded relation;
   537 
   538 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
   539     Compl A.  The "Compl" syntax remains available as input syntax for this
   540     release ONLY.
   541 
   542 * HOL/Update: new theory of function updates:
   543     f(a:=b) == %x. if x=a then b else f x
   544 may also be iterated as in f(a:=b,c:=d,...);
   545 
   546 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
   547 
   548 * HOL/List:
   549   - new function list_update written xs[i:=v] that updates the i-th
   550     list position. May also be iterated as in xs[i:=a,j:=b,...].
   551   - new function `upt' written [i..j(] which generates the list
   552     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
   553     bound write [i..j], which is a shorthand for [i..j+1(].
   554   - new lexicographic orderings and corresponding wellfoundedness theorems.
   555 
   556 * HOL/Arith:
   557   - removed 'pred' (predecessor) function;
   558   - generalized some theorems about n-1;
   559   - many new laws about "div" and "mod";
   560   - new laws about greatest common divisors (see theory ex/Primes);
   561 
   562 * HOL/Relation: renamed the relational operator r^-1 "converse"
   563 instead of "inverse";
   564 
   565 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
   566   of the multiset ordering;
   567 
   568 * directory HOL/Real: a construction of the reals using Dedekind cuts
   569   (not included by default);
   570 
   571 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
   572 
   573 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
   574   programs, i.e. different program variables may have different types.
   575 
   576 * calling (stac rew i) now fails if "rew" has no effect on the goal
   577   [previously, this check worked only if the rewrite rule was unconditional]
   578   Now rew can involve either definitions or equalities (either == or =).
   579 
   580 
   581 *** ZF ***
   582 
   583 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
   584   only the theorems proved on ZF.ML;
   585 
   586 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   587   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   588   disjointness reasoning but breaking a few old proofs.
   589 
   590 * ZF/Update: new theory of function updates
   591     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
   592   may also be iterated as in f(a:=b,c:=d,...);
   593 
   594 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
   595 
   596 * calling (stac rew i) now fails if "rew" has no effect on the goal
   597   [previously, this check worked only if the rewrite rule was unconditional]
   598   Now rew can involve either definitions or equalities (either == or =).
   599 
   600 * case_tac provided for compatibility with HOL
   601     (like the old excluded_middle_tac, but with subgoals swapped)
   602 
   603 
   604 *** Internal programming interfaces ***
   605 
   606 * Pure: several new basic modules made available for general use, see
   607 also src/Pure/README;
   608 
   609 * improved the theory data mechanism to support encapsulation (data
   610 kind name replaced by private Object.kind, acting as authorization
   611 key); new type-safe user interface via functor TheoryDataFun; generic
   612 print_data function becomes basically useless;
   613 
   614 * removed global_names compatibility flag -- all theory declarations
   615 are qualified by default;
   616 
   617 * module Pure/Syntax now offers quote / antiquote translation
   618 functions (useful for Hoare logic etc. with implicit dependencies);
   619 see HOL/ex/Antiquote for an example use;
   620 
   621 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
   622 cterm -> thm;
   623 
   624 * new tactical CHANGED_GOAL for checking that a tactic modifies a
   625 subgoal;
   626 
   627 * Display.print_goals function moved to Locale.print_goals;
   628 
   629 * standard print function for goals supports current_goals_markers
   630 variable for marking begin of proof, end of proof, start of goal; the
   631 default is ("", "", ""); setting current_goals_markers := ("<proof>",
   632 "</proof>", "<goal>") causes SGML like tagged proof state printing,
   633 for example;
   634 
   635 
   636 
   637 New in Isabelle98 (January 1998)
   638 --------------------------------
   639 
   640 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   641 
   642 * changed lexical syntax of terms / types: dots made part of long
   643 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
   644 
   645 * simpset (and claset) reference variable replaced by functions
   646 simpset / simpset_ref;
   647 
   648 * no longer supports theory aliases (via merge) and non-trivial
   649 implicit merge of thms' signatures;
   650 
   651 * most internal names of constants changed due to qualified names;
   652 
   653 * changed Pure/Sequence interface (see Pure/seq.ML);
   654 
   655 
   656 *** General Changes ***
   657 
   658 * hierachically structured name spaces (for consts, types, axms, thms
   659 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
   660 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
   661 isatool fixdots ensures space after dots (e.g. "%x. x"); set
   662 long_names for fully qualified output names; NOTE: ML programs
   663 (special tactics, packages etc.) referring to internal names may have
   664 to be adapted to cope with fully qualified names; in case of severe
   665 backward campatibility problems try setting 'global_names' at compile
   666 time to have enrything declared within a flat name space; one may also
   667 fine tune name declarations in theories via the 'global' and 'local'
   668 section;
   669 
   670 * reimplemented the implicit simpset and claset using the new anytype
   671 data filed in signatures; references simpset:simpset ref etc. are
   672 replaced by functions simpset:unit->simpset and
   673 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
   674 to patch your ML files accordingly;
   675 
   676 * HTML output now includes theory graph data for display with Java
   677 applet or isatool browser; data generated automatically via isatool
   678 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
   679 
   680 * defs may now be conditional; improved rewrite_goals_tac to handle
   681 conditional equations;
   682 
   683 * defs now admits additional type arguments, using TYPE('a) syntax;
   684 
   685 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
   686 creates a new theory node; implicit merge of thms' signatures is
   687 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
   688 transfer:theory->thm->thm in (rare) cases;
   689 
   690 * improved handling of draft signatures / theories; draft thms (and
   691 ctyps, cterms) are automatically promoted to real ones;
   692 
   693 * slightly changed interfaces for oracles: admit many per theory, named
   694 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
   695 
   696 * print_goals: optional output of const types (set show_consts and
   697 show_types);
   698 
   699 * improved output of warnings (###) and errors (***);
   700 
   701 * subgoal_tac displays a warning if the new subgoal has type variables;
   702 
   703 * removed old README and Makefiles;
   704 
   705 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
   706 
   707 * removed obsolete init_pps and init_database;
   708 
   709 * deleted the obsolete tactical STATE, which was declared by
   710     fun STATE tacfun st = tacfun st st;
   711 
   712 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
   713 (which abbreviates $HOME);
   714 
   715 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
   716 use isatool fixseq to adapt your ML programs (this works for fully
   717 qualified references to the Sequence structure only!);
   718 
   719 * use_thy no longer requires writable current directory; it always
   720 reloads .ML *and* .thy file, if either one is out of date;
   721 
   722 
   723 *** Classical Reasoner ***
   724 
   725 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
   726 tactics that use classical reasoning to simplify a subgoal without
   727 splitting it into several subgoals;
   728 
   729 * Safe_tac: like safe_tac but uses the default claset;
   730 
   731 
   732 *** Simplifier ***
   733 
   734 * added simplification meta rules:
   735     (asm_)(full_)simplify: simpset -> thm -> thm;
   736 
   737 * simplifier.ML no longer part of Pure -- has to be loaded by object
   738 logics (again);
   739 
   740 * added prems argument to simplification procedures;
   741 
   742 * HOL, FOL, ZF: added infix function `addsplits':
   743   instead of `<simpset> setloop (split_tac <thms>)'
   744   you can simply write `<simpset> addsplits <thms>'
   745 
   746 
   747 *** Syntax ***
   748 
   749 * TYPE('a) syntax for type reflection terms;
   750 
   751 * no longer handles consts with name "" -- declare as 'syntax' instead;
   752 
   753 * pretty printer: changed order of mixfix annotation preference (again!);
   754 
   755 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
   756 
   757 
   758 *** HOL ***
   759 
   760 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
   761   with `addloop' of the simplifier to faciliate case splitting in premises.
   762 
   763 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
   764 
   765 * HOL/Auth: new protocol proofs including some for the Internet
   766   protocol TLS;
   767 
   768 * HOL/Map: new theory of `maps' a la VDM;
   769 
   770 * HOL/simplifier: simplification procedures nat_cancel_sums for
   771 cancelling out common nat summands from =, <, <= (in)equalities, or
   772 differences; simplification procedures nat_cancel_factor for
   773 cancelling common factor from =, <, <= (in)equalities over natural
   774 sums; nat_cancel contains both kinds of procedures, it is installed by
   775 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
   776 
   777 * HOL/simplifier: terms of the form
   778   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
   779   are rewritten to
   780   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
   781   and those of the form
   782   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
   783   are rewritten to
   784   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
   785 
   786 * HOL/datatype
   787   Each datatype `t' now comes with a theorem `split_t_case' of the form
   788 
   789   P(t_case f1 ... fn x) =
   790      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
   791         ...
   792        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
   793      )
   794 
   795   and a theorem `split_t_case_asm' of the form
   796 
   797   P(t_case f1 ... fn x) =
   798     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
   799         ...
   800        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
   801      )
   802   which can be added to a simpset via `addsplits'. The existing theorems
   803   expand_list_case and expand_option_case have been renamed to
   804   split_list_case and split_option_case.
   805 
   806 * HOL/Arithmetic:
   807   - `pred n' is automatically converted to `n-1'.
   808     Users are strongly encouraged not to use `pred' any longer,
   809     because it will disappear altogether at some point.
   810   - Users are strongly encouraged to write "0 < n" rather than
   811     "n ~= 0". Theorems and proof tools have been modified towards this
   812     `standard'.
   813 
   814 * HOL/Lists:
   815   the function "set_of_list" has been renamed "set" (and its theorems too);
   816   the function "nth" now takes its arguments in the reverse order and
   817   has acquired the infix notation "!" as in "xs!n".
   818 
   819 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
   820 
   821 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
   822   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
   823 
   824 * HOL/record: extensible records with schematic structural subtyping
   825 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
   826 still lacks various theorems and concrete record syntax;
   827 
   828 
   829 *** HOLCF ***
   830 
   831 * removed "axioms" and "generated by" sections;
   832 
   833 * replaced "ops" section by extended "consts" section, which is capable of
   834   handling the continuous function space "->" directly;
   835 
   836 * domain package:
   837   . proves theorems immediately and stores them in the theory,
   838   . creates hierachical name space,
   839   . now uses normal mixfix annotations (instead of cinfix...),
   840   . minor changes to some names and values (for consistency),
   841   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
   842   . separator between mutual domain defs: changed "," to "and",
   843   . improved handling of sort constraints;  now they have to
   844     appear on the left-hand side of the equations only;
   845 
   846 * fixed LAM <x,y,zs>.b syntax;
   847 
   848 * added extended adm_tac to simplifier in HOLCF -- can now discharge
   849 adm (%x. P (t x)), where P is chainfinite and t continuous;
   850 
   851 
   852 *** FOL and ZF ***
   853 
   854 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
   855   with `addloop' of the simplifier to faciliate case splitting in premises.
   856 
   857 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
   858 in HOL, they strip ALL and --> from proved theorems;
   859 
   860 
   861 
   862 New in Isabelle94-8 (May 1997)
   863 ------------------------------
   864 
   865 *** General Changes ***
   866 
   867 * new utilities to build / run / maintain Isabelle etc. (in parts
   868 still somewhat experimental); old Makefiles etc. still functional;
   869 
   870 * new 'Isabelle System Manual';
   871 
   872 * INSTALL text, together with ./configure and ./build scripts;
   873 
   874 * reimplemented type inference for greater efficiency, better error
   875 messages and clean internal interface;
   876 
   877 * prlim command for dealing with lots of subgoals (an easier way of
   878 setting goals_limit);
   879 
   880 
   881 *** Syntax ***
   882 
   883 * supports alternative (named) syntax tables (parser and pretty
   884 printer); internal interface is provided by add_modesyntax(_i);
   885 
   886 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
   887 be used in conjunction with the Isabelle symbol font; uses the
   888 "symbols" syntax table;
   889 
   890 * added token_translation interface (may translate name tokens in
   891 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
   892 the current print_mode); IMPORTANT: user print translation functions
   893 are responsible for marking newly introduced bounds
   894 (Syntax.mark_boundT);
   895 
   896 * token translations for modes "xterm" and "xterm_color" that display
   897 names in bold, underline etc. or colors (which requires a color
   898 version of xterm);
   899 
   900 * infixes may now be declared with names independent of their syntax;
   901 
   902 * added typed_print_translation (like print_translation, but may
   903 access type of constant);
   904 
   905 
   906 *** Classical Reasoner ***
   907 
   908 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
   909 some limitations.  Blast_tac...
   910   + ignores addss, addbefore, addafter; this restriction is intrinsic
   911   + ignores elimination rules that don't have the correct format
   912         (the conclusion MUST be a formula variable)
   913   + ignores types, which can make HOL proofs fail
   914   + rules must not require higher-order unification, e.g. apply_type in ZF
   915     [message "Function Var's argument not a bound variable" relates to this]
   916   + its proof strategy is more general but can actually be slower
   917 
   918 * substitution with equality assumptions no longer permutes other
   919 assumptions;
   920 
   921 * minor changes in semantics of addafter (now called addaltern); renamed
   922 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
   923 (and access functions for it);
   924 
   925 * improved combination of classical reasoner and simplifier:
   926   + functions for handling clasimpsets
   927   + improvement of addss: now the simplifier is called _after_ the
   928     safe steps.
   929   + safe variant of addss called addSss: uses safe simplifications
   930     _during_ the safe steps. It is more complete as it allows multiple
   931     instantiations of unknowns (e.g. with slow_tac).
   932 
   933 *** Simplifier ***
   934 
   935 * added interface for simplification procedures (functions that
   936 produce *proven* rewrite rules on the fly, depending on current
   937 redex);
   938 
   939 * ordering on terms as parameter (used for ordered rewriting);
   940 
   941 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
   942 
   943 * the solver is now split into a safe and an unsafe part.
   944 This should be invisible for the normal user, except that the
   945 functions setsolver and addsolver have been renamed to setSolver and
   946 addSolver; added safe_asm_full_simp_tac;
   947 
   948 
   949 *** HOL ***
   950 
   951 * a generic induction tactic `induct_tac' which works for all datatypes and
   952 also for type `nat';
   953 
   954 * a generic case distinction tactic `exhaust_tac' which works for all
   955 datatypes and also for type `nat';
   956 
   957 * each datatype comes with a function `size';
   958 
   959 * patterns in case expressions allow tuple patterns as arguments to
   960 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
   961 
   962 * primrec now also works with type nat;
   963 
   964 * recdef: a new declaration form, allows general recursive functions to be
   965 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
   966 
   967 * the constant for negation has been renamed from "not" to "Not" to
   968 harmonize with FOL, ZF, LK, etc.;
   969 
   970 * HOL/ex/LFilter theory of a corecursive "filter" functional for
   971 infinite lists;
   972 
   973 * HOL/Modelcheck demonstrates invocation of model checker oracle;
   974 
   975 * HOL/ex/Ring.thy declares cring_simp, which solves equational
   976 problems in commutative rings, using axiomatic type classes for + and *;
   977 
   978 * more examples in HOL/MiniML and HOL/Auth;
   979 
   980 * more default rewrite rules for quantifiers, union/intersection;
   981 
   982 * a new constant `arbitrary == @x.False';
   983 
   984 * HOLCF/IOA replaces old HOL/IOA;
   985 
   986 * HOLCF changes: derived all rules and arities
   987   + axiomatic type classes instead of classes
   988   + typedef instead of faking type definitions
   989   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
   990   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
   991   + eliminated the types void, one, tr
   992   + use unit lift and bool lift (with translations) instead of one and tr
   993   + eliminated blift from Lift3.thy (use Def instead of blift)
   994   all eliminated rules are derived as theorems --> no visible changes ;
   995 
   996 
   997 *** ZF ***
   998 
   999 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  1000 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  1001 as ZF_cs addSIs [equalityI];
  1002 
  1003 
  1004 
  1005 New in Isabelle94-7 (November 96)
  1006 ---------------------------------
  1007 
  1008 * allowing negative levels (as offsets) in prlev and choplev;
  1009 
  1010 * super-linear speedup for large simplifications;
  1011 
  1012 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  1013 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  1014 FAIL); can suppress it using the command Delsimps (ex_simps @
  1015 all_simps); De Morgan laws are also now included, by default;
  1016 
  1017 * improved printing of ==>  :  ~:
  1018 
  1019 * new object-logic "Sequents" adds linear logic, while replacing LK
  1020 and Modal (thanks to Sara Kalvala);
  1021 
  1022 * HOL/Auth: correctness proofs for authentication protocols;
  1023 
  1024 * HOL: new auto_tac combines rewriting and classical reasoning (many
  1025 examples on HOL/Auth);
  1026 
  1027 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  1028 the rewriter and classical reasoner simultaneously;
  1029 
  1030 * function uresult no longer returns theorems in "standard" format;
  1031 regain previous version by: val uresult = standard o uresult;
  1032 
  1033 
  1034 
  1035 New in Isabelle94-6
  1036 -------------------
  1037 
  1038 * oracles -- these establish an interface between Isabelle and trusted
  1039 external reasoners, which may deliver results as theorems;
  1040 
  1041 * proof objects (in particular record all uses of oracles);
  1042 
  1043 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  1044 
  1045 * "constdefs" section in theory files;
  1046 
  1047 * "primrec" section (HOL) no longer requires names;
  1048 
  1049 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  1050 
  1051 
  1052 
  1053 New in Isabelle94-5
  1054 -------------------
  1055 
  1056 * reduced space requirements;
  1057 
  1058 * automatic HTML generation from theories;
  1059 
  1060 * theory files no longer require "..." (quotes) around most types;
  1061 
  1062 * new examples, including two proofs of the Church-Rosser theorem;
  1063 
  1064 * non-curried (1994) version of HOL is no longer distributed;
  1065 
  1066 
  1067 
  1068 New in Isabelle94-4
  1069 -------------------
  1070 
  1071 * greatly reduced space requirements;
  1072 
  1073 * theory files (.thy) no longer require \...\ escapes at line breaks;
  1074 
  1075 * searchable theorem database (see the section "Retrieving theorems" on
  1076 page 8 of the Reference Manual);
  1077 
  1078 * new examples, including Grabczewski's monumental case study of the
  1079 Axiom of Choice;
  1080 
  1081 * The previous version of HOL renamed to Old_HOL;
  1082 
  1083 * The new version of HOL (previously called CHOL) uses a curried syntax
  1084 for functions.  Application looks like f a b instead of f(a,b);
  1085 
  1086 * Mutually recursive inductive definitions finally work in HOL;
  1087 
  1088 * In ZF, pattern-matching on tuples is now available in all abstractions and
  1089 translates to the operator "split";
  1090 
  1091 
  1092 
  1093 New in Isabelle94-3
  1094 -------------------
  1095 
  1096 * new infix operator, addss, allowing the classical reasoner to
  1097 perform simplification at each step of its search.  Example:
  1098         fast_tac (cs addss ss)
  1099 
  1100 * a new logic, CHOL, the same as HOL, but with a curried syntax
  1101 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  1102 look like (a,b) instead of <a,b>;
  1103 
  1104 * PLEASE NOTE: CHOL will eventually replace HOL!
  1105 
  1106 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  1107 It translates to the operator "split".  A new theory of integers is available;
  1108 
  1109 * In ZF, integer numerals now denote two's-complement binary integers.
  1110 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  1111 
  1112 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  1113 of the Axiom of Choice;
  1114 
  1115 
  1116 
  1117 New in Isabelle94-2
  1118 -------------------
  1119 
  1120 * Significantly faster resolution;
  1121 
  1122 * the different sections in a .thy file can now be mixed and repeated
  1123 freely;
  1124 
  1125 * Database of theorems for FOL, HOL and ZF.  New
  1126 commands including qed, qed_goal and bind_thm store theorems in the database.
  1127 
  1128 * Simple database queries: return a named theorem (get_thm) or all theorems of
  1129 a given theory (thms_of), or find out what theory a theorem was proved in
  1130 (theory_of_thm);
  1131 
  1132 * Bugs fixed in the inductive definition and datatype packages;
  1133 
  1134 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  1135 and HOL_dup_cs obsolete;
  1136 
  1137 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  1138 have been removed;
  1139 
  1140 * Simpler definition of function space in ZF;
  1141 
  1142 * new results about cardinal and ordinal arithmetic in ZF;
  1143 
  1144 * 'subtype' facility in HOL for introducing new types as subsets of existing
  1145 types;
  1146 
  1147 
  1148 $Id$