NEWS
author wenzelm
Fri Sep 24 17:18:51 1999 +0200 (1999-09-24)
changeset 7595 5f5d575ddac3
parent 7593 6bc8fa8b4b24
child 7619 d78b8b103fd9
permissions -rw-r--r--
* HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
(in Isabelle/Isar) -- by Gertrud Bauer;
     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', `int', and `real' in HOL (see below); it can, should and
    39 will be 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 
    47 *** General ***
    48 
    49 * new Isabelle/Isar subsystem provides an alternative to traditional
    50 tactical theorem proving; together with the ProofGeneral/isar user
    51 interface it offers an interactive environment for developing human
    52 readable proof documents (Isar == Intelligible semi-automated
    53 reasoning); see isatool doc isar-ref and
    54 http://isabelle.in.tum.de/Isar/ for more information;
    55 
    56 * native support for Proof General, both for classic Isabelle and
    57 Isabelle/Isar (the latter is slightly better supported and more
    58 robust);
    59 
    60 * Isabelle manuals now also available as PDF;
    61 
    62 * improved browser info generation: better HTML markup (including
    63 colors), graph views in several sizes; isatool usedir now provides a
    64 proper interface for user theories (via -P option);
    65 
    66 * theory loader rewritten from scratch (may not be fully
    67 bug-compatible); old loadpath variable has been replaced by show_path,
    68 add_path, del_path, reset_path functions; new operations such as
    69 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
    70 isatool doc ref);
    71 
    72 * improved isatool install: option -k creates KDE application icon,
    73 option -p DIR installs standalone binaries;
    74 
    75 * added ML_PLATFORM setting (useful for cross-platform installations);
    76 more robust handling of platform specific ML images for SML/NJ;
    77 
    78 * path element specification '~~' refers to '$ISABELLE_HOME';
    79 
    80 * in locales, the "assumes" and "defines" parts may be omitted if
    81 empty;
    82 
    83 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
    84 long arrows);
    85 
    86 * new print_mode "HTML";
    87 
    88 * new flag show_tags controls display of tags of theorems (which are
    89 basically just comments that may be attached by some tools);
    90 
    91 * Isamode 2.6 requires patch to accomodate change of Isabelle font
    92 mode and goal output format:
    93 
    94 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
    95 244c244
    96 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
    97 ---
    98 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
    99 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
   100 181c181
   101 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
   102 ---
   103 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
   104 
   105 * function bind_thms stores lists of theorems (cf. bind_thm);
   106 
   107 * new shorthand tactics ftac, eatac, datac, fatac;
   108 
   109 * qed (and friends) now accept "" as result name; in that case the
   110 result is not stored, but proper checks and presentation of the result
   111 still apply;
   112 
   113 
   114 *** HOL ***
   115 
   116 ** HOL arithmetic **
   117 
   118 * There are now decision procedures for linear arithmetic over nat and
   119 int:
   120 
   121 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
   122 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
   123 are treated as atomic; subformulae not involving type `nat' or `int'
   124 are ignored; quantified subformulae are ignored unless they are
   125 positive universal or negative existential. The tactic has to be
   126 invoked by hand and can be a little bit slow. In particular, the
   127 running time is exponential in the number of occurrences of `min' and
   128 `max', and `-' on `nat'.
   129 
   130 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
   131 (negated) (in)equalities among the premises and the conclusion into
   132 account (i.e. no compound formulae) and does not know about `min' and
   133 `max', and `-' on `nat'. It is fast and is used automatically by the
   134 simplifier.
   135 
   136 NB: At the moment, these decision procedures do not cope with mixed
   137 nat/int formulae where the two parts interact, such as `m < n ==>
   138 int(m) < int(n)'.
   139 
   140 * HOL/Numeral provides a generic theory of numerals (encoded
   141 efficiently as bit strings); setup for types nat/int/real is in place;
   142 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
   143 int, existing theories and proof scripts may require a few additional
   144 type constraints;
   145 
   146 * integer division and remainder can now be performed on constant
   147 arguments;
   148 
   149 * many properties of integer multiplication, division and remainder
   150 are now available;
   151 
   152 * An interface to the Stanford Validity Checker (SVC) is available through the
   153 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
   154 are proved automatically.  SVC must be installed separately, and its results
   155 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
   156 invocation of the underlying oracle).  For SVC see
   157   http://verify.stanford.edu/SVC
   158 
   159 * IsaMakefile: the HOL-Real target now builds an actual image;
   160 
   161 
   162 ** HOL misc **
   163 
   164 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
   165 (in Isabelle/Isar) -- by Gertrud Bauer;
   166 
   167 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
   168 -- avoids syntactic ambiguities and treats state, transition, and
   169 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
   170 changed syntax and (many) tactics;
   171 
   172 * HOL/datatype: Now also handles arbitrarily branching datatypes
   173   (using function types) such as
   174 
   175   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
   176 
   177 * HOL/record: record_simproc (part of the default simpset) takes care
   178 of selectors applied to updated records; record_split_tac is no longer
   179 part of the default claset; update_defs may now be removed from the
   180 simpset in many cases; COMPATIBILITY: old behavior achieved by
   181 
   182   claset_ref () := claset() addSWrapper record_split_wrapper;
   183   Delsimprocs [record_simproc]
   184 
   185 * HOL/typedef: fixed type inference for representing set; type
   186 arguments now have to occur explicitly on the rhs as type constraints;
   187 
   188 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
   189 names rather than an ML expression;
   190 
   191 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
   192 supplied later.  Program schemes can be defined, such as
   193     "While B C s = (if B s then While B C (C s) else s)"
   194 where the well-founded relation can be chosen after B and C have been given.
   195 
   196 * HOL/List: the constructors of type list are now Nil and Cons;
   197 INCOMPATIBILITY: while [] and infix # syntax is still there, of
   198 course, ML tools referring to List.list.op # etc. have to be adapted;
   199 
   200 * HOL_quantifiers flag superseded by "HOL" print mode, which is
   201 disabled by default; run isabelle with option -m HOL to get back to
   202 the original Gordon/HOL-style output;
   203 
   204 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
   205 ALL x<=y. P, EX x<y. P, EX x<=y. P;
   206 
   207 * HOL basic syntax simplified (more orthogonal): all variants of
   208 All/Ex now support plain / symbolic / HOL notation; plain syntax for
   209 Eps operator is provided as well: "SOME x. P[x]";
   210 
   211 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
   212 
   213 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
   214 thus available for user theories;
   215 
   216 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
   217 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
   218 time;
   219 
   220 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec several
   221   times and then mp
   222 
   223 
   224 *** LK ***
   225 
   226 * the notation <<...>> is now available as a notation for sequences of
   227 formulas;
   228 
   229 * the simplifier is now installed
   230 
   231 * the axiom system has been generalized (thanks to Soren Heilmann) 
   232 
   233 * the classical reasoner now has a default rule database
   234 
   235 
   236 *** ZF ***
   237 
   238 * new primrec section allows primitive recursive functions to be given
   239 directly (as in HOL) over datatypes and the natural numbers;
   240 
   241 * new tactics induct_tac and exhaust_tac for induction (or case
   242 analysis) over datatypes and the natural numbers;
   243 
   244 * the datatype declaration of type T now defines the recursor T_rec;
   245 
   246 * simplification automatically does freeness reasoning for datatype
   247 constructors;
   248 
   249 * automatic type-inference, with AddTCs command to insert new
   250 type-checking rules;
   251 
   252 * datatype introduction rules are now added as Safe Introduction rules
   253 to the claset;
   254 
   255 * the syntax "if P then x else y" is now available in addition to
   256 if(P,x,y);
   257 
   258 
   259 *** Internal programming interfaces ***
   260 
   261 * structures Vartab / Termtab (instances of TableFun) offer efficient
   262 tables indexed by indexname_ord / term_ord (compatible with aconv);
   263 
   264 * AxClass.axclass_tac lost the theory argument;
   265 
   266 * tuned current_goals_markers semantics: begin / end goal avoids
   267 printing empty lines;
   268 
   269 * removed prs and prs_fn hook, which was broken because it did not
   270 include \n in its semantics, forcing writeln to add one
   271 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
   272 string -> unit if you really want to output text without newline;
   273 
   274 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
   275 plain output, interface builders may have to enable 'isabelle_font'
   276 mode to get Isabelle font glyphs as before;
   277 
   278 * refined token_translation interface; INCOMPATIBILITY: output length
   279 now of type real instead of int;
   280 
   281 * theory loader actions may be traced via new ThyInfo.add_hook
   282 interface (see src/Pure/Thy/thy_info.ML); example application: keep
   283 your own database of information attached to *whole* theories -- as
   284 opposed to intra-theory data slots offered via TheoryDataFun;
   285 
   286 
   287 
   288 New in Isabelle98-1 (October 1998)
   289 ----------------------------------
   290 
   291 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   292 
   293 * several changes of automated proof tools;
   294 
   295 * HOL: major changes to the inductive and datatype packages, including
   296 some minor incompatibilities of theory syntax;
   297 
   298 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
   299 called `inj_on';
   300 
   301 * HOL: removed duplicate thms in Arith:
   302   less_imp_add_less  should be replaced by  trans_less_add1
   303   le_imp_add_le      should be replaced by  trans_le_add1
   304 
   305 * HOL: unary minus is now overloaded (new type constraints may be
   306 required);
   307 
   308 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
   309 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
   310 now taken as an integer constant.
   311 
   312 * Pure: ML function 'theory_of' renamed to 'theory';
   313 
   314 
   315 *** Proof tools ***
   316 
   317 * Simplifier:
   318   1. Asm_full_simp_tac is now more aggressive.
   319      1. It will sometimes reorient premises if that increases their power to
   320         simplify.
   321      2. It does no longer proceed strictly from left to right but may also
   322         rotate premises to achieve further simplification.
   323      For compatibility reasons there is now Asm_lr_simp_tac which is like the
   324      old Asm_full_simp_tac in that it does not rotate premises.
   325   2. The simplifier now knows a little bit about nat-arithmetic.
   326 
   327 * Classical reasoner: wrapper mechanism for the classical reasoner now
   328 allows for selected deletion of wrappers, by introduction of names for
   329 wrapper functionals.  This implies that addbefore, addSbefore,
   330 addaltern, and addSaltern now take a pair (name, tactic) as argument,
   331 and that adding two tactics with the same name overwrites the first
   332 one (emitting a warning).
   333   type wrapper = (int -> tactic) -> (int -> tactic)
   334   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
   335   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
   336   delWrapper, delSWrapper: claset *  string            -> claset
   337   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
   338 
   339 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
   340 semantics; addbefore now affects only the unsafe part of step_tac
   341 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
   342 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
   343 by Force_tac;
   344 
   345 * Classical reasoner: setwrapper to setWrapper and compwrapper to
   346 compWrapper; added safe wrapper (and access functions for it);
   347 
   348 * HOL/split_all_tac is now much faster and fails if there is nothing
   349 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
   350 and the names of the automatically generated variables have changed.
   351 split_all_tac has moved within claset() from unsafe wrappers to safe
   352 wrappers, which means that !!-bound variables are split much more
   353 aggressively, and safe_tac and clarify_tac now split such variables.
   354 If this splitting is not appropriate, use delSWrapper "split_all_tac".
   355 Note: the same holds for record_split_tac, which does the job of
   356 split_all_tac for record fields.
   357 
   358 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
   359 permanently to the default simpset using Addsplits just like
   360 Addsimps. They can be removed via Delsplits just like
   361 Delsimps. Lower-case versions are also available.
   362 
   363 * HOL/Simplifier: The rule split_if is now part of the default
   364 simpset. This means that the simplifier will eliminate all occurrences
   365 of if-then-else in the conclusion of a goal. To prevent this, you can
   366 either remove split_if completely from the default simpset by
   367 `Delsplits [split_if]' or remove it in a specific call of the
   368 simplifier using `... delsplits [split_if]'.  You can also add/delete
   369 other case splitting rules to/from the default simpset: every datatype
   370 generates suitable rules `split_t_case' and `split_t_case_asm' (where
   371 t is the name of the datatype).
   372 
   373 * Classical reasoner / Simplifier combination: new force_tac (and
   374 derivatives Force_tac, force) combines rewriting and classical
   375 reasoning (and whatever other tools) similarly to auto_tac, but is
   376 aimed to solve the given subgoal completely.
   377 
   378 
   379 *** General ***
   380 
   381 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
   382 and `goalw': the theory is no longer needed as an explicit argument -
   383 the current theory context is used; assumptions are no longer returned
   384 at the ML-level unless one of them starts with ==> or !!; it is
   385 recommended to convert to these new commands using isatool fixgoal
   386 (backup your sources first!);
   387 
   388 * new top-level commands 'thm' and 'thms' for retrieving theorems from
   389 the current theory context, and 'theory' to lookup stored theories;
   390 
   391 * new theory section 'locale' for declaring constants, assumptions and
   392 definitions that have local scope;
   393 
   394 * new theory section 'nonterminals' for purely syntactic types;
   395 
   396 * new theory section 'setup' for generic ML setup functions
   397 (e.g. package initialization);
   398 
   399 * the distribution now includes Isabelle icons: see
   400 lib/logo/isabelle-{small,tiny}.xpm;
   401 
   402 * isatool install - install binaries with absolute references to
   403 ISABELLE_HOME/bin;
   404 
   405 * isatool logo -- create instances of the Isabelle logo (as EPS);
   406 
   407 * print mode 'emacs' reserved for Isamode;
   408 
   409 * support multiple print (ast) translations per constant name;
   410 
   411 * theorems involving oracles are now printed with a suffixed [!];
   412 
   413 
   414 *** HOL ***
   415 
   416 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
   417 
   418 * HOL/inductive package reorganized and improved: now supports mutual
   419 definitions such as
   420 
   421   inductive EVEN ODD
   422     intrs
   423       null "0 : EVEN"
   424       oddI "n : EVEN ==> Suc n : ODD"
   425       evenI "n : ODD ==> Suc n : EVEN"
   426 
   427 new theorem list "elims" contains an elimination rule for each of the
   428 recursive sets; inductive definitions now handle disjunctive premises
   429 correctly (also ZF);
   430 
   431 INCOMPATIBILITIES: requires Inductive as an ancestor; component
   432 "mutual_induct" no longer exists - the induction rule is always
   433 contained in "induct";
   434 
   435 
   436 * HOL/datatype package re-implemented and greatly improved: now
   437 supports mutually recursive datatypes such as
   438 
   439   datatype
   440     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
   441             | SUM ('a aexp) ('a aexp)
   442             | DIFF ('a aexp) ('a aexp)
   443             | NUM 'a
   444   and
   445     'a bexp = LESS ('a aexp) ('a aexp)
   446             | AND ('a bexp) ('a bexp)
   447             | OR ('a bexp) ('a bexp)
   448 
   449 as well as indirectly recursive datatypes such as
   450 
   451   datatype
   452     ('a, 'b) term = Var 'a
   453                   | App 'b ((('a, 'b) term) list)
   454 
   455 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
   456 induction on mutually / indirectly recursive datatypes.
   457 
   458 Primrec equations are now stored in theory and can be accessed via
   459 <function_name>.simps.
   460 
   461 INCOMPATIBILITIES:
   462 
   463   - Theories using datatypes must now have theory Datatype as an
   464     ancestor.
   465   - The specific <typename>.induct_tac no longer exists - use the
   466     generic induct_tac instead.
   467   - natE has been renamed to nat.exhaust - use exhaust_tac
   468     instead of res_inst_tac ... natE. Note that the variable
   469     names in nat.exhaust differ from the names in natE, this
   470     may cause some "fragile" proofs to fail.
   471   - The theorems split_<typename>_case and split_<typename>_case_asm
   472     have been renamed to <typename>.split and <typename>.split_asm.
   473   - Since default sorts of type variables are now handled correctly,
   474     some datatype definitions may have to be annotated with explicit
   475     sort constraints.
   476   - Primrec definitions no longer require function name and type
   477     of recursive argument.
   478 
   479 Consider using isatool fixdatatype to adapt your theories and proof
   480 scripts to the new package (backup your sources first!).
   481 
   482 
   483 * HOL/record package: considerably improved implementation; now
   484 includes concrete syntax for record types, terms, updates; theorems
   485 for surjective pairing and splitting !!-bound record variables; proof
   486 support is as follows:
   487 
   488   1) standard conversions (selectors or updates applied to record
   489 constructor terms) are part of the standard simpset;
   490 
   491   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
   492 made part of standard simpset and claset via addIffs;
   493 
   494   3) a tactic for record field splitting (record_split_tac) is part of
   495 the standard claset (addSWrapper);
   496 
   497 To get a better idea about these rules you may retrieve them via
   498 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
   499 the name of your record type.
   500 
   501 The split tactic 3) conceptually simplifies by the following rule:
   502 
   503   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
   504 
   505 Thus any record variable that is bound by meta-all will automatically
   506 blow up into some record constructor term, consequently the
   507 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
   508 solve record problems automatically.
   509 
   510 
   511 * reorganized the main HOL image: HOL/Integ and String loaded by
   512 default; theory Main includes everything;
   513 
   514 * automatic simplification of integer sums and comparisons, using cancellation;
   515 
   516 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
   517 
   518 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
   519 
   520 * many new identities for unions, intersections, set difference, etc.;
   521 
   522 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
   523 called split_if, split_split, split_sum_case and split_nat_case (to go
   524 with add/delsplits);
   525 
   526 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
   527 (?x::unit) = (); this is made part of the default simpset, which COULD
   528 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
   529 'Delsimprocs [unit_eq_proc];' as last resort); also note that
   530 unit_abs_eta_conv is added in order to counter the effect of
   531 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
   532 %u.f();
   533 
   534 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
   535 makes more sense);
   536 
   537 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   538   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   539   disjointness reasoning but breaking a few old proofs.
   540 
   541 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
   542 to 'converse' from 'inverse' (for compatibility with ZF and some
   543 literature);
   544 
   545 * HOL/recdef can now declare non-recursive functions, with {} supplied as
   546 the well-founded relation;
   547 
   548 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
   549     Compl A.  The "Compl" syntax remains available as input syntax for this
   550     release ONLY.
   551 
   552 * HOL/Update: new theory of function updates:
   553     f(a:=b) == %x. if x=a then b else f x
   554 may also be iterated as in f(a:=b,c:=d,...);
   555 
   556 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
   557 
   558 * HOL/List:
   559   - new function list_update written xs[i:=v] that updates the i-th
   560     list position. May also be iterated as in xs[i:=a,j:=b,...].
   561   - new function `upt' written [i..j(] which generates the list
   562     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
   563     bound write [i..j], which is a shorthand for [i..j+1(].
   564   - new lexicographic orderings and corresponding wellfoundedness theorems.
   565 
   566 * HOL/Arith:
   567   - removed 'pred' (predecessor) function;
   568   - generalized some theorems about n-1;
   569   - many new laws about "div" and "mod";
   570   - new laws about greatest common divisors (see theory ex/Primes);
   571 
   572 * HOL/Relation: renamed the relational operator r^-1 "converse"
   573 instead of "inverse";
   574 
   575 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
   576   of the multiset ordering;
   577 
   578 * directory HOL/Real: a construction of the reals using Dedekind cuts
   579   (not included by default);
   580 
   581 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
   582 
   583 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
   584   programs, i.e. different program variables may have different types.
   585 
   586 * calling (stac rew i) now fails if "rew" has no effect on the goal
   587   [previously, this check worked only if the rewrite rule was unconditional]
   588   Now rew can involve either definitions or equalities (either == or =).
   589 
   590 
   591 *** ZF ***
   592 
   593 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
   594   only the theorems proved on ZF.ML;
   595 
   596 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   597   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   598   disjointness reasoning but breaking a few old proofs.
   599 
   600 * ZF/Update: new theory of function updates
   601     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
   602   may also be iterated as in f(a:=b,c:=d,...);
   603 
   604 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
   605 
   606 * calling (stac rew i) now fails if "rew" has no effect on the goal
   607   [previously, this check worked only if the rewrite rule was unconditional]
   608   Now rew can involve either definitions or equalities (either == or =).
   609 
   610 * case_tac provided for compatibility with HOL
   611     (like the old excluded_middle_tac, but with subgoals swapped)
   612 
   613 
   614 *** Internal programming interfaces ***
   615 
   616 * Pure: several new basic modules made available for general use, see
   617 also src/Pure/README;
   618 
   619 * improved the theory data mechanism to support encapsulation (data
   620 kind name replaced by private Object.kind, acting as authorization
   621 key); new type-safe user interface via functor TheoryDataFun; generic
   622 print_data function becomes basically useless;
   623 
   624 * removed global_names compatibility flag -- all theory declarations
   625 are qualified by default;
   626 
   627 * module Pure/Syntax now offers quote / antiquote translation
   628 functions (useful for Hoare logic etc. with implicit dependencies);
   629 see HOL/ex/Antiquote for an example use;
   630 
   631 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
   632 cterm -> thm;
   633 
   634 * new tactical CHANGED_GOAL for checking that a tactic modifies a
   635 subgoal;
   636 
   637 * Display.print_goals function moved to Locale.print_goals;
   638 
   639 * standard print function for goals supports current_goals_markers
   640 variable for marking begin of proof, end of proof, start of goal; the
   641 default is ("", "", ""); setting current_goals_markers := ("<proof>",
   642 "</proof>", "<goal>") causes SGML like tagged proof state printing,
   643 for example;
   644 
   645 
   646 
   647 New in Isabelle98 (January 1998)
   648 --------------------------------
   649 
   650 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   651 
   652 * changed lexical syntax of terms / types: dots made part of long
   653 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
   654 
   655 * simpset (and claset) reference variable replaced by functions
   656 simpset / simpset_ref;
   657 
   658 * no longer supports theory aliases (via merge) and non-trivial
   659 implicit merge of thms' signatures;
   660 
   661 * most internal names of constants changed due to qualified names;
   662 
   663 * changed Pure/Sequence interface (see Pure/seq.ML);
   664 
   665 
   666 *** General Changes ***
   667 
   668 * hierachically structured name spaces (for consts, types, axms, thms
   669 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
   670 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
   671 isatool fixdots ensures space after dots (e.g. "%x. x"); set
   672 long_names for fully qualified output names; NOTE: ML programs
   673 (special tactics, packages etc.) referring to internal names may have
   674 to be adapted to cope with fully qualified names; in case of severe
   675 backward campatibility problems try setting 'global_names' at compile
   676 time to have enrything declared within a flat name space; one may also
   677 fine tune name declarations in theories via the 'global' and 'local'
   678 section;
   679 
   680 * reimplemented the implicit simpset and claset using the new anytype
   681 data filed in signatures; references simpset:simpset ref etc. are
   682 replaced by functions simpset:unit->simpset and
   683 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
   684 to patch your ML files accordingly;
   685 
   686 * HTML output now includes theory graph data for display with Java
   687 applet or isatool browser; data generated automatically via isatool
   688 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
   689 
   690 * defs may now be conditional; improved rewrite_goals_tac to handle
   691 conditional equations;
   692 
   693 * defs now admits additional type arguments, using TYPE('a) syntax;
   694 
   695 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
   696 creates a new theory node; implicit merge of thms' signatures is
   697 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
   698 transfer:theory->thm->thm in (rare) cases;
   699 
   700 * improved handling of draft signatures / theories; draft thms (and
   701 ctyps, cterms) are automatically promoted to real ones;
   702 
   703 * slightly changed interfaces for oracles: admit many per theory, named
   704 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
   705 
   706 * print_goals: optional output of const types (set show_consts and
   707 show_types);
   708 
   709 * improved output of warnings (###) and errors (***);
   710 
   711 * subgoal_tac displays a warning if the new subgoal has type variables;
   712 
   713 * removed old README and Makefiles;
   714 
   715 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
   716 
   717 * removed obsolete init_pps and init_database;
   718 
   719 * deleted the obsolete tactical STATE, which was declared by
   720     fun STATE tacfun st = tacfun st st;
   721 
   722 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
   723 (which abbreviates $HOME);
   724 
   725 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
   726 use isatool fixseq to adapt your ML programs (this works for fully
   727 qualified references to the Sequence structure only!);
   728 
   729 * use_thy no longer requires writable current directory; it always
   730 reloads .ML *and* .thy file, if either one is out of date;
   731 
   732 
   733 *** Classical Reasoner ***
   734 
   735 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
   736 tactics that use classical reasoning to simplify a subgoal without
   737 splitting it into several subgoals;
   738 
   739 * Safe_tac: like safe_tac but uses the default claset;
   740 
   741 
   742 *** Simplifier ***
   743 
   744 * added simplification meta rules:
   745     (asm_)(full_)simplify: simpset -> thm -> thm;
   746 
   747 * simplifier.ML no longer part of Pure -- has to be loaded by object
   748 logics (again);
   749 
   750 * added prems argument to simplification procedures;
   751 
   752 * HOL, FOL, ZF: added infix function `addsplits':
   753   instead of `<simpset> setloop (split_tac <thms>)'
   754   you can simply write `<simpset> addsplits <thms>'
   755 
   756 
   757 *** Syntax ***
   758 
   759 * TYPE('a) syntax for type reflection terms;
   760 
   761 * no longer handles consts with name "" -- declare as 'syntax' instead;
   762 
   763 * pretty printer: changed order of mixfix annotation preference (again!);
   764 
   765 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
   766 
   767 
   768 *** HOL ***
   769 
   770 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
   771   with `addloop' of the simplifier to faciliate case splitting in premises.
   772 
   773 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
   774 
   775 * HOL/Auth: new protocol proofs including some for the Internet
   776   protocol TLS;
   777 
   778 * HOL/Map: new theory of `maps' a la VDM;
   779 
   780 * HOL/simplifier: simplification procedures nat_cancel_sums for
   781 cancelling out common nat summands from =, <, <= (in)equalities, or
   782 differences; simplification procedures nat_cancel_factor for
   783 cancelling common factor from =, <, <= (in)equalities over natural
   784 sums; nat_cancel contains both kinds of procedures, it is installed by
   785 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
   786 
   787 * HOL/simplifier: terms of the form
   788   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
   789   are rewritten to
   790   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
   791   and those of the form
   792   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
   793   are rewritten to
   794   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
   795 
   796 * HOL/datatype
   797   Each datatype `t' now comes with a theorem `split_t_case' of the form
   798 
   799   P(t_case f1 ... fn x) =
   800      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
   801         ...
   802        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
   803      )
   804 
   805   and a theorem `split_t_case_asm' of the form
   806 
   807   P(t_case f1 ... fn x) =
   808     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
   809         ...
   810        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
   811      )
   812   which can be added to a simpset via `addsplits'. The existing theorems
   813   expand_list_case and expand_option_case have been renamed to
   814   split_list_case and split_option_case.
   815 
   816 * HOL/Arithmetic:
   817   - `pred n' is automatically converted to `n-1'.
   818     Users are strongly encouraged not to use `pred' any longer,
   819     because it will disappear altogether at some point.
   820   - Users are strongly encouraged to write "0 < n" rather than
   821     "n ~= 0". Theorems and proof tools have been modified towards this
   822     `standard'.
   823 
   824 * HOL/Lists:
   825   the function "set_of_list" has been renamed "set" (and its theorems too);
   826   the function "nth" now takes its arguments in the reverse order and
   827   has acquired the infix notation "!" as in "xs!n".
   828 
   829 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
   830 
   831 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
   832   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
   833 
   834 * HOL/record: extensible records with schematic structural subtyping
   835 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
   836 still lacks various theorems and concrete record syntax;
   837 
   838 
   839 *** HOLCF ***
   840 
   841 * removed "axioms" and "generated by" sections;
   842 
   843 * replaced "ops" section by extended "consts" section, which is capable of
   844   handling the continuous function space "->" directly;
   845 
   846 * domain package:
   847   . proves theorems immediately and stores them in the theory,
   848   . creates hierachical name space,
   849   . now uses normal mixfix annotations (instead of cinfix...),
   850   . minor changes to some names and values (for consistency),
   851   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
   852   . separator between mutual domain defs: changed "," to "and",
   853   . improved handling of sort constraints;  now they have to
   854     appear on the left-hand side of the equations only;
   855 
   856 * fixed LAM <x,y,zs>.b syntax;
   857 
   858 * added extended adm_tac to simplifier in HOLCF -- can now discharge
   859 adm (%x. P (t x)), where P is chainfinite and t continuous;
   860 
   861 
   862 *** FOL and ZF ***
   863 
   864 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
   865   with `addloop' of the simplifier to faciliate case splitting in premises.
   866 
   867 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
   868 in HOL, they strip ALL and --> from proved theorems;
   869 
   870 
   871 
   872 New in Isabelle94-8 (May 1997)
   873 ------------------------------
   874 
   875 *** General Changes ***
   876 
   877 * new utilities to build / run / maintain Isabelle etc. (in parts
   878 still somewhat experimental); old Makefiles etc. still functional;
   879 
   880 * new 'Isabelle System Manual';
   881 
   882 * INSTALL text, together with ./configure and ./build scripts;
   883 
   884 * reimplemented type inference for greater efficiency, better error
   885 messages and clean internal interface;
   886 
   887 * prlim command for dealing with lots of subgoals (an easier way of
   888 setting goals_limit);
   889 
   890 
   891 *** Syntax ***
   892 
   893 * supports alternative (named) syntax tables (parser and pretty
   894 printer); internal interface is provided by add_modesyntax(_i);
   895 
   896 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
   897 be used in conjunction with the Isabelle symbol font; uses the
   898 "symbols" syntax table;
   899 
   900 * added token_translation interface (may translate name tokens in
   901 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
   902 the current print_mode); IMPORTANT: user print translation functions
   903 are responsible for marking newly introduced bounds
   904 (Syntax.mark_boundT);
   905 
   906 * token translations for modes "xterm" and "xterm_color" that display
   907 names in bold, underline etc. or colors (which requires a color
   908 version of xterm);
   909 
   910 * infixes may now be declared with names independent of their syntax;
   911 
   912 * added typed_print_translation (like print_translation, but may
   913 access type of constant);
   914 
   915 
   916 *** Classical Reasoner ***
   917 
   918 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
   919 some limitations.  Blast_tac...
   920   + ignores addss, addbefore, addafter; this restriction is intrinsic
   921   + ignores elimination rules that don't have the correct format
   922         (the conclusion MUST be a formula variable)
   923   + ignores types, which can make HOL proofs fail
   924   + rules must not require higher-order unification, e.g. apply_type in ZF
   925     [message "Function Var's argument not a bound variable" relates to this]
   926   + its proof strategy is more general but can actually be slower
   927 
   928 * substitution with equality assumptions no longer permutes other
   929 assumptions;
   930 
   931 * minor changes in semantics of addafter (now called addaltern); renamed
   932 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
   933 (and access functions for it);
   934 
   935 * improved combination of classical reasoner and simplifier:
   936   + functions for handling clasimpsets
   937   + improvement of addss: now the simplifier is called _after_ the
   938     safe steps.
   939   + safe variant of addss called addSss: uses safe simplifications
   940     _during_ the safe steps. It is more complete as it allows multiple
   941     instantiations of unknowns (e.g. with slow_tac).
   942 
   943 *** Simplifier ***
   944 
   945 * added interface for simplification procedures (functions that
   946 produce *proven* rewrite rules on the fly, depending on current
   947 redex);
   948 
   949 * ordering on terms as parameter (used for ordered rewriting);
   950 
   951 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
   952 
   953 * the solver is now split into a safe and an unsafe part.
   954 This should be invisible for the normal user, except that the
   955 functions setsolver and addsolver have been renamed to setSolver and
   956 addSolver; added safe_asm_full_simp_tac;
   957 
   958 
   959 *** HOL ***
   960 
   961 * a generic induction tactic `induct_tac' which works for all datatypes and
   962 also for type `nat';
   963 
   964 * a generic case distinction tactic `exhaust_tac' which works for all
   965 datatypes and also for type `nat';
   966 
   967 * each datatype comes with a function `size';
   968 
   969 * patterns in case expressions allow tuple patterns as arguments to
   970 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
   971 
   972 * primrec now also works with type nat;
   973 
   974 * recdef: a new declaration form, allows general recursive functions to be
   975 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
   976 
   977 * the constant for negation has been renamed from "not" to "Not" to
   978 harmonize with FOL, ZF, LK, etc.;
   979 
   980 * HOL/ex/LFilter theory of a corecursive "filter" functional for
   981 infinite lists;
   982 
   983 * HOL/Modelcheck demonstrates invocation of model checker oracle;
   984 
   985 * HOL/ex/Ring.thy declares cring_simp, which solves equational
   986 problems in commutative rings, using axiomatic type classes for + and *;
   987 
   988 * more examples in HOL/MiniML and HOL/Auth;
   989 
   990 * more default rewrite rules for quantifiers, union/intersection;
   991 
   992 * a new constant `arbitrary == @x.False';
   993 
   994 * HOLCF/IOA replaces old HOL/IOA;
   995 
   996 * HOLCF changes: derived all rules and arities
   997   + axiomatic type classes instead of classes
   998   + typedef instead of faking type definitions
   999   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  1000   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  1001   + eliminated the types void, one, tr
  1002   + use unit lift and bool lift (with translations) instead of one and tr
  1003   + eliminated blift from Lift3.thy (use Def instead of blift)
  1004   all eliminated rules are derived as theorems --> no visible changes ;
  1005 
  1006 
  1007 *** ZF ***
  1008 
  1009 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  1010 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  1011 as ZF_cs addSIs [equalityI];
  1012 
  1013 
  1014 
  1015 New in Isabelle94-7 (November 96)
  1016 ---------------------------------
  1017 
  1018 * allowing negative levels (as offsets) in prlev and choplev;
  1019 
  1020 * super-linear speedup for large simplifications;
  1021 
  1022 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  1023 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  1024 FAIL); can suppress it using the command Delsimps (ex_simps @
  1025 all_simps); De Morgan laws are also now included, by default;
  1026 
  1027 * improved printing of ==>  :  ~:
  1028 
  1029 * new object-logic "Sequents" adds linear logic, while replacing LK
  1030 and Modal (thanks to Sara Kalvala);
  1031 
  1032 * HOL/Auth: correctness proofs for authentication protocols;
  1033 
  1034 * HOL: new auto_tac combines rewriting and classical reasoning (many
  1035 examples on HOL/Auth);
  1036 
  1037 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  1038 the rewriter and classical reasoner simultaneously;
  1039 
  1040 * function uresult no longer returns theorems in "standard" format;
  1041 regain previous version by: val uresult = standard o uresult;
  1042 
  1043 
  1044 
  1045 New in Isabelle94-6
  1046 -------------------
  1047 
  1048 * oracles -- these establish an interface between Isabelle and trusted
  1049 external reasoners, which may deliver results as theorems;
  1050 
  1051 * proof objects (in particular record all uses of oracles);
  1052 
  1053 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  1054 
  1055 * "constdefs" section in theory files;
  1056 
  1057 * "primrec" section (HOL) no longer requires names;
  1058 
  1059 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  1060 
  1061 
  1062 
  1063 New in Isabelle94-5
  1064 -------------------
  1065 
  1066 * reduced space requirements;
  1067 
  1068 * automatic HTML generation from theories;
  1069 
  1070 * theory files no longer require "..." (quotes) around most types;
  1071 
  1072 * new examples, including two proofs of the Church-Rosser theorem;
  1073 
  1074 * non-curried (1994) version of HOL is no longer distributed;
  1075 
  1076 
  1077 
  1078 New in Isabelle94-4
  1079 -------------------
  1080 
  1081 * greatly reduced space requirements;
  1082 
  1083 * theory files (.thy) no longer require \...\ escapes at line breaks;
  1084 
  1085 * searchable theorem database (see the section "Retrieving theorems" on
  1086 page 8 of the Reference Manual);
  1087 
  1088 * new examples, including Grabczewski's monumental case study of the
  1089 Axiom of Choice;
  1090 
  1091 * The previous version of HOL renamed to Old_HOL;
  1092 
  1093 * The new version of HOL (previously called CHOL) uses a curried syntax
  1094 for functions.  Application looks like f a b instead of f(a,b);
  1095 
  1096 * Mutually recursive inductive definitions finally work in HOL;
  1097 
  1098 * In ZF, pattern-matching on tuples is now available in all abstractions and
  1099 translates to the operator "split";
  1100 
  1101 
  1102 
  1103 New in Isabelle94-3
  1104 -------------------
  1105 
  1106 * new infix operator, addss, allowing the classical reasoner to
  1107 perform simplification at each step of its search.  Example:
  1108         fast_tac (cs addss ss)
  1109 
  1110 * a new logic, CHOL, the same as HOL, but with a curried syntax
  1111 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  1112 look like (a,b) instead of <a,b>;
  1113 
  1114 * PLEASE NOTE: CHOL will eventually replace HOL!
  1115 
  1116 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  1117 It translates to the operator "split".  A new theory of integers is available;
  1118 
  1119 * In ZF, integer numerals now denote two's-complement binary integers.
  1120 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  1121 
  1122 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  1123 of the Axiom of Choice;
  1124 
  1125 
  1126 
  1127 New in Isabelle94-2
  1128 -------------------
  1129 
  1130 * Significantly faster resolution;
  1131 
  1132 * the different sections in a .thy file can now be mixed and repeated
  1133 freely;
  1134 
  1135 * Database of theorems for FOL, HOL and ZF.  New
  1136 commands including qed, qed_goal and bind_thm store theorems in the database.
  1137 
  1138 * Simple database queries: return a named theorem (get_thm) or all theorems of
  1139 a given theory (thms_of), or find out what theory a theorem was proved in
  1140 (theory_of_thm);
  1141 
  1142 * Bugs fixed in the inductive definition and datatype packages;
  1143 
  1144 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  1145 and HOL_dup_cs obsolete;
  1146 
  1147 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  1148 have been removed;
  1149 
  1150 * Simpler definition of function space in ZF;
  1151 
  1152 * new results about cardinal and ordinal arithmetic in ZF;
  1153 
  1154 * 'subtype' facility in HOL for introducing new types as subsets of existing
  1155 types;
  1156 
  1157 
  1158 $Id$