NEWS
author nipkow
Fri Mar 10 17:14:56 2000 +0100 (2000-03-10)
changeset 8412 65f9089f6f71
parent 8392 5bf82327aa36
child 8425 f03c667cf702
permissions -rw-r--r--
cases_tac
     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: "case_tac" is now called "cases_tac" (see below)
    11 
    12 * HOL: the constant for f``x is now "image" rather than "op ``".
    13 
    14 
    15 *** Isabelle document preparation ***
    16 
    17 * isatool mkdir provides easy setup of Isabelle session directories,
    18 including proper documents;
    19 
    20 * generated LaTeX sources are now deleted after successful run
    21 (isatool document -c); may retain a copy somewhere else via -D option
    22 of isatool usedir;
    23 
    24 * old-style theories now produce (crude) LaTeX sources as well;
    25 
    26 
    27 *** Isar ***
    28 
    29 * names of theorems etc. may be natural numbers as well;
    30 
    31 * intro/elim/dest attributes: changed ! / !! flags to ? / ??;
    32 
    33 * Pure now provides its own version of intro/elim/dest attributes;
    34 useful for building new logics, but beware of confusion with the
    35 Provers/classical ones!
    36 
    37 * new 'obtain' language element supports generalized existence proofs;
    38 
    39 * HOL: removed "case_split" thm binding, should use "cases" proof
    40 method anyway;
    41 
    42 * tuned syntax of "induct" method;
    43 
    44 * new "cases" method for propositions, inductive sets and types;
    45 
    46 
    47 *** HOL ***
    48 
    49 * Algebra: new theory of rings and univariate polynomials, by Clemens
    50 Ballarin;
    51 
    52 * HOL/record: fixed select-update simplification procedure to handle
    53 extended records as well; admit "r" as field name;
    54 
    55 * HOL/ex: new theory Factorization proving the Fundamental Theorem of
    56 Arithmetic, by Thomas M Rasmussen;
    57 
    58 * There is a new tactic "cases_tac" for case distinctions; it subsumes the
    59 old "case_tac" (no longer available) and "exhaust_tac" (which should no
    60 longer be used).
    61 
    62 *** General ***
    63 
    64 * compression of ML heaps images may now be controlled via -c option
    65 of isabelle and isatool usedir;
    66 
    67 
    68 
    69 New in Isabelle99 (October 1999)
    70 --------------------------------
    71 
    72 *** Overview of INCOMPATIBILITIES (see below for more details) ***
    73 
    74 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
    75 are no longer simplified.  (This allows the simplifier to unfold recursive
    76 functional programs.)  To restore the old behaviour, declare
    77 
    78     Delcongs [if_weak_cong];
    79 
    80 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
    81 complement;
    82 
    83 * HOL: the predicate "inj" is now defined by translation to "inj_on";
    84 
    85 * HOL/datatype: mutual_induct_tac no longer exists --
    86   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
    87 
    88 * HOL/typedef: fixed type inference for representing set; type
    89 arguments now have to occur explicitly on the rhs as type constraints;
    90 
    91 * ZF: The con_defs part of an inductive definition may no longer refer
    92 to constants declared in the same theory;
    93 
    94 * HOL, ZF: the function mk_cases, generated by the inductive
    95 definition package, has lost an argument.  To simplify its result, it
    96 uses the default simpset instead of a supplied list of theorems.
    97 
    98 * HOL/List: the constructors of type list are now Nil and Cons;
    99 
   100 * Simplifier: the type of the infix ML functions
   101 	setSSolver addSSolver setSolver addSolver
   102 is now  simpset * solver -> simpset  where `solver' is a new abstract type
   103 for packaging solvers. A solver is created via
   104 	mk_solver: string -> (thm list -> int -> tactic) -> solver
   105 where the string argument is only a comment.
   106 
   107 
   108 *** Proof tools ***
   109 
   110 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
   111 decision procedure for linear arithmetic. Currently it is used for
   112 types `nat', `int', and `real' in HOL (see below); it can, should and
   113 will be instantiated for other types and logics as well.
   114 
   115 * The simplifier now accepts rewrite rules with flexible heads, eg
   116      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
   117   They are applied like any rule with a non-pattern lhs, i.e. by first-order
   118   matching.
   119 
   120 
   121 *** General ***
   122 
   123 * New Isabelle/Isar subsystem provides an alternative to traditional
   124 tactical theorem proving; together with the ProofGeneral/isar user
   125 interface it offers an interactive environment for developing human
   126 readable proof documents (Isar == Intelligible semi-automated
   127 reasoning); for further information see isatool doc isar-ref,
   128 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
   129 
   130 * improved presentation of theories: better HTML markup (including
   131 colors), graph views in several sizes; isatool usedir now provides a
   132 proper interface for user theories (via -P option); actual document
   133 preparation based on (PDF)LaTeX is available as well (for new-style
   134 theories only); see isatool doc system for more information;
   135 
   136 * native support for Proof General, both for classic Isabelle and
   137 Isabelle/Isar;
   138 
   139 * ML function thm_deps visualizes dependencies of theorems and lemmas,
   140 using the graph browser tool;
   141 
   142 * Isabelle manuals now also available as PDF;
   143 
   144 * theory loader rewritten from scratch (may not be fully
   145 bug-compatible); old loadpath variable has been replaced by show_path,
   146 add_path, del_path, reset_path functions; new operations such as
   147 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
   148 isatool doc ref);
   149 
   150 * improved isatool install: option -k creates KDE application icon,
   151 option -p DIR installs standalone binaries;
   152 
   153 * added ML_PLATFORM setting (useful for cross-platform installations);
   154 more robust handling of platform specific ML images for SML/NJ;
   155 
   156 * the settings environment is now statically scoped, i.e. it is never
   157 created again in sub-processes invoked from isabelle, isatool, or
   158 Isabelle;
   159 
   160 * path element specification '~~' refers to '$ISABELLE_HOME';
   161 
   162 * in locales, the "assumes" and "defines" parts may be omitted if
   163 empty;
   164 
   165 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
   166 long arrows);
   167 
   168 * new print_mode "HTML";
   169 
   170 * new flag show_tags controls display of tags of theorems (which are
   171 basically just comments that may be attached by some tools);
   172 
   173 * Isamode 2.6 requires patch to accomodate change of Isabelle font
   174 mode and goal output format:
   175 
   176 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
   177 244c244
   178 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
   179 ---
   180 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
   181 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
   182 181c181
   183 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
   184 ---
   185 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
   186 
   187 * function bind_thms stores lists of theorems (cf. bind_thm);
   188 
   189 * new shorthand tactics ftac, eatac, datac, fatac;
   190 
   191 * qed (and friends) now accept "" as result name; in that case the
   192 theorem is not stored, but proper checks and presentation of the
   193 result still apply;
   194 
   195 * theorem database now also indexes constants "Trueprop", "all",
   196 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
   197 
   198 
   199 *** HOL ***
   200 
   201 ** HOL arithmetic **
   202 
   203 * There are now decision procedures for linear arithmetic over nat and
   204 int:
   205 
   206 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
   207 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
   208 are treated as atomic; subformulae not involving type `nat' or `int'
   209 are ignored; quantified subformulae are ignored unless they are
   210 positive universal or negative existential. The tactic has to be
   211 invoked by hand and can be a little bit slow. In particular, the
   212 running time is exponential in the number of occurrences of `min' and
   213 `max', and `-' on `nat'.
   214 
   215 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
   216 (negated) (in)equalities among the premises and the conclusion into
   217 account (i.e. no compound formulae) and does not know about `min' and
   218 `max', and `-' on `nat'. It is fast and is used automatically by the
   219 simplifier.
   220 
   221 NB: At the moment, these decision procedures do not cope with mixed
   222 nat/int formulae where the two parts interact, such as `m < n ==>
   223 int(m) < int(n)'.
   224 
   225 * HOL/Numeral provides a generic theory of numerals (encoded
   226 efficiently as bit strings); setup for types nat/int/real is in place;
   227 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
   228 int, existing theories and proof scripts may require a few additional
   229 type constraints;
   230 
   231 * integer division and remainder can now be performed on constant
   232 arguments;
   233 
   234 * many properties of integer multiplication, division and remainder
   235 are now available;
   236 
   237 * An interface to the Stanford Validity Checker (SVC) is available through the
   238 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
   239 are proved automatically.  SVC must be installed separately, and its results
   240 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
   241 invocation of the underlying oracle).  For SVC see
   242   http://verify.stanford.edu/SVC
   243 
   244 * IsaMakefile: the HOL-Real target now builds an actual image;
   245 
   246 
   247 ** HOL misc **
   248 
   249 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
   250 (in Isabelle/Isar) -- by Gertrud Bauer;
   251 
   252 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
   253 analysis for assembly languages with subtypes;
   254 
   255 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
   256 -- avoids syntactic ambiguities and treats state, transition, and
   257 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
   258 changed syntax and (many) tactics;
   259 
   260 * HOL/inductive: Now also handles more general introduction rules such
   261   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
   262   theorems are now maintained within the theory (maintained via the
   263   "mono" attribute);
   264 
   265 * HOL/datatype: Now also handles arbitrarily branching datatypes
   266   (using function types) such as
   267 
   268   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
   269 
   270 * HOL/record: record_simproc (part of the default simpset) takes care
   271 of selectors applied to updated records; record_split_tac is no longer
   272 part of the default claset; update_defs may now be removed from the
   273 simpset in many cases; COMPATIBILITY: old behavior achieved by
   274 
   275   claset_ref () := claset() addSWrapper record_split_wrapper;
   276   Delsimprocs [record_simproc]
   277 
   278 * HOL/typedef: fixed type inference for representing set; type
   279 arguments now have to occur explicitly on the rhs as type constraints;
   280 
   281 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
   282 names rather than an ML expression;
   283 
   284 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
   285 supplied later.  Program schemes can be defined, such as
   286     "While B C s = (if B s then While B C (C s) else s)"
   287 where the well-founded relation can be chosen after B and C have been given.
   288 
   289 * HOL/List: the constructors of type list are now Nil and Cons;
   290 INCOMPATIBILITY: while [] and infix # syntax is still there, of
   291 course, ML tools referring to List.list.op # etc. have to be adapted;
   292 
   293 * HOL_quantifiers flag superseded by "HOL" print mode, which is
   294 disabled by default; run isabelle with option -m HOL to get back to
   295 the original Gordon/HOL-style output;
   296 
   297 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
   298 ALL x<=y. P, EX x<y. P, EX x<=y. P;
   299 
   300 * HOL basic syntax simplified (more orthogonal): all variants of
   301 All/Ex now support plain / symbolic / HOL notation; plain syntax for
   302 Eps operator is provided as well: "SOME x. P[x]";
   303 
   304 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
   305 
   306 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
   307 thus available for user theories;
   308 
   309 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
   310 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
   311 time;
   312 
   313 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
   314 several times and then mp;
   315 
   316 
   317 *** LK ***
   318 
   319 * the notation <<...>> is now available as a notation for sequences of
   320 formulas;
   321 
   322 * the simplifier is now installed
   323 
   324 * the axiom system has been generalized (thanks to Soren Heilmann) 
   325 
   326 * the classical reasoner now has a default rule database
   327 
   328 
   329 *** ZF ***
   330 
   331 * new primrec section allows primitive recursive functions to be given
   332 directly (as in HOL) over datatypes and the natural numbers;
   333 
   334 * new tactics induct_tac and exhaust_tac for induction (or case
   335 analysis) over datatypes and the natural numbers;
   336 
   337 * the datatype declaration of type T now defines the recursor T_rec;
   338 
   339 * simplification automatically does freeness reasoning for datatype
   340 constructors;
   341 
   342 * automatic type-inference, with AddTCs command to insert new
   343 type-checking rules;
   344 
   345 * datatype introduction rules are now added as Safe Introduction rules
   346 to the claset;
   347 
   348 * the syntax "if P then x else y" is now available in addition to
   349 if(P,x,y);
   350 
   351 
   352 *** Internal programming interfaces ***
   353 
   354 * tuned simplifier trace output; new flag debug_simp;
   355 
   356 * structures Vartab / Termtab (instances of TableFun) offer efficient
   357 tables indexed by indexname_ord / term_ord (compatible with aconv);
   358 
   359 * AxClass.axclass_tac lost the theory argument;
   360 
   361 * tuned current_goals_markers semantics: begin / end goal avoids
   362 printing empty lines;
   363 
   364 * removed prs and prs_fn hook, which was broken because it did not
   365 include \n in its semantics, forcing writeln to add one
   366 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
   367 string -> unit if you really want to output text without newline;
   368 
   369 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
   370 plain output, interface builders may have to enable 'isabelle_font'
   371 mode to get Isabelle font glyphs as before;
   372 
   373 * refined token_translation interface; INCOMPATIBILITY: output length
   374 now of type real instead of int;
   375 
   376 * theory loader actions may be traced via new ThyInfo.add_hook
   377 interface (see src/Pure/Thy/thy_info.ML); example application: keep
   378 your own database of information attached to *whole* theories -- as
   379 opposed to intra-theory data slots offered via TheoryDataFun;
   380 
   381 * proper handling of dangling sort hypotheses (at last!);
   382 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
   383 extra sort hypotheses that can be witnessed from the type signature;
   384 the force_strip_shyps flag is gone, any remaining shyps are simply
   385 left in the theorem (with a warning issued by strip_shyps_warning);
   386 
   387 
   388 
   389 New in Isabelle98-1 (October 1998)
   390 ----------------------------------
   391 
   392 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   393 
   394 * several changes of automated proof tools;
   395 
   396 * HOL: major changes to the inductive and datatype packages, including
   397 some minor incompatibilities of theory syntax;
   398 
   399 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
   400 called `inj_on';
   401 
   402 * HOL: removed duplicate thms in Arith:
   403   less_imp_add_less  should be replaced by  trans_less_add1
   404   le_imp_add_le      should be replaced by  trans_le_add1
   405 
   406 * HOL: unary minus is now overloaded (new type constraints may be
   407 required);
   408 
   409 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
   410 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
   411 now taken as an integer constant.
   412 
   413 * Pure: ML function 'theory_of' renamed to 'theory';
   414 
   415 
   416 *** Proof tools ***
   417 
   418 * Simplifier:
   419   1. Asm_full_simp_tac is now more aggressive.
   420      1. It will sometimes reorient premises if that increases their power to
   421         simplify.
   422      2. It does no longer proceed strictly from left to right but may also
   423         rotate premises to achieve further simplification.
   424      For compatibility reasons there is now Asm_lr_simp_tac which is like the
   425      old Asm_full_simp_tac in that it does not rotate premises.
   426   2. The simplifier now knows a little bit about nat-arithmetic.
   427 
   428 * Classical reasoner: wrapper mechanism for the classical reasoner now
   429 allows for selected deletion of wrappers, by introduction of names for
   430 wrapper functionals.  This implies that addbefore, addSbefore,
   431 addaltern, and addSaltern now take a pair (name, tactic) as argument,
   432 and that adding two tactics with the same name overwrites the first
   433 one (emitting a warning).
   434   type wrapper = (int -> tactic) -> (int -> tactic)
   435   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
   436   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
   437   delWrapper, delSWrapper: claset *  string            -> claset
   438   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
   439 
   440 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
   441 semantics; addbefore now affects only the unsafe part of step_tac
   442 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
   443 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
   444 by Force_tac;
   445 
   446 * Classical reasoner: setwrapper to setWrapper and compwrapper to
   447 compWrapper; added safe wrapper (and access functions for it);
   448 
   449 * HOL/split_all_tac is now much faster and fails if there is nothing
   450 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
   451 and the names of the automatically generated variables have changed.
   452 split_all_tac has moved within claset() from unsafe wrappers to safe
   453 wrappers, which means that !!-bound variables are split much more
   454 aggressively, and safe_tac and clarify_tac now split such variables.
   455 If this splitting is not appropriate, use delSWrapper "split_all_tac".
   456 Note: the same holds for record_split_tac, which does the job of
   457 split_all_tac for record fields.
   458 
   459 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
   460 permanently to the default simpset using Addsplits just like
   461 Addsimps. They can be removed via Delsplits just like
   462 Delsimps. Lower-case versions are also available.
   463 
   464 * HOL/Simplifier: The rule split_if is now part of the default
   465 simpset. This means that the simplifier will eliminate all occurrences
   466 of if-then-else in the conclusion of a goal. To prevent this, you can
   467 either remove split_if completely from the default simpset by
   468 `Delsplits [split_if]' or remove it in a specific call of the
   469 simplifier using `... delsplits [split_if]'.  You can also add/delete
   470 other case splitting rules to/from the default simpset: every datatype
   471 generates suitable rules `split_t_case' and `split_t_case_asm' (where
   472 t is the name of the datatype).
   473 
   474 * Classical reasoner / Simplifier combination: new force_tac (and
   475 derivatives Force_tac, force) combines rewriting and classical
   476 reasoning (and whatever other tools) similarly to auto_tac, but is
   477 aimed to solve the given subgoal completely.
   478 
   479 
   480 *** General ***
   481 
   482 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
   483 and `goalw': the theory is no longer needed as an explicit argument -
   484 the current theory context is used; assumptions are no longer returned
   485 at the ML-level unless one of them starts with ==> or !!; it is
   486 recommended to convert to these new commands using isatool fixgoal
   487 (backup your sources first!);
   488 
   489 * new top-level commands 'thm' and 'thms' for retrieving theorems from
   490 the current theory context, and 'theory' to lookup stored theories;
   491 
   492 * new theory section 'locale' for declaring constants, assumptions and
   493 definitions that have local scope;
   494 
   495 * new theory section 'nonterminals' for purely syntactic types;
   496 
   497 * new theory section 'setup' for generic ML setup functions
   498 (e.g. package initialization);
   499 
   500 * the distribution now includes Isabelle icons: see
   501 lib/logo/isabelle-{small,tiny}.xpm;
   502 
   503 * isatool install - install binaries with absolute references to
   504 ISABELLE_HOME/bin;
   505 
   506 * isatool logo -- create instances of the Isabelle logo (as EPS);
   507 
   508 * print mode 'emacs' reserved for Isamode;
   509 
   510 * support multiple print (ast) translations per constant name;
   511 
   512 * theorems involving oracles are now printed with a suffixed [!];
   513 
   514 
   515 *** HOL ***
   516 
   517 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
   518 
   519 * HOL/inductive package reorganized and improved: now supports mutual
   520 definitions such as
   521 
   522   inductive EVEN ODD
   523     intrs
   524       null "0 : EVEN"
   525       oddI "n : EVEN ==> Suc n : ODD"
   526       evenI "n : ODD ==> Suc n : EVEN"
   527 
   528 new theorem list "elims" contains an elimination rule for each of the
   529 recursive sets; inductive definitions now handle disjunctive premises
   530 correctly (also ZF);
   531 
   532 INCOMPATIBILITIES: requires Inductive as an ancestor; component
   533 "mutual_induct" no longer exists - the induction rule is always
   534 contained in "induct";
   535 
   536 
   537 * HOL/datatype package re-implemented and greatly improved: now
   538 supports mutually recursive datatypes such as
   539 
   540   datatype
   541     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
   542             | SUM ('a aexp) ('a aexp)
   543             | DIFF ('a aexp) ('a aexp)
   544             | NUM 'a
   545   and
   546     'a bexp = LESS ('a aexp) ('a aexp)
   547             | AND ('a bexp) ('a bexp)
   548             | OR ('a bexp) ('a bexp)
   549 
   550 as well as indirectly recursive datatypes such as
   551 
   552   datatype
   553     ('a, 'b) term = Var 'a
   554                   | App 'b ((('a, 'b) term) list)
   555 
   556 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
   557 induction on mutually / indirectly recursive datatypes.
   558 
   559 Primrec equations are now stored in theory and can be accessed via
   560 <function_name>.simps.
   561 
   562 INCOMPATIBILITIES:
   563 
   564   - Theories using datatypes must now have theory Datatype as an
   565     ancestor.
   566   - The specific <typename>.induct_tac no longer exists - use the
   567     generic induct_tac instead.
   568   - natE has been renamed to nat.exhaust - use exhaust_tac
   569     instead of res_inst_tac ... natE. Note that the variable
   570     names in nat.exhaust differ from the names in natE, this
   571     may cause some "fragile" proofs to fail.
   572   - The theorems split_<typename>_case and split_<typename>_case_asm
   573     have been renamed to <typename>.split and <typename>.split_asm.
   574   - Since default sorts of type variables are now handled correctly,
   575     some datatype definitions may have to be annotated with explicit
   576     sort constraints.
   577   - Primrec definitions no longer require function name and type
   578     of recursive argument.
   579 
   580 Consider using isatool fixdatatype to adapt your theories and proof
   581 scripts to the new package (backup your sources first!).
   582 
   583 
   584 * HOL/record package: considerably improved implementation; now
   585 includes concrete syntax for record types, terms, updates; theorems
   586 for surjective pairing and splitting !!-bound record variables; proof
   587 support is as follows:
   588 
   589   1) standard conversions (selectors or updates applied to record
   590 constructor terms) are part of the standard simpset;
   591 
   592   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
   593 made part of standard simpset and claset via addIffs;
   594 
   595   3) a tactic for record field splitting (record_split_tac) is part of
   596 the standard claset (addSWrapper);
   597 
   598 To get a better idea about these rules you may retrieve them via
   599 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
   600 the name of your record type.
   601 
   602 The split tactic 3) conceptually simplifies by the following rule:
   603 
   604   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
   605 
   606 Thus any record variable that is bound by meta-all will automatically
   607 blow up into some record constructor term, consequently the
   608 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
   609 solve record problems automatically.
   610 
   611 
   612 * reorganized the main HOL image: HOL/Integ and String loaded by
   613 default; theory Main includes everything;
   614 
   615 * automatic simplification of integer sums and comparisons, using cancellation;
   616 
   617 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
   618 
   619 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
   620 
   621 * many new identities for unions, intersections, set difference, etc.;
   622 
   623 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
   624 called split_if, split_split, split_sum_case and split_nat_case (to go
   625 with add/delsplits);
   626 
   627 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
   628 (?x::unit) = (); this is made part of the default simpset, which COULD
   629 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
   630 'Delsimprocs [unit_eq_proc];' as last resort); also note that
   631 unit_abs_eta_conv is added in order to counter the effect of
   632 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
   633 %u.f();
   634 
   635 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
   636 makes more sense);
   637 
   638 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   639   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   640   disjointness reasoning but breaking a few old proofs.
   641 
   642 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
   643 to 'converse' from 'inverse' (for compatibility with ZF and some
   644 literature);
   645 
   646 * HOL/recdef can now declare non-recursive functions, with {} supplied as
   647 the well-founded relation;
   648 
   649 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
   650     Compl A.  The "Compl" syntax remains available as input syntax for this
   651     release ONLY.
   652 
   653 * HOL/Update: new theory of function updates:
   654     f(a:=b) == %x. if x=a then b else f x
   655 may also be iterated as in f(a:=b,c:=d,...);
   656 
   657 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
   658 
   659 * HOL/List:
   660   - new function list_update written xs[i:=v] that updates the i-th
   661     list position. May also be iterated as in xs[i:=a,j:=b,...].
   662   - new function `upt' written [i..j(] which generates the list
   663     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
   664     bound write [i..j], which is a shorthand for [i..j+1(].
   665   - new lexicographic orderings and corresponding wellfoundedness theorems.
   666 
   667 * HOL/Arith:
   668   - removed 'pred' (predecessor) function;
   669   - generalized some theorems about n-1;
   670   - many new laws about "div" and "mod";
   671   - new laws about greatest common divisors (see theory ex/Primes);
   672 
   673 * HOL/Relation: renamed the relational operator r^-1 "converse"
   674 instead of "inverse";
   675 
   676 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
   677   of the multiset ordering;
   678 
   679 * directory HOL/Real: a construction of the reals using Dedekind cuts
   680   (not included by default);
   681 
   682 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
   683 
   684 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
   685   programs, i.e. different program variables may have different types.
   686 
   687 * calling (stac rew i) now fails if "rew" has no effect on the goal
   688   [previously, this check worked only if the rewrite rule was unconditional]
   689   Now rew can involve either definitions or equalities (either == or =).
   690 
   691 
   692 *** ZF ***
   693 
   694 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
   695   only the theorems proved on ZF.ML;
   696 
   697 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   698   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   699   disjointness reasoning but breaking a few old proofs.
   700 
   701 * ZF/Update: new theory of function updates
   702     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
   703   may also be iterated as in f(a:=b,c:=d,...);
   704 
   705 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
   706 
   707 * calling (stac rew i) now fails if "rew" has no effect on the goal
   708   [previously, this check worked only if the rewrite rule was unconditional]
   709   Now rew can involve either definitions or equalities (either == or =).
   710 
   711 * case_tac provided for compatibility with HOL
   712     (like the old excluded_middle_tac, but with subgoals swapped)
   713 
   714 
   715 *** Internal programming interfaces ***
   716 
   717 * Pure: several new basic modules made available for general use, see
   718 also src/Pure/README;
   719 
   720 * improved the theory data mechanism to support encapsulation (data
   721 kind name replaced by private Object.kind, acting as authorization
   722 key); new type-safe user interface via functor TheoryDataFun; generic
   723 print_data function becomes basically useless;
   724 
   725 * removed global_names compatibility flag -- all theory declarations
   726 are qualified by default;
   727 
   728 * module Pure/Syntax now offers quote / antiquote translation
   729 functions (useful for Hoare logic etc. with implicit dependencies);
   730 see HOL/ex/Antiquote for an example use;
   731 
   732 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
   733 cterm -> thm;
   734 
   735 * new tactical CHANGED_GOAL for checking that a tactic modifies a
   736 subgoal;
   737 
   738 * Display.print_goals function moved to Locale.print_goals;
   739 
   740 * standard print function for goals supports current_goals_markers
   741 variable for marking begin of proof, end of proof, start of goal; the
   742 default is ("", "", ""); setting current_goals_markers := ("<proof>",
   743 "</proof>", "<goal>") causes SGML like tagged proof state printing,
   744 for example;
   745 
   746 
   747 
   748 New in Isabelle98 (January 1998)
   749 --------------------------------
   750 
   751 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   752 
   753 * changed lexical syntax of terms / types: dots made part of long
   754 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
   755 
   756 * simpset (and claset) reference variable replaced by functions
   757 simpset / simpset_ref;
   758 
   759 * no longer supports theory aliases (via merge) and non-trivial
   760 implicit merge of thms' signatures;
   761 
   762 * most internal names of constants changed due to qualified names;
   763 
   764 * changed Pure/Sequence interface (see Pure/seq.ML);
   765 
   766 
   767 *** General Changes ***
   768 
   769 * hierachically structured name spaces (for consts, types, axms, thms
   770 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
   771 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
   772 isatool fixdots ensures space after dots (e.g. "%x. x"); set
   773 long_names for fully qualified output names; NOTE: ML programs
   774 (special tactics, packages etc.) referring to internal names may have
   775 to be adapted to cope with fully qualified names; in case of severe
   776 backward campatibility problems try setting 'global_names' at compile
   777 time to have enrything declared within a flat name space; one may also
   778 fine tune name declarations in theories via the 'global' and 'local'
   779 section;
   780 
   781 * reimplemented the implicit simpset and claset using the new anytype
   782 data filed in signatures; references simpset:simpset ref etc. are
   783 replaced by functions simpset:unit->simpset and
   784 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
   785 to patch your ML files accordingly;
   786 
   787 * HTML output now includes theory graph data for display with Java
   788 applet or isatool browser; data generated automatically via isatool
   789 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
   790 
   791 * defs may now be conditional; improved rewrite_goals_tac to handle
   792 conditional equations;
   793 
   794 * defs now admits additional type arguments, using TYPE('a) syntax;
   795 
   796 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
   797 creates a new theory node; implicit merge of thms' signatures is
   798 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
   799 transfer:theory->thm->thm in (rare) cases;
   800 
   801 * improved handling of draft signatures / theories; draft thms (and
   802 ctyps, cterms) are automatically promoted to real ones;
   803 
   804 * slightly changed interfaces for oracles: admit many per theory, named
   805 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
   806 
   807 * print_goals: optional output of const types (set show_consts and
   808 show_types);
   809 
   810 * improved output of warnings (###) and errors (***);
   811 
   812 * subgoal_tac displays a warning if the new subgoal has type variables;
   813 
   814 * removed old README and Makefiles;
   815 
   816 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
   817 
   818 * removed obsolete init_pps and init_database;
   819 
   820 * deleted the obsolete tactical STATE, which was declared by
   821     fun STATE tacfun st = tacfun st st;
   822 
   823 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
   824 (which abbreviates $HOME);
   825 
   826 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
   827 use isatool fixseq to adapt your ML programs (this works for fully
   828 qualified references to the Sequence structure only!);
   829 
   830 * use_thy no longer requires writable current directory; it always
   831 reloads .ML *and* .thy file, if either one is out of date;
   832 
   833 
   834 *** Classical Reasoner ***
   835 
   836 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
   837 tactics that use classical reasoning to simplify a subgoal without
   838 splitting it into several subgoals;
   839 
   840 * Safe_tac: like safe_tac but uses the default claset;
   841 
   842 
   843 *** Simplifier ***
   844 
   845 * added simplification meta rules:
   846     (asm_)(full_)simplify: simpset -> thm -> thm;
   847 
   848 * simplifier.ML no longer part of Pure -- has to be loaded by object
   849 logics (again);
   850 
   851 * added prems argument to simplification procedures;
   852 
   853 * HOL, FOL, ZF: added infix function `addsplits':
   854   instead of `<simpset> setloop (split_tac <thms>)'
   855   you can simply write `<simpset> addsplits <thms>'
   856 
   857 
   858 *** Syntax ***
   859 
   860 * TYPE('a) syntax for type reflection terms;
   861 
   862 * no longer handles consts with name "" -- declare as 'syntax' instead;
   863 
   864 * pretty printer: changed order of mixfix annotation preference (again!);
   865 
   866 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
   867 
   868 
   869 *** HOL ***
   870 
   871 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
   872   with `addloop' of the simplifier to faciliate case splitting in premises.
   873 
   874 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
   875 
   876 * HOL/Auth: new protocol proofs including some for the Internet
   877   protocol TLS;
   878 
   879 * HOL/Map: new theory of `maps' a la VDM;
   880 
   881 * HOL/simplifier: simplification procedures nat_cancel_sums for
   882 cancelling out common nat summands from =, <, <= (in)equalities, or
   883 differences; simplification procedures nat_cancel_factor for
   884 cancelling common factor from =, <, <= (in)equalities over natural
   885 sums; nat_cancel contains both kinds of procedures, it is installed by
   886 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
   887 
   888 * HOL/simplifier: terms of the form
   889   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
   890   are rewritten to
   891   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
   892   and those of the form
   893   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
   894   are rewritten to
   895   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
   896 
   897 * HOL/datatype
   898   Each datatype `t' now comes with a theorem `split_t_case' of the form
   899 
   900   P(t_case f1 ... fn x) =
   901      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
   902         ...
   903        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
   904      )
   905 
   906   and a theorem `split_t_case_asm' of the form
   907 
   908   P(t_case f1 ... fn x) =
   909     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
   910         ...
   911        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
   912      )
   913   which can be added to a simpset via `addsplits'. The existing theorems
   914   expand_list_case and expand_option_case have been renamed to
   915   split_list_case and split_option_case.
   916 
   917 * HOL/Arithmetic:
   918   - `pred n' is automatically converted to `n-1'.
   919     Users are strongly encouraged not to use `pred' any longer,
   920     because it will disappear altogether at some point.
   921   - Users are strongly encouraged to write "0 < n" rather than
   922     "n ~= 0". Theorems and proof tools have been modified towards this
   923     `standard'.
   924 
   925 * HOL/Lists:
   926   the function "set_of_list" has been renamed "set" (and its theorems too);
   927   the function "nth" now takes its arguments in the reverse order and
   928   has acquired the infix notation "!" as in "xs!n".
   929 
   930 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
   931 
   932 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
   933   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
   934 
   935 * HOL/record: extensible records with schematic structural subtyping
   936 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
   937 still lacks various theorems and concrete record syntax;
   938 
   939 
   940 *** HOLCF ***
   941 
   942 * removed "axioms" and "generated by" sections;
   943 
   944 * replaced "ops" section by extended "consts" section, which is capable of
   945   handling the continuous function space "->" directly;
   946 
   947 * domain package:
   948   . proves theorems immediately and stores them in the theory,
   949   . creates hierachical name space,
   950   . now uses normal mixfix annotations (instead of cinfix...),
   951   . minor changes to some names and values (for consistency),
   952   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
   953   . separator between mutual domain defs: changed "," to "and",
   954   . improved handling of sort constraints;  now they have to
   955     appear on the left-hand side of the equations only;
   956 
   957 * fixed LAM <x,y,zs>.b syntax;
   958 
   959 * added extended adm_tac to simplifier in HOLCF -- can now discharge
   960 adm (%x. P (t x)), where P is chainfinite and t continuous;
   961 
   962 
   963 *** FOL and ZF ***
   964 
   965 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
   966   with `addloop' of the simplifier to faciliate case splitting in premises.
   967 
   968 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
   969 in HOL, they strip ALL and --> from proved theorems;
   970 
   971 
   972 
   973 New in Isabelle94-8 (May 1997)
   974 ------------------------------
   975 
   976 *** General Changes ***
   977 
   978 * new utilities to build / run / maintain Isabelle etc. (in parts
   979 still somewhat experimental); old Makefiles etc. still functional;
   980 
   981 * new 'Isabelle System Manual';
   982 
   983 * INSTALL text, together with ./configure and ./build scripts;
   984 
   985 * reimplemented type inference for greater efficiency, better error
   986 messages and clean internal interface;
   987 
   988 * prlim command for dealing with lots of subgoals (an easier way of
   989 setting goals_limit);
   990 
   991 
   992 *** Syntax ***
   993 
   994 * supports alternative (named) syntax tables (parser and pretty
   995 printer); internal interface is provided by add_modesyntax(_i);
   996 
   997 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
   998 be used in conjunction with the Isabelle symbol font; uses the
   999 "symbols" syntax table;
  1000 
  1001 * added token_translation interface (may translate name tokens in
  1002 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  1003 the current print_mode); IMPORTANT: user print translation functions
  1004 are responsible for marking newly introduced bounds
  1005 (Syntax.mark_boundT);
  1006 
  1007 * token translations for modes "xterm" and "xterm_color" that display
  1008 names in bold, underline etc. or colors (which requires a color
  1009 version of xterm);
  1010 
  1011 * infixes may now be declared with names independent of their syntax;
  1012 
  1013 * added typed_print_translation (like print_translation, but may
  1014 access type of constant);
  1015 
  1016 
  1017 *** Classical Reasoner ***
  1018 
  1019 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  1020 some limitations.  Blast_tac...
  1021   + ignores addss, addbefore, addafter; this restriction is intrinsic
  1022   + ignores elimination rules that don't have the correct format
  1023         (the conclusion MUST be a formula variable)
  1024   + ignores types, which can make HOL proofs fail
  1025   + rules must not require higher-order unification, e.g. apply_type in ZF
  1026     [message "Function Var's argument not a bound variable" relates to this]
  1027   + its proof strategy is more general but can actually be slower
  1028 
  1029 * substitution with equality assumptions no longer permutes other
  1030 assumptions;
  1031 
  1032 * minor changes in semantics of addafter (now called addaltern); renamed
  1033 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  1034 (and access functions for it);
  1035 
  1036 * improved combination of classical reasoner and simplifier:
  1037   + functions for handling clasimpsets
  1038   + improvement of addss: now the simplifier is called _after_ the
  1039     safe steps.
  1040   + safe variant of addss called addSss: uses safe simplifications
  1041     _during_ the safe steps. It is more complete as it allows multiple
  1042     instantiations of unknowns (e.g. with slow_tac).
  1043 
  1044 *** Simplifier ***
  1045 
  1046 * added interface for simplification procedures (functions that
  1047 produce *proven* rewrite rules on the fly, depending on current
  1048 redex);
  1049 
  1050 * ordering on terms as parameter (used for ordered rewriting);
  1051 
  1052 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  1053 
  1054 * the solver is now split into a safe and an unsafe part.
  1055 This should be invisible for the normal user, except that the
  1056 functions setsolver and addsolver have been renamed to setSolver and
  1057 addSolver; added safe_asm_full_simp_tac;
  1058 
  1059 
  1060 *** HOL ***
  1061 
  1062 * a generic induction tactic `induct_tac' which works for all datatypes and
  1063 also for type `nat';
  1064 
  1065 * a generic case distinction tactic `exhaust_tac' which works for all
  1066 datatypes and also for type `nat';
  1067 
  1068 * each datatype comes with a function `size';
  1069 
  1070 * patterns in case expressions allow tuple patterns as arguments to
  1071 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  1072 
  1073 * primrec now also works with type nat;
  1074 
  1075 * recdef: a new declaration form, allows general recursive functions to be
  1076 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  1077 
  1078 * the constant for negation has been renamed from "not" to "Not" to
  1079 harmonize with FOL, ZF, LK, etc.;
  1080 
  1081 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  1082 infinite lists;
  1083 
  1084 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  1085 
  1086 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  1087 problems in commutative rings, using axiomatic type classes for + and *;
  1088 
  1089 * more examples in HOL/MiniML and HOL/Auth;
  1090 
  1091 * more default rewrite rules for quantifiers, union/intersection;
  1092 
  1093 * a new constant `arbitrary == @x.False';
  1094 
  1095 * HOLCF/IOA replaces old HOL/IOA;
  1096 
  1097 * HOLCF changes: derived all rules and arities
  1098   + axiomatic type classes instead of classes
  1099   + typedef instead of faking type definitions
  1100   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  1101   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  1102   + eliminated the types void, one, tr
  1103   + use unit lift and bool lift (with translations) instead of one and tr
  1104   + eliminated blift from Lift3.thy (use Def instead of blift)
  1105   all eliminated rules are derived as theorems --> no visible changes ;
  1106 
  1107 
  1108 *** ZF ***
  1109 
  1110 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  1111 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  1112 as ZF_cs addSIs [equalityI];
  1113 
  1114 
  1115 
  1116 New in Isabelle94-7 (November 96)
  1117 ---------------------------------
  1118 
  1119 * allowing negative levels (as offsets) in prlev and choplev;
  1120 
  1121 * super-linear speedup for large simplifications;
  1122 
  1123 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  1124 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  1125 FAIL); can suppress it using the command Delsimps (ex_simps @
  1126 all_simps); De Morgan laws are also now included, by default;
  1127 
  1128 * improved printing of ==>  :  ~:
  1129 
  1130 * new object-logic "Sequents" adds linear logic, while replacing LK
  1131 and Modal (thanks to Sara Kalvala);
  1132 
  1133 * HOL/Auth: correctness proofs for authentication protocols;
  1134 
  1135 * HOL: new auto_tac combines rewriting and classical reasoning (many
  1136 examples on HOL/Auth);
  1137 
  1138 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  1139 the rewriter and classical reasoner simultaneously;
  1140 
  1141 * function uresult no longer returns theorems in "standard" format;
  1142 regain previous version by: val uresult = standard o uresult;
  1143 
  1144 
  1145 
  1146 New in Isabelle94-6
  1147 -------------------
  1148 
  1149 * oracles -- these establish an interface between Isabelle and trusted
  1150 external reasoners, which may deliver results as theorems;
  1151 
  1152 * proof objects (in particular record all uses of oracles);
  1153 
  1154 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  1155 
  1156 * "constdefs" section in theory files;
  1157 
  1158 * "primrec" section (HOL) no longer requires names;
  1159 
  1160 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  1161 
  1162 
  1163 
  1164 New in Isabelle94-5
  1165 -------------------
  1166 
  1167 * reduced space requirements;
  1168 
  1169 * automatic HTML generation from theories;
  1170 
  1171 * theory files no longer require "..." (quotes) around most types;
  1172 
  1173 * new examples, including two proofs of the Church-Rosser theorem;
  1174 
  1175 * non-curried (1994) version of HOL is no longer distributed;
  1176 
  1177 
  1178 
  1179 New in Isabelle94-4
  1180 -------------------
  1181 
  1182 * greatly reduced space requirements;
  1183 
  1184 * theory files (.thy) no longer require \...\ escapes at line breaks;
  1185 
  1186 * searchable theorem database (see the section "Retrieving theorems" on
  1187 page 8 of the Reference Manual);
  1188 
  1189 * new examples, including Grabczewski's monumental case study of the
  1190 Axiom of Choice;
  1191 
  1192 * The previous version of HOL renamed to Old_HOL;
  1193 
  1194 * The new version of HOL (previously called CHOL) uses a curried syntax
  1195 for functions.  Application looks like f a b instead of f(a,b);
  1196 
  1197 * Mutually recursive inductive definitions finally work in HOL;
  1198 
  1199 * In ZF, pattern-matching on tuples is now available in all abstractions and
  1200 translates to the operator "split";
  1201 
  1202 
  1203 
  1204 New in Isabelle94-3
  1205 -------------------
  1206 
  1207 * new infix operator, addss, allowing the classical reasoner to
  1208 perform simplification at each step of its search.  Example:
  1209         fast_tac (cs addss ss)
  1210 
  1211 * a new logic, CHOL, the same as HOL, but with a curried syntax
  1212 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  1213 look like (a,b) instead of <a,b>;
  1214 
  1215 * PLEASE NOTE: CHOL will eventually replace HOL!
  1216 
  1217 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  1218 It translates to the operator "split".  A new theory of integers is available;
  1219 
  1220 * In ZF, integer numerals now denote two's-complement binary integers.
  1221 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  1222 
  1223 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  1224 of the Axiom of Choice;
  1225 
  1226 
  1227 
  1228 New in Isabelle94-2
  1229 -------------------
  1230 
  1231 * Significantly faster resolution;
  1232 
  1233 * the different sections in a .thy file can now be mixed and repeated
  1234 freely;
  1235 
  1236 * Database of theorems for FOL, HOL and ZF.  New
  1237 commands including qed, qed_goal and bind_thm store theorems in the database.
  1238 
  1239 * Simple database queries: return a named theorem (get_thm) or all theorems of
  1240 a given theory (thms_of), or find out what theory a theorem was proved in
  1241 (theory_of_thm);
  1242 
  1243 * Bugs fixed in the inductive definition and datatype packages;
  1244 
  1245 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  1246 and HOL_dup_cs obsolete;
  1247 
  1248 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  1249 have been removed;
  1250 
  1251 * Simpler definition of function space in ZF;
  1252 
  1253 * new results about cardinal and ordinal arithmetic in ZF;
  1254 
  1255 * 'subtype' facility in HOL for introducing new types as subsets of existing
  1256 types;
  1257 
  1258 
  1259 $Id$