NEWS
author wenzelm
Mon Mar 13 13:34:09 2000 +0100 (2000-03-13)
changeset 8440 d66f0f14b1ca
parent 8425 f03c667cf702
child 8487 5f3b0e02ec15
permissions -rw-r--r--
* HOL: exhaust_tac on datatypes superceded by new case_tac;
* ML: PureThy.add_thms/add_axioms/add_defs now return theorems;
* Isar/Pure: much better support for case-analysis;
* ML: new combinators |>> and |>>>
     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 constant for f``x is now "image" rather than "op ``".
    11 
    12 * HOL: exhaust_tac on datatypes superceded by new case_tac;
    13 
    14 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems;
    15 
    16 
    17 *** Isabelle document preparation ***
    18 
    19 * isatool mkdir provides easy setup of Isabelle session directories,
    20 including proper documents;
    21 
    22 * generated LaTeX sources are now deleted after successful run
    23 (isatool document -c); may retain a copy somewhere else via -D option
    24 of isatool usedir;
    25 
    26 * old-style theories now produce (crude) LaTeX sources as well;
    27 
    28 
    29 *** Isar ***
    30 
    31 * Pure now provides its own version of intro/elim/dest attributes;
    32 useful for building new logics, but beware of confusion with the
    33 Provers/classical ones!
    34 
    35 * Pure: new 'obtain' language element supports generalized existence
    36 proofs;
    37 
    38 * Pure: much better support for case-analysis type proofs: new 'case'
    39 language element refers to local contexts symbolically, as produced by
    40 certain proof methods; internally, case names are attached to theorems
    41 as "tags";
    42 
    43 * HOL: new proof method 'cases' and improved version of 'induct' now
    44 support named cases; major packages (inductive, datatype, primrec,
    45 recdef) support case names and properly name parameters;
    46 
    47 * HOL: removed 'case_split' thm binding, should use 'cases' proof
    48 method anyway;
    49 
    50 * names of theorems etc. may be natural numbers as well;
    51 
    52 * intro/elim/dest attributes: changed ! / !! flags to ? / ??;
    53 
    54 
    55 *** HOL ***
    56 
    57 * Algebra: new theory of rings and univariate polynomials, by Clemens
    58 Ballarin;
    59 
    60 * HOL/record: fixed select-update simplification procedure to handle
    61 extended records as well; admit "r" as field name;
    62 
    63 * HOL/ex: new theory Factorization proving the Fundamental Theorem of
    64 Arithmetic, by Thomas M Rasmussen;
    65 
    66 * new version of "case_tac" subsumes both boolean case split and
    67 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
    68 exists, may define val exhaust_tac = case_tac for quick-and-dirty
    69 portability;
    70 
    71 
    72 *** General ***
    73 
    74 * compression of ML heaps images may now be controlled via -c option
    75 of isabelle and isatool usedir;
    76 
    77 * new ML combinators |>> and |>>> for incremental transformations with
    78 secondary results (e.g. certain theory extensions):
    79 
    80 
    81 
    82 
    83 New in Isabelle99 (October 1999)
    84 --------------------------------
    85 
    86 *** Overview of INCOMPATIBILITIES (see below for more details) ***
    87 
    88 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
    89 are no longer simplified.  (This allows the simplifier to unfold recursive
    90 functional programs.)  To restore the old behaviour, declare
    91 
    92     Delcongs [if_weak_cong];
    93 
    94 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
    95 complement;
    96 
    97 * HOL: the predicate "inj" is now defined by translation to "inj_on";
    98 
    99 * HOL/datatype: mutual_induct_tac no longer exists --
   100   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
   101 
   102 * HOL/typedef: fixed type inference for representing set; type
   103 arguments now have to occur explicitly on the rhs as type constraints;
   104 
   105 * ZF: The con_defs part of an inductive definition may no longer refer
   106 to constants declared in the same theory;
   107 
   108 * HOL, ZF: the function mk_cases, generated by the inductive
   109 definition package, has lost an argument.  To simplify its result, it
   110 uses the default simpset instead of a supplied list of theorems.
   111 
   112 * HOL/List: the constructors of type list are now Nil and Cons;
   113 
   114 * Simplifier: the type of the infix ML functions
   115 	setSSolver addSSolver setSolver addSolver
   116 is now  simpset * solver -> simpset  where `solver' is a new abstract type
   117 for packaging solvers. A solver is created via
   118 	mk_solver: string -> (thm list -> int -> tactic) -> solver
   119 where the string argument is only a comment.
   120 
   121 
   122 *** Proof tools ***
   123 
   124 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
   125 decision procedure for linear arithmetic. Currently it is used for
   126 types `nat', `int', and `real' in HOL (see below); it can, should and
   127 will be instantiated for other types and logics as well.
   128 
   129 * The simplifier now accepts rewrite rules with flexible heads, eg
   130      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
   131   They are applied like any rule with a non-pattern lhs, i.e. by first-order
   132   matching.
   133 
   134 
   135 *** General ***
   136 
   137 * New Isabelle/Isar subsystem provides an alternative to traditional
   138 tactical theorem proving; together with the ProofGeneral/isar user
   139 interface it offers an interactive environment for developing human
   140 readable proof documents (Isar == Intelligible semi-automated
   141 reasoning); for further information see isatool doc isar-ref,
   142 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
   143 
   144 * improved presentation of theories: better HTML markup (including
   145 colors), graph views in several sizes; isatool usedir now provides a
   146 proper interface for user theories (via -P option); actual document
   147 preparation based on (PDF)LaTeX is available as well (for new-style
   148 theories only); see isatool doc system for more information;
   149 
   150 * native support for Proof General, both for classic Isabelle and
   151 Isabelle/Isar;
   152 
   153 * ML function thm_deps visualizes dependencies of theorems and lemmas,
   154 using the graph browser tool;
   155 
   156 * Isabelle manuals now also available as PDF;
   157 
   158 * theory loader rewritten from scratch (may not be fully
   159 bug-compatible); old loadpath variable has been replaced by show_path,
   160 add_path, del_path, reset_path functions; new operations such as
   161 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
   162 isatool doc ref);
   163 
   164 * improved isatool install: option -k creates KDE application icon,
   165 option -p DIR installs standalone binaries;
   166 
   167 * added ML_PLATFORM setting (useful for cross-platform installations);
   168 more robust handling of platform specific ML images for SML/NJ;
   169 
   170 * the settings environment is now statically scoped, i.e. it is never
   171 created again in sub-processes invoked from isabelle, isatool, or
   172 Isabelle;
   173 
   174 * path element specification '~~' refers to '$ISABELLE_HOME';
   175 
   176 * in locales, the "assumes" and "defines" parts may be omitted if
   177 empty;
   178 
   179 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
   180 long arrows);
   181 
   182 * new print_mode "HTML";
   183 
   184 * new flag show_tags controls display of tags of theorems (which are
   185 basically just comments that may be attached by some tools);
   186 
   187 * Isamode 2.6 requires patch to accomodate change of Isabelle font
   188 mode and goal output format:
   189 
   190 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
   191 244c244
   192 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
   193 ---
   194 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
   195 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
   196 181c181
   197 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
   198 ---
   199 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
   200 
   201 * function bind_thms stores lists of theorems (cf. bind_thm);
   202 
   203 * new shorthand tactics ftac, eatac, datac, fatac;
   204 
   205 * qed (and friends) now accept "" as result name; in that case the
   206 theorem is not stored, but proper checks and presentation of the
   207 result still apply;
   208 
   209 * theorem database now also indexes constants "Trueprop", "all",
   210 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
   211 
   212 
   213 *** HOL ***
   214 
   215 ** HOL arithmetic **
   216 
   217 * There are now decision procedures for linear arithmetic over nat and
   218 int:
   219 
   220 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
   221 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
   222 are treated as atomic; subformulae not involving type `nat' or `int'
   223 are ignored; quantified subformulae are ignored unless they are
   224 positive universal or negative existential. The tactic has to be
   225 invoked by hand and can be a little bit slow. In particular, the
   226 running time is exponential in the number of occurrences of `min' and
   227 `max', and `-' on `nat'.
   228 
   229 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
   230 (negated) (in)equalities among the premises and the conclusion into
   231 account (i.e. no compound formulae) and does not know about `min' and
   232 `max', and `-' on `nat'. It is fast and is used automatically by the
   233 simplifier.
   234 
   235 NB: At the moment, these decision procedures do not cope with mixed
   236 nat/int formulae where the two parts interact, such as `m < n ==>
   237 int(m) < int(n)'.
   238 
   239 * HOL/Numeral provides a generic theory of numerals (encoded
   240 efficiently as bit strings); setup for types nat/int/real is in place;
   241 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
   242 int, existing theories and proof scripts may require a few additional
   243 type constraints;
   244 
   245 * integer division and remainder can now be performed on constant
   246 arguments;
   247 
   248 * many properties of integer multiplication, division and remainder
   249 are now available;
   250 
   251 * An interface to the Stanford Validity Checker (SVC) is available through the
   252 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
   253 are proved automatically.  SVC must be installed separately, and its results
   254 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
   255 invocation of the underlying oracle).  For SVC see
   256   http://verify.stanford.edu/SVC
   257 
   258 * IsaMakefile: the HOL-Real target now builds an actual image;
   259 
   260 
   261 ** HOL misc **
   262 
   263 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
   264 (in Isabelle/Isar) -- by Gertrud Bauer;
   265 
   266 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
   267 analysis for assembly languages with subtypes;
   268 
   269 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
   270 -- avoids syntactic ambiguities and treats state, transition, and
   271 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
   272 changed syntax and (many) tactics;
   273 
   274 * HOL/inductive: Now also handles more general introduction rules such
   275   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
   276   theorems are now maintained within the theory (maintained via the
   277   "mono" attribute);
   278 
   279 * HOL/datatype: Now also handles arbitrarily branching datatypes
   280   (using function types) such as
   281 
   282   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
   283 
   284 * HOL/record: record_simproc (part of the default simpset) takes care
   285 of selectors applied to updated records; record_split_tac is no longer
   286 part of the default claset; update_defs may now be removed from the
   287 simpset in many cases; COMPATIBILITY: old behavior achieved by
   288 
   289   claset_ref () := claset() addSWrapper record_split_wrapper;
   290   Delsimprocs [record_simproc]
   291 
   292 * HOL/typedef: fixed type inference for representing set; type
   293 arguments now have to occur explicitly on the rhs as type constraints;
   294 
   295 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
   296 names rather than an ML expression;
   297 
   298 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
   299 supplied later.  Program schemes can be defined, such as
   300     "While B C s = (if B s then While B C (C s) else s)"
   301 where the well-founded relation can be chosen after B and C have been given.
   302 
   303 * HOL/List: the constructors of type list are now Nil and Cons;
   304 INCOMPATIBILITY: while [] and infix # syntax is still there, of
   305 course, ML tools referring to List.list.op # etc. have to be adapted;
   306 
   307 * HOL_quantifiers flag superseded by "HOL" print mode, which is
   308 disabled by default; run isabelle with option -m HOL to get back to
   309 the original Gordon/HOL-style output;
   310 
   311 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
   312 ALL x<=y. P, EX x<y. P, EX x<=y. P;
   313 
   314 * HOL basic syntax simplified (more orthogonal): all variants of
   315 All/Ex now support plain / symbolic / HOL notation; plain syntax for
   316 Eps operator is provided as well: "SOME x. P[x]";
   317 
   318 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
   319 
   320 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
   321 thus available for user theories;
   322 
   323 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
   324 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
   325 time;
   326 
   327 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
   328 several times and then mp;
   329 
   330 
   331 *** LK ***
   332 
   333 * the notation <<...>> is now available as a notation for sequences of
   334 formulas;
   335 
   336 * the simplifier is now installed
   337 
   338 * the axiom system has been generalized (thanks to Soren Heilmann) 
   339 
   340 * the classical reasoner now has a default rule database
   341 
   342 
   343 *** ZF ***
   344 
   345 * new primrec section allows primitive recursive functions to be given
   346 directly (as in HOL) over datatypes and the natural numbers;
   347 
   348 * new tactics induct_tac and exhaust_tac for induction (or case
   349 analysis) over datatypes and the natural numbers;
   350 
   351 * the datatype declaration of type T now defines the recursor T_rec;
   352 
   353 * simplification automatically does freeness reasoning for datatype
   354 constructors;
   355 
   356 * automatic type-inference, with AddTCs command to insert new
   357 type-checking rules;
   358 
   359 * datatype introduction rules are now added as Safe Introduction rules
   360 to the claset;
   361 
   362 * the syntax "if P then x else y" is now available in addition to
   363 if(P,x,y);
   364 
   365 
   366 *** Internal programming interfaces ***
   367 
   368 * tuned simplifier trace output; new flag debug_simp;
   369 
   370 * structures Vartab / Termtab (instances of TableFun) offer efficient
   371 tables indexed by indexname_ord / term_ord (compatible with aconv);
   372 
   373 * AxClass.axclass_tac lost the theory argument;
   374 
   375 * tuned current_goals_markers semantics: begin / end goal avoids
   376 printing empty lines;
   377 
   378 * removed prs and prs_fn hook, which was broken because it did not
   379 include \n in its semantics, forcing writeln to add one
   380 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
   381 string -> unit if you really want to output text without newline;
   382 
   383 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
   384 plain output, interface builders may have to enable 'isabelle_font'
   385 mode to get Isabelle font glyphs as before;
   386 
   387 * refined token_translation interface; INCOMPATIBILITY: output length
   388 now of type real instead of int;
   389 
   390 * theory loader actions may be traced via new ThyInfo.add_hook
   391 interface (see src/Pure/Thy/thy_info.ML); example application: keep
   392 your own database of information attached to *whole* theories -- as
   393 opposed to intra-theory data slots offered via TheoryDataFun;
   394 
   395 * proper handling of dangling sort hypotheses (at last!);
   396 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
   397 extra sort hypotheses that can be witnessed from the type signature;
   398 the force_strip_shyps flag is gone, any remaining shyps are simply
   399 left in the theorem (with a warning issued by strip_shyps_warning);
   400 
   401 
   402 
   403 New in Isabelle98-1 (October 1998)
   404 ----------------------------------
   405 
   406 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   407 
   408 * several changes of automated proof tools;
   409 
   410 * HOL: major changes to the inductive and datatype packages, including
   411 some minor incompatibilities of theory syntax;
   412 
   413 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
   414 called `inj_on';
   415 
   416 * HOL: removed duplicate thms in Arith:
   417   less_imp_add_less  should be replaced by  trans_less_add1
   418   le_imp_add_le      should be replaced by  trans_le_add1
   419 
   420 * HOL: unary minus is now overloaded (new type constraints may be
   421 required);
   422 
   423 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
   424 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
   425 now taken as an integer constant.
   426 
   427 * Pure: ML function 'theory_of' renamed to 'theory';
   428 
   429 
   430 *** Proof tools ***
   431 
   432 * Simplifier:
   433   1. Asm_full_simp_tac is now more aggressive.
   434      1. It will sometimes reorient premises if that increases their power to
   435         simplify.
   436      2. It does no longer proceed strictly from left to right but may also
   437         rotate premises to achieve further simplification.
   438      For compatibility reasons there is now Asm_lr_simp_tac which is like the
   439      old Asm_full_simp_tac in that it does not rotate premises.
   440   2. The simplifier now knows a little bit about nat-arithmetic.
   441 
   442 * Classical reasoner: wrapper mechanism for the classical reasoner now
   443 allows for selected deletion of wrappers, by introduction of names for
   444 wrapper functionals.  This implies that addbefore, addSbefore,
   445 addaltern, and addSaltern now take a pair (name, tactic) as argument,
   446 and that adding two tactics with the same name overwrites the first
   447 one (emitting a warning).
   448   type wrapper = (int -> tactic) -> (int -> tactic)
   449   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
   450   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
   451   delWrapper, delSWrapper: claset *  string            -> claset
   452   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
   453 
   454 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
   455 semantics; addbefore now affects only the unsafe part of step_tac
   456 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
   457 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
   458 by Force_tac;
   459 
   460 * Classical reasoner: setwrapper to setWrapper and compwrapper to
   461 compWrapper; added safe wrapper (and access functions for it);
   462 
   463 * HOL/split_all_tac is now much faster and fails if there is nothing
   464 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
   465 and the names of the automatically generated variables have changed.
   466 split_all_tac has moved within claset() from unsafe wrappers to safe
   467 wrappers, which means that !!-bound variables are split much more
   468 aggressively, and safe_tac and clarify_tac now split such variables.
   469 If this splitting is not appropriate, use delSWrapper "split_all_tac".
   470 Note: the same holds for record_split_tac, which does the job of
   471 split_all_tac for record fields.
   472 
   473 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
   474 permanently to the default simpset using Addsplits just like
   475 Addsimps. They can be removed via Delsplits just like
   476 Delsimps. Lower-case versions are also available.
   477 
   478 * HOL/Simplifier: The rule split_if is now part of the default
   479 simpset. This means that the simplifier will eliminate all occurrences
   480 of if-then-else in the conclusion of a goal. To prevent this, you can
   481 either remove split_if completely from the default simpset by
   482 `Delsplits [split_if]' or remove it in a specific call of the
   483 simplifier using `... delsplits [split_if]'.  You can also add/delete
   484 other case splitting rules to/from the default simpset: every datatype
   485 generates suitable rules `split_t_case' and `split_t_case_asm' (where
   486 t is the name of the datatype).
   487 
   488 * Classical reasoner / Simplifier combination: new force_tac (and
   489 derivatives Force_tac, force) combines rewriting and classical
   490 reasoning (and whatever other tools) similarly to auto_tac, but is
   491 aimed to solve the given subgoal completely.
   492 
   493 
   494 *** General ***
   495 
   496 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
   497 and `goalw': the theory is no longer needed as an explicit argument -
   498 the current theory context is used; assumptions are no longer returned
   499 at the ML-level unless one of them starts with ==> or !!; it is
   500 recommended to convert to these new commands using isatool fixgoal
   501 (backup your sources first!);
   502 
   503 * new top-level commands 'thm' and 'thms' for retrieving theorems from
   504 the current theory context, and 'theory' to lookup stored theories;
   505 
   506 * new theory section 'locale' for declaring constants, assumptions and
   507 definitions that have local scope;
   508 
   509 * new theory section 'nonterminals' for purely syntactic types;
   510 
   511 * new theory section 'setup' for generic ML setup functions
   512 (e.g. package initialization);
   513 
   514 * the distribution now includes Isabelle icons: see
   515 lib/logo/isabelle-{small,tiny}.xpm;
   516 
   517 * isatool install - install binaries with absolute references to
   518 ISABELLE_HOME/bin;
   519 
   520 * isatool logo -- create instances of the Isabelle logo (as EPS);
   521 
   522 * print mode 'emacs' reserved for Isamode;
   523 
   524 * support multiple print (ast) translations per constant name;
   525 
   526 * theorems involving oracles are now printed with a suffixed [!];
   527 
   528 
   529 *** HOL ***
   530 
   531 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
   532 
   533 * HOL/inductive package reorganized and improved: now supports mutual
   534 definitions such as
   535 
   536   inductive EVEN ODD
   537     intrs
   538       null "0 : EVEN"
   539       oddI "n : EVEN ==> Suc n : ODD"
   540       evenI "n : ODD ==> Suc n : EVEN"
   541 
   542 new theorem list "elims" contains an elimination rule for each of the
   543 recursive sets; inductive definitions now handle disjunctive premises
   544 correctly (also ZF);
   545 
   546 INCOMPATIBILITIES: requires Inductive as an ancestor; component
   547 "mutual_induct" no longer exists - the induction rule is always
   548 contained in "induct";
   549 
   550 
   551 * HOL/datatype package re-implemented and greatly improved: now
   552 supports mutually recursive datatypes such as
   553 
   554   datatype
   555     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
   556             | SUM ('a aexp) ('a aexp)
   557             | DIFF ('a aexp) ('a aexp)
   558             | NUM 'a
   559   and
   560     'a bexp = LESS ('a aexp) ('a aexp)
   561             | AND ('a bexp) ('a bexp)
   562             | OR ('a bexp) ('a bexp)
   563 
   564 as well as indirectly recursive datatypes such as
   565 
   566   datatype
   567     ('a, 'b) term = Var 'a
   568                   | App 'b ((('a, 'b) term) list)
   569 
   570 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
   571 induction on mutually / indirectly recursive datatypes.
   572 
   573 Primrec equations are now stored in theory and can be accessed via
   574 <function_name>.simps.
   575 
   576 INCOMPATIBILITIES:
   577 
   578   - Theories using datatypes must now have theory Datatype as an
   579     ancestor.
   580   - The specific <typename>.induct_tac no longer exists - use the
   581     generic induct_tac instead.
   582   - natE has been renamed to nat.exhaust - use exhaust_tac
   583     instead of res_inst_tac ... natE. Note that the variable
   584     names in nat.exhaust differ from the names in natE, this
   585     may cause some "fragile" proofs to fail.
   586   - The theorems split_<typename>_case and split_<typename>_case_asm
   587     have been renamed to <typename>.split and <typename>.split_asm.
   588   - Since default sorts of type variables are now handled correctly,
   589     some datatype definitions may have to be annotated with explicit
   590     sort constraints.
   591   - Primrec definitions no longer require function name and type
   592     of recursive argument.
   593 
   594 Consider using isatool fixdatatype to adapt your theories and proof
   595 scripts to the new package (backup your sources first!).
   596 
   597 
   598 * HOL/record package: considerably improved implementation; now
   599 includes concrete syntax for record types, terms, updates; theorems
   600 for surjective pairing and splitting !!-bound record variables; proof
   601 support is as follows:
   602 
   603   1) standard conversions (selectors or updates applied to record
   604 constructor terms) are part of the standard simpset;
   605 
   606   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
   607 made part of standard simpset and claset via addIffs;
   608 
   609   3) a tactic for record field splitting (record_split_tac) is part of
   610 the standard claset (addSWrapper);
   611 
   612 To get a better idea about these rules you may retrieve them via
   613 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
   614 the name of your record type.
   615 
   616 The split tactic 3) conceptually simplifies by the following rule:
   617 
   618   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
   619 
   620 Thus any record variable that is bound by meta-all will automatically
   621 blow up into some record constructor term, consequently the
   622 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
   623 solve record problems automatically.
   624 
   625 
   626 * reorganized the main HOL image: HOL/Integ and String loaded by
   627 default; theory Main includes everything;
   628 
   629 * automatic simplification of integer sums and comparisons, using cancellation;
   630 
   631 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
   632 
   633 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
   634 
   635 * many new identities for unions, intersections, set difference, etc.;
   636 
   637 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
   638 called split_if, split_split, split_sum_case and split_nat_case (to go
   639 with add/delsplits);
   640 
   641 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
   642 (?x::unit) = (); this is made part of the default simpset, which COULD
   643 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
   644 'Delsimprocs [unit_eq_proc];' as last resort); also note that
   645 unit_abs_eta_conv is added in order to counter the effect of
   646 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
   647 %u.f();
   648 
   649 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
   650 makes more sense);
   651 
   652 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   653   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   654   disjointness reasoning but breaking a few old proofs.
   655 
   656 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
   657 to 'converse' from 'inverse' (for compatibility with ZF and some
   658 literature);
   659 
   660 * HOL/recdef can now declare non-recursive functions, with {} supplied as
   661 the well-founded relation;
   662 
   663 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
   664     Compl A.  The "Compl" syntax remains available as input syntax for this
   665     release ONLY.
   666 
   667 * HOL/Update: new theory of function updates:
   668     f(a:=b) == %x. if x=a then b else f x
   669 may also be iterated as in f(a:=b,c:=d,...);
   670 
   671 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
   672 
   673 * HOL/List:
   674   - new function list_update written xs[i:=v] that updates the i-th
   675     list position. May also be iterated as in xs[i:=a,j:=b,...].
   676   - new function `upt' written [i..j(] which generates the list
   677     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
   678     bound write [i..j], which is a shorthand for [i..j+1(].
   679   - new lexicographic orderings and corresponding wellfoundedness theorems.
   680 
   681 * HOL/Arith:
   682   - removed 'pred' (predecessor) function;
   683   - generalized some theorems about n-1;
   684   - many new laws about "div" and "mod";
   685   - new laws about greatest common divisors (see theory ex/Primes);
   686 
   687 * HOL/Relation: renamed the relational operator r^-1 "converse"
   688 instead of "inverse";
   689 
   690 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
   691   of the multiset ordering;
   692 
   693 * directory HOL/Real: a construction of the reals using Dedekind cuts
   694   (not included by default);
   695 
   696 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
   697 
   698 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
   699   programs, i.e. different program variables may have different types.
   700 
   701 * calling (stac rew i) now fails if "rew" has no effect on the goal
   702   [previously, this check worked only if the rewrite rule was unconditional]
   703   Now rew can involve either definitions or equalities (either == or =).
   704 
   705 
   706 *** ZF ***
   707 
   708 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
   709   only the theorems proved on ZF.ML;
   710 
   711 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   712   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   713   disjointness reasoning but breaking a few old proofs.
   714 
   715 * ZF/Update: new theory of function updates
   716     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
   717   may also be iterated as in f(a:=b,c:=d,...);
   718 
   719 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
   720 
   721 * calling (stac rew i) now fails if "rew" has no effect on the goal
   722   [previously, this check worked only if the rewrite rule was unconditional]
   723   Now rew can involve either definitions or equalities (either == or =).
   724 
   725 * case_tac provided for compatibility with HOL
   726     (like the old excluded_middle_tac, but with subgoals swapped)
   727 
   728 
   729 *** Internal programming interfaces ***
   730 
   731 * Pure: several new basic modules made available for general use, see
   732 also src/Pure/README;
   733 
   734 * improved the theory data mechanism to support encapsulation (data
   735 kind name replaced by private Object.kind, acting as authorization
   736 key); new type-safe user interface via functor TheoryDataFun; generic
   737 print_data function becomes basically useless;
   738 
   739 * removed global_names compatibility flag -- all theory declarations
   740 are qualified by default;
   741 
   742 * module Pure/Syntax now offers quote / antiquote translation
   743 functions (useful for Hoare logic etc. with implicit dependencies);
   744 see HOL/ex/Antiquote for an example use;
   745 
   746 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
   747 cterm -> thm;
   748 
   749 * new tactical CHANGED_GOAL for checking that a tactic modifies a
   750 subgoal;
   751 
   752 * Display.print_goals function moved to Locale.print_goals;
   753 
   754 * standard print function for goals supports current_goals_markers
   755 variable for marking begin of proof, end of proof, start of goal; the
   756 default is ("", "", ""); setting current_goals_markers := ("<proof>",
   757 "</proof>", "<goal>") causes SGML like tagged proof state printing,
   758 for example;
   759 
   760 
   761 
   762 New in Isabelle98 (January 1998)
   763 --------------------------------
   764 
   765 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   766 
   767 * changed lexical syntax of terms / types: dots made part of long
   768 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
   769 
   770 * simpset (and claset) reference variable replaced by functions
   771 simpset / simpset_ref;
   772 
   773 * no longer supports theory aliases (via merge) and non-trivial
   774 implicit merge of thms' signatures;
   775 
   776 * most internal names of constants changed due to qualified names;
   777 
   778 * changed Pure/Sequence interface (see Pure/seq.ML);
   779 
   780 
   781 *** General Changes ***
   782 
   783 * hierachically structured name spaces (for consts, types, axms, thms
   784 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
   785 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
   786 isatool fixdots ensures space after dots (e.g. "%x. x"); set
   787 long_names for fully qualified output names; NOTE: ML programs
   788 (special tactics, packages etc.) referring to internal names may have
   789 to be adapted to cope with fully qualified names; in case of severe
   790 backward campatibility problems try setting 'global_names' at compile
   791 time to have enrything declared within a flat name space; one may also
   792 fine tune name declarations in theories via the 'global' and 'local'
   793 section;
   794 
   795 * reimplemented the implicit simpset and claset using the new anytype
   796 data filed in signatures; references simpset:simpset ref etc. are
   797 replaced by functions simpset:unit->simpset and
   798 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
   799 to patch your ML files accordingly;
   800 
   801 * HTML output now includes theory graph data for display with Java
   802 applet or isatool browser; data generated automatically via isatool
   803 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
   804 
   805 * defs may now be conditional; improved rewrite_goals_tac to handle
   806 conditional equations;
   807 
   808 * defs now admits additional type arguments, using TYPE('a) syntax;
   809 
   810 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
   811 creates a new theory node; implicit merge of thms' signatures is
   812 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
   813 transfer:theory->thm->thm in (rare) cases;
   814 
   815 * improved handling of draft signatures / theories; draft thms (and
   816 ctyps, cterms) are automatically promoted to real ones;
   817 
   818 * slightly changed interfaces for oracles: admit many per theory, named
   819 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
   820 
   821 * print_goals: optional output of const types (set show_consts and
   822 show_types);
   823 
   824 * improved output of warnings (###) and errors (***);
   825 
   826 * subgoal_tac displays a warning if the new subgoal has type variables;
   827 
   828 * removed old README and Makefiles;
   829 
   830 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
   831 
   832 * removed obsolete init_pps and init_database;
   833 
   834 * deleted the obsolete tactical STATE, which was declared by
   835     fun STATE tacfun st = tacfun st st;
   836 
   837 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
   838 (which abbreviates $HOME);
   839 
   840 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
   841 use isatool fixseq to adapt your ML programs (this works for fully
   842 qualified references to the Sequence structure only!);
   843 
   844 * use_thy no longer requires writable current directory; it always
   845 reloads .ML *and* .thy file, if either one is out of date;
   846 
   847 
   848 *** Classical Reasoner ***
   849 
   850 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
   851 tactics that use classical reasoning to simplify a subgoal without
   852 splitting it into several subgoals;
   853 
   854 * Safe_tac: like safe_tac but uses the default claset;
   855 
   856 
   857 *** Simplifier ***
   858 
   859 * added simplification meta rules:
   860     (asm_)(full_)simplify: simpset -> thm -> thm;
   861 
   862 * simplifier.ML no longer part of Pure -- has to be loaded by object
   863 logics (again);
   864 
   865 * added prems argument to simplification procedures;
   866 
   867 * HOL, FOL, ZF: added infix function `addsplits':
   868   instead of `<simpset> setloop (split_tac <thms>)'
   869   you can simply write `<simpset> addsplits <thms>'
   870 
   871 
   872 *** Syntax ***
   873 
   874 * TYPE('a) syntax for type reflection terms;
   875 
   876 * no longer handles consts with name "" -- declare as 'syntax' instead;
   877 
   878 * pretty printer: changed order of mixfix annotation preference (again!);
   879 
   880 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
   881 
   882 
   883 *** HOL ***
   884 
   885 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
   886   with `addloop' of the simplifier to faciliate case splitting in premises.
   887 
   888 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
   889 
   890 * HOL/Auth: new protocol proofs including some for the Internet
   891   protocol TLS;
   892 
   893 * HOL/Map: new theory of `maps' a la VDM;
   894 
   895 * HOL/simplifier: simplification procedures nat_cancel_sums for
   896 cancelling out common nat summands from =, <, <= (in)equalities, or
   897 differences; simplification procedures nat_cancel_factor for
   898 cancelling common factor from =, <, <= (in)equalities over natural
   899 sums; nat_cancel contains both kinds of procedures, it is installed by
   900 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
   901 
   902 * HOL/simplifier: terms of the form
   903   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
   904   are rewritten to
   905   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
   906   and those of the form
   907   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
   908   are rewritten to
   909   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
   910 
   911 * HOL/datatype
   912   Each datatype `t' now comes with a theorem `split_t_case' of the form
   913 
   914   P(t_case f1 ... fn x) =
   915      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
   916         ...
   917        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
   918      )
   919 
   920   and a theorem `split_t_case_asm' of the form
   921 
   922   P(t_case f1 ... fn x) =
   923     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
   924         ...
   925        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
   926      )
   927   which can be added to a simpset via `addsplits'. The existing theorems
   928   expand_list_case and expand_option_case have been renamed to
   929   split_list_case and split_option_case.
   930 
   931 * HOL/Arithmetic:
   932   - `pred n' is automatically converted to `n-1'.
   933     Users are strongly encouraged not to use `pred' any longer,
   934     because it will disappear altogether at some point.
   935   - Users are strongly encouraged to write "0 < n" rather than
   936     "n ~= 0". Theorems and proof tools have been modified towards this
   937     `standard'.
   938 
   939 * HOL/Lists:
   940   the function "set_of_list" has been renamed "set" (and its theorems too);
   941   the function "nth" now takes its arguments in the reverse order and
   942   has acquired the infix notation "!" as in "xs!n".
   943 
   944 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
   945 
   946 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
   947   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
   948 
   949 * HOL/record: extensible records with schematic structural subtyping
   950 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
   951 still lacks various theorems and concrete record syntax;
   952 
   953 
   954 *** HOLCF ***
   955 
   956 * removed "axioms" and "generated by" sections;
   957 
   958 * replaced "ops" section by extended "consts" section, which is capable of
   959   handling the continuous function space "->" directly;
   960 
   961 * domain package:
   962   . proves theorems immediately and stores them in the theory,
   963   . creates hierachical name space,
   964   . now uses normal mixfix annotations (instead of cinfix...),
   965   . minor changes to some names and values (for consistency),
   966   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
   967   . separator between mutual domain defs: changed "," to "and",
   968   . improved handling of sort constraints;  now they have to
   969     appear on the left-hand side of the equations only;
   970 
   971 * fixed LAM <x,y,zs>.b syntax;
   972 
   973 * added extended adm_tac to simplifier in HOLCF -- can now discharge
   974 adm (%x. P (t x)), where P is chainfinite and t continuous;
   975 
   976 
   977 *** FOL and ZF ***
   978 
   979 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
   980   with `addloop' of the simplifier to faciliate case splitting in premises.
   981 
   982 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
   983 in HOL, they strip ALL and --> from proved theorems;
   984 
   985 
   986 
   987 New in Isabelle94-8 (May 1997)
   988 ------------------------------
   989 
   990 *** General Changes ***
   991 
   992 * new utilities to build / run / maintain Isabelle etc. (in parts
   993 still somewhat experimental); old Makefiles etc. still functional;
   994 
   995 * new 'Isabelle System Manual';
   996 
   997 * INSTALL text, together with ./configure and ./build scripts;
   998 
   999 * reimplemented type inference for greater efficiency, better error
  1000 messages and clean internal interface;
  1001 
  1002 * prlim command for dealing with lots of subgoals (an easier way of
  1003 setting goals_limit);
  1004 
  1005 
  1006 *** Syntax ***
  1007 
  1008 * supports alternative (named) syntax tables (parser and pretty
  1009 printer); internal interface is provided by add_modesyntax(_i);
  1010 
  1011 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  1012 be used in conjunction with the Isabelle symbol font; uses the
  1013 "symbols" syntax table;
  1014 
  1015 * added token_translation interface (may translate name tokens in
  1016 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  1017 the current print_mode); IMPORTANT: user print translation functions
  1018 are responsible for marking newly introduced bounds
  1019 (Syntax.mark_boundT);
  1020 
  1021 * token translations for modes "xterm" and "xterm_color" that display
  1022 names in bold, underline etc. or colors (which requires a color
  1023 version of xterm);
  1024 
  1025 * infixes may now be declared with names independent of their syntax;
  1026 
  1027 * added typed_print_translation (like print_translation, but may
  1028 access type of constant);
  1029 
  1030 
  1031 *** Classical Reasoner ***
  1032 
  1033 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  1034 some limitations.  Blast_tac...
  1035   + ignores addss, addbefore, addafter; this restriction is intrinsic
  1036   + ignores elimination rules that don't have the correct format
  1037         (the conclusion MUST be a formula variable)
  1038   + ignores types, which can make HOL proofs fail
  1039   + rules must not require higher-order unification, e.g. apply_type in ZF
  1040     [message "Function Var's argument not a bound variable" relates to this]
  1041   + its proof strategy is more general but can actually be slower
  1042 
  1043 * substitution with equality assumptions no longer permutes other
  1044 assumptions;
  1045 
  1046 * minor changes in semantics of addafter (now called addaltern); renamed
  1047 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  1048 (and access functions for it);
  1049 
  1050 * improved combination of classical reasoner and simplifier:
  1051   + functions for handling clasimpsets
  1052   + improvement of addss: now the simplifier is called _after_ the
  1053     safe steps.
  1054   + safe variant of addss called addSss: uses safe simplifications
  1055     _during_ the safe steps. It is more complete as it allows multiple
  1056     instantiations of unknowns (e.g. with slow_tac).
  1057 
  1058 *** Simplifier ***
  1059 
  1060 * added interface for simplification procedures (functions that
  1061 produce *proven* rewrite rules on the fly, depending on current
  1062 redex);
  1063 
  1064 * ordering on terms as parameter (used for ordered rewriting);
  1065 
  1066 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  1067 
  1068 * the solver is now split into a safe and an unsafe part.
  1069 This should be invisible for the normal user, except that the
  1070 functions setsolver and addsolver have been renamed to setSolver and
  1071 addSolver; added safe_asm_full_simp_tac;
  1072 
  1073 
  1074 *** HOL ***
  1075 
  1076 * a generic induction tactic `induct_tac' which works for all datatypes and
  1077 also for type `nat';
  1078 
  1079 * a generic case distinction tactic `exhaust_tac' which works for all
  1080 datatypes and also for type `nat';
  1081 
  1082 * each datatype comes with a function `size';
  1083 
  1084 * patterns in case expressions allow tuple patterns as arguments to
  1085 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  1086 
  1087 * primrec now also works with type nat;
  1088 
  1089 * recdef: a new declaration form, allows general recursive functions to be
  1090 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  1091 
  1092 * the constant for negation has been renamed from "not" to "Not" to
  1093 harmonize with FOL, ZF, LK, etc.;
  1094 
  1095 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  1096 infinite lists;
  1097 
  1098 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  1099 
  1100 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  1101 problems in commutative rings, using axiomatic type classes for + and *;
  1102 
  1103 * more examples in HOL/MiniML and HOL/Auth;
  1104 
  1105 * more default rewrite rules for quantifiers, union/intersection;
  1106 
  1107 * a new constant `arbitrary == @x.False';
  1108 
  1109 * HOLCF/IOA replaces old HOL/IOA;
  1110 
  1111 * HOLCF changes: derived all rules and arities
  1112   + axiomatic type classes instead of classes
  1113   + typedef instead of faking type definitions
  1114   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  1115   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  1116   + eliminated the types void, one, tr
  1117   + use unit lift and bool lift (with translations) instead of one and tr
  1118   + eliminated blift from Lift3.thy (use Def instead of blift)
  1119   all eliminated rules are derived as theorems --> no visible changes ;
  1120 
  1121 
  1122 *** ZF ***
  1123 
  1124 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  1125 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  1126 as ZF_cs addSIs [equalityI];
  1127 
  1128 
  1129 
  1130 New in Isabelle94-7 (November 96)
  1131 ---------------------------------
  1132 
  1133 * allowing negative levels (as offsets) in prlev and choplev;
  1134 
  1135 * super-linear speedup for large simplifications;
  1136 
  1137 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  1138 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  1139 FAIL); can suppress it using the command Delsimps (ex_simps @
  1140 all_simps); De Morgan laws are also now included, by default;
  1141 
  1142 * improved printing of ==>  :  ~:
  1143 
  1144 * new object-logic "Sequents" adds linear logic, while replacing LK
  1145 and Modal (thanks to Sara Kalvala);
  1146 
  1147 * HOL/Auth: correctness proofs for authentication protocols;
  1148 
  1149 * HOL: new auto_tac combines rewriting and classical reasoning (many
  1150 examples on HOL/Auth);
  1151 
  1152 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  1153 the rewriter and classical reasoner simultaneously;
  1154 
  1155 * function uresult no longer returns theorems in "standard" format;
  1156 regain previous version by: val uresult = standard o uresult;
  1157 
  1158 
  1159 
  1160 New in Isabelle94-6
  1161 -------------------
  1162 
  1163 * oracles -- these establish an interface between Isabelle and trusted
  1164 external reasoners, which may deliver results as theorems;
  1165 
  1166 * proof objects (in particular record all uses of oracles);
  1167 
  1168 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  1169 
  1170 * "constdefs" section in theory files;
  1171 
  1172 * "primrec" section (HOL) no longer requires names;
  1173 
  1174 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  1175 
  1176 
  1177 
  1178 New in Isabelle94-5
  1179 -------------------
  1180 
  1181 * reduced space requirements;
  1182 
  1183 * automatic HTML generation from theories;
  1184 
  1185 * theory files no longer require "..." (quotes) around most types;
  1186 
  1187 * new examples, including two proofs of the Church-Rosser theorem;
  1188 
  1189 * non-curried (1994) version of HOL is no longer distributed;
  1190 
  1191 
  1192 
  1193 New in Isabelle94-4
  1194 -------------------
  1195 
  1196 * greatly reduced space requirements;
  1197 
  1198 * theory files (.thy) no longer require \...\ escapes at line breaks;
  1199 
  1200 * searchable theorem database (see the section "Retrieving theorems" on
  1201 page 8 of the Reference Manual);
  1202 
  1203 * new examples, including Grabczewski's monumental case study of the
  1204 Axiom of Choice;
  1205 
  1206 * The previous version of HOL renamed to Old_HOL;
  1207 
  1208 * The new version of HOL (previously called CHOL) uses a curried syntax
  1209 for functions.  Application looks like f a b instead of f(a,b);
  1210 
  1211 * Mutually recursive inductive definitions finally work in HOL;
  1212 
  1213 * In ZF, pattern-matching on tuples is now available in all abstractions and
  1214 translates to the operator "split";
  1215 
  1216 
  1217 
  1218 New in Isabelle94-3
  1219 -------------------
  1220 
  1221 * new infix operator, addss, allowing the classical reasoner to
  1222 perform simplification at each step of its search.  Example:
  1223         fast_tac (cs addss ss)
  1224 
  1225 * a new logic, CHOL, the same as HOL, but with a curried syntax
  1226 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  1227 look like (a,b) instead of <a,b>;
  1228 
  1229 * PLEASE NOTE: CHOL will eventually replace HOL!
  1230 
  1231 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  1232 It translates to the operator "split".  A new theory of integers is available;
  1233 
  1234 * In ZF, integer numerals now denote two's-complement binary integers.
  1235 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  1236 
  1237 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  1238 of the Axiom of Choice;
  1239 
  1240 
  1241 
  1242 New in Isabelle94-2
  1243 -------------------
  1244 
  1245 * Significantly faster resolution;
  1246 
  1247 * the different sections in a .thy file can now be mixed and repeated
  1248 freely;
  1249 
  1250 * Database of theorems for FOL, HOL and ZF.  New
  1251 commands including qed, qed_goal and bind_thm store theorems in the database.
  1252 
  1253 * Simple database queries: return a named theorem (get_thm) or all theorems of
  1254 a given theory (thms_of), or find out what theory a theorem was proved in
  1255 (theory_of_thm);
  1256 
  1257 * Bugs fixed in the inductive definition and datatype packages;
  1258 
  1259 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  1260 and HOL_dup_cs obsolete;
  1261 
  1262 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  1263 have been removed;
  1264 
  1265 * Simpler definition of function space in ZF;
  1266 
  1267 * new results about cardinal and ordinal arithmetic in ZF;
  1268 
  1269 * 'subtype' facility in HOL for introducing new types as subsets of existing
  1270 types;
  1271 
  1272 
  1273 $Id$