NEWS
author wenzelm
Wed Apr 05 21:06:06 2000 +0200 (2000-04-05)
changeset 8673 987ea1a559d0
parent 8655 16906e600c9a
child 8705 a3da5538d924
permissions -rw-r--r--
Isar: simplified (more robust) goal selection of proof methods;
Isar: tuned 'let' syntax: replace 'as' keyword by 'and';
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** Overview of INCOMPATIBILITIES (see below for more details) ***
     8 
     9 * HOL: the constant for f``x is now "image" rather than "op ``".
    10 
    11 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
    12 
    13 * HOL: simplification no longer dives into case-expressions
    14 
    15 * HOL: the recursion equations generated by 'recdef' are now called
    16 f.simps instead of f.rules;
    17 
    18 * ML: PureThy.add_thms/add_axioms/add_defs return theorems as well;
    19 
    20 
    21 *** Document preparation ***
    22 
    23 * isatool mkdir provides easy setup of Isabelle session directories,
    24 including proper document sources;
    25 
    26 * generated LaTeX sources are now deleted after successful run
    27 (isatool document -c); may retain a copy somewhere else via -D option
    28 of isatool usedir;
    29 
    30 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
    31 style files, achieving self-contained LaTeX sources;
    32 
    33 * old-style theories now produce (crude) LaTeX output as well;
    34 
    35 
    36 *** Isar ***
    37 
    38 * Pure: local results and corresponding term bindings are now subject
    39 to Hindley-Milner polymorphism (similar to ML); this accommodates
    40 incremental type-inference nicely;
    41 
    42 * Pure: new 'obtain' language element supports generalized existence
    43 reasoning;
    44 
    45 * Pure: new calculational elements 'moreover' and 'ultimately' support
    46 plain accumulation of results, without applying any rules yet;
    47 
    48 * Pure: scalable support for case-analysis type proofs: new 'case'
    49 language element refers to local contexts symbolically, as produced by
    50 certain proof methods; internally, case names are attached to theorems
    51 as "tags";
    52 
    53 * Pure now provides its own version of intro/elim/dest attributes;
    54 useful for building new logics, but beware of confusion with the
    55 Provers/classical ones;
    56 
    57 * Provers: splitter support (via 'split' attribute and 'simp' method
    58 modifier); 'simp' method: 'only:' modifier removes loopers as well
    59 (including splits);
    60 
    61 * HOL: new proof method 'cases' and improved version of 'induct' now
    62 support named cases; major packages (inductive, datatype, primrec,
    63 recdef) support case names and properly name parameters;
    64 
    65 * HOL: removed 'case_split' thm binding, should use 'cases' proof
    66 method anyway;
    67 
    68 * names of theorems etc. may be natural numbers as well;
    69 
    70 * Provers: intro/elim/dest attributes: changed ! / !! flags to ? / ??;
    71 
    72 * 'pr' command: optional goals_limit argument;
    73 
    74 * diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
    75 additional print modes to be specified; e.g. "pr(latex)" will print
    76 proof state according to the Isabelle LaTeX style;
    77 
    78 * improved support for emulating tactic scripts, including proof
    79 methods 'tactic', 'res_inst_tac' etc., 'subgoal_tac', and 'case_tac' /
    80 'induct_tac' (for HOL datatypes);
    81 
    82 * simplified (more robust) goal selection of proof methods: 1st goal,
    83 all goals, or explicit goal specifier (tactic emulation); thus 'proof
    84 method scripts' have to be in depth-first order;
    85 
    86 * tuned 'let' syntax: replace 'as' keyword by 'and';
    87 
    88 
    89 *** HOL ***
    90 
    91 * HOL/Algebra: new theory of rings and univariate polynomials, by
    92 Clemens Ballarin;
    93 
    94 * HOL/record: fixed select-update simplification procedure to handle
    95 extended records as well; admit "r" as field name;
    96 
    97 * HOL/ex: new theory Factorization proving the Fundamental Theorem of
    98 Arithmetic, by Thomas M Rasmussen;
    99 
   100 * HOL/ex/Multiquote: multiple nested quotations and anti-quotations --
   101 basically a generalized version of de-Bruijn representation; very
   102 useful in avoiding lifting all operations;
   103 
   104 * new version of "case_tac" subsumes both boolean case split and
   105 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
   106 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
   107 
   108 * simplification no longer dives into case-expressions: only the selector
   109 expression is simplified, but not the remaining arms. To enable full
   110 simplification of case-expressions for datatype t, you need to remove
   111 t.weak_case_cong from the simpset, either permanently
   112 (Delcongs[thm"t.weak_case_cong"];) or locally (delcongs [...]).
   113 
   114 * the recursion equations generated by 'recdef' for function 'f' are
   115 now called f.simps instead of f.rules; if all termination conditions
   116 are proved automatically, these simplification rules are added to the
   117 simpset, as in primrec; rules may be named individually as well,
   118 resulting in a separate list of theorems for each equation;
   119 
   120 
   121 *** General ***
   122 
   123 * compression of ML heaps images may now be controlled via -c option
   124 of isabelle and isatool usedir (currently only observed by Poly/ML);
   125 
   126 * ML: new combinators |>> and |>>> for incremental transformations
   127 with secondary results (e.g. certain theory extensions):
   128 
   129 
   130 
   131 New in Isabelle99 (October 1999)
   132 --------------------------------
   133 
   134 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   135 
   136 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
   137 are no longer simplified.  (This allows the simplifier to unfold recursive
   138 functional programs.)  To restore the old behaviour, declare
   139 
   140     Delcongs [if_weak_cong];
   141 
   142 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
   143 complement;
   144 
   145 * HOL: the predicate "inj" is now defined by translation to "inj_on";
   146 
   147 * HOL/datatype: mutual_induct_tac no longer exists --
   148   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
   149 
   150 * HOL/typedef: fixed type inference for representing set; type
   151 arguments now have to occur explicitly on the rhs as type constraints;
   152 
   153 * ZF: The con_defs part of an inductive definition may no longer refer
   154 to constants declared in the same theory;
   155 
   156 * HOL, ZF: the function mk_cases, generated by the inductive
   157 definition package, has lost an argument.  To simplify its result, it
   158 uses the default simpset instead of a supplied list of theorems.
   159 
   160 * HOL/List: the constructors of type list are now Nil and Cons;
   161 
   162 * Simplifier: the type of the infix ML functions
   163 	setSSolver addSSolver setSolver addSolver
   164 is now  simpset * solver -> simpset  where `solver' is a new abstract type
   165 for packaging solvers. A solver is created via
   166 	mk_solver: string -> (thm list -> int -> tactic) -> solver
   167 where the string argument is only a comment.
   168 
   169 
   170 *** Proof tools ***
   171 
   172 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
   173 decision procedure for linear arithmetic. Currently it is used for
   174 types `nat', `int', and `real' in HOL (see below); it can, should and
   175 will be instantiated for other types and logics as well.
   176 
   177 * The simplifier now accepts rewrite rules with flexible heads, eg
   178      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
   179   They are applied like any rule with a non-pattern lhs, i.e. by first-order
   180   matching.
   181 
   182 
   183 *** General ***
   184 
   185 * New Isabelle/Isar subsystem provides an alternative to traditional
   186 tactical theorem proving; together with the ProofGeneral/isar user
   187 interface it offers an interactive environment for developing human
   188 readable proof documents (Isar == Intelligible semi-automated
   189 reasoning); for further information see isatool doc isar-ref,
   190 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
   191 
   192 * improved presentation of theories: better HTML markup (including
   193 colors), graph views in several sizes; isatool usedir now provides a
   194 proper interface for user theories (via -P option); actual document
   195 preparation based on (PDF)LaTeX is available as well (for new-style
   196 theories only); see isatool doc system for more information;
   197 
   198 * native support for Proof General, both for classic Isabelle and
   199 Isabelle/Isar;
   200 
   201 * ML function thm_deps visualizes dependencies of theorems and lemmas,
   202 using the graph browser tool;
   203 
   204 * Isabelle manuals now also available as PDF;
   205 
   206 * theory loader rewritten from scratch (may not be fully
   207 bug-compatible); old loadpath variable has been replaced by show_path,
   208 add_path, del_path, reset_path functions; new operations such as
   209 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
   210 isatool doc ref);
   211 
   212 * improved isatool install: option -k creates KDE application icon,
   213 option -p DIR installs standalone binaries;
   214 
   215 * added ML_PLATFORM setting (useful for cross-platform installations);
   216 more robust handling of platform specific ML images for SML/NJ;
   217 
   218 * the settings environment is now statically scoped, i.e. it is never
   219 created again in sub-processes invoked from isabelle, isatool, or
   220 Isabelle;
   221 
   222 * path element specification '~~' refers to '$ISABELLE_HOME';
   223 
   224 * in locales, the "assumes" and "defines" parts may be omitted if
   225 empty;
   226 
   227 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
   228 long arrows);
   229 
   230 * new print_mode "HTML";
   231 
   232 * new flag show_tags controls display of tags of theorems (which are
   233 basically just comments that may be attached by some tools);
   234 
   235 * Isamode 2.6 requires patch to accomodate change of Isabelle font
   236 mode and goal output format:
   237 
   238 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
   239 244c244
   240 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
   241 ---
   242 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
   243 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
   244 181c181
   245 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
   246 ---
   247 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
   248 
   249 * function bind_thms stores lists of theorems (cf. bind_thm);
   250 
   251 * new shorthand tactics ftac, eatac, datac, fatac;
   252 
   253 * qed (and friends) now accept "" as result name; in that case the
   254 theorem is not stored, but proper checks and presentation of the
   255 result still apply;
   256 
   257 * theorem database now also indexes constants "Trueprop", "all",
   258 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
   259 
   260 
   261 *** HOL ***
   262 
   263 ** HOL arithmetic **
   264 
   265 * There are now decision procedures for linear arithmetic over nat and
   266 int:
   267 
   268 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
   269 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
   270 are treated as atomic; subformulae not involving type `nat' or `int'
   271 are ignored; quantified subformulae are ignored unless they are
   272 positive universal or negative existential. The tactic has to be
   273 invoked by hand and can be a little bit slow. In particular, the
   274 running time is exponential in the number of occurrences of `min' and
   275 `max', and `-' on `nat'.
   276 
   277 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
   278 (negated) (in)equalities among the premises and the conclusion into
   279 account (i.e. no compound formulae) and does not know about `min' and
   280 `max', and `-' on `nat'. It is fast and is used automatically by the
   281 simplifier.
   282 
   283 NB: At the moment, these decision procedures do not cope with mixed
   284 nat/int formulae where the two parts interact, such as `m < n ==>
   285 int(m) < int(n)'.
   286 
   287 * HOL/Numeral provides a generic theory of numerals (encoded
   288 efficiently as bit strings); setup for types nat/int/real is in place;
   289 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
   290 int, existing theories and proof scripts may require a few additional
   291 type constraints;
   292 
   293 * integer division and remainder can now be performed on constant
   294 arguments;
   295 
   296 * many properties of integer multiplication, division and remainder
   297 are now available;
   298 
   299 * An interface to the Stanford Validity Checker (SVC) is available through the
   300 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
   301 are proved automatically.  SVC must be installed separately, and its results
   302 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
   303 invocation of the underlying oracle).  For SVC see
   304   http://verify.stanford.edu/SVC
   305 
   306 * IsaMakefile: the HOL-Real target now builds an actual image;
   307 
   308 
   309 ** HOL misc **
   310 
   311 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
   312 (in Isabelle/Isar) -- by Gertrud Bauer;
   313 
   314 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
   315 analysis for assembly languages with subtypes;
   316 
   317 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
   318 -- avoids syntactic ambiguities and treats state, transition, and
   319 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
   320 changed syntax and (many) tactics;
   321 
   322 * HOL/inductive: Now also handles more general introduction rules such
   323   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
   324   theorems are now maintained within the theory (maintained via the
   325   "mono" attribute);
   326 
   327 * HOL/datatype: Now also handles arbitrarily branching datatypes
   328   (using function types) such as
   329 
   330   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
   331 
   332 * HOL/record: record_simproc (part of the default simpset) takes care
   333 of selectors applied to updated records; record_split_tac is no longer
   334 part of the default claset; update_defs may now be removed from the
   335 simpset in many cases; COMPATIBILITY: old behavior achieved by
   336 
   337   claset_ref () := claset() addSWrapper record_split_wrapper;
   338   Delsimprocs [record_simproc]
   339 
   340 * HOL/typedef: fixed type inference for representing set; type
   341 arguments now have to occur explicitly on the rhs as type constraints;
   342 
   343 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
   344 names rather than an ML expression;
   345 
   346 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
   347 supplied later.  Program schemes can be defined, such as
   348     "While B C s = (if B s then While B C (C s) else s)"
   349 where the well-founded relation can be chosen after B and C have been given.
   350 
   351 * HOL/List: the constructors of type list are now Nil and Cons;
   352 INCOMPATIBILITY: while [] and infix # syntax is still there, of
   353 course, ML tools referring to List.list.op # etc. have to be adapted;
   354 
   355 * HOL_quantifiers flag superseded by "HOL" print mode, which is
   356 disabled by default; run isabelle with option -m HOL to get back to
   357 the original Gordon/HOL-style output;
   358 
   359 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
   360 ALL x<=y. P, EX x<y. P, EX x<=y. P;
   361 
   362 * HOL basic syntax simplified (more orthogonal): all variants of
   363 All/Ex now support plain / symbolic / HOL notation; plain syntax for
   364 Eps operator is provided as well: "SOME x. P[x]";
   365 
   366 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
   367 
   368 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
   369 thus available for user theories;
   370 
   371 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
   372 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
   373 time;
   374 
   375 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
   376 several times and then mp;
   377 
   378 
   379 *** LK ***
   380 
   381 * the notation <<...>> is now available as a notation for sequences of
   382 formulas;
   383 
   384 * the simplifier is now installed
   385 
   386 * the axiom system has been generalized (thanks to Soren Heilmann) 
   387 
   388 * the classical reasoner now has a default rule database
   389 
   390 
   391 *** ZF ***
   392 
   393 * new primrec section allows primitive recursive functions to be given
   394 directly (as in HOL) over datatypes and the natural numbers;
   395 
   396 * new tactics induct_tac and exhaust_tac for induction (or case
   397 analysis) over datatypes and the natural numbers;
   398 
   399 * the datatype declaration of type T now defines the recursor T_rec;
   400 
   401 * simplification automatically does freeness reasoning for datatype
   402 constructors;
   403 
   404 * automatic type-inference, with AddTCs command to insert new
   405 type-checking rules;
   406 
   407 * datatype introduction rules are now added as Safe Introduction rules
   408 to the claset;
   409 
   410 * the syntax "if P then x else y" is now available in addition to
   411 if(P,x,y);
   412 
   413 
   414 *** Internal programming interfaces ***
   415 
   416 * tuned simplifier trace output; new flag debug_simp;
   417 
   418 * structures Vartab / Termtab (instances of TableFun) offer efficient
   419 tables indexed by indexname_ord / term_ord (compatible with aconv);
   420 
   421 * AxClass.axclass_tac lost the theory argument;
   422 
   423 * tuned current_goals_markers semantics: begin / end goal avoids
   424 printing empty lines;
   425 
   426 * removed prs and prs_fn hook, which was broken because it did not
   427 include \n in its semantics, forcing writeln to add one
   428 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
   429 string -> unit if you really want to output text without newline;
   430 
   431 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
   432 plain output, interface builders may have to enable 'isabelle_font'
   433 mode to get Isabelle font glyphs as before;
   434 
   435 * refined token_translation interface; INCOMPATIBILITY: output length
   436 now of type real instead of int;
   437 
   438 * theory loader actions may be traced via new ThyInfo.add_hook
   439 interface (see src/Pure/Thy/thy_info.ML); example application: keep
   440 your own database of information attached to *whole* theories -- as
   441 opposed to intra-theory data slots offered via TheoryDataFun;
   442 
   443 * proper handling of dangling sort hypotheses (at last!);
   444 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
   445 extra sort hypotheses that can be witnessed from the type signature;
   446 the force_strip_shyps flag is gone, any remaining shyps are simply
   447 left in the theorem (with a warning issued by strip_shyps_warning);
   448 
   449 
   450 
   451 New in Isabelle98-1 (October 1998)
   452 ----------------------------------
   453 
   454 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   455 
   456 * several changes of automated proof tools;
   457 
   458 * HOL: major changes to the inductive and datatype packages, including
   459 some minor incompatibilities of theory syntax;
   460 
   461 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
   462 called `inj_on';
   463 
   464 * HOL: removed duplicate thms in Arith:
   465   less_imp_add_less  should be replaced by  trans_less_add1
   466   le_imp_add_le      should be replaced by  trans_le_add1
   467 
   468 * HOL: unary minus is now overloaded (new type constraints may be
   469 required);
   470 
   471 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
   472 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
   473 now taken as an integer constant.
   474 
   475 * Pure: ML function 'theory_of' renamed to 'theory';
   476 
   477 
   478 *** Proof tools ***
   479 
   480 * Simplifier:
   481   1. Asm_full_simp_tac is now more aggressive.
   482      1. It will sometimes reorient premises if that increases their power to
   483         simplify.
   484      2. It does no longer proceed strictly from left to right but may also
   485         rotate premises to achieve further simplification.
   486      For compatibility reasons there is now Asm_lr_simp_tac which is like the
   487      old Asm_full_simp_tac in that it does not rotate premises.
   488   2. The simplifier now knows a little bit about nat-arithmetic.
   489 
   490 * Classical reasoner: wrapper mechanism for the classical reasoner now
   491 allows for selected deletion of wrappers, by introduction of names for
   492 wrapper functionals.  This implies that addbefore, addSbefore,
   493 addaltern, and addSaltern now take a pair (name, tactic) as argument,
   494 and that adding two tactics with the same name overwrites the first
   495 one (emitting a warning).
   496   type wrapper = (int -> tactic) -> (int -> tactic)
   497   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
   498   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
   499   delWrapper, delSWrapper: claset *  string            -> claset
   500   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
   501 
   502 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
   503 semantics; addbefore now affects only the unsafe part of step_tac
   504 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
   505 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
   506 by Force_tac;
   507 
   508 * Classical reasoner: setwrapper to setWrapper and compwrapper to
   509 compWrapper; added safe wrapper (and access functions for it);
   510 
   511 * HOL/split_all_tac is now much faster and fails if there is nothing
   512 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
   513 and the names of the automatically generated variables have changed.
   514 split_all_tac has moved within claset() from unsafe wrappers to safe
   515 wrappers, which means that !!-bound variables are split much more
   516 aggressively, and safe_tac and clarify_tac now split such variables.
   517 If this splitting is not appropriate, use delSWrapper "split_all_tac".
   518 Note: the same holds for record_split_tac, which does the job of
   519 split_all_tac for record fields.
   520 
   521 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
   522 permanently to the default simpset using Addsplits just like
   523 Addsimps. They can be removed via Delsplits just like
   524 Delsimps. Lower-case versions are also available.
   525 
   526 * HOL/Simplifier: The rule split_if is now part of the default
   527 simpset. This means that the simplifier will eliminate all occurrences
   528 of if-then-else in the conclusion of a goal. To prevent this, you can
   529 either remove split_if completely from the default simpset by
   530 `Delsplits [split_if]' or remove it in a specific call of the
   531 simplifier using `... delsplits [split_if]'.  You can also add/delete
   532 other case splitting rules to/from the default simpset: every datatype
   533 generates suitable rules `split_t_case' and `split_t_case_asm' (where
   534 t is the name of the datatype).
   535 
   536 * Classical reasoner / Simplifier combination: new force_tac (and
   537 derivatives Force_tac, force) combines rewriting and classical
   538 reasoning (and whatever other tools) similarly to auto_tac, but is
   539 aimed to solve the given subgoal completely.
   540 
   541 
   542 *** General ***
   543 
   544 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
   545 and `goalw': the theory is no longer needed as an explicit argument -
   546 the current theory context is used; assumptions are no longer returned
   547 at the ML-level unless one of them starts with ==> or !!; it is
   548 recommended to convert to these new commands using isatool fixgoal
   549 (backup your sources first!);
   550 
   551 * new top-level commands 'thm' and 'thms' for retrieving theorems from
   552 the current theory context, and 'theory' to lookup stored theories;
   553 
   554 * new theory section 'locale' for declaring constants, assumptions and
   555 definitions that have local scope;
   556 
   557 * new theory section 'nonterminals' for purely syntactic types;
   558 
   559 * new theory section 'setup' for generic ML setup functions
   560 (e.g. package initialization);
   561 
   562 * the distribution now includes Isabelle icons: see
   563 lib/logo/isabelle-{small,tiny}.xpm;
   564 
   565 * isatool install - install binaries with absolute references to
   566 ISABELLE_HOME/bin;
   567 
   568 * isatool logo -- create instances of the Isabelle logo (as EPS);
   569 
   570 * print mode 'emacs' reserved for Isamode;
   571 
   572 * support multiple print (ast) translations per constant name;
   573 
   574 * theorems involving oracles are now printed with a suffixed [!];
   575 
   576 
   577 *** HOL ***
   578 
   579 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
   580 
   581 * HOL/inductive package reorganized and improved: now supports mutual
   582 definitions such as
   583 
   584   inductive EVEN ODD
   585     intrs
   586       null "0 : EVEN"
   587       oddI "n : EVEN ==> Suc n : ODD"
   588       evenI "n : ODD ==> Suc n : EVEN"
   589 
   590 new theorem list "elims" contains an elimination rule for each of the
   591 recursive sets; inductive definitions now handle disjunctive premises
   592 correctly (also ZF);
   593 
   594 INCOMPATIBILITIES: requires Inductive as an ancestor; component
   595 "mutual_induct" no longer exists - the induction rule is always
   596 contained in "induct";
   597 
   598 
   599 * HOL/datatype package re-implemented and greatly improved: now
   600 supports mutually recursive datatypes such as
   601 
   602   datatype
   603     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
   604             | SUM ('a aexp) ('a aexp)
   605             | DIFF ('a aexp) ('a aexp)
   606             | NUM 'a
   607   and
   608     'a bexp = LESS ('a aexp) ('a aexp)
   609             | AND ('a bexp) ('a bexp)
   610             | OR ('a bexp) ('a bexp)
   611 
   612 as well as indirectly recursive datatypes such as
   613 
   614   datatype
   615     ('a, 'b) term = Var 'a
   616                   | App 'b ((('a, 'b) term) list)
   617 
   618 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
   619 induction on mutually / indirectly recursive datatypes.
   620 
   621 Primrec equations are now stored in theory and can be accessed via
   622 <function_name>.simps.
   623 
   624 INCOMPATIBILITIES:
   625 
   626   - Theories using datatypes must now have theory Datatype as an
   627     ancestor.
   628   - The specific <typename>.induct_tac no longer exists - use the
   629     generic induct_tac instead.
   630   - natE has been renamed to nat.exhaust - use exhaust_tac
   631     instead of res_inst_tac ... natE. Note that the variable
   632     names in nat.exhaust differ from the names in natE, this
   633     may cause some "fragile" proofs to fail.
   634   - The theorems split_<typename>_case and split_<typename>_case_asm
   635     have been renamed to <typename>.split and <typename>.split_asm.
   636   - Since default sorts of type variables are now handled correctly,
   637     some datatype definitions may have to be annotated with explicit
   638     sort constraints.
   639   - Primrec definitions no longer require function name and type
   640     of recursive argument.
   641 
   642 Consider using isatool fixdatatype to adapt your theories and proof
   643 scripts to the new package (backup your sources first!).
   644 
   645 
   646 * HOL/record package: considerably improved implementation; now
   647 includes concrete syntax for record types, terms, updates; theorems
   648 for surjective pairing and splitting !!-bound record variables; proof
   649 support is as follows:
   650 
   651   1) standard conversions (selectors or updates applied to record
   652 constructor terms) are part of the standard simpset;
   653 
   654   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
   655 made part of standard simpset and claset via addIffs;
   656 
   657   3) a tactic for record field splitting (record_split_tac) is part of
   658 the standard claset (addSWrapper);
   659 
   660 To get a better idea about these rules you may retrieve them via
   661 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
   662 the name of your record type.
   663 
   664 The split tactic 3) conceptually simplifies by the following rule:
   665 
   666   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
   667 
   668 Thus any record variable that is bound by meta-all will automatically
   669 blow up into some record constructor term, consequently the
   670 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
   671 solve record problems automatically.
   672 
   673 
   674 * reorganized the main HOL image: HOL/Integ and String loaded by
   675 default; theory Main includes everything;
   676 
   677 * automatic simplification of integer sums and comparisons, using cancellation;
   678 
   679 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
   680 
   681 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
   682 
   683 * many new identities for unions, intersections, set difference, etc.;
   684 
   685 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
   686 called split_if, split_split, split_sum_case and split_nat_case (to go
   687 with add/delsplits);
   688 
   689 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
   690 (?x::unit) = (); this is made part of the default simpset, which COULD
   691 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
   692 'Delsimprocs [unit_eq_proc];' as last resort); also note that
   693 unit_abs_eta_conv is added in order to counter the effect of
   694 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
   695 %u.f();
   696 
   697 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
   698 makes more sense);
   699 
   700 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   701   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   702   disjointness reasoning but breaking a few old proofs.
   703 
   704 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
   705 to 'converse' from 'inverse' (for compatibility with ZF and some
   706 literature);
   707 
   708 * HOL/recdef can now declare non-recursive functions, with {} supplied as
   709 the well-founded relation;
   710 
   711 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
   712     Compl A.  The "Compl" syntax remains available as input syntax for this
   713     release ONLY.
   714 
   715 * HOL/Update: new theory of function updates:
   716     f(a:=b) == %x. if x=a then b else f x
   717 may also be iterated as in f(a:=b,c:=d,...);
   718 
   719 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
   720 
   721 * HOL/List:
   722   - new function list_update written xs[i:=v] that updates the i-th
   723     list position. May also be iterated as in xs[i:=a,j:=b,...].
   724   - new function `upt' written [i..j(] which generates the list
   725     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
   726     bound write [i..j], which is a shorthand for [i..j+1(].
   727   - new lexicographic orderings and corresponding wellfoundedness theorems.
   728 
   729 * HOL/Arith:
   730   - removed 'pred' (predecessor) function;
   731   - generalized some theorems about n-1;
   732   - many new laws about "div" and "mod";
   733   - new laws about greatest common divisors (see theory ex/Primes);
   734 
   735 * HOL/Relation: renamed the relational operator r^-1 "converse"
   736 instead of "inverse";
   737 
   738 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
   739   of the multiset ordering;
   740 
   741 * directory HOL/Real: a construction of the reals using Dedekind cuts
   742   (not included by default);
   743 
   744 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
   745 
   746 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
   747   programs, i.e. different program variables may have different types.
   748 
   749 * calling (stac rew i) now fails if "rew" has no effect on the goal
   750   [previously, this check worked only if the rewrite rule was unconditional]
   751   Now rew can involve either definitions or equalities (either == or =).
   752 
   753 
   754 *** ZF ***
   755 
   756 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
   757   only the theorems proved on ZF.ML;
   758 
   759 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   760   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   761   disjointness reasoning but breaking a few old proofs.
   762 
   763 * ZF/Update: new theory of function updates
   764     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
   765   may also be iterated as in f(a:=b,c:=d,...);
   766 
   767 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
   768 
   769 * calling (stac rew i) now fails if "rew" has no effect on the goal
   770   [previously, this check worked only if the rewrite rule was unconditional]
   771   Now rew can involve either definitions or equalities (either == or =).
   772 
   773 * case_tac provided for compatibility with HOL
   774     (like the old excluded_middle_tac, but with subgoals swapped)
   775 
   776 
   777 *** Internal programming interfaces ***
   778 
   779 * Pure: several new basic modules made available for general use, see
   780 also src/Pure/README;
   781 
   782 * improved the theory data mechanism to support encapsulation (data
   783 kind name replaced by private Object.kind, acting as authorization
   784 key); new type-safe user interface via functor TheoryDataFun; generic
   785 print_data function becomes basically useless;
   786 
   787 * removed global_names compatibility flag -- all theory declarations
   788 are qualified by default;
   789 
   790 * module Pure/Syntax now offers quote / antiquote translation
   791 functions (useful for Hoare logic etc. with implicit dependencies);
   792 see HOL/ex/Antiquote for an example use;
   793 
   794 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
   795 cterm -> thm;
   796 
   797 * new tactical CHANGED_GOAL for checking that a tactic modifies a
   798 subgoal;
   799 
   800 * Display.print_goals function moved to Locale.print_goals;
   801 
   802 * standard print function for goals supports current_goals_markers
   803 variable for marking begin of proof, end of proof, start of goal; the
   804 default is ("", "", ""); setting current_goals_markers := ("<proof>",
   805 "</proof>", "<goal>") causes SGML like tagged proof state printing,
   806 for example;
   807 
   808 
   809 
   810 New in Isabelle98 (January 1998)
   811 --------------------------------
   812 
   813 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   814 
   815 * changed lexical syntax of terms / types: dots made part of long
   816 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
   817 
   818 * simpset (and claset) reference variable replaced by functions
   819 simpset / simpset_ref;
   820 
   821 * no longer supports theory aliases (via merge) and non-trivial
   822 implicit merge of thms' signatures;
   823 
   824 * most internal names of constants changed due to qualified names;
   825 
   826 * changed Pure/Sequence interface (see Pure/seq.ML);
   827 
   828 
   829 *** General Changes ***
   830 
   831 * hierachically structured name spaces (for consts, types, axms, thms
   832 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
   833 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
   834 isatool fixdots ensures space after dots (e.g. "%x. x"); set
   835 long_names for fully qualified output names; NOTE: ML programs
   836 (special tactics, packages etc.) referring to internal names may have
   837 to be adapted to cope with fully qualified names; in case of severe
   838 backward campatibility problems try setting 'global_names' at compile
   839 time to have enrything declared within a flat name space; one may also
   840 fine tune name declarations in theories via the 'global' and 'local'
   841 section;
   842 
   843 * reimplemented the implicit simpset and claset using the new anytype
   844 data filed in signatures; references simpset:simpset ref etc. are
   845 replaced by functions simpset:unit->simpset and
   846 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
   847 to patch your ML files accordingly;
   848 
   849 * HTML output now includes theory graph data for display with Java
   850 applet or isatool browser; data generated automatically via isatool
   851 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
   852 
   853 * defs may now be conditional; improved rewrite_goals_tac to handle
   854 conditional equations;
   855 
   856 * defs now admits additional type arguments, using TYPE('a) syntax;
   857 
   858 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
   859 creates a new theory node; implicit merge of thms' signatures is
   860 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
   861 transfer:theory->thm->thm in (rare) cases;
   862 
   863 * improved handling of draft signatures / theories; draft thms (and
   864 ctyps, cterms) are automatically promoted to real ones;
   865 
   866 * slightly changed interfaces for oracles: admit many per theory, named
   867 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
   868 
   869 * print_goals: optional output of const types (set show_consts and
   870 show_types);
   871 
   872 * improved output of warnings (###) and errors (***);
   873 
   874 * subgoal_tac displays a warning if the new subgoal has type variables;
   875 
   876 * removed old README and Makefiles;
   877 
   878 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
   879 
   880 * removed obsolete init_pps and init_database;
   881 
   882 * deleted the obsolete tactical STATE, which was declared by
   883     fun STATE tacfun st = tacfun st st;
   884 
   885 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
   886 (which abbreviates $HOME);
   887 
   888 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
   889 use isatool fixseq to adapt your ML programs (this works for fully
   890 qualified references to the Sequence structure only!);
   891 
   892 * use_thy no longer requires writable current directory; it always
   893 reloads .ML *and* .thy file, if either one is out of date;
   894 
   895 
   896 *** Classical Reasoner ***
   897 
   898 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
   899 tactics that use classical reasoning to simplify a subgoal without
   900 splitting it into several subgoals;
   901 
   902 * Safe_tac: like safe_tac but uses the default claset;
   903 
   904 
   905 *** Simplifier ***
   906 
   907 * added simplification meta rules:
   908     (asm_)(full_)simplify: simpset -> thm -> thm;
   909 
   910 * simplifier.ML no longer part of Pure -- has to be loaded by object
   911 logics (again);
   912 
   913 * added prems argument to simplification procedures;
   914 
   915 * HOL, FOL, ZF: added infix function `addsplits':
   916   instead of `<simpset> setloop (split_tac <thms>)'
   917   you can simply write `<simpset> addsplits <thms>'
   918 
   919 
   920 *** Syntax ***
   921 
   922 * TYPE('a) syntax for type reflection terms;
   923 
   924 * no longer handles consts with name "" -- declare as 'syntax' instead;
   925 
   926 * pretty printer: changed order of mixfix annotation preference (again!);
   927 
   928 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
   929 
   930 
   931 *** HOL ***
   932 
   933 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
   934   with `addloop' of the simplifier to faciliate case splitting in premises.
   935 
   936 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
   937 
   938 * HOL/Auth: new protocol proofs including some for the Internet
   939   protocol TLS;
   940 
   941 * HOL/Map: new theory of `maps' a la VDM;
   942 
   943 * HOL/simplifier: simplification procedures nat_cancel_sums for
   944 cancelling out common nat summands from =, <, <= (in)equalities, or
   945 differences; simplification procedures nat_cancel_factor for
   946 cancelling common factor from =, <, <= (in)equalities over natural
   947 sums; nat_cancel contains both kinds of procedures, it is installed by
   948 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
   949 
   950 * HOL/simplifier: terms of the form
   951   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
   952   are rewritten to
   953   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
   954   and those of the form
   955   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
   956   are rewritten to
   957   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
   958 
   959 * HOL/datatype
   960   Each datatype `t' now comes with a theorem `split_t_case' of the form
   961 
   962   P(t_case f1 ... fn x) =
   963      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
   964         ...
   965        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
   966      )
   967 
   968   and a theorem `split_t_case_asm' of the form
   969 
   970   P(t_case f1 ... fn x) =
   971     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
   972         ...
   973        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
   974      )
   975   which can be added to a simpset via `addsplits'. The existing theorems
   976   expand_list_case and expand_option_case have been renamed to
   977   split_list_case and split_option_case.
   978 
   979 * HOL/Arithmetic:
   980   - `pred n' is automatically converted to `n-1'.
   981     Users are strongly encouraged not to use `pred' any longer,
   982     because it will disappear altogether at some point.
   983   - Users are strongly encouraged to write "0 < n" rather than
   984     "n ~= 0". Theorems and proof tools have been modified towards this
   985     `standard'.
   986 
   987 * HOL/Lists:
   988   the function "set_of_list" has been renamed "set" (and its theorems too);
   989   the function "nth" now takes its arguments in the reverse order and
   990   has acquired the infix notation "!" as in "xs!n".
   991 
   992 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
   993 
   994 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
   995   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
   996 
   997 * HOL/record: extensible records with schematic structural subtyping
   998 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
   999 still lacks various theorems and concrete record syntax;
  1000 
  1001 
  1002 *** HOLCF ***
  1003 
  1004 * removed "axioms" and "generated by" sections;
  1005 
  1006 * replaced "ops" section by extended "consts" section, which is capable of
  1007   handling the continuous function space "->" directly;
  1008 
  1009 * domain package:
  1010   . proves theorems immediately and stores them in the theory,
  1011   . creates hierachical name space,
  1012   . now uses normal mixfix annotations (instead of cinfix...),
  1013   . minor changes to some names and values (for consistency),
  1014   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  1015   . separator between mutual domain defs: changed "," to "and",
  1016   . improved handling of sort constraints;  now they have to
  1017     appear on the left-hand side of the equations only;
  1018 
  1019 * fixed LAM <x,y,zs>.b syntax;
  1020 
  1021 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  1022 adm (%x. P (t x)), where P is chainfinite and t continuous;
  1023 
  1024 
  1025 *** FOL and ZF ***
  1026 
  1027 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1028   with `addloop' of the simplifier to faciliate case splitting in premises.
  1029 
  1030 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  1031 in HOL, they strip ALL and --> from proved theorems;
  1032 
  1033 
  1034 
  1035 New in Isabelle94-8 (May 1997)
  1036 ------------------------------
  1037 
  1038 *** General Changes ***
  1039 
  1040 * new utilities to build / run / maintain Isabelle etc. (in parts
  1041 still somewhat experimental); old Makefiles etc. still functional;
  1042 
  1043 * new 'Isabelle System Manual';
  1044 
  1045 * INSTALL text, together with ./configure and ./build scripts;
  1046 
  1047 * reimplemented type inference for greater efficiency, better error
  1048 messages and clean internal interface;
  1049 
  1050 * prlim command for dealing with lots of subgoals (an easier way of
  1051 setting goals_limit);
  1052 
  1053 
  1054 *** Syntax ***
  1055 
  1056 * supports alternative (named) syntax tables (parser and pretty
  1057 printer); internal interface is provided by add_modesyntax(_i);
  1058 
  1059 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  1060 be used in conjunction with the Isabelle symbol font; uses the
  1061 "symbols" syntax table;
  1062 
  1063 * added token_translation interface (may translate name tokens in
  1064 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  1065 the current print_mode); IMPORTANT: user print translation functions
  1066 are responsible for marking newly introduced bounds
  1067 (Syntax.mark_boundT);
  1068 
  1069 * token translations for modes "xterm" and "xterm_color" that display
  1070 names in bold, underline etc. or colors (which requires a color
  1071 version of xterm);
  1072 
  1073 * infixes may now be declared with names independent of their syntax;
  1074 
  1075 * added typed_print_translation (like print_translation, but may
  1076 access type of constant);
  1077 
  1078 
  1079 *** Classical Reasoner ***
  1080 
  1081 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  1082 some limitations.  Blast_tac...
  1083   + ignores addss, addbefore, addafter; this restriction is intrinsic
  1084   + ignores elimination rules that don't have the correct format
  1085         (the conclusion MUST be a formula variable)
  1086   + ignores types, which can make HOL proofs fail
  1087   + rules must not require higher-order unification, e.g. apply_type in ZF
  1088     [message "Function Var's argument not a bound variable" relates to this]
  1089   + its proof strategy is more general but can actually be slower
  1090 
  1091 * substitution with equality assumptions no longer permutes other
  1092 assumptions;
  1093 
  1094 * minor changes in semantics of addafter (now called addaltern); renamed
  1095 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  1096 (and access functions for it);
  1097 
  1098 * improved combination of classical reasoner and simplifier:
  1099   + functions for handling clasimpsets
  1100   + improvement of addss: now the simplifier is called _after_ the
  1101     safe steps.
  1102   + safe variant of addss called addSss: uses safe simplifications
  1103     _during_ the safe steps. It is more complete as it allows multiple
  1104     instantiations of unknowns (e.g. with slow_tac).
  1105 
  1106 *** Simplifier ***
  1107 
  1108 * added interface for simplification procedures (functions that
  1109 produce *proven* rewrite rules on the fly, depending on current
  1110 redex);
  1111 
  1112 * ordering on terms as parameter (used for ordered rewriting);
  1113 
  1114 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  1115 
  1116 * the solver is now split into a safe and an unsafe part.
  1117 This should be invisible for the normal user, except that the
  1118 functions setsolver and addsolver have been renamed to setSolver and
  1119 addSolver; added safe_asm_full_simp_tac;
  1120 
  1121 
  1122 *** HOL ***
  1123 
  1124 * a generic induction tactic `induct_tac' which works for all datatypes and
  1125 also for type `nat';
  1126 
  1127 * a generic case distinction tactic `exhaust_tac' which works for all
  1128 datatypes and also for type `nat';
  1129 
  1130 * each datatype comes with a function `size';
  1131 
  1132 * patterns in case expressions allow tuple patterns as arguments to
  1133 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  1134 
  1135 * primrec now also works with type nat;
  1136 
  1137 * recdef: a new declaration form, allows general recursive functions to be
  1138 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  1139 
  1140 * the constant for negation has been renamed from "not" to "Not" to
  1141 harmonize with FOL, ZF, LK, etc.;
  1142 
  1143 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  1144 infinite lists;
  1145 
  1146 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  1147 
  1148 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  1149 problems in commutative rings, using axiomatic type classes for + and *;
  1150 
  1151 * more examples in HOL/MiniML and HOL/Auth;
  1152 
  1153 * more default rewrite rules for quantifiers, union/intersection;
  1154 
  1155 * a new constant `arbitrary == @x.False';
  1156 
  1157 * HOLCF/IOA replaces old HOL/IOA;
  1158 
  1159 * HOLCF changes: derived all rules and arities
  1160   + axiomatic type classes instead of classes
  1161   + typedef instead of faking type definitions
  1162   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  1163   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  1164   + eliminated the types void, one, tr
  1165   + use unit lift and bool lift (with translations) instead of one and tr
  1166   + eliminated blift from Lift3.thy (use Def instead of blift)
  1167   all eliminated rules are derived as theorems --> no visible changes ;
  1168 
  1169 
  1170 *** ZF ***
  1171 
  1172 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  1173 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  1174 as ZF_cs addSIs [equalityI];
  1175 
  1176 
  1177 
  1178 New in Isabelle94-7 (November 96)
  1179 ---------------------------------
  1180 
  1181 * allowing negative levels (as offsets) in prlev and choplev;
  1182 
  1183 * super-linear speedup for large simplifications;
  1184 
  1185 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  1186 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  1187 FAIL); can suppress it using the command Delsimps (ex_simps @
  1188 all_simps); De Morgan laws are also now included, by default;
  1189 
  1190 * improved printing of ==>  :  ~:
  1191 
  1192 * new object-logic "Sequents" adds linear logic, while replacing LK
  1193 and Modal (thanks to Sara Kalvala);
  1194 
  1195 * HOL/Auth: correctness proofs for authentication protocols;
  1196 
  1197 * HOL: new auto_tac combines rewriting and classical reasoning (many
  1198 examples on HOL/Auth);
  1199 
  1200 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  1201 the rewriter and classical reasoner simultaneously;
  1202 
  1203 * function uresult no longer returns theorems in "standard" format;
  1204 regain previous version by: val uresult = standard o uresult;
  1205 
  1206 
  1207 
  1208 New in Isabelle94-6
  1209 -------------------
  1210 
  1211 * oracles -- these establish an interface between Isabelle and trusted
  1212 external reasoners, which may deliver results as theorems;
  1213 
  1214 * proof objects (in particular record all uses of oracles);
  1215 
  1216 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  1217 
  1218 * "constdefs" section in theory files;
  1219 
  1220 * "primrec" section (HOL) no longer requires names;
  1221 
  1222 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  1223 
  1224 
  1225 
  1226 New in Isabelle94-5
  1227 -------------------
  1228 
  1229 * reduced space requirements;
  1230 
  1231 * automatic HTML generation from theories;
  1232 
  1233 * theory files no longer require "..." (quotes) around most types;
  1234 
  1235 * new examples, including two proofs of the Church-Rosser theorem;
  1236 
  1237 * non-curried (1994) version of HOL is no longer distributed;
  1238 
  1239 
  1240 
  1241 New in Isabelle94-4
  1242 -------------------
  1243 
  1244 * greatly reduced space requirements;
  1245 
  1246 * theory files (.thy) no longer require \...\ escapes at line breaks;
  1247 
  1248 * searchable theorem database (see the section "Retrieving theorems" on
  1249 page 8 of the Reference Manual);
  1250 
  1251 * new examples, including Grabczewski's monumental case study of the
  1252 Axiom of Choice;
  1253 
  1254 * The previous version of HOL renamed to Old_HOL;
  1255 
  1256 * The new version of HOL (previously called CHOL) uses a curried syntax
  1257 for functions.  Application looks like f a b instead of f(a,b);
  1258 
  1259 * Mutually recursive inductive definitions finally work in HOL;
  1260 
  1261 * In ZF, pattern-matching on tuples is now available in all abstractions and
  1262 translates to the operator "split";
  1263 
  1264 
  1265 
  1266 New in Isabelle94-3
  1267 -------------------
  1268 
  1269 * new infix operator, addss, allowing the classical reasoner to
  1270 perform simplification at each step of its search.  Example:
  1271         fast_tac (cs addss ss)
  1272 
  1273 * a new logic, CHOL, the same as HOL, but with a curried syntax
  1274 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  1275 look like (a,b) instead of <a,b>;
  1276 
  1277 * PLEASE NOTE: CHOL will eventually replace HOL!
  1278 
  1279 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  1280 It translates to the operator "split".  A new theory of integers is available;
  1281 
  1282 * In ZF, integer numerals now denote two's-complement binary integers.
  1283 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  1284 
  1285 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  1286 of the Axiom of Choice;
  1287 
  1288 
  1289 
  1290 New in Isabelle94-2
  1291 -------------------
  1292 
  1293 * Significantly faster resolution;
  1294 
  1295 * the different sections in a .thy file can now be mixed and repeated
  1296 freely;
  1297 
  1298 * Database of theorems for FOL, HOL and ZF.  New
  1299 commands including qed, qed_goal and bind_thm store theorems in the database.
  1300 
  1301 * Simple database queries: return a named theorem (get_thm) or all theorems of
  1302 a given theory (thms_of), or find out what theory a theorem was proved in
  1303 (theory_of_thm);
  1304 
  1305 * Bugs fixed in the inductive definition and datatype packages;
  1306 
  1307 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  1308 and HOL_dup_cs obsolete;
  1309 
  1310 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  1311 have been removed;
  1312 
  1313 * Simpler definition of function space in ZF;
  1314 
  1315 * new results about cardinal and ordinal arithmetic in ZF;
  1316 
  1317 * 'subtype' facility in HOL for introducing new types as subsets of existing
  1318 types;
  1319 
  1320 
  1321 $Id$