NEWS
author wenzelm
Thu Feb 21 20:11:32 2002 +0100 (2002-02-21)
changeset 12924 02eb40cde931
parent 12917 0fd3caa5d8b2
child 12964 2ac9265b2cd5
permissions -rw-r--r--
* HOL: removed obsolete theorem "optionE";
     1 
     2 Isabelle NEWS -- history user-relevant changes
     3 ==============================================
     4 
     5 New in Isabelle2002 (January 2002)
     6 ----------------------------------
     7 
     8 *** Document preparation ***
     9 
    10 * greatly simplified document preparation setup, including more
    11 graceful interpretation of isatool usedir -i/-d/-D options, and more
    12 instructive isatool mkdir; users should basically be able to get
    13 started with "isatool mkdir HOL Test && isatool make"; alternatively,
    14 users may run a separate document processing stage manually like this:
    15 "isatool usedir -D output HOL Test && isatool document Test/output";
    16 
    17 * theory dependency graph may now be incorporated into documents;
    18 isatool usedir -g true will produce session_graph.eps/.pdf for use
    19 with \includegraphics of LaTeX;
    20 
    21 * proper spacing of consecutive markup elements, especially text
    22 blocks after section headings;
    23 
    24 * support bold style (for single symbols only), input syntax is like
    25 this: "\<^bold>\<alpha>" or "\<^bold>A";
    26 
    27 * \<bullet> is now output as bold \cdot by default, which looks much
    28 better in printed text;
    29 
    30 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
    31 note that these symbols are currently unavailable in Proof General /
    32 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
    33 
    34 * isatool latex no longer depends on changed TEXINPUTS, instead
    35 isatool document copies the Isabelle style files to the target
    36 location;
    37 
    38 
    39 *** Isar ***
    40 
    41 * Pure/Provers: improved proof by cases and induction;
    42   - 'case' command admits impromptu naming of parameters (such as
    43     "case (Suc n)");
    44   - 'induct' method divinates rule instantiation from the inductive
    45     claim; no longer requires excessive ?P bindings for proper
    46     instantiation of cases;
    47   - 'induct' method properly enumerates all possibilities of set/type
    48     rules; as a consequence facts may be also passed through *type*
    49     rules without further ado;
    50   - 'induct' method now derives symbolic cases from the *rulified*
    51     rule (before it used to rulify cases stemming from the internal
    52     atomized version); this means that the context of a non-atomic
    53     statement becomes is included in the hypothesis, avoiding the
    54     slightly cumbersome show "PROP ?case" form;
    55   - 'induct' may now use elim-style induction rules without chaining
    56     facts, using ``missing'' premises from the goal state; this allows
    57     rules stemming from inductive sets to be applied in unstructured
    58     scripts, while still benefitting from proper handling of non-atomic
    59     statements; NB: major inductive premises need to be put first, all
    60     the rest of the goal is passed through the induction;
    61   - 'induct' proper support for mutual induction involving non-atomic
    62     rule statements (uses the new concept of simultaneous goals, see
    63     below);
    64   - append all possible rule selections, but only use the first
    65     success (no backtracking);
    66   - removed obsolete "(simplified)" and "(stripped)" options of methods;
    67   - undeclared rule case names default to numbers 1, 2, 3, ...;
    68   - added 'print_induct_rules' (covered by help item in recent Proof
    69     General versions);
    70   - moved induct/cases attributes to Pure, methods to Provers;
    71   - generic method setup instantiated for FOL and HOL;
    72 
    73 * Pure: support multiple simultaneous goal statements, for example
    74 "have a: A and b: B" (same for 'theorem' etc.); being a pure
    75 meta-level mechanism, this acts as if several individual goals had
    76 been stated separately; in particular common proof methods need to be
    77 repeated in order to cover all claims; note that a single elimination
    78 step is *not* sufficient to establish the two conjunctions, so this
    79 fails:
    80 
    81   assume "A & B" then have A and B ..   (*".." fails*)
    82 
    83 better use "obtain" in situations as above; alternative refer to
    84 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
    85 
    86 * Pure: proper integration with ``locales''; unlike the original
    87 version by Florian Kammüller, Isar locales package high-level proof
    88 contexts rather than raw logical ones (e.g. we admit to include
    89 attributes everywhere); operations on locales include merge and
    90 rename; e.g. see HOL/ex/Locales.thy;
    91 
    92 * Pure: the following commands have been ``localized'', supporting a
    93 target locale specification "(in name)": 'lemma', 'theorem',
    94 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
    95 stored both within the locale and at the theory level (exported and
    96 qualified by the locale name);
    97 
    98 * Pure: theory goals now support ad-hoc contexts, which are discharged
    99 in the result, as in ``lemma (assumes A and B) K: A .''; syntax
   100 coincides with that of a locale body;
   101 
   102 * Pure: renamed "antecedent" case to "rule_context";
   103 
   104 * Pure: added 'corollary' command;
   105 
   106 * Pure: fixed 'token_translation' command;
   107 
   108 * Pure: removed obsolete 'exported' attribute;
   109 
   110 * Pure: dummy pattern "_" in is/let is now automatically lifted over
   111 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
   112 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
   113 
   114 * Pure: method 'atomize' presents local goal premises as object-level
   115 statements (atomic meta-level propositions); setup controlled via
   116 rewrite rules declarations of 'atomize' attribute; example
   117 application: 'induct' method with proper rule statements in improper
   118 proof *scripts*;
   119 
   120 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
   121 now consider the syntactic context of assumptions, giving a better
   122 chance to get type-inference of the arguments right (this is
   123 especially important for locales);
   124 
   125 * Pure: "sorry" no longer requires quick_and_dirty in interactive
   126 mode;
   127 
   128 * Pure/obtain: the formal conclusion "thesis", being marked as
   129 ``internal'', may no longer be reference directly in the text;
   130 potential INCOMPATIBILITY, may need to use "?thesis" in rare
   131 situations;
   132 
   133 * Pure: generic 'sym' attribute which declares a rule both as pure
   134 'elim?' and for the 'symmetric' operation;
   135 
   136 * Pure: marginal comments ``--'' may now occur just anywhere in the
   137 text; the fixed correlation with particular command syntax has been
   138 discontinued;
   139 
   140 * Pure/Provers/classical: simplified integration with pure rule
   141 attributes and methods; the classical "intro?/elim?/dest?"
   142 declarations coincide with the pure ones; the "rule" method no longer
   143 includes classically swapped intros; "intro" and "elim" methods no
   144 longer pick rules from the context; also got rid of ML declarations
   145 AddXIs/AddXEs/AddXDs; all of this has some potential for
   146 INCOMPATIBILITY;
   147 
   148 * Provers/classical: attribute 'swapped' produces classical inversions
   149 of introduction rules;
   150 
   151 * Provers/simplifier: 'simplified' attribute may refer to explicit
   152 rules instead of full simplifier context; 'iff' attribute handles
   153 conditional rules;
   154 
   155 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
   156 
   157 * HOL: 'recdef' now fails on unfinished automated proofs, use
   158 "(permissive)" option to recover old behavior;
   159 
   160 * HOL: 'inductive' no longer features separate (collective) attributes
   161 for 'intros' (was found too confusing);
   162 
   163 * HOL: properly declared induction rules less_induct and
   164 wf_induct_rule;
   165 
   166 
   167 *** HOL ***
   168 
   169 * HOL: moved over to sane numeral syntax; the new policy is as
   170 follows:
   171 
   172   - 0 and 1 are polymorphic constants, which are defined on any
   173   numeric type (nat, int, real etc.);
   174 
   175   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
   176   binary representation internally;
   177 
   178   - type nat has special constructor Suc, and generally prefers Suc 0
   179   over 1::nat and Suc (Suc 0) over 2::nat;
   180 
   181 This change may cause significant problems of INCOMPATIBILITY; here
   182 are some hints on converting existing sources:
   183 
   184   - due to the new "num" token, "-0" and "-1" etc. are now atomic
   185   entities, so expressions involving "-" (unary or binary minus) need
   186   to be spaced properly;
   187 
   188   - existing occurrences of "1" may need to be constraint "1::nat" or
   189   even replaced by Suc 0; similar for old "2";
   190 
   191   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
   192 
   193   - remove all special provisions on numerals in proofs;
   194 
   195 * HOL: simp rules nat_number_of expand numerals on nat to Suc/0
   196 representation (depends on bin_arith_simps in the default context);
   197 
   198 * HOL: symbolic syntax for x^2 (numeral 2);
   199 
   200 * HOL: the class of all HOL types is now called "type" rather than
   201 "term"; INCOMPATIBILITY, need to adapt references to this type class
   202 in axclass/classes, instance/arities, and (usually rare) occurrences
   203 in typings (of consts etc.); internally the class is called
   204 "HOL.type", ML programs should refer to HOLogic.typeS;
   205 
   206 * HOL/record package improvements:
   207   - new derived operations "fields" to build a partial record section,
   208     "extend" to promote a fixed record to a record scheme, and
   209     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
   210     declared as simp by default;
   211   - shared operations ("more", "fields", etc.) now need to be always
   212     qualified) --- potential INCOMPATIBILITY;
   213   - removed "make_scheme" operations (use "make" with "extend") --
   214     INCOMPATIBILITY;
   215   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
   216   - provides cases/induct rules for use with corresponding Isar
   217     methods (for concrete records, record schemes, concrete more
   218     parts, and schematic more parts -- in that order);
   219   - internal definitions directly based on a light-weight abstract
   220     theory of product types over typedef rather than datatype;
   221 
   222 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
   223 
   224 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
   225 (beware of argument permutation!);
   226 
   227 * HOL: linorder_less_split superseded by linorder_cases;
   228 
   229 * HOL/List: "nodups" renamed to "distinct";
   230 
   231 * HOL: added "The" definite description operator; move Hilbert's "Eps"
   232 to peripheral theory "Hilbert_Choice";
   233 
   234 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
   235 in this (rare) case use:
   236 
   237   delSWrapper "split_all_tac"
   238   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
   239 
   240 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
   241 MAY FAIL;
   242 
   243 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
   244 Isabelle's type classes, ^ on functions and relations has too general
   245 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
   246 necessary to attach explicit type constraints;
   247 
   248 * HOL/Relation: the prefix name of the infix "O" has been changed from
   249 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
   250 renamed accordingly (eg "compI" -> "rel_compI").
   251 
   252 * HOL: syntax translations now work properly with numerals and records
   253 expressions;
   254 
   255 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
   256 of "lam" -- INCOMPATIBILITY;
   257 
   258 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
   259 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
   260 renamed "Product_Type.unit";
   261 
   262 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
   263 
   264 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
   265 the "cases" method);
   266 
   267 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
   268 Florian Kammüller);
   269 
   270 * HOL/IMP: updated and converted to new-style theory format; several
   271 parts turned into readable document, with proper Isar proof texts and
   272 some explanations (by Gerwin Klein);
   273 
   274 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
   275 
   276 * HOL-Hyperreal is now a logic image;
   277 
   278 
   279 *** HOLCF ***
   280 
   281 * Isar: consts/constdefs supports mixfix syntax for continuous
   282 operations;
   283 
   284 * Isar: domain package adapted to new-style theory format, e.g. see
   285 HOLCF/ex/Dnat.thy;
   286 
   287 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
   288 potential INCOMPATIBILITY; now use plain induct_tac instead of former
   289 lift.induct_tac, always use UU instead of Undef;
   290 
   291 * HOLCF/IMP: updated and converted to new-style theory;
   292 
   293 
   294 *** ZF ***
   295 
   296 * Isar: proper integration of logic-specific tools and packages,
   297 including theory commands '(co)inductive', '(co)datatype',
   298 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
   299 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
   300 
   301 * theory Main no longer includes AC; for the Axiom of Choice, base
   302 your theory on Main_ZFC;
   303 
   304 * the integer library now covers quotients and remainders, with many
   305 laws relating division to addition, multiplication, etc.;
   306 
   307 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
   308 typeless version of the formalism;
   309 
   310 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory format;
   311 
   312 * ZF/Induct: new directory for examples of inductive definitions,
   313 including theory Multiset for multiset orderings; converted to
   314 new-style theory format;
   315 
   316 * Many new theorems about lists, ordinals, etc.;
   317 
   318 
   319 *** General ***
   320 
   321 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
   322 variable proof controls level of detail: 0 = no proofs (only oracle
   323 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
   324 also ref manual for further ML interfaces;
   325 
   326 * Pure/axclass: removed obsolete ML interface
   327 goal_subclass/goal_arity;
   328 
   329 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
   330 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
   331 separate tokens, so expressions involving minus need to be spaced
   332 properly;
   333 
   334 * Pure/syntax: support non-oriented infixes, using keyword "infix"
   335 rather than "infixl" or "infixr";
   336 
   337 * Pure/syntax: concrete syntax for dummy type variables admits genuine
   338 sort constraint specifications in type inference; e.g. "x::_::foo"
   339 ensures that the type of "x" is of sort "foo" (but not necessarily a
   340 type variable);
   341 
   342 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
   343 control output of nested => (types); the default behavior is
   344 "type_brackets";
   345 
   346 * Pure/syntax: builtin parse translation for "_constify" turns valued
   347 tokens into AST constants;
   348 
   349 * Pure/syntax: prefer later declarations of translations and print
   350 translation functions; potential INCOMPATIBILITY: need to reverse
   351 multiple declarations for same syntax element constant;
   352 
   353 * Pure/show_hyps reset by default (in accordance to existing Isar
   354 practice);
   355 
   356 * Provers/classical: renamed addaltern to addafter, addSaltern to
   357 addSafter;
   358 
   359 * Provers/clasimp: ``iff'' declarations now handle conditional rules
   360 as well;
   361 
   362 * system: tested support for MacOS X; should be able to get Isabelle +
   363 Proof General to work in a plain Terminal after installing Poly/ML
   364 (e.g. from the Isabelle distribution area) and GNU bash alone
   365 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
   366 support requires further installations, e.g. from
   367 http://fink.sourceforge.net/);
   368 
   369 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
   370 
   371 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
   372 of 40 MB), cf. ML_OPTIONS;
   373 
   374 * system: Proof General keywords specification is now part of the
   375 Isabelle distribution (see etc/isar-keywords.el);
   376 
   377 * system: support for persistent Proof General sessions (refrain from
   378 outdating all loaded theories on startup); user may create writable
   379 logic images like this: ``isabelle -q HOL Test'';
   380 
   381 * system: smart selection of Isabelle process versus Isabelle
   382 interface, accommodates case-insensitive file systems (e.g. HFS+); may
   383 run both "isabelle" and "Isabelle" even if file names are badly
   384 damaged (executable inspects the case of the first letter of its own
   385 name); added separate "isabelle-process" and "isabelle-interface";
   386 
   387 * system: refrain from any attempt at filtering input streams; no
   388 longer support ``8bit'' encoding of old isabelle font, instead proper
   389 iso-latin characters may now be used; the related isatools
   390 "symbolinput" and "nonascii" have disappeared as well;
   391 
   392 * system: removed old "xterm" interface (the print modes "xterm" and
   393 "xterm_color" are still available for direct use in a suitable
   394 terminal);
   395 
   396 
   397 
   398 New in Isabelle99-2 (February 2001)
   399 -----------------------------------
   400 
   401 *** Overview of INCOMPATIBILITIES ***
   402 
   403 * HOL: please note that theories in the Library and elsewhere often use the
   404 new-style (Isar) format; to refer to their theorems in an ML script you must
   405 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
   406 
   407 * HOL: inductive package no longer splits induction rule aggressively,
   408 but only as far as specified by the introductions given; the old
   409 format may be recovered via ML function complete_split_rule or attribute
   410 'split_rule (complete)';
   411 
   412 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
   413 gfp_Tarski to gfp_unfold;
   414 
   415 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
   416 
   417 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
   418 relation); infix "^^" has been renamed "``"; infix "``" has been
   419 renamed "`"; "univalent" has been renamed "single_valued";
   420 
   421 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
   422 operation;
   423 
   424 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
   425 
   426 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
   427 
   428 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
   429 consequence, it is no longer monotonic wrt. the local goal context
   430 (which is now passed through the inductive cases);
   431 
   432 * Document preparation: renamed standard symbols \<ll> to \<lless> and
   433 \<gg> to \<ggreater>;
   434 
   435 
   436 *** Document preparation ***
   437 
   438 * \isabellestyle{NAME} selects version of Isabelle output (currently
   439 available: are "it" for near math-mode best-style output, "sl" for
   440 slanted text style, and "tt" for plain type-writer; if no
   441 \isabellestyle command is given, output is according to slanted
   442 type-writer);
   443 
   444 * support sub/super scripts (for single symbols only), input syntax is
   445 like this: "A\<^sup>*" or "A\<^sup>\<star>";
   446 
   447 * some more standard symbols; see Appendix A of the system manual for
   448 the complete list of symbols defined in isabellesym.sty;
   449 
   450 * improved isabelle style files; more abstract symbol implementation
   451 (should now use \isamath{...} and \isatext{...} in custom symbol
   452 definitions);
   453 
   454 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
   455 state; Note that presentation of goal states does not conform to
   456 actual human-readable proof documents.  Please do not include goal
   457 states into document output unless you really know what you are doing!
   458 
   459 * proper indentation of antiquoted output with proportional LaTeX
   460 fonts;
   461 
   462 * no_document ML operator temporarily disables LaTeX document
   463 generation;
   464 
   465 * isatool unsymbolize tunes sources for plain ASCII communication;
   466 
   467 
   468 *** Isar ***
   469 
   470 * Pure: Isar now suffers initial goal statements to contain unbound
   471 schematic variables (this does not conform to actual readable proof
   472 documents, due to unpredictable outcome and non-compositional proof
   473 checking); users who know what they are doing may use schematic goals
   474 for Prolog-style synthesis of proven results;
   475 
   476 * Pure: assumption method (an implicit finishing) now handles actual
   477 rules as well;
   478 
   479 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
   480 initial goal, declare "that" only as Pure intro (only for single
   481 steps); the "that" rule assumption may now be involved in implicit
   482 finishing, thus ".." becomes a feasible for trivial obtains;
   483 
   484 * Pure: default proof step now includes 'intro_classes'; thus trivial
   485 instance proofs may be performed by "..";
   486 
   487 * Pure: ?thesis / ?this / "..." now work for pure meta-level
   488 statements as well;
   489 
   490 * Pure: more robust selection of calculational rules;
   491 
   492 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
   493 rule (as well as the assumption rule);
   494 
   495 * Pure: 'thm_deps' command visualizes dependencies of theorems and
   496 lemmas, using the graph browser tool;
   497 
   498 * Pure: predict failure of "show" in interactive mode;
   499 
   500 * Pure: 'thms_containing' now takes actual terms as arguments;
   501 
   502 * HOL: improved method 'induct' --- now handles non-atomic goals
   503 (potential INCOMPATIBILITY); tuned error handling;
   504 
   505 * HOL: cases and induct rules now provide explicit hints about the
   506 number of facts to be consumed (0 for "type" and 1 for "set" rules);
   507 any remaining facts are inserted into the goal verbatim;
   508 
   509 * HOL: local contexts (aka cases) may now contain term bindings as
   510 well; the 'cases' and 'induct' methods new provide a ?case binding for
   511 the result to be shown in each case;
   512 
   513 * HOL: added 'recdef_tc' command;
   514 
   515 * isatool convert assists in eliminating legacy ML scripts;
   516 
   517 
   518 *** HOL ***
   519 
   520 * HOL/Library: a collection of generic theories to be used together
   521 with main HOL; the theory loader path already includes this directory
   522 by default; the following existing theories have been moved here:
   523 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
   524 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
   525 
   526 * HOL/Unix: "Some aspects of Unix file-system security", a typical
   527 modelling and verification task performed in Isabelle/HOL +
   528 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
   529 
   530 * HOL/Algebra: special summation operator SUM no longer exists, it has
   531 been replaced by setsum; infix 'assoc' now has priority 50 (like
   532 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
   533 'domain', this makes the theory consistent with mathematical
   534 literature;
   535 
   536 * HOL basics: added overloaded operations "inverse" and "divide"
   537 (infix "/"), syntax for generic "abs" operation, generic summation
   538 operator \<Sum>;
   539 
   540 * HOL/typedef: simplified package, provide more useful rules (see also
   541 HOL/subset.thy);
   542 
   543 * HOL/datatype: induction rule for arbitrarily branching datatypes is
   544 now expressed as a proper nested rule (old-style tactic scripts may
   545 require atomize_strip_tac to cope with non-atomic premises);
   546 
   547 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
   548 to "split_conv" (old name still available for compatibility);
   549 
   550 * HOL: improved concrete syntax for strings (e.g. allows translation
   551 rules with string literals);
   552 
   553 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
   554  and Fleuriot's mechanization of analysis, including the transcendental
   555  functions for the reals;
   556 
   557 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
   558 
   559 
   560 *** CTT ***
   561 
   562 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
   563 "lam" is displayed as TWO lambda-symbols
   564 
   565 * CTT: theory Main now available, containing everything (that is, Bool
   566 and Arith);
   567 
   568 
   569 *** General ***
   570 
   571 * Pure: the Simplifier has been implemented properly as a derived rule
   572 outside of the actual kernel (at last!); the overall performance
   573 penalty in practical applications is about 50%, while reliability of
   574 the Isabelle inference kernel has been greatly improved;
   575 
   576 * print modes "brackets" and "no_brackets" control output of nested =>
   577 (types) and ==> (props); the default behaviour is "brackets";
   578 
   579 * Provers: fast_tac (and friends) now handle actual object-logic rules
   580 as assumptions as well;
   581 
   582 * system: support Poly/ML 4.0;
   583 
   584 * system: isatool install handles KDE version 1 or 2;
   585 
   586 
   587 
   588 New in Isabelle99-1 (October 2000)
   589 ----------------------------------
   590 
   591 *** Overview of INCOMPATIBILITIES ***
   592 
   593 * HOL: simplification of natural numbers is much changed; to partly
   594 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
   595 issue the following ML commands:
   596 
   597   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
   598   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
   599 
   600 * HOL: simplification no longer dives into case-expressions; this is
   601 controlled by "t.weak_case_cong" for each datatype t;
   602 
   603 * HOL: nat_less_induct renamed to less_induct;
   604 
   605 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
   606 fixsome to patch .thy and .ML sources automatically;
   607 
   608   select_equality  -> some_equality
   609   select_eq_Ex     -> some_eq_ex
   610   selectI2EX       -> someI2_ex
   611   selectI2         -> someI2
   612   selectI          -> someI
   613   select1_equality -> some1_equality
   614   Eps_sym_eq       -> some_sym_eq_trivial
   615   Eps_eq           -> some_eq_trivial
   616 
   617 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
   618 
   619 * HOL: removed obsolete theorem binding expand_if (refer to split_if
   620 instead);
   621 
   622 * HOL: the recursion equations generated by 'recdef' are now called
   623 f.simps instead of f.rules;
   624 
   625 * HOL: qed_spec_mp now also handles bounded ALL as well;
   626 
   627 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
   628 sometimes be needed;
   629 
   630 * HOL: the constant for "f``x" is now "image" rather than "op ``";
   631 
   632 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
   633 
   634 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
   635 product is now "<*>" instead of "Times"; the lexicographic product is
   636 now "<*lex*>" instead of "**";
   637 
   638 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
   639 of main HOL, but was unused); better use HOL's datatype package;
   640 
   641 * HOL: removed "symbols" syntax for constant "override" of theory Map;
   642 the old syntax may be recovered as follows:
   643 
   644   syntax (symbols)
   645     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
   646       (infixl "\\<oplus>" 100)
   647 
   648 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   649 
   650 * HOL/ML: even fewer consts are declared as global (see theories Ord,
   651 Lfp, Gfp, WF); this only affects ML packages that refer to const names
   652 internally;
   653 
   654 * HOL and ZF: syntax for quotienting wrt an equivalence relation
   655 changed from A/r to A//r;
   656 
   657 * ZF: new treatment of arithmetic (nat & int) may break some old
   658 proofs;
   659 
   660 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
   661 rulify -> rule_format, elimify -> elim_format, ...);
   662 
   663 * Isar/Provers: intro/elim/dest attributes changed; renamed
   664 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
   665 should have to change intro!! to intro? only); replaced "delrule" by
   666 "rule del";
   667 
   668 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
   669 
   670 * Provers: strengthened force_tac by using new first_best_tac;
   671 
   672 * LaTeX document preparation: several changes of isabelle.sty (see
   673 lib/texinputs);
   674 
   675 
   676 *** Document preparation ***
   677 
   678 * formal comments (text blocks etc.) in new-style theories may now
   679 contain antiquotations of thm/prop/term/typ/text to be presented
   680 according to latex print mode; concrete syntax is like this:
   681 @{term[show_types] "f(x) = a + x"};
   682 
   683 * isatool mkdir provides easy setup of Isabelle session directories,
   684 including proper document sources;
   685 
   686 * generated LaTeX sources are now deleted after successful run
   687 (isatool document -c); may retain a copy somewhere else via -D option
   688 of isatool usedir;
   689 
   690 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
   691 style files, achieving self-contained LaTeX sources and simplifying
   692 LaTeX debugging;
   693 
   694 * old-style theories now produce (crude) LaTeX output as well;
   695 
   696 * browser info session directories are now self-contained (may be put
   697 on WWW server seperately); improved graphs of nested sessions; removed
   698 graph for 'all sessions';
   699 
   700 * several improvements in isabelle style files; \isabellestyle{it}
   701 produces fake math mode output; \isamarkupheader is now \section by
   702 default; see lib/texinputs/isabelle.sty etc.;
   703 
   704 
   705 *** Isar ***
   706 
   707 * Isar/Pure: local results and corresponding term bindings are now
   708 subject to Hindley-Milner polymorphism (similar to ML); this
   709 accommodates incremental type-inference very nicely;
   710 
   711 * Isar/Pure: new derived language element 'obtain' supports
   712 generalized existence reasoning;
   713 
   714 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
   715 support accumulation of results, without applying any rules yet;
   716 useful to collect intermediate results without explicit name
   717 references, and for use with transitivity rules with more than 2
   718 premises;
   719 
   720 * Isar/Pure: scalable support for case-analysis type proofs: new
   721 'case' language element refers to local contexts symbolically, as
   722 produced by certain proof methods; internally, case names are attached
   723 to theorems as "tags";
   724 
   725 * Isar/Pure: theory command 'hide' removes declarations from
   726 class/type/const name spaces;
   727 
   728 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
   729 indicate potential overloading;
   730 
   731 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
   732 
   733 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
   734 "{a,b,c}" instead of {a,b,c};
   735 
   736 * Isar/Pure now provides its own version of intro/elim/dest
   737 attributes; useful for building new logics, but beware of confusion
   738 with the version in Provers/classical;
   739 
   740 * Isar/Pure: the local context of (non-atomic) goals is provided via
   741 case name 'antecedent';
   742 
   743 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
   744 to the current context is now done automatically);
   745 
   746 * Isar/Pure: theory command 'method_setup' provides a simple interface
   747 for definining proof methods in ML;
   748 
   749 * Isar/Provers: intro/elim/dest attributes changed; renamed
   750 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
   751 most cases, one should have to change intro!! to intro? only);
   752 replaced "delrule" by "rule del";
   753 
   754 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
   755 'symmetric' attribute (the latter supercedes [RS sym]);
   756 
   757 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
   758 method modifier); 'simp' method: 'only:' modifier removes loopers as
   759 well (including splits);
   760 
   761 * Isar/Provers: Simplifier and Classical methods now support all kind
   762 of modifiers used in the past, including 'cong', 'iff', etc.
   763 
   764 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
   765 of Simplifier and Classical reasoner);
   766 
   767 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
   768 now support named cases; major packages (inductive, datatype, primrec,
   769 recdef) support case names and properly name parameters;
   770 
   771 * Isar/HOL: new transitivity rules for substitution in inequalities --
   772 monotonicity conditions are extracted to be proven at end of
   773 calculations;
   774 
   775 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
   776 method anyway;
   777 
   778 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
   779 split_if split_if_asm; datatype package provides theorems foo.splits =
   780 foo.split foo.split_asm for each datatype;
   781 
   782 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
   783 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
   784 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
   785 use "(cases (simplified))" method in proper proof texts);
   786 
   787 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
   788 
   789 * Isar: names of theorems etc. may be natural numbers as well;
   790 
   791 * Isar: 'pr' command: optional arguments for goals_limit and
   792 ProofContext.prems_limit; no longer prints theory contexts, but only
   793 proof states;
   794 
   795 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
   796 additional print modes to be specified; e.g. "pr(latex)" will print
   797 proof state according to the Isabelle LaTeX style;
   798 
   799 * Isar: improved support for emulating tactic scripts, including proof
   800 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
   801 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
   802 (for HOL datatypes);
   803 
   804 * Isar: simplified (more robust) goal selection of proof methods: 1st
   805 goal, all goals, or explicit goal specifier (tactic emulation); thus
   806 'proof method scripts' have to be in depth-first order;
   807 
   808 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
   809 
   810 * Isar: removed 'help' command, which hasn't been too helpful anyway;
   811 should instead use individual commands for printing items
   812 (print_commands, print_methods etc.);
   813 
   814 * Isar: added 'nothing' --- the empty list of theorems;
   815 
   816 
   817 *** HOL ***
   818 
   819 * HOL/MicroJava: formalization of a fragment of Java, together with a
   820 corresponding virtual machine and a specification of its bytecode
   821 verifier and a lightweight bytecode verifier, including proofs of
   822 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
   823 Cornelia Pusch (see also the homepage of project Bali at
   824 http://isabelle.in.tum.de/Bali/);
   825 
   826 * HOL/Algebra: new theory of rings and univariate polynomials, by
   827 Clemens Ballarin;
   828 
   829 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
   830 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
   831 Rasmussen;
   832 
   833 * HOL/Lattice: fundamental concepts of lattice theory and order
   834 structures, including duals, properties of bounds versus algebraic
   835 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
   836 Theorem for complete lattices etc.; may also serve as a demonstration
   837 for abstract algebraic reasoning using axiomatic type classes, and
   838 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
   839 
   840 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
   841 von Oheimb;
   842 
   843 * HOL/IMPP: extension of IMP with local variables and mutually
   844 recursive procedures, by David von Oheimb;
   845 
   846 * HOL/Lambda: converted into new-style theory and document;
   847 
   848 * HOL/ex/Multiquote: example of multiple nested quotations and
   849 anti-quotations -- basically a generalized version of de-Bruijn
   850 representation; very useful in avoiding lifting of operations;
   851 
   852 * HOL/record: added general record equality rule to simpset; fixed
   853 select-update simplification procedure to handle extended records as
   854 well; admit "r" as field name;
   855 
   856 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
   857 other numeric types and also as the identity of groups, rings, etc.;
   858 
   859 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
   860 Types nat and int belong to this axclass;
   861 
   862 * HOL: greatly improved simplification involving numerals of type nat, int, real:
   863    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
   864    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
   865   two terms #m*u and #n*u are replaced by #(m+n)*u
   866     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
   867   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
   868     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
   869 
   870 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
   871 powerful prover for predicate logic but knows nothing of clasets; see
   872 ex/mesontest.ML and ex/mesontest2.ML for example applications;
   873 
   874 * HOL: new version of "case_tac" subsumes both boolean case split and
   875 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
   876 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
   877 
   878 * HOL: simplification no longer dives into case-expressions: only the
   879 selector expression is simplified, but not the remaining arms; to
   880 enable full simplification of case-expressions for datatype t, you may
   881 remove t.weak_case_cong from the simpset, either globally (Delcongs
   882 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
   883 
   884 * HOL/recdef: the recursion equations generated by 'recdef' for
   885 function 'f' are now called f.simps instead of f.rules; if all
   886 termination conditions are proved automatically, these simplification
   887 rules are added to the simpset, as in primrec; rules may be named
   888 individually as well, resulting in a separate list of theorems for
   889 each equation;
   890 
   891 * HOL/While is a new theory that provides a while-combinator. It
   892 permits the definition of tail-recursive functions without the
   893 provision of a termination measure. The latter is necessary once the
   894 invariant proof rule for while is applied.
   895 
   896 * HOL: new (overloaded) notation for the set of elements below/above
   897 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
   898 
   899 * HOL: theorems impI, allI, ballI bound as "strip";
   900 
   901 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
   902 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
   903 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
   904 
   905 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   906 
   907 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
   908 main HOL, but was unused);
   909 
   910 * HOL: fewer consts declared as global (e.g. have to refer to
   911 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
   912 
   913 * HOL: tuned AST representation of nested pairs, avoiding bogus output
   914 in case of overlap with user translations (e.g. judgements over
   915 tuples); (note that the underlying logical represenation is still
   916 bogus);
   917 
   918 
   919 *** ZF ***
   920 
   921 * ZF: simplification automatically cancels common terms in arithmetic
   922 expressions over nat and int;
   923 
   924 * ZF: new treatment of nat to minimize type-checking: all operators
   925 coerce their operands to a natural number using the function natify,
   926 making the algebraic laws unconditional;
   927 
   928 * ZF: as above, for int: operators coerce their operands to an integer
   929 using the function intify;
   930 
   931 * ZF: the integer library now contains many of the usual laws for the
   932 orderings, including $<=, and monotonicity laws for $+ and $*;
   933 
   934 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
   935 simplification;
   936 
   937 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
   938 to the simplifier and classical reasoner simultaneously;
   939 
   940 
   941 *** General ***
   942 
   943 * Provers: blast_tac now handles actual object-logic rules as
   944 assumptions; note that auto_tac uses blast_tac internally as well;
   945 
   946 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
   947 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
   948 
   949 * Provers: delrules now handles destruct rules as well (no longer need
   950 explicit make_elim);
   951 
   952 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
   953   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   954 use instead the strong form,
   955   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   956 in HOL, FOL and ZF the function cla_make_elim will create such rules
   957 from destruct-rules;
   958 
   959 * Provers: Simplifier.easy_setup provides a fast path to basic
   960 Simplifier setup for new object-logics;
   961 
   962 * Pure: AST translation rules no longer require constant head on LHS;
   963 
   964 * Pure: improved name spaces: ambiguous output is qualified; support
   965 for hiding of names;
   966 
   967 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
   968 XSYMBOL_HOME; no longer need to do manual configuration in most
   969 situations;
   970 
   971 * system: compression of ML heaps images may now be controlled via -c
   972 option of isabelle and isatool usedir (currently only observed by
   973 Poly/ML);
   974 
   975 * system: isatool installfonts may handle X-Symbol fonts as well (very
   976 useful for remote X11);
   977 
   978 * system: provide TAGS file for Isabelle sources;
   979 
   980 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
   981 order;
   982 
   983 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
   984 timing flag supersedes proof_timing and Toplevel.trace;
   985 
   986 * ML: new combinators |>> and |>>> for incremental transformations
   987 with secondary results (e.g. certain theory extensions):
   988 
   989 * ML: PureThy.add_defs gets additional argument to indicate potential
   990 overloading (usually false);
   991 
   992 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
   993 results;
   994 
   995 
   996 
   997 New in Isabelle99 (October 1999)
   998 --------------------------------
   999 
  1000 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1001 
  1002 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  1003 are no longer simplified.  (This allows the simplifier to unfold recursive
  1004 functional programs.)  To restore the old behaviour, declare
  1005 
  1006     Delcongs [if_weak_cong];
  1007 
  1008 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  1009 complement;
  1010 
  1011 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  1012 
  1013 * HOL/datatype: mutual_induct_tac no longer exists --
  1014   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  1015 
  1016 * HOL/typedef: fixed type inference for representing set; type
  1017 arguments now have to occur explicitly on the rhs as type constraints;
  1018 
  1019 * ZF: The con_defs part of an inductive definition may no longer refer
  1020 to constants declared in the same theory;
  1021 
  1022 * HOL, ZF: the function mk_cases, generated by the inductive
  1023 definition package, has lost an argument.  To simplify its result, it
  1024 uses the default simpset instead of a supplied list of theorems.
  1025 
  1026 * HOL/List: the constructors of type list are now Nil and Cons;
  1027 
  1028 * Simplifier: the type of the infix ML functions
  1029         setSSolver addSSolver setSolver addSolver
  1030 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  1031 for packaging solvers. A solver is created via
  1032         mk_solver: string -> (thm list -> int -> tactic) -> solver
  1033 where the string argument is only a comment.
  1034 
  1035 
  1036 *** Proof tools ***
  1037 
  1038 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  1039 decision procedure for linear arithmetic. Currently it is used for
  1040 types `nat', `int', and `real' in HOL (see below); it can, should and
  1041 will be instantiated for other types and logics as well.
  1042 
  1043 * The simplifier now accepts rewrite rules with flexible heads, eg
  1044      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  1045   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  1046   matching.
  1047 
  1048 
  1049 *** General ***
  1050 
  1051 * New Isabelle/Isar subsystem provides an alternative to traditional
  1052 tactical theorem proving; together with the ProofGeneral/isar user
  1053 interface it offers an interactive environment for developing human
  1054 readable proof documents (Isar == Intelligible semi-automated
  1055 reasoning); for further information see isatool doc isar-ref,
  1056 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  1057 
  1058 * improved and simplified presentation of theories: better HTML markup
  1059 (including colors), graph views in several sizes; isatool usedir now
  1060 provides a proper interface for user theories (via -P option); actual
  1061 document preparation based on (PDF)LaTeX is available as well (for
  1062 new-style theories only); see isatool doc system for more information;
  1063 
  1064 * native support for Proof General, both for classic Isabelle and
  1065 Isabelle/Isar;
  1066 
  1067 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  1068 using the graph browser tool;
  1069 
  1070 * Isabelle manuals now also available as PDF;
  1071 
  1072 * theory loader rewritten from scratch (may not be fully
  1073 bug-compatible); old loadpath variable has been replaced by show_path,
  1074 add_path, del_path, reset_path functions; new operations such as
  1075 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  1076 isatool doc ref);
  1077 
  1078 * improved isatool install: option -k creates KDE application icon,
  1079 option -p DIR installs standalone binaries;
  1080 
  1081 * added ML_PLATFORM setting (useful for cross-platform installations);
  1082 more robust handling of platform specific ML images for SML/NJ;
  1083 
  1084 * the settings environment is now statically scoped, i.e. it is never
  1085 created again in sub-processes invoked from isabelle, isatool, or
  1086 Isabelle;
  1087 
  1088 * path element specification '~~' refers to '$ISABELLE_HOME';
  1089 
  1090 * in locales, the "assumes" and "defines" parts may be omitted if
  1091 empty;
  1092 
  1093 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  1094 long arrows);
  1095 
  1096 * new print_mode "HTML";
  1097 
  1098 * new flag show_tags controls display of tags of theorems (which are
  1099 basically just comments that may be attached by some tools);
  1100 
  1101 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  1102 mode and goal output format:
  1103 
  1104 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  1105 244c244
  1106 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  1107 ---
  1108 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  1109 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  1110 181c181
  1111 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  1112 ---
  1113 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  1114 
  1115 * function bind_thms stores lists of theorems (cf. bind_thm);
  1116 
  1117 * new shorthand tactics ftac, eatac, datac, fatac;
  1118 
  1119 * qed (and friends) now accept "" as result name; in that case the
  1120 theorem is not stored, but proper checks and presentation of the
  1121 result still apply;
  1122 
  1123 * theorem database now also indexes constants "Trueprop", "all",
  1124 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  1125 
  1126 
  1127 *** HOL ***
  1128 
  1129 ** HOL arithmetic **
  1130 
  1131 * There are now decision procedures for linear arithmetic over nat and
  1132 int:
  1133 
  1134 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  1135 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  1136 are treated as atomic; subformulae not involving type `nat' or `int'
  1137 are ignored; quantified subformulae are ignored unless they are
  1138 positive universal or negative existential. The tactic has to be
  1139 invoked by hand and can be a little bit slow. In particular, the
  1140 running time is exponential in the number of occurrences of `min' and
  1141 `max', and `-' on `nat'.
  1142 
  1143 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  1144 (negated) (in)equalities among the premises and the conclusion into
  1145 account (i.e. no compound formulae) and does not know about `min' and
  1146 `max', and `-' on `nat'. It is fast and is used automatically by the
  1147 simplifier.
  1148 
  1149 NB: At the moment, these decision procedures do not cope with mixed
  1150 nat/int formulae where the two parts interact, such as `m < n ==>
  1151 int(m) < int(n)'.
  1152 
  1153 * HOL/Numeral provides a generic theory of numerals (encoded
  1154 efficiently as bit strings); setup for types nat/int/real is in place;
  1155 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  1156 int, existing theories and proof scripts may require a few additional
  1157 type constraints;
  1158 
  1159 * integer division and remainder can now be performed on constant
  1160 arguments;
  1161 
  1162 * many properties of integer multiplication, division and remainder
  1163 are now available;
  1164 
  1165 * An interface to the Stanford Validity Checker (SVC) is available through the
  1166 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  1167 are proved automatically.  SVC must be installed separately, and its results
  1168 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  1169 invocation of the underlying oracle).  For SVC see
  1170   http://verify.stanford.edu/SVC
  1171 
  1172 * IsaMakefile: the HOL-Real target now builds an actual image;
  1173 
  1174 
  1175 ** HOL misc **
  1176 
  1177 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  1178 (in Isabelle/Isar) -- by Gertrud Bauer;
  1179 
  1180 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  1181 analysis for assembly languages with subtypes;
  1182 
  1183 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  1184 -- avoids syntactic ambiguities and treats state, transition, and
  1185 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  1186 changed syntax and (many) tactics;
  1187 
  1188 * HOL/inductive: Now also handles more general introduction rules such
  1189   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  1190   theorems are now maintained within the theory (maintained via the
  1191   "mono" attribute);
  1192 
  1193 * HOL/datatype: Now also handles arbitrarily branching datatypes
  1194   (using function types) such as
  1195 
  1196   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  1197 
  1198 * HOL/record: record_simproc (part of the default simpset) takes care
  1199 of selectors applied to updated records; record_split_tac is no longer
  1200 part of the default claset; update_defs may now be removed from the
  1201 simpset in many cases; COMPATIBILITY: old behavior achieved by
  1202 
  1203   claset_ref () := claset() addSWrapper record_split_wrapper;
  1204   Delsimprocs [record_simproc]
  1205 
  1206 * HOL/typedef: fixed type inference for representing set; type
  1207 arguments now have to occur explicitly on the rhs as type constraints;
  1208 
  1209 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  1210 names rather than an ML expression;
  1211 
  1212 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  1213 supplied later.  Program schemes can be defined, such as
  1214     "While B C s = (if B s then While B C (C s) else s)"
  1215 where the well-founded relation can be chosen after B and C have been given.
  1216 
  1217 * HOL/List: the constructors of type list are now Nil and Cons;
  1218 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  1219 course, ML tools referring to List.list.op # etc. have to be adapted;
  1220 
  1221 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  1222 disabled by default; run isabelle with option -m HOL to get back to
  1223 the original Gordon/HOL-style output;
  1224 
  1225 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  1226 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  1227 
  1228 * HOL basic syntax simplified (more orthogonal): all variants of
  1229 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  1230 Eps operator is provided as well: "SOME x. P[x]";
  1231 
  1232 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  1233 
  1234 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  1235 thus available for user theories;
  1236 
  1237 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  1238 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  1239 time;
  1240 
  1241 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  1242 several times and then mp;
  1243 
  1244 
  1245 *** LK ***
  1246 
  1247 * the notation <<...>> is now available as a notation for sequences of
  1248 formulas;
  1249 
  1250 * the simplifier is now installed
  1251 
  1252 * the axiom system has been generalized (thanks to Soren Heilmann)
  1253 
  1254 * the classical reasoner now has a default rule database
  1255 
  1256 
  1257 *** ZF ***
  1258 
  1259 * new primrec section allows primitive recursive functions to be given
  1260 directly (as in HOL) over datatypes and the natural numbers;
  1261 
  1262 * new tactics induct_tac and exhaust_tac for induction (or case
  1263 analysis) over datatypes and the natural numbers;
  1264 
  1265 * the datatype declaration of type T now defines the recursor T_rec;
  1266 
  1267 * simplification automatically does freeness reasoning for datatype
  1268 constructors;
  1269 
  1270 * automatic type-inference, with AddTCs command to insert new
  1271 type-checking rules;
  1272 
  1273 * datatype introduction rules are now added as Safe Introduction rules
  1274 to the claset;
  1275 
  1276 * the syntax "if P then x else y" is now available in addition to
  1277 if(P,x,y);
  1278 
  1279 
  1280 *** Internal programming interfaces ***
  1281 
  1282 * tuned simplifier trace output; new flag debug_simp;
  1283 
  1284 * structures Vartab / Termtab (instances of TableFun) offer efficient
  1285 tables indexed by indexname_ord / term_ord (compatible with aconv);
  1286 
  1287 * AxClass.axclass_tac lost the theory argument;
  1288 
  1289 * tuned current_goals_markers semantics: begin / end goal avoids
  1290 printing empty lines;
  1291 
  1292 * removed prs and prs_fn hook, which was broken because it did not
  1293 include \n in its semantics, forcing writeln to add one
  1294 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  1295 string -> unit if you really want to output text without newline;
  1296 
  1297 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  1298 plain output, interface builders may have to enable 'isabelle_font'
  1299 mode to get Isabelle font glyphs as before;
  1300 
  1301 * refined token_translation interface; INCOMPATIBILITY: output length
  1302 now of type real instead of int;
  1303 
  1304 * theory loader actions may be traced via new ThyInfo.add_hook
  1305 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  1306 your own database of information attached to *whole* theories -- as
  1307 opposed to intra-theory data slots offered via TheoryDataFun;
  1308 
  1309 * proper handling of dangling sort hypotheses (at last!);
  1310 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  1311 extra sort hypotheses that can be witnessed from the type signature;
  1312 the force_strip_shyps flag is gone, any remaining shyps are simply
  1313 left in the theorem (with a warning issued by strip_shyps_warning);
  1314 
  1315 
  1316 
  1317 New in Isabelle98-1 (October 1998)
  1318 ----------------------------------
  1319 
  1320 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1321 
  1322 * several changes of automated proof tools;
  1323 
  1324 * HOL: major changes to the inductive and datatype packages, including
  1325 some minor incompatibilities of theory syntax;
  1326 
  1327 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  1328 called `inj_on';
  1329 
  1330 * HOL: removed duplicate thms in Arith:
  1331   less_imp_add_less  should be replaced by  trans_less_add1
  1332   le_imp_add_le      should be replaced by  trans_le_add1
  1333 
  1334 * HOL: unary minus is now overloaded (new type constraints may be
  1335 required);
  1336 
  1337 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  1338 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  1339 now taken as an integer constant.
  1340 
  1341 * Pure: ML function 'theory_of' renamed to 'theory';
  1342 
  1343 
  1344 *** Proof tools ***
  1345 
  1346 * Simplifier:
  1347   1. Asm_full_simp_tac is now more aggressive.
  1348      1. It will sometimes reorient premises if that increases their power to
  1349         simplify.
  1350      2. It does no longer proceed strictly from left to right but may also
  1351         rotate premises to achieve further simplification.
  1352      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  1353      old Asm_full_simp_tac in that it does not rotate premises.
  1354   2. The simplifier now knows a little bit about nat-arithmetic.
  1355 
  1356 * Classical reasoner: wrapper mechanism for the classical reasoner now
  1357 allows for selected deletion of wrappers, by introduction of names for
  1358 wrapper functionals.  This implies that addbefore, addSbefore,
  1359 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  1360 and that adding two tactics with the same name overwrites the first
  1361 one (emitting a warning).
  1362   type wrapper = (int -> tactic) -> (int -> tactic)
  1363   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  1364   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  1365   delWrapper, delSWrapper: claset *  string            -> claset
  1366   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  1367 
  1368 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  1369 semantics; addbefore now affects only the unsafe part of step_tac
  1370 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  1371 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  1372 by Force_tac;
  1373 
  1374 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  1375 compWrapper; added safe wrapper (and access functions for it);
  1376 
  1377 * HOL/split_all_tac is now much faster and fails if there is nothing
  1378 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  1379 and the names of the automatically generated variables have changed.
  1380 split_all_tac has moved within claset() from unsafe wrappers to safe
  1381 wrappers, which means that !!-bound variables are split much more
  1382 aggressively, and safe_tac and clarify_tac now split such variables.
  1383 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  1384 Note: the same holds for record_split_tac, which does the job of
  1385 split_all_tac for record fields.
  1386 
  1387 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  1388 permanently to the default simpset using Addsplits just like
  1389 Addsimps. They can be removed via Delsplits just like
  1390 Delsimps. Lower-case versions are also available.
  1391 
  1392 * HOL/Simplifier: The rule split_if is now part of the default
  1393 simpset. This means that the simplifier will eliminate all occurrences
  1394 of if-then-else in the conclusion of a goal. To prevent this, you can
  1395 either remove split_if completely from the default simpset by
  1396 `Delsplits [split_if]' or remove it in a specific call of the
  1397 simplifier using `... delsplits [split_if]'.  You can also add/delete
  1398 other case splitting rules to/from the default simpset: every datatype
  1399 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  1400 t is the name of the datatype).
  1401 
  1402 * Classical reasoner / Simplifier combination: new force_tac (and
  1403 derivatives Force_tac, force) combines rewriting and classical
  1404 reasoning (and whatever other tools) similarly to auto_tac, but is
  1405 aimed to solve the given subgoal completely.
  1406 
  1407 
  1408 *** General ***
  1409 
  1410 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  1411 and `goalw': the theory is no longer needed as an explicit argument -
  1412 the current theory context is used; assumptions are no longer returned
  1413 at the ML-level unless one of them starts with ==> or !!; it is
  1414 recommended to convert to these new commands using isatool fixgoal
  1415 (backup your sources first!);
  1416 
  1417 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  1418 the current theory context, and 'theory' to lookup stored theories;
  1419 
  1420 * new theory section 'locale' for declaring constants, assumptions and
  1421 definitions that have local scope;
  1422 
  1423 * new theory section 'nonterminals' for purely syntactic types;
  1424 
  1425 * new theory section 'setup' for generic ML setup functions
  1426 (e.g. package initialization);
  1427 
  1428 * the distribution now includes Isabelle icons: see
  1429 lib/logo/isabelle-{small,tiny}.xpm;
  1430 
  1431 * isatool install - install binaries with absolute references to
  1432 ISABELLE_HOME/bin;
  1433 
  1434 * isatool logo -- create instances of the Isabelle logo (as EPS);
  1435 
  1436 * print mode 'emacs' reserved for Isamode;
  1437 
  1438 * support multiple print (ast) translations per constant name;
  1439 
  1440 * theorems involving oracles are now printed with a suffixed [!];
  1441 
  1442 
  1443 *** HOL ***
  1444 
  1445 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  1446 
  1447 * HOL/inductive package reorganized and improved: now supports mutual
  1448 definitions such as
  1449 
  1450   inductive EVEN ODD
  1451     intrs
  1452       null "0 : EVEN"
  1453       oddI "n : EVEN ==> Suc n : ODD"
  1454       evenI "n : ODD ==> Suc n : EVEN"
  1455 
  1456 new theorem list "elims" contains an elimination rule for each of the
  1457 recursive sets; inductive definitions now handle disjunctive premises
  1458 correctly (also ZF);
  1459 
  1460 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  1461 "mutual_induct" no longer exists - the induction rule is always
  1462 contained in "induct";
  1463 
  1464 
  1465 * HOL/datatype package re-implemented and greatly improved: now
  1466 supports mutually recursive datatypes such as
  1467 
  1468   datatype
  1469     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  1470             | SUM ('a aexp) ('a aexp)
  1471             | DIFF ('a aexp) ('a aexp)
  1472             | NUM 'a
  1473   and
  1474     'a bexp = LESS ('a aexp) ('a aexp)
  1475             | AND ('a bexp) ('a bexp)
  1476             | OR ('a bexp) ('a bexp)
  1477 
  1478 as well as indirectly recursive datatypes such as
  1479 
  1480   datatype
  1481     ('a, 'b) term = Var 'a
  1482                   | App 'b ((('a, 'b) term) list)
  1483 
  1484 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  1485 induction on mutually / indirectly recursive datatypes.
  1486 
  1487 Primrec equations are now stored in theory and can be accessed via
  1488 <function_name>.simps.
  1489 
  1490 INCOMPATIBILITIES:
  1491 
  1492   - Theories using datatypes must now have theory Datatype as an
  1493     ancestor.
  1494   - The specific <typename>.induct_tac no longer exists - use the
  1495     generic induct_tac instead.
  1496   - natE has been renamed to nat.exhaust - use exhaust_tac
  1497     instead of res_inst_tac ... natE. Note that the variable
  1498     names in nat.exhaust differ from the names in natE, this
  1499     may cause some "fragile" proofs to fail.
  1500   - The theorems split_<typename>_case and split_<typename>_case_asm
  1501     have been renamed to <typename>.split and <typename>.split_asm.
  1502   - Since default sorts of type variables are now handled correctly,
  1503     some datatype definitions may have to be annotated with explicit
  1504     sort constraints.
  1505   - Primrec definitions no longer require function name and type
  1506     of recursive argument.
  1507 
  1508 Consider using isatool fixdatatype to adapt your theories and proof
  1509 scripts to the new package (backup your sources first!).
  1510 
  1511 
  1512 * HOL/record package: considerably improved implementation; now
  1513 includes concrete syntax for record types, terms, updates; theorems
  1514 for surjective pairing and splitting !!-bound record variables; proof
  1515 support is as follows:
  1516 
  1517   1) standard conversions (selectors or updates applied to record
  1518 constructor terms) are part of the standard simpset;
  1519 
  1520   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  1521 made part of standard simpset and claset via addIffs;
  1522 
  1523   3) a tactic for record field splitting (record_split_tac) is part of
  1524 the standard claset (addSWrapper);
  1525 
  1526 To get a better idea about these rules you may retrieve them via
  1527 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  1528 the name of your record type.
  1529 
  1530 The split tactic 3) conceptually simplifies by the following rule:
  1531 
  1532   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  1533 
  1534 Thus any record variable that is bound by meta-all will automatically
  1535 blow up into some record constructor term, consequently the
  1536 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  1537 solve record problems automatically.
  1538 
  1539 
  1540 * reorganized the main HOL image: HOL/Integ and String loaded by
  1541 default; theory Main includes everything;
  1542 
  1543 * automatic simplification of integer sums and comparisons, using cancellation;
  1544 
  1545 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  1546 
  1547 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  1548 
  1549 * many new identities for unions, intersections, set difference, etc.;
  1550 
  1551 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  1552 called split_if, split_split, split_sum_case and split_nat_case (to go
  1553 with add/delsplits);
  1554 
  1555 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  1556 (?x::unit) = (); this is made part of the default simpset, which COULD
  1557 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  1558 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  1559 unit_abs_eta_conv is added in order to counter the effect of
  1560 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  1561 %u.f();
  1562 
  1563 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  1564 makes more sense);
  1565 
  1566 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1567   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1568   disjointness reasoning but breaking a few old proofs.
  1569 
  1570 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  1571 to 'converse' from 'inverse' (for compatibility with ZF and some
  1572 literature);
  1573 
  1574 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  1575 the well-founded relation;
  1576 
  1577 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  1578     Compl A.  The "Compl" syntax remains available as input syntax for this
  1579     release ONLY.
  1580 
  1581 * HOL/Update: new theory of function updates:
  1582     f(a:=b) == %x. if x=a then b else f x
  1583 may also be iterated as in f(a:=b,c:=d,...);
  1584 
  1585 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  1586 
  1587 * HOL/List:
  1588   - new function list_update written xs[i:=v] that updates the i-th
  1589     list position. May also be iterated as in xs[i:=a,j:=b,...].
  1590   - new function `upt' written [i..j(] which generates the list
  1591     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  1592     bound write [i..j], which is a shorthand for [i..j+1(].
  1593   - new lexicographic orderings and corresponding wellfoundedness theorems.
  1594 
  1595 * HOL/Arith:
  1596   - removed 'pred' (predecessor) function;
  1597   - generalized some theorems about n-1;
  1598   - many new laws about "div" and "mod";
  1599   - new laws about greatest common divisors (see theory ex/Primes);
  1600 
  1601 * HOL/Relation: renamed the relational operator r^-1 "converse"
  1602 instead of "inverse";
  1603 
  1604 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  1605   of the multiset ordering;
  1606 
  1607 * directory HOL/Real: a construction of the reals using Dedekind cuts
  1608   (not included by default);
  1609 
  1610 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  1611 
  1612 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  1613   programs, i.e. different program variables may have different types.
  1614 
  1615 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1616   [previously, this check worked only if the rewrite rule was unconditional]
  1617   Now rew can involve either definitions or equalities (either == or =).
  1618 
  1619 
  1620 *** ZF ***
  1621 
  1622 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  1623   only the theorems proved on ZF.ML;
  1624 
  1625 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1626   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1627   disjointness reasoning but breaking a few old proofs.
  1628 
  1629 * ZF/Update: new theory of function updates
  1630     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  1631   may also be iterated as in f(a:=b,c:=d,...);
  1632 
  1633 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  1634 
  1635 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1636   [previously, this check worked only if the rewrite rule was unconditional]
  1637   Now rew can involve either definitions or equalities (either == or =).
  1638 
  1639 * case_tac provided for compatibility with HOL
  1640     (like the old excluded_middle_tac, but with subgoals swapped)
  1641 
  1642 
  1643 *** Internal programming interfaces ***
  1644 
  1645 * Pure: several new basic modules made available for general use, see
  1646 also src/Pure/README;
  1647 
  1648 * improved the theory data mechanism to support encapsulation (data
  1649 kind name replaced by private Object.kind, acting as authorization
  1650 key); new type-safe user interface via functor TheoryDataFun; generic
  1651 print_data function becomes basically useless;
  1652 
  1653 * removed global_names compatibility flag -- all theory declarations
  1654 are qualified by default;
  1655 
  1656 * module Pure/Syntax now offers quote / antiquote translation
  1657 functions (useful for Hoare logic etc. with implicit dependencies);
  1658 see HOL/ex/Antiquote for an example use;
  1659 
  1660 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  1661 cterm -> thm;
  1662 
  1663 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  1664 subgoal;
  1665 
  1666 * Display.print_goals function moved to Locale.print_goals;
  1667 
  1668 * standard print function for goals supports current_goals_markers
  1669 variable for marking begin of proof, end of proof, start of goal; the
  1670 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  1671 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  1672 for example;
  1673 
  1674 
  1675 
  1676 New in Isabelle98 (January 1998)
  1677 --------------------------------
  1678 
  1679 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1680 
  1681 * changed lexical syntax of terms / types: dots made part of long
  1682 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  1683 
  1684 * simpset (and claset) reference variable replaced by functions
  1685 simpset / simpset_ref;
  1686 
  1687 * no longer supports theory aliases (via merge) and non-trivial
  1688 implicit merge of thms' signatures;
  1689 
  1690 * most internal names of constants changed due to qualified names;
  1691 
  1692 * changed Pure/Sequence interface (see Pure/seq.ML);
  1693 
  1694 
  1695 *** General Changes ***
  1696 
  1697 * hierachically structured name spaces (for consts, types, axms, thms
  1698 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  1699 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  1700 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  1701 long_names for fully qualified output names; NOTE: ML programs
  1702 (special tactics, packages etc.) referring to internal names may have
  1703 to be adapted to cope with fully qualified names; in case of severe
  1704 backward campatibility problems try setting 'global_names' at compile
  1705 time to have enrything declared within a flat name space; one may also
  1706 fine tune name declarations in theories via the 'global' and 'local'
  1707 section;
  1708 
  1709 * reimplemented the implicit simpset and claset using the new anytype
  1710 data filed in signatures; references simpset:simpset ref etc. are
  1711 replaced by functions simpset:unit->simpset and
  1712 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  1713 to patch your ML files accordingly;
  1714 
  1715 * HTML output now includes theory graph data for display with Java
  1716 applet or isatool browser; data generated automatically via isatool
  1717 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  1718 
  1719 * defs may now be conditional; improved rewrite_goals_tac to handle
  1720 conditional equations;
  1721 
  1722 * defs now admits additional type arguments, using TYPE('a) syntax;
  1723 
  1724 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  1725 creates a new theory node; implicit merge of thms' signatures is
  1726 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  1727 transfer:theory->thm->thm in (rare) cases;
  1728 
  1729 * improved handling of draft signatures / theories; draft thms (and
  1730 ctyps, cterms) are automatically promoted to real ones;
  1731 
  1732 * slightly changed interfaces for oracles: admit many per theory, named
  1733 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  1734 
  1735 * print_goals: optional output of const types (set show_consts and
  1736 show_types);
  1737 
  1738 * improved output of warnings (###) and errors (***);
  1739 
  1740 * subgoal_tac displays a warning if the new subgoal has type variables;
  1741 
  1742 * removed old README and Makefiles;
  1743 
  1744 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  1745 
  1746 * removed obsolete init_pps and init_database;
  1747 
  1748 * deleted the obsolete tactical STATE, which was declared by
  1749     fun STATE tacfun st = tacfun st st;
  1750 
  1751 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  1752 (which abbreviates $HOME);
  1753 
  1754 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  1755 use isatool fixseq to adapt your ML programs (this works for fully
  1756 qualified references to the Sequence structure only!);
  1757 
  1758 * use_thy no longer requires writable current directory; it always
  1759 reloads .ML *and* .thy file, if either one is out of date;
  1760 
  1761 
  1762 *** Classical Reasoner ***
  1763 
  1764 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  1765 tactics that use classical reasoning to simplify a subgoal without
  1766 splitting it into several subgoals;
  1767 
  1768 * Safe_tac: like safe_tac but uses the default claset;
  1769 
  1770 
  1771 *** Simplifier ***
  1772 
  1773 * added simplification meta rules:
  1774     (asm_)(full_)simplify: simpset -> thm -> thm;
  1775 
  1776 * simplifier.ML no longer part of Pure -- has to be loaded by object
  1777 logics (again);
  1778 
  1779 * added prems argument to simplification procedures;
  1780 
  1781 * HOL, FOL, ZF: added infix function `addsplits':
  1782   instead of `<simpset> setloop (split_tac <thms>)'
  1783   you can simply write `<simpset> addsplits <thms>'
  1784 
  1785 
  1786 *** Syntax ***
  1787 
  1788 * TYPE('a) syntax for type reflection terms;
  1789 
  1790 * no longer handles consts with name "" -- declare as 'syntax' instead;
  1791 
  1792 * pretty printer: changed order of mixfix annotation preference (again!);
  1793 
  1794 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  1795 
  1796 
  1797 *** HOL ***
  1798 
  1799 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1800   with `addloop' of the simplifier to faciliate case splitting in premises.
  1801 
  1802 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  1803 
  1804 * HOL/Auth: new protocol proofs including some for the Internet
  1805   protocol TLS;
  1806 
  1807 * HOL/Map: new theory of `maps' a la VDM;
  1808 
  1809 * HOL/simplifier: simplification procedures nat_cancel_sums for
  1810 cancelling out common nat summands from =, <, <= (in)equalities, or
  1811 differences; simplification procedures nat_cancel_factor for
  1812 cancelling common factor from =, <, <= (in)equalities over natural
  1813 sums; nat_cancel contains both kinds of procedures, it is installed by
  1814 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  1815 
  1816 * HOL/simplifier: terms of the form
  1817   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  1818   are rewritten to
  1819   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  1820   and those of the form
  1821   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  1822   are rewritten to
  1823   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  1824 
  1825 * HOL/datatype
  1826   Each datatype `t' now comes with a theorem `split_t_case' of the form
  1827 
  1828   P(t_case f1 ... fn x) =
  1829      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  1830         ...
  1831        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  1832      )
  1833 
  1834   and a theorem `split_t_case_asm' of the form
  1835 
  1836   P(t_case f1 ... fn x) =
  1837     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  1838         ...
  1839        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  1840      )
  1841   which can be added to a simpset via `addsplits'. The existing theorems
  1842   expand_list_case and expand_option_case have been renamed to
  1843   split_list_case and split_option_case.
  1844 
  1845 * HOL/Arithmetic:
  1846   - `pred n' is automatically converted to `n-1'.
  1847     Users are strongly encouraged not to use `pred' any longer,
  1848     because it will disappear altogether at some point.
  1849   - Users are strongly encouraged to write "0 < n" rather than
  1850     "n ~= 0". Theorems and proof tools have been modified towards this
  1851     `standard'.
  1852 
  1853 * HOL/Lists:
  1854   the function "set_of_list" has been renamed "set" (and its theorems too);
  1855   the function "nth" now takes its arguments in the reverse order and
  1856   has acquired the infix notation "!" as in "xs!n".
  1857 
  1858 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  1859 
  1860 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  1861   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  1862 
  1863 * HOL/record: extensible records with schematic structural subtyping
  1864 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  1865 still lacks various theorems and concrete record syntax;
  1866 
  1867 
  1868 *** HOLCF ***
  1869 
  1870 * removed "axioms" and "generated by" sections;
  1871 
  1872 * replaced "ops" section by extended "consts" section, which is capable of
  1873   handling the continuous function space "->" directly;
  1874 
  1875 * domain package:
  1876   . proves theorems immediately and stores them in the theory,
  1877   . creates hierachical name space,
  1878   . now uses normal mixfix annotations (instead of cinfix...),
  1879   . minor changes to some names and values (for consistency),
  1880   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  1881   . separator between mutual domain defs: changed "," to "and",
  1882   . improved handling of sort constraints;  now they have to
  1883     appear on the left-hand side of the equations only;
  1884 
  1885 * fixed LAM <x,y,zs>.b syntax;
  1886 
  1887 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  1888 adm (%x. P (t x)), where P is chainfinite and t continuous;
  1889 
  1890 
  1891 *** FOL and ZF ***
  1892 
  1893 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1894   with `addloop' of the simplifier to faciliate case splitting in premises.
  1895 
  1896 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  1897 in HOL, they strip ALL and --> from proved theorems;
  1898 
  1899 
  1900 
  1901 New in Isabelle94-8 (May 1997)
  1902 ------------------------------
  1903 
  1904 *** General Changes ***
  1905 
  1906 * new utilities to build / run / maintain Isabelle etc. (in parts
  1907 still somewhat experimental); old Makefiles etc. still functional;
  1908 
  1909 * new 'Isabelle System Manual';
  1910 
  1911 * INSTALL text, together with ./configure and ./build scripts;
  1912 
  1913 * reimplemented type inference for greater efficiency, better error
  1914 messages and clean internal interface;
  1915 
  1916 * prlim command for dealing with lots of subgoals (an easier way of
  1917 setting goals_limit);
  1918 
  1919 
  1920 *** Syntax ***
  1921 
  1922 * supports alternative (named) syntax tables (parser and pretty
  1923 printer); internal interface is provided by add_modesyntax(_i);
  1924 
  1925 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  1926 be used in conjunction with the Isabelle symbol font; uses the
  1927 "symbols" syntax table;
  1928 
  1929 * added token_translation interface (may translate name tokens in
  1930 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  1931 the current print_mode); IMPORTANT: user print translation functions
  1932 are responsible for marking newly introduced bounds
  1933 (Syntax.mark_boundT);
  1934 
  1935 * token translations for modes "xterm" and "xterm_color" that display
  1936 names in bold, underline etc. or colors (which requires a color
  1937 version of xterm);
  1938 
  1939 * infixes may now be declared with names independent of their syntax;
  1940 
  1941 * added typed_print_translation (like print_translation, but may
  1942 access type of constant);
  1943 
  1944 
  1945 *** Classical Reasoner ***
  1946 
  1947 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  1948 some limitations.  Blast_tac...
  1949   + ignores addss, addbefore, addafter; this restriction is intrinsic
  1950   + ignores elimination rules that don't have the correct format
  1951         (the conclusion MUST be a formula variable)
  1952   + ignores types, which can make HOL proofs fail
  1953   + rules must not require higher-order unification, e.g. apply_type in ZF
  1954     [message "Function Var's argument not a bound variable" relates to this]
  1955   + its proof strategy is more general but can actually be slower
  1956 
  1957 * substitution with equality assumptions no longer permutes other
  1958 assumptions;
  1959 
  1960 * minor changes in semantics of addafter (now called addaltern); renamed
  1961 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  1962 (and access functions for it);
  1963 
  1964 * improved combination of classical reasoner and simplifier:
  1965   + functions for handling clasimpsets
  1966   + improvement of addss: now the simplifier is called _after_ the
  1967     safe steps.
  1968   + safe variant of addss called addSss: uses safe simplifications
  1969     _during_ the safe steps. It is more complete as it allows multiple
  1970     instantiations of unknowns (e.g. with slow_tac).
  1971 
  1972 *** Simplifier ***
  1973 
  1974 * added interface for simplification procedures (functions that
  1975 produce *proven* rewrite rules on the fly, depending on current
  1976 redex);
  1977 
  1978 * ordering on terms as parameter (used for ordered rewriting);
  1979 
  1980 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  1981 
  1982 * the solver is now split into a safe and an unsafe part.
  1983 This should be invisible for the normal user, except that the
  1984 functions setsolver and addsolver have been renamed to setSolver and
  1985 addSolver; added safe_asm_full_simp_tac;
  1986 
  1987 
  1988 *** HOL ***
  1989 
  1990 * a generic induction tactic `induct_tac' which works for all datatypes and
  1991 also for type `nat';
  1992 
  1993 * a generic case distinction tactic `exhaust_tac' which works for all
  1994 datatypes and also for type `nat';
  1995 
  1996 * each datatype comes with a function `size';
  1997 
  1998 * patterns in case expressions allow tuple patterns as arguments to
  1999 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  2000 
  2001 * primrec now also works with type nat;
  2002 
  2003 * recdef: a new declaration form, allows general recursive functions to be
  2004 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  2005 
  2006 * the constant for negation has been renamed from "not" to "Not" to
  2007 harmonize with FOL, ZF, LK, etc.;
  2008 
  2009 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  2010 infinite lists;
  2011 
  2012 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  2013 
  2014 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  2015 problems in commutative rings, using axiomatic type classes for + and *;
  2016 
  2017 * more examples in HOL/MiniML and HOL/Auth;
  2018 
  2019 * more default rewrite rules for quantifiers, union/intersection;
  2020 
  2021 * a new constant `arbitrary == @x.False';
  2022 
  2023 * HOLCF/IOA replaces old HOL/IOA;
  2024 
  2025 * HOLCF changes: derived all rules and arities
  2026   + axiomatic type classes instead of classes
  2027   + typedef instead of faking type definitions
  2028   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  2029   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  2030   + eliminated the types void, one, tr
  2031   + use unit lift and bool lift (with translations) instead of one and tr
  2032   + eliminated blift from Lift3.thy (use Def instead of blift)
  2033   all eliminated rules are derived as theorems --> no visible changes ;
  2034 
  2035 
  2036 *** ZF ***
  2037 
  2038 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  2039 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  2040 as ZF_cs addSIs [equalityI];
  2041 
  2042 
  2043 
  2044 New in Isabelle94-7 (November 96)
  2045 ---------------------------------
  2046 
  2047 * allowing negative levels (as offsets) in prlev and choplev;
  2048 
  2049 * super-linear speedup for large simplifications;
  2050 
  2051 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  2052 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  2053 FAIL); can suppress it using the command Delsimps (ex_simps @
  2054 all_simps); De Morgan laws are also now included, by default;
  2055 
  2056 * improved printing of ==>  :  ~:
  2057 
  2058 * new object-logic "Sequents" adds linear logic, while replacing LK
  2059 and Modal (thanks to Sara Kalvala);
  2060 
  2061 * HOL/Auth: correctness proofs for authentication protocols;
  2062 
  2063 * HOL: new auto_tac combines rewriting and classical reasoning (many
  2064 examples on HOL/Auth);
  2065 
  2066 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  2067 the rewriter and classical reasoner simultaneously;
  2068 
  2069 * function uresult no longer returns theorems in "standard" format;
  2070 regain previous version by: val uresult = standard o uresult;
  2071 
  2072 
  2073 
  2074 New in Isabelle94-6
  2075 -------------------
  2076 
  2077 * oracles -- these establish an interface between Isabelle and trusted
  2078 external reasoners, which may deliver results as theorems;
  2079 
  2080 * proof objects (in particular record all uses of oracles);
  2081 
  2082 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  2083 
  2084 * "constdefs" section in theory files;
  2085 
  2086 * "primrec" section (HOL) no longer requires names;
  2087 
  2088 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  2089 
  2090 
  2091 
  2092 New in Isabelle94-5
  2093 -------------------
  2094 
  2095 * reduced space requirements;
  2096 
  2097 * automatic HTML generation from theories;
  2098 
  2099 * theory files no longer require "..." (quotes) around most types;
  2100 
  2101 * new examples, including two proofs of the Church-Rosser theorem;
  2102 
  2103 * non-curried (1994) version of HOL is no longer distributed;
  2104 
  2105 
  2106 
  2107 New in Isabelle94-4
  2108 -------------------
  2109 
  2110 * greatly reduced space requirements;
  2111 
  2112 * theory files (.thy) no longer require \...\ escapes at line breaks;
  2113 
  2114 * searchable theorem database (see the section "Retrieving theorems" on
  2115 page 8 of the Reference Manual);
  2116 
  2117 * new examples, including Grabczewski's monumental case study of the
  2118 Axiom of Choice;
  2119 
  2120 * The previous version of HOL renamed to Old_HOL;
  2121 
  2122 * The new version of HOL (previously called CHOL) uses a curried syntax
  2123 for functions.  Application looks like f a b instead of f(a,b);
  2124 
  2125 * Mutually recursive inductive definitions finally work in HOL;
  2126 
  2127 * In ZF, pattern-matching on tuples is now available in all abstractions and
  2128 translates to the operator "split";
  2129 
  2130 
  2131 
  2132 New in Isabelle94-3
  2133 -------------------
  2134 
  2135 * new infix operator, addss, allowing the classical reasoner to
  2136 perform simplification at each step of its search.  Example:
  2137         fast_tac (cs addss ss)
  2138 
  2139 * a new logic, CHOL, the same as HOL, but with a curried syntax
  2140 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  2141 look like (a,b) instead of <a,b>;
  2142 
  2143 * PLEASE NOTE: CHOL will eventually replace HOL!
  2144 
  2145 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  2146 It translates to the operator "split".  A new theory of integers is available;
  2147 
  2148 * In ZF, integer numerals now denote two's-complement binary integers.
  2149 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  2150 
  2151 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  2152 of the Axiom of Choice;
  2153 
  2154 
  2155 
  2156 New in Isabelle94-2
  2157 -------------------
  2158 
  2159 * Significantly faster resolution;
  2160 
  2161 * the different sections in a .thy file can now be mixed and repeated
  2162 freely;
  2163 
  2164 * Database of theorems for FOL, HOL and ZF.  New
  2165 commands including qed, qed_goal and bind_thm store theorems in the database.
  2166 
  2167 * Simple database queries: return a named theorem (get_thm) or all theorems of
  2168 a given theory (thms_of), or find out what theory a theorem was proved in
  2169 (theory_of_thm);
  2170 
  2171 * Bugs fixed in the inductive definition and datatype packages;
  2172 
  2173 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  2174 and HOL_dup_cs obsolete;
  2175 
  2176 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  2177 have been removed;
  2178 
  2179 * Simpler definition of function space in ZF;
  2180 
  2181 * new results about cardinal and ordinal arithmetic in ZF;
  2182 
  2183 * 'subtype' facility in HOL for introducing new types as subsets of existing
  2184 types;
  2185 
  2186 
  2187 $Id$