NEWS
author nipkow
Thu Feb 14 12:24:02 2002 +0100 (2002-02-14)
changeset 12889 1de4f0b824a8
parent 12877 b9635eb8a448
child 12899 7d5b690253ee
permissions -rw-r--r--
*** empty log message ***
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in Isabelle2002 (January 2002)
     5 ----------------------------------
     6 
     7 *** Document preparation ***
     8 
     9 * greatly simplified document preparation setup, including more
    10 graceful interpretation of isatool usedir -i/-d/-D options, and more
    11 instructive isatool mkdir; users should basically be able to get
    12 started with "isatool mkdir Test && isatool make";
    13 
    14 * theory dependency graph may now be incorporated into documents;
    15 isatool usedir -g true will produce session_graph.eps/.pdf for use
    16 with \includegraphics of LaTeX;
    17 
    18 * proper spacing of consecutive markup elements, especially text
    19 blocks after section headings;
    20 
    21 * support bold style (for single symbols only), input syntax is like
    22 this: "\<^bold>\<alpha>" or "\<^bold>A";
    23 
    24 * \<bullet> is now output as bold \cdot by default, which looks much
    25 better in printed text;
    26 
    27 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
    28 note that these symbols are currently unavailable in Proof General /
    29 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
    30 
    31 * isatool latex no longer depends on changed TEXINPUTS, instead
    32 isatool document copies the Isabelle style files to the target
    33 location;
    34 
    35 
    36 *** Isar ***
    37 
    38 * Pure/Provers: improved proof by cases and induction;
    39   - 'case' command admits impromptu naming of parameters (such as
    40     "case (Suc n)");
    41   - 'induct' method divinates rule instantiation from the inductive
    42     claim; no longer requires excessive ?P bindings for proper
    43     instantiation of cases;
    44   - 'induct' method properly enumerates all possibilities of set/type
    45     rules; as a consequence facts may be also passed through *type*
    46     rules without further ado;
    47   - 'induct' method now derives symbolic cases from the *rulified*
    48     rule (before it used to rulify cases stemming from the internal
    49     atomized version); this means that the context of a non-atomic
    50     statement becomes is included in the hypothesis, avoiding the
    51     slightly cumbersome show "PROP ?case" form;
    52   - 'induct' may now use elim-style induction rules without chaining
    53     facts, using ``missing'' premises from the goal state; this allows
    54     rules stemming from inductive sets to be applied in unstructured
    55     scripts, while still benefitting from proper handling of non-atomic
    56     statements; NB: major inductive premises need to be put first, all
    57     the rest of the goal is passed through the induction;
    58   - 'induct' proper support for mutual induction involving non-atomic
    59     rule statements (uses the new concept of simultaneous goals, see
    60     below);
    61   - append all possible rule selections, but only use the first
    62     success (no backtracking);
    63   - removed obsolete "(simplified)" and "(stripped)" options of methods;
    64   - undeclared rule case names default to numbers 1, 2, 3, ...;
    65   - added 'print_induct_rules' (covered by help item in recent Proof
    66     General versions);
    67   - moved induct/cases attributes to Pure, methods to Provers;
    68   - generic method setup instantiated for FOL and HOL;
    69 
    70 * Pure: support multiple simultaneous goal statements, for example
    71 "have a: A and b: B" (same for 'theorem' etc.); being a pure
    72 meta-level mechanism, this acts as if several individual goals had
    73 been stated separately; in particular common proof methods need to be
    74 repeated in order to cover all claims; note that a single elimination
    75 step is *not* sufficient to establish the two conjunctions, so this
    76 fails:
    77 
    78   assume "A & B" then have A and B ..   (*".." fails*)
    79 
    80 better use "obtain" in situations as above; alternative refer to
    81 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
    82 
    83 * Pure: proper integration with ``locales''; unlike the original
    84 version by Florian Kammüller, Isar locales package high-level proof
    85 contexts rather than raw logical ones (e.g. we admit to include
    86 attributes everywhere); operations on locales include merge and
    87 rename; e.g. see HOL/ex/Locales.thy;
    88 
    89 * Pure: the following commands have been ``localized'', supporting a
    90 target locale specification "(in name)": 'lemma', 'theorem',
    91 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
    92 stored both within the locale and at the theory level (exported and
    93 qualified by the locale name);
    94 
    95 * Pure: theory goals now support ad-hoc contexts, which are discharged
    96 in the result, as in ``lemma (assumes A and B) K: A .''; syntax
    97 coincides with that of a locale body;
    98 
    99 * Pure: renamed "antecedent" case to "rule_context";
   100 
   101 * Pure: added 'corollary' command;
   102 
   103 * Pure: fixed 'token_translation' command;
   104 
   105 * Pure: removed obsolete 'exported' attribute;
   106 
   107 * Pure: dummy pattern "_" in is/let is now automatically lifted over
   108 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
   109 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
   110 
   111 * Pure: method 'atomize' presents local goal premises as object-level
   112 statements (atomic meta-level propositions); setup controlled via
   113 rewrite rules declarations of 'atomize' attribute; example
   114 application: 'induct' method with proper rule statements in improper
   115 proof *scripts*;
   116 
   117 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
   118 now consider the syntactic context of assumptions, giving a better
   119 chance to get type-inference of the arguments right (this is
   120 especially important for locales);
   121 
   122 * Pure: "sorry" no longer requires quick_and_dirty in interactive
   123 mode;
   124 
   125 * Pure/obtain: the formal conclusion "thesis", being marked as
   126 ``internal'', may no longer be reference directly in the text;
   127 potential INCOMPATIBILITY, may need to use "?thesis" in rare
   128 situations;
   129 
   130 * Pure: generic 'sym' attribute which declares a rule both as pure
   131 'elim?' and for the 'symmetric' operation;
   132 
   133 * Pure: marginal comments ``--'' may now occur just anywhere in the
   134 text; the fixed correlation with particular command syntax has been
   135 discontinued;
   136 
   137 * Pure/Provers/classical: simplified integration with pure rule
   138 attributes and methods; the classical "intro?/elim?/dest?"
   139 declarations coincide with the pure ones; the "rule" method no longer
   140 includes classically swapped intros; "intro" and "elim" methods no
   141 longer pick rules from the context; also got rid of ML declarations
   142 AddXIs/AddXEs/AddXDs; all of this has some potential for
   143 INCOMPATIBILITY;
   144 
   145 * Provers/classical: attribute 'swapped' produces classical inversions
   146 of introduction rules;
   147 
   148 * Provers/simplifier: 'simplified' attribute may refer to explicit
   149 rules instead of full simplifier context; 'iff' attribute handles
   150 conditional rules;
   151 
   152 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
   153 
   154 * HOL: 'recdef' now fails on unfinished automated proofs, use
   155 "(permissive)" option to recover old behavior;
   156 
   157 * HOL: 'inductive' no longer features separate (collective) attributes
   158 for 'intros' (was found too confusing);
   159 
   160 * HOL: properly declared induction rules less_induct and
   161 wf_induct_rule;
   162 
   163 
   164 *** HOL ***
   165 
   166 * HOL: moved over to sane numeral syntax; the new policy is as
   167 follows:
   168 
   169   - 0 and 1 are polymorphic constants, which are defined on any
   170   numeric type (nat, int, real etc.);
   171 
   172   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
   173   binary representation internally;
   174 
   175   - type nat has special constructor Suc, and generally prefers Suc 0
   176   over 1::nat and Suc (Suc 0) over 2::nat;
   177 
   178 This change may cause significant problems of INCOMPATIBILITY; here
   179 are some hints on converting existing sources:
   180 
   181   - due to the new "num" token, "-0" and "-1" etc. are now atomic
   182   entities, so expressions involving "-" (unary or binary minus) need
   183   to be spaced properly;
   184 
   185   - existing occurrences of "1" may need to be constraint "1::nat" or
   186   even replaced by Suc 0; similar for old "2";
   187 
   188   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
   189 
   190   - remove all special provisions on numerals in proofs;
   191 
   192 * HOL: simp rules nat_number_of expand numerals on nat to Suc/0
   193 representation (depends on bin_arith_simps in the default context);
   194 
   195 * HOL: symbolic syntax for x^2 (numeral 2);
   196 
   197 * HOL: the class of all HOL types is now called "type" rather than
   198 "term"; INCOMPATIBILITY, need to adapt references to this type class
   199 in axclass/classes, instance/arities, and (usually rare) occurrences
   200 in typings (of consts etc.); internally the class is called
   201 "HOL.type", ML programs should refer to HOLogic.typeS;
   202 
   203 * HOL/record package improvements:
   204   - new derived operations "fields" to build a partial record section,
   205     "extend" to promote a fixed record to a record scheme, and
   206     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
   207     declared as simp by default;
   208   - shared operations ("more", "fields", etc.) now need to be always
   209     qualified) --- potential INCOMPATIBILITY;
   210   - removed "make_scheme" operations (use "make" with "extend") --
   211     INCOMPATIBILITY;
   212   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
   213   - provides cases/induct rules for use with corresponding Isar
   214     methods (for concrete records, record schemes, concrete more
   215     parts, and schematic more parts -- in that order);
   216   - internal definitions directly based on a light-weight abstract
   217     theory of product types over typedef rather than datatype;
   218 
   219 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
   220 
   221 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
   222 (beware of argument permutation!);
   223 
   224 * HOL: linorder_less_split superseded by linorder_cases;
   225 
   226 * HOL/List: "nodups" renamed to "distinct"
   227 
   228 * HOL: added "The" definite description operator; move Hilbert's "Eps"
   229 to peripheral theory "Hilbert_Choice";
   230 
   231 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
   232 in this (rare) case use:
   233 
   234   delSWrapper "split_all_tac"
   235   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
   236 
   237 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
   238 MAY FAIL;
   239 
   240 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
   241 Isabelle's type classes, ^ on functions and relations has too general
   242 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
   243 necessary to attach explicit type constraints;
   244 
   245 * HOL/Relation: the prefix name of the infix "O" has been changed from "comp"
   246 to "rel_comp"; INCOMPATIBILITY: a few theorems have been renamed accordingly
   247 (eg "compI" -> "rel_compI").
   248 
   249 * HOL: syntax translations now work properly with numerals and records
   250 expressions;
   251 
   252 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
   253 of "lam" -- INCOMPATIBILITY;
   254 
   255 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
   256 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
   257 renamed "Product_Type.unit";
   258 
   259 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
   260 
   261 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
   262 Florian Kammüller);
   263 
   264 * HOL/IMP: updated and converted to new-style theory format; several
   265 parts turned into readable document, with proper Isar proof texts and
   266 some explanations (by Gerwin Klein);
   267 
   268 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
   269 
   270 * HOL-Hyperreal is now a logic image;
   271 
   272 
   273 *** HOLCF ***
   274 
   275 * Isar: consts/constdefs supports mixfix syntax for continuous
   276 operations;
   277 
   278 * Isar: domain package adapted to new-style theory format, e.g. see
   279 HOLCF/ex/Dnat.thy;
   280 
   281 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
   282 potential INCOMPATIBILITY; now use plain induct_tac instead of former
   283 lift.induct_tac, always use UU instead of Undef;
   284 
   285 * HOLCF/IMP: updated and converted to new-style theory;
   286 
   287 
   288 *** ZF ***
   289 
   290 * Isar: proper integration of logic-specific tools and packages,
   291 including theory commands '(co)inductive', '(co)datatype',
   292 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
   293 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
   294 
   295 * theory Main no longer includes AC; for the Axiom of Choice, base
   296 your theory on Main_ZFC;
   297 
   298 * the integer library now covers quotients and remainders, with many
   299 laws relating division to addition, multiplication, etc.;
   300 
   301 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
   302 typeless version of the formalism;
   303 
   304 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory format;
   305 
   306 * ZF/Induct: new directory for examples of inductive definitions,
   307 including theory Multiset for multiset orderings; converted to
   308 new-style theory format;
   309 
   310 * Many new theorems about lists, ordinals, etc.;
   311 
   312 
   313 *** General ***
   314 
   315 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
   316 variable proof controls level of detail: 0 = no proofs (only oracle
   317 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
   318 also ref manual for further ML interfaces;
   319 
   320 * Pure/axclass: removed obsolete ML interface
   321 goal_subclass/goal_arity;
   322 
   323 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
   324 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
   325 separate tokens, so expressions involving minus need to be spaced
   326 properly;
   327 
   328 * Pure/syntax: support non-oriented infixes, using keyword "infix"
   329 rather than "infixl" or "infixr";
   330 
   331 * Pure/syntax: concrete syntax for dummy type variables admits genuine
   332 sort constraint specifications in type inference; e.g. "x::_::foo"
   333 ensures that the type of "x" is of sort "foo" (but not necessarily a
   334 type variable);
   335 
   336 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
   337 control output of nested => (types); the default behavior is
   338 "type_brackets";
   339 
   340 * Pure/syntax: builtin parse translation for "_constify" turns valued
   341 tokens into AST constants;
   342 
   343 * Pure/syntax: prefer later declarations of translations and print
   344 translation functions; potential INCOMPATIBILITY: need to reverse
   345 multiple declarations for same syntax element constant;
   346 
   347 * Pure/show_hyps reset by default (in accordance to existing Isar
   348 practice);
   349 
   350 * Provers/classical: renamed addaltern to addafter, addSaltern to
   351 addSafter;
   352 
   353 * Provers/clasimp: ``iff'' declarations now handle conditional rules
   354 as well;
   355 
   356 * system: tested support for MacOS X; should be able to get Isabelle +
   357 Proof General to work in a plain Terminal after installing Poly/ML
   358 (e.g. from the Isabelle distribution area) and GNU bash alone
   359 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
   360 support requires further installations, e.g. from
   361 http://fink.sourceforge.net/);
   362 
   363 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
   364 
   365 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
   366 of 40 MB), cf. ML_OPTIONS;
   367 
   368 * system: Proof General keywords specification is now part of the
   369 Isabelle distribution (see etc/isar-keywords.el);
   370 
   371 * system: support for persistent Proof General sessions (refrain from
   372 outdating all loaded theories on startup); user may create writable
   373 logic images like this: ``isabelle -q HOL Test'';
   374 
   375 * system: smart selection of Isabelle process versus Isabelle
   376 interface, accommodates case-insensitive file systems (e.g. HFS+); may
   377 run both "isabelle" and "Isabelle" even if file names are badly
   378 damaged (executable inspects the case of the first letter of its own
   379 name); added separate "isabelle-process" and "isabelle-interface";
   380 
   381 * system: refrain from any attempt at filtering input streams; no
   382 longer support ``8bit'' encoding of old isabelle font, instead proper
   383 iso-latin characters may now be used; the related isatools
   384 "symbolinput" and "nonascii" have disappeared as well;
   385 
   386 * system: removed old "xterm" interface (the print modes "xterm" and
   387 "xterm_color" are still available for direct use in a suitable
   388 terminal);
   389 
   390 
   391 
   392 New in Isabelle99-2 (February 2001)
   393 -----------------------------------
   394 
   395 *** Overview of INCOMPATIBILITIES ***
   396 
   397 * HOL: please note that theories in the Library and elsewhere often use the
   398 new-style (Isar) format; to refer to their theorems in an ML script you must
   399 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
   400 
   401 * HOL: inductive package no longer splits induction rule aggressively,
   402 but only as far as specified by the introductions given; the old
   403 format may be recovered via ML function complete_split_rule or attribute
   404 'split_rule (complete)';
   405 
   406 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
   407 gfp_Tarski to gfp_unfold;
   408 
   409 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
   410 
   411 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
   412 relation); infix "^^" has been renamed "``"; infix "``" has been
   413 renamed "`"; "univalent" has been renamed "single_valued";
   414 
   415 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
   416 operation;
   417 
   418 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
   419 
   420 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
   421 
   422 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
   423 consequence, it is no longer monotonic wrt. the local goal context
   424 (which is now passed through the inductive cases);
   425 
   426 * Document preparation: renamed standard symbols \<ll> to \<lless> and
   427 \<gg> to \<ggreater>;
   428 
   429 
   430 *** Document preparation ***
   431 
   432 * \isabellestyle{NAME} selects version of Isabelle output (currently
   433 available: are "it" for near math-mode best-style output, "sl" for
   434 slanted text style, and "tt" for plain type-writer; if no
   435 \isabellestyle command is given, output is according to slanted
   436 type-writer);
   437 
   438 * support sub/super scripts (for single symbols only), input syntax is
   439 like this: "A\<^sup>*" or "A\<^sup>\<star>";
   440 
   441 * some more standard symbols; see Appendix A of the system manual for
   442 the complete list of symbols defined in isabellesym.sty;
   443 
   444 * improved isabelle style files; more abstract symbol implementation
   445 (should now use \isamath{...} and \isatext{...} in custom symbol
   446 definitions);
   447 
   448 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
   449 state; Note that presentation of goal states does not conform to
   450 actual human-readable proof documents.  Please do not include goal
   451 states into document output unless you really know what you are doing!
   452 
   453 * proper indentation of antiquoted output with proportional LaTeX
   454 fonts;
   455 
   456 * no_document ML operator temporarily disables LaTeX document
   457 generation;
   458 
   459 * isatool unsymbolize tunes sources for plain ASCII communication;
   460 
   461 
   462 *** Isar ***
   463 
   464 * Pure: Isar now suffers initial goal statements to contain unbound
   465 schematic variables (this does not conform to actual readable proof
   466 documents, due to unpredictable outcome and non-compositional proof
   467 checking); users who know what they are doing may use schematic goals
   468 for Prolog-style synthesis of proven results;
   469 
   470 * Pure: assumption method (an implicit finishing) now handles actual
   471 rules as well;
   472 
   473 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
   474 initial goal, declare "that" only as Pure intro (only for single
   475 steps); the "that" rule assumption may now be involved in implicit
   476 finishing, thus ".." becomes a feasible for trivial obtains;
   477 
   478 * Pure: default proof step now includes 'intro_classes'; thus trivial
   479 instance proofs may be performed by "..";
   480 
   481 * Pure: ?thesis / ?this / "..." now work for pure meta-level
   482 statements as well;
   483 
   484 * Pure: more robust selection of calculational rules;
   485 
   486 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
   487 rule (as well as the assumption rule);
   488 
   489 * Pure: 'thm_deps' command visualizes dependencies of theorems and
   490 lemmas, using the graph browser tool;
   491 
   492 * Pure: predict failure of "show" in interactive mode;
   493 
   494 * Pure: 'thms_containing' now takes actual terms as arguments;
   495 
   496 * HOL: improved method 'induct' --- now handles non-atomic goals
   497 (potential INCOMPATIBILITY); tuned error handling;
   498 
   499 * HOL: cases and induct rules now provide explicit hints about the
   500 number of facts to be consumed (0 for "type" and 1 for "set" rules);
   501 any remaining facts are inserted into the goal verbatim;
   502 
   503 * HOL: local contexts (aka cases) may now contain term bindings as
   504 well; the 'cases' and 'induct' methods new provide a ?case binding for
   505 the result to be shown in each case;
   506 
   507 * HOL: added 'recdef_tc' command;
   508 
   509 * isatool convert assists in eliminating legacy ML scripts;
   510 
   511 
   512 *** HOL ***
   513 
   514 * HOL/Library: a collection of generic theories to be used together
   515 with main HOL; the theory loader path already includes this directory
   516 by default; the following existing theories have been moved here:
   517 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
   518 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
   519 
   520 * HOL/Unix: "Some aspects of Unix file-system security", a typical
   521 modelling and verification task performed in Isabelle/HOL +
   522 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
   523 
   524 * HOL/Algebra: special summation operator SUM no longer exists, it has
   525 been replaced by setsum; infix 'assoc' now has priority 50 (like
   526 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
   527 'domain', this makes the theory consistent with mathematical
   528 literature;
   529 
   530 * HOL basics: added overloaded operations "inverse" and "divide"
   531 (infix "/"), syntax for generic "abs" operation, generic summation
   532 operator \<Sum>;
   533 
   534 * HOL/typedef: simplified package, provide more useful rules (see also
   535 HOL/subset.thy);
   536 
   537 * HOL/datatype: induction rule for arbitrarily branching datatypes is
   538 now expressed as a proper nested rule (old-style tactic scripts may
   539 require atomize_strip_tac to cope with non-atomic premises);
   540 
   541 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
   542 to "split_conv" (old name still available for compatibility);
   543 
   544 * HOL: improved concrete syntax for strings (e.g. allows translation
   545 rules with string literals);
   546 
   547 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
   548  and Fleuriot's mechanization of analysis, including the transcendental
   549  functions for the reals;
   550 
   551 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
   552 
   553 
   554 *** CTT ***
   555 
   556 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
   557 "lam" is displayed as TWO lambda-symbols
   558 
   559 * CTT: theory Main now available, containing everything (that is, Bool
   560 and Arith);
   561 
   562 
   563 *** General ***
   564 
   565 * Pure: the Simplifier has been implemented properly as a derived rule
   566 outside of the actual kernel (at last!); the overall performance
   567 penalty in practical applications is about 50%, while reliability of
   568 the Isabelle inference kernel has been greatly improved;
   569 
   570 * print modes "brackets" and "no_brackets" control output of nested =>
   571 (types) and ==> (props); the default behaviour is "brackets";
   572 
   573 * Provers: fast_tac (and friends) now handle actual object-logic rules
   574 as assumptions as well;
   575 
   576 * system: support Poly/ML 4.0;
   577 
   578 * system: isatool install handles KDE version 1 or 2;
   579 
   580 
   581 
   582 New in Isabelle99-1 (October 2000)
   583 ----------------------------------
   584 
   585 *** Overview of INCOMPATIBILITIES ***
   586 
   587 * HOL: simplification of natural numbers is much changed; to partly
   588 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
   589 issue the following ML commands:
   590 
   591   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
   592   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
   593 
   594 * HOL: simplification no longer dives into case-expressions; this is
   595 controlled by "t.weak_case_cong" for each datatype t;
   596 
   597 * HOL: nat_less_induct renamed to less_induct;
   598 
   599 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
   600 fixsome to patch .thy and .ML sources automatically;
   601 
   602   select_equality  -> some_equality
   603   select_eq_Ex     -> some_eq_ex
   604   selectI2EX       -> someI2_ex
   605   selectI2         -> someI2
   606   selectI          -> someI
   607   select1_equality -> some1_equality
   608   Eps_sym_eq       -> some_sym_eq_trivial
   609   Eps_eq           -> some_eq_trivial
   610 
   611 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
   612 
   613 * HOL: removed obsolete theorem binding expand_if (refer to split_if
   614 instead);
   615 
   616 * HOL: the recursion equations generated by 'recdef' are now called
   617 f.simps instead of f.rules;
   618 
   619 * HOL: qed_spec_mp now also handles bounded ALL as well;
   620 
   621 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
   622 sometimes be needed;
   623 
   624 * HOL: the constant for "f``x" is now "image" rather than "op ``";
   625 
   626 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
   627 
   628 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
   629 product is now "<*>" instead of "Times"; the lexicographic product is
   630 now "<*lex*>" instead of "**";
   631 
   632 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
   633 of main HOL, but was unused); better use HOL's datatype package;
   634 
   635 * HOL: removed "symbols" syntax for constant "override" of theory Map;
   636 the old syntax may be recovered as follows:
   637 
   638   syntax (symbols)
   639     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
   640       (infixl "\\<oplus>" 100)
   641 
   642 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   643 
   644 * HOL/ML: even fewer consts are declared as global (see theories Ord,
   645 Lfp, Gfp, WF); this only affects ML packages that refer to const names
   646 internally;
   647 
   648 * HOL and ZF: syntax for quotienting wrt an equivalence relation
   649 changed from A/r to A//r;
   650 
   651 * ZF: new treatment of arithmetic (nat & int) may break some old
   652 proofs;
   653 
   654 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
   655 rulify -> rule_format, elimify -> elim_format, ...);
   656 
   657 * Isar/Provers: intro/elim/dest attributes changed; renamed
   658 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
   659 should have to change intro!! to intro? only); replaced "delrule" by
   660 "rule del";
   661 
   662 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
   663 
   664 * Provers: strengthened force_tac by using new first_best_tac;
   665 
   666 * LaTeX document preparation: several changes of isabelle.sty (see
   667 lib/texinputs);
   668 
   669 
   670 *** Document preparation ***
   671 
   672 * formal comments (text blocks etc.) in new-style theories may now
   673 contain antiquotations of thm/prop/term/typ/text to be presented
   674 according to latex print mode; concrete syntax is like this:
   675 @{term[show_types] "f(x) = a + x"};
   676 
   677 * isatool mkdir provides easy setup of Isabelle session directories,
   678 including proper document sources;
   679 
   680 * generated LaTeX sources are now deleted after successful run
   681 (isatool document -c); may retain a copy somewhere else via -D option
   682 of isatool usedir;
   683 
   684 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
   685 style files, achieving self-contained LaTeX sources and simplifying
   686 LaTeX debugging;
   687 
   688 * old-style theories now produce (crude) LaTeX output as well;
   689 
   690 * browser info session directories are now self-contained (may be put
   691 on WWW server seperately); improved graphs of nested sessions; removed
   692 graph for 'all sessions';
   693 
   694 * several improvements in isabelle style files; \isabellestyle{it}
   695 produces fake math mode output; \isamarkupheader is now \section by
   696 default; see lib/texinputs/isabelle.sty etc.;
   697 
   698 
   699 *** Isar ***
   700 
   701 * Isar/Pure: local results and corresponding term bindings are now
   702 subject to Hindley-Milner polymorphism (similar to ML); this
   703 accommodates incremental type-inference very nicely;
   704 
   705 * Isar/Pure: new derived language element 'obtain' supports
   706 generalized existence reasoning;
   707 
   708 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
   709 support accumulation of results, without applying any rules yet;
   710 useful to collect intermediate results without explicit name
   711 references, and for use with transitivity rules with more than 2
   712 premises;
   713 
   714 * Isar/Pure: scalable support for case-analysis type proofs: new
   715 'case' language element refers to local contexts symbolically, as
   716 produced by certain proof methods; internally, case names are attached
   717 to theorems as "tags";
   718 
   719 * Isar/Pure: theory command 'hide' removes declarations from
   720 class/type/const name spaces;
   721 
   722 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
   723 indicate potential overloading;
   724 
   725 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
   726 
   727 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
   728 "{a,b,c}" instead of {a,b,c};
   729 
   730 * Isar/Pure now provides its own version of intro/elim/dest
   731 attributes; useful for building new logics, but beware of confusion
   732 with the version in Provers/classical;
   733 
   734 * Isar/Pure: the local context of (non-atomic) goals is provided via
   735 case name 'antecedent';
   736 
   737 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
   738 to the current context is now done automatically);
   739 
   740 * Isar/Pure: theory command 'method_setup' provides a simple interface
   741 for definining proof methods in ML;
   742 
   743 * Isar/Provers: intro/elim/dest attributes changed; renamed
   744 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
   745 most cases, one should have to change intro!! to intro? only);
   746 replaced "delrule" by "rule del";
   747 
   748 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
   749 'symmetric' attribute (the latter supercedes [RS sym]);
   750 
   751 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
   752 method modifier); 'simp' method: 'only:' modifier removes loopers as
   753 well (including splits);
   754 
   755 * Isar/Provers: Simplifier and Classical methods now support all kind
   756 of modifiers used in the past, including 'cong', 'iff', etc.
   757 
   758 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
   759 of Simplifier and Classical reasoner);
   760 
   761 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
   762 now support named cases; major packages (inductive, datatype, primrec,
   763 recdef) support case names and properly name parameters;
   764 
   765 * Isar/HOL: new transitivity rules for substitution in inequalities --
   766 monotonicity conditions are extracted to be proven at end of
   767 calculations;
   768 
   769 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
   770 method anyway;
   771 
   772 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
   773 split_if split_if_asm; datatype package provides theorems foo.splits =
   774 foo.split foo.split_asm for each datatype;
   775 
   776 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
   777 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
   778 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
   779 use "(cases (simplified))" method in proper proof texts);
   780 
   781 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
   782 
   783 * Isar: names of theorems etc. may be natural numbers as well;
   784 
   785 * Isar: 'pr' command: optional arguments for goals_limit and
   786 ProofContext.prems_limit; no longer prints theory contexts, but only
   787 proof states;
   788 
   789 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
   790 additional print modes to be specified; e.g. "pr(latex)" will print
   791 proof state according to the Isabelle LaTeX style;
   792 
   793 * Isar: improved support for emulating tactic scripts, including proof
   794 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
   795 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
   796 (for HOL datatypes);
   797 
   798 * Isar: simplified (more robust) goal selection of proof methods: 1st
   799 goal, all goals, or explicit goal specifier (tactic emulation); thus
   800 'proof method scripts' have to be in depth-first order;
   801 
   802 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
   803 
   804 * Isar: removed 'help' command, which hasn't been too helpful anyway;
   805 should instead use individual commands for printing items
   806 (print_commands, print_methods etc.);
   807 
   808 * Isar: added 'nothing' --- the empty list of theorems;
   809 
   810 
   811 *** HOL ***
   812 
   813 * HOL/MicroJava: formalization of a fragment of Java, together with a
   814 corresponding virtual machine and a specification of its bytecode
   815 verifier and a lightweight bytecode verifier, including proofs of
   816 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
   817 Cornelia Pusch (see also the homepage of project Bali at
   818 http://isabelle.in.tum.de/Bali/);
   819 
   820 * HOL/Algebra: new theory of rings and univariate polynomials, by
   821 Clemens Ballarin;
   822 
   823 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
   824 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
   825 Rasmussen;
   826 
   827 * HOL/Lattice: fundamental concepts of lattice theory and order
   828 structures, including duals, properties of bounds versus algebraic
   829 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
   830 Theorem for complete lattices etc.; may also serve as a demonstration
   831 for abstract algebraic reasoning using axiomatic type classes, and
   832 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
   833 
   834 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
   835 von Oheimb;
   836 
   837 * HOL/IMPP: extension of IMP with local variables and mutually
   838 recursive procedures, by David von Oheimb;
   839 
   840 * HOL/Lambda: converted into new-style theory and document;
   841 
   842 * HOL/ex/Multiquote: example of multiple nested quotations and
   843 anti-quotations -- basically a generalized version of de-Bruijn
   844 representation; very useful in avoiding lifting of operations;
   845 
   846 * HOL/record: added general record equality rule to simpset; fixed
   847 select-update simplification procedure to handle extended records as
   848 well; admit "r" as field name;
   849 
   850 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
   851 other numeric types and also as the identity of groups, rings, etc.;
   852 
   853 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
   854 Types nat and int belong to this axclass;
   855 
   856 * HOL: greatly improved simplification involving numerals of type nat, int, real:
   857    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
   858    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
   859   two terms #m*u and #n*u are replaced by #(m+n)*u
   860     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
   861   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
   862     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
   863 
   864 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
   865 powerful prover for predicate logic but knows nothing of clasets; see
   866 ex/mesontest.ML and ex/mesontest2.ML for example applications;
   867 
   868 * HOL: new version of "case_tac" subsumes both boolean case split and
   869 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
   870 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
   871 
   872 * HOL: simplification no longer dives into case-expressions: only the
   873 selector expression is simplified, but not the remaining arms; to
   874 enable full simplification of case-expressions for datatype t, you may
   875 remove t.weak_case_cong from the simpset, either globally (Delcongs
   876 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
   877 
   878 * HOL/recdef: the recursion equations generated by 'recdef' for
   879 function 'f' are now called f.simps instead of f.rules; if all
   880 termination conditions are proved automatically, these simplification
   881 rules are added to the simpset, as in primrec; rules may be named
   882 individually as well, resulting in a separate list of theorems for
   883 each equation;
   884 
   885 * HOL/While is a new theory that provides a while-combinator. It
   886 permits the definition of tail-recursive functions without the
   887 provision of a termination measure. The latter is necessary once the
   888 invariant proof rule for while is applied.
   889 
   890 * HOL: new (overloaded) notation for the set of elements below/above
   891 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
   892 
   893 * HOL: theorems impI, allI, ballI bound as "strip";
   894 
   895 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
   896 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
   897 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
   898 
   899 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   900 
   901 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
   902 main HOL, but was unused);
   903 
   904 * HOL: fewer consts declared as global (e.g. have to refer to
   905 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
   906 
   907 * HOL: tuned AST representation of nested pairs, avoiding bogus output
   908 in case of overlap with user translations (e.g. judgements over
   909 tuples); (note that the underlying logical represenation is still
   910 bogus);
   911 
   912 
   913 *** ZF ***
   914 
   915 * ZF: simplification automatically cancels common terms in arithmetic
   916 expressions over nat and int;
   917 
   918 * ZF: new treatment of nat to minimize type-checking: all operators
   919 coerce their operands to a natural number using the function natify,
   920 making the algebraic laws unconditional;
   921 
   922 * ZF: as above, for int: operators coerce their operands to an integer
   923 using the function intify;
   924 
   925 * ZF: the integer library now contains many of the usual laws for the
   926 orderings, including $<=, and monotonicity laws for $+ and $*;
   927 
   928 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
   929 simplification;
   930 
   931 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
   932 to the simplifier and classical reasoner simultaneously;
   933 
   934 
   935 *** General ***
   936 
   937 * Provers: blast_tac now handles actual object-logic rules as
   938 assumptions; note that auto_tac uses blast_tac internally as well;
   939 
   940 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
   941 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
   942 
   943 * Provers: delrules now handles destruct rules as well (no longer need
   944 explicit make_elim);
   945 
   946 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
   947   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   948 use instead the strong form,
   949   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   950 in HOL, FOL and ZF the function cla_make_elim will create such rules
   951 from destruct-rules;
   952 
   953 * Provers: Simplifier.easy_setup provides a fast path to basic
   954 Simplifier setup for new object-logics;
   955 
   956 * Pure: AST translation rules no longer require constant head on LHS;
   957 
   958 * Pure: improved name spaces: ambiguous output is qualified; support
   959 for hiding of names;
   960 
   961 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
   962 XSYMBOL_HOME; no longer need to do manual configuration in most
   963 situations;
   964 
   965 * system: compression of ML heaps images may now be controlled via -c
   966 option of isabelle and isatool usedir (currently only observed by
   967 Poly/ML);
   968 
   969 * system: isatool installfonts may handle X-Symbol fonts as well (very
   970 useful for remote X11);
   971 
   972 * system: provide TAGS file for Isabelle sources;
   973 
   974 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
   975 order;
   976 
   977 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
   978 timing flag supersedes proof_timing and Toplevel.trace;
   979 
   980 * ML: new combinators |>> and |>>> for incremental transformations
   981 with secondary results (e.g. certain theory extensions):
   982 
   983 * ML: PureThy.add_defs gets additional argument to indicate potential
   984 overloading (usually false);
   985 
   986 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
   987 results;
   988 
   989 
   990 
   991 New in Isabelle99 (October 1999)
   992 --------------------------------
   993 
   994 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   995 
   996 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
   997 are no longer simplified.  (This allows the simplifier to unfold recursive
   998 functional programs.)  To restore the old behaviour, declare
   999 
  1000     Delcongs [if_weak_cong];
  1001 
  1002 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  1003 complement;
  1004 
  1005 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  1006 
  1007 * HOL/datatype: mutual_induct_tac no longer exists --
  1008   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  1009 
  1010 * HOL/typedef: fixed type inference for representing set; type
  1011 arguments now have to occur explicitly on the rhs as type constraints;
  1012 
  1013 * ZF: The con_defs part of an inductive definition may no longer refer
  1014 to constants declared in the same theory;
  1015 
  1016 * HOL, ZF: the function mk_cases, generated by the inductive
  1017 definition package, has lost an argument.  To simplify its result, it
  1018 uses the default simpset instead of a supplied list of theorems.
  1019 
  1020 * HOL/List: the constructors of type list are now Nil and Cons;
  1021 
  1022 * Simplifier: the type of the infix ML functions
  1023         setSSolver addSSolver setSolver addSolver
  1024 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  1025 for packaging solvers. A solver is created via
  1026         mk_solver: string -> (thm list -> int -> tactic) -> solver
  1027 where the string argument is only a comment.
  1028 
  1029 
  1030 *** Proof tools ***
  1031 
  1032 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  1033 decision procedure for linear arithmetic. Currently it is used for
  1034 types `nat', `int', and `real' in HOL (see below); it can, should and
  1035 will be instantiated for other types and logics as well.
  1036 
  1037 * The simplifier now accepts rewrite rules with flexible heads, eg
  1038      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  1039   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  1040   matching.
  1041 
  1042 
  1043 *** General ***
  1044 
  1045 * New Isabelle/Isar subsystem provides an alternative to traditional
  1046 tactical theorem proving; together with the ProofGeneral/isar user
  1047 interface it offers an interactive environment for developing human
  1048 readable proof documents (Isar == Intelligible semi-automated
  1049 reasoning); for further information see isatool doc isar-ref,
  1050 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  1051 
  1052 * improved and simplified presentation of theories: better HTML markup
  1053 (including colors), graph views in several sizes; isatool usedir now
  1054 provides a proper interface for user theories (via -P option); actual
  1055 document preparation based on (PDF)LaTeX is available as well (for
  1056 new-style theories only); see isatool doc system for more information;
  1057 
  1058 * native support for Proof General, both for classic Isabelle and
  1059 Isabelle/Isar;
  1060 
  1061 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  1062 using the graph browser tool;
  1063 
  1064 * Isabelle manuals now also available as PDF;
  1065 
  1066 * theory loader rewritten from scratch (may not be fully
  1067 bug-compatible); old loadpath variable has been replaced by show_path,
  1068 add_path, del_path, reset_path functions; new operations such as
  1069 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  1070 isatool doc ref);
  1071 
  1072 * improved isatool install: option -k creates KDE application icon,
  1073 option -p DIR installs standalone binaries;
  1074 
  1075 * added ML_PLATFORM setting (useful for cross-platform installations);
  1076 more robust handling of platform specific ML images for SML/NJ;
  1077 
  1078 * the settings environment is now statically scoped, i.e. it is never
  1079 created again in sub-processes invoked from isabelle, isatool, or
  1080 Isabelle;
  1081 
  1082 * path element specification '~~' refers to '$ISABELLE_HOME';
  1083 
  1084 * in locales, the "assumes" and "defines" parts may be omitted if
  1085 empty;
  1086 
  1087 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  1088 long arrows);
  1089 
  1090 * new print_mode "HTML";
  1091 
  1092 * new flag show_tags controls display of tags of theorems (which are
  1093 basically just comments that may be attached by some tools);
  1094 
  1095 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  1096 mode and goal output format:
  1097 
  1098 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  1099 244c244
  1100 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  1101 ---
  1102 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  1103 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  1104 181c181
  1105 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  1106 ---
  1107 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  1108 
  1109 * function bind_thms stores lists of theorems (cf. bind_thm);
  1110 
  1111 * new shorthand tactics ftac, eatac, datac, fatac;
  1112 
  1113 * qed (and friends) now accept "" as result name; in that case the
  1114 theorem is not stored, but proper checks and presentation of the
  1115 result still apply;
  1116 
  1117 * theorem database now also indexes constants "Trueprop", "all",
  1118 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  1119 
  1120 
  1121 *** HOL ***
  1122 
  1123 ** HOL arithmetic **
  1124 
  1125 * There are now decision procedures for linear arithmetic over nat and
  1126 int:
  1127 
  1128 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  1129 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  1130 are treated as atomic; subformulae not involving type `nat' or `int'
  1131 are ignored; quantified subformulae are ignored unless they are
  1132 positive universal or negative existential. The tactic has to be
  1133 invoked by hand and can be a little bit slow. In particular, the
  1134 running time is exponential in the number of occurrences of `min' and
  1135 `max', and `-' on `nat'.
  1136 
  1137 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  1138 (negated) (in)equalities among the premises and the conclusion into
  1139 account (i.e. no compound formulae) and does not know about `min' and
  1140 `max', and `-' on `nat'. It is fast and is used automatically by the
  1141 simplifier.
  1142 
  1143 NB: At the moment, these decision procedures do not cope with mixed
  1144 nat/int formulae where the two parts interact, such as `m < n ==>
  1145 int(m) < int(n)'.
  1146 
  1147 * HOL/Numeral provides a generic theory of numerals (encoded
  1148 efficiently as bit strings); setup for types nat/int/real is in place;
  1149 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  1150 int, existing theories and proof scripts may require a few additional
  1151 type constraints;
  1152 
  1153 * integer division and remainder can now be performed on constant
  1154 arguments;
  1155 
  1156 * many properties of integer multiplication, division and remainder
  1157 are now available;
  1158 
  1159 * An interface to the Stanford Validity Checker (SVC) is available through the
  1160 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  1161 are proved automatically.  SVC must be installed separately, and its results
  1162 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  1163 invocation of the underlying oracle).  For SVC see
  1164   http://verify.stanford.edu/SVC
  1165 
  1166 * IsaMakefile: the HOL-Real target now builds an actual image;
  1167 
  1168 
  1169 ** HOL misc **
  1170 
  1171 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  1172 (in Isabelle/Isar) -- by Gertrud Bauer;
  1173 
  1174 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  1175 analysis for assembly languages with subtypes;
  1176 
  1177 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  1178 -- avoids syntactic ambiguities and treats state, transition, and
  1179 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  1180 changed syntax and (many) tactics;
  1181 
  1182 * HOL/inductive: Now also handles more general introduction rules such
  1183   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  1184   theorems are now maintained within the theory (maintained via the
  1185   "mono" attribute);
  1186 
  1187 * HOL/datatype: Now also handles arbitrarily branching datatypes
  1188   (using function types) such as
  1189 
  1190   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  1191 
  1192 * HOL/record: record_simproc (part of the default simpset) takes care
  1193 of selectors applied to updated records; record_split_tac is no longer
  1194 part of the default claset; update_defs may now be removed from the
  1195 simpset in many cases; COMPATIBILITY: old behavior achieved by
  1196 
  1197   claset_ref () := claset() addSWrapper record_split_wrapper;
  1198   Delsimprocs [record_simproc]
  1199 
  1200 * HOL/typedef: fixed type inference for representing set; type
  1201 arguments now have to occur explicitly on the rhs as type constraints;
  1202 
  1203 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  1204 names rather than an ML expression;
  1205 
  1206 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  1207 supplied later.  Program schemes can be defined, such as
  1208     "While B C s = (if B s then While B C (C s) else s)"
  1209 where the well-founded relation can be chosen after B and C have been given.
  1210 
  1211 * HOL/List: the constructors of type list are now Nil and Cons;
  1212 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  1213 course, ML tools referring to List.list.op # etc. have to be adapted;
  1214 
  1215 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  1216 disabled by default; run isabelle with option -m HOL to get back to
  1217 the original Gordon/HOL-style output;
  1218 
  1219 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  1220 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  1221 
  1222 * HOL basic syntax simplified (more orthogonal): all variants of
  1223 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  1224 Eps operator is provided as well: "SOME x. P[x]";
  1225 
  1226 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  1227 
  1228 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  1229 thus available for user theories;
  1230 
  1231 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  1232 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  1233 time;
  1234 
  1235 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  1236 several times and then mp;
  1237 
  1238 
  1239 *** LK ***
  1240 
  1241 * the notation <<...>> is now available as a notation for sequences of
  1242 formulas;
  1243 
  1244 * the simplifier is now installed
  1245 
  1246 * the axiom system has been generalized (thanks to Soren Heilmann)
  1247 
  1248 * the classical reasoner now has a default rule database
  1249 
  1250 
  1251 *** ZF ***
  1252 
  1253 * new primrec section allows primitive recursive functions to be given
  1254 directly (as in HOL) over datatypes and the natural numbers;
  1255 
  1256 * new tactics induct_tac and exhaust_tac for induction (or case
  1257 analysis) over datatypes and the natural numbers;
  1258 
  1259 * the datatype declaration of type T now defines the recursor T_rec;
  1260 
  1261 * simplification automatically does freeness reasoning for datatype
  1262 constructors;
  1263 
  1264 * automatic type-inference, with AddTCs command to insert new
  1265 type-checking rules;
  1266 
  1267 * datatype introduction rules are now added as Safe Introduction rules
  1268 to the claset;
  1269 
  1270 * the syntax "if P then x else y" is now available in addition to
  1271 if(P,x,y);
  1272 
  1273 
  1274 *** Internal programming interfaces ***
  1275 
  1276 * tuned simplifier trace output; new flag debug_simp;
  1277 
  1278 * structures Vartab / Termtab (instances of TableFun) offer efficient
  1279 tables indexed by indexname_ord / term_ord (compatible with aconv);
  1280 
  1281 * AxClass.axclass_tac lost the theory argument;
  1282 
  1283 * tuned current_goals_markers semantics: begin / end goal avoids
  1284 printing empty lines;
  1285 
  1286 * removed prs and prs_fn hook, which was broken because it did not
  1287 include \n in its semantics, forcing writeln to add one
  1288 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  1289 string -> unit if you really want to output text without newline;
  1290 
  1291 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  1292 plain output, interface builders may have to enable 'isabelle_font'
  1293 mode to get Isabelle font glyphs as before;
  1294 
  1295 * refined token_translation interface; INCOMPATIBILITY: output length
  1296 now of type real instead of int;
  1297 
  1298 * theory loader actions may be traced via new ThyInfo.add_hook
  1299 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  1300 your own database of information attached to *whole* theories -- as
  1301 opposed to intra-theory data slots offered via TheoryDataFun;
  1302 
  1303 * proper handling of dangling sort hypotheses (at last!);
  1304 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  1305 extra sort hypotheses that can be witnessed from the type signature;
  1306 the force_strip_shyps flag is gone, any remaining shyps are simply
  1307 left in the theorem (with a warning issued by strip_shyps_warning);
  1308 
  1309 
  1310 
  1311 New in Isabelle98-1 (October 1998)
  1312 ----------------------------------
  1313 
  1314 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1315 
  1316 * several changes of automated proof tools;
  1317 
  1318 * HOL: major changes to the inductive and datatype packages, including
  1319 some minor incompatibilities of theory syntax;
  1320 
  1321 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  1322 called `inj_on';
  1323 
  1324 * HOL: removed duplicate thms in Arith:
  1325   less_imp_add_less  should be replaced by  trans_less_add1
  1326   le_imp_add_le      should be replaced by  trans_le_add1
  1327 
  1328 * HOL: unary minus is now overloaded (new type constraints may be
  1329 required);
  1330 
  1331 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  1332 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  1333 now taken as an integer constant.
  1334 
  1335 * Pure: ML function 'theory_of' renamed to 'theory';
  1336 
  1337 
  1338 *** Proof tools ***
  1339 
  1340 * Simplifier:
  1341   1. Asm_full_simp_tac is now more aggressive.
  1342      1. It will sometimes reorient premises if that increases their power to
  1343         simplify.
  1344      2. It does no longer proceed strictly from left to right but may also
  1345         rotate premises to achieve further simplification.
  1346      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  1347      old Asm_full_simp_tac in that it does not rotate premises.
  1348   2. The simplifier now knows a little bit about nat-arithmetic.
  1349 
  1350 * Classical reasoner: wrapper mechanism for the classical reasoner now
  1351 allows for selected deletion of wrappers, by introduction of names for
  1352 wrapper functionals.  This implies that addbefore, addSbefore,
  1353 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  1354 and that adding two tactics with the same name overwrites the first
  1355 one (emitting a warning).
  1356   type wrapper = (int -> tactic) -> (int -> tactic)
  1357   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  1358   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  1359   delWrapper, delSWrapper: claset *  string            -> claset
  1360   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  1361 
  1362 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  1363 semantics; addbefore now affects only the unsafe part of step_tac
  1364 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  1365 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  1366 by Force_tac;
  1367 
  1368 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  1369 compWrapper; added safe wrapper (and access functions for it);
  1370 
  1371 * HOL/split_all_tac is now much faster and fails if there is nothing
  1372 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  1373 and the names of the automatically generated variables have changed.
  1374 split_all_tac has moved within claset() from unsafe wrappers to safe
  1375 wrappers, which means that !!-bound variables are split much more
  1376 aggressively, and safe_tac and clarify_tac now split such variables.
  1377 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  1378 Note: the same holds for record_split_tac, which does the job of
  1379 split_all_tac for record fields.
  1380 
  1381 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  1382 permanently to the default simpset using Addsplits just like
  1383 Addsimps. They can be removed via Delsplits just like
  1384 Delsimps. Lower-case versions are also available.
  1385 
  1386 * HOL/Simplifier: The rule split_if is now part of the default
  1387 simpset. This means that the simplifier will eliminate all occurrences
  1388 of if-then-else in the conclusion of a goal. To prevent this, you can
  1389 either remove split_if completely from the default simpset by
  1390 `Delsplits [split_if]' or remove it in a specific call of the
  1391 simplifier using `... delsplits [split_if]'.  You can also add/delete
  1392 other case splitting rules to/from the default simpset: every datatype
  1393 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  1394 t is the name of the datatype).
  1395 
  1396 * Classical reasoner / Simplifier combination: new force_tac (and
  1397 derivatives Force_tac, force) combines rewriting and classical
  1398 reasoning (and whatever other tools) similarly to auto_tac, but is
  1399 aimed to solve the given subgoal completely.
  1400 
  1401 
  1402 *** General ***
  1403 
  1404 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  1405 and `goalw': the theory is no longer needed as an explicit argument -
  1406 the current theory context is used; assumptions are no longer returned
  1407 at the ML-level unless one of them starts with ==> or !!; it is
  1408 recommended to convert to these new commands using isatool fixgoal
  1409 (backup your sources first!);
  1410 
  1411 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  1412 the current theory context, and 'theory' to lookup stored theories;
  1413 
  1414 * new theory section 'locale' for declaring constants, assumptions and
  1415 definitions that have local scope;
  1416 
  1417 * new theory section 'nonterminals' for purely syntactic types;
  1418 
  1419 * new theory section 'setup' for generic ML setup functions
  1420 (e.g. package initialization);
  1421 
  1422 * the distribution now includes Isabelle icons: see
  1423 lib/logo/isabelle-{small,tiny}.xpm;
  1424 
  1425 * isatool install - install binaries with absolute references to
  1426 ISABELLE_HOME/bin;
  1427 
  1428 * isatool logo -- create instances of the Isabelle logo (as EPS);
  1429 
  1430 * print mode 'emacs' reserved for Isamode;
  1431 
  1432 * support multiple print (ast) translations per constant name;
  1433 
  1434 * theorems involving oracles are now printed with a suffixed [!];
  1435 
  1436 
  1437 *** HOL ***
  1438 
  1439 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  1440 
  1441 * HOL/inductive package reorganized and improved: now supports mutual
  1442 definitions such as
  1443 
  1444   inductive EVEN ODD
  1445     intrs
  1446       null "0 : EVEN"
  1447       oddI "n : EVEN ==> Suc n : ODD"
  1448       evenI "n : ODD ==> Suc n : EVEN"
  1449 
  1450 new theorem list "elims" contains an elimination rule for each of the
  1451 recursive sets; inductive definitions now handle disjunctive premises
  1452 correctly (also ZF);
  1453 
  1454 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  1455 "mutual_induct" no longer exists - the induction rule is always
  1456 contained in "induct";
  1457 
  1458 
  1459 * HOL/datatype package re-implemented and greatly improved: now
  1460 supports mutually recursive datatypes such as
  1461 
  1462   datatype
  1463     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  1464             | SUM ('a aexp) ('a aexp)
  1465             | DIFF ('a aexp) ('a aexp)
  1466             | NUM 'a
  1467   and
  1468     'a bexp = LESS ('a aexp) ('a aexp)
  1469             | AND ('a bexp) ('a bexp)
  1470             | OR ('a bexp) ('a bexp)
  1471 
  1472 as well as indirectly recursive datatypes such as
  1473 
  1474   datatype
  1475     ('a, 'b) term = Var 'a
  1476                   | App 'b ((('a, 'b) term) list)
  1477 
  1478 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  1479 induction on mutually / indirectly recursive datatypes.
  1480 
  1481 Primrec equations are now stored in theory and can be accessed via
  1482 <function_name>.simps.
  1483 
  1484 INCOMPATIBILITIES:
  1485 
  1486   - Theories using datatypes must now have theory Datatype as an
  1487     ancestor.
  1488   - The specific <typename>.induct_tac no longer exists - use the
  1489     generic induct_tac instead.
  1490   - natE has been renamed to nat.exhaust - use exhaust_tac
  1491     instead of res_inst_tac ... natE. Note that the variable
  1492     names in nat.exhaust differ from the names in natE, this
  1493     may cause some "fragile" proofs to fail.
  1494   - The theorems split_<typename>_case and split_<typename>_case_asm
  1495     have been renamed to <typename>.split and <typename>.split_asm.
  1496   - Since default sorts of type variables are now handled correctly,
  1497     some datatype definitions may have to be annotated with explicit
  1498     sort constraints.
  1499   - Primrec definitions no longer require function name and type
  1500     of recursive argument.
  1501 
  1502 Consider using isatool fixdatatype to adapt your theories and proof
  1503 scripts to the new package (backup your sources first!).
  1504 
  1505 
  1506 * HOL/record package: considerably improved implementation; now
  1507 includes concrete syntax for record types, terms, updates; theorems
  1508 for surjective pairing and splitting !!-bound record variables; proof
  1509 support is as follows:
  1510 
  1511   1) standard conversions (selectors or updates applied to record
  1512 constructor terms) are part of the standard simpset;
  1513 
  1514   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  1515 made part of standard simpset and claset via addIffs;
  1516 
  1517   3) a tactic for record field splitting (record_split_tac) is part of
  1518 the standard claset (addSWrapper);
  1519 
  1520 To get a better idea about these rules you may retrieve them via
  1521 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  1522 the name of your record type.
  1523 
  1524 The split tactic 3) conceptually simplifies by the following rule:
  1525 
  1526   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  1527 
  1528 Thus any record variable that is bound by meta-all will automatically
  1529 blow up into some record constructor term, consequently the
  1530 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  1531 solve record problems automatically.
  1532 
  1533 
  1534 * reorganized the main HOL image: HOL/Integ and String loaded by
  1535 default; theory Main includes everything;
  1536 
  1537 * automatic simplification of integer sums and comparisons, using cancellation;
  1538 
  1539 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  1540 
  1541 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  1542 
  1543 * many new identities for unions, intersections, set difference, etc.;
  1544 
  1545 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  1546 called split_if, split_split, split_sum_case and split_nat_case (to go
  1547 with add/delsplits);
  1548 
  1549 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  1550 (?x::unit) = (); this is made part of the default simpset, which COULD
  1551 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  1552 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  1553 unit_abs_eta_conv is added in order to counter the effect of
  1554 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  1555 %u.f();
  1556 
  1557 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  1558 makes more sense);
  1559 
  1560 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1561   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1562   disjointness reasoning but breaking a few old proofs.
  1563 
  1564 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  1565 to 'converse' from 'inverse' (for compatibility with ZF and some
  1566 literature);
  1567 
  1568 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  1569 the well-founded relation;
  1570 
  1571 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  1572     Compl A.  The "Compl" syntax remains available as input syntax for this
  1573     release ONLY.
  1574 
  1575 * HOL/Update: new theory of function updates:
  1576     f(a:=b) == %x. if x=a then b else f x
  1577 may also be iterated as in f(a:=b,c:=d,...);
  1578 
  1579 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  1580 
  1581 * HOL/List:
  1582   - new function list_update written xs[i:=v] that updates the i-th
  1583     list position. May also be iterated as in xs[i:=a,j:=b,...].
  1584   - new function `upt' written [i..j(] which generates the list
  1585     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  1586     bound write [i..j], which is a shorthand for [i..j+1(].
  1587   - new lexicographic orderings and corresponding wellfoundedness theorems.
  1588 
  1589 * HOL/Arith:
  1590   - removed 'pred' (predecessor) function;
  1591   - generalized some theorems about n-1;
  1592   - many new laws about "div" and "mod";
  1593   - new laws about greatest common divisors (see theory ex/Primes);
  1594 
  1595 * HOL/Relation: renamed the relational operator r^-1 "converse"
  1596 instead of "inverse";
  1597 
  1598 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  1599   of the multiset ordering;
  1600 
  1601 * directory HOL/Real: a construction of the reals using Dedekind cuts
  1602   (not included by default);
  1603 
  1604 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  1605 
  1606 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  1607   programs, i.e. different program variables may have different types.
  1608 
  1609 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1610   [previously, this check worked only if the rewrite rule was unconditional]
  1611   Now rew can involve either definitions or equalities (either == or =).
  1612 
  1613 
  1614 *** ZF ***
  1615 
  1616 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  1617   only the theorems proved on ZF.ML;
  1618 
  1619 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1620   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1621   disjointness reasoning but breaking a few old proofs.
  1622 
  1623 * ZF/Update: new theory of function updates
  1624     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  1625   may also be iterated as in f(a:=b,c:=d,...);
  1626 
  1627 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  1628 
  1629 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1630   [previously, this check worked only if the rewrite rule was unconditional]
  1631   Now rew can involve either definitions or equalities (either == or =).
  1632 
  1633 * case_tac provided for compatibility with HOL
  1634     (like the old excluded_middle_tac, but with subgoals swapped)
  1635 
  1636 
  1637 *** Internal programming interfaces ***
  1638 
  1639 * Pure: several new basic modules made available for general use, see
  1640 also src/Pure/README;
  1641 
  1642 * improved the theory data mechanism to support encapsulation (data
  1643 kind name replaced by private Object.kind, acting as authorization
  1644 key); new type-safe user interface via functor TheoryDataFun; generic
  1645 print_data function becomes basically useless;
  1646 
  1647 * removed global_names compatibility flag -- all theory declarations
  1648 are qualified by default;
  1649 
  1650 * module Pure/Syntax now offers quote / antiquote translation
  1651 functions (useful for Hoare logic etc. with implicit dependencies);
  1652 see HOL/ex/Antiquote for an example use;
  1653 
  1654 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  1655 cterm -> thm;
  1656 
  1657 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  1658 subgoal;
  1659 
  1660 * Display.print_goals function moved to Locale.print_goals;
  1661 
  1662 * standard print function for goals supports current_goals_markers
  1663 variable for marking begin of proof, end of proof, start of goal; the
  1664 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  1665 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  1666 for example;
  1667 
  1668 
  1669 
  1670 New in Isabelle98 (January 1998)
  1671 --------------------------------
  1672 
  1673 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1674 
  1675 * changed lexical syntax of terms / types: dots made part of long
  1676 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  1677 
  1678 * simpset (and claset) reference variable replaced by functions
  1679 simpset / simpset_ref;
  1680 
  1681 * no longer supports theory aliases (via merge) and non-trivial
  1682 implicit merge of thms' signatures;
  1683 
  1684 * most internal names of constants changed due to qualified names;
  1685 
  1686 * changed Pure/Sequence interface (see Pure/seq.ML);
  1687 
  1688 
  1689 *** General Changes ***
  1690 
  1691 * hierachically structured name spaces (for consts, types, axms, thms
  1692 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  1693 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  1694 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  1695 long_names for fully qualified output names; NOTE: ML programs
  1696 (special tactics, packages etc.) referring to internal names may have
  1697 to be adapted to cope with fully qualified names; in case of severe
  1698 backward campatibility problems try setting 'global_names' at compile
  1699 time to have enrything declared within a flat name space; one may also
  1700 fine tune name declarations in theories via the 'global' and 'local'
  1701 section;
  1702 
  1703 * reimplemented the implicit simpset and claset using the new anytype
  1704 data filed in signatures; references simpset:simpset ref etc. are
  1705 replaced by functions simpset:unit->simpset and
  1706 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  1707 to patch your ML files accordingly;
  1708 
  1709 * HTML output now includes theory graph data for display with Java
  1710 applet or isatool browser; data generated automatically via isatool
  1711 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  1712 
  1713 * defs may now be conditional; improved rewrite_goals_tac to handle
  1714 conditional equations;
  1715 
  1716 * defs now admits additional type arguments, using TYPE('a) syntax;
  1717 
  1718 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  1719 creates a new theory node; implicit merge of thms' signatures is
  1720 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  1721 transfer:theory->thm->thm in (rare) cases;
  1722 
  1723 * improved handling of draft signatures / theories; draft thms (and
  1724 ctyps, cterms) are automatically promoted to real ones;
  1725 
  1726 * slightly changed interfaces for oracles: admit many per theory, named
  1727 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  1728 
  1729 * print_goals: optional output of const types (set show_consts and
  1730 show_types);
  1731 
  1732 * improved output of warnings (###) and errors (***);
  1733 
  1734 * subgoal_tac displays a warning if the new subgoal has type variables;
  1735 
  1736 * removed old README and Makefiles;
  1737 
  1738 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  1739 
  1740 * removed obsolete init_pps and init_database;
  1741 
  1742 * deleted the obsolete tactical STATE, which was declared by
  1743     fun STATE tacfun st = tacfun st st;
  1744 
  1745 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  1746 (which abbreviates $HOME);
  1747 
  1748 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  1749 use isatool fixseq to adapt your ML programs (this works for fully
  1750 qualified references to the Sequence structure only!);
  1751 
  1752 * use_thy no longer requires writable current directory; it always
  1753 reloads .ML *and* .thy file, if either one is out of date;
  1754 
  1755 
  1756 *** Classical Reasoner ***
  1757 
  1758 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  1759 tactics that use classical reasoning to simplify a subgoal without
  1760 splitting it into several subgoals;
  1761 
  1762 * Safe_tac: like safe_tac but uses the default claset;
  1763 
  1764 
  1765 *** Simplifier ***
  1766 
  1767 * added simplification meta rules:
  1768     (asm_)(full_)simplify: simpset -> thm -> thm;
  1769 
  1770 * simplifier.ML no longer part of Pure -- has to be loaded by object
  1771 logics (again);
  1772 
  1773 * added prems argument to simplification procedures;
  1774 
  1775 * HOL, FOL, ZF: added infix function `addsplits':
  1776   instead of `<simpset> setloop (split_tac <thms>)'
  1777   you can simply write `<simpset> addsplits <thms>'
  1778 
  1779 
  1780 *** Syntax ***
  1781 
  1782 * TYPE('a) syntax for type reflection terms;
  1783 
  1784 * no longer handles consts with name "" -- declare as 'syntax' instead;
  1785 
  1786 * pretty printer: changed order of mixfix annotation preference (again!);
  1787 
  1788 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  1789 
  1790 
  1791 *** HOL ***
  1792 
  1793 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1794   with `addloop' of the simplifier to faciliate case splitting in premises.
  1795 
  1796 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  1797 
  1798 * HOL/Auth: new protocol proofs including some for the Internet
  1799   protocol TLS;
  1800 
  1801 * HOL/Map: new theory of `maps' a la VDM;
  1802 
  1803 * HOL/simplifier: simplification procedures nat_cancel_sums for
  1804 cancelling out common nat summands from =, <, <= (in)equalities, or
  1805 differences; simplification procedures nat_cancel_factor for
  1806 cancelling common factor from =, <, <= (in)equalities over natural
  1807 sums; nat_cancel contains both kinds of procedures, it is installed by
  1808 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  1809 
  1810 * HOL/simplifier: terms of the form
  1811   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  1812   are rewritten to
  1813   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  1814   and those of the form
  1815   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  1816   are rewritten to
  1817   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  1818 
  1819 * HOL/datatype
  1820   Each datatype `t' now comes with a theorem `split_t_case' of the form
  1821 
  1822   P(t_case f1 ... fn x) =
  1823      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  1824         ...
  1825        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  1826      )
  1827 
  1828   and a theorem `split_t_case_asm' of the form
  1829 
  1830   P(t_case f1 ... fn x) =
  1831     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  1832         ...
  1833        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  1834      )
  1835   which can be added to a simpset via `addsplits'. The existing theorems
  1836   expand_list_case and expand_option_case have been renamed to
  1837   split_list_case and split_option_case.
  1838 
  1839 * HOL/Arithmetic:
  1840   - `pred n' is automatically converted to `n-1'.
  1841     Users are strongly encouraged not to use `pred' any longer,
  1842     because it will disappear altogether at some point.
  1843   - Users are strongly encouraged to write "0 < n" rather than
  1844     "n ~= 0". Theorems and proof tools have been modified towards this
  1845     `standard'.
  1846 
  1847 * HOL/Lists:
  1848   the function "set_of_list" has been renamed "set" (and its theorems too);
  1849   the function "nth" now takes its arguments in the reverse order and
  1850   has acquired the infix notation "!" as in "xs!n".
  1851 
  1852 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  1853 
  1854 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  1855   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  1856 
  1857 * HOL/record: extensible records with schematic structural subtyping
  1858 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  1859 still lacks various theorems and concrete record syntax;
  1860 
  1861 
  1862 *** HOLCF ***
  1863 
  1864 * removed "axioms" and "generated by" sections;
  1865 
  1866 * replaced "ops" section by extended "consts" section, which is capable of
  1867   handling the continuous function space "->" directly;
  1868 
  1869 * domain package:
  1870   . proves theorems immediately and stores them in the theory,
  1871   . creates hierachical name space,
  1872   . now uses normal mixfix annotations (instead of cinfix...),
  1873   . minor changes to some names and values (for consistency),
  1874   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  1875   . separator between mutual domain defs: changed "," to "and",
  1876   . improved handling of sort constraints;  now they have to
  1877     appear on the left-hand side of the equations only;
  1878 
  1879 * fixed LAM <x,y,zs>.b syntax;
  1880 
  1881 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  1882 adm (%x. P (t x)), where P is chainfinite and t continuous;
  1883 
  1884 
  1885 *** FOL and ZF ***
  1886 
  1887 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1888   with `addloop' of the simplifier to faciliate case splitting in premises.
  1889 
  1890 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  1891 in HOL, they strip ALL and --> from proved theorems;
  1892 
  1893 
  1894 
  1895 New in Isabelle94-8 (May 1997)
  1896 ------------------------------
  1897 
  1898 *** General Changes ***
  1899 
  1900 * new utilities to build / run / maintain Isabelle etc. (in parts
  1901 still somewhat experimental); old Makefiles etc. still functional;
  1902 
  1903 * new 'Isabelle System Manual';
  1904 
  1905 * INSTALL text, together with ./configure and ./build scripts;
  1906 
  1907 * reimplemented type inference for greater efficiency, better error
  1908 messages and clean internal interface;
  1909 
  1910 * prlim command for dealing with lots of subgoals (an easier way of
  1911 setting goals_limit);
  1912 
  1913 
  1914 *** Syntax ***
  1915 
  1916 * supports alternative (named) syntax tables (parser and pretty
  1917 printer); internal interface is provided by add_modesyntax(_i);
  1918 
  1919 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  1920 be used in conjunction with the Isabelle symbol font; uses the
  1921 "symbols" syntax table;
  1922 
  1923 * added token_translation interface (may translate name tokens in
  1924 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  1925 the current print_mode); IMPORTANT: user print translation functions
  1926 are responsible for marking newly introduced bounds
  1927 (Syntax.mark_boundT);
  1928 
  1929 * token translations for modes "xterm" and "xterm_color" that display
  1930 names in bold, underline etc. or colors (which requires a color
  1931 version of xterm);
  1932 
  1933 * infixes may now be declared with names independent of their syntax;
  1934 
  1935 * added typed_print_translation (like print_translation, but may
  1936 access type of constant);
  1937 
  1938 
  1939 *** Classical Reasoner ***
  1940 
  1941 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  1942 some limitations.  Blast_tac...
  1943   + ignores addss, addbefore, addafter; this restriction is intrinsic
  1944   + ignores elimination rules that don't have the correct format
  1945         (the conclusion MUST be a formula variable)
  1946   + ignores types, which can make HOL proofs fail
  1947   + rules must not require higher-order unification, e.g. apply_type in ZF
  1948     [message "Function Var's argument not a bound variable" relates to this]
  1949   + its proof strategy is more general but can actually be slower
  1950 
  1951 * substitution with equality assumptions no longer permutes other
  1952 assumptions;
  1953 
  1954 * minor changes in semantics of addafter (now called addaltern); renamed
  1955 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  1956 (and access functions for it);
  1957 
  1958 * improved combination of classical reasoner and simplifier:
  1959   + functions for handling clasimpsets
  1960   + improvement of addss: now the simplifier is called _after_ the
  1961     safe steps.
  1962   + safe variant of addss called addSss: uses safe simplifications
  1963     _during_ the safe steps. It is more complete as it allows multiple
  1964     instantiations of unknowns (e.g. with slow_tac).
  1965 
  1966 *** Simplifier ***
  1967 
  1968 * added interface for simplification procedures (functions that
  1969 produce *proven* rewrite rules on the fly, depending on current
  1970 redex);
  1971 
  1972 * ordering on terms as parameter (used for ordered rewriting);
  1973 
  1974 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  1975 
  1976 * the solver is now split into a safe and an unsafe part.
  1977 This should be invisible for the normal user, except that the
  1978 functions setsolver and addsolver have been renamed to setSolver and
  1979 addSolver; added safe_asm_full_simp_tac;
  1980 
  1981 
  1982 *** HOL ***
  1983 
  1984 * a generic induction tactic `induct_tac' which works for all datatypes and
  1985 also for type `nat';
  1986 
  1987 * a generic case distinction tactic `exhaust_tac' which works for all
  1988 datatypes and also for type `nat';
  1989 
  1990 * each datatype comes with a function `size';
  1991 
  1992 * patterns in case expressions allow tuple patterns as arguments to
  1993 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  1994 
  1995 * primrec now also works with type nat;
  1996 
  1997 * recdef: a new declaration form, allows general recursive functions to be
  1998 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  1999 
  2000 * the constant for negation has been renamed from "not" to "Not" to
  2001 harmonize with FOL, ZF, LK, etc.;
  2002 
  2003 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  2004 infinite lists;
  2005 
  2006 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  2007 
  2008 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  2009 problems in commutative rings, using axiomatic type classes for + and *;
  2010 
  2011 * more examples in HOL/MiniML and HOL/Auth;
  2012 
  2013 * more default rewrite rules for quantifiers, union/intersection;
  2014 
  2015 * a new constant `arbitrary == @x.False';
  2016 
  2017 * HOLCF/IOA replaces old HOL/IOA;
  2018 
  2019 * HOLCF changes: derived all rules and arities
  2020   + axiomatic type classes instead of classes
  2021   + typedef instead of faking type definitions
  2022   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  2023   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  2024   + eliminated the types void, one, tr
  2025   + use unit lift and bool lift (with translations) instead of one and tr
  2026   + eliminated blift from Lift3.thy (use Def instead of blift)
  2027   all eliminated rules are derived as theorems --> no visible changes ;
  2028 
  2029 
  2030 *** ZF ***
  2031 
  2032 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  2033 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  2034 as ZF_cs addSIs [equalityI];
  2035 
  2036 
  2037 
  2038 New in Isabelle94-7 (November 96)
  2039 ---------------------------------
  2040 
  2041 * allowing negative levels (as offsets) in prlev and choplev;
  2042 
  2043 * super-linear speedup for large simplifications;
  2044 
  2045 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  2046 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  2047 FAIL); can suppress it using the command Delsimps (ex_simps @
  2048 all_simps); De Morgan laws are also now included, by default;
  2049 
  2050 * improved printing of ==>  :  ~:
  2051 
  2052 * new object-logic "Sequents" adds linear logic, while replacing LK
  2053 and Modal (thanks to Sara Kalvala);
  2054 
  2055 * HOL/Auth: correctness proofs for authentication protocols;
  2056 
  2057 * HOL: new auto_tac combines rewriting and classical reasoning (many
  2058 examples on HOL/Auth);
  2059 
  2060 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  2061 the rewriter and classical reasoner simultaneously;
  2062 
  2063 * function uresult no longer returns theorems in "standard" format;
  2064 regain previous version by: val uresult = standard o uresult;
  2065 
  2066 
  2067 
  2068 New in Isabelle94-6
  2069 -------------------
  2070 
  2071 * oracles -- these establish an interface between Isabelle and trusted
  2072 external reasoners, which may deliver results as theorems;
  2073 
  2074 * proof objects (in particular record all uses of oracles);
  2075 
  2076 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  2077 
  2078 * "constdefs" section in theory files;
  2079 
  2080 * "primrec" section (HOL) no longer requires names;
  2081 
  2082 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  2083 
  2084 
  2085 
  2086 New in Isabelle94-5
  2087 -------------------
  2088 
  2089 * reduced space requirements;
  2090 
  2091 * automatic HTML generation from theories;
  2092 
  2093 * theory files no longer require "..." (quotes) around most types;
  2094 
  2095 * new examples, including two proofs of the Church-Rosser theorem;
  2096 
  2097 * non-curried (1994) version of HOL is no longer distributed;
  2098 
  2099 
  2100 
  2101 New in Isabelle94-4
  2102 -------------------
  2103 
  2104 * greatly reduced space requirements;
  2105 
  2106 * theory files (.thy) no longer require \...\ escapes at line breaks;
  2107 
  2108 * searchable theorem database (see the section "Retrieving theorems" on
  2109 page 8 of the Reference Manual);
  2110 
  2111 * new examples, including Grabczewski's monumental case study of the
  2112 Axiom of Choice;
  2113 
  2114 * The previous version of HOL renamed to Old_HOL;
  2115 
  2116 * The new version of HOL (previously called CHOL) uses a curried syntax
  2117 for functions.  Application looks like f a b instead of f(a,b);
  2118 
  2119 * Mutually recursive inductive definitions finally work in HOL;
  2120 
  2121 * In ZF, pattern-matching on tuples is now available in all abstractions and
  2122 translates to the operator "split";
  2123 
  2124 
  2125 
  2126 New in Isabelle94-3
  2127 -------------------
  2128 
  2129 * new infix operator, addss, allowing the classical reasoner to
  2130 perform simplification at each step of its search.  Example:
  2131         fast_tac (cs addss ss)
  2132 
  2133 * a new logic, CHOL, the same as HOL, but with a curried syntax
  2134 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  2135 look like (a,b) instead of <a,b>;
  2136 
  2137 * PLEASE NOTE: CHOL will eventually replace HOL!
  2138 
  2139 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  2140 It translates to the operator "split".  A new theory of integers is available;
  2141 
  2142 * In ZF, integer numerals now denote two's-complement binary integers.
  2143 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  2144 
  2145 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  2146 of the Axiom of Choice;
  2147 
  2148 
  2149 
  2150 New in Isabelle94-2
  2151 -------------------
  2152 
  2153 * Significantly faster resolution;
  2154 
  2155 * the different sections in a .thy file can now be mixed and repeated
  2156 freely;
  2157 
  2158 * Database of theorems for FOL, HOL and ZF.  New
  2159 commands including qed, qed_goal and bind_thm store theorems in the database.
  2160 
  2161 * Simple database queries: return a named theorem (get_thm) or all theorems of
  2162 a given theory (thms_of), or find out what theory a theorem was proved in
  2163 (theory_of_thm);
  2164 
  2165 * Bugs fixed in the inductive definition and datatype packages;
  2166 
  2167 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  2168 and HOL_dup_cs obsolete;
  2169 
  2170 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  2171 have been removed;
  2172 
  2173 * Simpler definition of function space in ZF;
  2174 
  2175 * new results about cardinal and ordinal arithmetic in ZF;
  2176 
  2177 * 'subtype' facility in HOL for introducing new types as subsets of existing
  2178 types;
  2179 
  2180 
  2181 $Id$