NEWS
author wenzelm
Tue Feb 12 20:31:40 2002 +0100 (2002-02-12)
changeset 12877 b9635eb8a448
parent 12853 de505273c971
child 12889 1de4f0b824a8
permissions -rw-r--r--
* Isar/Pure: marginal comments ``--'' may now occur just anywhere in the text;
     1 
     2 Isabelle NEWS -- history user-relevant changes
     3 ==============================================
     4 
     5 New in Isabelle2002 (January 2002)
     6 ----------------------------------
     7 
     8 *** Document preparation ***
     9 
    10 * greatly simplified document preparation setup, including more
    11 graceful interpretation of isatool usedir -i/-d/-D options, and more
    12 instructive isatool mkdir; users should basically be able to get
    13 started with "isatool mkdir Test && isatool make";
    14 
    15 * theory dependency graph may now be incorporated into documents;
    16 isatool usedir -g true will produce session_graph.eps/.pdf for use
    17 with \includegraphics of LaTeX;
    18 
    19 * proper spacing of consecutive markup elements, especially text
    20 blocks after section headings;
    21 
    22 * support bold style (for single symbols only), input syntax is like
    23 this: "\<^bold>\<alpha>" or "\<^bold>A";
    24 
    25 * \<bullet> is now output as bold \cdot by default, which looks much
    26 better in printed text;
    27 
    28 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
    29 note that these symbols are currently unavailable in Proof General /
    30 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
    31 
    32 * isatool latex no longer depends on changed TEXINPUTS, instead
    33 isatool document copies the Isabelle style files to the target
    34 location;
    35 
    36 
    37 *** Isar ***
    38 
    39 * Pure/Provers: improved proof by cases and induction;
    40   - 'case' command admits impromptu naming of parameters (such as
    41     "case (Suc n)");
    42   - 'induct' method divinates rule instantiation from the inductive
    43     claim; no longer requires excessive ?P bindings for proper
    44     instantiation of cases;
    45   - 'induct' method properly enumerates all possibilities of set/type
    46     rules; as a consequence facts may be also passed through *type*
    47     rules without further ado;
    48   - 'induct' method now derives symbolic cases from the *rulified*
    49     rule (before it used to rulify cases stemming from the internal
    50     atomized version); this means that the context of a non-atomic
    51     statement becomes is included in the hypothesis, avoiding the
    52     slightly cumbersome show "PROP ?case" form;
    53   - 'induct' may now use elim-style induction rules without chaining
    54     facts, using ``missing'' premises from the goal state; this allows
    55     rules stemming from inductive sets to be applied in unstructured
    56     scripts, while still benefitting from proper handling of non-atomic
    57     statements; NB: major inductive premises need to be put first, all
    58     the rest of the goal is passed through the induction;
    59   - 'induct' proper support for mutual induction involving non-atomic
    60     rule statements (uses the new concept of simultaneous goals, see
    61     below);
    62   - append all possible rule selections, but only use the first
    63     success (no backtracking);
    64   - removed obsolete "(simplified)" and "(stripped)" options of methods;
    65   - undeclared rule case names default to numbers 1, 2, 3, ...;
    66   - added 'print_induct_rules' (covered by help item in recent Proof
    67     General versions);
    68   - moved induct/cases attributes to Pure, methods to Provers;
    69   - generic method setup instantiated for FOL and HOL;
    70 
    71 * Pure: support multiple simultaneous goal statements, for example
    72 "have a: A and b: B" (same for 'theorem' etc.); being a pure
    73 meta-level mechanism, this acts as if several individual goals had
    74 been stated separately; in particular common proof methods need to be
    75 repeated in order to cover all claims; note that a single elimination
    76 step is *not* sufficient to establish the two conjunctions, so this
    77 fails:
    78 
    79   assume "A & B" then have A and B ..   (*".." fails*)
    80 
    81 better use "obtain" in situations as above; alternative refer to
    82 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
    83 
    84 * Pure: proper integration with ``locales''; unlike the original
    85 version by Florian Kammüller, Isar locales package high-level proof
    86 contexts rather than raw logical ones (e.g. we admit to include
    87 attributes everywhere); operations on locales include merge and
    88 rename; e.g. see HOL/ex/Locales.thy;
    89 
    90 * Pure: the following commands have been ``localized'', supporting a
    91 target locale specification "(in name)": 'lemma', 'theorem',
    92 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
    93 stored both within the locale and at the theory level (exported and
    94 qualified by the locale name);
    95 
    96 * Pure: theory goals now support ad-hoc contexts, which are discharged
    97 in the result, as in ``lemma (assumes A and B) K: A .''; syntax
    98 coincides with that of a locale body;
    99 
   100 * Pure: renamed "antecedent" case to "rule_context";
   101 
   102 * Pure: added 'corollary' command;
   103 
   104 * Pure: fixed 'token_translation' command;
   105 
   106 * Pure: removed obsolete 'exported' attribute;
   107 
   108 * Pure: dummy pattern "_" in is/let is now automatically lifted over
   109 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
   110 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
   111 
   112 * Pure: method 'atomize' presents local goal premises as object-level
   113 statements (atomic meta-level propositions); setup controlled via
   114 rewrite rules declarations of 'atomize' attribute; example
   115 application: 'induct' method with proper rule statements in improper
   116 proof *scripts*;
   117 
   118 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
   119 now consider the syntactic context of assumptions, giving a better
   120 chance to get type-inference of the arguments right (this is
   121 especially important for locales);
   122 
   123 * Pure: "sorry" no longer requires quick_and_dirty in interactive
   124 mode;
   125 
   126 * Pure/obtain: the formal conclusion "thesis", being marked as
   127 ``internal'', may no longer be reference directly in the text;
   128 potential INCOMPATIBILITY, may need to use "?thesis" in rare
   129 situations;
   130 
   131 * Pure: generic 'sym' attribute which declares a rule both as pure
   132 'elim?' and for the 'symmetric' operation;
   133 
   134 * Pure: marginal comments ``--'' may now occur just anywhere in the
   135 text; the fixed correlation with particular command syntax has been
   136 discontinued;
   137 
   138 * Pure/Provers/classical: simplified integration with pure rule
   139 attributes and methods; the classical "intro?/elim?/dest?"
   140 declarations coincide with the pure ones; the "rule" method no longer
   141 includes classically swapped intros; "intro" and "elim" methods no
   142 longer pick rules from the context; also got rid of ML declarations
   143 AddXIs/AddXEs/AddXDs; all of this has some potential for
   144 INCOMPATIBILITY;
   145 
   146 * Provers/classical: attribute 'swapped' produces classical inversions
   147 of introduction rules;
   148 
   149 * Provers/simplifier: 'simplified' attribute may refer to explicit
   150 rules instead of full simplifier context; 'iff' attribute handles
   151 conditional rules;
   152 
   153 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
   154 
   155 * HOL: 'recdef' now fails on unfinished automated proofs, use
   156 "(permissive)" option to recover old behavior;
   157 
   158 * HOL: 'inductive' no longer features separate (collective) attributes
   159 for 'intros' (was found too confusing);
   160 
   161 * HOL: properly declared induction rules less_induct and
   162 wf_induct_rule;
   163 
   164 
   165 *** HOL ***
   166 
   167 * HOL: moved over to sane numeral syntax; the new policy is as
   168 follows:
   169 
   170   - 0 and 1 are polymorphic constants, which are defined on any
   171   numeric type (nat, int, real etc.);
   172 
   173   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
   174   binary representation internally;
   175 
   176   - type nat has special constructor Suc, and generally prefers Suc 0
   177   over 1::nat and Suc (Suc 0) over 2::nat;
   178 
   179 This change may cause significant problems of INCOMPATIBILITY; here
   180 are some hints on converting existing sources:
   181 
   182   - due to the new "num" token, "-0" and "-1" etc. are now atomic
   183   entities, so expressions involving "-" (unary or binary minus) need
   184   to be spaced properly;
   185 
   186   - existing occurrences of "1" may need to be constraint "1::nat" or
   187   even replaced by Suc 0; similar for old "2";
   188 
   189   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
   190 
   191   - remove all special provisions on numerals in proofs;
   192 
   193 * HOL: simp rules nat_number_of expand numerals on nat to Suc/0
   194 representation (depends on bin_arith_simps in the default context);
   195 
   196 * HOL: symbolic syntax for x^2 (numeral 2);
   197 
   198 * HOL: the class of all HOL types is now called "type" rather than
   199 "term"; INCOMPATIBILITY, need to adapt references to this type class
   200 in axclass/classes, instance/arities, and (usually rare) occurrences
   201 in typings (of consts etc.); internally the class is called
   202 "HOL.type", ML programs should refer to HOLogic.typeS;
   203 
   204 * HOL/record package improvements:
   205   - new derived operations "fields" to build a partial record section,
   206     "extend" to promote a fixed record to a record scheme, and
   207     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
   208     declared as simp by default;
   209   - shared operations ("more", "fields", etc.) now need to be always
   210     qualified) --- potential INCOMPATIBILITY;
   211   - removed "make_scheme" operations (use "make" with "extend") --
   212     INCOMPATIBILITY;
   213   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
   214   - provides cases/induct rules for use with corresponding Isar
   215     methods (for concrete records, record schemes, concrete more
   216     parts, and schematic more parts -- in that order);
   217   - internal definitions directly based on a light-weight abstract
   218     theory of product types over typedef rather than datatype;
   219 
   220 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
   221 
   222 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
   223 (beware of argument permutation!);
   224 
   225 * HOL: linorder_less_split superseded by linorder_cases;
   226 
   227 * HOL: added "The" definite description operator; move Hilbert's "Eps"
   228 to peripheral theory "Hilbert_Choice";
   229 
   230 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
   231 in this (rare) case use:
   232 
   233   delSWrapper "split_all_tac"
   234   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
   235 
   236 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
   237 MAY FAIL;
   238 
   239 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
   240 Isabelle's type classes, ^ on functions and relations has too general
   241 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
   242 necessary to attach explicit type constraints;
   243 
   244 * HOL/Relation: the prefix name of the infix "O" has been changed from "comp"
   245 to "rel_comp"; INCOMPATIBILITY: a few theorems have been renamed accordingly
   246 (eg "compI" -> "rel_compI").
   247 
   248 * HOL: syntax translations now work properly with numerals and records
   249 expressions;
   250 
   251 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
   252 of "lam" -- INCOMPATIBILITY;
   253 
   254 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
   255 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
   256 renamed "Product_Type.unit";
   257 
   258 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
   259 
   260 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
   261 Florian Kammüller);
   262 
   263 * HOL/IMP: updated and converted to new-style theory format; several
   264 parts turned into readable document, with proper Isar proof texts and
   265 some explanations (by Gerwin Klein);
   266 
   267 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
   268 
   269 * HOL-Hyperreal is now a logic image;
   270 
   271 
   272 *** HOLCF ***
   273 
   274 * Isar: consts/constdefs supports mixfix syntax for continuous
   275 operations;
   276 
   277 * Isar: domain package adapted to new-style theory format, e.g. see
   278 HOLCF/ex/Dnat.thy;
   279 
   280 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
   281 potential INCOMPATIBILITY; now use plain induct_tac instead of former
   282 lift.induct_tac, always use UU instead of Undef;
   283 
   284 * HOLCF/IMP: updated and converted to new-style theory;
   285 
   286 
   287 *** ZF ***
   288 
   289 * Isar: proper integration of logic-specific tools and packages,
   290 including theory commands '(co)inductive', '(co)datatype',
   291 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
   292 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
   293 
   294 * theory Main no longer includes AC; for the Axiom of Choice, base
   295 your theory on Main_ZFC;
   296 
   297 * the integer library now covers quotients and remainders, with many
   298 laws relating division to addition, multiplication, etc.;
   299 
   300 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
   301 typeless version of the formalism;
   302 
   303 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory format;
   304 
   305 * ZF/Induct: new directory for examples of inductive definitions,
   306 including theory Multiset for multiset orderings; converted to
   307 new-style theory format;
   308 
   309 * Many new theorems about lists, ordinals, etc.;
   310 
   311 
   312 *** General ***
   313 
   314 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
   315 variable proof controls level of detail: 0 = no proofs (only oracle
   316 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
   317 also ref manual for further ML interfaces;
   318 
   319 * Pure/axclass: removed obsolete ML interface
   320 goal_subclass/goal_arity;
   321 
   322 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
   323 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
   324 separate tokens, so expressions involving minus need to be spaced
   325 properly;
   326 
   327 * Pure/syntax: support non-oriented infixes, using keyword "infix"
   328 rather than "infixl" or "infixr";
   329 
   330 * Pure/syntax: concrete syntax for dummy type variables admits genuine
   331 sort constraint specifications in type inference; e.g. "x::_::foo"
   332 ensures that the type of "x" is of sort "foo" (but not necessarily a
   333 type variable);
   334 
   335 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
   336 control output of nested => (types); the default behavior is
   337 "type_brackets";
   338 
   339 * Pure/syntax: builtin parse translation for "_constify" turns valued
   340 tokens into AST constants;
   341 
   342 * Pure/syntax: prefer later declarations of translations and print
   343 translation functions; potential INCOMPATIBILITY: need to reverse
   344 multiple declarations for same syntax element constant;
   345 
   346 * Pure/show_hyps reset by default (in accordance to existing Isar
   347 practice);
   348 
   349 * Provers/classical: renamed addaltern to addafter, addSaltern to
   350 addSafter;
   351 
   352 * Provers/clasimp: ``iff'' declarations now handle conditional rules
   353 as well;
   354 
   355 * system: tested support for MacOS X; should be able to get Isabelle +
   356 Proof General to work in a plain Terminal after installing Poly/ML
   357 (e.g. from the Isabelle distribution area) and GNU bash alone
   358 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
   359 support requires further installations, e.g. from
   360 http://fink.sourceforge.net/);
   361 
   362 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
   363 
   364 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
   365 of 40 MB), cf. ML_OPTIONS;
   366 
   367 * system: Proof General keywords specification is now part of the
   368 Isabelle distribution (see etc/isar-keywords.el);
   369 
   370 * system: support for persistent Proof General sessions (refrain from
   371 outdating all loaded theories on startup); user may create writable
   372 logic images like this: ``isabelle -q HOL Test'';
   373 
   374 * system: smart selection of Isabelle process versus Isabelle
   375 interface, accommodates case-insensitive file systems (e.g. HFS+); may
   376 run both "isabelle" and "Isabelle" even if file names are badly
   377 damaged (executable inspects the case of the first letter of its own
   378 name); added separate "isabelle-process" and "isabelle-interface";
   379 
   380 * system: refrain from any attempt at filtering input streams; no
   381 longer support ``8bit'' encoding of old isabelle font, instead proper
   382 iso-latin characters may now be used; the related isatools
   383 "symbolinput" and "nonascii" have disappeared as well;
   384 
   385 * system: removed old "xterm" interface (the print modes "xterm" and
   386 "xterm_color" are still available for direct use in a suitable
   387 terminal);
   388 
   389 
   390 
   391 New in Isabelle99-2 (February 2001)
   392 -----------------------------------
   393 
   394 *** Overview of INCOMPATIBILITIES ***
   395 
   396 * HOL: please note that theories in the Library and elsewhere often use the
   397 new-style (Isar) format; to refer to their theorems in an ML script you must
   398 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
   399 
   400 * HOL: inductive package no longer splits induction rule aggressively,
   401 but only as far as specified by the introductions given; the old
   402 format may be recovered via ML function complete_split_rule or attribute
   403 'split_rule (complete)';
   404 
   405 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
   406 gfp_Tarski to gfp_unfold;
   407 
   408 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
   409 
   410 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
   411 relation); infix "^^" has been renamed "``"; infix "``" has been
   412 renamed "`"; "univalent" has been renamed "single_valued";
   413 
   414 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
   415 operation;
   416 
   417 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
   418 
   419 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
   420 
   421 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
   422 consequence, it is no longer monotonic wrt. the local goal context
   423 (which is now passed through the inductive cases);
   424 
   425 * Document preparation: renamed standard symbols \<ll> to \<lless> and
   426 \<gg> to \<ggreater>;
   427 
   428 
   429 *** Document preparation ***
   430 
   431 * \isabellestyle{NAME} selects version of Isabelle output (currently
   432 available: are "it" for near math-mode best-style output, "sl" for
   433 slanted text style, and "tt" for plain type-writer; if no
   434 \isabellestyle command is given, output is according to slanted
   435 type-writer);
   436 
   437 * support sub/super scripts (for single symbols only), input syntax is
   438 like this: "A\<^sup>*" or "A\<^sup>\<star>";
   439 
   440 * some more standard symbols; see Appendix A of the system manual for
   441 the complete list of symbols defined in isabellesym.sty;
   442 
   443 * improved isabelle style files; more abstract symbol implementation
   444 (should now use \isamath{...} and \isatext{...} in custom symbol
   445 definitions);
   446 
   447 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
   448 state; Note that presentation of goal states does not conform to
   449 actual human-readable proof documents.  Please do not include goal
   450 states into document output unless you really know what you are doing!
   451 
   452 * proper indentation of antiquoted output with proportional LaTeX
   453 fonts;
   454 
   455 * no_document ML operator temporarily disables LaTeX document
   456 generation;
   457 
   458 * isatool unsymbolize tunes sources for plain ASCII communication;
   459 
   460 
   461 *** Isar ***
   462 
   463 * Pure: Isar now suffers initial goal statements to contain unbound
   464 schematic variables (this does not conform to actual readable proof
   465 documents, due to unpredictable outcome and non-compositional proof
   466 checking); users who know what they are doing may use schematic goals
   467 for Prolog-style synthesis of proven results;
   468 
   469 * Pure: assumption method (an implicit finishing) now handles actual
   470 rules as well;
   471 
   472 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
   473 initial goal, declare "that" only as Pure intro (only for single
   474 steps); the "that" rule assumption may now be involved in implicit
   475 finishing, thus ".." becomes a feasible for trivial obtains;
   476 
   477 * Pure: default proof step now includes 'intro_classes'; thus trivial
   478 instance proofs may be performed by "..";
   479 
   480 * Pure: ?thesis / ?this / "..." now work for pure meta-level
   481 statements as well;
   482 
   483 * Pure: more robust selection of calculational rules;
   484 
   485 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
   486 rule (as well as the assumption rule);
   487 
   488 * Pure: 'thm_deps' command visualizes dependencies of theorems and
   489 lemmas, using the graph browser tool;
   490 
   491 * Pure: predict failure of "show" in interactive mode;
   492 
   493 * Pure: 'thms_containing' now takes actual terms as arguments;
   494 
   495 * HOL: improved method 'induct' --- now handles non-atomic goals
   496 (potential INCOMPATIBILITY); tuned error handling;
   497 
   498 * HOL: cases and induct rules now provide explicit hints about the
   499 number of facts to be consumed (0 for "type" and 1 for "set" rules);
   500 any remaining facts are inserted into the goal verbatim;
   501 
   502 * HOL: local contexts (aka cases) may now contain term bindings as
   503 well; the 'cases' and 'induct' methods new provide a ?case binding for
   504 the result to be shown in each case;
   505 
   506 * HOL: added 'recdef_tc' command;
   507 
   508 * isatool convert assists in eliminating legacy ML scripts;
   509 
   510 
   511 *** HOL ***
   512 
   513 * HOL/Library: a collection of generic theories to be used together
   514 with main HOL; the theory loader path already includes this directory
   515 by default; the following existing theories have been moved here:
   516 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
   517 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
   518 
   519 * HOL/Unix: "Some aspects of Unix file-system security", a typical
   520 modelling and verification task performed in Isabelle/HOL +
   521 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
   522 
   523 * HOL/Algebra: special summation operator SUM no longer exists, it has
   524 been replaced by setsum; infix 'assoc' now has priority 50 (like
   525 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
   526 'domain', this makes the theory consistent with mathematical
   527 literature;
   528 
   529 * HOL basics: added overloaded operations "inverse" and "divide"
   530 (infix "/"), syntax for generic "abs" operation, generic summation
   531 operator \<Sum>;
   532 
   533 * HOL/typedef: simplified package, provide more useful rules (see also
   534 HOL/subset.thy);
   535 
   536 * HOL/datatype: induction rule for arbitrarily branching datatypes is
   537 now expressed as a proper nested rule (old-style tactic scripts may
   538 require atomize_strip_tac to cope with non-atomic premises);
   539 
   540 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
   541 to "split_conv" (old name still available for compatibility);
   542 
   543 * HOL: improved concrete syntax for strings (e.g. allows translation
   544 rules with string literals);
   545 
   546 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
   547  and Fleuriot's mechanization of analysis, including the transcendental
   548  functions for the reals;
   549 
   550 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
   551 
   552 
   553 *** CTT ***
   554 
   555 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
   556 "lam" is displayed as TWO lambda-symbols
   557 
   558 * CTT: theory Main now available, containing everything (that is, Bool
   559 and Arith);
   560 
   561 
   562 *** General ***
   563 
   564 * Pure: the Simplifier has been implemented properly as a derived rule
   565 outside of the actual kernel (at last!); the overall performance
   566 penalty in practical applications is about 50%, while reliability of
   567 the Isabelle inference kernel has been greatly improved;
   568 
   569 * print modes "brackets" and "no_brackets" control output of nested =>
   570 (types) and ==> (props); the default behaviour is "brackets";
   571 
   572 * Provers: fast_tac (and friends) now handle actual object-logic rules
   573 as assumptions as well;
   574 
   575 * system: support Poly/ML 4.0;
   576 
   577 * system: isatool install handles KDE version 1 or 2;
   578 
   579 
   580 
   581 New in Isabelle99-1 (October 2000)
   582 ----------------------------------
   583 
   584 *** Overview of INCOMPATIBILITIES ***
   585 
   586 * HOL: simplification of natural numbers is much changed; to partly
   587 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
   588 issue the following ML commands:
   589 
   590   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
   591   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
   592 
   593 * HOL: simplification no longer dives into case-expressions; this is
   594 controlled by "t.weak_case_cong" for each datatype t;
   595 
   596 * HOL: nat_less_induct renamed to less_induct;
   597 
   598 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
   599 fixsome to patch .thy and .ML sources automatically;
   600 
   601   select_equality  -> some_equality
   602   select_eq_Ex     -> some_eq_ex
   603   selectI2EX       -> someI2_ex
   604   selectI2         -> someI2
   605   selectI          -> someI
   606   select1_equality -> some1_equality
   607   Eps_sym_eq       -> some_sym_eq_trivial
   608   Eps_eq           -> some_eq_trivial
   609 
   610 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
   611 
   612 * HOL: removed obsolete theorem binding expand_if (refer to split_if
   613 instead);
   614 
   615 * HOL: the recursion equations generated by 'recdef' are now called
   616 f.simps instead of f.rules;
   617 
   618 * HOL: qed_spec_mp now also handles bounded ALL as well;
   619 
   620 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
   621 sometimes be needed;
   622 
   623 * HOL: the constant for "f``x" is now "image" rather than "op ``";
   624 
   625 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
   626 
   627 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
   628 product is now "<*>" instead of "Times"; the lexicographic product is
   629 now "<*lex*>" instead of "**";
   630 
   631 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
   632 of main HOL, but was unused); better use HOL's datatype package;
   633 
   634 * HOL: removed "symbols" syntax for constant "override" of theory Map;
   635 the old syntax may be recovered as follows:
   636 
   637   syntax (symbols)
   638     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
   639       (infixl "\\<oplus>" 100)
   640 
   641 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   642 
   643 * HOL/ML: even fewer consts are declared as global (see theories Ord,
   644 Lfp, Gfp, WF); this only affects ML packages that refer to const names
   645 internally;
   646 
   647 * HOL and ZF: syntax for quotienting wrt an equivalence relation
   648 changed from A/r to A//r;
   649 
   650 * ZF: new treatment of arithmetic (nat & int) may break some old
   651 proofs;
   652 
   653 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
   654 rulify -> rule_format, elimify -> elim_format, ...);
   655 
   656 * Isar/Provers: intro/elim/dest attributes changed; renamed
   657 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
   658 should have to change intro!! to intro? only); replaced "delrule" by
   659 "rule del";
   660 
   661 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
   662 
   663 * Provers: strengthened force_tac by using new first_best_tac;
   664 
   665 * LaTeX document preparation: several changes of isabelle.sty (see
   666 lib/texinputs);
   667 
   668 
   669 *** Document preparation ***
   670 
   671 * formal comments (text blocks etc.) in new-style theories may now
   672 contain antiquotations of thm/prop/term/typ/text to be presented
   673 according to latex print mode; concrete syntax is like this:
   674 @{term[show_types] "f(x) = a + x"};
   675 
   676 * isatool mkdir provides easy setup of Isabelle session directories,
   677 including proper document sources;
   678 
   679 * generated LaTeX sources are now deleted after successful run
   680 (isatool document -c); may retain a copy somewhere else via -D option
   681 of isatool usedir;
   682 
   683 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
   684 style files, achieving self-contained LaTeX sources and simplifying
   685 LaTeX debugging;
   686 
   687 * old-style theories now produce (crude) LaTeX output as well;
   688 
   689 * browser info session directories are now self-contained (may be put
   690 on WWW server seperately); improved graphs of nested sessions; removed
   691 graph for 'all sessions';
   692 
   693 * several improvements in isabelle style files; \isabellestyle{it}
   694 produces fake math mode output; \isamarkupheader is now \section by
   695 default; see lib/texinputs/isabelle.sty etc.;
   696 
   697 
   698 *** Isar ***
   699 
   700 * Isar/Pure: local results and corresponding term bindings are now
   701 subject to Hindley-Milner polymorphism (similar to ML); this
   702 accommodates incremental type-inference very nicely;
   703 
   704 * Isar/Pure: new derived language element 'obtain' supports
   705 generalized existence reasoning;
   706 
   707 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
   708 support accumulation of results, without applying any rules yet;
   709 useful to collect intermediate results without explicit name
   710 references, and for use with transitivity rules with more than 2
   711 premises;
   712 
   713 * Isar/Pure: scalable support for case-analysis type proofs: new
   714 'case' language element refers to local contexts symbolically, as
   715 produced by certain proof methods; internally, case names are attached
   716 to theorems as "tags";
   717 
   718 * Isar/Pure: theory command 'hide' removes declarations from
   719 class/type/const name spaces;
   720 
   721 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
   722 indicate potential overloading;
   723 
   724 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
   725 
   726 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
   727 "{a,b,c}" instead of {a,b,c};
   728 
   729 * Isar/Pure now provides its own version of intro/elim/dest
   730 attributes; useful for building new logics, but beware of confusion
   731 with the version in Provers/classical;
   732 
   733 * Isar/Pure: the local context of (non-atomic) goals is provided via
   734 case name 'antecedent';
   735 
   736 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
   737 to the current context is now done automatically);
   738 
   739 * Isar/Pure: theory command 'method_setup' provides a simple interface
   740 for definining proof methods in ML;
   741 
   742 * Isar/Provers: intro/elim/dest attributes changed; renamed
   743 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
   744 most cases, one should have to change intro!! to intro? only);
   745 replaced "delrule" by "rule del";
   746 
   747 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
   748 'symmetric' attribute (the latter supercedes [RS sym]);
   749 
   750 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
   751 method modifier); 'simp' method: 'only:' modifier removes loopers as
   752 well (including splits);
   753 
   754 * Isar/Provers: Simplifier and Classical methods now support all kind
   755 of modifiers used in the past, including 'cong', 'iff', etc.
   756 
   757 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
   758 of Simplifier and Classical reasoner);
   759 
   760 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
   761 now support named cases; major packages (inductive, datatype, primrec,
   762 recdef) support case names and properly name parameters;
   763 
   764 * Isar/HOL: new transitivity rules for substitution in inequalities --
   765 monotonicity conditions are extracted to be proven at end of
   766 calculations;
   767 
   768 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
   769 method anyway;
   770 
   771 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
   772 split_if split_if_asm; datatype package provides theorems foo.splits =
   773 foo.split foo.split_asm for each datatype;
   774 
   775 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
   776 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
   777 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
   778 use "(cases (simplified))" method in proper proof texts);
   779 
   780 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
   781 
   782 * Isar: names of theorems etc. may be natural numbers as well;
   783 
   784 * Isar: 'pr' command: optional arguments for goals_limit and
   785 ProofContext.prems_limit; no longer prints theory contexts, but only
   786 proof states;
   787 
   788 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
   789 additional print modes to be specified; e.g. "pr(latex)" will print
   790 proof state according to the Isabelle LaTeX style;
   791 
   792 * Isar: improved support for emulating tactic scripts, including proof
   793 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
   794 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
   795 (for HOL datatypes);
   796 
   797 * Isar: simplified (more robust) goal selection of proof methods: 1st
   798 goal, all goals, or explicit goal specifier (tactic emulation); thus
   799 'proof method scripts' have to be in depth-first order;
   800 
   801 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
   802 
   803 * Isar: removed 'help' command, which hasn't been too helpful anyway;
   804 should instead use individual commands for printing items
   805 (print_commands, print_methods etc.);
   806 
   807 * Isar: added 'nothing' --- the empty list of theorems;
   808 
   809 
   810 *** HOL ***
   811 
   812 * HOL/MicroJava: formalization of a fragment of Java, together with a
   813 corresponding virtual machine and a specification of its bytecode
   814 verifier and a lightweight bytecode verifier, including proofs of
   815 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
   816 Cornelia Pusch (see also the homepage of project Bali at
   817 http://isabelle.in.tum.de/Bali/);
   818 
   819 * HOL/Algebra: new theory of rings and univariate polynomials, by
   820 Clemens Ballarin;
   821 
   822 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
   823 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
   824 Rasmussen;
   825 
   826 * HOL/Lattice: fundamental concepts of lattice theory and order
   827 structures, including duals, properties of bounds versus algebraic
   828 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
   829 Theorem for complete lattices etc.; may also serve as a demonstration
   830 for abstract algebraic reasoning using axiomatic type classes, and
   831 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
   832 
   833 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
   834 von Oheimb;
   835 
   836 * HOL/IMPP: extension of IMP with local variables and mutually
   837 recursive procedures, by David von Oheimb;
   838 
   839 * HOL/Lambda: converted into new-style theory and document;
   840 
   841 * HOL/ex/Multiquote: example of multiple nested quotations and
   842 anti-quotations -- basically a generalized version of de-Bruijn
   843 representation; very useful in avoiding lifting of operations;
   844 
   845 * HOL/record: added general record equality rule to simpset; fixed
   846 select-update simplification procedure to handle extended records as
   847 well; admit "r" as field name;
   848 
   849 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
   850 other numeric types and also as the identity of groups, rings, etc.;
   851 
   852 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
   853 Types nat and int belong to this axclass;
   854 
   855 * HOL: greatly improved simplification involving numerals of type nat, int, real:
   856    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
   857    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
   858   two terms #m*u and #n*u are replaced by #(m+n)*u
   859     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
   860   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
   861     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
   862 
   863 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
   864 powerful prover for predicate logic but knows nothing of clasets; see
   865 ex/mesontest.ML and ex/mesontest2.ML for example applications;
   866 
   867 * HOL: new version of "case_tac" subsumes both boolean case split and
   868 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
   869 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
   870 
   871 * HOL: simplification no longer dives into case-expressions: only the
   872 selector expression is simplified, but not the remaining arms; to
   873 enable full simplification of case-expressions for datatype t, you may
   874 remove t.weak_case_cong from the simpset, either globally (Delcongs
   875 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
   876 
   877 * HOL/recdef: the recursion equations generated by 'recdef' for
   878 function 'f' are now called f.simps instead of f.rules; if all
   879 termination conditions are proved automatically, these simplification
   880 rules are added to the simpset, as in primrec; rules may be named
   881 individually as well, resulting in a separate list of theorems for
   882 each equation;
   883 
   884 * HOL/While is a new theory that provides a while-combinator. It
   885 permits the definition of tail-recursive functions without the
   886 provision of a termination measure. The latter is necessary once the
   887 invariant proof rule for while is applied.
   888 
   889 * HOL: new (overloaded) notation for the set of elements below/above
   890 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
   891 
   892 * HOL: theorems impI, allI, ballI bound as "strip";
   893 
   894 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
   895 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
   896 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
   897 
   898 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   899 
   900 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
   901 main HOL, but was unused);
   902 
   903 * HOL: fewer consts declared as global (e.g. have to refer to
   904 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
   905 
   906 * HOL: tuned AST representation of nested pairs, avoiding bogus output
   907 in case of overlap with user translations (e.g. judgements over
   908 tuples); (note that the underlying logical represenation is still
   909 bogus);
   910 
   911 
   912 *** ZF ***
   913 
   914 * ZF: simplification automatically cancels common terms in arithmetic
   915 expressions over nat and int;
   916 
   917 * ZF: new treatment of nat to minimize type-checking: all operators
   918 coerce their operands to a natural number using the function natify,
   919 making the algebraic laws unconditional;
   920 
   921 * ZF: as above, for int: operators coerce their operands to an integer
   922 using the function intify;
   923 
   924 * ZF: the integer library now contains many of the usual laws for the
   925 orderings, including $<=, and monotonicity laws for $+ and $*;
   926 
   927 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
   928 simplification;
   929 
   930 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
   931 to the simplifier and classical reasoner simultaneously;
   932 
   933 
   934 *** General ***
   935 
   936 * Provers: blast_tac now handles actual object-logic rules as
   937 assumptions; note that auto_tac uses blast_tac internally as well;
   938 
   939 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
   940 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
   941 
   942 * Provers: delrules now handles destruct rules as well (no longer need
   943 explicit make_elim);
   944 
   945 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
   946   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   947 use instead the strong form,
   948   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   949 in HOL, FOL and ZF the function cla_make_elim will create such rules
   950 from destruct-rules;
   951 
   952 * Provers: Simplifier.easy_setup provides a fast path to basic
   953 Simplifier setup for new object-logics;
   954 
   955 * Pure: AST translation rules no longer require constant head on LHS;
   956 
   957 * Pure: improved name spaces: ambiguous output is qualified; support
   958 for hiding of names;
   959 
   960 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
   961 XSYMBOL_HOME; no longer need to do manual configuration in most
   962 situations;
   963 
   964 * system: compression of ML heaps images may now be controlled via -c
   965 option of isabelle and isatool usedir (currently only observed by
   966 Poly/ML);
   967 
   968 * system: isatool installfonts may handle X-Symbol fonts as well (very
   969 useful for remote X11);
   970 
   971 * system: provide TAGS file for Isabelle sources;
   972 
   973 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
   974 order;
   975 
   976 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
   977 timing flag supersedes proof_timing and Toplevel.trace;
   978 
   979 * ML: new combinators |>> and |>>> for incremental transformations
   980 with secondary results (e.g. certain theory extensions):
   981 
   982 * ML: PureThy.add_defs gets additional argument to indicate potential
   983 overloading (usually false);
   984 
   985 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
   986 results;
   987 
   988 
   989 
   990 New in Isabelle99 (October 1999)
   991 --------------------------------
   992 
   993 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   994 
   995 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
   996 are no longer simplified.  (This allows the simplifier to unfold recursive
   997 functional programs.)  To restore the old behaviour, declare
   998 
   999     Delcongs [if_weak_cong];
  1000 
  1001 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  1002 complement;
  1003 
  1004 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  1005 
  1006 * HOL/datatype: mutual_induct_tac no longer exists --
  1007   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  1008 
  1009 * HOL/typedef: fixed type inference for representing set; type
  1010 arguments now have to occur explicitly on the rhs as type constraints;
  1011 
  1012 * ZF: The con_defs part of an inductive definition may no longer refer
  1013 to constants declared in the same theory;
  1014 
  1015 * HOL, ZF: the function mk_cases, generated by the inductive
  1016 definition package, has lost an argument.  To simplify its result, it
  1017 uses the default simpset instead of a supplied list of theorems.
  1018 
  1019 * HOL/List: the constructors of type list are now Nil and Cons;
  1020 
  1021 * Simplifier: the type of the infix ML functions
  1022         setSSolver addSSolver setSolver addSolver
  1023 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  1024 for packaging solvers. A solver is created via
  1025         mk_solver: string -> (thm list -> int -> tactic) -> solver
  1026 where the string argument is only a comment.
  1027 
  1028 
  1029 *** Proof tools ***
  1030 
  1031 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  1032 decision procedure for linear arithmetic. Currently it is used for
  1033 types `nat', `int', and `real' in HOL (see below); it can, should and
  1034 will be instantiated for other types and logics as well.
  1035 
  1036 * The simplifier now accepts rewrite rules with flexible heads, eg
  1037      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  1038   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  1039   matching.
  1040 
  1041 
  1042 *** General ***
  1043 
  1044 * New Isabelle/Isar subsystem provides an alternative to traditional
  1045 tactical theorem proving; together with the ProofGeneral/isar user
  1046 interface it offers an interactive environment for developing human
  1047 readable proof documents (Isar == Intelligible semi-automated
  1048 reasoning); for further information see isatool doc isar-ref,
  1049 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  1050 
  1051 * improved and simplified presentation of theories: better HTML markup
  1052 (including colors), graph views in several sizes; isatool usedir now
  1053 provides a proper interface for user theories (via -P option); actual
  1054 document preparation based on (PDF)LaTeX is available as well (for
  1055 new-style theories only); see isatool doc system for more information;
  1056 
  1057 * native support for Proof General, both for classic Isabelle and
  1058 Isabelle/Isar;
  1059 
  1060 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  1061 using the graph browser tool;
  1062 
  1063 * Isabelle manuals now also available as PDF;
  1064 
  1065 * theory loader rewritten from scratch (may not be fully
  1066 bug-compatible); old loadpath variable has been replaced by show_path,
  1067 add_path, del_path, reset_path functions; new operations such as
  1068 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  1069 isatool doc ref);
  1070 
  1071 * improved isatool install: option -k creates KDE application icon,
  1072 option -p DIR installs standalone binaries;
  1073 
  1074 * added ML_PLATFORM setting (useful for cross-platform installations);
  1075 more robust handling of platform specific ML images for SML/NJ;
  1076 
  1077 * the settings environment is now statically scoped, i.e. it is never
  1078 created again in sub-processes invoked from isabelle, isatool, or
  1079 Isabelle;
  1080 
  1081 * path element specification '~~' refers to '$ISABELLE_HOME';
  1082 
  1083 * in locales, the "assumes" and "defines" parts may be omitted if
  1084 empty;
  1085 
  1086 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  1087 long arrows);
  1088 
  1089 * new print_mode "HTML";
  1090 
  1091 * new flag show_tags controls display of tags of theorems (which are
  1092 basically just comments that may be attached by some tools);
  1093 
  1094 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  1095 mode and goal output format:
  1096 
  1097 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  1098 244c244
  1099 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  1100 ---
  1101 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  1102 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  1103 181c181
  1104 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  1105 ---
  1106 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  1107 
  1108 * function bind_thms stores lists of theorems (cf. bind_thm);
  1109 
  1110 * new shorthand tactics ftac, eatac, datac, fatac;
  1111 
  1112 * qed (and friends) now accept "" as result name; in that case the
  1113 theorem is not stored, but proper checks and presentation of the
  1114 result still apply;
  1115 
  1116 * theorem database now also indexes constants "Trueprop", "all",
  1117 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  1118 
  1119 
  1120 *** HOL ***
  1121 
  1122 ** HOL arithmetic **
  1123 
  1124 * There are now decision procedures for linear arithmetic over nat and
  1125 int:
  1126 
  1127 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  1128 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  1129 are treated as atomic; subformulae not involving type `nat' or `int'
  1130 are ignored; quantified subformulae are ignored unless they are
  1131 positive universal or negative existential. The tactic has to be
  1132 invoked by hand and can be a little bit slow. In particular, the
  1133 running time is exponential in the number of occurrences of `min' and
  1134 `max', and `-' on `nat'.
  1135 
  1136 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  1137 (negated) (in)equalities among the premises and the conclusion into
  1138 account (i.e. no compound formulae) and does not know about `min' and
  1139 `max', and `-' on `nat'. It is fast and is used automatically by the
  1140 simplifier.
  1141 
  1142 NB: At the moment, these decision procedures do not cope with mixed
  1143 nat/int formulae where the two parts interact, such as `m < n ==>
  1144 int(m) < int(n)'.
  1145 
  1146 * HOL/Numeral provides a generic theory of numerals (encoded
  1147 efficiently as bit strings); setup for types nat/int/real is in place;
  1148 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  1149 int, existing theories and proof scripts may require a few additional
  1150 type constraints;
  1151 
  1152 * integer division and remainder can now be performed on constant
  1153 arguments;
  1154 
  1155 * many properties of integer multiplication, division and remainder
  1156 are now available;
  1157 
  1158 * An interface to the Stanford Validity Checker (SVC) is available through the
  1159 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  1160 are proved automatically.  SVC must be installed separately, and its results
  1161 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  1162 invocation of the underlying oracle).  For SVC see
  1163   http://verify.stanford.edu/SVC
  1164 
  1165 * IsaMakefile: the HOL-Real target now builds an actual image;
  1166 
  1167 
  1168 ** HOL misc **
  1169 
  1170 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  1171 (in Isabelle/Isar) -- by Gertrud Bauer;
  1172 
  1173 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  1174 analysis for assembly languages with subtypes;
  1175 
  1176 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  1177 -- avoids syntactic ambiguities and treats state, transition, and
  1178 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  1179 changed syntax and (many) tactics;
  1180 
  1181 * HOL/inductive: Now also handles more general introduction rules such
  1182   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  1183   theorems are now maintained within the theory (maintained via the
  1184   "mono" attribute);
  1185 
  1186 * HOL/datatype: Now also handles arbitrarily branching datatypes
  1187   (using function types) such as
  1188 
  1189   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  1190 
  1191 * HOL/record: record_simproc (part of the default simpset) takes care
  1192 of selectors applied to updated records; record_split_tac is no longer
  1193 part of the default claset; update_defs may now be removed from the
  1194 simpset in many cases; COMPATIBILITY: old behavior achieved by
  1195 
  1196   claset_ref () := claset() addSWrapper record_split_wrapper;
  1197   Delsimprocs [record_simproc]
  1198 
  1199 * HOL/typedef: fixed type inference for representing set; type
  1200 arguments now have to occur explicitly on the rhs as type constraints;
  1201 
  1202 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  1203 names rather than an ML expression;
  1204 
  1205 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  1206 supplied later.  Program schemes can be defined, such as
  1207     "While B C s = (if B s then While B C (C s) else s)"
  1208 where the well-founded relation can be chosen after B and C have been given.
  1209 
  1210 * HOL/List: the constructors of type list are now Nil and Cons;
  1211 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  1212 course, ML tools referring to List.list.op # etc. have to be adapted;
  1213 
  1214 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  1215 disabled by default; run isabelle with option -m HOL to get back to
  1216 the original Gordon/HOL-style output;
  1217 
  1218 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  1219 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  1220 
  1221 * HOL basic syntax simplified (more orthogonal): all variants of
  1222 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  1223 Eps operator is provided as well: "SOME x. P[x]";
  1224 
  1225 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  1226 
  1227 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  1228 thus available for user theories;
  1229 
  1230 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  1231 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  1232 time;
  1233 
  1234 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  1235 several times and then mp;
  1236 
  1237 
  1238 *** LK ***
  1239 
  1240 * the notation <<...>> is now available as a notation for sequences of
  1241 formulas;
  1242 
  1243 * the simplifier is now installed
  1244 
  1245 * the axiom system has been generalized (thanks to Soren Heilmann)
  1246 
  1247 * the classical reasoner now has a default rule database
  1248 
  1249 
  1250 *** ZF ***
  1251 
  1252 * new primrec section allows primitive recursive functions to be given
  1253 directly (as in HOL) over datatypes and the natural numbers;
  1254 
  1255 * new tactics induct_tac and exhaust_tac for induction (or case
  1256 analysis) over datatypes and the natural numbers;
  1257 
  1258 * the datatype declaration of type T now defines the recursor T_rec;
  1259 
  1260 * simplification automatically does freeness reasoning for datatype
  1261 constructors;
  1262 
  1263 * automatic type-inference, with AddTCs command to insert new
  1264 type-checking rules;
  1265 
  1266 * datatype introduction rules are now added as Safe Introduction rules
  1267 to the claset;
  1268 
  1269 * the syntax "if P then x else y" is now available in addition to
  1270 if(P,x,y);
  1271 
  1272 
  1273 *** Internal programming interfaces ***
  1274 
  1275 * tuned simplifier trace output; new flag debug_simp;
  1276 
  1277 * structures Vartab / Termtab (instances of TableFun) offer efficient
  1278 tables indexed by indexname_ord / term_ord (compatible with aconv);
  1279 
  1280 * AxClass.axclass_tac lost the theory argument;
  1281 
  1282 * tuned current_goals_markers semantics: begin / end goal avoids
  1283 printing empty lines;
  1284 
  1285 * removed prs and prs_fn hook, which was broken because it did not
  1286 include \n in its semantics, forcing writeln to add one
  1287 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  1288 string -> unit if you really want to output text without newline;
  1289 
  1290 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  1291 plain output, interface builders may have to enable 'isabelle_font'
  1292 mode to get Isabelle font glyphs as before;
  1293 
  1294 * refined token_translation interface; INCOMPATIBILITY: output length
  1295 now of type real instead of int;
  1296 
  1297 * theory loader actions may be traced via new ThyInfo.add_hook
  1298 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  1299 your own database of information attached to *whole* theories -- as
  1300 opposed to intra-theory data slots offered via TheoryDataFun;
  1301 
  1302 * proper handling of dangling sort hypotheses (at last!);
  1303 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  1304 extra sort hypotheses that can be witnessed from the type signature;
  1305 the force_strip_shyps flag is gone, any remaining shyps are simply
  1306 left in the theorem (with a warning issued by strip_shyps_warning);
  1307 
  1308 
  1309 
  1310 New in Isabelle98-1 (October 1998)
  1311 ----------------------------------
  1312 
  1313 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1314 
  1315 * several changes of automated proof tools;
  1316 
  1317 * HOL: major changes to the inductive and datatype packages, including
  1318 some minor incompatibilities of theory syntax;
  1319 
  1320 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  1321 called `inj_on';
  1322 
  1323 * HOL: removed duplicate thms in Arith:
  1324   less_imp_add_less  should be replaced by  trans_less_add1
  1325   le_imp_add_le      should be replaced by  trans_le_add1
  1326 
  1327 * HOL: unary minus is now overloaded (new type constraints may be
  1328 required);
  1329 
  1330 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  1331 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  1332 now taken as an integer constant.
  1333 
  1334 * Pure: ML function 'theory_of' renamed to 'theory';
  1335 
  1336 
  1337 *** Proof tools ***
  1338 
  1339 * Simplifier:
  1340   1. Asm_full_simp_tac is now more aggressive.
  1341      1. It will sometimes reorient premises if that increases their power to
  1342         simplify.
  1343      2. It does no longer proceed strictly from left to right but may also
  1344         rotate premises to achieve further simplification.
  1345      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  1346      old Asm_full_simp_tac in that it does not rotate premises.
  1347   2. The simplifier now knows a little bit about nat-arithmetic.
  1348 
  1349 * Classical reasoner: wrapper mechanism for the classical reasoner now
  1350 allows for selected deletion of wrappers, by introduction of names for
  1351 wrapper functionals.  This implies that addbefore, addSbefore,
  1352 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  1353 and that adding two tactics with the same name overwrites the first
  1354 one (emitting a warning).
  1355   type wrapper = (int -> tactic) -> (int -> tactic)
  1356   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  1357   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  1358   delWrapper, delSWrapper: claset *  string            -> claset
  1359   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  1360 
  1361 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  1362 semantics; addbefore now affects only the unsafe part of step_tac
  1363 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  1364 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  1365 by Force_tac;
  1366 
  1367 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  1368 compWrapper; added safe wrapper (and access functions for it);
  1369 
  1370 * HOL/split_all_tac is now much faster and fails if there is nothing
  1371 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  1372 and the names of the automatically generated variables have changed.
  1373 split_all_tac has moved within claset() from unsafe wrappers to safe
  1374 wrappers, which means that !!-bound variables are split much more
  1375 aggressively, and safe_tac and clarify_tac now split such variables.
  1376 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  1377 Note: the same holds for record_split_tac, which does the job of
  1378 split_all_tac for record fields.
  1379 
  1380 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  1381 permanently to the default simpset using Addsplits just like
  1382 Addsimps. They can be removed via Delsplits just like
  1383 Delsimps. Lower-case versions are also available.
  1384 
  1385 * HOL/Simplifier: The rule split_if is now part of the default
  1386 simpset. This means that the simplifier will eliminate all occurrences
  1387 of if-then-else in the conclusion of a goal. To prevent this, you can
  1388 either remove split_if completely from the default simpset by
  1389 `Delsplits [split_if]' or remove it in a specific call of the
  1390 simplifier using `... delsplits [split_if]'.  You can also add/delete
  1391 other case splitting rules to/from the default simpset: every datatype
  1392 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  1393 t is the name of the datatype).
  1394 
  1395 * Classical reasoner / Simplifier combination: new force_tac (and
  1396 derivatives Force_tac, force) combines rewriting and classical
  1397 reasoning (and whatever other tools) similarly to auto_tac, but is
  1398 aimed to solve the given subgoal completely.
  1399 
  1400 
  1401 *** General ***
  1402 
  1403 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  1404 and `goalw': the theory is no longer needed as an explicit argument -
  1405 the current theory context is used; assumptions are no longer returned
  1406 at the ML-level unless one of them starts with ==> or !!; it is
  1407 recommended to convert to these new commands using isatool fixgoal
  1408 (backup your sources first!);
  1409 
  1410 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  1411 the current theory context, and 'theory' to lookup stored theories;
  1412 
  1413 * new theory section 'locale' for declaring constants, assumptions and
  1414 definitions that have local scope;
  1415 
  1416 * new theory section 'nonterminals' for purely syntactic types;
  1417 
  1418 * new theory section 'setup' for generic ML setup functions
  1419 (e.g. package initialization);
  1420 
  1421 * the distribution now includes Isabelle icons: see
  1422 lib/logo/isabelle-{small,tiny}.xpm;
  1423 
  1424 * isatool install - install binaries with absolute references to
  1425 ISABELLE_HOME/bin;
  1426 
  1427 * isatool logo -- create instances of the Isabelle logo (as EPS);
  1428 
  1429 * print mode 'emacs' reserved for Isamode;
  1430 
  1431 * support multiple print (ast) translations per constant name;
  1432 
  1433 * theorems involving oracles are now printed with a suffixed [!];
  1434 
  1435 
  1436 *** HOL ***
  1437 
  1438 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  1439 
  1440 * HOL/inductive package reorganized and improved: now supports mutual
  1441 definitions such as
  1442 
  1443   inductive EVEN ODD
  1444     intrs
  1445       null "0 : EVEN"
  1446       oddI "n : EVEN ==> Suc n : ODD"
  1447       evenI "n : ODD ==> Suc n : EVEN"
  1448 
  1449 new theorem list "elims" contains an elimination rule for each of the
  1450 recursive sets; inductive definitions now handle disjunctive premises
  1451 correctly (also ZF);
  1452 
  1453 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  1454 "mutual_induct" no longer exists - the induction rule is always
  1455 contained in "induct";
  1456 
  1457 
  1458 * HOL/datatype package re-implemented and greatly improved: now
  1459 supports mutually recursive datatypes such as
  1460 
  1461   datatype
  1462     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  1463             | SUM ('a aexp) ('a aexp)
  1464             | DIFF ('a aexp) ('a aexp)
  1465             | NUM 'a
  1466   and
  1467     'a bexp = LESS ('a aexp) ('a aexp)
  1468             | AND ('a bexp) ('a bexp)
  1469             | OR ('a bexp) ('a bexp)
  1470 
  1471 as well as indirectly recursive datatypes such as
  1472 
  1473   datatype
  1474     ('a, 'b) term = Var 'a
  1475                   | App 'b ((('a, 'b) term) list)
  1476 
  1477 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  1478 induction on mutually / indirectly recursive datatypes.
  1479 
  1480 Primrec equations are now stored in theory and can be accessed via
  1481 <function_name>.simps.
  1482 
  1483 INCOMPATIBILITIES:
  1484 
  1485   - Theories using datatypes must now have theory Datatype as an
  1486     ancestor.
  1487   - The specific <typename>.induct_tac no longer exists - use the
  1488     generic induct_tac instead.
  1489   - natE has been renamed to nat.exhaust - use exhaust_tac
  1490     instead of res_inst_tac ... natE. Note that the variable
  1491     names in nat.exhaust differ from the names in natE, this
  1492     may cause some "fragile" proofs to fail.
  1493   - The theorems split_<typename>_case and split_<typename>_case_asm
  1494     have been renamed to <typename>.split and <typename>.split_asm.
  1495   - Since default sorts of type variables are now handled correctly,
  1496     some datatype definitions may have to be annotated with explicit
  1497     sort constraints.
  1498   - Primrec definitions no longer require function name and type
  1499     of recursive argument.
  1500 
  1501 Consider using isatool fixdatatype to adapt your theories and proof
  1502 scripts to the new package (backup your sources first!).
  1503 
  1504 
  1505 * HOL/record package: considerably improved implementation; now
  1506 includes concrete syntax for record types, terms, updates; theorems
  1507 for surjective pairing and splitting !!-bound record variables; proof
  1508 support is as follows:
  1509 
  1510   1) standard conversions (selectors or updates applied to record
  1511 constructor terms) are part of the standard simpset;
  1512 
  1513   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  1514 made part of standard simpset and claset via addIffs;
  1515 
  1516   3) a tactic for record field splitting (record_split_tac) is part of
  1517 the standard claset (addSWrapper);
  1518 
  1519 To get a better idea about these rules you may retrieve them via
  1520 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  1521 the name of your record type.
  1522 
  1523 The split tactic 3) conceptually simplifies by the following rule:
  1524 
  1525   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  1526 
  1527 Thus any record variable that is bound by meta-all will automatically
  1528 blow up into some record constructor term, consequently the
  1529 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  1530 solve record problems automatically.
  1531 
  1532 
  1533 * reorganized the main HOL image: HOL/Integ and String loaded by
  1534 default; theory Main includes everything;
  1535 
  1536 * automatic simplification of integer sums and comparisons, using cancellation;
  1537 
  1538 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  1539 
  1540 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  1541 
  1542 * many new identities for unions, intersections, set difference, etc.;
  1543 
  1544 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  1545 called split_if, split_split, split_sum_case and split_nat_case (to go
  1546 with add/delsplits);
  1547 
  1548 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  1549 (?x::unit) = (); this is made part of the default simpset, which COULD
  1550 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  1551 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  1552 unit_abs_eta_conv is added in order to counter the effect of
  1553 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  1554 %u.f();
  1555 
  1556 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  1557 makes more sense);
  1558 
  1559 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1560   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1561   disjointness reasoning but breaking a few old proofs.
  1562 
  1563 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  1564 to 'converse' from 'inverse' (for compatibility with ZF and some
  1565 literature);
  1566 
  1567 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  1568 the well-founded relation;
  1569 
  1570 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  1571     Compl A.  The "Compl" syntax remains available as input syntax for this
  1572     release ONLY.
  1573 
  1574 * HOL/Update: new theory of function updates:
  1575     f(a:=b) == %x. if x=a then b else f x
  1576 may also be iterated as in f(a:=b,c:=d,...);
  1577 
  1578 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  1579 
  1580 * HOL/List:
  1581   - new function list_update written xs[i:=v] that updates the i-th
  1582     list position. May also be iterated as in xs[i:=a,j:=b,...].
  1583   - new function `upt' written [i..j(] which generates the list
  1584     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  1585     bound write [i..j], which is a shorthand for [i..j+1(].
  1586   - new lexicographic orderings and corresponding wellfoundedness theorems.
  1587 
  1588 * HOL/Arith:
  1589   - removed 'pred' (predecessor) function;
  1590   - generalized some theorems about n-1;
  1591   - many new laws about "div" and "mod";
  1592   - new laws about greatest common divisors (see theory ex/Primes);
  1593 
  1594 * HOL/Relation: renamed the relational operator r^-1 "converse"
  1595 instead of "inverse";
  1596 
  1597 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  1598   of the multiset ordering;
  1599 
  1600 * directory HOL/Real: a construction of the reals using Dedekind cuts
  1601   (not included by default);
  1602 
  1603 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  1604 
  1605 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  1606   programs, i.e. different program variables may have different types.
  1607 
  1608 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1609   [previously, this check worked only if the rewrite rule was unconditional]
  1610   Now rew can involve either definitions or equalities (either == or =).
  1611 
  1612 
  1613 *** ZF ***
  1614 
  1615 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  1616   only the theorems proved on ZF.ML;
  1617 
  1618 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1619   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1620   disjointness reasoning but breaking a few old proofs.
  1621 
  1622 * ZF/Update: new theory of function updates
  1623     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  1624   may also be iterated as in f(a:=b,c:=d,...);
  1625 
  1626 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  1627 
  1628 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1629   [previously, this check worked only if the rewrite rule was unconditional]
  1630   Now rew can involve either definitions or equalities (either == or =).
  1631 
  1632 * case_tac provided for compatibility with HOL
  1633     (like the old excluded_middle_tac, but with subgoals swapped)
  1634 
  1635 
  1636 *** Internal programming interfaces ***
  1637 
  1638 * Pure: several new basic modules made available for general use, see
  1639 also src/Pure/README;
  1640 
  1641 * improved the theory data mechanism to support encapsulation (data
  1642 kind name replaced by private Object.kind, acting as authorization
  1643 key); new type-safe user interface via functor TheoryDataFun; generic
  1644 print_data function becomes basically useless;
  1645 
  1646 * removed global_names compatibility flag -- all theory declarations
  1647 are qualified by default;
  1648 
  1649 * module Pure/Syntax now offers quote / antiquote translation
  1650 functions (useful for Hoare logic etc. with implicit dependencies);
  1651 see HOL/ex/Antiquote for an example use;
  1652 
  1653 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  1654 cterm -> thm;
  1655 
  1656 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  1657 subgoal;
  1658 
  1659 * Display.print_goals function moved to Locale.print_goals;
  1660 
  1661 * standard print function for goals supports current_goals_markers
  1662 variable for marking begin of proof, end of proof, start of goal; the
  1663 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  1664 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  1665 for example;
  1666 
  1667 
  1668 
  1669 New in Isabelle98 (January 1998)
  1670 --------------------------------
  1671 
  1672 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1673 
  1674 * changed lexical syntax of terms / types: dots made part of long
  1675 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  1676 
  1677 * simpset (and claset) reference variable replaced by functions
  1678 simpset / simpset_ref;
  1679 
  1680 * no longer supports theory aliases (via merge) and non-trivial
  1681 implicit merge of thms' signatures;
  1682 
  1683 * most internal names of constants changed due to qualified names;
  1684 
  1685 * changed Pure/Sequence interface (see Pure/seq.ML);
  1686 
  1687 
  1688 *** General Changes ***
  1689 
  1690 * hierachically structured name spaces (for consts, types, axms, thms
  1691 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  1692 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  1693 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  1694 long_names for fully qualified output names; NOTE: ML programs
  1695 (special tactics, packages etc.) referring to internal names may have
  1696 to be adapted to cope with fully qualified names; in case of severe
  1697 backward campatibility problems try setting 'global_names' at compile
  1698 time to have enrything declared within a flat name space; one may also
  1699 fine tune name declarations in theories via the 'global' and 'local'
  1700 section;
  1701 
  1702 * reimplemented the implicit simpset and claset using the new anytype
  1703 data filed in signatures; references simpset:simpset ref etc. are
  1704 replaced by functions simpset:unit->simpset and
  1705 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  1706 to patch your ML files accordingly;
  1707 
  1708 * HTML output now includes theory graph data for display with Java
  1709 applet or isatool browser; data generated automatically via isatool
  1710 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  1711 
  1712 * defs may now be conditional; improved rewrite_goals_tac to handle
  1713 conditional equations;
  1714 
  1715 * defs now admits additional type arguments, using TYPE('a) syntax;
  1716 
  1717 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  1718 creates a new theory node; implicit merge of thms' signatures is
  1719 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  1720 transfer:theory->thm->thm in (rare) cases;
  1721 
  1722 * improved handling of draft signatures / theories; draft thms (and
  1723 ctyps, cterms) are automatically promoted to real ones;
  1724 
  1725 * slightly changed interfaces for oracles: admit many per theory, named
  1726 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  1727 
  1728 * print_goals: optional output of const types (set show_consts and
  1729 show_types);
  1730 
  1731 * improved output of warnings (###) and errors (***);
  1732 
  1733 * subgoal_tac displays a warning if the new subgoal has type variables;
  1734 
  1735 * removed old README and Makefiles;
  1736 
  1737 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  1738 
  1739 * removed obsolete init_pps and init_database;
  1740 
  1741 * deleted the obsolete tactical STATE, which was declared by
  1742     fun STATE tacfun st = tacfun st st;
  1743 
  1744 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  1745 (which abbreviates $HOME);
  1746 
  1747 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  1748 use isatool fixseq to adapt your ML programs (this works for fully
  1749 qualified references to the Sequence structure only!);
  1750 
  1751 * use_thy no longer requires writable current directory; it always
  1752 reloads .ML *and* .thy file, if either one is out of date;
  1753 
  1754 
  1755 *** Classical Reasoner ***
  1756 
  1757 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  1758 tactics that use classical reasoning to simplify a subgoal without
  1759 splitting it into several subgoals;
  1760 
  1761 * Safe_tac: like safe_tac but uses the default claset;
  1762 
  1763 
  1764 *** Simplifier ***
  1765 
  1766 * added simplification meta rules:
  1767     (asm_)(full_)simplify: simpset -> thm -> thm;
  1768 
  1769 * simplifier.ML no longer part of Pure -- has to be loaded by object
  1770 logics (again);
  1771 
  1772 * added prems argument to simplification procedures;
  1773 
  1774 * HOL, FOL, ZF: added infix function `addsplits':
  1775   instead of `<simpset> setloop (split_tac <thms>)'
  1776   you can simply write `<simpset> addsplits <thms>'
  1777 
  1778 
  1779 *** Syntax ***
  1780 
  1781 * TYPE('a) syntax for type reflection terms;
  1782 
  1783 * no longer handles consts with name "" -- declare as 'syntax' instead;
  1784 
  1785 * pretty printer: changed order of mixfix annotation preference (again!);
  1786 
  1787 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  1788 
  1789 
  1790 *** HOL ***
  1791 
  1792 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1793   with `addloop' of the simplifier to faciliate case splitting in premises.
  1794 
  1795 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  1796 
  1797 * HOL/Auth: new protocol proofs including some for the Internet
  1798   protocol TLS;
  1799 
  1800 * HOL/Map: new theory of `maps' a la VDM;
  1801 
  1802 * HOL/simplifier: simplification procedures nat_cancel_sums for
  1803 cancelling out common nat summands from =, <, <= (in)equalities, or
  1804 differences; simplification procedures nat_cancel_factor for
  1805 cancelling common factor from =, <, <= (in)equalities over natural
  1806 sums; nat_cancel contains both kinds of procedures, it is installed by
  1807 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  1808 
  1809 * HOL/simplifier: terms of the form
  1810   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  1811   are rewritten to
  1812   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  1813   and those of the form
  1814   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  1815   are rewritten to
  1816   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  1817 
  1818 * HOL/datatype
  1819   Each datatype `t' now comes with a theorem `split_t_case' of the form
  1820 
  1821   P(t_case f1 ... fn x) =
  1822      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  1823         ...
  1824        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  1825      )
  1826 
  1827   and a theorem `split_t_case_asm' of the form
  1828 
  1829   P(t_case f1 ... fn x) =
  1830     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  1831         ...
  1832        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  1833      )
  1834   which can be added to a simpset via `addsplits'. The existing theorems
  1835   expand_list_case and expand_option_case have been renamed to
  1836   split_list_case and split_option_case.
  1837 
  1838 * HOL/Arithmetic:
  1839   - `pred n' is automatically converted to `n-1'.
  1840     Users are strongly encouraged not to use `pred' any longer,
  1841     because it will disappear altogether at some point.
  1842   - Users are strongly encouraged to write "0 < n" rather than
  1843     "n ~= 0". Theorems and proof tools have been modified towards this
  1844     `standard'.
  1845 
  1846 * HOL/Lists:
  1847   the function "set_of_list" has been renamed "set" (and its theorems too);
  1848   the function "nth" now takes its arguments in the reverse order and
  1849   has acquired the infix notation "!" as in "xs!n".
  1850 
  1851 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  1852 
  1853 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  1854   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  1855 
  1856 * HOL/record: extensible records with schematic structural subtyping
  1857 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  1858 still lacks various theorems and concrete record syntax;
  1859 
  1860 
  1861 *** HOLCF ***
  1862 
  1863 * removed "axioms" and "generated by" sections;
  1864 
  1865 * replaced "ops" section by extended "consts" section, which is capable of
  1866   handling the continuous function space "->" directly;
  1867 
  1868 * domain package:
  1869   . proves theorems immediately and stores them in the theory,
  1870   . creates hierachical name space,
  1871   . now uses normal mixfix annotations (instead of cinfix...),
  1872   . minor changes to some names and values (for consistency),
  1873   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  1874   . separator between mutual domain defs: changed "," to "and",
  1875   . improved handling of sort constraints;  now they have to
  1876     appear on the left-hand side of the equations only;
  1877 
  1878 * fixed LAM <x,y,zs>.b syntax;
  1879 
  1880 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  1881 adm (%x. P (t x)), where P is chainfinite and t continuous;
  1882 
  1883 
  1884 *** FOL and ZF ***
  1885 
  1886 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1887   with `addloop' of the simplifier to faciliate case splitting in premises.
  1888 
  1889 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  1890 in HOL, they strip ALL and --> from proved theorems;
  1891 
  1892 
  1893 
  1894 New in Isabelle94-8 (May 1997)
  1895 ------------------------------
  1896 
  1897 *** General Changes ***
  1898 
  1899 * new utilities to build / run / maintain Isabelle etc. (in parts
  1900 still somewhat experimental); old Makefiles etc. still functional;
  1901 
  1902 * new 'Isabelle System Manual';
  1903 
  1904 * INSTALL text, together with ./configure and ./build scripts;
  1905 
  1906 * reimplemented type inference for greater efficiency, better error
  1907 messages and clean internal interface;
  1908 
  1909 * prlim command for dealing with lots of subgoals (an easier way of
  1910 setting goals_limit);
  1911 
  1912 
  1913 *** Syntax ***
  1914 
  1915 * supports alternative (named) syntax tables (parser and pretty
  1916 printer); internal interface is provided by add_modesyntax(_i);
  1917 
  1918 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  1919 be used in conjunction with the Isabelle symbol font; uses the
  1920 "symbols" syntax table;
  1921 
  1922 * added token_translation interface (may translate name tokens in
  1923 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  1924 the current print_mode); IMPORTANT: user print translation functions
  1925 are responsible for marking newly introduced bounds
  1926 (Syntax.mark_boundT);
  1927 
  1928 * token translations for modes "xterm" and "xterm_color" that display
  1929 names in bold, underline etc. or colors (which requires a color
  1930 version of xterm);
  1931 
  1932 * infixes may now be declared with names independent of their syntax;
  1933 
  1934 * added typed_print_translation (like print_translation, but may
  1935 access type of constant);
  1936 
  1937 
  1938 *** Classical Reasoner ***
  1939 
  1940 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  1941 some limitations.  Blast_tac...
  1942   + ignores addss, addbefore, addafter; this restriction is intrinsic
  1943   + ignores elimination rules that don't have the correct format
  1944         (the conclusion MUST be a formula variable)
  1945   + ignores types, which can make HOL proofs fail
  1946   + rules must not require higher-order unification, e.g. apply_type in ZF
  1947     [message "Function Var's argument not a bound variable" relates to this]
  1948   + its proof strategy is more general but can actually be slower
  1949 
  1950 * substitution with equality assumptions no longer permutes other
  1951 assumptions;
  1952 
  1953 * minor changes in semantics of addafter (now called addaltern); renamed
  1954 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  1955 (and access functions for it);
  1956 
  1957 * improved combination of classical reasoner and simplifier:
  1958   + functions for handling clasimpsets
  1959   + improvement of addss: now the simplifier is called _after_ the
  1960     safe steps.
  1961   + safe variant of addss called addSss: uses safe simplifications
  1962     _during_ the safe steps. It is more complete as it allows multiple
  1963     instantiations of unknowns (e.g. with slow_tac).
  1964 
  1965 *** Simplifier ***
  1966 
  1967 * added interface for simplification procedures (functions that
  1968 produce *proven* rewrite rules on the fly, depending on current
  1969 redex);
  1970 
  1971 * ordering on terms as parameter (used for ordered rewriting);
  1972 
  1973 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  1974 
  1975 * the solver is now split into a safe and an unsafe part.
  1976 This should be invisible for the normal user, except that the
  1977 functions setsolver and addsolver have been renamed to setSolver and
  1978 addSolver; added safe_asm_full_simp_tac;
  1979 
  1980 
  1981 *** HOL ***
  1982 
  1983 * a generic induction tactic `induct_tac' which works for all datatypes and
  1984 also for type `nat';
  1985 
  1986 * a generic case distinction tactic `exhaust_tac' which works for all
  1987 datatypes and also for type `nat';
  1988 
  1989 * each datatype comes with a function `size';
  1990 
  1991 * patterns in case expressions allow tuple patterns as arguments to
  1992 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  1993 
  1994 * primrec now also works with type nat;
  1995 
  1996 * recdef: a new declaration form, allows general recursive functions to be
  1997 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  1998 
  1999 * the constant for negation has been renamed from "not" to "Not" to
  2000 harmonize with FOL, ZF, LK, etc.;
  2001 
  2002 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  2003 infinite lists;
  2004 
  2005 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  2006 
  2007 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  2008 problems in commutative rings, using axiomatic type classes for + and *;
  2009 
  2010 * more examples in HOL/MiniML and HOL/Auth;
  2011 
  2012 * more default rewrite rules for quantifiers, union/intersection;
  2013 
  2014 * a new constant `arbitrary == @x.False';
  2015 
  2016 * HOLCF/IOA replaces old HOL/IOA;
  2017 
  2018 * HOLCF changes: derived all rules and arities
  2019   + axiomatic type classes instead of classes
  2020   + typedef instead of faking type definitions
  2021   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  2022   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  2023   + eliminated the types void, one, tr
  2024   + use unit lift and bool lift (with translations) instead of one and tr
  2025   + eliminated blift from Lift3.thy (use Def instead of blift)
  2026   all eliminated rules are derived as theorems --> no visible changes ;
  2027 
  2028 
  2029 *** ZF ***
  2030 
  2031 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  2032 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  2033 as ZF_cs addSIs [equalityI];
  2034 
  2035 
  2036 
  2037 New in Isabelle94-7 (November 96)
  2038 ---------------------------------
  2039 
  2040 * allowing negative levels (as offsets) in prlev and choplev;
  2041 
  2042 * super-linear speedup for large simplifications;
  2043 
  2044 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  2045 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  2046 FAIL); can suppress it using the command Delsimps (ex_simps @
  2047 all_simps); De Morgan laws are also now included, by default;
  2048 
  2049 * improved printing of ==>  :  ~:
  2050 
  2051 * new object-logic "Sequents" adds linear logic, while replacing LK
  2052 and Modal (thanks to Sara Kalvala);
  2053 
  2054 * HOL/Auth: correctness proofs for authentication protocols;
  2055 
  2056 * HOL: new auto_tac combines rewriting and classical reasoning (many
  2057 examples on HOL/Auth);
  2058 
  2059 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  2060 the rewriter and classical reasoner simultaneously;
  2061 
  2062 * function uresult no longer returns theorems in "standard" format;
  2063 regain previous version by: val uresult = standard o uresult;
  2064 
  2065 
  2066 
  2067 New in Isabelle94-6
  2068 -------------------
  2069 
  2070 * oracles -- these establish an interface between Isabelle and trusted
  2071 external reasoners, which may deliver results as theorems;
  2072 
  2073 * proof objects (in particular record all uses of oracles);
  2074 
  2075 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  2076 
  2077 * "constdefs" section in theory files;
  2078 
  2079 * "primrec" section (HOL) no longer requires names;
  2080 
  2081 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  2082 
  2083 
  2084 
  2085 New in Isabelle94-5
  2086 -------------------
  2087 
  2088 * reduced space requirements;
  2089 
  2090 * automatic HTML generation from theories;
  2091 
  2092 * theory files no longer require "..." (quotes) around most types;
  2093 
  2094 * new examples, including two proofs of the Church-Rosser theorem;
  2095 
  2096 * non-curried (1994) version of HOL is no longer distributed;
  2097 
  2098 
  2099 
  2100 New in Isabelle94-4
  2101 -------------------
  2102 
  2103 * greatly reduced space requirements;
  2104 
  2105 * theory files (.thy) no longer require \...\ escapes at line breaks;
  2106 
  2107 * searchable theorem database (see the section "Retrieving theorems" on
  2108 page 8 of the Reference Manual);
  2109 
  2110 * new examples, including Grabczewski's monumental case study of the
  2111 Axiom of Choice;
  2112 
  2113 * The previous version of HOL renamed to Old_HOL;
  2114 
  2115 * The new version of HOL (previously called CHOL) uses a curried syntax
  2116 for functions.  Application looks like f a b instead of f(a,b);
  2117 
  2118 * Mutually recursive inductive definitions finally work in HOL;
  2119 
  2120 * In ZF, pattern-matching on tuples is now available in all abstractions and
  2121 translates to the operator "split";
  2122 
  2123 
  2124 
  2125 New in Isabelle94-3
  2126 -------------------
  2127 
  2128 * new infix operator, addss, allowing the classical reasoner to
  2129 perform simplification at each step of its search.  Example:
  2130         fast_tac (cs addss ss)
  2131 
  2132 * a new logic, CHOL, the same as HOL, but with a curried syntax
  2133 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  2134 look like (a,b) instead of <a,b>;
  2135 
  2136 * PLEASE NOTE: CHOL will eventually replace HOL!
  2137 
  2138 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  2139 It translates to the operator "split".  A new theory of integers is available;
  2140 
  2141 * In ZF, integer numerals now denote two's-complement binary integers.
  2142 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  2143 
  2144 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  2145 of the Axiom of Choice;
  2146 
  2147 
  2148 
  2149 New in Isabelle94-2
  2150 -------------------
  2151 
  2152 * Significantly faster resolution;
  2153 
  2154 * the different sections in a .thy file can now be mixed and repeated
  2155 freely;
  2156 
  2157 * Database of theorems for FOL, HOL and ZF.  New
  2158 commands including qed, qed_goal and bind_thm store theorems in the database.
  2159 
  2160 * Simple database queries: return a named theorem (get_thm) or all theorems of
  2161 a given theory (thms_of), or find out what theory a theorem was proved in
  2162 (theory_of_thm);
  2163 
  2164 * Bugs fixed in the inductive definition and datatype packages;
  2165 
  2166 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  2167 and HOL_dup_cs obsolete;
  2168 
  2169 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  2170 have been removed;
  2171 
  2172 * Simpler definition of function space in ZF;
  2173 
  2174 * new results about cardinal and ordinal arithmetic in ZF;
  2175 
  2176 * 'subtype' facility in HOL for introducing new types as subsets of existing
  2177 types;
  2178 
  2179 
  2180 $Id$