NEWS
author wenzelm
Thu Feb 21 20:06:39 2002 +0100 (2002-02-21)
changeset 12917 0fd3caa5d8b2
parent 12899 7d5b690253ee
child 12924 02eb40cde931
permissions -rw-r--r--
* HOL: removed obsolete theorem "optionE";
     1 
     2 Isabelle NEWS -- history user-relevant changes
     3 ==============================================
     4 
     5 New in Isabelle2002 (January 2002)
     6 ----------------------------------
     7 
     8 *** Document preparation ***
     9 
    10 * greatly simplified document preparation setup, including more
    11 graceful interpretation of isatool usedir -i/-d/-D options, and more
    12 instructive isatool mkdir; users should basically be able to get
    13 started with "isatool mkdir HOL Test && isatool make"; alternatively,
    14 users may run a separate document processing stage manually like this:
    15 "isatool usedir -D output HOL Test && isatool document Test/output";
    16 
    17 * theory dependency graph may now be incorporated into documents;
    18 isatool usedir -g true will produce session_graph.eps/.pdf for use
    19 with \includegraphics of LaTeX;
    20 
    21 * proper spacing of consecutive markup elements, especially text
    22 blocks after section headings;
    23 
    24 * support bold style (for single symbols only), input syntax is like
    25 this: "\<^bold>\<alpha>" or "\<^bold>A";
    26 
    27 * \<bullet> is now output as bold \cdot by default, which looks much
    28 better in printed text;
    29 
    30 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
    31 note that these symbols are currently unavailable in Proof General /
    32 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
    33 
    34 * isatool latex no longer depends on changed TEXINPUTS, instead
    35 isatool document copies the Isabelle style files to the target
    36 location;
    37 
    38 
    39 *** Isar ***
    40 
    41 * Pure/Provers: improved proof by cases and induction;
    42   - 'case' command admits impromptu naming of parameters (such as
    43     "case (Suc n)");
    44   - 'induct' method divinates rule instantiation from the inductive
    45     claim; no longer requires excessive ?P bindings for proper
    46     instantiation of cases;
    47   - 'induct' method properly enumerates all possibilities of set/type
    48     rules; as a consequence facts may be also passed through *type*
    49     rules without further ado;
    50   - 'induct' method now derives symbolic cases from the *rulified*
    51     rule (before it used to rulify cases stemming from the internal
    52     atomized version); this means that the context of a non-atomic
    53     statement becomes is included in the hypothesis, avoiding the
    54     slightly cumbersome show "PROP ?case" form;
    55   - 'induct' may now use elim-style induction rules without chaining
    56     facts, using ``missing'' premises from the goal state; this allows
    57     rules stemming from inductive sets to be applied in unstructured
    58     scripts, while still benefitting from proper handling of non-atomic
    59     statements; NB: major inductive premises need to be put first, all
    60     the rest of the goal is passed through the induction;
    61   - 'induct' proper support for mutual induction involving non-atomic
    62     rule statements (uses the new concept of simultaneous goals, see
    63     below);
    64   - append all possible rule selections, but only use the first
    65     success (no backtracking);
    66   - removed obsolete "(simplified)" and "(stripped)" options of methods;
    67   - undeclared rule case names default to numbers 1, 2, 3, ...;
    68   - added 'print_induct_rules' (covered by help item in recent Proof
    69     General versions);
    70   - moved induct/cases attributes to Pure, methods to Provers;
    71   - generic method setup instantiated for FOL and HOL;
    72 
    73 * Pure: support multiple simultaneous goal statements, for example
    74 "have a: A and b: B" (same for 'theorem' etc.); being a pure
    75 meta-level mechanism, this acts as if several individual goals had
    76 been stated separately; in particular common proof methods need to be
    77 repeated in order to cover all claims; note that a single elimination
    78 step is *not* sufficient to establish the two conjunctions, so this
    79 fails:
    80 
    81   assume "A & B" then have A and B ..   (*".." fails*)
    82 
    83 better use "obtain" in situations as above; alternative refer to
    84 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
    85 
    86 * Pure: proper integration with ``locales''; unlike the original
    87 version by Florian Kammüller, Isar locales package high-level proof
    88 contexts rather than raw logical ones (e.g. we admit to include
    89 attributes everywhere); operations on locales include merge and
    90 rename; e.g. see HOL/ex/Locales.thy;
    91 
    92 * Pure: the following commands have been ``localized'', supporting a
    93 target locale specification "(in name)": 'lemma', 'theorem',
    94 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
    95 stored both within the locale and at the theory level (exported and
    96 qualified by the locale name);
    97 
    98 * Pure: theory goals now support ad-hoc contexts, which are discharged
    99 in the result, as in ``lemma (assumes A and B) K: A .''; syntax
   100 coincides with that of a locale body;
   101 
   102 * Pure: renamed "antecedent" case to "rule_context";
   103 
   104 * Pure: added 'corollary' command;
   105 
   106 * Pure: fixed 'token_translation' command;
   107 
   108 * Pure: removed obsolete 'exported' attribute;
   109 
   110 * Pure: dummy pattern "_" in is/let is now automatically lifted over
   111 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
   112 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
   113 
   114 * Pure: method 'atomize' presents local goal premises as object-level
   115 statements (atomic meta-level propositions); setup controlled via
   116 rewrite rules declarations of 'atomize' attribute; example
   117 application: 'induct' method with proper rule statements in improper
   118 proof *scripts*;
   119 
   120 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
   121 now consider the syntactic context of assumptions, giving a better
   122 chance to get type-inference of the arguments right (this is
   123 especially important for locales);
   124 
   125 * Pure: "sorry" no longer requires quick_and_dirty in interactive
   126 mode;
   127 
   128 * Pure/obtain: the formal conclusion "thesis", being marked as
   129 ``internal'', may no longer be reference directly in the text;
   130 potential INCOMPATIBILITY, may need to use "?thesis" in rare
   131 situations;
   132 
   133 * Pure: generic 'sym' attribute which declares a rule both as pure
   134 'elim?' and for the 'symmetric' operation;
   135 
   136 * Pure: marginal comments ``--'' may now occur just anywhere in the
   137 text; the fixed correlation with particular command syntax has been
   138 discontinued;
   139 
   140 * Pure/Provers/classical: simplified integration with pure rule
   141 attributes and methods; the classical "intro?/elim?/dest?"
   142 declarations coincide with the pure ones; the "rule" method no longer
   143 includes classically swapped intros; "intro" and "elim" methods no
   144 longer pick rules from the context; also got rid of ML declarations
   145 AddXIs/AddXEs/AddXDs; all of this has some potential for
   146 INCOMPATIBILITY;
   147 
   148 * Provers/classical: attribute 'swapped' produces classical inversions
   149 of introduction rules;
   150 
   151 * Provers/simplifier: 'simplified' attribute may refer to explicit
   152 rules instead of full simplifier context; 'iff' attribute handles
   153 conditional rules;
   154 
   155 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
   156 
   157 * HOL: 'recdef' now fails on unfinished automated proofs, use
   158 "(permissive)" option to recover old behavior;
   159 
   160 * HOL: 'inductive' no longer features separate (collective) attributes
   161 for 'intros' (was found too confusing);
   162 
   163 * HOL: properly declared induction rules less_induct and
   164 wf_induct_rule;
   165 
   166 
   167 *** HOL ***
   168 
   169 * HOL: moved over to sane numeral syntax; the new policy is as
   170 follows:
   171 
   172   - 0 and 1 are polymorphic constants, which are defined on any
   173   numeric type (nat, int, real etc.);
   174 
   175   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
   176   binary representation internally;
   177 
   178   - type nat has special constructor Suc, and generally prefers Suc 0
   179   over 1::nat and Suc (Suc 0) over 2::nat;
   180 
   181 This change may cause significant problems of INCOMPATIBILITY; here
   182 are some hints on converting existing sources:
   183 
   184   - due to the new "num" token, "-0" and "-1" etc. are now atomic
   185   entities, so expressions involving "-" (unary or binary minus) need
   186   to be spaced properly;
   187 
   188   - existing occurrences of "1" may need to be constraint "1::nat" or
   189   even replaced by Suc 0; similar for old "2";
   190 
   191   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
   192 
   193   - remove all special provisions on numerals in proofs;
   194 
   195 * HOL: simp rules nat_number_of expand numerals on nat to Suc/0
   196 representation (depends on bin_arith_simps in the default context);
   197 
   198 * HOL: symbolic syntax for x^2 (numeral 2);
   199 
   200 * HOL: the class of all HOL types is now called "type" rather than
   201 "term"; INCOMPATIBILITY, need to adapt references to this type class
   202 in axclass/classes, instance/arities, and (usually rare) occurrences
   203 in typings (of consts etc.); internally the class is called
   204 "HOL.type", ML programs should refer to HOLogic.typeS;
   205 
   206 * HOL/record package improvements:
   207   - new derived operations "fields" to build a partial record section,
   208     "extend" to promote a fixed record to a record scheme, and
   209     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
   210     declared as simp by default;
   211   - shared operations ("more", "fields", etc.) now need to be always
   212     qualified) --- potential INCOMPATIBILITY;
   213   - removed "make_scheme" operations (use "make" with "extend") --
   214     INCOMPATIBILITY;
   215   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
   216   - provides cases/induct rules for use with corresponding Isar
   217     methods (for concrete records, record schemes, concrete more
   218     parts, and schematic more parts -- in that order);
   219   - internal definitions directly based on a light-weight abstract
   220     theory of product types over typedef rather than datatype;
   221 
   222 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
   223 
   224 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
   225 (beware of argument permutation!);
   226 
   227 * HOL: linorder_less_split superseded by linorder_cases;
   228 
   229 * HOL/List: "nodups" renamed to "distinct";
   230 
   231 * HOL: added "The" definite description operator; move Hilbert's "Eps"
   232 to peripheral theory "Hilbert_Choice";
   233 
   234 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
   235 in this (rare) case use:
   236 
   237   delSWrapper "split_all_tac"
   238   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
   239 
   240 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
   241 MAY FAIL;
   242 
   243 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
   244 Isabelle's type classes, ^ on functions and relations has too general
   245 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
   246 necessary to attach explicit type constraints;
   247 
   248 * HOL/Relation: the prefix name of the infix "O" has been changed from
   249 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
   250 renamed accordingly (eg "compI" -> "rel_compI").
   251 
   252 * HOL: syntax translations now work properly with numerals and records
   253 expressions;
   254 
   255 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
   256 of "lam" -- INCOMPATIBILITY;
   257 
   258 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
   259 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
   260 renamed "Product_Type.unit";
   261 
   262 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
   263 
   264 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
   265 Florian Kammüller);
   266 
   267 * HOL/IMP: updated and converted to new-style theory format; several
   268 parts turned into readable document, with proper Isar proof texts and
   269 some explanations (by Gerwin Klein);
   270 
   271 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
   272 
   273 * HOL-Hyperreal is now a logic image;
   274 
   275 
   276 *** HOLCF ***
   277 
   278 * Isar: consts/constdefs supports mixfix syntax for continuous
   279 operations;
   280 
   281 * Isar: domain package adapted to new-style theory format, e.g. see
   282 HOLCF/ex/Dnat.thy;
   283 
   284 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
   285 potential INCOMPATIBILITY; now use plain induct_tac instead of former
   286 lift.induct_tac, always use UU instead of Undef;
   287 
   288 * HOLCF/IMP: updated and converted to new-style theory;
   289 
   290 
   291 *** ZF ***
   292 
   293 * Isar: proper integration of logic-specific tools and packages,
   294 including theory commands '(co)inductive', '(co)datatype',
   295 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
   296 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
   297 
   298 * theory Main no longer includes AC; for the Axiom of Choice, base
   299 your theory on Main_ZFC;
   300 
   301 * the integer library now covers quotients and remainders, with many
   302 laws relating division to addition, multiplication, etc.;
   303 
   304 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
   305 typeless version of the formalism;
   306 
   307 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory format;
   308 
   309 * ZF/Induct: new directory for examples of inductive definitions,
   310 including theory Multiset for multiset orderings; converted to
   311 new-style theory format;
   312 
   313 * Many new theorems about lists, ordinals, etc.;
   314 
   315 
   316 *** General ***
   317 
   318 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
   319 variable proof controls level of detail: 0 = no proofs (only oracle
   320 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
   321 also ref manual for further ML interfaces;
   322 
   323 * Pure/axclass: removed obsolete ML interface
   324 goal_subclass/goal_arity;
   325 
   326 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
   327 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
   328 separate tokens, so expressions involving minus need to be spaced
   329 properly;
   330 
   331 * Pure/syntax: support non-oriented infixes, using keyword "infix"
   332 rather than "infixl" or "infixr";
   333 
   334 * Pure/syntax: concrete syntax for dummy type variables admits genuine
   335 sort constraint specifications in type inference; e.g. "x::_::foo"
   336 ensures that the type of "x" is of sort "foo" (but not necessarily a
   337 type variable);
   338 
   339 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
   340 control output of nested => (types); the default behavior is
   341 "type_brackets";
   342 
   343 * Pure/syntax: builtin parse translation for "_constify" turns valued
   344 tokens into AST constants;
   345 
   346 * Pure/syntax: prefer later declarations of translations and print
   347 translation functions; potential INCOMPATIBILITY: need to reverse
   348 multiple declarations for same syntax element constant;
   349 
   350 * Pure/show_hyps reset by default (in accordance to existing Isar
   351 practice);
   352 
   353 * Provers/classical: renamed addaltern to addafter, addSaltern to
   354 addSafter;
   355 
   356 * Provers/clasimp: ``iff'' declarations now handle conditional rules
   357 as well;
   358 
   359 * system: tested support for MacOS X; should be able to get Isabelle +
   360 Proof General to work in a plain Terminal after installing Poly/ML
   361 (e.g. from the Isabelle distribution area) and GNU bash alone
   362 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
   363 support requires further installations, e.g. from
   364 http://fink.sourceforge.net/);
   365 
   366 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
   367 
   368 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
   369 of 40 MB), cf. ML_OPTIONS;
   370 
   371 * system: Proof General keywords specification is now part of the
   372 Isabelle distribution (see etc/isar-keywords.el);
   373 
   374 * system: support for persistent Proof General sessions (refrain from
   375 outdating all loaded theories on startup); user may create writable
   376 logic images like this: ``isabelle -q HOL Test'';
   377 
   378 * system: smart selection of Isabelle process versus Isabelle
   379 interface, accommodates case-insensitive file systems (e.g. HFS+); may
   380 run both "isabelle" and "Isabelle" even if file names are badly
   381 damaged (executable inspects the case of the first letter of its own
   382 name); added separate "isabelle-process" and "isabelle-interface";
   383 
   384 * system: refrain from any attempt at filtering input streams; no
   385 longer support ``8bit'' encoding of old isabelle font, instead proper
   386 iso-latin characters may now be used; the related isatools
   387 "symbolinput" and "nonascii" have disappeared as well;
   388 
   389 * system: removed old "xterm" interface (the print modes "xterm" and
   390 "xterm_color" are still available for direct use in a suitable
   391 terminal);
   392 
   393 
   394 
   395 New in Isabelle99-2 (February 2001)
   396 -----------------------------------
   397 
   398 *** Overview of INCOMPATIBILITIES ***
   399 
   400 * HOL: please note that theories in the Library and elsewhere often use the
   401 new-style (Isar) format; to refer to their theorems in an ML script you must
   402 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
   403 
   404 * HOL: inductive package no longer splits induction rule aggressively,
   405 but only as far as specified by the introductions given; the old
   406 format may be recovered via ML function complete_split_rule or attribute
   407 'split_rule (complete)';
   408 
   409 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
   410 gfp_Tarski to gfp_unfold;
   411 
   412 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
   413 
   414 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
   415 relation); infix "^^" has been renamed "``"; infix "``" has been
   416 renamed "`"; "univalent" has been renamed "single_valued";
   417 
   418 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
   419 operation;
   420 
   421 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
   422 
   423 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
   424 
   425 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
   426 consequence, it is no longer monotonic wrt. the local goal context
   427 (which is now passed through the inductive cases);
   428 
   429 * Document preparation: renamed standard symbols \<ll> to \<lless> and
   430 \<gg> to \<ggreater>;
   431 
   432 
   433 *** Document preparation ***
   434 
   435 * \isabellestyle{NAME} selects version of Isabelle output (currently
   436 available: are "it" for near math-mode best-style output, "sl" for
   437 slanted text style, and "tt" for plain type-writer; if no
   438 \isabellestyle command is given, output is according to slanted
   439 type-writer);
   440 
   441 * support sub/super scripts (for single symbols only), input syntax is
   442 like this: "A\<^sup>*" or "A\<^sup>\<star>";
   443 
   444 * some more standard symbols; see Appendix A of the system manual for
   445 the complete list of symbols defined in isabellesym.sty;
   446 
   447 * improved isabelle style files; more abstract symbol implementation
   448 (should now use \isamath{...} and \isatext{...} in custom symbol
   449 definitions);
   450 
   451 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
   452 state; Note that presentation of goal states does not conform to
   453 actual human-readable proof documents.  Please do not include goal
   454 states into document output unless you really know what you are doing!
   455 
   456 * proper indentation of antiquoted output with proportional LaTeX
   457 fonts;
   458 
   459 * no_document ML operator temporarily disables LaTeX document
   460 generation;
   461 
   462 * isatool unsymbolize tunes sources for plain ASCII communication;
   463 
   464 
   465 *** Isar ***
   466 
   467 * Pure: Isar now suffers initial goal statements to contain unbound
   468 schematic variables (this does not conform to actual readable proof
   469 documents, due to unpredictable outcome and non-compositional proof
   470 checking); users who know what they are doing may use schematic goals
   471 for Prolog-style synthesis of proven results;
   472 
   473 * Pure: assumption method (an implicit finishing) now handles actual
   474 rules as well;
   475 
   476 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
   477 initial goal, declare "that" only as Pure intro (only for single
   478 steps); the "that" rule assumption may now be involved in implicit
   479 finishing, thus ".." becomes a feasible for trivial obtains;
   480 
   481 * Pure: default proof step now includes 'intro_classes'; thus trivial
   482 instance proofs may be performed by "..";
   483 
   484 * Pure: ?thesis / ?this / "..." now work for pure meta-level
   485 statements as well;
   486 
   487 * Pure: more robust selection of calculational rules;
   488 
   489 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
   490 rule (as well as the assumption rule);
   491 
   492 * Pure: 'thm_deps' command visualizes dependencies of theorems and
   493 lemmas, using the graph browser tool;
   494 
   495 * Pure: predict failure of "show" in interactive mode;
   496 
   497 * Pure: 'thms_containing' now takes actual terms as arguments;
   498 
   499 * HOL: improved method 'induct' --- now handles non-atomic goals
   500 (potential INCOMPATIBILITY); tuned error handling;
   501 
   502 * HOL: cases and induct rules now provide explicit hints about the
   503 number of facts to be consumed (0 for "type" and 1 for "set" rules);
   504 any remaining facts are inserted into the goal verbatim;
   505 
   506 * HOL: local contexts (aka cases) may now contain term bindings as
   507 well; the 'cases' and 'induct' methods new provide a ?case binding for
   508 the result to be shown in each case;
   509 
   510 * HOL: added 'recdef_tc' command;
   511 
   512 * isatool convert assists in eliminating legacy ML scripts;
   513 
   514 
   515 *** HOL ***
   516 
   517 * HOL/Library: a collection of generic theories to be used together
   518 with main HOL; the theory loader path already includes this directory
   519 by default; the following existing theories have been moved here:
   520 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
   521 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
   522 
   523 * HOL/Unix: "Some aspects of Unix file-system security", a typical
   524 modelling and verification task performed in Isabelle/HOL +
   525 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
   526 
   527 * HOL/Algebra: special summation operator SUM no longer exists, it has
   528 been replaced by setsum; infix 'assoc' now has priority 50 (like
   529 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
   530 'domain', this makes the theory consistent with mathematical
   531 literature;
   532 
   533 * HOL basics: added overloaded operations "inverse" and "divide"
   534 (infix "/"), syntax for generic "abs" operation, generic summation
   535 operator \<Sum>;
   536 
   537 * HOL/typedef: simplified package, provide more useful rules (see also
   538 HOL/subset.thy);
   539 
   540 * HOL/datatype: induction rule for arbitrarily branching datatypes is
   541 now expressed as a proper nested rule (old-style tactic scripts may
   542 require atomize_strip_tac to cope with non-atomic premises);
   543 
   544 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
   545 to "split_conv" (old name still available for compatibility);
   546 
   547 * HOL: improved concrete syntax for strings (e.g. allows translation
   548 rules with string literals);
   549 
   550 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
   551  and Fleuriot's mechanization of analysis, including the transcendental
   552  functions for the reals;
   553 
   554 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
   555 
   556 
   557 *** CTT ***
   558 
   559 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
   560 "lam" is displayed as TWO lambda-symbols
   561 
   562 * CTT: theory Main now available, containing everything (that is, Bool
   563 and Arith);
   564 
   565 
   566 *** General ***
   567 
   568 * Pure: the Simplifier has been implemented properly as a derived rule
   569 outside of the actual kernel (at last!); the overall performance
   570 penalty in practical applications is about 50%, while reliability of
   571 the Isabelle inference kernel has been greatly improved;
   572 
   573 * print modes "brackets" and "no_brackets" control output of nested =>
   574 (types) and ==> (props); the default behaviour is "brackets";
   575 
   576 * Provers: fast_tac (and friends) now handle actual object-logic rules
   577 as assumptions as well;
   578 
   579 * system: support Poly/ML 4.0;
   580 
   581 * system: isatool install handles KDE version 1 or 2;
   582 
   583 
   584 
   585 New in Isabelle99-1 (October 2000)
   586 ----------------------------------
   587 
   588 *** Overview of INCOMPATIBILITIES ***
   589 
   590 * HOL: simplification of natural numbers is much changed; to partly
   591 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
   592 issue the following ML commands:
   593 
   594   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
   595   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
   596 
   597 * HOL: simplification no longer dives into case-expressions; this is
   598 controlled by "t.weak_case_cong" for each datatype t;
   599 
   600 * HOL: nat_less_induct renamed to less_induct;
   601 
   602 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
   603 fixsome to patch .thy and .ML sources automatically;
   604 
   605   select_equality  -> some_equality
   606   select_eq_Ex     -> some_eq_ex
   607   selectI2EX       -> someI2_ex
   608   selectI2         -> someI2
   609   selectI          -> someI
   610   select1_equality -> some1_equality
   611   Eps_sym_eq       -> some_sym_eq_trivial
   612   Eps_eq           -> some_eq_trivial
   613 
   614 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
   615 
   616 * HOL: removed obsolete theorem binding expand_if (refer to split_if
   617 instead);
   618 
   619 * HOL: the recursion equations generated by 'recdef' are now called
   620 f.simps instead of f.rules;
   621 
   622 * HOL: qed_spec_mp now also handles bounded ALL as well;
   623 
   624 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
   625 sometimes be needed;
   626 
   627 * HOL: the constant for "f``x" is now "image" rather than "op ``";
   628 
   629 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
   630 
   631 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
   632 product is now "<*>" instead of "Times"; the lexicographic product is
   633 now "<*lex*>" instead of "**";
   634 
   635 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
   636 of main HOL, but was unused); better use HOL's datatype package;
   637 
   638 * HOL: removed "symbols" syntax for constant "override" of theory Map;
   639 the old syntax may be recovered as follows:
   640 
   641   syntax (symbols)
   642     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
   643       (infixl "\\<oplus>" 100)
   644 
   645 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   646 
   647 * HOL/ML: even fewer consts are declared as global (see theories Ord,
   648 Lfp, Gfp, WF); this only affects ML packages that refer to const names
   649 internally;
   650 
   651 * HOL and ZF: syntax for quotienting wrt an equivalence relation
   652 changed from A/r to A//r;
   653 
   654 * ZF: new treatment of arithmetic (nat & int) may break some old
   655 proofs;
   656 
   657 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
   658 rulify -> rule_format, elimify -> elim_format, ...);
   659 
   660 * Isar/Provers: intro/elim/dest attributes changed; renamed
   661 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
   662 should have to change intro!! to intro? only); replaced "delrule" by
   663 "rule del";
   664 
   665 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
   666 
   667 * Provers: strengthened force_tac by using new first_best_tac;
   668 
   669 * LaTeX document preparation: several changes of isabelle.sty (see
   670 lib/texinputs);
   671 
   672 
   673 *** Document preparation ***
   674 
   675 * formal comments (text blocks etc.) in new-style theories may now
   676 contain antiquotations of thm/prop/term/typ/text to be presented
   677 according to latex print mode; concrete syntax is like this:
   678 @{term[show_types] "f(x) = a + x"};
   679 
   680 * isatool mkdir provides easy setup of Isabelle session directories,
   681 including proper document sources;
   682 
   683 * generated LaTeX sources are now deleted after successful run
   684 (isatool document -c); may retain a copy somewhere else via -D option
   685 of isatool usedir;
   686 
   687 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
   688 style files, achieving self-contained LaTeX sources and simplifying
   689 LaTeX debugging;
   690 
   691 * old-style theories now produce (crude) LaTeX output as well;
   692 
   693 * browser info session directories are now self-contained (may be put
   694 on WWW server seperately); improved graphs of nested sessions; removed
   695 graph for 'all sessions';
   696 
   697 * several improvements in isabelle style files; \isabellestyle{it}
   698 produces fake math mode output; \isamarkupheader is now \section by
   699 default; see lib/texinputs/isabelle.sty etc.;
   700 
   701 
   702 *** Isar ***
   703 
   704 * Isar/Pure: local results and corresponding term bindings are now
   705 subject to Hindley-Milner polymorphism (similar to ML); this
   706 accommodates incremental type-inference very nicely;
   707 
   708 * Isar/Pure: new derived language element 'obtain' supports
   709 generalized existence reasoning;
   710 
   711 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
   712 support accumulation of results, without applying any rules yet;
   713 useful to collect intermediate results without explicit name
   714 references, and for use with transitivity rules with more than 2
   715 premises;
   716 
   717 * Isar/Pure: scalable support for case-analysis type proofs: new
   718 'case' language element refers to local contexts symbolically, as
   719 produced by certain proof methods; internally, case names are attached
   720 to theorems as "tags";
   721 
   722 * Isar/Pure: theory command 'hide' removes declarations from
   723 class/type/const name spaces;
   724 
   725 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
   726 indicate potential overloading;
   727 
   728 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
   729 
   730 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
   731 "{a,b,c}" instead of {a,b,c};
   732 
   733 * Isar/Pure now provides its own version of intro/elim/dest
   734 attributes; useful for building new logics, but beware of confusion
   735 with the version in Provers/classical;
   736 
   737 * Isar/Pure: the local context of (non-atomic) goals is provided via
   738 case name 'antecedent';
   739 
   740 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
   741 to the current context is now done automatically);
   742 
   743 * Isar/Pure: theory command 'method_setup' provides a simple interface
   744 for definining proof methods in ML;
   745 
   746 * Isar/Provers: intro/elim/dest attributes changed; renamed
   747 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
   748 most cases, one should have to change intro!! to intro? only);
   749 replaced "delrule" by "rule del";
   750 
   751 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
   752 'symmetric' attribute (the latter supercedes [RS sym]);
   753 
   754 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
   755 method modifier); 'simp' method: 'only:' modifier removes loopers as
   756 well (including splits);
   757 
   758 * Isar/Provers: Simplifier and Classical methods now support all kind
   759 of modifiers used in the past, including 'cong', 'iff', etc.
   760 
   761 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
   762 of Simplifier and Classical reasoner);
   763 
   764 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
   765 now support named cases; major packages (inductive, datatype, primrec,
   766 recdef) support case names and properly name parameters;
   767 
   768 * Isar/HOL: new transitivity rules for substitution in inequalities --
   769 monotonicity conditions are extracted to be proven at end of
   770 calculations;
   771 
   772 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
   773 method anyway;
   774 
   775 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
   776 split_if split_if_asm; datatype package provides theorems foo.splits =
   777 foo.split foo.split_asm for each datatype;
   778 
   779 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
   780 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
   781 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
   782 use "(cases (simplified))" method in proper proof texts);
   783 
   784 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
   785 
   786 * Isar: names of theorems etc. may be natural numbers as well;
   787 
   788 * Isar: 'pr' command: optional arguments for goals_limit and
   789 ProofContext.prems_limit; no longer prints theory contexts, but only
   790 proof states;
   791 
   792 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
   793 additional print modes to be specified; e.g. "pr(latex)" will print
   794 proof state according to the Isabelle LaTeX style;
   795 
   796 * Isar: improved support for emulating tactic scripts, including proof
   797 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
   798 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
   799 (for HOL datatypes);
   800 
   801 * Isar: simplified (more robust) goal selection of proof methods: 1st
   802 goal, all goals, or explicit goal specifier (tactic emulation); thus
   803 'proof method scripts' have to be in depth-first order;
   804 
   805 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
   806 
   807 * Isar: removed 'help' command, which hasn't been too helpful anyway;
   808 should instead use individual commands for printing items
   809 (print_commands, print_methods etc.);
   810 
   811 * Isar: added 'nothing' --- the empty list of theorems;
   812 
   813 
   814 *** HOL ***
   815 
   816 * HOL/MicroJava: formalization of a fragment of Java, together with a
   817 corresponding virtual machine and a specification of its bytecode
   818 verifier and a lightweight bytecode verifier, including proofs of
   819 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
   820 Cornelia Pusch (see also the homepage of project Bali at
   821 http://isabelle.in.tum.de/Bali/);
   822 
   823 * HOL/Algebra: new theory of rings and univariate polynomials, by
   824 Clemens Ballarin;
   825 
   826 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
   827 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
   828 Rasmussen;
   829 
   830 * HOL/Lattice: fundamental concepts of lattice theory and order
   831 structures, including duals, properties of bounds versus algebraic
   832 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
   833 Theorem for complete lattices etc.; may also serve as a demonstration
   834 for abstract algebraic reasoning using axiomatic type classes, and
   835 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
   836 
   837 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
   838 von Oheimb;
   839 
   840 * HOL/IMPP: extension of IMP with local variables and mutually
   841 recursive procedures, by David von Oheimb;
   842 
   843 * HOL/Lambda: converted into new-style theory and document;
   844 
   845 * HOL/ex/Multiquote: example of multiple nested quotations and
   846 anti-quotations -- basically a generalized version of de-Bruijn
   847 representation; very useful in avoiding lifting of operations;
   848 
   849 * HOL/record: added general record equality rule to simpset; fixed
   850 select-update simplification procedure to handle extended records as
   851 well; admit "r" as field name;
   852 
   853 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
   854 other numeric types and also as the identity of groups, rings, etc.;
   855 
   856 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
   857 Types nat and int belong to this axclass;
   858 
   859 * HOL: greatly improved simplification involving numerals of type nat, int, real:
   860    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
   861    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
   862   two terms #m*u and #n*u are replaced by #(m+n)*u
   863     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
   864   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
   865     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
   866 
   867 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
   868 powerful prover for predicate logic but knows nothing of clasets; see
   869 ex/mesontest.ML and ex/mesontest2.ML for example applications;
   870 
   871 * HOL: new version of "case_tac" subsumes both boolean case split and
   872 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
   873 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
   874 
   875 * HOL: simplification no longer dives into case-expressions: only the
   876 selector expression is simplified, but not the remaining arms; to
   877 enable full simplification of case-expressions for datatype t, you may
   878 remove t.weak_case_cong from the simpset, either globally (Delcongs
   879 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
   880 
   881 * HOL/recdef: the recursion equations generated by 'recdef' for
   882 function 'f' are now called f.simps instead of f.rules; if all
   883 termination conditions are proved automatically, these simplification
   884 rules are added to the simpset, as in primrec; rules may be named
   885 individually as well, resulting in a separate list of theorems for
   886 each equation;
   887 
   888 * HOL/While is a new theory that provides a while-combinator. It
   889 permits the definition of tail-recursive functions without the
   890 provision of a termination measure. The latter is necessary once the
   891 invariant proof rule for while is applied.
   892 
   893 * HOL: new (overloaded) notation for the set of elements below/above
   894 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
   895 
   896 * HOL: theorems impI, allI, ballI bound as "strip";
   897 
   898 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
   899 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
   900 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
   901 
   902 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   903 
   904 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
   905 main HOL, but was unused);
   906 
   907 * HOL: fewer consts declared as global (e.g. have to refer to
   908 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
   909 
   910 * HOL: tuned AST representation of nested pairs, avoiding bogus output
   911 in case of overlap with user translations (e.g. judgements over
   912 tuples); (note that the underlying logical represenation is still
   913 bogus);
   914 
   915 
   916 *** ZF ***
   917 
   918 * ZF: simplification automatically cancels common terms in arithmetic
   919 expressions over nat and int;
   920 
   921 * ZF: new treatment of nat to minimize type-checking: all operators
   922 coerce their operands to a natural number using the function natify,
   923 making the algebraic laws unconditional;
   924 
   925 * ZF: as above, for int: operators coerce their operands to an integer
   926 using the function intify;
   927 
   928 * ZF: the integer library now contains many of the usual laws for the
   929 orderings, including $<=, and monotonicity laws for $+ and $*;
   930 
   931 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
   932 simplification;
   933 
   934 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
   935 to the simplifier and classical reasoner simultaneously;
   936 
   937 
   938 *** General ***
   939 
   940 * Provers: blast_tac now handles actual object-logic rules as
   941 assumptions; note that auto_tac uses blast_tac internally as well;
   942 
   943 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
   944 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
   945 
   946 * Provers: delrules now handles destruct rules as well (no longer need
   947 explicit make_elim);
   948 
   949 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
   950   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   951 use instead the strong form,
   952   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   953 in HOL, FOL and ZF the function cla_make_elim will create such rules
   954 from destruct-rules;
   955 
   956 * Provers: Simplifier.easy_setup provides a fast path to basic
   957 Simplifier setup for new object-logics;
   958 
   959 * Pure: AST translation rules no longer require constant head on LHS;
   960 
   961 * Pure: improved name spaces: ambiguous output is qualified; support
   962 for hiding of names;
   963 
   964 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
   965 XSYMBOL_HOME; no longer need to do manual configuration in most
   966 situations;
   967 
   968 * system: compression of ML heaps images may now be controlled via -c
   969 option of isabelle and isatool usedir (currently only observed by
   970 Poly/ML);
   971 
   972 * system: isatool installfonts may handle X-Symbol fonts as well (very
   973 useful for remote X11);
   974 
   975 * system: provide TAGS file for Isabelle sources;
   976 
   977 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
   978 order;
   979 
   980 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
   981 timing flag supersedes proof_timing and Toplevel.trace;
   982 
   983 * ML: new combinators |>> and |>>> for incremental transformations
   984 with secondary results (e.g. certain theory extensions):
   985 
   986 * ML: PureThy.add_defs gets additional argument to indicate potential
   987 overloading (usually false);
   988 
   989 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
   990 results;
   991 
   992 
   993 
   994 New in Isabelle99 (October 1999)
   995 --------------------------------
   996 
   997 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   998 
   999 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  1000 are no longer simplified.  (This allows the simplifier to unfold recursive
  1001 functional programs.)  To restore the old behaviour, declare
  1002 
  1003     Delcongs [if_weak_cong];
  1004 
  1005 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  1006 complement;
  1007 
  1008 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  1009 
  1010 * HOL/datatype: mutual_induct_tac no longer exists --
  1011   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  1012 
  1013 * HOL/typedef: fixed type inference for representing set; type
  1014 arguments now have to occur explicitly on the rhs as type constraints;
  1015 
  1016 * ZF: The con_defs part of an inductive definition may no longer refer
  1017 to constants declared in the same theory;
  1018 
  1019 * HOL, ZF: the function mk_cases, generated by the inductive
  1020 definition package, has lost an argument.  To simplify its result, it
  1021 uses the default simpset instead of a supplied list of theorems.
  1022 
  1023 * HOL/List: the constructors of type list are now Nil and Cons;
  1024 
  1025 * Simplifier: the type of the infix ML functions
  1026         setSSolver addSSolver setSolver addSolver
  1027 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  1028 for packaging solvers. A solver is created via
  1029         mk_solver: string -> (thm list -> int -> tactic) -> solver
  1030 where the string argument is only a comment.
  1031 
  1032 
  1033 *** Proof tools ***
  1034 
  1035 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  1036 decision procedure for linear arithmetic. Currently it is used for
  1037 types `nat', `int', and `real' in HOL (see below); it can, should and
  1038 will be instantiated for other types and logics as well.
  1039 
  1040 * The simplifier now accepts rewrite rules with flexible heads, eg
  1041      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  1042   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  1043   matching.
  1044 
  1045 
  1046 *** General ***
  1047 
  1048 * New Isabelle/Isar subsystem provides an alternative to traditional
  1049 tactical theorem proving; together with the ProofGeneral/isar user
  1050 interface it offers an interactive environment for developing human
  1051 readable proof documents (Isar == Intelligible semi-automated
  1052 reasoning); for further information see isatool doc isar-ref,
  1053 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  1054 
  1055 * improved and simplified presentation of theories: better HTML markup
  1056 (including colors), graph views in several sizes; isatool usedir now
  1057 provides a proper interface for user theories (via -P option); actual
  1058 document preparation based on (PDF)LaTeX is available as well (for
  1059 new-style theories only); see isatool doc system for more information;
  1060 
  1061 * native support for Proof General, both for classic Isabelle and
  1062 Isabelle/Isar;
  1063 
  1064 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  1065 using the graph browser tool;
  1066 
  1067 * Isabelle manuals now also available as PDF;
  1068 
  1069 * theory loader rewritten from scratch (may not be fully
  1070 bug-compatible); old loadpath variable has been replaced by show_path,
  1071 add_path, del_path, reset_path functions; new operations such as
  1072 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  1073 isatool doc ref);
  1074 
  1075 * improved isatool install: option -k creates KDE application icon,
  1076 option -p DIR installs standalone binaries;
  1077 
  1078 * added ML_PLATFORM setting (useful for cross-platform installations);
  1079 more robust handling of platform specific ML images for SML/NJ;
  1080 
  1081 * the settings environment is now statically scoped, i.e. it is never
  1082 created again in sub-processes invoked from isabelle, isatool, or
  1083 Isabelle;
  1084 
  1085 * path element specification '~~' refers to '$ISABELLE_HOME';
  1086 
  1087 * in locales, the "assumes" and "defines" parts may be omitted if
  1088 empty;
  1089 
  1090 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  1091 long arrows);
  1092 
  1093 * new print_mode "HTML";
  1094 
  1095 * new flag show_tags controls display of tags of theorems (which are
  1096 basically just comments that may be attached by some tools);
  1097 
  1098 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  1099 mode and goal output format:
  1100 
  1101 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  1102 244c244
  1103 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  1104 ---
  1105 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  1106 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  1107 181c181
  1108 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  1109 ---
  1110 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  1111 
  1112 * function bind_thms stores lists of theorems (cf. bind_thm);
  1113 
  1114 * new shorthand tactics ftac, eatac, datac, fatac;
  1115 
  1116 * qed (and friends) now accept "" as result name; in that case the
  1117 theorem is not stored, but proper checks and presentation of the
  1118 result still apply;
  1119 
  1120 * theorem database now also indexes constants "Trueprop", "all",
  1121 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  1122 
  1123 
  1124 *** HOL ***
  1125 
  1126 ** HOL arithmetic **
  1127 
  1128 * There are now decision procedures for linear arithmetic over nat and
  1129 int:
  1130 
  1131 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  1132 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  1133 are treated as atomic; subformulae not involving type `nat' or `int'
  1134 are ignored; quantified subformulae are ignored unless they are
  1135 positive universal or negative existential. The tactic has to be
  1136 invoked by hand and can be a little bit slow. In particular, the
  1137 running time is exponential in the number of occurrences of `min' and
  1138 `max', and `-' on `nat'.
  1139 
  1140 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  1141 (negated) (in)equalities among the premises and the conclusion into
  1142 account (i.e. no compound formulae) and does not know about `min' and
  1143 `max', and `-' on `nat'. It is fast and is used automatically by the
  1144 simplifier.
  1145 
  1146 NB: At the moment, these decision procedures do not cope with mixed
  1147 nat/int formulae where the two parts interact, such as `m < n ==>
  1148 int(m) < int(n)'.
  1149 
  1150 * HOL/Numeral provides a generic theory of numerals (encoded
  1151 efficiently as bit strings); setup for types nat/int/real is in place;
  1152 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  1153 int, existing theories and proof scripts may require a few additional
  1154 type constraints;
  1155 
  1156 * integer division and remainder can now be performed on constant
  1157 arguments;
  1158 
  1159 * many properties of integer multiplication, division and remainder
  1160 are now available;
  1161 
  1162 * An interface to the Stanford Validity Checker (SVC) is available through the
  1163 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  1164 are proved automatically.  SVC must be installed separately, and its results
  1165 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  1166 invocation of the underlying oracle).  For SVC see
  1167   http://verify.stanford.edu/SVC
  1168 
  1169 * IsaMakefile: the HOL-Real target now builds an actual image;
  1170 
  1171 
  1172 ** HOL misc **
  1173 
  1174 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  1175 (in Isabelle/Isar) -- by Gertrud Bauer;
  1176 
  1177 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  1178 analysis for assembly languages with subtypes;
  1179 
  1180 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  1181 -- avoids syntactic ambiguities and treats state, transition, and
  1182 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  1183 changed syntax and (many) tactics;
  1184 
  1185 * HOL/inductive: Now also handles more general introduction rules such
  1186   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  1187   theorems are now maintained within the theory (maintained via the
  1188   "mono" attribute);
  1189 
  1190 * HOL/datatype: Now also handles arbitrarily branching datatypes
  1191   (using function types) such as
  1192 
  1193   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  1194 
  1195 * HOL/record: record_simproc (part of the default simpset) takes care
  1196 of selectors applied to updated records; record_split_tac is no longer
  1197 part of the default claset; update_defs may now be removed from the
  1198 simpset in many cases; COMPATIBILITY: old behavior achieved by
  1199 
  1200   claset_ref () := claset() addSWrapper record_split_wrapper;
  1201   Delsimprocs [record_simproc]
  1202 
  1203 * HOL/typedef: fixed type inference for representing set; type
  1204 arguments now have to occur explicitly on the rhs as type constraints;
  1205 
  1206 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  1207 names rather than an ML expression;
  1208 
  1209 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  1210 supplied later.  Program schemes can be defined, such as
  1211     "While B C s = (if B s then While B C (C s) else s)"
  1212 where the well-founded relation can be chosen after B and C have been given.
  1213 
  1214 * HOL/List: the constructors of type list are now Nil and Cons;
  1215 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  1216 course, ML tools referring to List.list.op # etc. have to be adapted;
  1217 
  1218 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  1219 disabled by default; run isabelle with option -m HOL to get back to
  1220 the original Gordon/HOL-style output;
  1221 
  1222 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  1223 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  1224 
  1225 * HOL basic syntax simplified (more orthogonal): all variants of
  1226 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  1227 Eps operator is provided as well: "SOME x. P[x]";
  1228 
  1229 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  1230 
  1231 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  1232 thus available for user theories;
  1233 
  1234 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  1235 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  1236 time;
  1237 
  1238 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  1239 several times and then mp;
  1240 
  1241 
  1242 *** LK ***
  1243 
  1244 * the notation <<...>> is now available as a notation for sequences of
  1245 formulas;
  1246 
  1247 * the simplifier is now installed
  1248 
  1249 * the axiom system has been generalized (thanks to Soren Heilmann)
  1250 
  1251 * the classical reasoner now has a default rule database
  1252 
  1253 
  1254 *** ZF ***
  1255 
  1256 * new primrec section allows primitive recursive functions to be given
  1257 directly (as in HOL) over datatypes and the natural numbers;
  1258 
  1259 * new tactics induct_tac and exhaust_tac for induction (or case
  1260 analysis) over datatypes and the natural numbers;
  1261 
  1262 * the datatype declaration of type T now defines the recursor T_rec;
  1263 
  1264 * simplification automatically does freeness reasoning for datatype
  1265 constructors;
  1266 
  1267 * automatic type-inference, with AddTCs command to insert new
  1268 type-checking rules;
  1269 
  1270 * datatype introduction rules are now added as Safe Introduction rules
  1271 to the claset;
  1272 
  1273 * the syntax "if P then x else y" is now available in addition to
  1274 if(P,x,y);
  1275 
  1276 
  1277 *** Internal programming interfaces ***
  1278 
  1279 * tuned simplifier trace output; new flag debug_simp;
  1280 
  1281 * structures Vartab / Termtab (instances of TableFun) offer efficient
  1282 tables indexed by indexname_ord / term_ord (compatible with aconv);
  1283 
  1284 * AxClass.axclass_tac lost the theory argument;
  1285 
  1286 * tuned current_goals_markers semantics: begin / end goal avoids
  1287 printing empty lines;
  1288 
  1289 * removed prs and prs_fn hook, which was broken because it did not
  1290 include \n in its semantics, forcing writeln to add one
  1291 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  1292 string -> unit if you really want to output text without newline;
  1293 
  1294 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  1295 plain output, interface builders may have to enable 'isabelle_font'
  1296 mode to get Isabelle font glyphs as before;
  1297 
  1298 * refined token_translation interface; INCOMPATIBILITY: output length
  1299 now of type real instead of int;
  1300 
  1301 * theory loader actions may be traced via new ThyInfo.add_hook
  1302 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  1303 your own database of information attached to *whole* theories -- as
  1304 opposed to intra-theory data slots offered via TheoryDataFun;
  1305 
  1306 * proper handling of dangling sort hypotheses (at last!);
  1307 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  1308 extra sort hypotheses that can be witnessed from the type signature;
  1309 the force_strip_shyps flag is gone, any remaining shyps are simply
  1310 left in the theorem (with a warning issued by strip_shyps_warning);
  1311 
  1312 
  1313 
  1314 New in Isabelle98-1 (October 1998)
  1315 ----------------------------------
  1316 
  1317 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1318 
  1319 * several changes of automated proof tools;
  1320 
  1321 * HOL: major changes to the inductive and datatype packages, including
  1322 some minor incompatibilities of theory syntax;
  1323 
  1324 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  1325 called `inj_on';
  1326 
  1327 * HOL: removed duplicate thms in Arith:
  1328   less_imp_add_less  should be replaced by  trans_less_add1
  1329   le_imp_add_le      should be replaced by  trans_le_add1
  1330 
  1331 * HOL: unary minus is now overloaded (new type constraints may be
  1332 required);
  1333 
  1334 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  1335 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  1336 now taken as an integer constant.
  1337 
  1338 * Pure: ML function 'theory_of' renamed to 'theory';
  1339 
  1340 
  1341 *** Proof tools ***
  1342 
  1343 * Simplifier:
  1344   1. Asm_full_simp_tac is now more aggressive.
  1345      1. It will sometimes reorient premises if that increases their power to
  1346         simplify.
  1347      2. It does no longer proceed strictly from left to right but may also
  1348         rotate premises to achieve further simplification.
  1349      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  1350      old Asm_full_simp_tac in that it does not rotate premises.
  1351   2. The simplifier now knows a little bit about nat-arithmetic.
  1352 
  1353 * Classical reasoner: wrapper mechanism for the classical reasoner now
  1354 allows for selected deletion of wrappers, by introduction of names for
  1355 wrapper functionals.  This implies that addbefore, addSbefore,
  1356 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  1357 and that adding two tactics with the same name overwrites the first
  1358 one (emitting a warning).
  1359   type wrapper = (int -> tactic) -> (int -> tactic)
  1360   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  1361   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  1362   delWrapper, delSWrapper: claset *  string            -> claset
  1363   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  1364 
  1365 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  1366 semantics; addbefore now affects only the unsafe part of step_tac
  1367 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  1368 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  1369 by Force_tac;
  1370 
  1371 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  1372 compWrapper; added safe wrapper (and access functions for it);
  1373 
  1374 * HOL/split_all_tac is now much faster and fails if there is nothing
  1375 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  1376 and the names of the automatically generated variables have changed.
  1377 split_all_tac has moved within claset() from unsafe wrappers to safe
  1378 wrappers, which means that !!-bound variables are split much more
  1379 aggressively, and safe_tac and clarify_tac now split such variables.
  1380 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  1381 Note: the same holds for record_split_tac, which does the job of
  1382 split_all_tac for record fields.
  1383 
  1384 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  1385 permanently to the default simpset using Addsplits just like
  1386 Addsimps. They can be removed via Delsplits just like
  1387 Delsimps. Lower-case versions are also available.
  1388 
  1389 * HOL/Simplifier: The rule split_if is now part of the default
  1390 simpset. This means that the simplifier will eliminate all occurrences
  1391 of if-then-else in the conclusion of a goal. To prevent this, you can
  1392 either remove split_if completely from the default simpset by
  1393 `Delsplits [split_if]' or remove it in a specific call of the
  1394 simplifier using `... delsplits [split_if]'.  You can also add/delete
  1395 other case splitting rules to/from the default simpset: every datatype
  1396 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  1397 t is the name of the datatype).
  1398 
  1399 * Classical reasoner / Simplifier combination: new force_tac (and
  1400 derivatives Force_tac, force) combines rewriting and classical
  1401 reasoning (and whatever other tools) similarly to auto_tac, but is
  1402 aimed to solve the given subgoal completely.
  1403 
  1404 
  1405 *** General ***
  1406 
  1407 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  1408 and `goalw': the theory is no longer needed as an explicit argument -
  1409 the current theory context is used; assumptions are no longer returned
  1410 at the ML-level unless one of them starts with ==> or !!; it is
  1411 recommended to convert to these new commands using isatool fixgoal
  1412 (backup your sources first!);
  1413 
  1414 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  1415 the current theory context, and 'theory' to lookup stored theories;
  1416 
  1417 * new theory section 'locale' for declaring constants, assumptions and
  1418 definitions that have local scope;
  1419 
  1420 * new theory section 'nonterminals' for purely syntactic types;
  1421 
  1422 * new theory section 'setup' for generic ML setup functions
  1423 (e.g. package initialization);
  1424 
  1425 * the distribution now includes Isabelle icons: see
  1426 lib/logo/isabelle-{small,tiny}.xpm;
  1427 
  1428 * isatool install - install binaries with absolute references to
  1429 ISABELLE_HOME/bin;
  1430 
  1431 * isatool logo -- create instances of the Isabelle logo (as EPS);
  1432 
  1433 * print mode 'emacs' reserved for Isamode;
  1434 
  1435 * support multiple print (ast) translations per constant name;
  1436 
  1437 * theorems involving oracles are now printed with a suffixed [!];
  1438 
  1439 
  1440 *** HOL ***
  1441 
  1442 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  1443 
  1444 * HOL/inductive package reorganized and improved: now supports mutual
  1445 definitions such as
  1446 
  1447   inductive EVEN ODD
  1448     intrs
  1449       null "0 : EVEN"
  1450       oddI "n : EVEN ==> Suc n : ODD"
  1451       evenI "n : ODD ==> Suc n : EVEN"
  1452 
  1453 new theorem list "elims" contains an elimination rule for each of the
  1454 recursive sets; inductive definitions now handle disjunctive premises
  1455 correctly (also ZF);
  1456 
  1457 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  1458 "mutual_induct" no longer exists - the induction rule is always
  1459 contained in "induct";
  1460 
  1461 
  1462 * HOL/datatype package re-implemented and greatly improved: now
  1463 supports mutually recursive datatypes such as
  1464 
  1465   datatype
  1466     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  1467             | SUM ('a aexp) ('a aexp)
  1468             | DIFF ('a aexp) ('a aexp)
  1469             | NUM 'a
  1470   and
  1471     'a bexp = LESS ('a aexp) ('a aexp)
  1472             | AND ('a bexp) ('a bexp)
  1473             | OR ('a bexp) ('a bexp)
  1474 
  1475 as well as indirectly recursive datatypes such as
  1476 
  1477   datatype
  1478     ('a, 'b) term = Var 'a
  1479                   | App 'b ((('a, 'b) term) list)
  1480 
  1481 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  1482 induction on mutually / indirectly recursive datatypes.
  1483 
  1484 Primrec equations are now stored in theory and can be accessed via
  1485 <function_name>.simps.
  1486 
  1487 INCOMPATIBILITIES:
  1488 
  1489   - Theories using datatypes must now have theory Datatype as an
  1490     ancestor.
  1491   - The specific <typename>.induct_tac no longer exists - use the
  1492     generic induct_tac instead.
  1493   - natE has been renamed to nat.exhaust - use exhaust_tac
  1494     instead of res_inst_tac ... natE. Note that the variable
  1495     names in nat.exhaust differ from the names in natE, this
  1496     may cause some "fragile" proofs to fail.
  1497   - The theorems split_<typename>_case and split_<typename>_case_asm
  1498     have been renamed to <typename>.split and <typename>.split_asm.
  1499   - Since default sorts of type variables are now handled correctly,
  1500     some datatype definitions may have to be annotated with explicit
  1501     sort constraints.
  1502   - Primrec definitions no longer require function name and type
  1503     of recursive argument.
  1504 
  1505 Consider using isatool fixdatatype to adapt your theories and proof
  1506 scripts to the new package (backup your sources first!).
  1507 
  1508 
  1509 * HOL/record package: considerably improved implementation; now
  1510 includes concrete syntax for record types, terms, updates; theorems
  1511 for surjective pairing and splitting !!-bound record variables; proof
  1512 support is as follows:
  1513 
  1514   1) standard conversions (selectors or updates applied to record
  1515 constructor terms) are part of the standard simpset;
  1516 
  1517   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  1518 made part of standard simpset and claset via addIffs;
  1519 
  1520   3) a tactic for record field splitting (record_split_tac) is part of
  1521 the standard claset (addSWrapper);
  1522 
  1523 To get a better idea about these rules you may retrieve them via
  1524 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  1525 the name of your record type.
  1526 
  1527 The split tactic 3) conceptually simplifies by the following rule:
  1528 
  1529   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  1530 
  1531 Thus any record variable that is bound by meta-all will automatically
  1532 blow up into some record constructor term, consequently the
  1533 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  1534 solve record problems automatically.
  1535 
  1536 
  1537 * reorganized the main HOL image: HOL/Integ and String loaded by
  1538 default; theory Main includes everything;
  1539 
  1540 * automatic simplification of integer sums and comparisons, using cancellation;
  1541 
  1542 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  1543 
  1544 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  1545 
  1546 * many new identities for unions, intersections, set difference, etc.;
  1547 
  1548 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  1549 called split_if, split_split, split_sum_case and split_nat_case (to go
  1550 with add/delsplits);
  1551 
  1552 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  1553 (?x::unit) = (); this is made part of the default simpset, which COULD
  1554 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  1555 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  1556 unit_abs_eta_conv is added in order to counter the effect of
  1557 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  1558 %u.f();
  1559 
  1560 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  1561 makes more sense);
  1562 
  1563 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1564   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1565   disjointness reasoning but breaking a few old proofs.
  1566 
  1567 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  1568 to 'converse' from 'inverse' (for compatibility with ZF and some
  1569 literature);
  1570 
  1571 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  1572 the well-founded relation;
  1573 
  1574 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  1575     Compl A.  The "Compl" syntax remains available as input syntax for this
  1576     release ONLY.
  1577 
  1578 * HOL/Update: new theory of function updates:
  1579     f(a:=b) == %x. if x=a then b else f x
  1580 may also be iterated as in f(a:=b,c:=d,...);
  1581 
  1582 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  1583 
  1584 * HOL/List:
  1585   - new function list_update written xs[i:=v] that updates the i-th
  1586     list position. May also be iterated as in xs[i:=a,j:=b,...].
  1587   - new function `upt' written [i..j(] which generates the list
  1588     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  1589     bound write [i..j], which is a shorthand for [i..j+1(].
  1590   - new lexicographic orderings and corresponding wellfoundedness theorems.
  1591 
  1592 * HOL/Arith:
  1593   - removed 'pred' (predecessor) function;
  1594   - generalized some theorems about n-1;
  1595   - many new laws about "div" and "mod";
  1596   - new laws about greatest common divisors (see theory ex/Primes);
  1597 
  1598 * HOL/Relation: renamed the relational operator r^-1 "converse"
  1599 instead of "inverse";
  1600 
  1601 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  1602   of the multiset ordering;
  1603 
  1604 * directory HOL/Real: a construction of the reals using Dedekind cuts
  1605   (not included by default);
  1606 
  1607 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  1608 
  1609 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  1610   programs, i.e. different program variables may have different types.
  1611 
  1612 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1613   [previously, this check worked only if the rewrite rule was unconditional]
  1614   Now rew can involve either definitions or equalities (either == or =).
  1615 
  1616 
  1617 *** ZF ***
  1618 
  1619 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  1620   only the theorems proved on ZF.ML;
  1621 
  1622 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1623   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1624   disjointness reasoning but breaking a few old proofs.
  1625 
  1626 * ZF/Update: new theory of function updates
  1627     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  1628   may also be iterated as in f(a:=b,c:=d,...);
  1629 
  1630 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  1631 
  1632 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1633   [previously, this check worked only if the rewrite rule was unconditional]
  1634   Now rew can involve either definitions or equalities (either == or =).
  1635 
  1636 * case_tac provided for compatibility with HOL
  1637     (like the old excluded_middle_tac, but with subgoals swapped)
  1638 
  1639 
  1640 *** Internal programming interfaces ***
  1641 
  1642 * Pure: several new basic modules made available for general use, see
  1643 also src/Pure/README;
  1644 
  1645 * improved the theory data mechanism to support encapsulation (data
  1646 kind name replaced by private Object.kind, acting as authorization
  1647 key); new type-safe user interface via functor TheoryDataFun; generic
  1648 print_data function becomes basically useless;
  1649 
  1650 * removed global_names compatibility flag -- all theory declarations
  1651 are qualified by default;
  1652 
  1653 * module Pure/Syntax now offers quote / antiquote translation
  1654 functions (useful for Hoare logic etc. with implicit dependencies);
  1655 see HOL/ex/Antiquote for an example use;
  1656 
  1657 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  1658 cterm -> thm;
  1659 
  1660 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  1661 subgoal;
  1662 
  1663 * Display.print_goals function moved to Locale.print_goals;
  1664 
  1665 * standard print function for goals supports current_goals_markers
  1666 variable for marking begin of proof, end of proof, start of goal; the
  1667 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  1668 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  1669 for example;
  1670 
  1671 
  1672 
  1673 New in Isabelle98 (January 1998)
  1674 --------------------------------
  1675 
  1676 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1677 
  1678 * changed lexical syntax of terms / types: dots made part of long
  1679 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  1680 
  1681 * simpset (and claset) reference variable replaced by functions
  1682 simpset / simpset_ref;
  1683 
  1684 * no longer supports theory aliases (via merge) and non-trivial
  1685 implicit merge of thms' signatures;
  1686 
  1687 * most internal names of constants changed due to qualified names;
  1688 
  1689 * changed Pure/Sequence interface (see Pure/seq.ML);
  1690 
  1691 
  1692 *** General Changes ***
  1693 
  1694 * hierachically structured name spaces (for consts, types, axms, thms
  1695 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  1696 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  1697 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  1698 long_names for fully qualified output names; NOTE: ML programs
  1699 (special tactics, packages etc.) referring to internal names may have
  1700 to be adapted to cope with fully qualified names; in case of severe
  1701 backward campatibility problems try setting 'global_names' at compile
  1702 time to have enrything declared within a flat name space; one may also
  1703 fine tune name declarations in theories via the 'global' and 'local'
  1704 section;
  1705 
  1706 * reimplemented the implicit simpset and claset using the new anytype
  1707 data filed in signatures; references simpset:simpset ref etc. are
  1708 replaced by functions simpset:unit->simpset and
  1709 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  1710 to patch your ML files accordingly;
  1711 
  1712 * HTML output now includes theory graph data for display with Java
  1713 applet or isatool browser; data generated automatically via isatool
  1714 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  1715 
  1716 * defs may now be conditional; improved rewrite_goals_tac to handle
  1717 conditional equations;
  1718 
  1719 * defs now admits additional type arguments, using TYPE('a) syntax;
  1720 
  1721 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  1722 creates a new theory node; implicit merge of thms' signatures is
  1723 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  1724 transfer:theory->thm->thm in (rare) cases;
  1725 
  1726 * improved handling of draft signatures / theories; draft thms (and
  1727 ctyps, cterms) are automatically promoted to real ones;
  1728 
  1729 * slightly changed interfaces for oracles: admit many per theory, named
  1730 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  1731 
  1732 * print_goals: optional output of const types (set show_consts and
  1733 show_types);
  1734 
  1735 * improved output of warnings (###) and errors (***);
  1736 
  1737 * subgoal_tac displays a warning if the new subgoal has type variables;
  1738 
  1739 * removed old README and Makefiles;
  1740 
  1741 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  1742 
  1743 * removed obsolete init_pps and init_database;
  1744 
  1745 * deleted the obsolete tactical STATE, which was declared by
  1746     fun STATE tacfun st = tacfun st st;
  1747 
  1748 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  1749 (which abbreviates $HOME);
  1750 
  1751 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  1752 use isatool fixseq to adapt your ML programs (this works for fully
  1753 qualified references to the Sequence structure only!);
  1754 
  1755 * use_thy no longer requires writable current directory; it always
  1756 reloads .ML *and* .thy file, if either one is out of date;
  1757 
  1758 
  1759 *** Classical Reasoner ***
  1760 
  1761 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  1762 tactics that use classical reasoning to simplify a subgoal without
  1763 splitting it into several subgoals;
  1764 
  1765 * Safe_tac: like safe_tac but uses the default claset;
  1766 
  1767 
  1768 *** Simplifier ***
  1769 
  1770 * added simplification meta rules:
  1771     (asm_)(full_)simplify: simpset -> thm -> thm;
  1772 
  1773 * simplifier.ML no longer part of Pure -- has to be loaded by object
  1774 logics (again);
  1775 
  1776 * added prems argument to simplification procedures;
  1777 
  1778 * HOL, FOL, ZF: added infix function `addsplits':
  1779   instead of `<simpset> setloop (split_tac <thms>)'
  1780   you can simply write `<simpset> addsplits <thms>'
  1781 
  1782 
  1783 *** Syntax ***
  1784 
  1785 * TYPE('a) syntax for type reflection terms;
  1786 
  1787 * no longer handles consts with name "" -- declare as 'syntax' instead;
  1788 
  1789 * pretty printer: changed order of mixfix annotation preference (again!);
  1790 
  1791 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  1792 
  1793 
  1794 *** HOL ***
  1795 
  1796 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1797   with `addloop' of the simplifier to faciliate case splitting in premises.
  1798 
  1799 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  1800 
  1801 * HOL/Auth: new protocol proofs including some for the Internet
  1802   protocol TLS;
  1803 
  1804 * HOL/Map: new theory of `maps' a la VDM;
  1805 
  1806 * HOL/simplifier: simplification procedures nat_cancel_sums for
  1807 cancelling out common nat summands from =, <, <= (in)equalities, or
  1808 differences; simplification procedures nat_cancel_factor for
  1809 cancelling common factor from =, <, <= (in)equalities over natural
  1810 sums; nat_cancel contains both kinds of procedures, it is installed by
  1811 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  1812 
  1813 * HOL/simplifier: terms of the form
  1814   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  1815   are rewritten to
  1816   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  1817   and those of the form
  1818   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  1819   are rewritten to
  1820   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  1821 
  1822 * HOL/datatype
  1823   Each datatype `t' now comes with a theorem `split_t_case' of the form
  1824 
  1825   P(t_case f1 ... fn x) =
  1826      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  1827         ...
  1828        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  1829      )
  1830 
  1831   and a theorem `split_t_case_asm' of the form
  1832 
  1833   P(t_case f1 ... fn x) =
  1834     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  1835         ...
  1836        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  1837      )
  1838   which can be added to a simpset via `addsplits'. The existing theorems
  1839   expand_list_case and expand_option_case have been renamed to
  1840   split_list_case and split_option_case.
  1841 
  1842 * HOL/Arithmetic:
  1843   - `pred n' is automatically converted to `n-1'.
  1844     Users are strongly encouraged not to use `pred' any longer,
  1845     because it will disappear altogether at some point.
  1846   - Users are strongly encouraged to write "0 < n" rather than
  1847     "n ~= 0". Theorems and proof tools have been modified towards this
  1848     `standard'.
  1849 
  1850 * HOL/Lists:
  1851   the function "set_of_list" has been renamed "set" (and its theorems too);
  1852   the function "nth" now takes its arguments in the reverse order and
  1853   has acquired the infix notation "!" as in "xs!n".
  1854 
  1855 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  1856 
  1857 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  1858   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  1859 
  1860 * HOL/record: extensible records with schematic structural subtyping
  1861 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  1862 still lacks various theorems and concrete record syntax;
  1863 
  1864 
  1865 *** HOLCF ***
  1866 
  1867 * removed "axioms" and "generated by" sections;
  1868 
  1869 * replaced "ops" section by extended "consts" section, which is capable of
  1870   handling the continuous function space "->" directly;
  1871 
  1872 * domain package:
  1873   . proves theorems immediately and stores them in the theory,
  1874   . creates hierachical name space,
  1875   . now uses normal mixfix annotations (instead of cinfix...),
  1876   . minor changes to some names and values (for consistency),
  1877   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  1878   . separator between mutual domain defs: changed "," to "and",
  1879   . improved handling of sort constraints;  now they have to
  1880     appear on the left-hand side of the equations only;
  1881 
  1882 * fixed LAM <x,y,zs>.b syntax;
  1883 
  1884 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  1885 adm (%x. P (t x)), where P is chainfinite and t continuous;
  1886 
  1887 
  1888 *** FOL and ZF ***
  1889 
  1890 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1891   with `addloop' of the simplifier to faciliate case splitting in premises.
  1892 
  1893 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  1894 in HOL, they strip ALL and --> from proved theorems;
  1895 
  1896 
  1897 
  1898 New in Isabelle94-8 (May 1997)
  1899 ------------------------------
  1900 
  1901 *** General Changes ***
  1902 
  1903 * new utilities to build / run / maintain Isabelle etc. (in parts
  1904 still somewhat experimental); old Makefiles etc. still functional;
  1905 
  1906 * new 'Isabelle System Manual';
  1907 
  1908 * INSTALL text, together with ./configure and ./build scripts;
  1909 
  1910 * reimplemented type inference for greater efficiency, better error
  1911 messages and clean internal interface;
  1912 
  1913 * prlim command for dealing with lots of subgoals (an easier way of
  1914 setting goals_limit);
  1915 
  1916 
  1917 *** Syntax ***
  1918 
  1919 * supports alternative (named) syntax tables (parser and pretty
  1920 printer); internal interface is provided by add_modesyntax(_i);
  1921 
  1922 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  1923 be used in conjunction with the Isabelle symbol font; uses the
  1924 "symbols" syntax table;
  1925 
  1926 * added token_translation interface (may translate name tokens in
  1927 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  1928 the current print_mode); IMPORTANT: user print translation functions
  1929 are responsible for marking newly introduced bounds
  1930 (Syntax.mark_boundT);
  1931 
  1932 * token translations for modes "xterm" and "xterm_color" that display
  1933 names in bold, underline etc. or colors (which requires a color
  1934 version of xterm);
  1935 
  1936 * infixes may now be declared with names independent of their syntax;
  1937 
  1938 * added typed_print_translation (like print_translation, but may
  1939 access type of constant);
  1940 
  1941 
  1942 *** Classical Reasoner ***
  1943 
  1944 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  1945 some limitations.  Blast_tac...
  1946   + ignores addss, addbefore, addafter; this restriction is intrinsic
  1947   + ignores elimination rules that don't have the correct format
  1948         (the conclusion MUST be a formula variable)
  1949   + ignores types, which can make HOL proofs fail
  1950   + rules must not require higher-order unification, e.g. apply_type in ZF
  1951     [message "Function Var's argument not a bound variable" relates to this]
  1952   + its proof strategy is more general but can actually be slower
  1953 
  1954 * substitution with equality assumptions no longer permutes other
  1955 assumptions;
  1956 
  1957 * minor changes in semantics of addafter (now called addaltern); renamed
  1958 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  1959 (and access functions for it);
  1960 
  1961 * improved combination of classical reasoner and simplifier:
  1962   + functions for handling clasimpsets
  1963   + improvement of addss: now the simplifier is called _after_ the
  1964     safe steps.
  1965   + safe variant of addss called addSss: uses safe simplifications
  1966     _during_ the safe steps. It is more complete as it allows multiple
  1967     instantiations of unknowns (e.g. with slow_tac).
  1968 
  1969 *** Simplifier ***
  1970 
  1971 * added interface for simplification procedures (functions that
  1972 produce *proven* rewrite rules on the fly, depending on current
  1973 redex);
  1974 
  1975 * ordering on terms as parameter (used for ordered rewriting);
  1976 
  1977 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  1978 
  1979 * the solver is now split into a safe and an unsafe part.
  1980 This should be invisible for the normal user, except that the
  1981 functions setsolver and addsolver have been renamed to setSolver and
  1982 addSolver; added safe_asm_full_simp_tac;
  1983 
  1984 
  1985 *** HOL ***
  1986 
  1987 * a generic induction tactic `induct_tac' which works for all datatypes and
  1988 also for type `nat';
  1989 
  1990 * a generic case distinction tactic `exhaust_tac' which works for all
  1991 datatypes and also for type `nat';
  1992 
  1993 * each datatype comes with a function `size';
  1994 
  1995 * patterns in case expressions allow tuple patterns as arguments to
  1996 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  1997 
  1998 * primrec now also works with type nat;
  1999 
  2000 * recdef: a new declaration form, allows general recursive functions to be
  2001 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  2002 
  2003 * the constant for negation has been renamed from "not" to "Not" to
  2004 harmonize with FOL, ZF, LK, etc.;
  2005 
  2006 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  2007 infinite lists;
  2008 
  2009 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  2010 
  2011 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  2012 problems in commutative rings, using axiomatic type classes for + and *;
  2013 
  2014 * more examples in HOL/MiniML and HOL/Auth;
  2015 
  2016 * more default rewrite rules for quantifiers, union/intersection;
  2017 
  2018 * a new constant `arbitrary == @x.False';
  2019 
  2020 * HOLCF/IOA replaces old HOL/IOA;
  2021 
  2022 * HOLCF changes: derived all rules and arities
  2023   + axiomatic type classes instead of classes
  2024   + typedef instead of faking type definitions
  2025   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  2026   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  2027   + eliminated the types void, one, tr
  2028   + use unit lift and bool lift (with translations) instead of one and tr
  2029   + eliminated blift from Lift3.thy (use Def instead of blift)
  2030   all eliminated rules are derived as theorems --> no visible changes ;
  2031 
  2032 
  2033 *** ZF ***
  2034 
  2035 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  2036 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  2037 as ZF_cs addSIs [equalityI];
  2038 
  2039 
  2040 
  2041 New in Isabelle94-7 (November 96)
  2042 ---------------------------------
  2043 
  2044 * allowing negative levels (as offsets) in prlev and choplev;
  2045 
  2046 * super-linear speedup for large simplifications;
  2047 
  2048 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  2049 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  2050 FAIL); can suppress it using the command Delsimps (ex_simps @
  2051 all_simps); De Morgan laws are also now included, by default;
  2052 
  2053 * improved printing of ==>  :  ~:
  2054 
  2055 * new object-logic "Sequents" adds linear logic, while replacing LK
  2056 and Modal (thanks to Sara Kalvala);
  2057 
  2058 * HOL/Auth: correctness proofs for authentication protocols;
  2059 
  2060 * HOL: new auto_tac combines rewriting and classical reasoning (many
  2061 examples on HOL/Auth);
  2062 
  2063 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  2064 the rewriter and classical reasoner simultaneously;
  2065 
  2066 * function uresult no longer returns theorems in "standard" format;
  2067 regain previous version by: val uresult = standard o uresult;
  2068 
  2069 
  2070 
  2071 New in Isabelle94-6
  2072 -------------------
  2073 
  2074 * oracles -- these establish an interface between Isabelle and trusted
  2075 external reasoners, which may deliver results as theorems;
  2076 
  2077 * proof objects (in particular record all uses of oracles);
  2078 
  2079 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  2080 
  2081 * "constdefs" section in theory files;
  2082 
  2083 * "primrec" section (HOL) no longer requires names;
  2084 
  2085 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  2086 
  2087 
  2088 
  2089 New in Isabelle94-5
  2090 -------------------
  2091 
  2092 * reduced space requirements;
  2093 
  2094 * automatic HTML generation from theories;
  2095 
  2096 * theory files no longer require "..." (quotes) around most types;
  2097 
  2098 * new examples, including two proofs of the Church-Rosser theorem;
  2099 
  2100 * non-curried (1994) version of HOL is no longer distributed;
  2101 
  2102 
  2103 
  2104 New in Isabelle94-4
  2105 -------------------
  2106 
  2107 * greatly reduced space requirements;
  2108 
  2109 * theory files (.thy) no longer require \...\ escapes at line breaks;
  2110 
  2111 * searchable theorem database (see the section "Retrieving theorems" on
  2112 page 8 of the Reference Manual);
  2113 
  2114 * new examples, including Grabczewski's monumental case study of the
  2115 Axiom of Choice;
  2116 
  2117 * The previous version of HOL renamed to Old_HOL;
  2118 
  2119 * The new version of HOL (previously called CHOL) uses a curried syntax
  2120 for functions.  Application looks like f a b instead of f(a,b);
  2121 
  2122 * Mutually recursive inductive definitions finally work in HOL;
  2123 
  2124 * In ZF, pattern-matching on tuples is now available in all abstractions and
  2125 translates to the operator "split";
  2126 
  2127 
  2128 
  2129 New in Isabelle94-3
  2130 -------------------
  2131 
  2132 * new infix operator, addss, allowing the classical reasoner to
  2133 perform simplification at each step of its search.  Example:
  2134         fast_tac (cs addss ss)
  2135 
  2136 * a new logic, CHOL, the same as HOL, but with a curried syntax
  2137 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  2138 look like (a,b) instead of <a,b>;
  2139 
  2140 * PLEASE NOTE: CHOL will eventually replace HOL!
  2141 
  2142 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  2143 It translates to the operator "split".  A new theory of integers is available;
  2144 
  2145 * In ZF, integer numerals now denote two's-complement binary integers.
  2146 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  2147 
  2148 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  2149 of the Axiom of Choice;
  2150 
  2151 
  2152 
  2153 New in Isabelle94-2
  2154 -------------------
  2155 
  2156 * Significantly faster resolution;
  2157 
  2158 * the different sections in a .thy file can now be mixed and repeated
  2159 freely;
  2160 
  2161 * Database of theorems for FOL, HOL and ZF.  New
  2162 commands including qed, qed_goal and bind_thm store theorems in the database.
  2163 
  2164 * Simple database queries: return a named theorem (get_thm) or all theorems of
  2165 a given theory (thms_of), or find out what theory a theorem was proved in
  2166 (theory_of_thm);
  2167 
  2168 * Bugs fixed in the inductive definition and datatype packages;
  2169 
  2170 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  2171 and HOL_dup_cs obsolete;
  2172 
  2173 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  2174 have been removed;
  2175 
  2176 * Simpler definition of function space in ZF;
  2177 
  2178 * new results about cardinal and ordinal arithmetic in ZF;
  2179 
  2180 * 'subtype' facility in HOL for introducing new types as subsets of existing
  2181 types;
  2182 
  2183 
  2184 $Id$