NEWS
author wenzelm
Wed Jan 09 17:42:49 2002 +0100 (2002-01-09)
changeset 12690 ac3fa7c05e5a
parent 12622 7592926925d4
child 12707 4013be8572c5
permissions -rw-r--r--
* added \<euro> symbol;
* HOL-Hyperreal is now a logic image;
* isatool latex no longer depends on changed TEXINPUTS;
     1 
     2 Isabelle NEWS -- history user-relevant changes
     3 ==============================================
     4 
     5 New in Isabelle2001 (December 2001)
     6 -----------------------------------
     7 
     8 *** Document preparation ***
     9 
    10 * greatly simplified document preparation setup, including more
    11 graceful interpretation of isatool usedir -i/-d/-D options, and more
    12 instructive isatool mkdir; users should basically be able to get
    13 started with "isatool mkdir Test && isatool make";
    14 
    15 * theory dependency graph may now be incorporated into documents;
    16 isatool usedir -g true will produce session_graph.eps/.pdf for use
    17 with \includegraphics of LaTeX;
    18 
    19 * proper spacing of consecutive markup elements, especially text
    20 blocks after section headings;
    21 
    22 * support bold style (for single symbols only), input syntax is like
    23 this: "\<^bold>\<alpha>" or "\<^bold>A";
    24 
    25 * \<bullet> is now output as bold \cdot by default, which looks much
    26 better in printed text;
    27 
    28 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
    29 note that these symbols are currently unavailable in Proof General /
    30 X-Symbol; added \<euro> symbol;
    31 
    32 * isatool latex no longer depends on changed TEXINPUTS, instead
    33 isatool document copies the Isabelle style files to the target
    34 location;
    35 
    36 
    37 *** Isar ***
    38 
    39 * Pure/Provers: improved proof by cases and induction;
    40   - 'case' command admits impromptu naming of parameters (such as
    41     "case (Suc n)");
    42   - 'induct' method divinates rule instantiation from the inductive
    43     claim; no longer requires excessive ?P bindings for proper
    44     instantiation of cases;
    45   - 'induct' method properly enumerates all possibilities of set/type
    46     rules; as a consequence facts may be also passed through *type*
    47     rules without further ado;
    48   - 'induct' method now derives symbolic cases from the *rulified*
    49     rule (before it used to rulify cases stemming from the internal
    50     atomized version); this means that the context of a non-atomic
    51     statement becomes is included in the hypothesis, avoiding the
    52     slightly cumbersome show "PROP ?case" form;
    53   - 'induct' may now use elim-style induction rules without chaining
    54     facts, using ``missing'' premises from the goal state; this allows
    55     rules stemming from inductive sets to be applied in unstructured
    56     scripts, while still benefitting from proper handling of non-atomic
    57     statements; NB: major inductive premises need to be put first, all
    58     the rest of the goal is passed through the induction;
    59   - 'induct' proper support for mutual induction involving non-atomic
    60     rule statements (uses the new concept of simultaneous goals, see
    61     below);
    62   - removed obsolete "(simplified)" and "(stripped)" options of methods;
    63   - added 'print_induct_rules' (covered by help item in Proof General > 3.3);
    64   - moved induct/cases attributes to Pure, methods to Provers;
    65   - generic method setup instantiated for FOL and HOL;
    66 
    67 * Pure: support multiple simultaneous goal statements, for example
    68 "have a: A and b: B" (same for 'theorem' etc.); being a pure
    69 meta-level mechanism, this acts as if several individual goals had
    70 been stated separately; in particular common proof methods need to be
    71 repeated in order to cover all claims; note that a single elimination
    72 step is *not* sufficient to establish the two conjunctions, so this
    73 fails:
    74 
    75   assume "A & B" then have A and B ..   (*".." fails*)
    76 
    77 better use "obtain" in situations as above; alternative refer to
    78 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
    79 
    80 * Pure: proper integration with ``locales''; unlike the original
    81 version by Florian Kammüller, Isar locales package high-level proof
    82 contexts rather than raw logical ones (e.g. we admit to include
    83 attributes everywhere); operations on locales include merge and
    84 rename; e.g. see HOL/ex/Locales.thy;
    85 
    86 * Pure: theory goals now support ad-hoc contexts, which are discharged
    87 in the result, as in ``lemma (assumes A and B) K: A .''; syntax
    88 coincides with that of a locale body;
    89 
    90 * Pure: renamed "antecedent" case to "rule_context";
    91 
    92 * Pure: added 'corollary' command;
    93 
    94 * Pure: fixed 'token_translation' command;
    95 
    96 * Pure: removed obsolete 'exported' attribute;
    97 
    98 * Pure: dummy pattern "_" in is/let is now automatically lifted over
    99 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
   100 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
   101 
   102 * Pure: method 'atomize' presents local goal premises as object-level
   103 statements (atomic meta-level propositions); setup controlled via
   104 rewrite rules declarations of 'atomize' attribute; example
   105 application: 'induct' method with proper rule statements in improper
   106 proof *scripts*;
   107 
   108 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
   109 now consider the syntactic context of assumptions, giving a better
   110 chance to get type-inference of the arguments right (this is
   111 especially important for locales);
   112 
   113 * Pure: "sorry" no longer requires quick_and_dirty in interactive
   114 mode;
   115 
   116 * Pure/obtain: the formal conclusion "thesis", being marked as
   117 ``internal'', may no longer be reference directly in the text;
   118 potential INCOMPATIBILITY, may need to use "?thesis" in rare
   119 situations;
   120 
   121 * Pure: generic 'sym' attribute which declares a rule both as pure
   122 'elim?' and for the 'symmetric' operation;
   123 
   124 * Pure/Provers/classical: simplified integration with pure rule
   125 attributes and methods; the classical "intro?/elim?/dest?"
   126 declarations coincide with the pure ones; the "rule" method no longer
   127 includes classically swapped intros; "intro" and "elim" methods no
   128 longer pick rules from the context; also got rid of ML declarations
   129 AddXIs/AddXEs/AddXDs; all of this has some potential for
   130 INCOMPATIBILITY;
   131 
   132 * Provers/classical: attribute 'swapped' produces classical inversions
   133 of introduction rules;
   134 
   135 * Provers/simplifier: 'simplified' attribute may refer to explicit
   136 rules instead of full simplifier context; 'iff' attribute handles
   137 conditional rules;
   138 
   139 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
   140 
   141 * HOL: 'recdef' now fails on unfinished automated proofs, use
   142 "(permissive)" option to recover old behavior;
   143 
   144 * HOL: 'inductive' no longer features separate (collective) attributes
   145 for 'intros' (was found too confusing);
   146 
   147 * HOL: properly declared induction rules less_induct and
   148 wf_induct_rule;
   149 
   150 
   151 *** HOL ***
   152 
   153 * HOL: moved over to sane numeral syntax; the new policy is as
   154 follows:
   155 
   156   - 0 and 1 are polymorphic constants, which are defined on any
   157   numeric type (nat, int, real etc.);
   158 
   159   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
   160   binary representation internally;
   161 
   162   - type nat has special constructor Suc, and generally prefers Suc 0
   163   over 1::nat and Suc (Suc 0) over 2::nat;
   164 
   165 This change may cause significant problems of INCOMPATIBILITY; here
   166 are some hints on converting existing sources:
   167 
   168   - due to the new "num" token, "-0" and "-1" etc. are now atomic
   169   entities, so expressions involving "-" (unary or binary minus) need
   170   to be spaced properly;
   171 
   172   - existing occurrences of "1" may need to be constraint "1::nat" or
   173   even replaced by Suc 0; similar for old "2";
   174 
   175   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
   176 
   177   - remove all special provisions on numerals in proofs;
   178 
   179 * HOL: the class of all HOL types is now called "type" rather than
   180 "term"; INCOMPATIBILITY, need to adapt references to this type class
   181 in axclass/classes, instance/arities, and (usually rare) occurrences
   182 in typings (of consts etc.); internally the class is called
   183 "HOL.type", ML programs should refer to HOLogic.typeS;
   184 
   185 * HOL/record package improvements:
   186   - new derived operations "fields" to build a partial record section,
   187     "extend" to promote a fixed record to a record scheme, and
   188     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
   189     declared as simp by default;
   190   - shared operations ("more", "fields", etc.) now need to be always
   191     qualified) --- potential INCOMPATIBILITY;
   192   - removed "make_scheme" operations (use "make" with "extend") --
   193     INCOMPATIBILITY;
   194   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
   195   - provides cases/induct rules for use with corresponding Isar
   196     methods (for concrete records, record schemes, concrete more
   197     parts, and schematic more parts -- in that order);
   198   - internal definitions directly based on a light-weight abstract
   199     theory of product types over typedef rather than datatype;
   200 
   201 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
   202 
   203 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
   204 (beware of argument permutation!);
   205 
   206 * HOL: linorder_less_split superseded by linorder_cases;
   207 
   208 * HOL: added "The" definite description operator; move Hilbert's "Eps"
   209 to peripheral theory "Hilbert_Choice";
   210 
   211 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
   212 in this (rare) case use:
   213 
   214   delSWrapper "split_all_tac"
   215   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
   216 
   217 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
   218 MAY FAIL;
   219 
   220 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
   221 Isabelle's type classes, ^ on functions and relations has too general
   222 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
   223 necessary to attach explicit type constraints;
   224 
   225 * HOL/Relation: the prefix name of the infix "O" has been changed from "comp"
   226 to "rel_comp"; INCOMPATIBILITY: a few theorems have been renamed accordingly
   227 (eg "compI" -> "rel_compI").
   228 
   229 * HOL: syntax translations now work properly with numerals and records
   230 expressions;
   231 
   232 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
   233 of "lam" -- INCOMPATIBILITY;
   234 
   235 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
   236 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
   237 renamed "Product_Type.unit";
   238 
   239 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
   240 
   241 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
   242 Florian Kammüller);
   243 
   244 * HOL/IMP: updated and converted to new-style theory format; several
   245 parts turned into readable document, with proper Isar proof texts and
   246 some explanations (by Gerwin Klein);
   247 
   248 * HOL-Hyperreal is now a logic image;
   249 
   250 
   251 *** HOLCF ***
   252 
   253 * Isar: consts/constdefs supports mixfix syntax for continuous
   254 operations;
   255 
   256 * Isar: domain package adapted to new-style theory format, e.g. see
   257 HOLCF/ex/Dnat.thy;
   258 
   259 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
   260 potential INCOMPATIBILITY; now use plain induct_tac instead of former
   261 lift.induct_tac, always use UU instead of Undef;
   262 
   263 * HOLCF/IMP: updated and converted to new-style theory;
   264 
   265 
   266 *** ZF ***
   267 
   268 * Isar: proper integration of logic-specific tools and packages,
   269 including theory commands '(co)inductive', '(co)datatype',
   270 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
   271 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
   272 
   273 * theory Main no longer includes AC; for the Axiom of Choice, base
   274 your theory on Main_ZFC;
   275 
   276 * the integer library now covers quotients and remainders, with many
   277 laws relating division to addition, multiplication, etc.;
   278 
   279 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
   280 typeless version of the formalism;
   281 
   282 * ZF/IMP: updated and converted to new-style theory format;
   283 
   284 * ZF/Induct: new directory for examples of inductive definitions,
   285 including theory Multiset for multiset orderings; converted to
   286 new-style theory format;
   287 
   288 
   289 *** General ***
   290 
   291 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
   292 variable proof controls level of detail: 0 = no proofs (only oracle
   293 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
   294 also ref manual for further ML interfaces;
   295 
   296 * Pure/axclass: removed obsolete ML interface
   297 goal_subclass/goal_arity;
   298 
   299 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
   300 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
   301 separate tokens, so expressions involving minus need to be spaced
   302 properly;
   303 
   304 * Pure/syntax: support non-oriented infixes, using keyword "infix"
   305 rather than "infixl" or "infixr";
   306 
   307 * Pure/syntax: concrete syntax for dummy type variables admits genuine
   308 sort constraint specifications in type inference; e.g. "x::_::foo"
   309 ensures that the type of "x" is of sort "foo" (but not necessarily a
   310 type variable);
   311 
   312 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
   313 control output of nested => (types); the default behavior is
   314 "type_brackets";
   315 
   316 * Pure/syntax: builtin parse translation for "_constify" turns valued
   317 tokens into AST constants;
   318 
   319 * Pure/syntax: prefer later declarations of translations and print
   320 translation functions; potential INCOMPATIBILITY: need to reverse
   321 multiple declarations for same syntax element constant;
   322 
   323 * Provers/classical: renamed addaltern to addafter, addSaltern to
   324 addSafter;
   325 
   326 * Provers/clasimp: ``iff'' declarations now handle conditional rules
   327 as well;
   328 
   329 * system: tested support for MacOS X; should be able to get Isabelle +
   330 Proof General to work in a plain Terminal after installing Poly/ML
   331 (e.g. from the Isabelle distribution area) and GNU bash alone
   332 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
   333 support requires further installations, e.g. from
   334 http://fink.sourceforge.net/);
   335 
   336 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
   337 
   338 * system: Proof General keywords specification is now part of the
   339 Isabelle distribution (see etc/isar-keywords.el);
   340 
   341 * system: some support for persistent Proof General sessions (refrain
   342 from outdating all loaded theories on startup);
   343 
   344 * system: smart selection of Isabelle process versus Isabelle
   345 interface, accommodates case-insensitive file systems (e.g. HFS+); may
   346 run both "isabelle" and "Isabelle" even if file names are badly
   347 damaged (executable inspects the case of the first letter of its own
   348 name); added separate "isabelle-process" and "isabelle-interface";
   349 
   350 * system: refrain from any attempt at filtering input streams; no
   351 longer support ``8bit'' encoding of old isabelle font, instead proper
   352 iso-latin characters may now be used; the related isatools
   353 "symbolinput" and "nonascii" have disappeared as well;
   354 
   355 * system: removed old "xterm" interface (the print modes "xterm" and
   356 "xterm_color" are still available for direct use in a suitable
   357 terminal);
   358 
   359 
   360 
   361 New in Isabelle99-2 (February 2001)
   362 -----------------------------------
   363 
   364 *** Overview of INCOMPATIBILITIES ***
   365 
   366 * HOL: please note that theories in the Library and elsewhere often use the
   367 new-style (Isar) format; to refer to their theorems in an ML script you must
   368 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
   369 
   370 * HOL: inductive package no longer splits induction rule aggressively,
   371 but only as far as specified by the introductions given; the old
   372 format may be recovered via ML function complete_split_rule or attribute
   373 'split_rule (complete)';
   374 
   375 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
   376 gfp_Tarski to gfp_unfold;
   377 
   378 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
   379 
   380 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
   381 relation); infix "^^" has been renamed "``"; infix "``" has been
   382 renamed "`"; "univalent" has been renamed "single_valued";
   383 
   384 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
   385 operation;
   386 
   387 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
   388 
   389 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
   390 
   391 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
   392 consequence, it is no longer monotonic wrt. the local goal context
   393 (which is now passed through the inductive cases);
   394 
   395 * Document preparation: renamed standard symbols \<ll> to \<lless> and
   396 \<gg> to \<ggreater>;
   397 
   398 
   399 *** Document preparation ***
   400 
   401 * \isabellestyle{NAME} selects version of Isabelle output (currently
   402 available: are "it" for near math-mode best-style output, "sl" for
   403 slanted text style, and "tt" for plain type-writer; if no
   404 \isabellestyle command is given, output is according to slanted
   405 type-writer);
   406 
   407 * support sub/super scripts (for single symbols only), input syntax is
   408 like this: "A\<^sup>*" or "A\<^sup>\<star>";
   409 
   410 * some more standard symbols; see Appendix A of the system manual for
   411 the complete list of symbols defined in isabellesym.sty;
   412 
   413 * improved isabelle style files; more abstract symbol implementation
   414 (should now use \isamath{...} and \isatext{...} in custom symbol
   415 definitions);
   416 
   417 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
   418 state; Note that presentation of goal states does not conform to
   419 actual human-readable proof documents.  Please do not include goal
   420 states into document output unless you really know what you are doing!
   421 
   422 * proper indentation of antiquoted output with proportional LaTeX
   423 fonts;
   424 
   425 * no_document ML operator temporarily disables LaTeX document
   426 generation;
   427 
   428 * isatool unsymbolize tunes sources for plain ASCII communication;
   429 
   430 
   431 *** Isar ***
   432 
   433 * Pure: Isar now suffers initial goal statements to contain unbound
   434 schematic variables (this does not conform to actual readable proof
   435 documents, due to unpredictable outcome and non-compositional proof
   436 checking); users who know what they are doing may use schematic goals
   437 for Prolog-style synthesis of proven results;
   438 
   439 * Pure: assumption method (an implicit finishing) now handles actual
   440 rules as well;
   441 
   442 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
   443 initial goal, declare "that" only as Pure intro (only for single
   444 steps); the "that" rule assumption may now be involved in implicit
   445 finishing, thus ".." becomes a feasible for trivial obtains;
   446 
   447 * Pure: default proof step now includes 'intro_classes'; thus trivial
   448 instance proofs may be performed by "..";
   449 
   450 * Pure: ?thesis / ?this / "..." now work for pure meta-level
   451 statements as well;
   452 
   453 * Pure: more robust selection of calculational rules;
   454 
   455 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
   456 rule (as well as the assumption rule);
   457 
   458 * Pure: 'thm_deps' command visualizes dependencies of theorems and
   459 lemmas, using the graph browser tool;
   460 
   461 * Pure: predict failure of "show" in interactive mode;
   462 
   463 * Pure: 'thms_containing' now takes actual terms as arguments;
   464 
   465 * HOL: improved method 'induct' --- now handles non-atomic goals
   466 (potential INCOMPATIBILITY); tuned error handling;
   467 
   468 * HOL: cases and induct rules now provide explicit hints about the
   469 number of facts to be consumed (0 for "type" and 1 for "set" rules);
   470 any remaining facts are inserted into the goal verbatim;
   471 
   472 * HOL: local contexts (aka cases) may now contain term bindings as
   473 well; the 'cases' and 'induct' methods new provide a ?case binding for
   474 the result to be shown in each case;
   475 
   476 * HOL: added 'recdef_tc' command;
   477 
   478 * isatool convert assists in eliminating legacy ML scripts;
   479 
   480 
   481 *** HOL ***
   482 
   483 * HOL/Library: a collection of generic theories to be used together
   484 with main HOL; the theory loader path already includes this directory
   485 by default; the following existing theories have been moved here:
   486 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
   487 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
   488 
   489 * HOL/Unix: "Some aspects of Unix file-system security", a typical
   490 modelling and verification task performed in Isabelle/HOL +
   491 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
   492 
   493 * HOL/Algebra: special summation operator SUM no longer exists, it has
   494 been replaced by setsum; infix 'assoc' now has priority 50 (like
   495 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
   496 'domain', this makes the theory consistent with mathematical
   497 literature;
   498 
   499 * HOL basics: added overloaded operations "inverse" and "divide"
   500 (infix "/"), syntax for generic "abs" operation, generic summation
   501 operator \<Sum>;
   502 
   503 * HOL/typedef: simplified package, provide more useful rules (see also
   504 HOL/subset.thy);
   505 
   506 * HOL/datatype: induction rule for arbitrarily branching datatypes is
   507 now expressed as a proper nested rule (old-style tactic scripts may
   508 require atomize_strip_tac to cope with non-atomic premises);
   509 
   510 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
   511 to "split_conv" (old name still available for compatibility);
   512 
   513 * HOL: improved concrete syntax for strings (e.g. allows translation
   514 rules with string literals);
   515 
   516 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
   517  and Fleuriot's mechanization of analysis, including the transcendental
   518  functions for the reals;
   519 
   520 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
   521 
   522 
   523 *** CTT ***
   524 
   525 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
   526 "lam" is displayed as TWO lambda-symbols
   527 
   528 * CTT: theory Main now available, containing everything (that is, Bool
   529 and Arith);
   530 
   531 
   532 *** General ***
   533 
   534 * Pure: the Simplifier has been implemented properly as a derived rule
   535 outside of the actual kernel (at last!); the overall performance
   536 penalty in practical applications is about 50%, while reliability of
   537 the Isabelle inference kernel has been greatly improved;
   538 
   539 * print modes "brackets" and "no_brackets" control output of nested =>
   540 (types) and ==> (props); the default behaviour is "brackets";
   541 
   542 * Provers: fast_tac (and friends) now handle actual object-logic rules
   543 as assumptions as well;
   544 
   545 * system: support Poly/ML 4.0;
   546 
   547 * system: isatool install handles KDE version 1 or 2;
   548 
   549 
   550 
   551 New in Isabelle99-1 (October 2000)
   552 ----------------------------------
   553 
   554 *** Overview of INCOMPATIBILITIES ***
   555 
   556 * HOL: simplification of natural numbers is much changed; to partly
   557 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
   558 issue the following ML commands:
   559 
   560   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
   561   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
   562 
   563 * HOL: simplification no longer dives into case-expressions; this is
   564 controlled by "t.weak_case_cong" for each datatype t;
   565 
   566 * HOL: nat_less_induct renamed to less_induct;
   567 
   568 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
   569 fixsome to patch .thy and .ML sources automatically;
   570 
   571   select_equality  -> some_equality
   572   select_eq_Ex     -> some_eq_ex
   573   selectI2EX       -> someI2_ex
   574   selectI2         -> someI2
   575   selectI          -> someI
   576   select1_equality -> some1_equality
   577   Eps_sym_eq       -> some_sym_eq_trivial
   578   Eps_eq           -> some_eq_trivial
   579 
   580 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
   581 
   582 * HOL: removed obsolete theorem binding expand_if (refer to split_if
   583 instead);
   584 
   585 * HOL: the recursion equations generated by 'recdef' are now called
   586 f.simps instead of f.rules;
   587 
   588 * HOL: qed_spec_mp now also handles bounded ALL as well;
   589 
   590 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
   591 sometimes be needed;
   592 
   593 * HOL: the constant for "f``x" is now "image" rather than "op ``";
   594 
   595 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
   596 
   597 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
   598 product is now "<*>" instead of "Times"; the lexicographic product is
   599 now "<*lex*>" instead of "**";
   600 
   601 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
   602 of main HOL, but was unused); better use HOL's datatype package;
   603 
   604 * HOL: removed "symbols" syntax for constant "override" of theory Map;
   605 the old syntax may be recovered as follows:
   606 
   607   syntax (symbols)
   608     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
   609       (infixl "\\<oplus>" 100)
   610 
   611 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   612 
   613 * HOL/ML: even fewer consts are declared as global (see theories Ord,
   614 Lfp, Gfp, WF); this only affects ML packages that refer to const names
   615 internally;
   616 
   617 * HOL and ZF: syntax for quotienting wrt an equivalence relation
   618 changed from A/r to A//r;
   619 
   620 * ZF: new treatment of arithmetic (nat & int) may break some old
   621 proofs;
   622 
   623 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
   624 rulify -> rule_format, elimify -> elim_format, ...);
   625 
   626 * Isar/Provers: intro/elim/dest attributes changed; renamed
   627 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
   628 should have to change intro!! to intro? only); replaced "delrule" by
   629 "rule del";
   630 
   631 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
   632 
   633 * Provers: strengthened force_tac by using new first_best_tac;
   634 
   635 * LaTeX document preparation: several changes of isabelle.sty (see
   636 lib/texinputs);
   637 
   638 
   639 *** Document preparation ***
   640 
   641 * formal comments (text blocks etc.) in new-style theories may now
   642 contain antiquotations of thm/prop/term/typ/text to be presented
   643 according to latex print mode; concrete syntax is like this:
   644 @{term[show_types] "f(x) = a + x"};
   645 
   646 * isatool mkdir provides easy setup of Isabelle session directories,
   647 including proper document sources;
   648 
   649 * generated LaTeX sources are now deleted after successful run
   650 (isatool document -c); may retain a copy somewhere else via -D option
   651 of isatool usedir;
   652 
   653 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
   654 style files, achieving self-contained LaTeX sources and simplifying
   655 LaTeX debugging;
   656 
   657 * old-style theories now produce (crude) LaTeX output as well;
   658 
   659 * browser info session directories are now self-contained (may be put
   660 on WWW server seperately); improved graphs of nested sessions; removed
   661 graph for 'all sessions';
   662 
   663 * several improvements in isabelle style files; \isabellestyle{it}
   664 produces fake math mode output; \isamarkupheader is now \section by
   665 default; see lib/texinputs/isabelle.sty etc.;
   666 
   667 
   668 *** Isar ***
   669 
   670 * Isar/Pure: local results and corresponding term bindings are now
   671 subject to Hindley-Milner polymorphism (similar to ML); this
   672 accommodates incremental type-inference very nicely;
   673 
   674 * Isar/Pure: new derived language element 'obtain' supports
   675 generalized existence reasoning;
   676 
   677 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
   678 support accumulation of results, without applying any rules yet;
   679 useful to collect intermediate results without explicit name
   680 references, and for use with transitivity rules with more than 2
   681 premises;
   682 
   683 * Isar/Pure: scalable support for case-analysis type proofs: new
   684 'case' language element refers to local contexts symbolically, as
   685 produced by certain proof methods; internally, case names are attached
   686 to theorems as "tags";
   687 
   688 * Isar/Pure: theory command 'hide' removes declarations from
   689 class/type/const name spaces;
   690 
   691 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
   692 indicate potential overloading;
   693 
   694 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
   695 
   696 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
   697 "{a,b,c}" instead of {a,b,c};
   698 
   699 * Isar/Pure now provides its own version of intro/elim/dest
   700 attributes; useful for building new logics, but beware of confusion
   701 with the version in Provers/classical;
   702 
   703 * Isar/Pure: the local context of (non-atomic) goals is provided via
   704 case name 'antecedent';
   705 
   706 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
   707 to the current context is now done automatically);
   708 
   709 * Isar/Pure: theory command 'method_setup' provides a simple interface
   710 for definining proof methods in ML;
   711 
   712 * Isar/Provers: intro/elim/dest attributes changed; renamed
   713 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
   714 most cases, one should have to change intro!! to intro? only);
   715 replaced "delrule" by "rule del";
   716 
   717 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
   718 'symmetric' attribute (the latter supercedes [RS sym]);
   719 
   720 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
   721 method modifier); 'simp' method: 'only:' modifier removes loopers as
   722 well (including splits);
   723 
   724 * Isar/Provers: Simplifier and Classical methods now support all kind
   725 of modifiers used in the past, including 'cong', 'iff', etc.
   726 
   727 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
   728 of Simplifier and Classical reasoner);
   729 
   730 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
   731 now support named cases; major packages (inductive, datatype, primrec,
   732 recdef) support case names and properly name parameters;
   733 
   734 * Isar/HOL: new transitivity rules for substitution in inequalities --
   735 monotonicity conditions are extracted to be proven at end of
   736 calculations;
   737 
   738 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
   739 method anyway;
   740 
   741 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
   742 split_if split_if_asm; datatype package provides theorems foo.splits =
   743 foo.split foo.split_asm for each datatype;
   744 
   745 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
   746 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
   747 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
   748 use "(cases (simplified))" method in proper proof texts);
   749 
   750 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
   751 
   752 * Isar: names of theorems etc. may be natural numbers as well;
   753 
   754 * Isar: 'pr' command: optional arguments for goals_limit and
   755 ProofContext.prems_limit; no longer prints theory contexts, but only
   756 proof states;
   757 
   758 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
   759 additional print modes to be specified; e.g. "pr(latex)" will print
   760 proof state according to the Isabelle LaTeX style;
   761 
   762 * Isar: improved support for emulating tactic scripts, including proof
   763 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
   764 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
   765 (for HOL datatypes);
   766 
   767 * Isar: simplified (more robust) goal selection of proof methods: 1st
   768 goal, all goals, or explicit goal specifier (tactic emulation); thus
   769 'proof method scripts' have to be in depth-first order;
   770 
   771 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
   772 
   773 * Isar: removed 'help' command, which hasn't been too helpful anyway;
   774 should instead use individual commands for printing items
   775 (print_commands, print_methods etc.);
   776 
   777 * Isar: added 'nothing' --- the empty list of theorems;
   778 
   779 
   780 *** HOL ***
   781 
   782 * HOL/MicroJava: formalization of a fragment of Java, together with a
   783 corresponding virtual machine and a specification of its bytecode
   784 verifier and a lightweight bytecode verifier, including proofs of
   785 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
   786 Cornelia Pusch (see also the homepage of project Bali at
   787 http://isabelle.in.tum.de/Bali/);
   788 
   789 * HOL/Algebra: new theory of rings and univariate polynomials, by
   790 Clemens Ballarin;
   791 
   792 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
   793 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
   794 Rasmussen;
   795 
   796 * HOL/Lattice: fundamental concepts of lattice theory and order
   797 structures, including duals, properties of bounds versus algebraic
   798 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
   799 Theorem for complete lattices etc.; may also serve as a demonstration
   800 for abstract algebraic reasoning using axiomatic type classes, and
   801 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
   802 
   803 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
   804 von Oheimb;
   805 
   806 * HOL/IMPP: extension of IMP with local variables and mutually
   807 recursive procedures, by David von Oheimb;
   808 
   809 * HOL/Lambda: converted into new-style theory and document;
   810 
   811 * HOL/ex/Multiquote: example of multiple nested quotations and
   812 anti-quotations -- basically a generalized version of de-Bruijn
   813 representation; very useful in avoiding lifting of operations;
   814 
   815 * HOL/record: added general record equality rule to simpset; fixed
   816 select-update simplification procedure to handle extended records as
   817 well; admit "r" as field name;
   818 
   819 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
   820 other numeric types and also as the identity of groups, rings, etc.;
   821 
   822 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
   823 Types nat and int belong to this axclass;
   824 
   825 * HOL: greatly improved simplification involving numerals of type nat, int, real:
   826    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
   827    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
   828   two terms #m*u and #n*u are replaced by #(m+n)*u
   829     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
   830   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
   831     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
   832 
   833 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
   834 powerful prover for predicate logic but knows nothing of clasets; see
   835 ex/mesontest.ML and ex/mesontest2.ML for example applications;
   836 
   837 * HOL: new version of "case_tac" subsumes both boolean case split and
   838 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
   839 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
   840 
   841 * HOL: simplification no longer dives into case-expressions: only the
   842 selector expression is simplified, but not the remaining arms; to
   843 enable full simplification of case-expressions for datatype t, you may
   844 remove t.weak_case_cong from the simpset, either globally (Delcongs
   845 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
   846 
   847 * HOL/recdef: the recursion equations generated by 'recdef' for
   848 function 'f' are now called f.simps instead of f.rules; if all
   849 termination conditions are proved automatically, these simplification
   850 rules are added to the simpset, as in primrec; rules may be named
   851 individually as well, resulting in a separate list of theorems for
   852 each equation;
   853 
   854 * HOL/While is a new theory that provides a while-combinator. It
   855 permits the definition of tail-recursive functions without the
   856 provision of a termination measure. The latter is necessary once the
   857 invariant proof rule for while is applied.
   858 
   859 * HOL: new (overloaded) notation for the set of elements below/above
   860 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
   861 
   862 * HOL: theorems impI, allI, ballI bound as "strip";
   863 
   864 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
   865 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
   866 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
   867 
   868 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   869 
   870 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
   871 main HOL, but was unused);
   872 
   873 * HOL: fewer consts declared as global (e.g. have to refer to
   874 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
   875 
   876 * HOL: tuned AST representation of nested pairs, avoiding bogus output
   877 in case of overlap with user translations (e.g. judgements over
   878 tuples); (note that the underlying logical represenation is still
   879 bogus);
   880 
   881 
   882 *** ZF ***
   883 
   884 * ZF: simplification automatically cancels common terms in arithmetic
   885 expressions over nat and int;
   886 
   887 * ZF: new treatment of nat to minimize type-checking: all operators
   888 coerce their operands to a natural number using the function natify,
   889 making the algebraic laws unconditional;
   890 
   891 * ZF: as above, for int: operators coerce their operands to an integer
   892 using the function intify;
   893 
   894 * ZF: the integer library now contains many of the usual laws for the
   895 orderings, including $<=, and monotonicity laws for $+ and $*;
   896 
   897 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
   898 simplification;
   899 
   900 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
   901 to the simplifier and classical reasoner simultaneously;
   902 
   903 
   904 *** General ***
   905 
   906 * Provers: blast_tac now handles actual object-logic rules as
   907 assumptions; note that auto_tac uses blast_tac internally as well;
   908 
   909 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
   910 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
   911 
   912 * Provers: delrules now handles destruct rules as well (no longer need
   913 explicit make_elim);
   914 
   915 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
   916   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   917 use instead the strong form,
   918   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   919 in HOL, FOL and ZF the function cla_make_elim will create such rules
   920 from destruct-rules;
   921 
   922 * Provers: Simplifier.easy_setup provides a fast path to basic
   923 Simplifier setup for new object-logics;
   924 
   925 * Pure: AST translation rules no longer require constant head on LHS;
   926 
   927 * Pure: improved name spaces: ambiguous output is qualified; support
   928 for hiding of names;
   929 
   930 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
   931 XSYMBOL_HOME; no longer need to do manual configuration in most
   932 situations;
   933 
   934 * system: compression of ML heaps images may now be controlled via -c
   935 option of isabelle and isatool usedir (currently only observed by
   936 Poly/ML);
   937 
   938 * system: isatool installfonts may handle X-Symbol fonts as well (very
   939 useful for remote X11);
   940 
   941 * system: provide TAGS file for Isabelle sources;
   942 
   943 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
   944 order;
   945 
   946 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
   947 timing flag supersedes proof_timing and Toplevel.trace;
   948 
   949 * ML: new combinators |>> and |>>> for incremental transformations
   950 with secondary results (e.g. certain theory extensions):
   951 
   952 * ML: PureThy.add_defs gets additional argument to indicate potential
   953 overloading (usually false);
   954 
   955 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
   956 results;
   957 
   958 
   959 
   960 New in Isabelle99 (October 1999)
   961 --------------------------------
   962 
   963 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   964 
   965 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
   966 are no longer simplified.  (This allows the simplifier to unfold recursive
   967 functional programs.)  To restore the old behaviour, declare
   968 
   969     Delcongs [if_weak_cong];
   970 
   971 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
   972 complement;
   973 
   974 * HOL: the predicate "inj" is now defined by translation to "inj_on";
   975 
   976 * HOL/datatype: mutual_induct_tac no longer exists --
   977   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
   978 
   979 * HOL/typedef: fixed type inference for representing set; type
   980 arguments now have to occur explicitly on the rhs as type constraints;
   981 
   982 * ZF: The con_defs part of an inductive definition may no longer refer
   983 to constants declared in the same theory;
   984 
   985 * HOL, ZF: the function mk_cases, generated by the inductive
   986 definition package, has lost an argument.  To simplify its result, it
   987 uses the default simpset instead of a supplied list of theorems.
   988 
   989 * HOL/List: the constructors of type list are now Nil and Cons;
   990 
   991 * Simplifier: the type of the infix ML functions
   992         setSSolver addSSolver setSolver addSolver
   993 is now  simpset * solver -> simpset  where `solver' is a new abstract type
   994 for packaging solvers. A solver is created via
   995         mk_solver: string -> (thm list -> int -> tactic) -> solver
   996 where the string argument is only a comment.
   997 
   998 
   999 *** Proof tools ***
  1000 
  1001 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  1002 decision procedure for linear arithmetic. Currently it is used for
  1003 types `nat', `int', and `real' in HOL (see below); it can, should and
  1004 will be instantiated for other types and logics as well.
  1005 
  1006 * The simplifier now accepts rewrite rules with flexible heads, eg
  1007      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  1008   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  1009   matching.
  1010 
  1011 
  1012 *** General ***
  1013 
  1014 * New Isabelle/Isar subsystem provides an alternative to traditional
  1015 tactical theorem proving; together with the ProofGeneral/isar user
  1016 interface it offers an interactive environment for developing human
  1017 readable proof documents (Isar == Intelligible semi-automated
  1018 reasoning); for further information see isatool doc isar-ref,
  1019 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  1020 
  1021 * improved and simplified presentation of theories: better HTML markup
  1022 (including colors), graph views in several sizes; isatool usedir now
  1023 provides a proper interface for user theories (via -P option); actual
  1024 document preparation based on (PDF)LaTeX is available as well (for
  1025 new-style theories only); see isatool doc system for more information;
  1026 
  1027 * native support for Proof General, both for classic Isabelle and
  1028 Isabelle/Isar;
  1029 
  1030 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  1031 using the graph browser tool;
  1032 
  1033 * Isabelle manuals now also available as PDF;
  1034 
  1035 * theory loader rewritten from scratch (may not be fully
  1036 bug-compatible); old loadpath variable has been replaced by show_path,
  1037 add_path, del_path, reset_path functions; new operations such as
  1038 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  1039 isatool doc ref);
  1040 
  1041 * improved isatool install: option -k creates KDE application icon,
  1042 option -p DIR installs standalone binaries;
  1043 
  1044 * added ML_PLATFORM setting (useful for cross-platform installations);
  1045 more robust handling of platform specific ML images for SML/NJ;
  1046 
  1047 * the settings environment is now statically scoped, i.e. it is never
  1048 created again in sub-processes invoked from isabelle, isatool, or
  1049 Isabelle;
  1050 
  1051 * path element specification '~~' refers to '$ISABELLE_HOME';
  1052 
  1053 * in locales, the "assumes" and "defines" parts may be omitted if
  1054 empty;
  1055 
  1056 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  1057 long arrows);
  1058 
  1059 * new print_mode "HTML";
  1060 
  1061 * new flag show_tags controls display of tags of theorems (which are
  1062 basically just comments that may be attached by some tools);
  1063 
  1064 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  1065 mode and goal output format:
  1066 
  1067 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  1068 244c244
  1069 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  1070 ---
  1071 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  1072 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  1073 181c181
  1074 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  1075 ---
  1076 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  1077 
  1078 * function bind_thms stores lists of theorems (cf. bind_thm);
  1079 
  1080 * new shorthand tactics ftac, eatac, datac, fatac;
  1081 
  1082 * qed (and friends) now accept "" as result name; in that case the
  1083 theorem is not stored, but proper checks and presentation of the
  1084 result still apply;
  1085 
  1086 * theorem database now also indexes constants "Trueprop", "all",
  1087 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  1088 
  1089 
  1090 *** HOL ***
  1091 
  1092 ** HOL arithmetic **
  1093 
  1094 * There are now decision procedures for linear arithmetic over nat and
  1095 int:
  1096 
  1097 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  1098 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  1099 are treated as atomic; subformulae not involving type `nat' or `int'
  1100 are ignored; quantified subformulae are ignored unless they are
  1101 positive universal or negative existential. The tactic has to be
  1102 invoked by hand and can be a little bit slow. In particular, the
  1103 running time is exponential in the number of occurrences of `min' and
  1104 `max', and `-' on `nat'.
  1105 
  1106 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  1107 (negated) (in)equalities among the premises and the conclusion into
  1108 account (i.e. no compound formulae) and does not know about `min' and
  1109 `max', and `-' on `nat'. It is fast and is used automatically by the
  1110 simplifier.
  1111 
  1112 NB: At the moment, these decision procedures do not cope with mixed
  1113 nat/int formulae where the two parts interact, such as `m < n ==>
  1114 int(m) < int(n)'.
  1115 
  1116 * HOL/Numeral provides a generic theory of numerals (encoded
  1117 efficiently as bit strings); setup for types nat/int/real is in place;
  1118 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  1119 int, existing theories and proof scripts may require a few additional
  1120 type constraints;
  1121 
  1122 * integer division and remainder can now be performed on constant
  1123 arguments;
  1124 
  1125 * many properties of integer multiplication, division and remainder
  1126 are now available;
  1127 
  1128 * An interface to the Stanford Validity Checker (SVC) is available through the
  1129 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  1130 are proved automatically.  SVC must be installed separately, and its results
  1131 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  1132 invocation of the underlying oracle).  For SVC see
  1133   http://verify.stanford.edu/SVC
  1134 
  1135 * IsaMakefile: the HOL-Real target now builds an actual image;
  1136 
  1137 
  1138 ** HOL misc **
  1139 
  1140 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  1141 (in Isabelle/Isar) -- by Gertrud Bauer;
  1142 
  1143 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  1144 analysis for assembly languages with subtypes;
  1145 
  1146 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  1147 -- avoids syntactic ambiguities and treats state, transition, and
  1148 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  1149 changed syntax and (many) tactics;
  1150 
  1151 * HOL/inductive: Now also handles more general introduction rules such
  1152   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  1153   theorems are now maintained within the theory (maintained via the
  1154   "mono" attribute);
  1155 
  1156 * HOL/datatype: Now also handles arbitrarily branching datatypes
  1157   (using function types) such as
  1158 
  1159   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  1160 
  1161 * HOL/record: record_simproc (part of the default simpset) takes care
  1162 of selectors applied to updated records; record_split_tac is no longer
  1163 part of the default claset; update_defs may now be removed from the
  1164 simpset in many cases; COMPATIBILITY: old behavior achieved by
  1165 
  1166   claset_ref () := claset() addSWrapper record_split_wrapper;
  1167   Delsimprocs [record_simproc]
  1168 
  1169 * HOL/typedef: fixed type inference for representing set; type
  1170 arguments now have to occur explicitly on the rhs as type constraints;
  1171 
  1172 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  1173 names rather than an ML expression;
  1174 
  1175 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  1176 supplied later.  Program schemes can be defined, such as
  1177     "While B C s = (if B s then While B C (C s) else s)"
  1178 where the well-founded relation can be chosen after B and C have been given.
  1179 
  1180 * HOL/List: the constructors of type list are now Nil and Cons;
  1181 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  1182 course, ML tools referring to List.list.op # etc. have to be adapted;
  1183 
  1184 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  1185 disabled by default; run isabelle with option -m HOL to get back to
  1186 the original Gordon/HOL-style output;
  1187 
  1188 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  1189 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  1190 
  1191 * HOL basic syntax simplified (more orthogonal): all variants of
  1192 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  1193 Eps operator is provided as well: "SOME x. P[x]";
  1194 
  1195 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  1196 
  1197 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  1198 thus available for user theories;
  1199 
  1200 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  1201 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  1202 time;
  1203 
  1204 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  1205 several times and then mp;
  1206 
  1207 
  1208 *** LK ***
  1209 
  1210 * the notation <<...>> is now available as a notation for sequences of
  1211 formulas;
  1212 
  1213 * the simplifier is now installed
  1214 
  1215 * the axiom system has been generalized (thanks to Soren Heilmann)
  1216 
  1217 * the classical reasoner now has a default rule database
  1218 
  1219 
  1220 *** ZF ***
  1221 
  1222 * new primrec section allows primitive recursive functions to be given
  1223 directly (as in HOL) over datatypes and the natural numbers;
  1224 
  1225 * new tactics induct_tac and exhaust_tac for induction (or case
  1226 analysis) over datatypes and the natural numbers;
  1227 
  1228 * the datatype declaration of type T now defines the recursor T_rec;
  1229 
  1230 * simplification automatically does freeness reasoning for datatype
  1231 constructors;
  1232 
  1233 * automatic type-inference, with AddTCs command to insert new
  1234 type-checking rules;
  1235 
  1236 * datatype introduction rules are now added as Safe Introduction rules
  1237 to the claset;
  1238 
  1239 * the syntax "if P then x else y" is now available in addition to
  1240 if(P,x,y);
  1241 
  1242 
  1243 *** Internal programming interfaces ***
  1244 
  1245 * tuned simplifier trace output; new flag debug_simp;
  1246 
  1247 * structures Vartab / Termtab (instances of TableFun) offer efficient
  1248 tables indexed by indexname_ord / term_ord (compatible with aconv);
  1249 
  1250 * AxClass.axclass_tac lost the theory argument;
  1251 
  1252 * tuned current_goals_markers semantics: begin / end goal avoids
  1253 printing empty lines;
  1254 
  1255 * removed prs and prs_fn hook, which was broken because it did not
  1256 include \n in its semantics, forcing writeln to add one
  1257 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  1258 string -> unit if you really want to output text without newline;
  1259 
  1260 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  1261 plain output, interface builders may have to enable 'isabelle_font'
  1262 mode to get Isabelle font glyphs as before;
  1263 
  1264 * refined token_translation interface; INCOMPATIBILITY: output length
  1265 now of type real instead of int;
  1266 
  1267 * theory loader actions may be traced via new ThyInfo.add_hook
  1268 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  1269 your own database of information attached to *whole* theories -- as
  1270 opposed to intra-theory data slots offered via TheoryDataFun;
  1271 
  1272 * proper handling of dangling sort hypotheses (at last!);
  1273 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  1274 extra sort hypotheses that can be witnessed from the type signature;
  1275 the force_strip_shyps flag is gone, any remaining shyps are simply
  1276 left in the theorem (with a warning issued by strip_shyps_warning);
  1277 
  1278 
  1279 
  1280 New in Isabelle98-1 (October 1998)
  1281 ----------------------------------
  1282 
  1283 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1284 
  1285 * several changes of automated proof tools;
  1286 
  1287 * HOL: major changes to the inductive and datatype packages, including
  1288 some minor incompatibilities of theory syntax;
  1289 
  1290 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  1291 called `inj_on';
  1292 
  1293 * HOL: removed duplicate thms in Arith:
  1294   less_imp_add_less  should be replaced by  trans_less_add1
  1295   le_imp_add_le      should be replaced by  trans_le_add1
  1296 
  1297 * HOL: unary minus is now overloaded (new type constraints may be
  1298 required);
  1299 
  1300 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  1301 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  1302 now taken as an integer constant.
  1303 
  1304 * Pure: ML function 'theory_of' renamed to 'theory';
  1305 
  1306 
  1307 *** Proof tools ***
  1308 
  1309 * Simplifier:
  1310   1. Asm_full_simp_tac is now more aggressive.
  1311      1. It will sometimes reorient premises if that increases their power to
  1312         simplify.
  1313      2. It does no longer proceed strictly from left to right but may also
  1314         rotate premises to achieve further simplification.
  1315      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  1316      old Asm_full_simp_tac in that it does not rotate premises.
  1317   2. The simplifier now knows a little bit about nat-arithmetic.
  1318 
  1319 * Classical reasoner: wrapper mechanism for the classical reasoner now
  1320 allows for selected deletion of wrappers, by introduction of names for
  1321 wrapper functionals.  This implies that addbefore, addSbefore,
  1322 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  1323 and that adding two tactics with the same name overwrites the first
  1324 one (emitting a warning).
  1325   type wrapper = (int -> tactic) -> (int -> tactic)
  1326   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  1327   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  1328   delWrapper, delSWrapper: claset *  string            -> claset
  1329   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  1330 
  1331 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  1332 semantics; addbefore now affects only the unsafe part of step_tac
  1333 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  1334 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  1335 by Force_tac;
  1336 
  1337 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  1338 compWrapper; added safe wrapper (and access functions for it);
  1339 
  1340 * HOL/split_all_tac is now much faster and fails if there is nothing
  1341 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  1342 and the names of the automatically generated variables have changed.
  1343 split_all_tac has moved within claset() from unsafe wrappers to safe
  1344 wrappers, which means that !!-bound variables are split much more
  1345 aggressively, and safe_tac and clarify_tac now split such variables.
  1346 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  1347 Note: the same holds for record_split_tac, which does the job of
  1348 split_all_tac for record fields.
  1349 
  1350 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  1351 permanently to the default simpset using Addsplits just like
  1352 Addsimps. They can be removed via Delsplits just like
  1353 Delsimps. Lower-case versions are also available.
  1354 
  1355 * HOL/Simplifier: The rule split_if is now part of the default
  1356 simpset. This means that the simplifier will eliminate all occurrences
  1357 of if-then-else in the conclusion of a goal. To prevent this, you can
  1358 either remove split_if completely from the default simpset by
  1359 `Delsplits [split_if]' or remove it in a specific call of the
  1360 simplifier using `... delsplits [split_if]'.  You can also add/delete
  1361 other case splitting rules to/from the default simpset: every datatype
  1362 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  1363 t is the name of the datatype).
  1364 
  1365 * Classical reasoner / Simplifier combination: new force_tac (and
  1366 derivatives Force_tac, force) combines rewriting and classical
  1367 reasoning (and whatever other tools) similarly to auto_tac, but is
  1368 aimed to solve the given subgoal completely.
  1369 
  1370 
  1371 *** General ***
  1372 
  1373 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  1374 and `goalw': the theory is no longer needed as an explicit argument -
  1375 the current theory context is used; assumptions are no longer returned
  1376 at the ML-level unless one of them starts with ==> or !!; it is
  1377 recommended to convert to these new commands using isatool fixgoal
  1378 (backup your sources first!);
  1379 
  1380 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  1381 the current theory context, and 'theory' to lookup stored theories;
  1382 
  1383 * new theory section 'locale' for declaring constants, assumptions and
  1384 definitions that have local scope;
  1385 
  1386 * new theory section 'nonterminals' for purely syntactic types;
  1387 
  1388 * new theory section 'setup' for generic ML setup functions
  1389 (e.g. package initialization);
  1390 
  1391 * the distribution now includes Isabelle icons: see
  1392 lib/logo/isabelle-{small,tiny}.xpm;
  1393 
  1394 * isatool install - install binaries with absolute references to
  1395 ISABELLE_HOME/bin;
  1396 
  1397 * isatool logo -- create instances of the Isabelle logo (as EPS);
  1398 
  1399 * print mode 'emacs' reserved for Isamode;
  1400 
  1401 * support multiple print (ast) translations per constant name;
  1402 
  1403 * theorems involving oracles are now printed with a suffixed [!];
  1404 
  1405 
  1406 *** HOL ***
  1407 
  1408 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  1409 
  1410 * HOL/inductive package reorganized and improved: now supports mutual
  1411 definitions such as
  1412 
  1413   inductive EVEN ODD
  1414     intrs
  1415       null "0 : EVEN"
  1416       oddI "n : EVEN ==> Suc n : ODD"
  1417       evenI "n : ODD ==> Suc n : EVEN"
  1418 
  1419 new theorem list "elims" contains an elimination rule for each of the
  1420 recursive sets; inductive definitions now handle disjunctive premises
  1421 correctly (also ZF);
  1422 
  1423 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  1424 "mutual_induct" no longer exists - the induction rule is always
  1425 contained in "induct";
  1426 
  1427 
  1428 * HOL/datatype package re-implemented and greatly improved: now
  1429 supports mutually recursive datatypes such as
  1430 
  1431   datatype
  1432     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  1433             | SUM ('a aexp) ('a aexp)
  1434             | DIFF ('a aexp) ('a aexp)
  1435             | NUM 'a
  1436   and
  1437     'a bexp = LESS ('a aexp) ('a aexp)
  1438             | AND ('a bexp) ('a bexp)
  1439             | OR ('a bexp) ('a bexp)
  1440 
  1441 as well as indirectly recursive datatypes such as
  1442 
  1443   datatype
  1444     ('a, 'b) term = Var 'a
  1445                   | App 'b ((('a, 'b) term) list)
  1446 
  1447 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  1448 induction on mutually / indirectly recursive datatypes.
  1449 
  1450 Primrec equations are now stored in theory and can be accessed via
  1451 <function_name>.simps.
  1452 
  1453 INCOMPATIBILITIES:
  1454 
  1455   - Theories using datatypes must now have theory Datatype as an
  1456     ancestor.
  1457   - The specific <typename>.induct_tac no longer exists - use the
  1458     generic induct_tac instead.
  1459   - natE has been renamed to nat.exhaust - use exhaust_tac
  1460     instead of res_inst_tac ... natE. Note that the variable
  1461     names in nat.exhaust differ from the names in natE, this
  1462     may cause some "fragile" proofs to fail.
  1463   - The theorems split_<typename>_case and split_<typename>_case_asm
  1464     have been renamed to <typename>.split and <typename>.split_asm.
  1465   - Since default sorts of type variables are now handled correctly,
  1466     some datatype definitions may have to be annotated with explicit
  1467     sort constraints.
  1468   - Primrec definitions no longer require function name and type
  1469     of recursive argument.
  1470 
  1471 Consider using isatool fixdatatype to adapt your theories and proof
  1472 scripts to the new package (backup your sources first!).
  1473 
  1474 
  1475 * HOL/record package: considerably improved implementation; now
  1476 includes concrete syntax for record types, terms, updates; theorems
  1477 for surjective pairing and splitting !!-bound record variables; proof
  1478 support is as follows:
  1479 
  1480   1) standard conversions (selectors or updates applied to record
  1481 constructor terms) are part of the standard simpset;
  1482 
  1483   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  1484 made part of standard simpset and claset via addIffs;
  1485 
  1486   3) a tactic for record field splitting (record_split_tac) is part of
  1487 the standard claset (addSWrapper);
  1488 
  1489 To get a better idea about these rules you may retrieve them via
  1490 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  1491 the name of your record type.
  1492 
  1493 The split tactic 3) conceptually simplifies by the following rule:
  1494 
  1495   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  1496 
  1497 Thus any record variable that is bound by meta-all will automatically
  1498 blow up into some record constructor term, consequently the
  1499 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  1500 solve record problems automatically.
  1501 
  1502 
  1503 * reorganized the main HOL image: HOL/Integ and String loaded by
  1504 default; theory Main includes everything;
  1505 
  1506 * automatic simplification of integer sums and comparisons, using cancellation;
  1507 
  1508 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  1509 
  1510 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  1511 
  1512 * many new identities for unions, intersections, set difference, etc.;
  1513 
  1514 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  1515 called split_if, split_split, split_sum_case and split_nat_case (to go
  1516 with add/delsplits);
  1517 
  1518 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  1519 (?x::unit) = (); this is made part of the default simpset, which COULD
  1520 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  1521 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  1522 unit_abs_eta_conv is added in order to counter the effect of
  1523 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  1524 %u.f();
  1525 
  1526 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  1527 makes more sense);
  1528 
  1529 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1530   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1531   disjointness reasoning but breaking a few old proofs.
  1532 
  1533 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  1534 to 'converse' from 'inverse' (for compatibility with ZF and some
  1535 literature);
  1536 
  1537 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  1538 the well-founded relation;
  1539 
  1540 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  1541     Compl A.  The "Compl" syntax remains available as input syntax for this
  1542     release ONLY.
  1543 
  1544 * HOL/Update: new theory of function updates:
  1545     f(a:=b) == %x. if x=a then b else f x
  1546 may also be iterated as in f(a:=b,c:=d,...);
  1547 
  1548 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  1549 
  1550 * HOL/List:
  1551   - new function list_update written xs[i:=v] that updates the i-th
  1552     list position. May also be iterated as in xs[i:=a,j:=b,...].
  1553   - new function `upt' written [i..j(] which generates the list
  1554     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  1555     bound write [i..j], which is a shorthand for [i..j+1(].
  1556   - new lexicographic orderings and corresponding wellfoundedness theorems.
  1557 
  1558 * HOL/Arith:
  1559   - removed 'pred' (predecessor) function;
  1560   - generalized some theorems about n-1;
  1561   - many new laws about "div" and "mod";
  1562   - new laws about greatest common divisors (see theory ex/Primes);
  1563 
  1564 * HOL/Relation: renamed the relational operator r^-1 "converse"
  1565 instead of "inverse";
  1566 
  1567 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  1568   of the multiset ordering;
  1569 
  1570 * directory HOL/Real: a construction of the reals using Dedekind cuts
  1571   (not included by default);
  1572 
  1573 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  1574 
  1575 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  1576   programs, i.e. different program variables may have different types.
  1577 
  1578 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1579   [previously, this check worked only if the rewrite rule was unconditional]
  1580   Now rew can involve either definitions or equalities (either == or =).
  1581 
  1582 
  1583 *** ZF ***
  1584 
  1585 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  1586   only the theorems proved on ZF.ML;
  1587 
  1588 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1589   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1590   disjointness reasoning but breaking a few old proofs.
  1591 
  1592 * ZF/Update: new theory of function updates
  1593     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  1594   may also be iterated as in f(a:=b,c:=d,...);
  1595 
  1596 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  1597 
  1598 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1599   [previously, this check worked only if the rewrite rule was unconditional]
  1600   Now rew can involve either definitions or equalities (either == or =).
  1601 
  1602 * case_tac provided for compatibility with HOL
  1603     (like the old excluded_middle_tac, but with subgoals swapped)
  1604 
  1605 
  1606 *** Internal programming interfaces ***
  1607 
  1608 * Pure: several new basic modules made available for general use, see
  1609 also src/Pure/README;
  1610 
  1611 * improved the theory data mechanism to support encapsulation (data
  1612 kind name replaced by private Object.kind, acting as authorization
  1613 key); new type-safe user interface via functor TheoryDataFun; generic
  1614 print_data function becomes basically useless;
  1615 
  1616 * removed global_names compatibility flag -- all theory declarations
  1617 are qualified by default;
  1618 
  1619 * module Pure/Syntax now offers quote / antiquote translation
  1620 functions (useful for Hoare logic etc. with implicit dependencies);
  1621 see HOL/ex/Antiquote for an example use;
  1622 
  1623 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  1624 cterm -> thm;
  1625 
  1626 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  1627 subgoal;
  1628 
  1629 * Display.print_goals function moved to Locale.print_goals;
  1630 
  1631 * standard print function for goals supports current_goals_markers
  1632 variable for marking begin of proof, end of proof, start of goal; the
  1633 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  1634 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  1635 for example;
  1636 
  1637 
  1638 
  1639 New in Isabelle98 (January 1998)
  1640 --------------------------------
  1641 
  1642 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1643 
  1644 * changed lexical syntax of terms / types: dots made part of long
  1645 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  1646 
  1647 * simpset (and claset) reference variable replaced by functions
  1648 simpset / simpset_ref;
  1649 
  1650 * no longer supports theory aliases (via merge) and non-trivial
  1651 implicit merge of thms' signatures;
  1652 
  1653 * most internal names of constants changed due to qualified names;
  1654 
  1655 * changed Pure/Sequence interface (see Pure/seq.ML);
  1656 
  1657 
  1658 *** General Changes ***
  1659 
  1660 * hierachically structured name spaces (for consts, types, axms, thms
  1661 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  1662 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  1663 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  1664 long_names for fully qualified output names; NOTE: ML programs
  1665 (special tactics, packages etc.) referring to internal names may have
  1666 to be adapted to cope with fully qualified names; in case of severe
  1667 backward campatibility problems try setting 'global_names' at compile
  1668 time to have enrything declared within a flat name space; one may also
  1669 fine tune name declarations in theories via the 'global' and 'local'
  1670 section;
  1671 
  1672 * reimplemented the implicit simpset and claset using the new anytype
  1673 data filed in signatures; references simpset:simpset ref etc. are
  1674 replaced by functions simpset:unit->simpset and
  1675 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  1676 to patch your ML files accordingly;
  1677 
  1678 * HTML output now includes theory graph data for display with Java
  1679 applet or isatool browser; data generated automatically via isatool
  1680 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  1681 
  1682 * defs may now be conditional; improved rewrite_goals_tac to handle
  1683 conditional equations;
  1684 
  1685 * defs now admits additional type arguments, using TYPE('a) syntax;
  1686 
  1687 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  1688 creates a new theory node; implicit merge of thms' signatures is
  1689 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  1690 transfer:theory->thm->thm in (rare) cases;
  1691 
  1692 * improved handling of draft signatures / theories; draft thms (and
  1693 ctyps, cterms) are automatically promoted to real ones;
  1694 
  1695 * slightly changed interfaces for oracles: admit many per theory, named
  1696 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  1697 
  1698 * print_goals: optional output of const types (set show_consts and
  1699 show_types);
  1700 
  1701 * improved output of warnings (###) and errors (***);
  1702 
  1703 * subgoal_tac displays a warning if the new subgoal has type variables;
  1704 
  1705 * removed old README and Makefiles;
  1706 
  1707 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  1708 
  1709 * removed obsolete init_pps and init_database;
  1710 
  1711 * deleted the obsolete tactical STATE, which was declared by
  1712     fun STATE tacfun st = tacfun st st;
  1713 
  1714 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  1715 (which abbreviates $HOME);
  1716 
  1717 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  1718 use isatool fixseq to adapt your ML programs (this works for fully
  1719 qualified references to the Sequence structure only!);
  1720 
  1721 * use_thy no longer requires writable current directory; it always
  1722 reloads .ML *and* .thy file, if either one is out of date;
  1723 
  1724 
  1725 *** Classical Reasoner ***
  1726 
  1727 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  1728 tactics that use classical reasoning to simplify a subgoal without
  1729 splitting it into several subgoals;
  1730 
  1731 * Safe_tac: like safe_tac but uses the default claset;
  1732 
  1733 
  1734 *** Simplifier ***
  1735 
  1736 * added simplification meta rules:
  1737     (asm_)(full_)simplify: simpset -> thm -> thm;
  1738 
  1739 * simplifier.ML no longer part of Pure -- has to be loaded by object
  1740 logics (again);
  1741 
  1742 * added prems argument to simplification procedures;
  1743 
  1744 * HOL, FOL, ZF: added infix function `addsplits':
  1745   instead of `<simpset> setloop (split_tac <thms>)'
  1746   you can simply write `<simpset> addsplits <thms>'
  1747 
  1748 
  1749 *** Syntax ***
  1750 
  1751 * TYPE('a) syntax for type reflection terms;
  1752 
  1753 * no longer handles consts with name "" -- declare as 'syntax' instead;
  1754 
  1755 * pretty printer: changed order of mixfix annotation preference (again!);
  1756 
  1757 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  1758 
  1759 
  1760 *** HOL ***
  1761 
  1762 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1763   with `addloop' of the simplifier to faciliate case splitting in premises.
  1764 
  1765 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  1766 
  1767 * HOL/Auth: new protocol proofs including some for the Internet
  1768   protocol TLS;
  1769 
  1770 * HOL/Map: new theory of `maps' a la VDM;
  1771 
  1772 * HOL/simplifier: simplification procedures nat_cancel_sums for
  1773 cancelling out common nat summands from =, <, <= (in)equalities, or
  1774 differences; simplification procedures nat_cancel_factor for
  1775 cancelling common factor from =, <, <= (in)equalities over natural
  1776 sums; nat_cancel contains both kinds of procedures, it is installed by
  1777 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  1778 
  1779 * HOL/simplifier: terms of the form
  1780   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  1781   are rewritten to
  1782   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  1783   and those of the form
  1784   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  1785   are rewritten to
  1786   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  1787 
  1788 * HOL/datatype
  1789   Each datatype `t' now comes with a theorem `split_t_case' of the form
  1790 
  1791   P(t_case f1 ... fn x) =
  1792      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  1793         ...
  1794        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  1795      )
  1796 
  1797   and a theorem `split_t_case_asm' of the form
  1798 
  1799   P(t_case f1 ... fn x) =
  1800     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  1801         ...
  1802        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  1803      )
  1804   which can be added to a simpset via `addsplits'. The existing theorems
  1805   expand_list_case and expand_option_case have been renamed to
  1806   split_list_case and split_option_case.
  1807 
  1808 * HOL/Arithmetic:
  1809   - `pred n' is automatically converted to `n-1'.
  1810     Users are strongly encouraged not to use `pred' any longer,
  1811     because it will disappear altogether at some point.
  1812   - Users are strongly encouraged to write "0 < n" rather than
  1813     "n ~= 0". Theorems and proof tools have been modified towards this
  1814     `standard'.
  1815 
  1816 * HOL/Lists:
  1817   the function "set_of_list" has been renamed "set" (and its theorems too);
  1818   the function "nth" now takes its arguments in the reverse order and
  1819   has acquired the infix notation "!" as in "xs!n".
  1820 
  1821 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  1822 
  1823 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  1824   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  1825 
  1826 * HOL/record: extensible records with schematic structural subtyping
  1827 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  1828 still lacks various theorems and concrete record syntax;
  1829 
  1830 
  1831 *** HOLCF ***
  1832 
  1833 * removed "axioms" and "generated by" sections;
  1834 
  1835 * replaced "ops" section by extended "consts" section, which is capable of
  1836   handling the continuous function space "->" directly;
  1837 
  1838 * domain package:
  1839   . proves theorems immediately and stores them in the theory,
  1840   . creates hierachical name space,
  1841   . now uses normal mixfix annotations (instead of cinfix...),
  1842   . minor changes to some names and values (for consistency),
  1843   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  1844   . separator between mutual domain defs: changed "," to "and",
  1845   . improved handling of sort constraints;  now they have to
  1846     appear on the left-hand side of the equations only;
  1847 
  1848 * fixed LAM <x,y,zs>.b syntax;
  1849 
  1850 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  1851 adm (%x. P (t x)), where P is chainfinite and t continuous;
  1852 
  1853 
  1854 *** FOL and ZF ***
  1855 
  1856 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1857   with `addloop' of the simplifier to faciliate case splitting in premises.
  1858 
  1859 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  1860 in HOL, they strip ALL and --> from proved theorems;
  1861 
  1862 
  1863 
  1864 New in Isabelle94-8 (May 1997)
  1865 ------------------------------
  1866 
  1867 *** General Changes ***
  1868 
  1869 * new utilities to build / run / maintain Isabelle etc. (in parts
  1870 still somewhat experimental); old Makefiles etc. still functional;
  1871 
  1872 * new 'Isabelle System Manual';
  1873 
  1874 * INSTALL text, together with ./configure and ./build scripts;
  1875 
  1876 * reimplemented type inference for greater efficiency, better error
  1877 messages and clean internal interface;
  1878 
  1879 * prlim command for dealing with lots of subgoals (an easier way of
  1880 setting goals_limit);
  1881 
  1882 
  1883 *** Syntax ***
  1884 
  1885 * supports alternative (named) syntax tables (parser and pretty
  1886 printer); internal interface is provided by add_modesyntax(_i);
  1887 
  1888 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  1889 be used in conjunction with the Isabelle symbol font; uses the
  1890 "symbols" syntax table;
  1891 
  1892 * added token_translation interface (may translate name tokens in
  1893 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  1894 the current print_mode); IMPORTANT: user print translation functions
  1895 are responsible for marking newly introduced bounds
  1896 (Syntax.mark_boundT);
  1897 
  1898 * token translations for modes "xterm" and "xterm_color" that display
  1899 names in bold, underline etc. or colors (which requires a color
  1900 version of xterm);
  1901 
  1902 * infixes may now be declared with names independent of their syntax;
  1903 
  1904 * added typed_print_translation (like print_translation, but may
  1905 access type of constant);
  1906 
  1907 
  1908 *** Classical Reasoner ***
  1909 
  1910 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  1911 some limitations.  Blast_tac...
  1912   + ignores addss, addbefore, addafter; this restriction is intrinsic
  1913   + ignores elimination rules that don't have the correct format
  1914         (the conclusion MUST be a formula variable)
  1915   + ignores types, which can make HOL proofs fail
  1916   + rules must not require higher-order unification, e.g. apply_type in ZF
  1917     [message "Function Var's argument not a bound variable" relates to this]
  1918   + its proof strategy is more general but can actually be slower
  1919 
  1920 * substitution with equality assumptions no longer permutes other
  1921 assumptions;
  1922 
  1923 * minor changes in semantics of addafter (now called addaltern); renamed
  1924 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  1925 (and access functions for it);
  1926 
  1927 * improved combination of classical reasoner and simplifier:
  1928   + functions for handling clasimpsets
  1929   + improvement of addss: now the simplifier is called _after_ the
  1930     safe steps.
  1931   + safe variant of addss called addSss: uses safe simplifications
  1932     _during_ the safe steps. It is more complete as it allows multiple
  1933     instantiations of unknowns (e.g. with slow_tac).
  1934 
  1935 *** Simplifier ***
  1936 
  1937 * added interface for simplification procedures (functions that
  1938 produce *proven* rewrite rules on the fly, depending on current
  1939 redex);
  1940 
  1941 * ordering on terms as parameter (used for ordered rewriting);
  1942 
  1943 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  1944 
  1945 * the solver is now split into a safe and an unsafe part.
  1946 This should be invisible for the normal user, except that the
  1947 functions setsolver and addsolver have been renamed to setSolver and
  1948 addSolver; added safe_asm_full_simp_tac;
  1949 
  1950 
  1951 *** HOL ***
  1952 
  1953 * a generic induction tactic `induct_tac' which works for all datatypes and
  1954 also for type `nat';
  1955 
  1956 * a generic case distinction tactic `exhaust_tac' which works for all
  1957 datatypes and also for type `nat';
  1958 
  1959 * each datatype comes with a function `size';
  1960 
  1961 * patterns in case expressions allow tuple patterns as arguments to
  1962 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  1963 
  1964 * primrec now also works with type nat;
  1965 
  1966 * recdef: a new declaration form, allows general recursive functions to be
  1967 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  1968 
  1969 * the constant for negation has been renamed from "not" to "Not" to
  1970 harmonize with FOL, ZF, LK, etc.;
  1971 
  1972 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  1973 infinite lists;
  1974 
  1975 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  1976 
  1977 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  1978 problems in commutative rings, using axiomatic type classes for + and *;
  1979 
  1980 * more examples in HOL/MiniML and HOL/Auth;
  1981 
  1982 * more default rewrite rules for quantifiers, union/intersection;
  1983 
  1984 * a new constant `arbitrary == @x.False';
  1985 
  1986 * HOLCF/IOA replaces old HOL/IOA;
  1987 
  1988 * HOLCF changes: derived all rules and arities
  1989   + axiomatic type classes instead of classes
  1990   + typedef instead of faking type definitions
  1991   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  1992   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  1993   + eliminated the types void, one, tr
  1994   + use unit lift and bool lift (with translations) instead of one and tr
  1995   + eliminated blift from Lift3.thy (use Def instead of blift)
  1996   all eliminated rules are derived as theorems --> no visible changes ;
  1997 
  1998 
  1999 *** ZF ***
  2000 
  2001 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  2002 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  2003 as ZF_cs addSIs [equalityI];
  2004 
  2005 
  2006 
  2007 New in Isabelle94-7 (November 96)
  2008 ---------------------------------
  2009 
  2010 * allowing negative levels (as offsets) in prlev and choplev;
  2011 
  2012 * super-linear speedup for large simplifications;
  2013 
  2014 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  2015 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  2016 FAIL); can suppress it using the command Delsimps (ex_simps @
  2017 all_simps); De Morgan laws are also now included, by default;
  2018 
  2019 * improved printing of ==>  :  ~:
  2020 
  2021 * new object-logic "Sequents" adds linear logic, while replacing LK
  2022 and Modal (thanks to Sara Kalvala);
  2023 
  2024 * HOL/Auth: correctness proofs for authentication protocols;
  2025 
  2026 * HOL: new auto_tac combines rewriting and classical reasoning (many
  2027 examples on HOL/Auth);
  2028 
  2029 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  2030 the rewriter and classical reasoner simultaneously;
  2031 
  2032 * function uresult no longer returns theorems in "standard" format;
  2033 regain previous version by: val uresult = standard o uresult;
  2034 
  2035 
  2036 
  2037 New in Isabelle94-6
  2038 -------------------
  2039 
  2040 * oracles -- these establish an interface between Isabelle and trusted
  2041 external reasoners, which may deliver results as theorems;
  2042 
  2043 * proof objects (in particular record all uses of oracles);
  2044 
  2045 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  2046 
  2047 * "constdefs" section in theory files;
  2048 
  2049 * "primrec" section (HOL) no longer requires names;
  2050 
  2051 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  2052 
  2053 
  2054 
  2055 New in Isabelle94-5
  2056 -------------------
  2057 
  2058 * reduced space requirements;
  2059 
  2060 * automatic HTML generation from theories;
  2061 
  2062 * theory files no longer require "..." (quotes) around most types;
  2063 
  2064 * new examples, including two proofs of the Church-Rosser theorem;
  2065 
  2066 * non-curried (1994) version of HOL is no longer distributed;
  2067 
  2068 
  2069 
  2070 New in Isabelle94-4
  2071 -------------------
  2072 
  2073 * greatly reduced space requirements;
  2074 
  2075 * theory files (.thy) no longer require \...\ escapes at line breaks;
  2076 
  2077 * searchable theorem database (see the section "Retrieving theorems" on
  2078 page 8 of the Reference Manual);
  2079 
  2080 * new examples, including Grabczewski's monumental case study of the
  2081 Axiom of Choice;
  2082 
  2083 * The previous version of HOL renamed to Old_HOL;
  2084 
  2085 * The new version of HOL (previously called CHOL) uses a curried syntax
  2086 for functions.  Application looks like f a b instead of f(a,b);
  2087 
  2088 * Mutually recursive inductive definitions finally work in HOL;
  2089 
  2090 * In ZF, pattern-matching on tuples is now available in all abstractions and
  2091 translates to the operator "split";
  2092 
  2093 
  2094 
  2095 New in Isabelle94-3
  2096 -------------------
  2097 
  2098 * new infix operator, addss, allowing the classical reasoner to
  2099 perform simplification at each step of its search.  Example:
  2100         fast_tac (cs addss ss)
  2101 
  2102 * a new logic, CHOL, the same as HOL, but with a curried syntax
  2103 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  2104 look like (a,b) instead of <a,b>;
  2105 
  2106 * PLEASE NOTE: CHOL will eventually replace HOL!
  2107 
  2108 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  2109 It translates to the operator "split".  A new theory of integers is available;
  2110 
  2111 * In ZF, integer numerals now denote two's-complement binary integers.
  2112 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  2113 
  2114 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  2115 of the Axiom of Choice;
  2116 
  2117 
  2118 
  2119 New in Isabelle94-2
  2120 -------------------
  2121 
  2122 * Significantly faster resolution;
  2123 
  2124 * the different sections in a .thy file can now be mixed and repeated
  2125 freely;
  2126 
  2127 * Database of theorems for FOL, HOL and ZF.  New
  2128 commands including qed, qed_goal and bind_thm store theorems in the database.
  2129 
  2130 * Simple database queries: return a named theorem (get_thm) or all theorems of
  2131 a given theory (thms_of), or find out what theory a theorem was proved in
  2132 (theory_of_thm);
  2133 
  2134 * Bugs fixed in the inductive definition and datatype packages;
  2135 
  2136 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  2137 and HOL_dup_cs obsolete;
  2138 
  2139 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  2140 have been removed;
  2141 
  2142 * Simpler definition of function space in ZF;
  2143 
  2144 * new results about cardinal and ordinal arithmetic in ZF;
  2145 
  2146 * 'subtype' facility in HOL for introducing new types as subsets of existing
  2147 types;
  2148 
  2149 
  2150 $Id$