NEWS
author wenzelm
Thu Jan 03 17:50:53 2002 +0100 (2002-01-03)
changeset 12622 7592926925d4
parent 12608 2df381faa787
child 12690 ac3fa7c05e5a
permissions -rw-r--r--
tuned;
     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;
    31 
    32 
    33 *** Isar ***
    34 
    35 * Pure/Provers: improved proof by cases and induction;
    36   - 'case' command admits impromptu naming of parameters (such as
    37     "case (Suc n)");
    38   - 'induct' method divinates rule instantiation from the inductive
    39     claim; no longer requires excessive ?P bindings for proper
    40     instantiation of cases;
    41   - 'induct' method properly enumerates all possibilities of set/type
    42     rules; as a consequence facts may be also passed through *type*
    43     rules without further ado;
    44   - 'induct' method now derives symbolic cases from the *rulified*
    45     rule (before it used to rulify cases stemming from the internal
    46     atomized version); this means that the context of a non-atomic
    47     statement becomes is included in the hypothesis, avoiding the
    48     slightly cumbersome show "PROP ?case" form;
    49   - 'induct' may now use elim-style induction rules without chaining
    50     facts, using ``missing'' premises from the goal state; this allows
    51     rules stemming from inductive sets to be applied in unstructured
    52     scripts, while still benefitting from proper handling of non-atomic
    53     statements; NB: major inductive premises need to be put first, all
    54     the rest of the goal is passed through the induction;
    55   - 'induct' proper support for mutual induction involving non-atomic
    56     rule statements (uses the new concept of simultaneous goals, see
    57     below);
    58   - removed obsolete "(simplified)" and "(stripped)" options of methods;
    59   - added 'print_induct_rules' (covered by help item in Proof General > 3.3);
    60   - moved induct/cases attributes to Pure, methods to Provers;
    61   - generic method setup instantiated for FOL and HOL;
    62 
    63 * Pure: support multiple simultaneous goal statements, for example
    64 "have a: A and b: B" (same for 'theorem' etc.); being a pure
    65 meta-level mechanism, this acts as if several individual goals had
    66 been stated separately; in particular common proof methods need to be
    67 repeated in order to cover all claims; note that a single elimination
    68 step is *not* sufficient to establish the two conjunctions, so this
    69 fails:
    70 
    71   assume "A & B" then have A and B ..   (*".." fails*)
    72 
    73 better use "obtain" in situations as above; alternative refer to
    74 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
    75 
    76 * Pure: proper integration with ``locales''; unlike the original
    77 version by Florian Kammüller, Isar locales package high-level proof
    78 contexts rather than raw logical ones (e.g. we admit to include
    79 attributes everywhere); operations on locales include merge and
    80 rename; e.g. see HOL/ex/Locales.thy;
    81 
    82 * Pure: theory goals now support ad-hoc contexts, which are discharged
    83 in the result, as in ``lemma (assumes A and B) K: A .''; syntax
    84 coincides with that of a locale body;
    85 
    86 * Pure: renamed "antecedent" case to "rule_context";
    87 
    88 * Pure: added 'corollary' command;
    89 
    90 * Pure: fixed 'token_translation' command;
    91 
    92 * Pure: removed obsolete 'exported' attribute;
    93 
    94 * Pure: dummy pattern "_" in is/let is now automatically lifted over
    95 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
    96 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
    97 
    98 * Pure: method 'atomize' presents local goal premises as object-level
    99 statements (atomic meta-level propositions); setup controlled via
   100 rewrite rules declarations of 'atomize' attribute; example
   101 application: 'induct' method with proper rule statements in improper
   102 proof *scripts*;
   103 
   104 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
   105 now consider the syntactic context of assumptions, giving a better
   106 chance to get type-inference of the arguments right (this is
   107 especially important for locales);
   108 
   109 * Pure: "sorry" no longer requires quick_and_dirty in interactive
   110 mode;
   111 
   112 * Pure/obtain: the formal conclusion "thesis", being marked as
   113 ``internal'', may no longer be reference directly in the text;
   114 potential INCOMPATIBILITY, may need to use "?thesis" in rare
   115 situations;
   116 
   117 * Pure: generic 'sym' attribute which declares a rule both as pure
   118 'elim?' and for the 'symmetric' operation;
   119 
   120 * Pure/Provers/classical: simplified integration with pure rule
   121 attributes and methods; the classical "intro?/elim?/dest?"
   122 declarations coincide with the pure ones; the "rule" method no longer
   123 includes classically swapped intros; "intro" and "elim" methods no
   124 longer pick rules from the context; also got rid of ML declarations
   125 AddXIs/AddXEs/AddXDs; all of this has some potential for
   126 INCOMPATIBILITY;
   127 
   128 * Provers/classical: attribute 'swapped' produces classical inversions
   129 of introduction rules;
   130 
   131 * Provers/simplifier: 'simplified' attribute may refer to explicit
   132 rules instead of full simplifier context; 'iff' attribute handles
   133 conditional rules;
   134 
   135 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
   136 
   137 * HOL: 'recdef' now fails on unfinished automated proofs, use
   138 "(permissive)" option to recover old behavior;
   139 
   140 * HOL: 'inductive' no longer features separate (collective) attributes
   141 for 'intros' (was found too confusing);
   142 
   143 * HOL: properly declared induction rules less_induct and
   144 wf_induct_rule;
   145 
   146 
   147 *** HOL ***
   148 
   149 * HOL: moved over to sane numeral syntax; the new policy is as
   150 follows:
   151 
   152   - 0 and 1 are polymorphic constants, which are defined on any
   153   numeric type (nat, int, real etc.);
   154 
   155   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
   156   binary representation internally;
   157 
   158   - type nat has special constructor Suc, and generally prefers Suc 0
   159   over 1::nat and Suc (Suc 0) over 2::nat;
   160 
   161 This change may cause significant problems of INCOMPATIBILITY; here
   162 are some hints on converting existing sources:
   163 
   164   - due to the new "num" token, "-0" and "-1" etc. are now atomic
   165   entities, so expressions involving "-" (unary or binary minus) need
   166   to be spaced properly;
   167 
   168   - existing occurrences of "1" may need to be constraint "1::nat" or
   169   even replaced by Suc 0; similar for old "2";
   170 
   171   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
   172 
   173   - remove all special provisions on numerals in proofs;
   174 
   175 * HOL: the class of all HOL types is now called "type" rather than
   176 "term"; INCOMPATIBILITY, need to adapt references to this type class
   177 in axclass/classes, instance/arities, and (usually rare) occurrences
   178 in typings (of consts etc.); internally the class is called
   179 "HOL.type", ML programs should refer to HOLogic.typeS;
   180 
   181 * HOL/record package improvements:
   182   - new derived operations "fields" to build a partial record section,
   183     "extend" to promote a fixed record to a record scheme, and
   184     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
   185     declared as simp by default;
   186   - shared operations ("more", "fields", etc.) now need to be always
   187     qualified) --- potential INCOMPATIBILITY;
   188   - removed "make_scheme" operations (use "make" with "extend") --
   189     INCOMPATIBILITY;
   190   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
   191   - provides cases/induct rules for use with corresponding Isar
   192     methods (for concrete records, record schemes, concrete more
   193     parts, and schematic more parts -- in that order);
   194   - internal definitions directly based on a light-weight abstract
   195     theory of product types over typedef rather than datatype;
   196 
   197 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
   198 
   199 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
   200 (beware of argument permutation!);
   201 
   202 * HOL: linorder_less_split superseded by linorder_cases;
   203 
   204 * HOL: added "The" definite description operator; move Hilbert's "Eps"
   205 to peripheral theory "Hilbert_Choice";
   206 
   207 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
   208 in this (rare) case use:
   209 
   210   delSWrapper "split_all_tac"
   211   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
   212 
   213 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
   214 MAY FAIL;
   215 
   216 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
   217 Isabelle's type classes, ^ on functions and relations has too general
   218 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
   219 necessary to attach explicit type constraints;
   220 
   221 * HOL/Relation: the prefix name of the infix "O" has been changed from "comp"
   222 to "rel_comp"; INCOMPATIBILITY: a few theorems have been renamed accordingly
   223 (eg "compI" -> "rel_compI").
   224 
   225 * HOL: syntax translations now work properly with numerals and records
   226 expressions;
   227 
   228 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
   229 of "lam" -- INCOMPATIBILITY;
   230 
   231 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
   232 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
   233 renamed "Product_Type.unit";
   234 
   235 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
   236 
   237 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
   238 Florian Kammüller);
   239 
   240 * HOL/IMP: updated and converted to new-style theory format; several
   241 parts turned into readable document, with proper Isar proof texts and
   242 some explanations (by Gerwin Klein);
   243 
   244 
   245 *** HOLCF ***
   246 
   247 * Isar: consts/constdefs supports mixfix syntax for continuous
   248 operations;
   249 
   250 * Isar: domain package adapted to new-style theory format, e.g. see
   251 HOLCF/ex/Dnat.thy;
   252 
   253 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
   254 potential INCOMPATIBILITY; now use plain induct_tac instead of former
   255 lift.induct_tac, always use UU instead of Undef;
   256 
   257 * HOLCF/IMP: updated and converted to new-style theory;
   258 
   259 
   260 *** ZF ***
   261 
   262 * Isar: proper integration of logic-specific tools and packages,
   263 including theory commands '(co)inductive', '(co)datatype',
   264 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
   265 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
   266 
   267 * theory Main no longer includes AC; for the Axiom of Choice, base
   268 your theory on Main_ZFC;
   269 
   270 * the integer library now covers quotients and remainders, with many
   271 laws relating division to addition, multiplication, etc.;
   272 
   273 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
   274 typeless version of the formalism;
   275 
   276 * ZF/IMP: updated and converted to new-style theory format;
   277 
   278 * ZF/Induct: new directory for examples of inductive definitions,
   279 including theory Multiset for multiset orderings; converted to
   280 new-style theory format;
   281 
   282 
   283 *** General ***
   284 
   285 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
   286 variable proof controls level of detail: 0 = no proofs (only oracle
   287 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
   288 also ref manual for further ML interfaces;
   289 
   290 * Pure/axclass: removed obsolete ML interface
   291 goal_subclass/goal_arity;
   292 
   293 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
   294 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
   295 separate tokens, so expressions involving minus need to be spaced
   296 properly;
   297 
   298 * Pure/syntax: support non-oriented infixes, using keyword "infix"
   299 rather than "infixl" or "infixr";
   300 
   301 * Pure/syntax: concrete syntax for dummy type variables admits genuine
   302 sort constraint specifications in type inference; e.g. "x::_::foo"
   303 ensures that the type of "x" is of sort "foo" (but not necessarily a
   304 type variable);
   305 
   306 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
   307 control output of nested => (types); the default behavior is
   308 "type_brackets";
   309 
   310 * Pure/syntax: builtin parse translation for "_constify" turns valued
   311 tokens into AST constants;
   312 
   313 * Pure/syntax: prefer later declarations of translations and print
   314 translation functions; potential INCOMPATIBILITY: need to reverse
   315 multiple declarations for same syntax element constant;
   316 
   317 * Provers/classical: renamed addaltern to addafter, addSaltern to
   318 addSafter;
   319 
   320 * Provers/clasimp: ``iff'' declarations now handle conditional rules
   321 as well;
   322 
   323 * system: tested support for MacOS X; should be able to get Isabelle +
   324 Proof General to work in a plain Terminal after installing Poly/ML
   325 (e.g. from the Isabelle distribution area) and GNU bash alone
   326 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
   327 support requires further installations, e.g. from
   328 http://fink.sourceforge.net/);
   329 
   330 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
   331 
   332 * system: Proof General keywords specification is now part of the
   333 Isabelle distribution (see etc/isar-keywords.el);
   334 
   335 * system: some support for persistent Proof General sessions (refrain
   336 from outdating all loaded theories on startup);
   337 
   338 * system: smart selection of Isabelle process versus Isabelle
   339 interface, accommodates case-insensitive file systems (e.g. HFS+); may
   340 run both "isabelle" and "Isabelle" even if file names are badly
   341 damaged (executable inspects the case of the first letter of its own
   342 name); added separate "isabelle-process" and "isabelle-interface";
   343 
   344 * system: refrain from any attempt at filtering input streams; no
   345 longer support ``8bit'' encoding of old isabelle font, instead proper
   346 iso-latin characters may now be used; the related isatools
   347 "symbolinput" and "nonascii" have disappeared as well;
   348 
   349 * system: removed old "xterm" interface (the print modes "xterm" and
   350 "xterm_color" are still available for direct use in a suitable
   351 terminal);
   352 
   353 
   354 
   355 New in Isabelle99-2 (February 2001)
   356 -----------------------------------
   357 
   358 *** Overview of INCOMPATIBILITIES ***
   359 
   360 * HOL: please note that theories in the Library and elsewhere often use the
   361 new-style (Isar) format; to refer to their theorems in an ML script you must
   362 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
   363 
   364 * HOL: inductive package no longer splits induction rule aggressively,
   365 but only as far as specified by the introductions given; the old
   366 format may be recovered via ML function complete_split_rule or attribute
   367 'split_rule (complete)';
   368 
   369 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
   370 gfp_Tarski to gfp_unfold;
   371 
   372 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
   373 
   374 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
   375 relation); infix "^^" has been renamed "``"; infix "``" has been
   376 renamed "`"; "univalent" has been renamed "single_valued";
   377 
   378 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
   379 operation;
   380 
   381 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
   382 
   383 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
   384 
   385 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
   386 consequence, it is no longer monotonic wrt. the local goal context
   387 (which is now passed through the inductive cases);
   388 
   389 * Document preparation: renamed standard symbols \<ll> to \<lless> and
   390 \<gg> to \<ggreater>;
   391 
   392 
   393 *** Document preparation ***
   394 
   395 * \isabellestyle{NAME} selects version of Isabelle output (currently
   396 available: are "it" for near math-mode best-style output, "sl" for
   397 slanted text style, and "tt" for plain type-writer; if no
   398 \isabellestyle command is given, output is according to slanted
   399 type-writer);
   400 
   401 * support sub/super scripts (for single symbols only), input syntax is
   402 like this: "A\<^sup>*" or "A\<^sup>\<star>";
   403 
   404 * some more standard symbols; see Appendix A of the system manual for
   405 the complete list of symbols defined in isabellesym.sty;
   406 
   407 * improved isabelle style files; more abstract symbol implementation
   408 (should now use \isamath{...} and \isatext{...} in custom symbol
   409 definitions);
   410 
   411 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
   412 state; Note that presentation of goal states does not conform to
   413 actual human-readable proof documents.  Please do not include goal
   414 states into document output unless you really know what you are doing!
   415 
   416 * proper indentation of antiquoted output with proportional LaTeX
   417 fonts;
   418 
   419 * no_document ML operator temporarily disables LaTeX document
   420 generation;
   421 
   422 * isatool unsymbolize tunes sources for plain ASCII communication;
   423 
   424 
   425 *** Isar ***
   426 
   427 * Pure: Isar now suffers initial goal statements to contain unbound
   428 schematic variables (this does not conform to actual readable proof
   429 documents, due to unpredictable outcome and non-compositional proof
   430 checking); users who know what they are doing may use schematic goals
   431 for Prolog-style synthesis of proven results;
   432 
   433 * Pure: assumption method (an implicit finishing) now handles actual
   434 rules as well;
   435 
   436 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
   437 initial goal, declare "that" only as Pure intro (only for single
   438 steps); the "that" rule assumption may now be involved in implicit
   439 finishing, thus ".." becomes a feasible for trivial obtains;
   440 
   441 * Pure: default proof step now includes 'intro_classes'; thus trivial
   442 instance proofs may be performed by "..";
   443 
   444 * Pure: ?thesis / ?this / "..." now work for pure meta-level
   445 statements as well;
   446 
   447 * Pure: more robust selection of calculational rules;
   448 
   449 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
   450 rule (as well as the assumption rule);
   451 
   452 * Pure: 'thm_deps' command visualizes dependencies of theorems and
   453 lemmas, using the graph browser tool;
   454 
   455 * Pure: predict failure of "show" in interactive mode;
   456 
   457 * Pure: 'thms_containing' now takes actual terms as arguments;
   458 
   459 * HOL: improved method 'induct' --- now handles non-atomic goals
   460 (potential INCOMPATIBILITY); tuned error handling;
   461 
   462 * HOL: cases and induct rules now provide explicit hints about the
   463 number of facts to be consumed (0 for "type" and 1 for "set" rules);
   464 any remaining facts are inserted into the goal verbatim;
   465 
   466 * HOL: local contexts (aka cases) may now contain term bindings as
   467 well; the 'cases' and 'induct' methods new provide a ?case binding for
   468 the result to be shown in each case;
   469 
   470 * HOL: added 'recdef_tc' command;
   471 
   472 * isatool convert assists in eliminating legacy ML scripts;
   473 
   474 
   475 *** HOL ***
   476 
   477 * HOL/Library: a collection of generic theories to be used together
   478 with main HOL; the theory loader path already includes this directory
   479 by default; the following existing theories have been moved here:
   480 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
   481 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
   482 
   483 * HOL/Unix: "Some aspects of Unix file-system security", a typical
   484 modelling and verification task performed in Isabelle/HOL +
   485 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
   486 
   487 * HOL/Algebra: special summation operator SUM no longer exists, it has
   488 been replaced by setsum; infix 'assoc' now has priority 50 (like
   489 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
   490 'domain', this makes the theory consistent with mathematical
   491 literature;
   492 
   493 * HOL basics: added overloaded operations "inverse" and "divide"
   494 (infix "/"), syntax for generic "abs" operation, generic summation
   495 operator \<Sum>;
   496 
   497 * HOL/typedef: simplified package, provide more useful rules (see also
   498 HOL/subset.thy);
   499 
   500 * HOL/datatype: induction rule for arbitrarily branching datatypes is
   501 now expressed as a proper nested rule (old-style tactic scripts may
   502 require atomize_strip_tac to cope with non-atomic premises);
   503 
   504 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
   505 to "split_conv" (old name still available for compatibility);
   506 
   507 * HOL: improved concrete syntax for strings (e.g. allows translation
   508 rules with string literals);
   509 
   510 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
   511  and Fleuriot's mechanization of analysis, including the transcendental
   512  functions for the reals;
   513 
   514 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
   515 
   516 
   517 *** CTT ***
   518 
   519 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
   520 "lam" is displayed as TWO lambda-symbols
   521 
   522 * CTT: theory Main now available, containing everything (that is, Bool
   523 and Arith);
   524 
   525 
   526 *** General ***
   527 
   528 * Pure: the Simplifier has been implemented properly as a derived rule
   529 outside of the actual kernel (at last!); the overall performance
   530 penalty in practical applications is about 50%, while reliability of
   531 the Isabelle inference kernel has been greatly improved;
   532 
   533 * print modes "brackets" and "no_brackets" control output of nested =>
   534 (types) and ==> (props); the default behaviour is "brackets";
   535 
   536 * Provers: fast_tac (and friends) now handle actual object-logic rules
   537 as assumptions as well;
   538 
   539 * system: support Poly/ML 4.0;
   540 
   541 * system: isatool install handles KDE version 1 or 2;
   542 
   543 
   544 
   545 New in Isabelle99-1 (October 2000)
   546 ----------------------------------
   547 
   548 *** Overview of INCOMPATIBILITIES ***
   549 
   550 * HOL: simplification of natural numbers is much changed; to partly
   551 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
   552 issue the following ML commands:
   553 
   554   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
   555   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
   556 
   557 * HOL: simplification no longer dives into case-expressions; this is
   558 controlled by "t.weak_case_cong" for each datatype t;
   559 
   560 * HOL: nat_less_induct renamed to less_induct;
   561 
   562 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
   563 fixsome to patch .thy and .ML sources automatically;
   564 
   565   select_equality  -> some_equality
   566   select_eq_Ex     -> some_eq_ex
   567   selectI2EX       -> someI2_ex
   568   selectI2         -> someI2
   569   selectI          -> someI
   570   select1_equality -> some1_equality
   571   Eps_sym_eq       -> some_sym_eq_trivial
   572   Eps_eq           -> some_eq_trivial
   573 
   574 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
   575 
   576 * HOL: removed obsolete theorem binding expand_if (refer to split_if
   577 instead);
   578 
   579 * HOL: the recursion equations generated by 'recdef' are now called
   580 f.simps instead of f.rules;
   581 
   582 * HOL: qed_spec_mp now also handles bounded ALL as well;
   583 
   584 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
   585 sometimes be needed;
   586 
   587 * HOL: the constant for "f``x" is now "image" rather than "op ``";
   588 
   589 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
   590 
   591 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
   592 product is now "<*>" instead of "Times"; the lexicographic product is
   593 now "<*lex*>" instead of "**";
   594 
   595 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
   596 of main HOL, but was unused); better use HOL's datatype package;
   597 
   598 * HOL: removed "symbols" syntax for constant "override" of theory Map;
   599 the old syntax may be recovered as follows:
   600 
   601   syntax (symbols)
   602     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
   603       (infixl "\\<oplus>" 100)
   604 
   605 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   606 
   607 * HOL/ML: even fewer consts are declared as global (see theories Ord,
   608 Lfp, Gfp, WF); this only affects ML packages that refer to const names
   609 internally;
   610 
   611 * HOL and ZF: syntax for quotienting wrt an equivalence relation
   612 changed from A/r to A//r;
   613 
   614 * ZF: new treatment of arithmetic (nat & int) may break some old
   615 proofs;
   616 
   617 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
   618 rulify -> rule_format, elimify -> elim_format, ...);
   619 
   620 * Isar/Provers: intro/elim/dest attributes changed; renamed
   621 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
   622 should have to change intro!! to intro? only); replaced "delrule" by
   623 "rule del";
   624 
   625 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
   626 
   627 * Provers: strengthened force_tac by using new first_best_tac;
   628 
   629 * LaTeX document preparation: several changes of isabelle.sty (see
   630 lib/texinputs);
   631 
   632 
   633 *** Document preparation ***
   634 
   635 * formal comments (text blocks etc.) in new-style theories may now
   636 contain antiquotations of thm/prop/term/typ/text to be presented
   637 according to latex print mode; concrete syntax is like this:
   638 @{term[show_types] "f(x) = a + x"};
   639 
   640 * isatool mkdir provides easy setup of Isabelle session directories,
   641 including proper document sources;
   642 
   643 * generated LaTeX sources are now deleted after successful run
   644 (isatool document -c); may retain a copy somewhere else via -D option
   645 of isatool usedir;
   646 
   647 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
   648 style files, achieving self-contained LaTeX sources and simplifying
   649 LaTeX debugging;
   650 
   651 * old-style theories now produce (crude) LaTeX output as well;
   652 
   653 * browser info session directories are now self-contained (may be put
   654 on WWW server seperately); improved graphs of nested sessions; removed
   655 graph for 'all sessions';
   656 
   657 * several improvements in isabelle style files; \isabellestyle{it}
   658 produces fake math mode output; \isamarkupheader is now \section by
   659 default; see lib/texinputs/isabelle.sty etc.;
   660 
   661 
   662 *** Isar ***
   663 
   664 * Isar/Pure: local results and corresponding term bindings are now
   665 subject to Hindley-Milner polymorphism (similar to ML); this
   666 accommodates incremental type-inference very nicely;
   667 
   668 * Isar/Pure: new derived language element 'obtain' supports
   669 generalized existence reasoning;
   670 
   671 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
   672 support accumulation of results, without applying any rules yet;
   673 useful to collect intermediate results without explicit name
   674 references, and for use with transitivity rules with more than 2
   675 premises;
   676 
   677 * Isar/Pure: scalable support for case-analysis type proofs: new
   678 'case' language element refers to local contexts symbolically, as
   679 produced by certain proof methods; internally, case names are attached
   680 to theorems as "tags";
   681 
   682 * Isar/Pure: theory command 'hide' removes declarations from
   683 class/type/const name spaces;
   684 
   685 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
   686 indicate potential overloading;
   687 
   688 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
   689 
   690 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
   691 "{a,b,c}" instead of {a,b,c};
   692 
   693 * Isar/Pure now provides its own version of intro/elim/dest
   694 attributes; useful for building new logics, but beware of confusion
   695 with the version in Provers/classical;
   696 
   697 * Isar/Pure: the local context of (non-atomic) goals is provided via
   698 case name 'antecedent';
   699 
   700 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
   701 to the current context is now done automatically);
   702 
   703 * Isar/Pure: theory command 'method_setup' provides a simple interface
   704 for definining proof methods in ML;
   705 
   706 * Isar/Provers: intro/elim/dest attributes changed; renamed
   707 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
   708 most cases, one should have to change intro!! to intro? only);
   709 replaced "delrule" by "rule del";
   710 
   711 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
   712 'symmetric' attribute (the latter supercedes [RS sym]);
   713 
   714 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
   715 method modifier); 'simp' method: 'only:' modifier removes loopers as
   716 well (including splits);
   717 
   718 * Isar/Provers: Simplifier and Classical methods now support all kind
   719 of modifiers used in the past, including 'cong', 'iff', etc.
   720 
   721 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
   722 of Simplifier and Classical reasoner);
   723 
   724 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
   725 now support named cases; major packages (inductive, datatype, primrec,
   726 recdef) support case names and properly name parameters;
   727 
   728 * Isar/HOL: new transitivity rules for substitution in inequalities --
   729 monotonicity conditions are extracted to be proven at end of
   730 calculations;
   731 
   732 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
   733 method anyway;
   734 
   735 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
   736 split_if split_if_asm; datatype package provides theorems foo.splits =
   737 foo.split foo.split_asm for each datatype;
   738 
   739 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
   740 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
   741 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
   742 use "(cases (simplified))" method in proper proof texts);
   743 
   744 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
   745 
   746 * Isar: names of theorems etc. may be natural numbers as well;
   747 
   748 * Isar: 'pr' command: optional arguments for goals_limit and
   749 ProofContext.prems_limit; no longer prints theory contexts, but only
   750 proof states;
   751 
   752 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
   753 additional print modes to be specified; e.g. "pr(latex)" will print
   754 proof state according to the Isabelle LaTeX style;
   755 
   756 * Isar: improved support for emulating tactic scripts, including proof
   757 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
   758 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
   759 (for HOL datatypes);
   760 
   761 * Isar: simplified (more robust) goal selection of proof methods: 1st
   762 goal, all goals, or explicit goal specifier (tactic emulation); thus
   763 'proof method scripts' have to be in depth-first order;
   764 
   765 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
   766 
   767 * Isar: removed 'help' command, which hasn't been too helpful anyway;
   768 should instead use individual commands for printing items
   769 (print_commands, print_methods etc.);
   770 
   771 * Isar: added 'nothing' --- the empty list of theorems;
   772 
   773 
   774 *** HOL ***
   775 
   776 * HOL/MicroJava: formalization of a fragment of Java, together with a
   777 corresponding virtual machine and a specification of its bytecode
   778 verifier and a lightweight bytecode verifier, including proofs of
   779 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
   780 Cornelia Pusch (see also the homepage of project Bali at
   781 http://isabelle.in.tum.de/Bali/);
   782 
   783 * HOL/Algebra: new theory of rings and univariate polynomials, by
   784 Clemens Ballarin;
   785 
   786 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
   787 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
   788 Rasmussen;
   789 
   790 * HOL/Lattice: fundamental concepts of lattice theory and order
   791 structures, including duals, properties of bounds versus algebraic
   792 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
   793 Theorem for complete lattices etc.; may also serve as a demonstration
   794 for abstract algebraic reasoning using axiomatic type classes, and
   795 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
   796 
   797 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
   798 von Oheimb;
   799 
   800 * HOL/IMPP: extension of IMP with local variables and mutually
   801 recursive procedures, by David von Oheimb;
   802 
   803 * HOL/Lambda: converted into new-style theory and document;
   804 
   805 * HOL/ex/Multiquote: example of multiple nested quotations and
   806 anti-quotations -- basically a generalized version of de-Bruijn
   807 representation; very useful in avoiding lifting of operations;
   808 
   809 * HOL/record: added general record equality rule to simpset; fixed
   810 select-update simplification procedure to handle extended records as
   811 well; admit "r" as field name;
   812 
   813 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
   814 other numeric types and also as the identity of groups, rings, etc.;
   815 
   816 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
   817 Types nat and int belong to this axclass;
   818 
   819 * HOL: greatly improved simplification involving numerals of type nat, int, real:
   820    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
   821    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
   822   two terms #m*u and #n*u are replaced by #(m+n)*u
   823     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
   824   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
   825     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
   826 
   827 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
   828 powerful prover for predicate logic but knows nothing of clasets; see
   829 ex/mesontest.ML and ex/mesontest2.ML for example applications;
   830 
   831 * HOL: new version of "case_tac" subsumes both boolean case split and
   832 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
   833 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
   834 
   835 * HOL: simplification no longer dives into case-expressions: only the
   836 selector expression is simplified, but not the remaining arms; to
   837 enable full simplification of case-expressions for datatype t, you may
   838 remove t.weak_case_cong from the simpset, either globally (Delcongs
   839 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
   840 
   841 * HOL/recdef: the recursion equations generated by 'recdef' for
   842 function 'f' are now called f.simps instead of f.rules; if all
   843 termination conditions are proved automatically, these simplification
   844 rules are added to the simpset, as in primrec; rules may be named
   845 individually as well, resulting in a separate list of theorems for
   846 each equation;
   847 
   848 * HOL/While is a new theory that provides a while-combinator. It
   849 permits the definition of tail-recursive functions without the
   850 provision of a termination measure. The latter is necessary once the
   851 invariant proof rule for while is applied.
   852 
   853 * HOL: new (overloaded) notation for the set of elements below/above
   854 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
   855 
   856 * HOL: theorems impI, allI, ballI bound as "strip";
   857 
   858 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
   859 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
   860 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
   861 
   862 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   863 
   864 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
   865 main HOL, but was unused);
   866 
   867 * HOL: fewer consts declared as global (e.g. have to refer to
   868 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
   869 
   870 * HOL: tuned AST representation of nested pairs, avoiding bogus output
   871 in case of overlap with user translations (e.g. judgements over
   872 tuples); (note that the underlying logical represenation is still
   873 bogus);
   874 
   875 
   876 *** ZF ***
   877 
   878 * ZF: simplification automatically cancels common terms in arithmetic
   879 expressions over nat and int;
   880 
   881 * ZF: new treatment of nat to minimize type-checking: all operators
   882 coerce their operands to a natural number using the function natify,
   883 making the algebraic laws unconditional;
   884 
   885 * ZF: as above, for int: operators coerce their operands to an integer
   886 using the function intify;
   887 
   888 * ZF: the integer library now contains many of the usual laws for the
   889 orderings, including $<=, and monotonicity laws for $+ and $*;
   890 
   891 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
   892 simplification;
   893 
   894 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
   895 to the simplifier and classical reasoner simultaneously;
   896 
   897 
   898 *** General ***
   899 
   900 * Provers: blast_tac now handles actual object-logic rules as
   901 assumptions; note that auto_tac uses blast_tac internally as well;
   902 
   903 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
   904 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
   905 
   906 * Provers: delrules now handles destruct rules as well (no longer need
   907 explicit make_elim);
   908 
   909 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
   910   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   911 use instead the strong form,
   912   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   913 in HOL, FOL and ZF the function cla_make_elim will create such rules
   914 from destruct-rules;
   915 
   916 * Provers: Simplifier.easy_setup provides a fast path to basic
   917 Simplifier setup for new object-logics;
   918 
   919 * Pure: AST translation rules no longer require constant head on LHS;
   920 
   921 * Pure: improved name spaces: ambiguous output is qualified; support
   922 for hiding of names;
   923 
   924 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
   925 XSYMBOL_HOME; no longer need to do manual configuration in most
   926 situations;
   927 
   928 * system: compression of ML heaps images may now be controlled via -c
   929 option of isabelle and isatool usedir (currently only observed by
   930 Poly/ML);
   931 
   932 * system: isatool installfonts may handle X-Symbol fonts as well (very
   933 useful for remote X11);
   934 
   935 * system: provide TAGS file for Isabelle sources;
   936 
   937 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
   938 order;
   939 
   940 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
   941 timing flag supersedes proof_timing and Toplevel.trace;
   942 
   943 * ML: new combinators |>> and |>>> for incremental transformations
   944 with secondary results (e.g. certain theory extensions):
   945 
   946 * ML: PureThy.add_defs gets additional argument to indicate potential
   947 overloading (usually false);
   948 
   949 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
   950 results;
   951 
   952 
   953 
   954 New in Isabelle99 (October 1999)
   955 --------------------------------
   956 
   957 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   958 
   959 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
   960 are no longer simplified.  (This allows the simplifier to unfold recursive
   961 functional programs.)  To restore the old behaviour, declare
   962 
   963     Delcongs [if_weak_cong];
   964 
   965 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
   966 complement;
   967 
   968 * HOL: the predicate "inj" is now defined by translation to "inj_on";
   969 
   970 * HOL/datatype: mutual_induct_tac no longer exists --
   971   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
   972 
   973 * HOL/typedef: fixed type inference for representing set; type
   974 arguments now have to occur explicitly on the rhs as type constraints;
   975 
   976 * ZF: The con_defs part of an inductive definition may no longer refer
   977 to constants declared in the same theory;
   978 
   979 * HOL, ZF: the function mk_cases, generated by the inductive
   980 definition package, has lost an argument.  To simplify its result, it
   981 uses the default simpset instead of a supplied list of theorems.
   982 
   983 * HOL/List: the constructors of type list are now Nil and Cons;
   984 
   985 * Simplifier: the type of the infix ML functions
   986         setSSolver addSSolver setSolver addSolver
   987 is now  simpset * solver -> simpset  where `solver' is a new abstract type
   988 for packaging solvers. A solver is created via
   989         mk_solver: string -> (thm list -> int -> tactic) -> solver
   990 where the string argument is only a comment.
   991 
   992 
   993 *** Proof tools ***
   994 
   995 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
   996 decision procedure for linear arithmetic. Currently it is used for
   997 types `nat', `int', and `real' in HOL (see below); it can, should and
   998 will be instantiated for other types and logics as well.
   999 
  1000 * The simplifier now accepts rewrite rules with flexible heads, eg
  1001      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  1002   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  1003   matching.
  1004 
  1005 
  1006 *** General ***
  1007 
  1008 * New Isabelle/Isar subsystem provides an alternative to traditional
  1009 tactical theorem proving; together with the ProofGeneral/isar user
  1010 interface it offers an interactive environment for developing human
  1011 readable proof documents (Isar == Intelligible semi-automated
  1012 reasoning); for further information see isatool doc isar-ref,
  1013 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  1014 
  1015 * improved and simplified presentation of theories: better HTML markup
  1016 (including colors), graph views in several sizes; isatool usedir now
  1017 provides a proper interface for user theories (via -P option); actual
  1018 document preparation based on (PDF)LaTeX is available as well (for
  1019 new-style theories only); see isatool doc system for more information;
  1020 
  1021 * native support for Proof General, both for classic Isabelle and
  1022 Isabelle/Isar;
  1023 
  1024 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  1025 using the graph browser tool;
  1026 
  1027 * Isabelle manuals now also available as PDF;
  1028 
  1029 * theory loader rewritten from scratch (may not be fully
  1030 bug-compatible); old loadpath variable has been replaced by show_path,
  1031 add_path, del_path, reset_path functions; new operations such as
  1032 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  1033 isatool doc ref);
  1034 
  1035 * improved isatool install: option -k creates KDE application icon,
  1036 option -p DIR installs standalone binaries;
  1037 
  1038 * added ML_PLATFORM setting (useful for cross-platform installations);
  1039 more robust handling of platform specific ML images for SML/NJ;
  1040 
  1041 * the settings environment is now statically scoped, i.e. it is never
  1042 created again in sub-processes invoked from isabelle, isatool, or
  1043 Isabelle;
  1044 
  1045 * path element specification '~~' refers to '$ISABELLE_HOME';
  1046 
  1047 * in locales, the "assumes" and "defines" parts may be omitted if
  1048 empty;
  1049 
  1050 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  1051 long arrows);
  1052 
  1053 * new print_mode "HTML";
  1054 
  1055 * new flag show_tags controls display of tags of theorems (which are
  1056 basically just comments that may be attached by some tools);
  1057 
  1058 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  1059 mode and goal output format:
  1060 
  1061 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  1062 244c244
  1063 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  1064 ---
  1065 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  1066 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  1067 181c181
  1068 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  1069 ---
  1070 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  1071 
  1072 * function bind_thms stores lists of theorems (cf. bind_thm);
  1073 
  1074 * new shorthand tactics ftac, eatac, datac, fatac;
  1075 
  1076 * qed (and friends) now accept "" as result name; in that case the
  1077 theorem is not stored, but proper checks and presentation of the
  1078 result still apply;
  1079 
  1080 * theorem database now also indexes constants "Trueprop", "all",
  1081 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  1082 
  1083 
  1084 *** HOL ***
  1085 
  1086 ** HOL arithmetic **
  1087 
  1088 * There are now decision procedures for linear arithmetic over nat and
  1089 int:
  1090 
  1091 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  1092 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  1093 are treated as atomic; subformulae not involving type `nat' or `int'
  1094 are ignored; quantified subformulae are ignored unless they are
  1095 positive universal or negative existential. The tactic has to be
  1096 invoked by hand and can be a little bit slow. In particular, the
  1097 running time is exponential in the number of occurrences of `min' and
  1098 `max', and `-' on `nat'.
  1099 
  1100 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  1101 (negated) (in)equalities among the premises and the conclusion into
  1102 account (i.e. no compound formulae) and does not know about `min' and
  1103 `max', and `-' on `nat'. It is fast and is used automatically by the
  1104 simplifier.
  1105 
  1106 NB: At the moment, these decision procedures do not cope with mixed
  1107 nat/int formulae where the two parts interact, such as `m < n ==>
  1108 int(m) < int(n)'.
  1109 
  1110 * HOL/Numeral provides a generic theory of numerals (encoded
  1111 efficiently as bit strings); setup for types nat/int/real is in place;
  1112 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  1113 int, existing theories and proof scripts may require a few additional
  1114 type constraints;
  1115 
  1116 * integer division and remainder can now be performed on constant
  1117 arguments;
  1118 
  1119 * many properties of integer multiplication, division and remainder
  1120 are now available;
  1121 
  1122 * An interface to the Stanford Validity Checker (SVC) is available through the
  1123 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  1124 are proved automatically.  SVC must be installed separately, and its results
  1125 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  1126 invocation of the underlying oracle).  For SVC see
  1127   http://verify.stanford.edu/SVC
  1128 
  1129 * IsaMakefile: the HOL-Real target now builds an actual image;
  1130 
  1131 
  1132 ** HOL misc **
  1133 
  1134 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  1135 (in Isabelle/Isar) -- by Gertrud Bauer;
  1136 
  1137 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  1138 analysis for assembly languages with subtypes;
  1139 
  1140 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  1141 -- avoids syntactic ambiguities and treats state, transition, and
  1142 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  1143 changed syntax and (many) tactics;
  1144 
  1145 * HOL/inductive: Now also handles more general introduction rules such
  1146   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  1147   theorems are now maintained within the theory (maintained via the
  1148   "mono" attribute);
  1149 
  1150 * HOL/datatype: Now also handles arbitrarily branching datatypes
  1151   (using function types) such as
  1152 
  1153   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  1154 
  1155 * HOL/record: record_simproc (part of the default simpset) takes care
  1156 of selectors applied to updated records; record_split_tac is no longer
  1157 part of the default claset; update_defs may now be removed from the
  1158 simpset in many cases; COMPATIBILITY: old behavior achieved by
  1159 
  1160   claset_ref () := claset() addSWrapper record_split_wrapper;
  1161   Delsimprocs [record_simproc]
  1162 
  1163 * HOL/typedef: fixed type inference for representing set; type
  1164 arguments now have to occur explicitly on the rhs as type constraints;
  1165 
  1166 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  1167 names rather than an ML expression;
  1168 
  1169 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  1170 supplied later.  Program schemes can be defined, such as
  1171     "While B C s = (if B s then While B C (C s) else s)"
  1172 where the well-founded relation can be chosen after B and C have been given.
  1173 
  1174 * HOL/List: the constructors of type list are now Nil and Cons;
  1175 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  1176 course, ML tools referring to List.list.op # etc. have to be adapted;
  1177 
  1178 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  1179 disabled by default; run isabelle with option -m HOL to get back to
  1180 the original Gordon/HOL-style output;
  1181 
  1182 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  1183 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  1184 
  1185 * HOL basic syntax simplified (more orthogonal): all variants of
  1186 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  1187 Eps operator is provided as well: "SOME x. P[x]";
  1188 
  1189 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  1190 
  1191 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  1192 thus available for user theories;
  1193 
  1194 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  1195 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  1196 time;
  1197 
  1198 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  1199 several times and then mp;
  1200 
  1201 
  1202 *** LK ***
  1203 
  1204 * the notation <<...>> is now available as a notation for sequences of
  1205 formulas;
  1206 
  1207 * the simplifier is now installed
  1208 
  1209 * the axiom system has been generalized (thanks to Soren Heilmann)
  1210 
  1211 * the classical reasoner now has a default rule database
  1212 
  1213 
  1214 *** ZF ***
  1215 
  1216 * new primrec section allows primitive recursive functions to be given
  1217 directly (as in HOL) over datatypes and the natural numbers;
  1218 
  1219 * new tactics induct_tac and exhaust_tac for induction (or case
  1220 analysis) over datatypes and the natural numbers;
  1221 
  1222 * the datatype declaration of type T now defines the recursor T_rec;
  1223 
  1224 * simplification automatically does freeness reasoning for datatype
  1225 constructors;
  1226 
  1227 * automatic type-inference, with AddTCs command to insert new
  1228 type-checking rules;
  1229 
  1230 * datatype introduction rules are now added as Safe Introduction rules
  1231 to the claset;
  1232 
  1233 * the syntax "if P then x else y" is now available in addition to
  1234 if(P,x,y);
  1235 
  1236 
  1237 *** Internal programming interfaces ***
  1238 
  1239 * tuned simplifier trace output; new flag debug_simp;
  1240 
  1241 * structures Vartab / Termtab (instances of TableFun) offer efficient
  1242 tables indexed by indexname_ord / term_ord (compatible with aconv);
  1243 
  1244 * AxClass.axclass_tac lost the theory argument;
  1245 
  1246 * tuned current_goals_markers semantics: begin / end goal avoids
  1247 printing empty lines;
  1248 
  1249 * removed prs and prs_fn hook, which was broken because it did not
  1250 include \n in its semantics, forcing writeln to add one
  1251 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  1252 string -> unit if you really want to output text without newline;
  1253 
  1254 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  1255 plain output, interface builders may have to enable 'isabelle_font'
  1256 mode to get Isabelle font glyphs as before;
  1257 
  1258 * refined token_translation interface; INCOMPATIBILITY: output length
  1259 now of type real instead of int;
  1260 
  1261 * theory loader actions may be traced via new ThyInfo.add_hook
  1262 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  1263 your own database of information attached to *whole* theories -- as
  1264 opposed to intra-theory data slots offered via TheoryDataFun;
  1265 
  1266 * proper handling of dangling sort hypotheses (at last!);
  1267 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  1268 extra sort hypotheses that can be witnessed from the type signature;
  1269 the force_strip_shyps flag is gone, any remaining shyps are simply
  1270 left in the theorem (with a warning issued by strip_shyps_warning);
  1271 
  1272 
  1273 
  1274 New in Isabelle98-1 (October 1998)
  1275 ----------------------------------
  1276 
  1277 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1278 
  1279 * several changes of automated proof tools;
  1280 
  1281 * HOL: major changes to the inductive and datatype packages, including
  1282 some minor incompatibilities of theory syntax;
  1283 
  1284 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  1285 called `inj_on';
  1286 
  1287 * HOL: removed duplicate thms in Arith:
  1288   less_imp_add_less  should be replaced by  trans_less_add1
  1289   le_imp_add_le      should be replaced by  trans_le_add1
  1290 
  1291 * HOL: unary minus is now overloaded (new type constraints may be
  1292 required);
  1293 
  1294 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  1295 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  1296 now taken as an integer constant.
  1297 
  1298 * Pure: ML function 'theory_of' renamed to 'theory';
  1299 
  1300 
  1301 *** Proof tools ***
  1302 
  1303 * Simplifier:
  1304   1. Asm_full_simp_tac is now more aggressive.
  1305      1. It will sometimes reorient premises if that increases their power to
  1306         simplify.
  1307      2. It does no longer proceed strictly from left to right but may also
  1308         rotate premises to achieve further simplification.
  1309      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  1310      old Asm_full_simp_tac in that it does not rotate premises.
  1311   2. The simplifier now knows a little bit about nat-arithmetic.
  1312 
  1313 * Classical reasoner: wrapper mechanism for the classical reasoner now
  1314 allows for selected deletion of wrappers, by introduction of names for
  1315 wrapper functionals.  This implies that addbefore, addSbefore,
  1316 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  1317 and that adding two tactics with the same name overwrites the first
  1318 one (emitting a warning).
  1319   type wrapper = (int -> tactic) -> (int -> tactic)
  1320   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  1321   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  1322   delWrapper, delSWrapper: claset *  string            -> claset
  1323   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  1324 
  1325 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  1326 semantics; addbefore now affects only the unsafe part of step_tac
  1327 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  1328 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  1329 by Force_tac;
  1330 
  1331 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  1332 compWrapper; added safe wrapper (and access functions for it);
  1333 
  1334 * HOL/split_all_tac is now much faster and fails if there is nothing
  1335 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  1336 and the names of the automatically generated variables have changed.
  1337 split_all_tac has moved within claset() from unsafe wrappers to safe
  1338 wrappers, which means that !!-bound variables are split much more
  1339 aggressively, and safe_tac and clarify_tac now split such variables.
  1340 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  1341 Note: the same holds for record_split_tac, which does the job of
  1342 split_all_tac for record fields.
  1343 
  1344 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  1345 permanently to the default simpset using Addsplits just like
  1346 Addsimps. They can be removed via Delsplits just like
  1347 Delsimps. Lower-case versions are also available.
  1348 
  1349 * HOL/Simplifier: The rule split_if is now part of the default
  1350 simpset. This means that the simplifier will eliminate all occurrences
  1351 of if-then-else in the conclusion of a goal. To prevent this, you can
  1352 either remove split_if completely from the default simpset by
  1353 `Delsplits [split_if]' or remove it in a specific call of the
  1354 simplifier using `... delsplits [split_if]'.  You can also add/delete
  1355 other case splitting rules to/from the default simpset: every datatype
  1356 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  1357 t is the name of the datatype).
  1358 
  1359 * Classical reasoner / Simplifier combination: new force_tac (and
  1360 derivatives Force_tac, force) combines rewriting and classical
  1361 reasoning (and whatever other tools) similarly to auto_tac, but is
  1362 aimed to solve the given subgoal completely.
  1363 
  1364 
  1365 *** General ***
  1366 
  1367 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  1368 and `goalw': the theory is no longer needed as an explicit argument -
  1369 the current theory context is used; assumptions are no longer returned
  1370 at the ML-level unless one of them starts with ==> or !!; it is
  1371 recommended to convert to these new commands using isatool fixgoal
  1372 (backup your sources first!);
  1373 
  1374 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  1375 the current theory context, and 'theory' to lookup stored theories;
  1376 
  1377 * new theory section 'locale' for declaring constants, assumptions and
  1378 definitions that have local scope;
  1379 
  1380 * new theory section 'nonterminals' for purely syntactic types;
  1381 
  1382 * new theory section 'setup' for generic ML setup functions
  1383 (e.g. package initialization);
  1384 
  1385 * the distribution now includes Isabelle icons: see
  1386 lib/logo/isabelle-{small,tiny}.xpm;
  1387 
  1388 * isatool install - install binaries with absolute references to
  1389 ISABELLE_HOME/bin;
  1390 
  1391 * isatool logo -- create instances of the Isabelle logo (as EPS);
  1392 
  1393 * print mode 'emacs' reserved for Isamode;
  1394 
  1395 * support multiple print (ast) translations per constant name;
  1396 
  1397 * theorems involving oracles are now printed with a suffixed [!];
  1398 
  1399 
  1400 *** HOL ***
  1401 
  1402 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  1403 
  1404 * HOL/inductive package reorganized and improved: now supports mutual
  1405 definitions such as
  1406 
  1407   inductive EVEN ODD
  1408     intrs
  1409       null "0 : EVEN"
  1410       oddI "n : EVEN ==> Suc n : ODD"
  1411       evenI "n : ODD ==> Suc n : EVEN"
  1412 
  1413 new theorem list "elims" contains an elimination rule for each of the
  1414 recursive sets; inductive definitions now handle disjunctive premises
  1415 correctly (also ZF);
  1416 
  1417 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  1418 "mutual_induct" no longer exists - the induction rule is always
  1419 contained in "induct";
  1420 
  1421 
  1422 * HOL/datatype package re-implemented and greatly improved: now
  1423 supports mutually recursive datatypes such as
  1424 
  1425   datatype
  1426     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  1427             | SUM ('a aexp) ('a aexp)
  1428             | DIFF ('a aexp) ('a aexp)
  1429             | NUM 'a
  1430   and
  1431     'a bexp = LESS ('a aexp) ('a aexp)
  1432             | AND ('a bexp) ('a bexp)
  1433             | OR ('a bexp) ('a bexp)
  1434 
  1435 as well as indirectly recursive datatypes such as
  1436 
  1437   datatype
  1438     ('a, 'b) term = Var 'a
  1439                   | App 'b ((('a, 'b) term) list)
  1440 
  1441 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  1442 induction on mutually / indirectly recursive datatypes.
  1443 
  1444 Primrec equations are now stored in theory and can be accessed via
  1445 <function_name>.simps.
  1446 
  1447 INCOMPATIBILITIES:
  1448 
  1449   - Theories using datatypes must now have theory Datatype as an
  1450     ancestor.
  1451   - The specific <typename>.induct_tac no longer exists - use the
  1452     generic induct_tac instead.
  1453   - natE has been renamed to nat.exhaust - use exhaust_tac
  1454     instead of res_inst_tac ... natE. Note that the variable
  1455     names in nat.exhaust differ from the names in natE, this
  1456     may cause some "fragile" proofs to fail.
  1457   - The theorems split_<typename>_case and split_<typename>_case_asm
  1458     have been renamed to <typename>.split and <typename>.split_asm.
  1459   - Since default sorts of type variables are now handled correctly,
  1460     some datatype definitions may have to be annotated with explicit
  1461     sort constraints.
  1462   - Primrec definitions no longer require function name and type
  1463     of recursive argument.
  1464 
  1465 Consider using isatool fixdatatype to adapt your theories and proof
  1466 scripts to the new package (backup your sources first!).
  1467 
  1468 
  1469 * HOL/record package: considerably improved implementation; now
  1470 includes concrete syntax for record types, terms, updates; theorems
  1471 for surjective pairing and splitting !!-bound record variables; proof
  1472 support is as follows:
  1473 
  1474   1) standard conversions (selectors or updates applied to record
  1475 constructor terms) are part of the standard simpset;
  1476 
  1477   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  1478 made part of standard simpset and claset via addIffs;
  1479 
  1480   3) a tactic for record field splitting (record_split_tac) is part of
  1481 the standard claset (addSWrapper);
  1482 
  1483 To get a better idea about these rules you may retrieve them via
  1484 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  1485 the name of your record type.
  1486 
  1487 The split tactic 3) conceptually simplifies by the following rule:
  1488 
  1489   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  1490 
  1491 Thus any record variable that is bound by meta-all will automatically
  1492 blow up into some record constructor term, consequently the
  1493 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  1494 solve record problems automatically.
  1495 
  1496 
  1497 * reorganized the main HOL image: HOL/Integ and String loaded by
  1498 default; theory Main includes everything;
  1499 
  1500 * automatic simplification of integer sums and comparisons, using cancellation;
  1501 
  1502 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  1503 
  1504 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  1505 
  1506 * many new identities for unions, intersections, set difference, etc.;
  1507 
  1508 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  1509 called split_if, split_split, split_sum_case and split_nat_case (to go
  1510 with add/delsplits);
  1511 
  1512 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  1513 (?x::unit) = (); this is made part of the default simpset, which COULD
  1514 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  1515 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  1516 unit_abs_eta_conv is added in order to counter the effect of
  1517 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  1518 %u.f();
  1519 
  1520 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  1521 makes more sense);
  1522 
  1523 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1524   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1525   disjointness reasoning but breaking a few old proofs.
  1526 
  1527 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  1528 to 'converse' from 'inverse' (for compatibility with ZF and some
  1529 literature);
  1530 
  1531 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  1532 the well-founded relation;
  1533 
  1534 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  1535     Compl A.  The "Compl" syntax remains available as input syntax for this
  1536     release ONLY.
  1537 
  1538 * HOL/Update: new theory of function updates:
  1539     f(a:=b) == %x. if x=a then b else f x
  1540 may also be iterated as in f(a:=b,c:=d,...);
  1541 
  1542 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  1543 
  1544 * HOL/List:
  1545   - new function list_update written xs[i:=v] that updates the i-th
  1546     list position. May also be iterated as in xs[i:=a,j:=b,...].
  1547   - new function `upt' written [i..j(] which generates the list
  1548     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  1549     bound write [i..j], which is a shorthand for [i..j+1(].
  1550   - new lexicographic orderings and corresponding wellfoundedness theorems.
  1551 
  1552 * HOL/Arith:
  1553   - removed 'pred' (predecessor) function;
  1554   - generalized some theorems about n-1;
  1555   - many new laws about "div" and "mod";
  1556   - new laws about greatest common divisors (see theory ex/Primes);
  1557 
  1558 * HOL/Relation: renamed the relational operator r^-1 "converse"
  1559 instead of "inverse";
  1560 
  1561 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  1562   of the multiset ordering;
  1563 
  1564 * directory HOL/Real: a construction of the reals using Dedekind cuts
  1565   (not included by default);
  1566 
  1567 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  1568 
  1569 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  1570   programs, i.e. different program variables may have different types.
  1571 
  1572 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1573   [previously, this check worked only if the rewrite rule was unconditional]
  1574   Now rew can involve either definitions or equalities (either == or =).
  1575 
  1576 
  1577 *** ZF ***
  1578 
  1579 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  1580   only the theorems proved on ZF.ML;
  1581 
  1582 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1583   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1584   disjointness reasoning but breaking a few old proofs.
  1585 
  1586 * ZF/Update: new theory of function updates
  1587     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  1588   may also be iterated as in f(a:=b,c:=d,...);
  1589 
  1590 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  1591 
  1592 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1593   [previously, this check worked only if the rewrite rule was unconditional]
  1594   Now rew can involve either definitions or equalities (either == or =).
  1595 
  1596 * case_tac provided for compatibility with HOL
  1597     (like the old excluded_middle_tac, but with subgoals swapped)
  1598 
  1599 
  1600 *** Internal programming interfaces ***
  1601 
  1602 * Pure: several new basic modules made available for general use, see
  1603 also src/Pure/README;
  1604 
  1605 * improved the theory data mechanism to support encapsulation (data
  1606 kind name replaced by private Object.kind, acting as authorization
  1607 key); new type-safe user interface via functor TheoryDataFun; generic
  1608 print_data function becomes basically useless;
  1609 
  1610 * removed global_names compatibility flag -- all theory declarations
  1611 are qualified by default;
  1612 
  1613 * module Pure/Syntax now offers quote / antiquote translation
  1614 functions (useful for Hoare logic etc. with implicit dependencies);
  1615 see HOL/ex/Antiquote for an example use;
  1616 
  1617 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  1618 cterm -> thm;
  1619 
  1620 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  1621 subgoal;
  1622 
  1623 * Display.print_goals function moved to Locale.print_goals;
  1624 
  1625 * standard print function for goals supports current_goals_markers
  1626 variable for marking begin of proof, end of proof, start of goal; the
  1627 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  1628 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  1629 for example;
  1630 
  1631 
  1632 
  1633 New in Isabelle98 (January 1998)
  1634 --------------------------------
  1635 
  1636 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1637 
  1638 * changed lexical syntax of terms / types: dots made part of long
  1639 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  1640 
  1641 * simpset (and claset) reference variable replaced by functions
  1642 simpset / simpset_ref;
  1643 
  1644 * no longer supports theory aliases (via merge) and non-trivial
  1645 implicit merge of thms' signatures;
  1646 
  1647 * most internal names of constants changed due to qualified names;
  1648 
  1649 * changed Pure/Sequence interface (see Pure/seq.ML);
  1650 
  1651 
  1652 *** General Changes ***
  1653 
  1654 * hierachically structured name spaces (for consts, types, axms, thms
  1655 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  1656 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  1657 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  1658 long_names for fully qualified output names; NOTE: ML programs
  1659 (special tactics, packages etc.) referring to internal names may have
  1660 to be adapted to cope with fully qualified names; in case of severe
  1661 backward campatibility problems try setting 'global_names' at compile
  1662 time to have enrything declared within a flat name space; one may also
  1663 fine tune name declarations in theories via the 'global' and 'local'
  1664 section;
  1665 
  1666 * reimplemented the implicit simpset and claset using the new anytype
  1667 data filed in signatures; references simpset:simpset ref etc. are
  1668 replaced by functions simpset:unit->simpset and
  1669 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  1670 to patch your ML files accordingly;
  1671 
  1672 * HTML output now includes theory graph data for display with Java
  1673 applet or isatool browser; data generated automatically via isatool
  1674 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  1675 
  1676 * defs may now be conditional; improved rewrite_goals_tac to handle
  1677 conditional equations;
  1678 
  1679 * defs now admits additional type arguments, using TYPE('a) syntax;
  1680 
  1681 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  1682 creates a new theory node; implicit merge of thms' signatures is
  1683 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  1684 transfer:theory->thm->thm in (rare) cases;
  1685 
  1686 * improved handling of draft signatures / theories; draft thms (and
  1687 ctyps, cterms) are automatically promoted to real ones;
  1688 
  1689 * slightly changed interfaces for oracles: admit many per theory, named
  1690 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  1691 
  1692 * print_goals: optional output of const types (set show_consts and
  1693 show_types);
  1694 
  1695 * improved output of warnings (###) and errors (***);
  1696 
  1697 * subgoal_tac displays a warning if the new subgoal has type variables;
  1698 
  1699 * removed old README and Makefiles;
  1700 
  1701 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  1702 
  1703 * removed obsolete init_pps and init_database;
  1704 
  1705 * deleted the obsolete tactical STATE, which was declared by
  1706     fun STATE tacfun st = tacfun st st;
  1707 
  1708 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  1709 (which abbreviates $HOME);
  1710 
  1711 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  1712 use isatool fixseq to adapt your ML programs (this works for fully
  1713 qualified references to the Sequence structure only!);
  1714 
  1715 * use_thy no longer requires writable current directory; it always
  1716 reloads .ML *and* .thy file, if either one is out of date;
  1717 
  1718 
  1719 *** Classical Reasoner ***
  1720 
  1721 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  1722 tactics that use classical reasoning to simplify a subgoal without
  1723 splitting it into several subgoals;
  1724 
  1725 * Safe_tac: like safe_tac but uses the default claset;
  1726 
  1727 
  1728 *** Simplifier ***
  1729 
  1730 * added simplification meta rules:
  1731     (asm_)(full_)simplify: simpset -> thm -> thm;
  1732 
  1733 * simplifier.ML no longer part of Pure -- has to be loaded by object
  1734 logics (again);
  1735 
  1736 * added prems argument to simplification procedures;
  1737 
  1738 * HOL, FOL, ZF: added infix function `addsplits':
  1739   instead of `<simpset> setloop (split_tac <thms>)'
  1740   you can simply write `<simpset> addsplits <thms>'
  1741 
  1742 
  1743 *** Syntax ***
  1744 
  1745 * TYPE('a) syntax for type reflection terms;
  1746 
  1747 * no longer handles consts with name "" -- declare as 'syntax' instead;
  1748 
  1749 * pretty printer: changed order of mixfix annotation preference (again!);
  1750 
  1751 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  1752 
  1753 
  1754 *** HOL ***
  1755 
  1756 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1757   with `addloop' of the simplifier to faciliate case splitting in premises.
  1758 
  1759 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  1760 
  1761 * HOL/Auth: new protocol proofs including some for the Internet
  1762   protocol TLS;
  1763 
  1764 * HOL/Map: new theory of `maps' a la VDM;
  1765 
  1766 * HOL/simplifier: simplification procedures nat_cancel_sums for
  1767 cancelling out common nat summands from =, <, <= (in)equalities, or
  1768 differences; simplification procedures nat_cancel_factor for
  1769 cancelling common factor from =, <, <= (in)equalities over natural
  1770 sums; nat_cancel contains both kinds of procedures, it is installed by
  1771 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  1772 
  1773 * HOL/simplifier: terms of the form
  1774   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  1775   are rewritten to
  1776   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  1777   and those of the form
  1778   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  1779   are rewritten to
  1780   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  1781 
  1782 * HOL/datatype
  1783   Each datatype `t' now comes with a theorem `split_t_case' of the form
  1784 
  1785   P(t_case f1 ... fn x) =
  1786      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  1787         ...
  1788        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  1789      )
  1790 
  1791   and a theorem `split_t_case_asm' of the form
  1792 
  1793   P(t_case f1 ... fn x) =
  1794     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  1795         ...
  1796        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  1797      )
  1798   which can be added to a simpset via `addsplits'. The existing theorems
  1799   expand_list_case and expand_option_case have been renamed to
  1800   split_list_case and split_option_case.
  1801 
  1802 * HOL/Arithmetic:
  1803   - `pred n' is automatically converted to `n-1'.
  1804     Users are strongly encouraged not to use `pred' any longer,
  1805     because it will disappear altogether at some point.
  1806   - Users are strongly encouraged to write "0 < n" rather than
  1807     "n ~= 0". Theorems and proof tools have been modified towards this
  1808     `standard'.
  1809 
  1810 * HOL/Lists:
  1811   the function "set_of_list" has been renamed "set" (and its theorems too);
  1812   the function "nth" now takes its arguments in the reverse order and
  1813   has acquired the infix notation "!" as in "xs!n".
  1814 
  1815 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  1816 
  1817 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  1818   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  1819 
  1820 * HOL/record: extensible records with schematic structural subtyping
  1821 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  1822 still lacks various theorems and concrete record syntax;
  1823 
  1824 
  1825 *** HOLCF ***
  1826 
  1827 * removed "axioms" and "generated by" sections;
  1828 
  1829 * replaced "ops" section by extended "consts" section, which is capable of
  1830   handling the continuous function space "->" directly;
  1831 
  1832 * domain package:
  1833   . proves theorems immediately and stores them in the theory,
  1834   . creates hierachical name space,
  1835   . now uses normal mixfix annotations (instead of cinfix...),
  1836   . minor changes to some names and values (for consistency),
  1837   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  1838   . separator between mutual domain defs: changed "," to "and",
  1839   . improved handling of sort constraints;  now they have to
  1840     appear on the left-hand side of the equations only;
  1841 
  1842 * fixed LAM <x,y,zs>.b syntax;
  1843 
  1844 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  1845 adm (%x. P (t x)), where P is chainfinite and t continuous;
  1846 
  1847 
  1848 *** FOL and ZF ***
  1849 
  1850 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1851   with `addloop' of the simplifier to faciliate case splitting in premises.
  1852 
  1853 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  1854 in HOL, they strip ALL and --> from proved theorems;
  1855 
  1856 
  1857 
  1858 New in Isabelle94-8 (May 1997)
  1859 ------------------------------
  1860 
  1861 *** General Changes ***
  1862 
  1863 * new utilities to build / run / maintain Isabelle etc. (in parts
  1864 still somewhat experimental); old Makefiles etc. still functional;
  1865 
  1866 * new 'Isabelle System Manual';
  1867 
  1868 * INSTALL text, together with ./configure and ./build scripts;
  1869 
  1870 * reimplemented type inference for greater efficiency, better error
  1871 messages and clean internal interface;
  1872 
  1873 * prlim command for dealing with lots of subgoals (an easier way of
  1874 setting goals_limit);
  1875 
  1876 
  1877 *** Syntax ***
  1878 
  1879 * supports alternative (named) syntax tables (parser and pretty
  1880 printer); internal interface is provided by add_modesyntax(_i);
  1881 
  1882 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  1883 be used in conjunction with the Isabelle symbol font; uses the
  1884 "symbols" syntax table;
  1885 
  1886 * added token_translation interface (may translate name tokens in
  1887 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  1888 the current print_mode); IMPORTANT: user print translation functions
  1889 are responsible for marking newly introduced bounds
  1890 (Syntax.mark_boundT);
  1891 
  1892 * token translations for modes "xterm" and "xterm_color" that display
  1893 names in bold, underline etc. or colors (which requires a color
  1894 version of xterm);
  1895 
  1896 * infixes may now be declared with names independent of their syntax;
  1897 
  1898 * added typed_print_translation (like print_translation, but may
  1899 access type of constant);
  1900 
  1901 
  1902 *** Classical Reasoner ***
  1903 
  1904 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  1905 some limitations.  Blast_tac...
  1906   + ignores addss, addbefore, addafter; this restriction is intrinsic
  1907   + ignores elimination rules that don't have the correct format
  1908         (the conclusion MUST be a formula variable)
  1909   + ignores types, which can make HOL proofs fail
  1910   + rules must not require higher-order unification, e.g. apply_type in ZF
  1911     [message "Function Var's argument not a bound variable" relates to this]
  1912   + its proof strategy is more general but can actually be slower
  1913 
  1914 * substitution with equality assumptions no longer permutes other
  1915 assumptions;
  1916 
  1917 * minor changes in semantics of addafter (now called addaltern); renamed
  1918 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  1919 (and access functions for it);
  1920 
  1921 * improved combination of classical reasoner and simplifier:
  1922   + functions for handling clasimpsets
  1923   + improvement of addss: now the simplifier is called _after_ the
  1924     safe steps.
  1925   + safe variant of addss called addSss: uses safe simplifications
  1926     _during_ the safe steps. It is more complete as it allows multiple
  1927     instantiations of unknowns (e.g. with slow_tac).
  1928 
  1929 *** Simplifier ***
  1930 
  1931 * added interface for simplification procedures (functions that
  1932 produce *proven* rewrite rules on the fly, depending on current
  1933 redex);
  1934 
  1935 * ordering on terms as parameter (used for ordered rewriting);
  1936 
  1937 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  1938 
  1939 * the solver is now split into a safe and an unsafe part.
  1940 This should be invisible for the normal user, except that the
  1941 functions setsolver and addsolver have been renamed to setSolver and
  1942 addSolver; added safe_asm_full_simp_tac;
  1943 
  1944 
  1945 *** HOL ***
  1946 
  1947 * a generic induction tactic `induct_tac' which works for all datatypes and
  1948 also for type `nat';
  1949 
  1950 * a generic case distinction tactic `exhaust_tac' which works for all
  1951 datatypes and also for type `nat';
  1952 
  1953 * each datatype comes with a function `size';
  1954 
  1955 * patterns in case expressions allow tuple patterns as arguments to
  1956 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  1957 
  1958 * primrec now also works with type nat;
  1959 
  1960 * recdef: a new declaration form, allows general recursive functions to be
  1961 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  1962 
  1963 * the constant for negation has been renamed from "not" to "Not" to
  1964 harmonize with FOL, ZF, LK, etc.;
  1965 
  1966 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  1967 infinite lists;
  1968 
  1969 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  1970 
  1971 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  1972 problems in commutative rings, using axiomatic type classes for + and *;
  1973 
  1974 * more examples in HOL/MiniML and HOL/Auth;
  1975 
  1976 * more default rewrite rules for quantifiers, union/intersection;
  1977 
  1978 * a new constant `arbitrary == @x.False';
  1979 
  1980 * HOLCF/IOA replaces old HOL/IOA;
  1981 
  1982 * HOLCF changes: derived all rules and arities
  1983   + axiomatic type classes instead of classes
  1984   + typedef instead of faking type definitions
  1985   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  1986   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  1987   + eliminated the types void, one, tr
  1988   + use unit lift and bool lift (with translations) instead of one and tr
  1989   + eliminated blift from Lift3.thy (use Def instead of blift)
  1990   all eliminated rules are derived as theorems --> no visible changes ;
  1991 
  1992 
  1993 *** ZF ***
  1994 
  1995 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  1996 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  1997 as ZF_cs addSIs [equalityI];
  1998 
  1999 
  2000 
  2001 New in Isabelle94-7 (November 96)
  2002 ---------------------------------
  2003 
  2004 * allowing negative levels (as offsets) in prlev and choplev;
  2005 
  2006 * super-linear speedup for large simplifications;
  2007 
  2008 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  2009 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  2010 FAIL); can suppress it using the command Delsimps (ex_simps @
  2011 all_simps); De Morgan laws are also now included, by default;
  2012 
  2013 * improved printing of ==>  :  ~:
  2014 
  2015 * new object-logic "Sequents" adds linear logic, while replacing LK
  2016 and Modal (thanks to Sara Kalvala);
  2017 
  2018 * HOL/Auth: correctness proofs for authentication protocols;
  2019 
  2020 * HOL: new auto_tac combines rewriting and classical reasoning (many
  2021 examples on HOL/Auth);
  2022 
  2023 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  2024 the rewriter and classical reasoner simultaneously;
  2025 
  2026 * function uresult no longer returns theorems in "standard" format;
  2027 regain previous version by: val uresult = standard o uresult;
  2028 
  2029 
  2030 
  2031 New in Isabelle94-6
  2032 -------------------
  2033 
  2034 * oracles -- these establish an interface between Isabelle and trusted
  2035 external reasoners, which may deliver results as theorems;
  2036 
  2037 * proof objects (in particular record all uses of oracles);
  2038 
  2039 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  2040 
  2041 * "constdefs" section in theory files;
  2042 
  2043 * "primrec" section (HOL) no longer requires names;
  2044 
  2045 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  2046 
  2047 
  2048 
  2049 New in Isabelle94-5
  2050 -------------------
  2051 
  2052 * reduced space requirements;
  2053 
  2054 * automatic HTML generation from theories;
  2055 
  2056 * theory files no longer require "..." (quotes) around most types;
  2057 
  2058 * new examples, including two proofs of the Church-Rosser theorem;
  2059 
  2060 * non-curried (1994) version of HOL is no longer distributed;
  2061 
  2062 
  2063 
  2064 New in Isabelle94-4
  2065 -------------------
  2066 
  2067 * greatly reduced space requirements;
  2068 
  2069 * theory files (.thy) no longer require \...\ escapes at line breaks;
  2070 
  2071 * searchable theorem database (see the section "Retrieving theorems" on
  2072 page 8 of the Reference Manual);
  2073 
  2074 * new examples, including Grabczewski's monumental case study of the
  2075 Axiom of Choice;
  2076 
  2077 * The previous version of HOL renamed to Old_HOL;
  2078 
  2079 * The new version of HOL (previously called CHOL) uses a curried syntax
  2080 for functions.  Application looks like f a b instead of f(a,b);
  2081 
  2082 * Mutually recursive inductive definitions finally work in HOL;
  2083 
  2084 * In ZF, pattern-matching on tuples is now available in all abstractions and
  2085 translates to the operator "split";
  2086 
  2087 
  2088 
  2089 New in Isabelle94-3
  2090 -------------------
  2091 
  2092 * new infix operator, addss, allowing the classical reasoner to
  2093 perform simplification at each step of its search.  Example:
  2094         fast_tac (cs addss ss)
  2095 
  2096 * a new logic, CHOL, the same as HOL, but with a curried syntax
  2097 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  2098 look like (a,b) instead of <a,b>;
  2099 
  2100 * PLEASE NOTE: CHOL will eventually replace HOL!
  2101 
  2102 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  2103 It translates to the operator "split".  A new theory of integers is available;
  2104 
  2105 * In ZF, integer numerals now denote two's-complement binary integers.
  2106 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  2107 
  2108 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  2109 of the Axiom of Choice;
  2110 
  2111 
  2112 
  2113 New in Isabelle94-2
  2114 -------------------
  2115 
  2116 * Significantly faster resolution;
  2117 
  2118 * the different sections in a .thy file can now be mixed and repeated
  2119 freely;
  2120 
  2121 * Database of theorems for FOL, HOL and ZF.  New
  2122 commands including qed, qed_goal and bind_thm store theorems in the database.
  2123 
  2124 * Simple database queries: return a named theorem (get_thm) or all theorems of
  2125 a given theory (thms_of), or find out what theory a theorem was proved in
  2126 (theory_of_thm);
  2127 
  2128 * Bugs fixed in the inductive definition and datatype packages;
  2129 
  2130 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  2131 and HOL_dup_cs obsolete;
  2132 
  2133 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  2134 have been removed;
  2135 
  2136 * Simpler definition of function space in ZF;
  2137 
  2138 * new results about cardinal and ordinal arithmetic in ZF;
  2139 
  2140 * 'subtype' facility in HOL for introducing new types as subsets of existing
  2141 types;
  2142 
  2143 
  2144 $Id$