NEWS
author wenzelm
Wed Dec 05 02:58:04 2001 +0100 (2001-12-05)
changeset 12364 108cdda23ab3
parent 12335 db4d5f498742
child 12405 9b16f99fd7b9
permissions -rw-r--r--
* Pure/Provers/classical: simplified integration with pure rule
attributes and methods;
     1 
     2 Isabelle NEWS -- history user-relevant changes
     3 ==============================================
     4 
     5 New in Isabelle2001 (?? 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/Provers/classical: simplified integration with pure rule
   113 attributes and methods; the classical "intro?/elim?/dest?"
   114 declarations coincide with the pure ones; the "rule" method no longer
   115 includes classically swapped intros; "intro" and "elim" methods no
   116 longer pick rules from the context; also got rid of ML declarations
   117 AddXIs/AddXEs/AddXDs; all of this has some potential for
   118 INCOMPATIBILITY;
   119 
   120 * Provers/simplifier: 'simplified' attribute may refer to explicit
   121 rules instead of full simplifier context; 'iff' attribute handles
   122 conditional rules;
   123 
   124 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
   125 
   126 * HOL: 'recdef' now fails on unfinished automated proofs, use
   127 "(permissive)" option to recover old behavior;
   128 
   129 * HOL: 'inductive' no longer features separate (collective) attributes
   130 for 'intros' (was found too confusing);
   131 
   132 * HOLCF: domain package adapted to new-style theories, e.g. see
   133 HOLCF/ex/Dnat.thy;
   134 
   135 * ZF: proper integration of logic-specific tools and packages,
   136 including theory commands '(co)inductive', '(co)datatype',
   137 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
   138 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
   139 
   140 
   141 
   142 *** HOL ***
   143 
   144 * HOL: moved over to sane numeral syntax; the new policy is as
   145 follows:
   146 
   147   - 0 and 1 are polymorphic constants, which are defined on any
   148   numeric type (nat, int, real etc.);
   149 
   150   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
   151   binary representation internally;
   152 
   153   - type nat has special constructor Suc, and generally prefers Suc 0
   154   over 1::nat and Suc (Suc 0) over 2::nat;
   155 
   156 This change may cause significant problems of INCOMPATIBILITY; here
   157 are some hints on converting existing sources:
   158 
   159   - due to the new "num" token, "-0" and "-1" etc. are now atomic
   160   entities, so expressions involving "-" (unary or binary minus) need
   161   to be spaced properly;
   162 
   163   - existing occurrences of "1" may need to be constraint "1::nat" or
   164   even replaced by Suc 0; similar for old "2";
   165 
   166   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
   167 
   168   - remove all special provisions on numerals in proofs;
   169 
   170 * HOL: the class of all HOL types is now called "type" rather than
   171 "term"; INCOMPATIBILITY, need to adapt references to this type class
   172 in axclass/classes, instance/arities, and (usually rare) occurrences
   173 in typings (of consts etc.); internally the class is called
   174 "HOL.type", ML programs should refer to HOLogic.typeS;
   175 
   176 * HOL/record package improvements:
   177   - new derived operations "fields" to build a partial record section,
   178     "extend" to promote a fixed record to a record scheme, and
   179     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
   180     declared as simp by default;
   181   - removed "make_scheme" operations (use "make" with "extend") --
   182     INCOMPATIBILITY;
   183   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
   184   - provides cases/induct rules for use with corresponding Isar
   185     methods (for concrete records, record schemes, concrete more
   186     parts, and schematic more parts -- in that order);
   187   - internal definitions directly based on a light-weight abstract
   188     theory of product types over typedef rather than datatype;
   189 
   190 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
   191 
   192 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
   193 (beware of argument permutation!);
   194 
   195 * HOL: linorder_less_split superseded by linorder_cases;
   196 
   197 * HOL: added "The" definite description operator; move Hilbert's "Eps"
   198 to peripheral theory "Hilbert_Choice";
   199 
   200 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
   201 in this (rare) case use:
   202 
   203   delSWrapper "split_all_tac"
   204   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
   205 
   206 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
   207 MAY FAIL;
   208 
   209 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
   210 Isabelle's type classes, ^ on functions and relations has too general
   211 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
   212 necessary to attach explicit type constraints;
   213 
   214 * HOL: syntax translations now work properly with numerals and records
   215 expressions;
   216 
   217 * HOL/GroupTheory: group theory examples including Sylow's theorem, by
   218 Florian Kammüller;
   219 
   220 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
   221 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
   222 renamed "Product_Type.unit";
   223 
   224 
   225 *** HOLCF ***
   226 
   227 * proper rep_datatype lift (see theory Lift) instead of ML hacks --
   228 potential INCOMPATIBILITY; now use plain induct_tac instead of former
   229 lift.induct_tac, always use UU instead of Undef;
   230 
   231 
   232 *** ZF ***
   233 
   234 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
   235 typeless version of the formalism;
   236 
   237 * ZF/Induct: new directory for examples of inductive definitions,
   238 including theory Multiset for multiset orderings;
   239 
   240 * ZF: the integer library now covers quotients and remainders, with
   241 many laws relating division to addition, multiplication, etc.;
   242 
   243 
   244 *** General ***
   245 
   246 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
   247 variable proof controls level of detail: 0 = no proofs (only oracle
   248 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
   249 also ref manual for further ML interfaces;
   250 
   251 * Pure/axclass: removed obsolete ML interface
   252 goal_subclass/goal_arity;
   253 
   254 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
   255 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
   256 separate tokens, so expressions involving minus need to be spaced
   257 properly;
   258 
   259 * Pure/syntax: support non-oriented infixes, using keyword "infix"
   260 rather than "infixl" or "infixr";
   261 
   262 * Pure/syntax: concrete syntax for dummy type variables admits genuine
   263 sort constraint specifications in type inference; e.g. "x::_::foo"
   264 ensures that the type of "x" is of sort "foo" (but not necessarily a
   265 type variable);
   266 
   267 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
   268 control output of nested => (types); the default behavior is
   269 "type_brackets";
   270 
   271 * Pure/syntax: builtin parse translation for "_constify" turns valued
   272 tokens into AST constants;
   273 
   274 * Pure/syntax: prefer later declarations of translations and print
   275 translation functions; potential INCOMPATIBILITY: need to reverse
   276 multiple declarations for same syntax element constant;
   277 
   278 * Provers/classical: renamed addaltern to addafter, addSaltern to
   279 addSafter;
   280 
   281 * Provers/clasimp: ``iff'' declarations now handle conditional rules
   282 as well;
   283 
   284 * system: refrain from any attempt at filtering input streams; no
   285 longer support ``8bit'' encoding of old isabelle font, instead proper
   286 iso-latin characters may now be used;
   287 
   288 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
   289 
   290 * system: Proof General keywords specification is now part of the
   291 Isabelle distribution (see etc/isar-keywords.el);
   292 
   293 * system: smart selection of Isabelle process versus Isabelle
   294 interface, accommodates case-insensitive file systems (e.g. HFS+); may
   295 run both "isabelle" and "Isabelle" even if file names are badly
   296 damaged (executable inspects the case of the first letter of its own
   297 name); added separate "isabelle-process" and "isabelle-interface";
   298 
   299 
   300 
   301 New in Isabelle99-2 (February 2001)
   302 -----------------------------------
   303 
   304 *** Overview of INCOMPATIBILITIES ***
   305 
   306 * HOL: please note that theories in the Library and elsewhere often use the
   307 new-style (Isar) format; to refer to their theorems in an ML script you must
   308 bind them to ML identifers by e.g.	val thm_name = thm "thm_name";
   309 
   310 * HOL: inductive package no longer splits induction rule aggressively,
   311 but only as far as specified by the introductions given; the old
   312 format may be recovered via ML function complete_split_rule or attribute
   313 'split_rule (complete)';
   314 
   315 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
   316 gfp_Tarski to gfp_unfold;
   317 
   318 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
   319 
   320 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
   321 relation); infix "^^" has been renamed "``"; infix "``" has been
   322 renamed "`"; "univalent" has been renamed "single_valued";
   323 
   324 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
   325 operation;
   326 
   327 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
   328 
   329 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
   330 
   331 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
   332 consequence, it is no longer monotonic wrt. the local goal context
   333 (which is now passed through the inductive cases);
   334 
   335 * Document preparation: renamed standard symbols \<ll> to \<lless> and
   336 \<gg> to \<ggreater>;
   337 
   338 
   339 *** Document preparation ***
   340 
   341 * \isabellestyle{NAME} selects version of Isabelle output (currently
   342 available: are "it" for near math-mode best-style output, "sl" for
   343 slanted text style, and "tt" for plain type-writer; if no
   344 \isabellestyle command is given, output is according to slanted
   345 type-writer);
   346 
   347 * support sub/super scripts (for single symbols only), input syntax is
   348 like this: "A\<^sup>*" or "A\<^sup>\<star>";
   349 
   350 * some more standard symbols; see Appendix A of the system manual for
   351 the complete list of symbols defined in isabellesym.sty;
   352 
   353 * improved isabelle style files; more abstract symbol implementation
   354 (should now use \isamath{...} and \isatext{...} in custom symbol
   355 definitions);
   356 
   357 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
   358 state; Note that presentation of goal states does not conform to
   359 actual human-readable proof documents.  Please do not include goal
   360 states into document output unless you really know what you are doing!
   361 
   362 * proper indentation of antiquoted output with proportional LaTeX
   363 fonts;
   364 
   365 * no_document ML operator temporarily disables LaTeX document
   366 generation;
   367 
   368 * isatool unsymbolize tunes sources for plain ASCII communication;
   369 
   370 
   371 *** Isar ***
   372 
   373 * Pure: Isar now suffers initial goal statements to contain unbound
   374 schematic variables (this does not conform to actual readable proof
   375 documents, due to unpredictable outcome and non-compositional proof
   376 checking); users who know what they are doing may use schematic goals
   377 for Prolog-style synthesis of proven results;
   378 
   379 * Pure: assumption method (an implicit finishing) now handles actual
   380 rules as well;
   381 
   382 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
   383 initial goal, declare "that" only as Pure intro (only for single
   384 steps); the "that" rule assumption may now be involved in implicit
   385 finishing, thus ".." becomes a feasible for trivial obtains;
   386 
   387 * Pure: default proof step now includes 'intro_classes'; thus trivial
   388 instance proofs may be performed by "..";
   389 
   390 * Pure: ?thesis / ?this / "..." now work for pure meta-level
   391 statements as well;
   392 
   393 * Pure: more robust selection of calculational rules;
   394 
   395 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
   396 rule (as well as the assumption rule);
   397 
   398 * Pure: 'thm_deps' command visualizes dependencies of theorems and
   399 lemmas, using the graph browser tool;
   400 
   401 * Pure: predict failure of "show" in interactive mode;
   402 
   403 * Pure: 'thms_containing' now takes actual terms as arguments;
   404 
   405 * HOL: improved method 'induct' --- now handles non-atomic goals
   406 (potential INCOMPATIBILITY); tuned error handling;
   407 
   408 * HOL: cases and induct rules now provide explicit hints about the
   409 number of facts to be consumed (0 for "type" and 1 for "set" rules);
   410 any remaining facts are inserted into the goal verbatim;
   411 
   412 * HOL: local contexts (aka cases) may now contain term bindings as
   413 well; the 'cases' and 'induct' methods new provide a ?case binding for
   414 the result to be shown in each case;
   415 
   416 * HOL: added 'recdef_tc' command;
   417 
   418 * isatool convert assists in eliminating legacy ML scripts;
   419 
   420 
   421 *** HOL ***
   422 
   423 * HOL/Library: a collection of generic theories to be used together
   424 with main HOL; the theory loader path already includes this directory
   425 by default; the following existing theories have been moved here:
   426 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
   427 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
   428 
   429 * HOL/Unix: "Some aspects of Unix file-system security", a typical
   430 modelling and verification task performed in Isabelle/HOL +
   431 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
   432 
   433 * HOL/Algebra: special summation operator SUM no longer exists, it has
   434 been replaced by setsum; infix 'assoc' now has priority 50 (like
   435 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
   436 'domain', this makes the theory consistent with mathematical
   437 literature;
   438 
   439 * HOL basics: added overloaded operations "inverse" and "divide"
   440 (infix "/"), syntax for generic "abs" operation, generic summation
   441 operator \<Sum>;
   442 
   443 * HOL/typedef: simplified package, provide more useful rules (see also
   444 HOL/subset.thy);
   445 
   446 * HOL/datatype: induction rule for arbitrarily branching datatypes is
   447 now expressed as a proper nested rule (old-style tactic scripts may
   448 require atomize_strip_tac to cope with non-atomic premises);
   449 
   450 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
   451 to "split_conv" (old name still available for compatibility);
   452 
   453 * HOL: improved concrete syntax for strings (e.g. allows translation
   454 rules with string literals);
   455 
   456 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
   457  and Fleuriot's mechanization of analysis, including the transcendental
   458  functions for the reals;
   459 
   460 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
   461 
   462 
   463 *** CTT ***
   464 
   465 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
   466 "lam" is displayed as TWO lambda-symbols
   467 
   468 * CTT: theory Main now available, containing everything (that is, Bool
   469 and Arith);
   470 
   471 
   472 *** General ***
   473 
   474 * Pure: the Simplifier has been implemented properly as a derived rule
   475 outside of the actual kernel (at last!); the overall performance
   476 penalty in practical applications is about 50%, while reliability of
   477 the Isabelle inference kernel has been greatly improved;
   478 
   479 * print modes "brackets" and "no_brackets" control output of nested =>
   480 (types) and ==> (props); the default behaviour is "brackets";
   481 
   482 * Provers: fast_tac (and friends) now handle actual object-logic rules
   483 as assumptions as well;
   484 
   485 * system: support Poly/ML 4.0;
   486 
   487 * system: isatool install handles KDE version 1 or 2;
   488 
   489 
   490 
   491 New in Isabelle99-1 (October 2000)
   492 ----------------------------------
   493 
   494 *** Overview of INCOMPATIBILITIES ***
   495 
   496 * HOL: simplification of natural numbers is much changed; to partly
   497 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
   498 issue the following ML commands:
   499 
   500   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
   501   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
   502 
   503 * HOL: simplification no longer dives into case-expressions; this is
   504 controlled by "t.weak_case_cong" for each datatype t;
   505 
   506 * HOL: nat_less_induct renamed to less_induct;
   507 
   508 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
   509 fixsome to patch .thy and .ML sources automatically;
   510 
   511   select_equality  -> some_equality
   512   select_eq_Ex     -> some_eq_ex
   513   selectI2EX       -> someI2_ex
   514   selectI2         -> someI2
   515   selectI          -> someI
   516   select1_equality -> some1_equality
   517   Eps_sym_eq       -> some_sym_eq_trivial
   518   Eps_eq           -> some_eq_trivial
   519 
   520 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
   521 
   522 * HOL: removed obsolete theorem binding expand_if (refer to split_if
   523 instead);
   524 
   525 * HOL: the recursion equations generated by 'recdef' are now called
   526 f.simps instead of f.rules;
   527 
   528 * HOL: qed_spec_mp now also handles bounded ALL as well;
   529 
   530 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
   531 sometimes be needed;
   532 
   533 * HOL: the constant for "f``x" is now "image" rather than "op ``";
   534 
   535 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
   536 
   537 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
   538 product is now "<*>" instead of "Times"; the lexicographic product is
   539 now "<*lex*>" instead of "**";
   540 
   541 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
   542 of main HOL, but was unused); better use HOL's datatype package;
   543 
   544 * HOL: removed "symbols" syntax for constant "override" of theory Map;
   545 the old syntax may be recovered as follows:
   546 
   547   syntax (symbols)
   548     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
   549       (infixl "\\<oplus>" 100)
   550 
   551 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   552 
   553 * HOL/ML: even fewer consts are declared as global (see theories Ord,
   554 Lfp, Gfp, WF); this only affects ML packages that refer to const names
   555 internally;
   556 
   557 * HOL and ZF: syntax for quotienting wrt an equivalence relation
   558 changed from A/r to A//r;
   559 
   560 * ZF: new treatment of arithmetic (nat & int) may break some old
   561 proofs;
   562 
   563 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
   564 rulify -> rule_format, elimify -> elim_format, ...);
   565 
   566 * Isar/Provers: intro/elim/dest attributes changed; renamed
   567 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
   568 should have to change intro!! to intro? only); replaced "delrule" by
   569 "rule del";
   570 
   571 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
   572 
   573 * Provers: strengthened force_tac by using new first_best_tac;
   574 
   575 * LaTeX document preparation: several changes of isabelle.sty (see
   576 lib/texinputs);
   577 
   578 
   579 *** Document preparation ***
   580 
   581 * formal comments (text blocks etc.) in new-style theories may now
   582 contain antiquotations of thm/prop/term/typ/text to be presented
   583 according to latex print mode; concrete syntax is like this:
   584 @{term[show_types] "f(x) = a + x"};
   585 
   586 * isatool mkdir provides easy setup of Isabelle session directories,
   587 including proper document sources;
   588 
   589 * generated LaTeX sources are now deleted after successful run
   590 (isatool document -c); may retain a copy somewhere else via -D option
   591 of isatool usedir;
   592 
   593 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
   594 style files, achieving self-contained LaTeX sources and simplifying
   595 LaTeX debugging;
   596 
   597 * old-style theories now produce (crude) LaTeX output as well;
   598 
   599 * browser info session directories are now self-contained (may be put
   600 on WWW server seperately); improved graphs of nested sessions; removed
   601 graph for 'all sessions';
   602 
   603 * several improvements in isabelle style files; \isabellestyle{it}
   604 produces fake math mode output; \isamarkupheader is now \section by
   605 default; see lib/texinputs/isabelle.sty etc.;
   606 
   607 
   608 *** Isar ***
   609 
   610 * Isar/Pure: local results and corresponding term bindings are now
   611 subject to Hindley-Milner polymorphism (similar to ML); this
   612 accommodates incremental type-inference very nicely;
   613 
   614 * Isar/Pure: new derived language element 'obtain' supports
   615 generalized existence reasoning;
   616 
   617 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
   618 support accumulation of results, without applying any rules yet;
   619 useful to collect intermediate results without explicit name
   620 references, and for use with transitivity rules with more than 2
   621 premises;
   622 
   623 * Isar/Pure: scalable support for case-analysis type proofs: new
   624 'case' language element refers to local contexts symbolically, as
   625 produced by certain proof methods; internally, case names are attached
   626 to theorems as "tags";
   627 
   628 * Isar/Pure: theory command 'hide' removes declarations from
   629 class/type/const name spaces;
   630 
   631 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
   632 indicate potential overloading;
   633 
   634 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
   635 
   636 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
   637 "{a,b,c}" instead of {a,b,c};
   638 
   639 * Isar/Pure now provides its own version of intro/elim/dest
   640 attributes; useful for building new logics, but beware of confusion
   641 with the version in Provers/classical;
   642 
   643 * Isar/Pure: the local context of (non-atomic) goals is provided via
   644 case name 'antecedent';
   645 
   646 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
   647 to the current context is now done automatically);
   648 
   649 * Isar/Pure: theory command 'method_setup' provides a simple interface
   650 for definining proof methods in ML;
   651 
   652 * Isar/Provers: intro/elim/dest attributes changed; renamed
   653 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
   654 most cases, one should have to change intro!! to intro? only);
   655 replaced "delrule" by "rule del";
   656 
   657 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
   658 'symmetric' attribute (the latter supercedes [RS sym]);
   659 
   660 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
   661 method modifier); 'simp' method: 'only:' modifier removes loopers as
   662 well (including splits);
   663 
   664 * Isar/Provers: Simplifier and Classical methods now support all kind
   665 of modifiers used in the past, including 'cong', 'iff', etc.
   666 
   667 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
   668 of Simplifier and Classical reasoner);
   669 
   670 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
   671 now support named cases; major packages (inductive, datatype, primrec,
   672 recdef) support case names and properly name parameters;
   673 
   674 * Isar/HOL: new transitivity rules for substitution in inequalities --
   675 monotonicity conditions are extracted to be proven at end of
   676 calculations;
   677 
   678 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
   679 method anyway;
   680 
   681 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
   682 split_if split_if_asm; datatype package provides theorems foo.splits =
   683 foo.split foo.split_asm for each datatype;
   684 
   685 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
   686 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
   687 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
   688 use "(cases (simplified))" method in proper proof texts);
   689 
   690 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
   691 
   692 * Isar: names of theorems etc. may be natural numbers as well;
   693 
   694 * Isar: 'pr' command: optional arguments for goals_limit and
   695 ProofContext.prems_limit; no longer prints theory contexts, but only
   696 proof states;
   697 
   698 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
   699 additional print modes to be specified; e.g. "pr(latex)" will print
   700 proof state according to the Isabelle LaTeX style;
   701 
   702 * Isar: improved support for emulating tactic scripts, including proof
   703 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
   704 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
   705 (for HOL datatypes);
   706 
   707 * Isar: simplified (more robust) goal selection of proof methods: 1st
   708 goal, all goals, or explicit goal specifier (tactic emulation); thus
   709 'proof method scripts' have to be in depth-first order;
   710 
   711 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
   712 
   713 * Isar: removed 'help' command, which hasn't been too helpful anyway;
   714 should instead use individual commands for printing items
   715 (print_commands, print_methods etc.);
   716 
   717 * Isar: added 'nothing' --- the empty list of theorems;
   718 
   719 
   720 *** HOL ***
   721 
   722 * HOL/MicroJava: formalization of a fragment of Java, together with a
   723 corresponding virtual machine and a specification of its bytecode
   724 verifier and a lightweight bytecode verifier, including proofs of
   725 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
   726 Cornelia Pusch (see also the homepage of project Bali at
   727 http://isabelle.in.tum.de/Bali/);
   728 
   729 * HOL/Algebra: new theory of rings and univariate polynomials, by
   730 Clemens Ballarin;
   731 
   732 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
   733 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
   734 Rasmussen;
   735 
   736 * HOL/Lattice: fundamental concepts of lattice theory and order
   737 structures, including duals, properties of bounds versus algebraic
   738 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
   739 Theorem for complete lattices etc.; may also serve as a demonstration
   740 for abstract algebraic reasoning using axiomatic type classes, and
   741 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
   742 
   743 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
   744 von Oheimb;
   745 
   746 * HOL/IMPP: extension of IMP with local variables and mutually
   747 recursive procedures, by David von Oheimb;
   748 
   749 * HOL/Lambda: converted into new-style theory and document;
   750 
   751 * HOL/ex/Multiquote: example of multiple nested quotations and
   752 anti-quotations -- basically a generalized version of de-Bruijn
   753 representation; very useful in avoiding lifting of operations;
   754 
   755 * HOL/record: added general record equality rule to simpset; fixed
   756 select-update simplification procedure to handle extended records as
   757 well; admit "r" as field name;
   758 
   759 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
   760 other numeric types and also as the identity of groups, rings, etc.;
   761 
   762 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
   763 Types nat and int belong to this axclass;
   764 
   765 * HOL: greatly improved simplification involving numerals of type nat, int, real:
   766    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
   767    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
   768   two terms #m*u and #n*u are replaced by #(m+n)*u
   769     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
   770   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
   771     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
   772 
   773 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
   774 powerful prover for predicate logic but knows nothing of clasets; see
   775 ex/mesontest.ML and ex/mesontest2.ML for example applications;
   776 
   777 * HOL: new version of "case_tac" subsumes both boolean case split and
   778 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
   779 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
   780 
   781 * HOL: simplification no longer dives into case-expressions: only the
   782 selector expression is simplified, but not the remaining arms; to
   783 enable full simplification of case-expressions for datatype t, you may
   784 remove t.weak_case_cong from the simpset, either globally (Delcongs
   785 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
   786 
   787 * HOL/recdef: the recursion equations generated by 'recdef' for
   788 function 'f' are now called f.simps instead of f.rules; if all
   789 termination conditions are proved automatically, these simplification
   790 rules are added to the simpset, as in primrec; rules may be named
   791 individually as well, resulting in a separate list of theorems for
   792 each equation;
   793 
   794 * HOL/While is a new theory that provides a while-combinator. It
   795 permits the definition of tail-recursive functions without the
   796 provision of a termination measure. The latter is necessary once the
   797 invariant proof rule for while is applied.
   798 
   799 * HOL: new (overloaded) notation for the set of elements below/above
   800 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
   801 
   802 * HOL: theorems impI, allI, ballI bound as "strip";
   803 
   804 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
   805 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
   806 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
   807 
   808 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   809 
   810 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
   811 main HOL, but was unused);
   812 
   813 * HOL: fewer consts declared as global (e.g. have to refer to
   814 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
   815 
   816 * HOL: tuned AST representation of nested pairs, avoiding bogus output
   817 in case of overlap with user translations (e.g. judgements over
   818 tuples); (note that the underlying logical represenation is still
   819 bogus);
   820 
   821 
   822 *** ZF ***
   823 
   824 * ZF: simplification automatically cancels common terms in arithmetic
   825 expressions over nat and int;
   826 
   827 * ZF: new treatment of nat to minimize type-checking: all operators
   828 coerce their operands to a natural number using the function natify,
   829 making the algebraic laws unconditional;
   830 
   831 * ZF: as above, for int: operators coerce their operands to an integer
   832 using the function intify;
   833 
   834 * ZF: the integer library now contains many of the usual laws for the
   835 orderings, including $<=, and monotonicity laws for $+ and $*;
   836 
   837 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
   838 simplification;
   839 
   840 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
   841 to the simplifier and classical reasoner simultaneously;
   842 
   843 
   844 *** General ***
   845 
   846 * Provers: blast_tac now handles actual object-logic rules as
   847 assumptions; note that auto_tac uses blast_tac internally as well;
   848 
   849 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
   850 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
   851 
   852 * Provers: delrules now handles destruct rules as well (no longer need
   853 explicit make_elim);
   854 
   855 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
   856   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   857 use instead the strong form,
   858   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   859 in HOL, FOL and ZF the function cla_make_elim will create such rules
   860 from destruct-rules;
   861 
   862 * Provers: Simplifier.easy_setup provides a fast path to basic
   863 Simplifier setup for new object-logics;
   864 
   865 * Pure: AST translation rules no longer require constant head on LHS;
   866 
   867 * Pure: improved name spaces: ambiguous output is qualified; support
   868 for hiding of names;
   869 
   870 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
   871 XSYMBOL_HOME; no longer need to do manual configuration in most
   872 situations;
   873 
   874 * system: compression of ML heaps images may now be controlled via -c
   875 option of isabelle and isatool usedir (currently only observed by
   876 Poly/ML);
   877 
   878 * system: isatool installfonts may handle X-Symbol fonts as well (very
   879 useful for remote X11);
   880 
   881 * system: provide TAGS file for Isabelle sources;
   882 
   883 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
   884 order;
   885 
   886 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
   887 timing flag supersedes proof_timing and Toplevel.trace;
   888 
   889 * ML: new combinators |>> and |>>> for incremental transformations
   890 with secondary results (e.g. certain theory extensions):
   891 
   892 * ML: PureThy.add_defs gets additional argument to indicate potential
   893 overloading (usually false);
   894 
   895 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
   896 results;
   897 
   898 
   899 
   900 New in Isabelle99 (October 1999)
   901 --------------------------------
   902 
   903 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   904 
   905 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
   906 are no longer simplified.  (This allows the simplifier to unfold recursive
   907 functional programs.)  To restore the old behaviour, declare
   908 
   909     Delcongs [if_weak_cong];
   910 
   911 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
   912 complement;
   913 
   914 * HOL: the predicate "inj" is now defined by translation to "inj_on";
   915 
   916 * HOL/datatype: mutual_induct_tac no longer exists --
   917   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
   918 
   919 * HOL/typedef: fixed type inference for representing set; type
   920 arguments now have to occur explicitly on the rhs as type constraints;
   921 
   922 * ZF: The con_defs part of an inductive definition may no longer refer
   923 to constants declared in the same theory;
   924 
   925 * HOL, ZF: the function mk_cases, generated by the inductive
   926 definition package, has lost an argument.  To simplify its result, it
   927 uses the default simpset instead of a supplied list of theorems.
   928 
   929 * HOL/List: the constructors of type list are now Nil and Cons;
   930 
   931 * Simplifier: the type of the infix ML functions
   932         setSSolver addSSolver setSolver addSolver
   933 is now  simpset * solver -> simpset  where `solver' is a new abstract type
   934 for packaging solvers. A solver is created via
   935         mk_solver: string -> (thm list -> int -> tactic) -> solver
   936 where the string argument is only a comment.
   937 
   938 
   939 *** Proof tools ***
   940 
   941 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
   942 decision procedure for linear arithmetic. Currently it is used for
   943 types `nat', `int', and `real' in HOL (see below); it can, should and
   944 will be instantiated for other types and logics as well.
   945 
   946 * The simplifier now accepts rewrite rules with flexible heads, eg
   947      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
   948   They are applied like any rule with a non-pattern lhs, i.e. by first-order
   949   matching.
   950 
   951 
   952 *** General ***
   953 
   954 * New Isabelle/Isar subsystem provides an alternative to traditional
   955 tactical theorem proving; together with the ProofGeneral/isar user
   956 interface it offers an interactive environment for developing human
   957 readable proof documents (Isar == Intelligible semi-automated
   958 reasoning); for further information see isatool doc isar-ref,
   959 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
   960 
   961 * improved and simplified presentation of theories: better HTML markup
   962 (including colors), graph views in several sizes; isatool usedir now
   963 provides a proper interface for user theories (via -P option); actual
   964 document preparation based on (PDF)LaTeX is available as well (for
   965 new-style theories only); see isatool doc system for more information;
   966 
   967 * native support for Proof General, both for classic Isabelle and
   968 Isabelle/Isar;
   969 
   970 * ML function thm_deps visualizes dependencies of theorems and lemmas,
   971 using the graph browser tool;
   972 
   973 * Isabelle manuals now also available as PDF;
   974 
   975 * theory loader rewritten from scratch (may not be fully
   976 bug-compatible); old loadpath variable has been replaced by show_path,
   977 add_path, del_path, reset_path functions; new operations such as
   978 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
   979 isatool doc ref);
   980 
   981 * improved isatool install: option -k creates KDE application icon,
   982 option -p DIR installs standalone binaries;
   983 
   984 * added ML_PLATFORM setting (useful for cross-platform installations);
   985 more robust handling of platform specific ML images for SML/NJ;
   986 
   987 * the settings environment is now statically scoped, i.e. it is never
   988 created again in sub-processes invoked from isabelle, isatool, or
   989 Isabelle;
   990 
   991 * path element specification '~~' refers to '$ISABELLE_HOME';
   992 
   993 * in locales, the "assumes" and "defines" parts may be omitted if
   994 empty;
   995 
   996 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
   997 long arrows);
   998 
   999 * new print_mode "HTML";
  1000 
  1001 * new flag show_tags controls display of tags of theorems (which are
  1002 basically just comments that may be attached by some tools);
  1003 
  1004 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  1005 mode and goal output format:
  1006 
  1007 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  1008 244c244
  1009 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  1010 ---
  1011 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  1012 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  1013 181c181
  1014 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  1015 ---
  1016 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  1017 
  1018 * function bind_thms stores lists of theorems (cf. bind_thm);
  1019 
  1020 * new shorthand tactics ftac, eatac, datac, fatac;
  1021 
  1022 * qed (and friends) now accept "" as result name; in that case the
  1023 theorem is not stored, but proper checks and presentation of the
  1024 result still apply;
  1025 
  1026 * theorem database now also indexes constants "Trueprop", "all",
  1027 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  1028 
  1029 
  1030 *** HOL ***
  1031 
  1032 ** HOL arithmetic **
  1033 
  1034 * There are now decision procedures for linear arithmetic over nat and
  1035 int:
  1036 
  1037 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  1038 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  1039 are treated as atomic; subformulae not involving type `nat' or `int'
  1040 are ignored; quantified subformulae are ignored unless they are
  1041 positive universal or negative existential. The tactic has to be
  1042 invoked by hand and can be a little bit slow. In particular, the
  1043 running time is exponential in the number of occurrences of `min' and
  1044 `max', and `-' on `nat'.
  1045 
  1046 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  1047 (negated) (in)equalities among the premises and the conclusion into
  1048 account (i.e. no compound formulae) and does not know about `min' and
  1049 `max', and `-' on `nat'. It is fast and is used automatically by the
  1050 simplifier.
  1051 
  1052 NB: At the moment, these decision procedures do not cope with mixed
  1053 nat/int formulae where the two parts interact, such as `m < n ==>
  1054 int(m) < int(n)'.
  1055 
  1056 * HOL/Numeral provides a generic theory of numerals (encoded
  1057 efficiently as bit strings); setup for types nat/int/real is in place;
  1058 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  1059 int, existing theories and proof scripts may require a few additional
  1060 type constraints;
  1061 
  1062 * integer division and remainder can now be performed on constant
  1063 arguments;
  1064 
  1065 * many properties of integer multiplication, division and remainder
  1066 are now available;
  1067 
  1068 * An interface to the Stanford Validity Checker (SVC) is available through the
  1069 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  1070 are proved automatically.  SVC must be installed separately, and its results
  1071 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  1072 invocation of the underlying oracle).  For SVC see
  1073   http://verify.stanford.edu/SVC
  1074 
  1075 * IsaMakefile: the HOL-Real target now builds an actual image;
  1076 
  1077 
  1078 ** HOL misc **
  1079 
  1080 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  1081 (in Isabelle/Isar) -- by Gertrud Bauer;
  1082 
  1083 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  1084 analysis for assembly languages with subtypes;
  1085 
  1086 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  1087 -- avoids syntactic ambiguities and treats state, transition, and
  1088 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  1089 changed syntax and (many) tactics;
  1090 
  1091 * HOL/inductive: Now also handles more general introduction rules such
  1092   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  1093   theorems are now maintained within the theory (maintained via the
  1094   "mono" attribute);
  1095 
  1096 * HOL/datatype: Now also handles arbitrarily branching datatypes
  1097   (using function types) such as
  1098 
  1099   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  1100 
  1101 * HOL/record: record_simproc (part of the default simpset) takes care
  1102 of selectors applied to updated records; record_split_tac is no longer
  1103 part of the default claset; update_defs may now be removed from the
  1104 simpset in many cases; COMPATIBILITY: old behavior achieved by
  1105 
  1106   claset_ref () := claset() addSWrapper record_split_wrapper;
  1107   Delsimprocs [record_simproc]
  1108 
  1109 * HOL/typedef: fixed type inference for representing set; type
  1110 arguments now have to occur explicitly on the rhs as type constraints;
  1111 
  1112 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  1113 names rather than an ML expression;
  1114 
  1115 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  1116 supplied later.  Program schemes can be defined, such as
  1117     "While B C s = (if B s then While B C (C s) else s)"
  1118 where the well-founded relation can be chosen after B and C have been given.
  1119 
  1120 * HOL/List: the constructors of type list are now Nil and Cons;
  1121 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  1122 course, ML tools referring to List.list.op # etc. have to be adapted;
  1123 
  1124 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  1125 disabled by default; run isabelle with option -m HOL to get back to
  1126 the original Gordon/HOL-style output;
  1127 
  1128 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  1129 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  1130 
  1131 * HOL basic syntax simplified (more orthogonal): all variants of
  1132 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  1133 Eps operator is provided as well: "SOME x. P[x]";
  1134 
  1135 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  1136 
  1137 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  1138 thus available for user theories;
  1139 
  1140 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  1141 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  1142 time;
  1143 
  1144 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  1145 several times and then mp;
  1146 
  1147 
  1148 *** LK ***
  1149 
  1150 * the notation <<...>> is now available as a notation for sequences of
  1151 formulas;
  1152 
  1153 * the simplifier is now installed
  1154 
  1155 * the axiom system has been generalized (thanks to Soren Heilmann)
  1156 
  1157 * the classical reasoner now has a default rule database
  1158 
  1159 
  1160 *** ZF ***
  1161 
  1162 * new primrec section allows primitive recursive functions to be given
  1163 directly (as in HOL) over datatypes and the natural numbers;
  1164 
  1165 * new tactics induct_tac and exhaust_tac for induction (or case
  1166 analysis) over datatypes and the natural numbers;
  1167 
  1168 * the datatype declaration of type T now defines the recursor T_rec;
  1169 
  1170 * simplification automatically does freeness reasoning for datatype
  1171 constructors;
  1172 
  1173 * automatic type-inference, with AddTCs command to insert new
  1174 type-checking rules;
  1175 
  1176 * datatype introduction rules are now added as Safe Introduction rules
  1177 to the claset;
  1178 
  1179 * the syntax "if P then x else y" is now available in addition to
  1180 if(P,x,y);
  1181 
  1182 
  1183 *** Internal programming interfaces ***
  1184 
  1185 * tuned simplifier trace output; new flag debug_simp;
  1186 
  1187 * structures Vartab / Termtab (instances of TableFun) offer efficient
  1188 tables indexed by indexname_ord / term_ord (compatible with aconv);
  1189 
  1190 * AxClass.axclass_tac lost the theory argument;
  1191 
  1192 * tuned current_goals_markers semantics: begin / end goal avoids
  1193 printing empty lines;
  1194 
  1195 * removed prs and prs_fn hook, which was broken because it did not
  1196 include \n in its semantics, forcing writeln to add one
  1197 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  1198 string -> unit if you really want to output text without newline;
  1199 
  1200 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  1201 plain output, interface builders may have to enable 'isabelle_font'
  1202 mode to get Isabelle font glyphs as before;
  1203 
  1204 * refined token_translation interface; INCOMPATIBILITY: output length
  1205 now of type real instead of int;
  1206 
  1207 * theory loader actions may be traced via new ThyInfo.add_hook
  1208 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  1209 your own database of information attached to *whole* theories -- as
  1210 opposed to intra-theory data slots offered via TheoryDataFun;
  1211 
  1212 * proper handling of dangling sort hypotheses (at last!);
  1213 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  1214 extra sort hypotheses that can be witnessed from the type signature;
  1215 the force_strip_shyps flag is gone, any remaining shyps are simply
  1216 left in the theorem (with a warning issued by strip_shyps_warning);
  1217 
  1218 
  1219 
  1220 New in Isabelle98-1 (October 1998)
  1221 ----------------------------------
  1222 
  1223 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1224 
  1225 * several changes of automated proof tools;
  1226 
  1227 * HOL: major changes to the inductive and datatype packages, including
  1228 some minor incompatibilities of theory syntax;
  1229 
  1230 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  1231 called `inj_on';
  1232 
  1233 * HOL: removed duplicate thms in Arith:
  1234   less_imp_add_less  should be replaced by  trans_less_add1
  1235   le_imp_add_le      should be replaced by  trans_le_add1
  1236 
  1237 * HOL: unary minus is now overloaded (new type constraints may be
  1238 required);
  1239 
  1240 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  1241 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  1242 now taken as an integer constant.
  1243 
  1244 * Pure: ML function 'theory_of' renamed to 'theory';
  1245 
  1246 
  1247 *** Proof tools ***
  1248 
  1249 * Simplifier:
  1250   1. Asm_full_simp_tac is now more aggressive.
  1251      1. It will sometimes reorient premises if that increases their power to
  1252         simplify.
  1253      2. It does no longer proceed strictly from left to right but may also
  1254         rotate premises to achieve further simplification.
  1255      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  1256      old Asm_full_simp_tac in that it does not rotate premises.
  1257   2. The simplifier now knows a little bit about nat-arithmetic.
  1258 
  1259 * Classical reasoner: wrapper mechanism for the classical reasoner now
  1260 allows for selected deletion of wrappers, by introduction of names for
  1261 wrapper functionals.  This implies that addbefore, addSbefore,
  1262 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  1263 and that adding two tactics with the same name overwrites the first
  1264 one (emitting a warning).
  1265   type wrapper = (int -> tactic) -> (int -> tactic)
  1266   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  1267   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  1268   delWrapper, delSWrapper: claset *  string            -> claset
  1269   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  1270 
  1271 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  1272 semantics; addbefore now affects only the unsafe part of step_tac
  1273 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  1274 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  1275 by Force_tac;
  1276 
  1277 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  1278 compWrapper; added safe wrapper (and access functions for it);
  1279 
  1280 * HOL/split_all_tac is now much faster and fails if there is nothing
  1281 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  1282 and the names of the automatically generated variables have changed.
  1283 split_all_tac has moved within claset() from unsafe wrappers to safe
  1284 wrappers, which means that !!-bound variables are split much more
  1285 aggressively, and safe_tac and clarify_tac now split such variables.
  1286 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  1287 Note: the same holds for record_split_tac, which does the job of
  1288 split_all_tac for record fields.
  1289 
  1290 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  1291 permanently to the default simpset using Addsplits just like
  1292 Addsimps. They can be removed via Delsplits just like
  1293 Delsimps. Lower-case versions are also available.
  1294 
  1295 * HOL/Simplifier: The rule split_if is now part of the default
  1296 simpset. This means that the simplifier will eliminate all occurrences
  1297 of if-then-else in the conclusion of a goal. To prevent this, you can
  1298 either remove split_if completely from the default simpset by
  1299 `Delsplits [split_if]' or remove it in a specific call of the
  1300 simplifier using `... delsplits [split_if]'.  You can also add/delete
  1301 other case splitting rules to/from the default simpset: every datatype
  1302 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  1303 t is the name of the datatype).
  1304 
  1305 * Classical reasoner / Simplifier combination: new force_tac (and
  1306 derivatives Force_tac, force) combines rewriting and classical
  1307 reasoning (and whatever other tools) similarly to auto_tac, but is
  1308 aimed to solve the given subgoal completely.
  1309 
  1310 
  1311 *** General ***
  1312 
  1313 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  1314 and `goalw': the theory is no longer needed as an explicit argument -
  1315 the current theory context is used; assumptions are no longer returned
  1316 at the ML-level unless one of them starts with ==> or !!; it is
  1317 recommended to convert to these new commands using isatool fixgoal
  1318 (backup your sources first!);
  1319 
  1320 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  1321 the current theory context, and 'theory' to lookup stored theories;
  1322 
  1323 * new theory section 'locale' for declaring constants, assumptions and
  1324 definitions that have local scope;
  1325 
  1326 * new theory section 'nonterminals' for purely syntactic types;
  1327 
  1328 * new theory section 'setup' for generic ML setup functions
  1329 (e.g. package initialization);
  1330 
  1331 * the distribution now includes Isabelle icons: see
  1332 lib/logo/isabelle-{small,tiny}.xpm;
  1333 
  1334 * isatool install - install binaries with absolute references to
  1335 ISABELLE_HOME/bin;
  1336 
  1337 * isatool logo -- create instances of the Isabelle logo (as EPS);
  1338 
  1339 * print mode 'emacs' reserved for Isamode;
  1340 
  1341 * support multiple print (ast) translations per constant name;
  1342 
  1343 * theorems involving oracles are now printed with a suffixed [!];
  1344 
  1345 
  1346 *** HOL ***
  1347 
  1348 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  1349 
  1350 * HOL/inductive package reorganized and improved: now supports mutual
  1351 definitions such as
  1352 
  1353   inductive EVEN ODD
  1354     intrs
  1355       null "0 : EVEN"
  1356       oddI "n : EVEN ==> Suc n : ODD"
  1357       evenI "n : ODD ==> Suc n : EVEN"
  1358 
  1359 new theorem list "elims" contains an elimination rule for each of the
  1360 recursive sets; inductive definitions now handle disjunctive premises
  1361 correctly (also ZF);
  1362 
  1363 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  1364 "mutual_induct" no longer exists - the induction rule is always
  1365 contained in "induct";
  1366 
  1367 
  1368 * HOL/datatype package re-implemented and greatly improved: now
  1369 supports mutually recursive datatypes such as
  1370 
  1371   datatype
  1372     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  1373             | SUM ('a aexp) ('a aexp)
  1374             | DIFF ('a aexp) ('a aexp)
  1375             | NUM 'a
  1376   and
  1377     'a bexp = LESS ('a aexp) ('a aexp)
  1378             | AND ('a bexp) ('a bexp)
  1379             | OR ('a bexp) ('a bexp)
  1380 
  1381 as well as indirectly recursive datatypes such as
  1382 
  1383   datatype
  1384     ('a, 'b) term = Var 'a
  1385                   | App 'b ((('a, 'b) term) list)
  1386 
  1387 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  1388 induction on mutually / indirectly recursive datatypes.
  1389 
  1390 Primrec equations are now stored in theory and can be accessed via
  1391 <function_name>.simps.
  1392 
  1393 INCOMPATIBILITIES:
  1394 
  1395   - Theories using datatypes must now have theory Datatype as an
  1396     ancestor.
  1397   - The specific <typename>.induct_tac no longer exists - use the
  1398     generic induct_tac instead.
  1399   - natE has been renamed to nat.exhaust - use exhaust_tac
  1400     instead of res_inst_tac ... natE. Note that the variable
  1401     names in nat.exhaust differ from the names in natE, this
  1402     may cause some "fragile" proofs to fail.
  1403   - The theorems split_<typename>_case and split_<typename>_case_asm
  1404     have been renamed to <typename>.split and <typename>.split_asm.
  1405   - Since default sorts of type variables are now handled correctly,
  1406     some datatype definitions may have to be annotated with explicit
  1407     sort constraints.
  1408   - Primrec definitions no longer require function name and type
  1409     of recursive argument.
  1410 
  1411 Consider using isatool fixdatatype to adapt your theories and proof
  1412 scripts to the new package (backup your sources first!).
  1413 
  1414 
  1415 * HOL/record package: considerably improved implementation; now
  1416 includes concrete syntax for record types, terms, updates; theorems
  1417 for surjective pairing and splitting !!-bound record variables; proof
  1418 support is as follows:
  1419 
  1420   1) standard conversions (selectors or updates applied to record
  1421 constructor terms) are part of the standard simpset;
  1422 
  1423   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  1424 made part of standard simpset and claset via addIffs;
  1425 
  1426   3) a tactic for record field splitting (record_split_tac) is part of
  1427 the standard claset (addSWrapper);
  1428 
  1429 To get a better idea about these rules you may retrieve them via
  1430 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  1431 the name of your record type.
  1432 
  1433 The split tactic 3) conceptually simplifies by the following rule:
  1434 
  1435   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  1436 
  1437 Thus any record variable that is bound by meta-all will automatically
  1438 blow up into some record constructor term, consequently the
  1439 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  1440 solve record problems automatically.
  1441 
  1442 
  1443 * reorganized the main HOL image: HOL/Integ and String loaded by
  1444 default; theory Main includes everything;
  1445 
  1446 * automatic simplification of integer sums and comparisons, using cancellation;
  1447 
  1448 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  1449 
  1450 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  1451 
  1452 * many new identities for unions, intersections, set difference, etc.;
  1453 
  1454 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  1455 called split_if, split_split, split_sum_case and split_nat_case (to go
  1456 with add/delsplits);
  1457 
  1458 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  1459 (?x::unit) = (); this is made part of the default simpset, which COULD
  1460 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  1461 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  1462 unit_abs_eta_conv is added in order to counter the effect of
  1463 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  1464 %u.f();
  1465 
  1466 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  1467 makes more sense);
  1468 
  1469 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1470   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1471   disjointness reasoning but breaking a few old proofs.
  1472 
  1473 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  1474 to 'converse' from 'inverse' (for compatibility with ZF and some
  1475 literature);
  1476 
  1477 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  1478 the well-founded relation;
  1479 
  1480 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  1481     Compl A.  The "Compl" syntax remains available as input syntax for this
  1482     release ONLY.
  1483 
  1484 * HOL/Update: new theory of function updates:
  1485     f(a:=b) == %x. if x=a then b else f x
  1486 may also be iterated as in f(a:=b,c:=d,...);
  1487 
  1488 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  1489 
  1490 * HOL/List:
  1491   - new function list_update written xs[i:=v] that updates the i-th
  1492     list position. May also be iterated as in xs[i:=a,j:=b,...].
  1493   - new function `upt' written [i..j(] which generates the list
  1494     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  1495     bound write [i..j], which is a shorthand for [i..j+1(].
  1496   - new lexicographic orderings and corresponding wellfoundedness theorems.
  1497 
  1498 * HOL/Arith:
  1499   - removed 'pred' (predecessor) function;
  1500   - generalized some theorems about n-1;
  1501   - many new laws about "div" and "mod";
  1502   - new laws about greatest common divisors (see theory ex/Primes);
  1503 
  1504 * HOL/Relation: renamed the relational operator r^-1 "converse"
  1505 instead of "inverse";
  1506 
  1507 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  1508   of the multiset ordering;
  1509 
  1510 * directory HOL/Real: a construction of the reals using Dedekind cuts
  1511   (not included by default);
  1512 
  1513 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  1514 
  1515 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  1516   programs, i.e. different program variables may have different types.
  1517 
  1518 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1519   [previously, this check worked only if the rewrite rule was unconditional]
  1520   Now rew can involve either definitions or equalities (either == or =).
  1521 
  1522 
  1523 *** ZF ***
  1524 
  1525 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  1526   only the theorems proved on ZF.ML;
  1527 
  1528 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1529   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1530   disjointness reasoning but breaking a few old proofs.
  1531 
  1532 * ZF/Update: new theory of function updates
  1533     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  1534   may also be iterated as in f(a:=b,c:=d,...);
  1535 
  1536 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  1537 
  1538 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1539   [previously, this check worked only if the rewrite rule was unconditional]
  1540   Now rew can involve either definitions or equalities (either == or =).
  1541 
  1542 * case_tac provided for compatibility with HOL
  1543     (like the old excluded_middle_tac, but with subgoals swapped)
  1544 
  1545 
  1546 *** Internal programming interfaces ***
  1547 
  1548 * Pure: several new basic modules made available for general use, see
  1549 also src/Pure/README;
  1550 
  1551 * improved the theory data mechanism to support encapsulation (data
  1552 kind name replaced by private Object.kind, acting as authorization
  1553 key); new type-safe user interface via functor TheoryDataFun; generic
  1554 print_data function becomes basically useless;
  1555 
  1556 * removed global_names compatibility flag -- all theory declarations
  1557 are qualified by default;
  1558 
  1559 * module Pure/Syntax now offers quote / antiquote translation
  1560 functions (useful for Hoare logic etc. with implicit dependencies);
  1561 see HOL/ex/Antiquote for an example use;
  1562 
  1563 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  1564 cterm -> thm;
  1565 
  1566 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  1567 subgoal;
  1568 
  1569 * Display.print_goals function moved to Locale.print_goals;
  1570 
  1571 * standard print function for goals supports current_goals_markers
  1572 variable for marking begin of proof, end of proof, start of goal; the
  1573 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  1574 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  1575 for example;
  1576 
  1577 
  1578 
  1579 New in Isabelle98 (January 1998)
  1580 --------------------------------
  1581 
  1582 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1583 
  1584 * changed lexical syntax of terms / types: dots made part of long
  1585 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  1586 
  1587 * simpset (and claset) reference variable replaced by functions
  1588 simpset / simpset_ref;
  1589 
  1590 * no longer supports theory aliases (via merge) and non-trivial
  1591 implicit merge of thms' signatures;
  1592 
  1593 * most internal names of constants changed due to qualified names;
  1594 
  1595 * changed Pure/Sequence interface (see Pure/seq.ML);
  1596 
  1597 
  1598 *** General Changes ***
  1599 
  1600 * hierachically structured name spaces (for consts, types, axms, thms
  1601 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  1602 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  1603 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  1604 long_names for fully qualified output names; NOTE: ML programs
  1605 (special tactics, packages etc.) referring to internal names may have
  1606 to be adapted to cope with fully qualified names; in case of severe
  1607 backward campatibility problems try setting 'global_names' at compile
  1608 time to have enrything declared within a flat name space; one may also
  1609 fine tune name declarations in theories via the 'global' and 'local'
  1610 section;
  1611 
  1612 * reimplemented the implicit simpset and claset using the new anytype
  1613 data filed in signatures; references simpset:simpset ref etc. are
  1614 replaced by functions simpset:unit->simpset and
  1615 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  1616 to patch your ML files accordingly;
  1617 
  1618 * HTML output now includes theory graph data for display with Java
  1619 applet or isatool browser; data generated automatically via isatool
  1620 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  1621 
  1622 * defs may now be conditional; improved rewrite_goals_tac to handle
  1623 conditional equations;
  1624 
  1625 * defs now admits additional type arguments, using TYPE('a) syntax;
  1626 
  1627 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  1628 creates a new theory node; implicit merge of thms' signatures is
  1629 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  1630 transfer:theory->thm->thm in (rare) cases;
  1631 
  1632 * improved handling of draft signatures / theories; draft thms (and
  1633 ctyps, cterms) are automatically promoted to real ones;
  1634 
  1635 * slightly changed interfaces for oracles: admit many per theory, named
  1636 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  1637 
  1638 * print_goals: optional output of const types (set show_consts and
  1639 show_types);
  1640 
  1641 * improved output of warnings (###) and errors (***);
  1642 
  1643 * subgoal_tac displays a warning if the new subgoal has type variables;
  1644 
  1645 * removed old README and Makefiles;
  1646 
  1647 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  1648 
  1649 * removed obsolete init_pps and init_database;
  1650 
  1651 * deleted the obsolete tactical STATE, which was declared by
  1652     fun STATE tacfun st = tacfun st st;
  1653 
  1654 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  1655 (which abbreviates $HOME);
  1656 
  1657 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  1658 use isatool fixseq to adapt your ML programs (this works for fully
  1659 qualified references to the Sequence structure only!);
  1660 
  1661 * use_thy no longer requires writable current directory; it always
  1662 reloads .ML *and* .thy file, if either one is out of date;
  1663 
  1664 
  1665 *** Classical Reasoner ***
  1666 
  1667 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  1668 tactics that use classical reasoning to simplify a subgoal without
  1669 splitting it into several subgoals;
  1670 
  1671 * Safe_tac: like safe_tac but uses the default claset;
  1672 
  1673 
  1674 *** Simplifier ***
  1675 
  1676 * added simplification meta rules:
  1677     (asm_)(full_)simplify: simpset -> thm -> thm;
  1678 
  1679 * simplifier.ML no longer part of Pure -- has to be loaded by object
  1680 logics (again);
  1681 
  1682 * added prems argument to simplification procedures;
  1683 
  1684 * HOL, FOL, ZF: added infix function `addsplits':
  1685   instead of `<simpset> setloop (split_tac <thms>)'
  1686   you can simply write `<simpset> addsplits <thms>'
  1687 
  1688 
  1689 *** Syntax ***
  1690 
  1691 * TYPE('a) syntax for type reflection terms;
  1692 
  1693 * no longer handles consts with name "" -- declare as 'syntax' instead;
  1694 
  1695 * pretty printer: changed order of mixfix annotation preference (again!);
  1696 
  1697 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  1698 
  1699 
  1700 *** HOL ***
  1701 
  1702 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1703   with `addloop' of the simplifier to faciliate case splitting in premises.
  1704 
  1705 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  1706 
  1707 * HOL/Auth: new protocol proofs including some for the Internet
  1708   protocol TLS;
  1709 
  1710 * HOL/Map: new theory of `maps' a la VDM;
  1711 
  1712 * HOL/simplifier: simplification procedures nat_cancel_sums for
  1713 cancelling out common nat summands from =, <, <= (in)equalities, or
  1714 differences; simplification procedures nat_cancel_factor for
  1715 cancelling common factor from =, <, <= (in)equalities over natural
  1716 sums; nat_cancel contains both kinds of procedures, it is installed by
  1717 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  1718 
  1719 * HOL/simplifier: terms of the form
  1720   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  1721   are rewritten to
  1722   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  1723   and those of the form
  1724   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  1725   are rewritten to
  1726   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  1727 
  1728 * HOL/datatype
  1729   Each datatype `t' now comes with a theorem `split_t_case' of the form
  1730 
  1731   P(t_case f1 ... fn x) =
  1732      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  1733         ...
  1734        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  1735      )
  1736 
  1737   and a theorem `split_t_case_asm' of the form
  1738 
  1739   P(t_case f1 ... fn x) =
  1740     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  1741         ...
  1742        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  1743      )
  1744   which can be added to a simpset via `addsplits'. The existing theorems
  1745   expand_list_case and expand_option_case have been renamed to
  1746   split_list_case and split_option_case.
  1747 
  1748 * HOL/Arithmetic:
  1749   - `pred n' is automatically converted to `n-1'.
  1750     Users are strongly encouraged not to use `pred' any longer,
  1751     because it will disappear altogether at some point.
  1752   - Users are strongly encouraged to write "0 < n" rather than
  1753     "n ~= 0". Theorems and proof tools have been modified towards this
  1754     `standard'.
  1755 
  1756 * HOL/Lists:
  1757   the function "set_of_list" has been renamed "set" (and its theorems too);
  1758   the function "nth" now takes its arguments in the reverse order and
  1759   has acquired the infix notation "!" as in "xs!n".
  1760 
  1761 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  1762 
  1763 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  1764   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  1765 
  1766 * HOL/record: extensible records with schematic structural subtyping
  1767 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  1768 still lacks various theorems and concrete record syntax;
  1769 
  1770 
  1771 *** HOLCF ***
  1772 
  1773 * removed "axioms" and "generated by" sections;
  1774 
  1775 * replaced "ops" section by extended "consts" section, which is capable of
  1776   handling the continuous function space "->" directly;
  1777 
  1778 * domain package:
  1779   . proves theorems immediately and stores them in the theory,
  1780   . creates hierachical name space,
  1781   . now uses normal mixfix annotations (instead of cinfix...),
  1782   . minor changes to some names and values (for consistency),
  1783   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  1784   . separator between mutual domain defs: changed "," to "and",
  1785   . improved handling of sort constraints;  now they have to
  1786     appear on the left-hand side of the equations only;
  1787 
  1788 * fixed LAM <x,y,zs>.b syntax;
  1789 
  1790 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  1791 adm (%x. P (t x)), where P is chainfinite and t continuous;
  1792 
  1793 
  1794 *** FOL and ZF ***
  1795 
  1796 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1797   with `addloop' of the simplifier to faciliate case splitting in premises.
  1798 
  1799 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  1800 in HOL, they strip ALL and --> from proved theorems;
  1801 
  1802 
  1803 
  1804 New in Isabelle94-8 (May 1997)
  1805 ------------------------------
  1806 
  1807 *** General Changes ***
  1808 
  1809 * new utilities to build / run / maintain Isabelle etc. (in parts
  1810 still somewhat experimental); old Makefiles etc. still functional;
  1811 
  1812 * new 'Isabelle System Manual';
  1813 
  1814 * INSTALL text, together with ./configure and ./build scripts;
  1815 
  1816 * reimplemented type inference for greater efficiency, better error
  1817 messages and clean internal interface;
  1818 
  1819 * prlim command for dealing with lots of subgoals (an easier way of
  1820 setting goals_limit);
  1821 
  1822 
  1823 *** Syntax ***
  1824 
  1825 * supports alternative (named) syntax tables (parser and pretty
  1826 printer); internal interface is provided by add_modesyntax(_i);
  1827 
  1828 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  1829 be used in conjunction with the Isabelle symbol font; uses the
  1830 "symbols" syntax table;
  1831 
  1832 * added token_translation interface (may translate name tokens in
  1833 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  1834 the current print_mode); IMPORTANT: user print translation functions
  1835 are responsible for marking newly introduced bounds
  1836 (Syntax.mark_boundT);
  1837 
  1838 * token translations for modes "xterm" and "xterm_color" that display
  1839 names in bold, underline etc. or colors (which requires a color
  1840 version of xterm);
  1841 
  1842 * infixes may now be declared with names independent of their syntax;
  1843 
  1844 * added typed_print_translation (like print_translation, but may
  1845 access type of constant);
  1846 
  1847 
  1848 *** Classical Reasoner ***
  1849 
  1850 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  1851 some limitations.  Blast_tac...
  1852   + ignores addss, addbefore, addafter; this restriction is intrinsic
  1853   + ignores elimination rules that don't have the correct format
  1854         (the conclusion MUST be a formula variable)
  1855   + ignores types, which can make HOL proofs fail
  1856   + rules must not require higher-order unification, e.g. apply_type in ZF
  1857     [message "Function Var's argument not a bound variable" relates to this]
  1858   + its proof strategy is more general but can actually be slower
  1859 
  1860 * substitution with equality assumptions no longer permutes other
  1861 assumptions;
  1862 
  1863 * minor changes in semantics of addafter (now called addaltern); renamed
  1864 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  1865 (and access functions for it);
  1866 
  1867 * improved combination of classical reasoner and simplifier:
  1868   + functions for handling clasimpsets
  1869   + improvement of addss: now the simplifier is called _after_ the
  1870     safe steps.
  1871   + safe variant of addss called addSss: uses safe simplifications
  1872     _during_ the safe steps. It is more complete as it allows multiple
  1873     instantiations of unknowns (e.g. with slow_tac).
  1874 
  1875 *** Simplifier ***
  1876 
  1877 * added interface for simplification procedures (functions that
  1878 produce *proven* rewrite rules on the fly, depending on current
  1879 redex);
  1880 
  1881 * ordering on terms as parameter (used for ordered rewriting);
  1882 
  1883 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  1884 
  1885 * the solver is now split into a safe and an unsafe part.
  1886 This should be invisible for the normal user, except that the
  1887 functions setsolver and addsolver have been renamed to setSolver and
  1888 addSolver; added safe_asm_full_simp_tac;
  1889 
  1890 
  1891 *** HOL ***
  1892 
  1893 * a generic induction tactic `induct_tac' which works for all datatypes and
  1894 also for type `nat';
  1895 
  1896 * a generic case distinction tactic `exhaust_tac' which works for all
  1897 datatypes and also for type `nat';
  1898 
  1899 * each datatype comes with a function `size';
  1900 
  1901 * patterns in case expressions allow tuple patterns as arguments to
  1902 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  1903 
  1904 * primrec now also works with type nat;
  1905 
  1906 * recdef: a new declaration form, allows general recursive functions to be
  1907 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  1908 
  1909 * the constant for negation has been renamed from "not" to "Not" to
  1910 harmonize with FOL, ZF, LK, etc.;
  1911 
  1912 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  1913 infinite lists;
  1914 
  1915 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  1916 
  1917 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  1918 problems in commutative rings, using axiomatic type classes for + and *;
  1919 
  1920 * more examples in HOL/MiniML and HOL/Auth;
  1921 
  1922 * more default rewrite rules for quantifiers, union/intersection;
  1923 
  1924 * a new constant `arbitrary == @x.False';
  1925 
  1926 * HOLCF/IOA replaces old HOL/IOA;
  1927 
  1928 * HOLCF changes: derived all rules and arities
  1929   + axiomatic type classes instead of classes
  1930   + typedef instead of faking type definitions
  1931   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  1932   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  1933   + eliminated the types void, one, tr
  1934   + use unit lift and bool lift (with translations) instead of one and tr
  1935   + eliminated blift from Lift3.thy (use Def instead of blift)
  1936   all eliminated rules are derived as theorems --> no visible changes ;
  1937 
  1938 
  1939 *** ZF ***
  1940 
  1941 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  1942 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  1943 as ZF_cs addSIs [equalityI];
  1944 
  1945 
  1946 
  1947 New in Isabelle94-7 (November 96)
  1948 ---------------------------------
  1949 
  1950 * allowing negative levels (as offsets) in prlev and choplev;
  1951 
  1952 * super-linear speedup for large simplifications;
  1953 
  1954 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  1955 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  1956 FAIL); can suppress it using the command Delsimps (ex_simps @
  1957 all_simps); De Morgan laws are also now included, by default;
  1958 
  1959 * improved printing of ==>  :  ~:
  1960 
  1961 * new object-logic "Sequents" adds linear logic, while replacing LK
  1962 and Modal (thanks to Sara Kalvala);
  1963 
  1964 * HOL/Auth: correctness proofs for authentication protocols;
  1965 
  1966 * HOL: new auto_tac combines rewriting and classical reasoning (many
  1967 examples on HOL/Auth);
  1968 
  1969 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  1970 the rewriter and classical reasoner simultaneously;
  1971 
  1972 * function uresult no longer returns theorems in "standard" format;
  1973 regain previous version by: val uresult = standard o uresult;
  1974 
  1975 
  1976 
  1977 New in Isabelle94-6
  1978 -------------------
  1979 
  1980 * oracles -- these establish an interface between Isabelle and trusted
  1981 external reasoners, which may deliver results as theorems;
  1982 
  1983 * proof objects (in particular record all uses of oracles);
  1984 
  1985 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  1986 
  1987 * "constdefs" section in theory files;
  1988 
  1989 * "primrec" section (HOL) no longer requires names;
  1990 
  1991 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  1992 
  1993 
  1994 
  1995 New in Isabelle94-5
  1996 -------------------
  1997 
  1998 * reduced space requirements;
  1999 
  2000 * automatic HTML generation from theories;
  2001 
  2002 * theory files no longer require "..." (quotes) around most types;
  2003 
  2004 * new examples, including two proofs of the Church-Rosser theorem;
  2005 
  2006 * non-curried (1994) version of HOL is no longer distributed;
  2007 
  2008 
  2009 
  2010 New in Isabelle94-4
  2011 -------------------
  2012 
  2013 * greatly reduced space requirements;
  2014 
  2015 * theory files (.thy) no longer require \...\ escapes at line breaks;
  2016 
  2017 * searchable theorem database (see the section "Retrieving theorems" on
  2018 page 8 of the Reference Manual);
  2019 
  2020 * new examples, including Grabczewski's monumental case study of the
  2021 Axiom of Choice;
  2022 
  2023 * The previous version of HOL renamed to Old_HOL;
  2024 
  2025 * The new version of HOL (previously called CHOL) uses a curried syntax
  2026 for functions.  Application looks like f a b instead of f(a,b);
  2027 
  2028 * Mutually recursive inductive definitions finally work in HOL;
  2029 
  2030 * In ZF, pattern-matching on tuples is now available in all abstractions and
  2031 translates to the operator "split";
  2032 
  2033 
  2034 
  2035 New in Isabelle94-3
  2036 -------------------
  2037 
  2038 * new infix operator, addss, allowing the classical reasoner to
  2039 perform simplification at each step of its search.  Example:
  2040         fast_tac (cs addss ss)
  2041 
  2042 * a new logic, CHOL, the same as HOL, but with a curried syntax
  2043 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  2044 look like (a,b) instead of <a,b>;
  2045 
  2046 * PLEASE NOTE: CHOL will eventually replace HOL!
  2047 
  2048 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  2049 It translates to the operator "split".  A new theory of integers is available;
  2050 
  2051 * In ZF, integer numerals now denote two's-complement binary integers.
  2052 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  2053 
  2054 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  2055 of the Axiom of Choice;
  2056 
  2057 
  2058 
  2059 New in Isabelle94-2
  2060 -------------------
  2061 
  2062 * Significantly faster resolution;
  2063 
  2064 * the different sections in a .thy file can now be mixed and repeated
  2065 freely;
  2066 
  2067 * Database of theorems for FOL, HOL and ZF.  New
  2068 commands including qed, qed_goal and bind_thm store theorems in the database.
  2069 
  2070 * Simple database queries: return a named theorem (get_thm) or all theorems of
  2071 a given theory (thms_of), or find out what theory a theorem was proved in
  2072 (theory_of_thm);
  2073 
  2074 * Bugs fixed in the inductive definition and datatype packages;
  2075 
  2076 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  2077 and HOL_dup_cs obsolete;
  2078 
  2079 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  2080 have been removed;
  2081 
  2082 * Simpler definition of function space in ZF;
  2083 
  2084 * new results about cardinal and ordinal arithmetic in ZF;
  2085 
  2086 * 'subtype' facility in HOL for introducing new types as subsets of existing
  2087 types;
  2088 
  2089 
  2090 $Id$