NEWS
 author wenzelm Fri Jan 11 00:27:40 2002 +0100 (2002-01-11) changeset 12707 4013be8572c5 parent 12690 ac3fa7c05e5a child 12724 beedc794bd67 permissions -rw-r--r--
* Pure: localized 'lemmas', 'theorems', 'declare';
     1

     2 Isabelle NEWS -- history user-relevant changes

     3 ==============================================

     4

     5 New in Isabelle2001 (December 2001)

     6 -----------------------------------

     7

     8 *** Document preparation ***

     9

    10 * greatly simplified document preparation setup, including more

    11 graceful interpretation of isatool usedir -i/-d/-D options, and more

    12 instructive isatool mkdir; users should basically be able to get

    13 started with "isatool mkdir Test && isatool make";

    14

    15 * theory dependency graph may now be incorporated into documents;

    16 isatool usedir -g true will produce session_graph.eps/.pdf for use

    17 with \includegraphics of LaTeX;

    18

    19 * proper spacing of consecutive markup elements, especially text

    20 blocks after section headings;

    21

    22 * support bold style (for single symbols only), input syntax is like

    23 this: "\<^bold>\<alpha>" or "\<^bold>A";

    24

    25 * \<bullet> is now output as bold \cdot by default, which looks much

    26 better in printed text;

    27

    28 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;

    29 note that these symbols are currently unavailable in Proof General /

    30 X-Symbol; added \<euro> symbol;

    31

    32 * isatool latex no longer depends on changed TEXINPUTS, instead

    33 isatool document copies the Isabelle style files to the target

    34 location;

    35

    36

    37 *** Isar ***

    38

    39 * Pure/Provers: improved proof by cases and induction;

    40   - 'case' command admits impromptu naming of parameters (such as

    41     "case (Suc n)");

    42   - 'induct' method divinates rule instantiation from the inductive

    43     claim; no longer requires excessive ?P bindings for proper

    44     instantiation of cases;

    45   - 'induct' method properly enumerates all possibilities of set/type

    46     rules; as a consequence facts may be also passed through *type*

    47     rules without further ado;

    48   - 'induct' method now derives symbolic cases from the *rulified*

    49     rule (before it used to rulify cases stemming from the internal

    50     atomized version); this means that the context of a non-atomic

    51     statement becomes is included in the hypothesis, avoiding the

    52     slightly cumbersome show "PROP ?case" form;

    53   - 'induct' may now use elim-style induction rules without chaining

    54     facts, using missing'' premises from the goal state; this allows

    55     rules stemming from inductive sets to be applied in unstructured

    56     scripts, while still benefitting from proper handling of non-atomic

    57     statements; NB: major inductive premises need to be put first, all

    58     the rest of the goal is passed through the induction;

    59   - 'induct' proper support for mutual induction involving non-atomic

    60     rule statements (uses the new concept of simultaneous goals, see

    61     below);

    62   - removed obsolete "(simplified)" and "(stripped)" options of methods;

    63   - added 'print_induct_rules' (covered by help item in Proof General > 3.3);

    64   - moved induct/cases attributes to Pure, methods to Provers;

    65   - generic method setup instantiated for FOL and HOL;

    66

    67 * Pure: support multiple simultaneous goal statements, for example

    68 "have a: A and b: B" (same for 'theorem' etc.); being a pure

    69 meta-level mechanism, this acts as if several individual goals had

    70 been stated separately; in particular common proof methods need to be

    71 repeated in order to cover all claims; note that a single elimination

    72 step is *not* sufficient to establish the two conjunctions, so this

    73 fails:

    74

    75   assume "A & B" then have A and B ..   (*".." fails*)

    76

    77 better use "obtain" in situations as above; alternative refer to

    78 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;

    79

    80 * Pure: proper integration with locales''; unlike the original

    81 version by Florian Kammüller, Isar locales package high-level proof

    82 contexts rather than raw logical ones (e.g. we admit to include

    83 attributes everywhere); operations on locales include merge and

    84 rename; e.g. see HOL/ex/Locales.thy;

    85

    86 * Pure: the following commands have been localized'', supporting a

    87 target locale specification "(in name)": 'lemma', 'theorem',

    88 'corollary', 'lemmas', 'theorems', 'declare'; the results will be

    89 stored both within the locale and at the theory level (exported and

    90 qualified by the locale name);

    91

    92 * Pure: theory goals now support ad-hoc contexts, which are discharged

    93 in the result, as in lemma (assumes A and B) K: A .''; syntax

    94 coincides with that of a locale body;

    95

    96 * Pure: renamed "antecedent" case to "rule_context";

    97

    98 * Pure: added 'corollary' command;

    99

   100 * Pure: fixed 'token_translation' command;

   101

   102 * Pure: removed obsolete 'exported' attribute;

   103

   104 * Pure: dummy pattern "_" in is/let is now automatically lifted over

   105 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")

   106 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");

   107

   108 * Pure: method 'atomize' presents local goal premises as object-level

   109 statements (atomic meta-level propositions); setup controlled via

   110 rewrite rules declarations of 'atomize' attribute; example

   111 application: 'induct' method with proper rule statements in improper

   112 proof *scripts*;

   113

   114 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)

   115 now consider the syntactic context of assumptions, giving a better

   116 chance to get type-inference of the arguments right (this is

   117 especially important for locales);

   118

   119 * Pure: "sorry" no longer requires quick_and_dirty in interactive

   120 mode;

   121

   122 * Pure/obtain: the formal conclusion "thesis", being marked as

   123 internal'', may no longer be reference directly in the text;

   124 potential INCOMPATIBILITY, may need to use "?thesis" in rare

   125 situations;

   126

   127 * Pure: generic 'sym' attribute which declares a rule both as pure

   128 'elim?' and for the 'symmetric' operation;

   129

   130 * Pure/Provers/classical: simplified integration with pure rule

   131 attributes and methods; the classical "intro?/elim?/dest?"

   132 declarations coincide with the pure ones; the "rule" method no longer

   133 includes classically swapped intros; "intro" and "elim" methods no

   134 longer pick rules from the context; also got rid of ML declarations

   135 AddXIs/AddXEs/AddXDs; all of this has some potential for

   136 INCOMPATIBILITY;

   137

   138 * Provers/classical: attribute 'swapped' produces classical inversions

   139 of introduction rules;

   140

   141 * Provers/simplifier: 'simplified' attribute may refer to explicit

   142 rules instead of full simplifier context; 'iff' attribute handles

   143 conditional rules;

   144

   145 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;

   146

   147 * HOL: 'recdef' now fails on unfinished automated proofs, use

   148 "(permissive)" option to recover old behavior;

   149

   150 * HOL: 'inductive' no longer features separate (collective) attributes

   151 for 'intros' (was found too confusing);

   152

   153 * HOL: properly declared induction rules less_induct and

   154 wf_induct_rule;

   155

   156

   157 *** HOL ***

   158

   159 * HOL: moved over to sane numeral syntax; the new policy is as

   160 follows:

   161

   162   - 0 and 1 are polymorphic constants, which are defined on any

   163   numeric type (nat, int, real etc.);

   164

   165   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based

   166   binary representation internally;

   167

   168   - type nat has special constructor Suc, and generally prefers Suc 0

   169   over 1::nat and Suc (Suc 0) over 2::nat;

   170

   171 This change may cause significant problems of INCOMPATIBILITY; here

   172 are some hints on converting existing sources:

   173

   174   - due to the new "num" token, "-0" and "-1" etc. are now atomic

   175   entities, so expressions involving "-" (unary or binary minus) need

   176   to be spaced properly;

   177

   178   - existing occurrences of "1" may need to be constraint "1::nat" or

   179   even replaced by Suc 0; similar for old "2";

   180

   181   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";

   182

   183   - remove all special provisions on numerals in proofs;

   184

   185 * HOL: the class of all HOL types is now called "type" rather than

   186 "term"; INCOMPATIBILITY, need to adapt references to this type class

   187 in axclass/classes, instance/arities, and (usually rare) occurrences

   188 in typings (of consts etc.); internally the class is called

   189 "HOL.type", ML programs should refer to HOLogic.typeS;

   190

   191 * HOL/record package improvements:

   192   - new derived operations "fields" to build a partial record section,

   193     "extend" to promote a fixed record to a record scheme, and

   194     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*

   195     declared as simp by default;

   196   - shared operations ("more", "fields", etc.) now need to be always

   197     qualified) --- potential INCOMPATIBILITY;

   198   - removed "make_scheme" operations (use "make" with "extend") --

   199     INCOMPATIBILITY;

   200   - removed "more" class (simply use "term") -- INCOMPATIBILITY;

   201   - provides cases/induct rules for use with corresponding Isar

   202     methods (for concrete records, record schemes, concrete more

   203     parts, and schematic more parts -- in that order);

   204   - internal definitions directly based on a light-weight abstract

   205     theory of product types over typedef rather than datatype;

   206

   207 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);

   208

   209 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"

   210 (beware of argument permutation!);

   211

   212 * HOL: linorder_less_split superseded by linorder_cases;

   213

   214 * HOL: added "The" definite description operator; move Hilbert's "Eps"

   215 to peripheral theory "Hilbert_Choice";

   216

   217 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so

   218 in this (rare) case use:

   219

   220   delSWrapper "split_all_tac"

   221   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)

   222

   223 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS

   224 MAY FAIL;

   225

   226 * HOL: introduced f^n = f o ... o f; warning: due to the limits of

   227 Isabelle's type classes, ^ on functions and relations has too general

   228 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be

   229 necessary to attach explicit type constraints;

   230

   231 * HOL/Relation: the prefix name of the infix "O" has been changed from "comp"

   232 to "rel_comp"; INCOMPATIBILITY: a few theorems have been renamed accordingly

   233 (eg "compI" -> "rel_compI").

   234

   235 * HOL: syntax translations now work properly with numerals and records

   236 expressions;

   237

   238 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead

   239 of "lam" -- INCOMPATIBILITY;

   240

   241 * HOL: got rid of some global declarations (potential INCOMPATIBILITY

   242 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"

   243 renamed "Product_Type.unit";

   244

   245 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl

   246

   247 * HOL/GroupTheory: group theory examples including Sylow's theorem (by

   248 Florian Kammüller);

   249

   250 * HOL/IMP: updated and converted to new-style theory format; several

   251 parts turned into readable document, with proper Isar proof texts and

   252 some explanations (by Gerwin Klein);

   253

   254 * HOL-Hyperreal is now a logic image;

   255

   256

   257 *** HOLCF ***

   258

   259 * Isar: consts/constdefs supports mixfix syntax for continuous

   260 operations;

   261

   262 * Isar: domain package adapted to new-style theory format, e.g. see

   263 HOLCF/ex/Dnat.thy;

   264

   265 * theory Lift: proper use of rep_datatype lift instead of ML hacks --

   266 potential INCOMPATIBILITY; now use plain induct_tac instead of former

   267 lift.induct_tac, always use UU instead of Undef;

   268

   269 * HOLCF/IMP: updated and converted to new-style theory;

   270

   271

   272 *** ZF ***

   273

   274 * Isar: proper integration of logic-specific tools and packages,

   275 including theory commands '(co)inductive', '(co)datatype',

   276 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',

   277 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');

   278

   279 * theory Main no longer includes AC; for the Axiom of Choice, base

   280 your theory on Main_ZFC;

   281

   282 * the integer library now covers quotients and remainders, with many

   283 laws relating division to addition, multiplication, etc.;

   284

   285 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a

   286 typeless version of the formalism;

   287

   288 * ZF/IMP: updated and converted to new-style theory format;

   289

   290 * ZF/Induct: new directory for examples of inductive definitions,

   291 including theory Multiset for multiset orderings; converted to

   292 new-style theory format;

   293

   294

   295 *** General ***

   296

   297 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference

   298 variable proof controls level of detail: 0 = no proofs (only oracle

   299 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see

   300 also ref manual for further ML interfaces;

   301

   302 * Pure/axclass: removed obsolete ML interface

   303 goal_subclass/goal_arity;

   304

   305 * Pure/syntax: new token syntax "num" for plain numerals (without "#"

   306 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now

   307 separate tokens, so expressions involving minus need to be spaced

   308 properly;

   309

   310 * Pure/syntax: support non-oriented infixes, using keyword "infix"

   311 rather than "infixl" or "infixr";

   312

   313 * Pure/syntax: concrete syntax for dummy type variables admits genuine

   314 sort constraint specifications in type inference; e.g. "x::_::foo"

   315 ensures that the type of "x" is of sort "foo" (but not necessarily a

   316 type variable);

   317

   318 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"

   319 control output of nested => (types); the default behavior is

   320 "type_brackets";

   321

   322 * Pure/syntax: builtin parse translation for "_constify" turns valued

   323 tokens into AST constants;

   324

   325 * Pure/syntax: prefer later declarations of translations and print

   326 translation functions; potential INCOMPATIBILITY: need to reverse

   327 multiple declarations for same syntax element constant;

   328

   329 * Provers/classical: renamed addaltern to addafter, addSaltern to

   330 addSafter;

   331

   332 * Provers/clasimp: iff'' declarations now handle conditional rules

   333 as well;

   334

   335 * system: tested support for MacOS X; should be able to get Isabelle +

   336 Proof General to work in a plain Terminal after installing Poly/ML

   337 (e.g. from the Isabelle distribution area) and GNU bash alone

   338 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol

   339 support requires further installations, e.g. from

   340 http://fink.sourceforge.net/);

   341

   342 * system: support Poly/ML 4.1.1 (able to manage larger heaps);

   343

   344 * system: Proof General keywords specification is now part of the

   345 Isabelle distribution (see etc/isar-keywords.el);

   346

   347 * system: some support for persistent Proof General sessions (refrain

   348 from outdating all loaded theories on startup);

   349

   350 * system: smart selection of Isabelle process versus Isabelle

   351 interface, accommodates case-insensitive file systems (e.g. HFS+); may

   352 run both "isabelle" and "Isabelle" even if file names are badly

   353 damaged (executable inspects the case of the first letter of its own

   354 name); added separate "isabelle-process" and "isabelle-interface";

   355

   356 * system: refrain from any attempt at filtering input streams; no

   357 longer support 8bit'' encoding of old isabelle font, instead proper

   358 iso-latin characters may now be used; the related isatools

   359 "symbolinput" and "nonascii" have disappeared as well;

   360

   361 * system: removed old "xterm" interface (the print modes "xterm" and

   362 "xterm_color" are still available for direct use in a suitable

   363 terminal);

   364

   365

   366

   367 New in Isabelle99-2 (February 2001)

   368 -----------------------------------

   369

   370 *** Overview of INCOMPATIBILITIES ***

   371

   372 * HOL: please note that theories in the Library and elsewhere often use the

   373 new-style (Isar) format; to refer to their theorems in an ML script you must

   374 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";

   375

   376 * HOL: inductive package no longer splits induction rule aggressively,

   377 but only as far as specified by the introductions given; the old

   378 format may be recovered via ML function complete_split_rule or attribute

   379 'split_rule (complete)';

   380

   381 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,

   382 gfp_Tarski to gfp_unfold;

   383

   384 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;

   385

   386 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a

   387 relation); infix "^^" has been renamed ""; infix "" has been

   388 renamed ""; "univalent" has been renamed "single_valued";

   389

   390 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"

   391 operation;

   392

   393 * HOLCF: infix "" has been renamed "$"; the symbol syntax is \<cdot>;   394   395 * Isar: 'obtain' no longer declares "that" fact as simp/intro;   396   397 * Isar/HOL: method 'induct' now handles non-atomic goals; as a   398 consequence, it is no longer monotonic wrt. the local goal context   399 (which is now passed through the inductive cases);   400   401 * Document preparation: renamed standard symbols \<ll> to \<lless> and   402 \<gg> to \<ggreater>;   403   404   405 *** Document preparation ***   406   407 * \isabellestyle{NAME} selects version of Isabelle output (currently   408 available: are "it" for near math-mode best-style output, "sl" for   409 slanted text style, and "tt" for plain type-writer; if no   410 \isabellestyle command is given, output is according to slanted   411 type-writer);   412   413 * support sub/super scripts (for single symbols only), input syntax is   414 like this: "A\<^sup>*" or "A\<^sup>\<star>";   415   416 * some more standard symbols; see Appendix A of the system manual for   417 the complete list of symbols defined in isabellesym.sty;   418   419 * improved isabelle style files; more abstract symbol implementation   420 (should now use \isamath{...} and \isatext{...} in custom symbol   421 definitions);   422   423 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals   424 state; Note that presentation of goal states does not conform to   425 actual human-readable proof documents. Please do not include goal   426 states into document output unless you really know what you are doing!   427   428 * proper indentation of antiquoted output with proportional LaTeX   429 fonts;   430   431 * no_document ML operator temporarily disables LaTeX document   432 generation;   433   434 * isatool unsymbolize tunes sources for plain ASCII communication;   435   436   437 *** Isar ***   438   439 * Pure: Isar now suffers initial goal statements to contain unbound   440 schematic variables (this does not conform to actual readable proof   441 documents, due to unpredictable outcome and non-compositional proof   442 checking); users who know what they are doing may use schematic goals   443 for Prolog-style synthesis of proven results;   444   445 * Pure: assumption method (an implicit finishing) now handles actual   446 rules as well;   447   448 * Pure: improved 'obtain' --- moved to Pure, insert "that" into   449 initial goal, declare "that" only as Pure intro (only for single   450 steps); the "that" rule assumption may now be involved in implicit   451 finishing, thus ".." becomes a feasible for trivial obtains;   452   453 * Pure: default proof step now includes 'intro_classes'; thus trivial   454 instance proofs may be performed by "..";   455   456 * Pure: ?thesis / ?this / "..." now work for pure meta-level   457 statements as well;   458   459 * Pure: more robust selection of calculational rules;   460   461 * Pure: the builtin notion of 'finished' goal now includes the ==-refl   462 rule (as well as the assumption rule);   463   464 * Pure: 'thm_deps' command visualizes dependencies of theorems and   465 lemmas, using the graph browser tool;   466   467 * Pure: predict failure of "show" in interactive mode;   468   469 * Pure: 'thms_containing' now takes actual terms as arguments;   470   471 * HOL: improved method 'induct' --- now handles non-atomic goals   472 (potential INCOMPATIBILITY); tuned error handling;   473   474 * HOL: cases and induct rules now provide explicit hints about the   475 number of facts to be consumed (0 for "type" and 1 for "set" rules);   476 any remaining facts are inserted into the goal verbatim;   477   478 * HOL: local contexts (aka cases) may now contain term bindings as   479 well; the 'cases' and 'induct' methods new provide a ?case binding for   480 the result to be shown in each case;   481   482 * HOL: added 'recdef_tc' command;   483   484 * isatool convert assists in eliminating legacy ML scripts;   485   486   487 *** HOL ***   488   489 * HOL/Library: a collection of generic theories to be used together   490 with main HOL; the theory loader path already includes this directory   491 by default; the following existing theories have been moved here:   492 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While   493 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);   494   495 * HOL/Unix: "Some aspects of Unix file-system security", a typical   496 modelling and verification task performed in Isabelle/HOL +   497 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).   498   499 * HOL/Algebra: special summation operator SUM no longer exists, it has   500 been replaced by setsum; infix 'assoc' now has priority 50 (like   501 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to   502 'domain', this makes the theory consistent with mathematical   503 literature;   504   505 * HOL basics: added overloaded operations "inverse" and "divide"   506 (infix "/"), syntax for generic "abs" operation, generic summation   507 operator \<Sum>;   508   509 * HOL/typedef: simplified package, provide more useful rules (see also   510 HOL/subset.thy);   511   512 * HOL/datatype: induction rule for arbitrarily branching datatypes is   513 now expressed as a proper nested rule (old-style tactic scripts may   514 require atomize_strip_tac to cope with non-atomic premises);   515   516 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule   517 to "split_conv" (old name still available for compatibility);   518   519 * HOL: improved concrete syntax for strings (e.g. allows translation   520 rules with string literals);   521   522 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals   523 and Fleuriot's mechanization of analysis, including the transcendental   524 functions for the reals;   525   526 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;   527   528   529 *** CTT ***   530   531 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that   532 "lam" is displayed as TWO lambda-symbols   533   534 * CTT: theory Main now available, containing everything (that is, Bool   535 and Arith);   536   537   538 *** General ***   539   540 * Pure: the Simplifier has been implemented properly as a derived rule   541 outside of the actual kernel (at last!); the overall performance   542 penalty in practical applications is about 50%, while reliability of   543 the Isabelle inference kernel has been greatly improved;   544   545 * print modes "brackets" and "no_brackets" control output of nested =>   546 (types) and ==> (props); the default behaviour is "brackets";   547   548 * Provers: fast_tac (and friends) now handle actual object-logic rules   549 as assumptions as well;   550   551 * system: support Poly/ML 4.0;   552   553 * system: isatool install handles KDE version 1 or 2;   554   555   556   557 New in Isabelle99-1 (October 2000)   558 ----------------------------------   559   560 *** Overview of INCOMPATIBILITIES ***   561   562 * HOL: simplification of natural numbers is much changed; to partly   563 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)   564 issue the following ML commands:   565   566 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;   567 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];   568   569 * HOL: simplification no longer dives into case-expressions; this is   570 controlled by "t.weak_case_cong" for each datatype t;   571   572 * HOL: nat_less_induct renamed to less_induct;   573   574 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool   575 fixsome to patch .thy and .ML sources automatically;   576   577 select_equality -> some_equality   578 select_eq_Ex -> some_eq_ex   579 selectI2EX -> someI2_ex   580 selectI2 -> someI2   581 selectI -> someI   582 select1_equality -> some1_equality   583 Eps_sym_eq -> some_sym_eq_trivial   584 Eps_eq -> some_eq_trivial   585   586 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;   587   588 * HOL: removed obsolete theorem binding expand_if (refer to split_if   589 instead);   590   591 * HOL: the recursion equations generated by 'recdef' are now called   592 f.simps instead of f.rules;   593   594 * HOL: qed_spec_mp now also handles bounded ALL as well;   595   596 * HOL: 0 is now overloaded, so the type constraint ":: nat" may   597 sometimes be needed;   598   599 * HOL: the constant for "fx" is now "image" rather than "op ";   600   601 * HOL: the constant for "f-x" is now "vimage" rather than "op -";   602   603 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian   604 product is now "<*>" instead of "Times"; the lexicographic product is   605 now "<*lex*>" instead of "**";   606   607 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part   608 of main HOL, but was unused); better use HOL's datatype package;   609   610 * HOL: removed "symbols" syntax for constant "override" of theory Map;   611 the old syntax may be recovered as follows:   612   613 syntax (symbols)   614 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"   615 (infixl "\\<oplus>" 100)   616   617 * HOL/Real: "rabs" replaced by overloaded "abs" function;   618   619 * HOL/ML: even fewer consts are declared as global (see theories Ord,   620 Lfp, Gfp, WF); this only affects ML packages that refer to const names   621 internally;   622   623 * HOL and ZF: syntax for quotienting wrt an equivalence relation   624 changed from A/r to A//r;   625   626 * ZF: new treatment of arithmetic (nat & int) may break some old   627 proofs;   628   629 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,   630 rulify -> rule_format, elimify -> elim_format, ...);   631   632 * Isar/Provers: intro/elim/dest attributes changed; renamed   633 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one   634 should have to change intro!! to intro? only); replaced "delrule" by   635 "rule del";   636   637 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;   638   639 * Provers: strengthened force_tac by using new first_best_tac;   640   641 * LaTeX document preparation: several changes of isabelle.sty (see   642 lib/texinputs);   643   644   645 *** Document preparation ***   646   647 * formal comments (text blocks etc.) in new-style theories may now   648 contain antiquotations of thm/prop/term/typ/text to be presented   649 according to latex print mode; concrete syntax is like this:   650 @{term[show_types] "f(x) = a + x"};   651   652 * isatool mkdir provides easy setup of Isabelle session directories,   653 including proper document sources;   654   655 * generated LaTeX sources are now deleted after successful run   656 (isatool document -c); may retain a copy somewhere else via -D option   657 of isatool usedir;   658   659 * isatool usedir -D now lets isatool latex -o sty update the Isabelle   660 style files, achieving self-contained LaTeX sources and simplifying   661 LaTeX debugging;   662   663 * old-style theories now produce (crude) LaTeX output as well;   664   665 * browser info session directories are now self-contained (may be put   666 on WWW server seperately); improved graphs of nested sessions; removed   667 graph for 'all sessions';   668   669 * several improvements in isabelle style files; \isabellestyle{it}   670 produces fake math mode output; \isamarkupheader is now \section by   671 default; see lib/texinputs/isabelle.sty etc.;   672   673   674 *** Isar ***   675   676 * Isar/Pure: local results and corresponding term bindings are now   677 subject to Hindley-Milner polymorphism (similar to ML); this   678 accommodates incremental type-inference very nicely;   679   680 * Isar/Pure: new derived language element 'obtain' supports   681 generalized existence reasoning;   682   683 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'   684 support accumulation of results, without applying any rules yet;   685 useful to collect intermediate results without explicit name   686 references, and for use with transitivity rules with more than 2   687 premises;   688   689 * Isar/Pure: scalable support for case-analysis type proofs: new   690 'case' language element refers to local contexts symbolically, as   691 produced by certain proof methods; internally, case names are attached   692 to theorems as "tags";   693   694 * Isar/Pure: theory command 'hide' removes declarations from   695 class/type/const name spaces;   696   697 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to   698 indicate potential overloading;   699   700 * Isar/Pure: changed syntax of local blocks from {{ }} to { };   701   702 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write   703 "{a,b,c}" instead of {a,b,c};   704   705 * Isar/Pure now provides its own version of intro/elim/dest   706 attributes; useful for building new logics, but beware of confusion   707 with the version in Provers/classical;   708   709 * Isar/Pure: the local context of (non-atomic) goals is provided via   710 case name 'antecedent';   711   712 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms   713 to the current context is now done automatically);   714   715 * Isar/Pure: theory command 'method_setup' provides a simple interface   716 for definining proof methods in ML;   717   718 * Isar/Provers: intro/elim/dest attributes changed; renamed   719 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in   720 most cases, one should have to change intro!! to intro? only);   721 replaced "delrule" by "rule del";   722   723 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and   724 'symmetric' attribute (the latter supercedes [RS sym]);   725   726 * Isar/Provers: splitter support (via 'split' attribute and 'simp'   727 method modifier); 'simp' method: 'only:' modifier removes loopers as   728 well (including splits);   729   730 * Isar/Provers: Simplifier and Classical methods now support all kind   731 of modifiers used in the past, including 'cong', 'iff', etc.   732   733 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination   734 of Simplifier and Classical reasoner);   735   736 * Isar/HOL: new proof method 'cases' and improved version of 'induct'   737 now support named cases; major packages (inductive, datatype, primrec,   738 recdef) support case names and properly name parameters;   739   740 * Isar/HOL: new transitivity rules for substitution in inequalities --   741 monotonicity conditions are extracted to be proven at end of   742 calculations;   743   744 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof   745 method anyway;   746   747 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =   748 split_if split_if_asm; datatype package provides theorems foo.splits =   749 foo.split foo.split_asm for each datatype;   750   751 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"   752 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof   753 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:   754 use "(cases (simplified))" method in proper proof texts);   755   756 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;   757   758 * Isar: names of theorems etc. may be natural numbers as well;   759   760 * Isar: 'pr' command: optional arguments for goals_limit and   761 ProofContext.prems_limit; no longer prints theory contexts, but only   762 proof states;   763   764 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit   765 additional print modes to be specified; e.g. "pr(latex)" will print   766 proof state according to the Isabelle LaTeX style;   767   768 * Isar: improved support for emulating tactic scripts, including proof   769 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',   770 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'   771 (for HOL datatypes);   772   773 * Isar: simplified (more robust) goal selection of proof methods: 1st   774 goal, all goals, or explicit goal specifier (tactic emulation); thus   775 'proof method scripts' have to be in depth-first order;   776   777 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';   778   779 * Isar: removed 'help' command, which hasn't been too helpful anyway;   780 should instead use individual commands for printing items   781 (print_commands, print_methods etc.);   782   783 * Isar: added 'nothing' --- the empty list of theorems;   784   785   786 *** HOL ***   787   788 * HOL/MicroJava: formalization of a fragment of Java, together with a   789 corresponding virtual machine and a specification of its bytecode   790 verifier and a lightweight bytecode verifier, including proofs of   791 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and   792 Cornelia Pusch (see also the homepage of project Bali at   793 http://isabelle.in.tum.de/Bali/);   794   795 * HOL/Algebra: new theory of rings and univariate polynomials, by   796 Clemens Ballarin;   797   798 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese   799 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M   800 Rasmussen;   801   802 * HOL/Lattice: fundamental concepts of lattice theory and order   803 structures, including duals, properties of bounds versus algebraic   804 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski   805 Theorem for complete lattices etc.; may also serve as a demonstration   806 for abstract algebraic reasoning using axiomatic type classes, and   807 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;   808   809 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David   810 von Oheimb;   811   812 * HOL/IMPP: extension of IMP with local variables and mutually   813 recursive procedures, by David von Oheimb;   814   815 * HOL/Lambda: converted into new-style theory and document;   816   817 * HOL/ex/Multiquote: example of multiple nested quotations and   818 anti-quotations -- basically a generalized version of de-Bruijn   819 representation; very useful in avoiding lifting of operations;   820   821 * HOL/record: added general record equality rule to simpset; fixed   822 select-update simplification procedure to handle extended records as   823 well; admit "r" as field name;   824   825 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with   826 other numeric types and also as the identity of groups, rings, etc.;   827   828 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.   829 Types nat and int belong to this axclass;   830   831 * HOL: greatly improved simplification involving numerals of type nat, int, real:   832 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k   833 i*j + k + j*#3*i simplifies to #4*(i*j) + k   834 two terms #m*u and #n*u are replaced by #(m+n)*u   835 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)   836 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y   837 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);   838   839 * HOL: meson_tac is available (previously in ex/meson.ML); it is a   840 powerful prover for predicate logic but knows nothing of clasets; see   841 ex/mesontest.ML and ex/mesontest2.ML for example applications;   842   843 * HOL: new version of "case_tac" subsumes both boolean case split and   844 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer   845 exists, may define val exhaust_tac = case_tac for ad-hoc portability;   846   847 * HOL: simplification no longer dives into case-expressions: only the   848 selector expression is simplified, but not the remaining arms; to   849 enable full simplification of case-expressions for datatype t, you may   850 remove t.weak_case_cong from the simpset, either globally (Delcongs   851 [thm"t.weak_case_cong"];) or locally (delcongs [...]).   852   853 * HOL/recdef: the recursion equations generated by 'recdef' for   854 function 'f' are now called f.simps instead of f.rules; if all   855 termination conditions are proved automatically, these simplification   856 rules are added to the simpset, as in primrec; rules may be named   857 individually as well, resulting in a separate list of theorems for   858 each equation;   859   860 * HOL/While is a new theory that provides a while-combinator. It   861 permits the definition of tail-recursive functions without the   862 provision of a termination measure. The latter is necessary once the   863 invariant proof rule for while is applied.   864   865 * HOL: new (overloaded) notation for the set of elements below/above   866 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.   867   868 * HOL: theorems impI, allI, ballI bound as "strip";   869   870 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic   871 induct_tac th "x1 ... xn" expects th to have a conclusion of the form   872 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;   873   874 * HOL/Real: "rabs" replaced by overloaded "abs" function;   875   876 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of   877 main HOL, but was unused);   878   879 * HOL: fewer consts declared as global (e.g. have to refer to   880 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);   881   882 * HOL: tuned AST representation of nested pairs, avoiding bogus output   883 in case of overlap with user translations (e.g. judgements over   884 tuples); (note that the underlying logical represenation is still   885 bogus);   886   887   888 *** ZF ***   889   890 * ZF: simplification automatically cancels common terms in arithmetic   891 expressions over nat and int;   892   893 * ZF: new treatment of nat to minimize type-checking: all operators   894 coerce their operands to a natural number using the function natify,   895 making the algebraic laws unconditional;   896   897 * ZF: as above, for int: operators coerce their operands to an integer   898 using the function intify;   899   900 * ZF: the integer library now contains many of the usual laws for the   901 orderings, including$<=, and monotonicity laws for $+ and$*;

   902

   903 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic

   904 simplification;

   905

   906 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q

   907 to the simplifier and classical reasoner simultaneously;

   908

   909

   910 *** General ***

   911

   912 * Provers: blast_tac now handles actual object-logic rules as

   913 assumptions; note that auto_tac uses blast_tac internally as well;

   914

   915 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning

   916 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;

   917

   918 * Provers: delrules now handles destruct rules as well (no longer need

   919 explicit make_elim);

   920

   921 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.

   922   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

   923 use instead the strong form,

   924   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

   925 in HOL, FOL and ZF the function cla_make_elim will create such rules

   926 from destruct-rules;

   927

   928 * Provers: Simplifier.easy_setup provides a fast path to basic

   929 Simplifier setup for new object-logics;

   930

   931 * Pure: AST translation rules no longer require constant head on LHS;

   932

   933 * Pure: improved name spaces: ambiguous output is qualified; support

   934 for hiding of names;

   935

   936 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and

   937 XSYMBOL_HOME; no longer need to do manual configuration in most

   938 situations;

   939

   940 * system: compression of ML heaps images may now be controlled via -c

   941 option of isabelle and isatool usedir (currently only observed by

   942 Poly/ML);

   943

   944 * system: isatool installfonts may handle X-Symbol fonts as well (very

   945 useful for remote X11);

   946

   947 * system: provide TAGS file for Isabelle sources;

   948

   949 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument

   950 order;

   951

   952 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global

   953 timing flag supersedes proof_timing and Toplevel.trace;

   954

   955 * ML: new combinators |>> and |>>> for incremental transformations

   956 with secondary results (e.g. certain theory extensions):

   957

   958 * ML: PureThy.add_defs gets additional argument to indicate potential

   959 overloading (usually false);

   960

   961 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as

   962 results;

   963

   964

   965

   966 New in Isabelle99 (October 1999)

   967 --------------------------------

   968

   969 *** Overview of INCOMPATIBILITIES (see below for more details) ***

   970

   971 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)

   972 are no longer simplified.  (This allows the simplifier to unfold recursive

   973 functional programs.)  To restore the old behaviour, declare

   974

   975     Delcongs [if_weak_cong];

   976

   977 * HOL: Removed the obsolete syntax "Compl A"; use -A for set

   978 complement;

   979

   980 * HOL: the predicate "inj" is now defined by translation to "inj_on";

   981

   982 * HOL/datatype: mutual_induct_tac no longer exists --

   983   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]

   984

   985 * HOL/typedef: fixed type inference for representing set; type

   986 arguments now have to occur explicitly on the rhs as type constraints;

   987

   988 * ZF: The con_defs part of an inductive definition may no longer refer

   989 to constants declared in the same theory;

   990

   991 * HOL, ZF: the function mk_cases, generated by the inductive

   992 definition package, has lost an argument.  To simplify its result, it

   993 uses the default simpset instead of a supplied list of theorems.

   994

   995 * HOL/List: the constructors of type list are now Nil and Cons;

   996

   997 * Simplifier: the type of the infix ML functions

   998         setSSolver addSSolver setSolver addSolver

   999 is now  simpset * solver -> simpset  where solver' is a new abstract type

  1000 for packaging solvers. A solver is created via

  1001         mk_solver: string -> (thm list -> int -> tactic) -> solver

  1002 where the string argument is only a comment.

  1003

  1004

  1005 *** Proof tools ***

  1006

  1007 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a

  1008 decision procedure for linear arithmetic. Currently it is used for

  1009 types nat', int', and real' in HOL (see below); it can, should and

  1010 will be instantiated for other types and logics as well.

  1011

  1012 * The simplifier now accepts rewrite rules with flexible heads, eg

  1013      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y

  1014   They are applied like any rule with a non-pattern lhs, i.e. by first-order

  1015   matching.

  1016

  1017

  1018 *** General ***

  1019

  1020 * New Isabelle/Isar subsystem provides an alternative to traditional

  1021 tactical theorem proving; together with the ProofGeneral/isar user

  1022 interface it offers an interactive environment for developing human

  1023 readable proof documents (Isar == Intelligible semi-automated

  1024 reasoning); for further information see isatool doc isar-ref,

  1025 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/

  1026

  1027 * improved and simplified presentation of theories: better HTML markup

  1028 (including colors), graph views in several sizes; isatool usedir now

  1029 provides a proper interface for user theories (via -P option); actual

  1030 document preparation based on (PDF)LaTeX is available as well (for

  1031 new-style theories only); see isatool doc system for more information;

  1032

  1033 * native support for Proof General, both for classic Isabelle and

  1034 Isabelle/Isar;

  1035

  1036 * ML function thm_deps visualizes dependencies of theorems and lemmas,

  1037 using the graph browser tool;

  1038

  1039 * Isabelle manuals now also available as PDF;

  1040

  1041 * theory loader rewritten from scratch (may not be fully

  1042 bug-compatible); old loadpath variable has been replaced by show_path,

  1043 add_path, del_path, reset_path functions; new operations such as

  1044 update_thy, touch_thy, remove_thy, use/update_thy_only (see also

  1045 isatool doc ref);

  1046

  1047 * improved isatool install: option -k creates KDE application icon,

  1048 option -p DIR installs standalone binaries;

  1049

  1050 * added ML_PLATFORM setting (useful for cross-platform installations);

  1051 more robust handling of platform specific ML images for SML/NJ;

  1052

  1053 * the settings environment is now statically scoped, i.e. it is never

  1054 created again in sub-processes invoked from isabelle, isatool, or

  1055 Isabelle;

  1056

  1057 * path element specification '~~' refers to '$ISABELLE_HOME';   1058   1059 * in locales, the "assumes" and "defines" parts may be omitted if   1060 empty;   1061   1062 * new print_mode "xsymbols" for extended symbol support (e.g. genuine   1063 long arrows);   1064   1065 * new print_mode "HTML";   1066   1067 * new flag show_tags controls display of tags of theorems (which are   1068 basically just comments that may be attached by some tools);   1069   1070 * Isamode 2.6 requires patch to accomodate change of Isabelle font   1071 mode and goal output format:   1072   1073 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el   1074 244c244   1075 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)   1076 ---   1077 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)   1078 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el   1079 181c181   1080 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"

  1081 ---

  1082 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"

  1083

  1084 * function bind_thms stores lists of theorems (cf. bind_thm);

  1085

  1086 * new shorthand tactics ftac, eatac, datac, fatac;

  1087

  1088 * qed (and friends) now accept "" as result name; in that case the

  1089 theorem is not stored, but proper checks and presentation of the

  1090 result still apply;

  1091

  1092 * theorem database now also indexes constants "Trueprop", "all",

  1093 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;

  1094

  1095

  1096 *** HOL ***

  1097

  1098 ** HOL arithmetic **

  1099

  1100 * There are now decision procedures for linear arithmetic over nat and

  1101 int:

  1102

  1103 1. arith_tac copes with arbitrary formulae involving =', <', <=',

  1104 +', -', Suc', min', max' and numerical constants; other subterms

  1105 are treated as atomic; subformulae not involving type nat' or int'

  1106 are ignored; quantified subformulae are ignored unless they are

  1107 positive universal or negative existential. The tactic has to be

  1108 invoked by hand and can be a little bit slow. In particular, the

  1109 running time is exponential in the number of occurrences of min' and

  1110 max', and -' on nat'.

  1111

  1112 2. fast_arith_tac is a cut-down version of arith_tac: it only takes

  1113 (negated) (in)equalities among the premises and the conclusion into

  1114 account (i.e. no compound formulae) and does not know about min' and

  1115 max', and -' on nat'. It is fast and is used automatically by the

  1116 simplifier.

  1117

  1118 NB: At the moment, these decision procedures do not cope with mixed

  1119 nat/int formulae where the two parts interact, such as m < n ==>

  1120 int(m) < int(n)'.

  1121

  1122 * HOL/Numeral provides a generic theory of numerals (encoded

  1123 efficiently as bit strings); setup for types nat/int/real is in place;

  1124 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than

  1125 int, existing theories and proof scripts may require a few additional

  1126 type constraints;

  1127

  1128 * integer division and remainder can now be performed on constant

  1129 arguments;

  1130

  1131 * many properties of integer multiplication, division and remainder

  1132 are now available;

  1133

  1134 * An interface to the Stanford Validity Checker (SVC) is available through the

  1135 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic

  1136 are proved automatically.  SVC must be installed separately, and its results

  1137 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any

  1138 invocation of the underlying oracle).  For SVC see

  1139   http://verify.stanford.edu/SVC

  1140

  1141 * IsaMakefile: the HOL-Real target now builds an actual image;

  1142

  1143

  1144 ** HOL misc **

  1145

  1146 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces

  1147 (in Isabelle/Isar) -- by Gertrud Bauer;

  1148

  1149 * HOL/BCV: generic model of bytecode verification, i.e. data-flow

  1150 analysis for assembly languages with subtypes;

  1151

  1152 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization

  1153 -- avoids syntactic ambiguities and treats state, transition, and

  1154 temporal levels more uniformly; introduces INCOMPATIBILITIES due to

  1155 changed syntax and (many) tactics;

  1156

  1157 * HOL/inductive: Now also handles more general introduction rules such

  1158   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity

  1159   theorems are now maintained within the theory (maintained via the

  1160   "mono" attribute);

  1161

  1162 * HOL/datatype: Now also handles arbitrarily branching datatypes

  1163   (using function types) such as

  1164

  1165   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"

  1166

  1167 * HOL/record: record_simproc (part of the default simpset) takes care

  1168 of selectors applied to updated records; record_split_tac is no longer

  1169 part of the default claset; update_defs may now be removed from the

  1170 simpset in many cases; COMPATIBILITY: old behavior achieved by

  1171

  1172   claset_ref () := claset() addSWrapper record_split_wrapper;

  1173   Delsimprocs [record_simproc]

  1174

  1175 * HOL/typedef: fixed type inference for representing set; type

  1176 arguments now have to occur explicitly on the rhs as type constraints;

  1177

  1178 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem

  1179 names rather than an ML expression;

  1180

  1181 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be

  1182 supplied later.  Program schemes can be defined, such as

  1183     "While B C s = (if B s then While B C (C s) else s)"

  1184 where the well-founded relation can be chosen after B and C have been given.

  1185

  1186 * HOL/List: the constructors of type list are now Nil and Cons;

  1187 INCOMPATIBILITY: while [] and infix # syntax is still there, of

  1188 course, ML tools referring to List.list.op # etc. have to be adapted;

  1189

  1190 * HOL_quantifiers flag superseded by "HOL" print mode, which is

  1191 disabled by default; run isabelle with option -m HOL to get back to

  1192 the original Gordon/HOL-style output;

  1193

  1194 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,

  1195 ALL x<=y. P, EX x<y. P, EX x<=y. P;

  1196

  1197 * HOL basic syntax simplified (more orthogonal): all variants of

  1198 All/Ex now support plain / symbolic / HOL notation; plain syntax for

  1199 Eps operator is provided as well: "SOME x. P[x]";

  1200

  1201 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;

  1202

  1203 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made

  1204 thus available for user theories;

  1205

  1206 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with

  1207 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the

  1208 time;

  1209

  1210 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec

  1211 several times and then mp;

  1212

  1213

  1214 *** LK ***

  1215

  1216 * the notation <<...>> is now available as a notation for sequences of

  1217 formulas;

  1218

  1219 * the simplifier is now installed

  1220

  1221 * the axiom system has been generalized (thanks to Soren Heilmann)

  1222

  1223 * the classical reasoner now has a default rule database

  1224

  1225

  1226 *** ZF ***

  1227

  1228 * new primrec section allows primitive recursive functions to be given

  1229 directly (as in HOL) over datatypes and the natural numbers;

  1230

  1231 * new tactics induct_tac and exhaust_tac for induction (or case

  1232 analysis) over datatypes and the natural numbers;

  1233

  1234 * the datatype declaration of type T now defines the recursor T_rec;

  1235

  1236 * simplification automatically does freeness reasoning for datatype

  1237 constructors;

  1238

  1239 * automatic type-inference, with AddTCs command to insert new

  1240 type-checking rules;

  1241

  1242 * datatype introduction rules are now added as Safe Introduction rules

  1243 to the claset;

  1244

  1245 * the syntax "if P then x else y" is now available in addition to

  1246 if(P,x,y);

  1247

  1248

  1249 *** Internal programming interfaces ***

  1250

  1251 * tuned simplifier trace output; new flag debug_simp;

  1252

  1253 * structures Vartab / Termtab (instances of TableFun) offer efficient

  1254 tables indexed by indexname_ord / term_ord (compatible with aconv);

  1255

  1256 * AxClass.axclass_tac lost the theory argument;

  1257

  1258 * tuned current_goals_markers semantics: begin / end goal avoids

  1259 printing empty lines;

  1260

  1261 * removed prs and prs_fn hook, which was broken because it did not

  1262 include \n in its semantics, forcing writeln to add one

  1263 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

  1264 string -> unit if you really want to output text without newline;

  1265

  1266 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to

  1267 plain output, interface builders may have to enable 'isabelle_font'

  1268 mode to get Isabelle font glyphs as before;

  1269

  1270 * refined token_translation interface; INCOMPATIBILITY: output length

  1271 now of type real instead of int;

  1272

  1273 * theory loader actions may be traced via new ThyInfo.add_hook

  1274 interface (see src/Pure/Thy/thy_info.ML); example application: keep

  1275 your own database of information attached to *whole* theories -- as

  1276 opposed to intra-theory data slots offered via TheoryDataFun;

  1277

  1278 * proper handling of dangling sort hypotheses (at last!);

  1279 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing

  1280 extra sort hypotheses that can be witnessed from the type signature;

  1281 the force_strip_shyps flag is gone, any remaining shyps are simply

  1282 left in the theorem (with a warning issued by strip_shyps_warning);

  1283

  1284

  1285

  1286 New in Isabelle98-1 (October 1998)

  1287 ----------------------------------

  1288

  1289 *** Overview of INCOMPATIBILITIES (see below for more details) ***

  1290

  1291 * several changes of automated proof tools;

  1292

  1293 * HOL: major changes to the inductive and datatype packages, including

  1294 some minor incompatibilities of theory syntax;

  1295

  1296 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now

  1297 called inj_on';

  1298

  1299 * HOL: removed duplicate thms in Arith:

  1300   less_imp_add_less  should be replaced by  trans_less_add1

  1301   le_imp_add_le      should be replaced by  trans_le_add1

  1302

  1303 * HOL: unary minus is now overloaded (new type constraints may be

  1304 required);

  1305

  1306 * HOL and ZF: unary minus for integers is now #- instead of #~.  In

  1307 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is

  1308 now taken as an integer constant.

  1309

  1310 * Pure: ML function 'theory_of' renamed to 'theory';

  1311

  1312

  1313 *** Proof tools ***

  1314

  1315 * Simplifier:

  1316   1. Asm_full_simp_tac is now more aggressive.

  1317      1. It will sometimes reorient premises if that increases their power to

  1318         simplify.

  1319      2. It does no longer proceed strictly from left to right but may also

  1320         rotate premises to achieve further simplification.

  1321      For compatibility reasons there is now Asm_lr_simp_tac which is like the

  1322      old Asm_full_simp_tac in that it does not rotate premises.

  1323   2. The simplifier now knows a little bit about nat-arithmetic.

  1324

  1325 * Classical reasoner: wrapper mechanism for the classical reasoner now

  1326 allows for selected deletion of wrappers, by introduction of names for

  1327 wrapper functionals.  This implies that addbefore, addSbefore,

  1328 addaltern, and addSaltern now take a pair (name, tactic) as argument,

  1329 and that adding two tactics with the same name overwrites the first

  1330 one (emitting a warning).

  1331   type wrapper = (int -> tactic) -> (int -> tactic)

  1332   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

  1333   addWrapper, addSWrapper: claset * (string * wrapper) -> claset

  1334   delWrapper, delSWrapper: claset *  string            -> claset

  1335   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

  1336

  1337 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE

  1338 semantics; addbefore now affects only the unsafe part of step_tac

  1339 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY

  1340 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac

  1341 by Force_tac;

  1342

  1343 * Classical reasoner: setwrapper to setWrapper and compwrapper to

  1344 compWrapper; added safe wrapper (and access functions for it);

  1345

  1346 * HOL/split_all_tac is now much faster and fails if there is nothing

  1347 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order

  1348 and the names of the automatically generated variables have changed.

  1349 split_all_tac has moved within claset() from unsafe wrappers to safe

  1350 wrappers, which means that !!-bound variables are split much more

  1351 aggressively, and safe_tac and clarify_tac now split such variables.

  1352 If this splitting is not appropriate, use delSWrapper "split_all_tac".

  1353 Note: the same holds for record_split_tac, which does the job of

  1354 split_all_tac for record fields.

  1355

  1356 * HOL/Simplifier: Rewrite rules for case distinctions can now be added

  1357 permanently to the default simpset using Addsplits just like

  1358 Addsimps. They can be removed via Delsplits just like

  1359 Delsimps. Lower-case versions are also available.

  1360

  1361 * HOL/Simplifier: The rule split_if is now part of the default

  1362 simpset. This means that the simplifier will eliminate all occurrences

  1363 of if-then-else in the conclusion of a goal. To prevent this, you can

  1364 either remove split_if completely from the default simpset by

  1365 Delsplits [split_if]' or remove it in a specific call of the

  1366 simplifier using ... delsplits [split_if]'.  You can also add/delete

  1367 other case splitting rules to/from the default simpset: every datatype

  1368 generates suitable rules split_t_case' and split_t_case_asm' (where

  1369 t is the name of the datatype).

  1370

  1371 * Classical reasoner / Simplifier combination: new force_tac (and

  1372 derivatives Force_tac, force) combines rewriting and classical

  1373 reasoning (and whatever other tools) similarly to auto_tac, but is

  1374 aimed to solve the given subgoal completely.

  1375

  1376

  1377 *** General ***

  1378

  1379 * new top-level commands Goal' and Goalw' that improve upon goal'

  1380 and goalw': the theory is no longer needed as an explicit argument -

  1381 the current theory context is used; assumptions are no longer returned

  1382 at the ML-level unless one of them starts with ==> or !!; it is

  1383 recommended to convert to these new commands using isatool fixgoal

  1384 (backup your sources first!);

  1385

  1386 * new top-level commands 'thm' and 'thms' for retrieving theorems from

  1387 the current theory context, and 'theory' to lookup stored theories;

  1388

  1389 * new theory section 'locale' for declaring constants, assumptions and

  1390 definitions that have local scope;

  1391

  1392 * new theory section 'nonterminals' for purely syntactic types;

  1393

  1394 * new theory section 'setup' for generic ML setup functions

  1395 (e.g. package initialization);

  1396

  1397 * the distribution now includes Isabelle icons: see

  1398 lib/logo/isabelle-{small,tiny}.xpm;

  1399

  1400 * isatool install - install binaries with absolute references to

  1401 ISABELLE_HOME/bin;

  1402

  1403 * isatool logo -- create instances of the Isabelle logo (as EPS);

  1404

  1405 * print mode 'emacs' reserved for Isamode;

  1406

  1407 * support multiple print (ast) translations per constant name;

  1408

  1409 * theorems involving oracles are now printed with a suffixed [!];

  1410

  1411

  1412 *** HOL ***

  1413

  1414 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');

  1415

  1416 * HOL/inductive package reorganized and improved: now supports mutual

  1417 definitions such as

  1418

  1419   inductive EVEN ODD

  1420     intrs

  1421       null "0 : EVEN"

  1422       oddI "n : EVEN ==> Suc n : ODD"

  1423       evenI "n : ODD ==> Suc n : EVEN"

  1424

  1425 new theorem list "elims" contains an elimination rule for each of the

  1426 recursive sets; inductive definitions now handle disjunctive premises

  1427 correctly (also ZF);

  1428

  1429 INCOMPATIBILITIES: requires Inductive as an ancestor; component

  1430 "mutual_induct" no longer exists - the induction rule is always

  1431 contained in "induct";

  1432

  1433

  1434 * HOL/datatype package re-implemented and greatly improved: now

  1435 supports mutually recursive datatypes such as

  1436

  1437   datatype

  1438     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)

  1439             | SUM ('a aexp) ('a aexp)

  1440             | DIFF ('a aexp) ('a aexp)

  1441             | NUM 'a

  1442   and

  1443     'a bexp = LESS ('a aexp) ('a aexp)

  1444             | AND ('a bexp) ('a bexp)

  1445             | OR ('a bexp) ('a bexp)

  1446

  1447 as well as indirectly recursive datatypes such as

  1448

  1449   datatype

  1450     ('a, 'b) term = Var 'a

  1451                   | App 'b ((('a, 'b) term) list)

  1452

  1453 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs

  1454 induction on mutually / indirectly recursive datatypes.

  1455

  1456 Primrec equations are now stored in theory and can be accessed via

  1457 <function_name>.simps.

  1458

  1459 INCOMPATIBILITIES:

  1460

  1461   - Theories using datatypes must now have theory Datatype as an

  1462     ancestor.

  1463   - The specific <typename>.induct_tac no longer exists - use the

  1464     generic induct_tac instead.

  1465   - natE has been renamed to nat.exhaust - use exhaust_tac

  1466     instead of res_inst_tac ... natE. Note that the variable

  1467     names in nat.exhaust differ from the names in natE, this

  1468     may cause some "fragile" proofs to fail.

  1469   - The theorems split_<typename>_case and split_<typename>_case_asm

  1470     have been renamed to <typename>.split and <typename>.split_asm.

  1471   - Since default sorts of type variables are now handled correctly,

  1472     some datatype definitions may have to be annotated with explicit

  1473     sort constraints.

  1474   - Primrec definitions no longer require function name and type

  1475     of recursive argument.

  1476

  1477 Consider using isatool fixdatatype to adapt your theories and proof

  1478 scripts to the new package (backup your sources first!).

  1479

  1480

  1481 * HOL/record package: considerably improved implementation; now

  1482 includes concrete syntax for record types, terms, updates; theorems

  1483 for surjective pairing and splitting !!-bound record variables; proof

  1484 support is as follows:

  1485

  1486   1) standard conversions (selectors or updates applied to record

  1487 constructor terms) are part of the standard simpset;

  1488

  1489   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are

  1490 made part of standard simpset and claset via addIffs;

  1491

  1492   3) a tactic for record field splitting (record_split_tac) is part of

  1493 the standard claset (addSWrapper);

  1494

  1495 To get a better idea about these rules you may retrieve them via

  1496 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is

  1497 the name of your record type.

  1498

  1499 The split tactic 3) conceptually simplifies by the following rule:

  1500

  1501   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"

  1502

  1503 Thus any record variable that is bound by meta-all will automatically

  1504 blow up into some record constructor term, consequently the

  1505 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall

  1506 solve record problems automatically.

  1507

  1508

  1509 * reorganized the main HOL image: HOL/Integ and String loaded by

  1510 default; theory Main includes everything;

  1511

  1512 * automatic simplification of integer sums and comparisons, using cancellation;

  1513

  1514 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;

  1515

  1516 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;

  1517

  1518 * many new identities for unions, intersections, set difference, etc.;

  1519

  1520 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

  1521 called split_if, split_split, split_sum_case and split_nat_case (to go

  1522 with add/delsplits);

  1523

  1524 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

  1525 (?x::unit) = (); this is made part of the default simpset, which COULD

  1526 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

  1527 'Delsimprocs [unit_eq_proc];' as last resort); also note that

  1528 unit_abs_eta_conv is added in order to counter the effect of

  1529 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by

  1530 %u.f();

  1531

  1532 * HOL/Fun INCOMPATIBILITY: inj_onto' is now called inj_on' (which

  1533 makes more sense);

  1534

  1535 * HOL/Set INCOMPATIBILITY: rule equals0D' is now a well-formed destruct rule;

  1536   It and 'sym RS equals0D' are now in the default  claset, giving automatic

  1537   disjointness reasoning but breaking a few old proofs.

  1538

  1539 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1

  1540 to 'converse' from 'inverse' (for compatibility with ZF and some

  1541 literature);

  1542

  1543 * HOL/recdef can now declare non-recursive functions, with {} supplied as

  1544 the well-founded relation;

  1545

  1546 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of

  1547     Compl A.  The "Compl" syntax remains available as input syntax for this

  1548     release ONLY.

  1549

  1550 * HOL/Update: new theory of function updates:

  1551     f(a:=b) == %x. if x=a then b else f x

  1552 may also be iterated as in f(a:=b,c:=d,...);

  1553

  1554 * HOL/Vimage: new theory for inverse image of a function, syntax f-B;

  1555

  1556 * HOL/List:

  1557   - new function list_update written xs[i:=v] that updates the i-th

  1558     list position. May also be iterated as in xs[i:=a,j:=b,...].

  1559   - new function upt' written [i..j(] which generates the list

  1560     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper

  1561     bound write [i..j], which is a shorthand for [i..j+1(].

  1562   - new lexicographic orderings and corresponding wellfoundedness theorems.

  1563

  1564 * HOL/Arith:

  1565   - removed 'pred' (predecessor) function;

  1566   - generalized some theorems about n-1;

  1567   - many new laws about "div" and "mod";

  1568   - new laws about greatest common divisors (see theory ex/Primes);

  1569

  1570 * HOL/Relation: renamed the relational operator r^-1 "converse"

  1571 instead of "inverse";

  1572

  1573 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness

  1574   of the multiset ordering;

  1575

  1576 * directory HOL/Real: a construction of the reals using Dedekind cuts

  1577   (not included by default);

  1578

  1579 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;

  1580

  1581 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted

  1582   programs, i.e. different program variables may have different types.

  1583

  1584 * calling (stac rew i) now fails if "rew" has no effect on the goal

  1585   [previously, this check worked only if the rewrite rule was unconditional]

  1586   Now rew can involve either definitions or equalities (either == or =).

  1587

  1588

  1589 *** ZF ***

  1590

  1591 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains

  1592   only the theorems proved on ZF.ML;

  1593

  1594 * ZF INCOMPATIBILITY: rule equals0D' is now a well-formed destruct rule;

  1595   It and 'sym RS equals0D' are now in the default  claset, giving automatic

  1596   disjointness reasoning but breaking a few old proofs.

  1597

  1598 * ZF/Update: new theory of function updates

  1599     with default rewrite rule  f(x:=y)  z = if(z=x, y, fz)

  1600   may also be iterated as in f(a:=b,c:=d,...);

  1601

  1602 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.

  1603

  1604 * calling (stac rew i) now fails if "rew" has no effect on the goal

  1605   [previously, this check worked only if the rewrite rule was unconditional]

  1606   Now rew can involve either definitions or equalities (either == or =).

  1607

  1608 * case_tac provided for compatibility with HOL

  1609     (like the old excluded_middle_tac, but with subgoals swapped)

  1610

  1611

  1612 *** Internal programming interfaces ***

  1613

  1614 * Pure: several new basic modules made available for general use, see

  1615 also src/Pure/README;

  1616

  1617 * improved the theory data mechanism to support encapsulation (data

  1618 kind name replaced by private Object.kind, acting as authorization

  1619 key); new type-safe user interface via functor TheoryDataFun; generic

  1620 print_data function becomes basically useless;

  1621

  1622 * removed global_names compatibility flag -- all theory declarations

  1623 are qualified by default;

  1624

  1625 * module Pure/Syntax now offers quote / antiquote translation

  1626 functions (useful for Hoare logic etc. with implicit dependencies);

  1627 see HOL/ex/Antiquote for an example use;

  1628

  1629 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->

  1630 cterm -> thm;

  1631

  1632 * new tactical CHANGED_GOAL for checking that a tactic modifies a

  1633 subgoal;

  1634

  1635 * Display.print_goals function moved to Locale.print_goals;

  1636

  1637 * standard print function for goals supports current_goals_markers

  1638 variable for marking begin of proof, end of proof, start of goal; the

  1639 default is ("", "", ""); setting current_goals_markers := ("<proof>",

  1640 "</proof>", "<goal>") causes SGML like tagged proof state printing,

  1641 for example;

  1642

  1643

  1644

  1645 New in Isabelle98 (January 1998)

  1646 --------------------------------

  1647

  1648 *** Overview of INCOMPATIBILITIES (see below for more details) ***

  1649

  1650 * changed lexical syntax of terms / types: dots made part of long

  1651 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";

  1652

  1653 * simpset (and claset) reference variable replaced by functions

  1654 simpset / simpset_ref;

  1655

  1656 * no longer supports theory aliases (via merge) and non-trivial

  1657 implicit merge of thms' signatures;

  1658

  1659 * most internal names of constants changed due to qualified names;

  1660

  1661 * changed Pure/Sequence interface (see Pure/seq.ML);

  1662

  1663

  1664 *** General Changes ***

  1665

  1666 * hierachically structured name spaces (for consts, types, axms, thms

  1667 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of

  1668 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:

  1669 isatool fixdots ensures space after dots (e.g. "%x. x"); set

  1670 long_names for fully qualified output names; NOTE: ML programs

  1671 (special tactics, packages etc.) referring to internal names may have

  1672 to be adapted to cope with fully qualified names; in case of severe

  1673 backward campatibility problems try setting 'global_names' at compile

  1674 time to have enrything declared within a flat name space; one may also

  1675 fine tune name declarations in theories via the 'global' and 'local'

  1676 section;

  1677

  1678 * reimplemented the implicit simpset and claset using the new anytype

  1679 data filed in signatures; references simpset:simpset ref etc. are

  1680 replaced by functions simpset:unit->simpset and

  1681 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp

  1682 to patch your ML files accordingly;

  1683

  1684 * HTML output now includes theory graph data for display with Java

  1685 applet or isatool browser; data generated automatically via isatool

  1686 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

  1687

  1688 * defs may now be conditional; improved rewrite_goals_tac to handle

  1689 conditional equations;

  1690

  1691 * defs now admits additional type arguments, using TYPE('a) syntax;

  1692

  1693 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always

  1694 creates a new theory node; implicit merge of thms' signatures is

  1695 restricted to 'trivial' ones; COMPATIBILITY: one may have to use

  1696 transfer:theory->thm->thm in (rare) cases;

  1697

  1698 * improved handling of draft signatures / theories; draft thms (and

  1699 ctyps, cterms) are automatically promoted to real ones;

  1700

  1701 * slightly changed interfaces for oracles: admit many per theory, named

  1702 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;

  1703

  1704 * print_goals: optional output of const types (set show_consts and

  1705 show_types);

  1706

  1707 * improved output of warnings (###) and errors (***);

  1708

  1709 * subgoal_tac displays a warning if the new subgoal has type variables;

  1710

  1711 * removed old README and Makefiles;

  1712

  1713 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

  1714

  1715 * removed obsolete init_pps and init_database;

  1716

  1717 * deleted the obsolete tactical STATE, which was declared by

  1718     fun STATE tacfun st = tacfun st st;

  1719

  1720 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~   1721 (which abbreviates$HOME);

  1722

  1723 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:

  1724 use isatool fixseq to adapt your ML programs (this works for fully

  1725 qualified references to the Sequence structure only!);

  1726

  1727 * use_thy no longer requires writable current directory; it always

  1728 reloads .ML *and* .thy file, if either one is out of date;

  1729

  1730

  1731 *** Classical Reasoner ***

  1732

  1733 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

  1734 tactics that use classical reasoning to simplify a subgoal without

  1735 splitting it into several subgoals;

  1736

  1737 * Safe_tac: like safe_tac but uses the default claset;

  1738

  1739

  1740 *** Simplifier ***

  1741

  1742 * added simplification meta rules:

  1743     (asm_)(full_)simplify: simpset -> thm -> thm;

  1744

  1745 * simplifier.ML no longer part of Pure -- has to be loaded by object

  1746 logics (again);

  1747

  1748 * added prems argument to simplification procedures;

  1749

  1750 * HOL, FOL, ZF: added infix function addsplits':

  1751   instead of <simpset> setloop (split_tac <thms>)'

  1752   you can simply write <simpset> addsplits <thms>'

  1753

  1754

  1755 *** Syntax ***

  1756

  1757 * TYPE('a) syntax for type reflection terms;

  1758

  1759 * no longer handles consts with name "" -- declare as 'syntax' instead;

  1760

  1761 * pretty printer: changed order of mixfix annotation preference (again!);

  1762

  1763 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;

  1764

  1765

  1766 *** HOL ***

  1767

  1768 * HOL: there is a new splitter split_asm_tac' that can be used e.g.

  1769   with addloop' of the simplifier to faciliate case splitting in premises.

  1770

  1771 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;

  1772

  1773 * HOL/Auth: new protocol proofs including some for the Internet

  1774   protocol TLS;

  1775

  1776 * HOL/Map: new theory of maps' a la VDM;

  1777

  1778 * HOL/simplifier: simplification procedures nat_cancel_sums for

  1779 cancelling out common nat summands from =, <, <= (in)equalities, or

  1780 differences; simplification procedures nat_cancel_factor for

  1781 cancelling common factor from =, <, <= (in)equalities over natural

  1782 sums; nat_cancel contains both kinds of procedures, it is installed by

  1783 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;

  1784

  1785 * HOL/simplifier: terms of the form

  1786   ? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)

  1787   are rewritten to

  1788   P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',

  1789   and those of the form

  1790   ! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)

  1791   are rewritten to

  1792   P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',

  1793

  1794 * HOL/datatype

  1795   Each datatype t' now comes with a theorem split_t_case' of the form

  1796

  1797   P(t_case f1 ... fn x) =

  1798      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &

  1799         ...

  1800        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))

  1801      )

  1802

  1803   and a theorem split_t_case_asm' of the form

  1804

  1805   P(t_case f1 ... fn x) =

  1806     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |

  1807         ...

  1808        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))

  1809      )

  1810   which can be added to a simpset via addsplits'. The existing theorems

  1811   expand_list_case and expand_option_case have been renamed to

  1812   split_list_case and split_option_case.

  1813

  1814 * HOL/Arithmetic:

  1815   - pred n' is automatically converted to n-1'.

  1816     Users are strongly encouraged not to use pred' any longer,

  1817     because it will disappear altogether at some point.

  1818   - Users are strongly encouraged to write "0 < n" rather than

  1819     "n ~= 0". Theorems and proof tools have been modified towards this

  1820     standard'.

  1821

  1822 * HOL/Lists:

  1823   the function "set_of_list" has been renamed "set" (and its theorems too);

  1824   the function "nth" now takes its arguments in the reverse order and

  1825   has acquired the infix notation "!" as in "xs!n".

  1826

  1827 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};

  1828

  1829 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its

  1830   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);

  1831

  1832 * HOL/record: extensible records with schematic structural subtyping

  1833 (single inheritance); EXPERIMENTAL version demonstrating the encoding,

  1834 still lacks various theorems and concrete record syntax;

  1835

  1836

  1837 *** HOLCF ***

  1838

  1839 * removed "axioms" and "generated by" sections;

  1840

  1841 * replaced "ops" section by extended "consts" section, which is capable of

  1842   handling the continuous function space "->" directly;

  1843

  1844 * domain package:

  1845   . proves theorems immediately and stores them in the theory,

  1846   . creates hierachical name space,

  1847   . now uses normal mixfix annotations (instead of cinfix...),

  1848   . minor changes to some names and values (for consistency),

  1849   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,

  1850   . separator between mutual domain defs: changed "," to "and",

  1851   . improved handling of sort constraints;  now they have to

  1852     appear on the left-hand side of the equations only;

  1853

  1854 * fixed LAM <x,y,zs>.b syntax;

  1855

  1856 * added extended adm_tac to simplifier in HOLCF -- can now discharge

  1857 adm (%x. P (t x)), where P is chainfinite and t continuous;

  1858

  1859

  1860 *** FOL and ZF ***

  1861

  1862 * FOL: there is a new splitter split_asm_tac' that can be used e.g.

  1863   with addloop' of the simplifier to faciliate case splitting in premises.

  1864

  1865 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

  1866 in HOL, they strip ALL and --> from proved theorems;

  1867

  1868

  1869

  1870 New in Isabelle94-8 (May 1997)

  1871 ------------------------------

  1872

  1873 *** General Changes ***

  1874

  1875 * new utilities to build / run / maintain Isabelle etc. (in parts

  1876 still somewhat experimental); old Makefiles etc. still functional;

  1877

  1878 * new 'Isabelle System Manual';

  1879

  1880 * INSTALL text, together with ./configure and ./build scripts;

  1881

  1882 * reimplemented type inference for greater efficiency, better error

  1883 messages and clean internal interface;

  1884

  1885 * prlim command for dealing with lots of subgoals (an easier way of

  1886 setting goals_limit);

  1887

  1888

  1889 *** Syntax ***

  1890

  1891 * supports alternative (named) syntax tables (parser and pretty

  1892 printer); internal interface is provided by add_modesyntax(_i);

  1893

  1894 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

  1895 be used in conjunction with the Isabelle symbol font; uses the

  1896 "symbols" syntax table;

  1897

  1898 * added token_translation interface (may translate name tokens in

  1899 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

  1900 the current print_mode); IMPORTANT: user print translation functions

  1901 are responsible for marking newly introduced bounds

  1902 (Syntax.mark_boundT);

  1903

  1904 * token translations for modes "xterm" and "xterm_color" that display

  1905 names in bold, underline etc. or colors (which requires a color

  1906 version of xterm);

  1907

  1908 * infixes may now be declared with names independent of their syntax;

  1909

  1910 * added typed_print_translation (like print_translation, but may

  1911 access type of constant);

  1912

  1913

  1914 *** Classical Reasoner ***

  1915

  1916 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has

  1917 some limitations.  Blast_tac...

  1918   + ignores addss, addbefore, addafter; this restriction is intrinsic

  1919   + ignores elimination rules that don't have the correct format

  1920         (the conclusion MUST be a formula variable)

  1921   + ignores types, which can make HOL proofs fail

  1922   + rules must not require higher-order unification, e.g. apply_type in ZF

  1923     [message "Function Var's argument not a bound variable" relates to this]

  1924   + its proof strategy is more general but can actually be slower

  1925

  1926 * substitution with equality assumptions no longer permutes other

  1927 assumptions;

  1928

  1929 * minor changes in semantics of addafter (now called addaltern); renamed

  1930 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

  1931 (and access functions for it);

  1932

  1933 * improved combination of classical reasoner and simplifier:

  1934   + functions for handling clasimpsets

  1935   + improvement of addss: now the simplifier is called _after_ the

  1936     safe steps.

  1937   + safe variant of addss called addSss: uses safe simplifications

  1938     _during_ the safe steps. It is more complete as it allows multiple

  1939     instantiations of unknowns (e.g. with slow_tac).

  1940

  1941 *** Simplifier ***

  1942

  1943 * added interface for simplification procedures (functions that

  1944 produce *proven* rewrite rules on the fly, depending on current

  1945 redex);

  1946

  1947 * ordering on terms as parameter (used for ordered rewriting);

  1948

  1949 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

  1950

  1951 * the solver is now split into a safe and an unsafe part.

  1952 This should be invisible for the normal user, except that the

  1953 functions setsolver and addsolver have been renamed to setSolver and

  1954 addSolver; added safe_asm_full_simp_tac;

  1955

  1956

  1957 *** HOL ***

  1958

  1959 * a generic induction tactic induct_tac' which works for all datatypes and

  1960 also for type nat';

  1961

  1962 * a generic case distinction tactic exhaust_tac' which works for all

  1963 datatypes and also for type nat';

  1964

  1965 * each datatype comes with a function size';

  1966

  1967 * patterns in case expressions allow tuple patterns as arguments to

  1968 constructors, for example case x of [] => ... | (x,y,z)#ps => ...';

  1969

  1970 * primrec now also works with type nat;

  1971

  1972 * recdef: a new declaration form, allows general recursive functions to be

  1973 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

  1974

  1975 * the constant for negation has been renamed from "not" to "Not" to

  1976 harmonize with FOL, ZF, LK, etc.;

  1977

  1978 * HOL/ex/LFilter theory of a corecursive "filter" functional for

  1979 infinite lists;

  1980

  1981 * HOL/Modelcheck demonstrates invocation of model checker oracle;

  1982

  1983 * HOL/ex/Ring.thy declares cring_simp, which solves equational

  1984 problems in commutative rings, using axiomatic type classes for + and *;

  1985

  1986 * more examples in HOL/MiniML and HOL/Auth;

  1987

  1988 * more default rewrite rules for quantifiers, union/intersection;

  1989

  1990 * a new constant arbitrary == @x.False';

  1991

  1992 * HOLCF/IOA replaces old HOL/IOA;

  1993

  1994 * HOLCF changes: derived all rules and arities

  1995   + axiomatic type classes instead of classes

  1996   + typedef instead of faking type definitions

  1997   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

  1998   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

  1999   + eliminated the types void, one, tr

  2000   + use unit lift and bool lift (with translations) instead of one and tr

  2001   + eliminated blift from Lift3.thy (use Def instead of blift)

  2002   all eliminated rules are derived as theorems --> no visible changes ;

  2003

  2004

  2005 *** ZF ***

  2006

  2007 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default

  2008 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back

  2009 as ZF_cs addSIs [equalityI];

  2010

  2011

  2012

  2013 New in Isabelle94-7 (November 96)

  2014 ---------------------------------

  2015

  2016 * allowing negative levels (as offsets) in prlev and choplev;

  2017

  2018 * super-linear speedup for large simplifications;

  2019

  2020 * FOL, ZF and HOL now use miniscoping: rewriting pushes

  2021 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

  2022 FAIL); can suppress it using the command Delsimps (ex_simps @

  2023 all_simps); De Morgan laws are also now included, by default;

  2024

  2025 * improved printing of ==>  :  ~:

  2026

  2027 * new object-logic "Sequents" adds linear logic, while replacing LK

  2028 and Modal (thanks to Sara Kalvala);

  2029

  2030 * HOL/Auth: correctness proofs for authentication protocols;

  2031

  2032 * HOL: new auto_tac combines rewriting and classical reasoning (many

  2033 examples on HOL/Auth);

  2034

  2035 * HOL: new command AddIffs for declaring theorems of the form P=Q to

  2036 the rewriter and classical reasoner simultaneously;

  2037

  2038 * function uresult no longer returns theorems in "standard" format;

  2039 regain previous version by: val uresult = standard o uresult;

  2040

  2041

  2042

  2043 New in Isabelle94-6

  2044 -------------------

  2045

  2046 * oracles -- these establish an interface between Isabelle and trusted

  2047 external reasoners, which may deliver results as theorems;

  2048

  2049 * proof objects (in particular record all uses of oracles);

  2050

  2051 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

  2052

  2053 * "constdefs" section in theory files;

  2054

  2055 * "primrec" section (HOL) no longer requires names;

  2056

  2057 * internal type "tactic" now simply "thm -> thm Sequence.seq";

  2058

  2059

  2060

  2061 New in Isabelle94-5

  2062 -------------------

  2063

  2064 * reduced space requirements;

  2065

  2066 * automatic HTML generation from theories;

  2067

  2068 * theory files no longer require "..." (quotes) around most types;

  2069

  2070 * new examples, including two proofs of the Church-Rosser theorem;

  2071

  2072 * non-curried (1994) version of HOL is no longer distributed;

  2073

  2074

  2075

  2076 New in Isabelle94-4

  2077 -------------------

  2078

  2079 * greatly reduced space requirements;

  2080

  2081 * theory files (.thy) no longer require \...\ escapes at line breaks;

  2082

  2083 * searchable theorem database (see the section "Retrieving theorems" on

  2084 page 8 of the Reference Manual);

  2085

  2086 * new examples, including Grabczewski's monumental case study of the

  2087 Axiom of Choice;

  2088

  2089 * The previous version of HOL renamed to Old_HOL;

  2090

  2091 * The new version of HOL (previously called CHOL) uses a curried syntax

  2092 for functions.  Application looks like f a b instead of f(a,b);

  2093

  2094 * Mutually recursive inductive definitions finally work in HOL;

  2095

  2096 * In ZF, pattern-matching on tuples is now available in all abstractions and

  2097 translates to the operator "split";

  2098

  2099

  2100

  2101 New in Isabelle94-3

  2102 -------------------

  2103

  2104 * new infix operator, addss, allowing the classical reasoner to

  2105 perform simplification at each step of its search.  Example:

  2106         fast_tac (cs addss ss)

  2107

  2108 * a new logic, CHOL, the same as HOL, but with a curried syntax

  2109 for functions.  Application looks like f a b instead of f(a,b).  Also pairs

  2110 look like (a,b) instead of <a,b>;

  2111

  2112 * PLEASE NOTE: CHOL will eventually replace HOL!

  2113

  2114 * In CHOL, pattern-matching on tuples is now available in all abstractions.

  2115 It translates to the operator "split".  A new theory of integers is available;

  2116

  2117 * In ZF, integer numerals now denote two's-complement binary integers.

  2118 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;

  2119

  2120 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

  2121 of the Axiom of Choice;

  2122

  2123

  2124

  2125 New in Isabelle94-2

  2126 -------------------

  2127

  2128 * Significantly faster resolution;

  2129

  2130 * the different sections in a .thy file can now be mixed and repeated

  2131 freely;

  2132

  2133 * Database of theorems for FOL, HOL and ZF.  New

  2134 commands including qed, qed_goal and bind_thm store theorems in the database.

  2135

  2136 * Simple database queries: return a named theorem (get_thm) or all theorems of

  2137 a given theory (thms_of), or find out what theory a theorem was proved in

  2138 (theory_of_thm);

  2139

  2140 * Bugs fixed in the inductive definition and datatype packages;

  2141

  2142 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

  2143 and HOL_dup_cs obsolete;

  2144

  2145 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

  2146 have been removed;

  2147

  2148 * Simpler definition of function space in ZF;

  2149

  2150 * new results about cardinal and ordinal arithmetic in ZF;

  2151

  2152 * 'subtype' facility in HOL for introducing new types as subsets of existing

  2153 types;

  2154

  2155

  2156 $Id$