1 Isabelle NEWS -- history user-relevant changes
2 ==============================================
4 New in this Isabelle release
5 ----------------------------
9 * Pure: locale specifications now produce predicate definitions
10 according to the body of text (covering assumptions modulo local
11 definitions); predicate "loc_axioms" covers newly introduced text,
12 while "loc" is cumulative wrt. all included locale expressions; the
13 latter view is presented only on export into the global theory
14 context; potential INCOMPATIBILITY, use "(open)" option to fall back
15 on the old view without predicates;
17 * Pure: predefined locales "var" and "struct" are useful for sharing
18 parameters (as in CASL, for example); just specify something like
19 ``var x + var y + struct M'' as import;
21 * Pure: improved thms_containing: proper indexing of facts instead of
22 raw theorems; check validity of results wrt. current name space;
23 include local facts of proof configuration (also covers active
24 locales), cover fixed variables in index; may use "_" in term
25 specification; an optional limit for the number of printed facts may
26 be given (the default is 40);
28 * Pure: disallow duplicate fact bindings within new-style theory files
31 * Provers: improved induct method: assumptions introduced by case
32 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
33 the goal statement); "foo" still refers to all facts collectively;
35 * Provers: the function blast.overloaded has been removed: all constants
36 are regarded as potentially overloaded, which improves robustness in exchange
37 for slight decrease in efficiency;
39 * Isar: preview of problems to finish 'show' now produce an error
40 rather than just a warning (in interactive mode);
45 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
46 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
48 * 'typedef' command has new option "open" to suppress the set
51 * functions Min and Max on finite sets have been introduced (theory
54 * attribute [symmetric] now works for relations as well; it turns
55 (x,y) : R^-1 into (y,x) : R, and vice versa;
57 * arith(_tac) now produces a counter example if it cannot prove a theorem.
58 In ProofGeneral the counter example appears in the trace buffer.
60 * arith(_tac) does now know about div k and mod k where k is a numeral
61 of type nat or int. It can solve simple goals like
63 "0 < n ==> n div 2 < (n::nat)"
65 but fails if divisibility plays a role like in
67 "n div 2 + (n+1) div 2 = (n::nat)"
69 * simp's arithmetic capabilities have been enhanced a bit: it now
70 takes ~= in premises into account (by performing a case split);
72 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
73 are distributed over a sum of terms;
75 * the simplifier trace now shows the names of the applied rewrite rules
77 * GroupTheory: converted to Isar theories, using locales with implicit structures;
79 * Real/HahnBanach: updated and adapted to locales;
84 * ZF/Constructible: consistency proof for AC (Gödel's constructible
87 * Main ZF: many theories converted to new-style format;
92 * Pure: Tactic.prove provides sane interface for internal proofs;
93 omits the infamous "standard" operation, so this is more appropriate
94 than prove_goalw_cterm in many situations (e.g. in simprocs);
96 * Pure: improved error reporting of simprocs;
98 * Provers: Simplifier.simproc(_i) provides sane interface for setting
103 New in Isabelle2002 (March 2002)
104 --------------------------------
106 *** Document preparation ***
108 * greatly simplified document preparation setup, including more
109 graceful interpretation of isatool usedir -i/-d/-D options, and more
110 instructive isatool mkdir; users should basically be able to get
111 started with "isatool mkdir HOL Test && isatool make"; alternatively,
112 users may run a separate document processing stage manually like this:
113 "isatool usedir -D output HOL Test && isatool document Test/output";
115 * theory dependency graph may now be incorporated into documents;
116 isatool usedir -g true will produce session_graph.eps/.pdf for use
117 with \includegraphics of LaTeX;
119 * proper spacing of consecutive markup elements, especially text
120 blocks after section headings;
122 * support bold style (for single symbols only), input syntax is like
123 this: "\<^bold>\<alpha>" or "\<^bold>A";
125 * \<bullet> is now output as bold \cdot by default, which looks much
126 better in printed text;
128 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
129 note that these symbols are currently unavailable in Proof General /
130 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
132 * isatool latex no longer depends on changed TEXINPUTS, instead
133 isatool document copies the Isabelle style files to the target
139 * Pure/Provers: improved proof by cases and induction;
140 - 'case' command admits impromptu naming of parameters (such as
142 - 'induct' method divinates rule instantiation from the inductive
143 claim; no longer requires excessive ?P bindings for proper
144 instantiation of cases;
145 - 'induct' method properly enumerates all possibilities of set/type
146 rules; as a consequence facts may be also passed through *type*
147 rules without further ado;
148 - 'induct' method now derives symbolic cases from the *rulified*
149 rule (before it used to rulify cases stemming from the internal
150 atomized version); this means that the context of a non-atomic
151 statement becomes is included in the hypothesis, avoiding the
152 slightly cumbersome show "PROP ?case" form;
153 - 'induct' may now use elim-style induction rules without chaining
154 facts, using ``missing'' premises from the goal state; this allows
155 rules stemming from inductive sets to be applied in unstructured
156 scripts, while still benefitting from proper handling of non-atomic
157 statements; NB: major inductive premises need to be put first, all
158 the rest of the goal is passed through the induction;
159 - 'induct' proper support for mutual induction involving non-atomic
160 rule statements (uses the new concept of simultaneous goals, see
162 - append all possible rule selections, but only use the first
163 success (no backtracking);
164 - removed obsolete "(simplified)" and "(stripped)" options of methods;
165 - undeclared rule case names default to numbers 1, 2, 3, ...;
166 - added 'print_induct_rules' (covered by help item in recent Proof
168 - moved induct/cases attributes to Pure, methods to Provers;
169 - generic method setup instantiated for FOL and HOL;
171 * Pure: support multiple simultaneous goal statements, for example
172 "have a: A and b: B" (same for 'theorem' etc.); being a pure
173 meta-level mechanism, this acts as if several individual goals had
174 been stated separately; in particular common proof methods need to be
175 repeated in order to cover all claims; note that a single elimination
176 step is *not* sufficient to establish the two conjunctions, so this
179 assume "A & B" then have A and B .. (*".." fails*)
181 better use "obtain" in situations as above; alternative refer to
182 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
184 * Pure: proper integration with ``locales''; unlike the original
185 version by Florian Kammüller, Isar locales package high-level proof
186 contexts rather than raw logical ones (e.g. we admit to include
187 attributes everywhere); operations on locales include merge and
188 rename; support for implicit arguments (``structures''); simultaneous
189 type-inference over imports and text; see also HOL/ex/Locales.thy for
192 * Pure: the following commands have been ``localized'', supporting a
193 target locale specification "(in name)": 'lemma', 'theorem',
194 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
195 stored both within the locale and at the theory level (exported and
196 qualified by the locale name);
198 * Pure: theory goals may now be specified in ``long'' form, with
199 ad-hoc contexts consisting of arbitrary locale elements. for example
200 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
201 definitions may be given, too); the result is a meta-level rule with
202 the context elements being discharged in the obvious way;
204 * Pure: new proof command 'using' allows to augment currently used
205 facts after a goal statement ('using' is syntactically analogous to
206 'apply', but acts on the goal's facts only); this allows chained facts
207 to be separated into parts given before and after a claim, as in
208 ``from a and b have C using d and e <proof>'';
210 * Pure: renamed "antecedent" case to "rule_context";
212 * Pure: new 'judgment' command records explicit information about the
213 object-logic embedding (used by several tools internally); no longer
214 use hard-wired "Trueprop";
216 * Pure: added 'corollary' command;
218 * Pure: fixed 'token_translation' command;
220 * Pure: removed obsolete 'exported' attribute;
222 * Pure: dummy pattern "_" in is/let is now automatically lifted over
223 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
224 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
226 * Pure: method 'atomize' presents local goal premises as object-level
227 statements (atomic meta-level propositions); setup controlled via
228 rewrite rules declarations of 'atomize' attribute; example
229 application: 'induct' method with proper rule statements in improper
232 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
233 now consider the syntactic context of assumptions, giving a better
234 chance to get type-inference of the arguments right (this is
235 especially important for locales);
237 * Pure: "sorry" no longer requires quick_and_dirty in interactive
240 * Pure/obtain: the formal conclusion "thesis", being marked as
241 ``internal'', may no longer be reference directly in the text;
242 potential INCOMPATIBILITY, may need to use "?thesis" in rare
245 * Pure: generic 'sym' attribute which declares a rule both as pure
246 'elim?' and for the 'symmetric' operation;
248 * Pure: marginal comments ``--'' may now occur just anywhere in the
249 text; the fixed correlation with particular command syntax has been
252 * Pure: new method 'rules' is particularly well-suited for proof
253 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
254 but often produces more compact proof terms with less detours;
256 * Pure/Provers/classical: simplified integration with pure rule
257 attributes and methods; the classical "intro?/elim?/dest?"
258 declarations coincide with the pure ones; the "rule" method no longer
259 includes classically swapped intros; "intro" and "elim" methods no
260 longer pick rules from the context; also got rid of ML declarations
261 AddXIs/AddXEs/AddXDs; all of this has some potential for
264 * Provers/classical: attribute 'swapped' produces classical inversions
265 of introduction rules;
267 * Provers/simplifier: 'simplified' attribute may refer to explicit
268 rules instead of full simplifier context; 'iff' attribute handles
271 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
273 * HOL: 'recdef' now fails on unfinished automated proofs, use
274 "(permissive)" option to recover old behavior;
276 * HOL: 'inductive' no longer features separate (collective) attributes
277 for 'intros' (was found too confusing);
279 * HOL: properly declared induction rules less_induct and
285 * HOL: moved over to sane numeral syntax; the new policy is as
288 - 0 and 1 are polymorphic constants, which are defined on any
289 numeric type (nat, int, real etc.);
291 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
292 binary representation internally;
294 - type nat has special constructor Suc, and generally prefers Suc 0
295 over 1::nat and Suc (Suc 0) over 2::nat;
297 This change may cause significant problems of INCOMPATIBILITY; here
298 are some hints on converting existing sources:
300 - due to the new "num" token, "-0" and "-1" etc. are now atomic
301 entities, so expressions involving "-" (unary or binary minus) need
302 to be spaced properly;
304 - existing occurrences of "1" may need to be constraint "1::nat" or
305 even replaced by Suc 0; similar for old "2";
307 - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
309 - remove all special provisions on numerals in proofs;
311 * HOL: simp rules nat_number expand numerals on nat to Suc/0
312 representation (depends on bin_arith_simps in the default context);
314 * HOL: symbolic syntax for x^2 (numeral 2);
316 * HOL: the class of all HOL types is now called "type" rather than
317 "term"; INCOMPATIBILITY, need to adapt references to this type class
318 in axclass/classes, instance/arities, and (usually rare) occurrences
319 in typings (of consts etc.); internally the class is called
320 "HOL.type", ML programs should refer to HOLogic.typeS;
322 * HOL/record package improvements:
323 - new derived operations "fields" to build a partial record section,
324 "extend" to promote a fixed record to a record scheme, and
325 "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
326 declared as simp by default;
327 - shared operations ("more", "fields", etc.) now need to be always
328 qualified) --- potential INCOMPATIBILITY;
329 - removed "make_scheme" operations (use "make" with "extend") --
331 - removed "more" class (simply use "term") -- INCOMPATIBILITY;
332 - provides cases/induct rules for use with corresponding Isar
333 methods (for concrete records, record schemes, concrete more
334 parts, and schematic more parts -- in that order);
335 - internal definitions directly based on a light-weight abstract
336 theory of product types over typedef rather than datatype;
338 * HOL: generic code generator for generating executable ML code from
339 specifications; specific support for HOL constructs such as inductive
340 datatypes and sets, as well as recursive functions; can be invoked
341 via 'generate_code' theory section;
343 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
345 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
346 (beware of argument permutation!);
348 * HOL: linorder_less_split superseded by linorder_cases;
350 * HOL/List: "nodups" renamed to "distinct";
352 * HOL: added "The" definite description operator; move Hilbert's "Eps"
353 to peripheral theory "Hilbert_Choice";
355 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
356 in this (rare) case use:
358 delSWrapper "split_all_tac"
359 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
361 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
364 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
365 Isabelle's type classes, ^ on functions and relations has too general
366 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
367 necessary to attach explicit type constraints;
369 * HOL/Relation: the prefix name of the infix "O" has been changed from
370 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
371 renamed accordingly (eg "compI" -> "rel_compI").
373 * HOL: syntax translations now work properly with numerals and records
376 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
377 of "lam" -- INCOMPATIBILITY;
379 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
380 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
381 renamed "Product_Type.unit";
383 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
385 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
388 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
391 * HOL/IMP: updated and converted to new-style theory format; several
392 parts turned into readable document, with proper Isar proof texts and
393 some explanations (by Gerwin Klein);
395 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
397 * HOL-Hyperreal is now a logic image;
402 * Isar: consts/constdefs supports mixfix syntax for continuous
405 * Isar: domain package adapted to new-style theory format, e.g. see
408 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
409 potential INCOMPATIBILITY; now use plain induct_tac instead of former
410 lift.induct_tac, always use UU instead of Undef;
412 * HOLCF/IMP: updated and converted to new-style theory;
417 * Isar: proper integration of logic-specific tools and packages,
418 including theory commands '(co)inductive', '(co)datatype',
419 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
420 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
422 * theory Main no longer includes AC; for the Axiom of Choice, base
423 your theory on Main_ZFC;
425 * the integer library now covers quotients and remainders, with many
426 laws relating division to addition, multiplication, etc.;
428 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
429 typeless version of the formalism;
431 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
434 * ZF/Induct: new directory for examples of inductive definitions,
435 including theory Multiset for multiset orderings; converted to
436 new-style theory format;
438 * ZF: many new theorems about lists, ordinals, etc.;
443 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
444 variable proof controls level of detail: 0 = no proofs (only oracle
445 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
446 also ref manual for further ML interfaces;
448 * Pure/axclass: removed obsolete ML interface
449 goal_subclass/goal_arity;
451 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
452 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
453 separate tokens, so expressions involving minus need to be spaced
456 * Pure/syntax: support non-oriented infixes, using keyword "infix"
457 rather than "infixl" or "infixr";
459 * Pure/syntax: concrete syntax for dummy type variables admits genuine
460 sort constraint specifications in type inference; e.g. "x::_::foo"
461 ensures that the type of "x" is of sort "foo" (but not necessarily a
464 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
465 control output of nested => (types); the default behavior is
468 * Pure/syntax: builtin parse translation for "_constify" turns valued
469 tokens into AST constants;
471 * Pure/syntax: prefer later declarations of translations and print
472 translation functions; potential INCOMPATIBILITY: need to reverse
473 multiple declarations for same syntax element constant;
475 * Pure/show_hyps reset by default (in accordance to existing Isar
478 * Provers/classical: renamed addaltern to addafter, addSaltern to
481 * Provers/clasimp: ``iff'' declarations now handle conditional rules
484 * system: tested support for MacOS X; should be able to get Isabelle +
485 Proof General to work in a plain Terminal after installing Poly/ML
486 (e.g. from the Isabelle distribution area) and GNU bash alone
487 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
488 support requires further installations, e.g. from
489 http://fink.sourceforge.net/);
491 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
493 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
494 of 40 MB), cf. ML_OPTIONS;
496 * system: Proof General keywords specification is now part of the
497 Isabelle distribution (see etc/isar-keywords.el);
499 * system: support for persistent Proof General sessions (refrain from
500 outdating all loaded theories on startup); user may create writable
501 logic images like this: ``isabelle -q HOL Test'';
503 * system: smart selection of Isabelle process versus Isabelle
504 interface, accommodates case-insensitive file systems (e.g. HFS+); may
505 run both "isabelle" and "Isabelle" even if file names are badly
506 damaged (executable inspects the case of the first letter of its own
507 name); added separate "isabelle-process" and "isabelle-interface";
509 * system: refrain from any attempt at filtering input streams; no
510 longer support ``8bit'' encoding of old isabelle font, instead proper
511 iso-latin characters may now be used; the related isatools
512 "symbolinput" and "nonascii" have disappeared as well;
514 * system: removed old "xterm" interface (the print modes "xterm" and
515 "xterm_color" are still available for direct use in a suitable
520 New in Isabelle99-2 (February 2001)
521 -----------------------------------
523 *** Overview of INCOMPATIBILITIES ***
525 * HOL: please note that theories in the Library and elsewhere often use the
526 new-style (Isar) format; to refer to their theorems in an ML script you must
527 bind them to ML identifers by e.g. val thm_name = thm "thm_name";
529 * HOL: inductive package no longer splits induction rule aggressively,
530 but only as far as specified by the introductions given; the old
531 format may be recovered via ML function complete_split_rule or attribute
532 'split_rule (complete)';
534 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
535 gfp_Tarski to gfp_unfold;
537 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
539 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
540 relation); infix "^^" has been renamed "``"; infix "``" has been
541 renamed "`"; "univalent" has been renamed "single_valued";
543 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
546 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
548 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
550 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
551 consequence, it is no longer monotonic wrt. the local goal context
552 (which is now passed through the inductive cases);
554 * Document preparation: renamed standard symbols \<ll> to \<lless> and
555 \<gg> to \<ggreater>;
558 *** Document preparation ***
560 * \isabellestyle{NAME} selects version of Isabelle output (currently
561 available: are "it" for near math-mode best-style output, "sl" for
562 slanted text style, and "tt" for plain type-writer; if no
563 \isabellestyle command is given, output is according to slanted
566 * support sub/super scripts (for single symbols only), input syntax is
567 like this: "A\<^sup>*" or "A\<^sup>\<star>";
569 * some more standard symbols; see Appendix A of the system manual for
570 the complete list of symbols defined in isabellesym.sty;
572 * improved isabelle style files; more abstract symbol implementation
573 (should now use \isamath{...} and \isatext{...} in custom symbol
576 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
577 state; Note that presentation of goal states does not conform to
578 actual human-readable proof documents. Please do not include goal
579 states into document output unless you really know what you are doing!
581 * proper indentation of antiquoted output with proportional LaTeX
584 * no_document ML operator temporarily disables LaTeX document
587 * isatool unsymbolize tunes sources for plain ASCII communication;
592 * Pure: Isar now suffers initial goal statements to contain unbound
593 schematic variables (this does not conform to actual readable proof
594 documents, due to unpredictable outcome and non-compositional proof
595 checking); users who know what they are doing may use schematic goals
596 for Prolog-style synthesis of proven results;
598 * Pure: assumption method (an implicit finishing) now handles actual
601 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
602 initial goal, declare "that" only as Pure intro (only for single
603 steps); the "that" rule assumption may now be involved in implicit
604 finishing, thus ".." becomes a feasible for trivial obtains;
606 * Pure: default proof step now includes 'intro_classes'; thus trivial
607 instance proofs may be performed by "..";
609 * Pure: ?thesis / ?this / "..." now work for pure meta-level
612 * Pure: more robust selection of calculational rules;
614 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
615 rule (as well as the assumption rule);
617 * Pure: 'thm_deps' command visualizes dependencies of theorems and
618 lemmas, using the graph browser tool;
620 * Pure: predict failure of "show" in interactive mode;
622 * Pure: 'thms_containing' now takes actual terms as arguments;
624 * HOL: improved method 'induct' --- now handles non-atomic goals
625 (potential INCOMPATIBILITY); tuned error handling;
627 * HOL: cases and induct rules now provide explicit hints about the
628 number of facts to be consumed (0 for "type" and 1 for "set" rules);
629 any remaining facts are inserted into the goal verbatim;
631 * HOL: local contexts (aka cases) may now contain term bindings as
632 well; the 'cases' and 'induct' methods new provide a ?case binding for
633 the result to be shown in each case;
635 * HOL: added 'recdef_tc' command;
637 * isatool convert assists in eliminating legacy ML scripts;
642 * HOL/Library: a collection of generic theories to be used together
643 with main HOL; the theory loader path already includes this directory
644 by default; the following existing theories have been moved here:
645 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
646 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
648 * HOL/Unix: "Some aspects of Unix file-system security", a typical
649 modelling and verification task performed in Isabelle/HOL +
650 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
652 * HOL/Algebra: special summation operator SUM no longer exists, it has
653 been replaced by setsum; infix 'assoc' now has priority 50 (like
654 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
655 'domain', this makes the theory consistent with mathematical
658 * HOL basics: added overloaded operations "inverse" and "divide"
659 (infix "/"), syntax for generic "abs" operation, generic summation
662 * HOL/typedef: simplified package, provide more useful rules (see also
665 * HOL/datatype: induction rule for arbitrarily branching datatypes is
666 now expressed as a proper nested rule (old-style tactic scripts may
667 require atomize_strip_tac to cope with non-atomic premises);
669 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
670 to "split_conv" (old name still available for compatibility);
672 * HOL: improved concrete syntax for strings (e.g. allows translation
673 rules with string literals);
675 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
676 and Fleuriot's mechanization of analysis, including the transcendental
677 functions for the reals;
679 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
684 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
685 "lam" is displayed as TWO lambda-symbols
687 * CTT: theory Main now available, containing everything (that is, Bool
693 * Pure: the Simplifier has been implemented properly as a derived rule
694 outside of the actual kernel (at last!); the overall performance
695 penalty in practical applications is about 50%, while reliability of
696 the Isabelle inference kernel has been greatly improved;
698 * print modes "brackets" and "no_brackets" control output of nested =>
699 (types) and ==> (props); the default behaviour is "brackets";
701 * Provers: fast_tac (and friends) now handle actual object-logic rules
702 as assumptions as well;
704 * system: support Poly/ML 4.0;
706 * system: isatool install handles KDE version 1 or 2;
710 New in Isabelle99-1 (October 2000)
711 ----------------------------------
713 *** Overview of INCOMPATIBILITIES ***
715 * HOL: simplification of natural numbers is much changed; to partly
716 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
717 issue the following ML commands:
719 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
720 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
722 * HOL: simplification no longer dives into case-expressions; this is
723 controlled by "t.weak_case_cong" for each datatype t;
725 * HOL: nat_less_induct renamed to less_induct;
727 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
728 fixsome to patch .thy and .ML sources automatically;
730 select_equality -> some_equality
731 select_eq_Ex -> some_eq_ex
732 selectI2EX -> someI2_ex
735 select1_equality -> some1_equality
736 Eps_sym_eq -> some_sym_eq_trivial
737 Eps_eq -> some_eq_trivial
739 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
741 * HOL: removed obsolete theorem binding expand_if (refer to split_if
744 * HOL: the recursion equations generated by 'recdef' are now called
745 f.simps instead of f.rules;
747 * HOL: qed_spec_mp now also handles bounded ALL as well;
749 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
752 * HOL: the constant for "f``x" is now "image" rather than "op ``";
754 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
756 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
757 product is now "<*>" instead of "Times"; the lexicographic product is
758 now "<*lex*>" instead of "**";
760 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
761 of main HOL, but was unused); better use HOL's datatype package;
763 * HOL: removed "symbols" syntax for constant "override" of theory Map;
764 the old syntax may be recovered as follows:
767 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
768 (infixl "\\<oplus>" 100)
770 * HOL/Real: "rabs" replaced by overloaded "abs" function;
772 * HOL/ML: even fewer consts are declared as global (see theories Ord,
773 Lfp, Gfp, WF); this only affects ML packages that refer to const names
776 * HOL and ZF: syntax for quotienting wrt an equivalence relation
777 changed from A/r to A//r;
779 * ZF: new treatment of arithmetic (nat & int) may break some old
782 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
783 rulify -> rule_format, elimify -> elim_format, ...);
785 * Isar/Provers: intro/elim/dest attributes changed; renamed
786 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
787 should have to change intro!! to intro? only); replaced "delrule" by
790 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
792 * Provers: strengthened force_tac by using new first_best_tac;
794 * LaTeX document preparation: several changes of isabelle.sty (see
798 *** Document preparation ***
800 * formal comments (text blocks etc.) in new-style theories may now
801 contain antiquotations of thm/prop/term/typ/text to be presented
802 according to latex print mode; concrete syntax is like this:
803 @{term[show_types] "f(x) = a + x"};
805 * isatool mkdir provides easy setup of Isabelle session directories,
806 including proper document sources;
808 * generated LaTeX sources are now deleted after successful run
809 (isatool document -c); may retain a copy somewhere else via -D option
812 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
813 style files, achieving self-contained LaTeX sources and simplifying
816 * old-style theories now produce (crude) LaTeX output as well;
818 * browser info session directories are now self-contained (may be put
819 on WWW server seperately); improved graphs of nested sessions; removed
820 graph for 'all sessions';
822 * several improvements in isabelle style files; \isabellestyle{it}
823 produces fake math mode output; \isamarkupheader is now \section by
824 default; see lib/texinputs/isabelle.sty etc.;
829 * Isar/Pure: local results and corresponding term bindings are now
830 subject to Hindley-Milner polymorphism (similar to ML); this
831 accommodates incremental type-inference very nicely;
833 * Isar/Pure: new derived language element 'obtain' supports
834 generalized existence reasoning;
836 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
837 support accumulation of results, without applying any rules yet;
838 useful to collect intermediate results without explicit name
839 references, and for use with transitivity rules with more than 2
842 * Isar/Pure: scalable support for case-analysis type proofs: new
843 'case' language element refers to local contexts symbolically, as
844 produced by certain proof methods; internally, case names are attached
845 to theorems as "tags";
847 * Isar/Pure: theory command 'hide' removes declarations from
848 class/type/const name spaces;
850 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
851 indicate potential overloading;
853 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
855 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
856 "{a,b,c}" instead of {a,b,c};
858 * Isar/Pure now provides its own version of intro/elim/dest
859 attributes; useful for building new logics, but beware of confusion
860 with the version in Provers/classical;
862 * Isar/Pure: the local context of (non-atomic) goals is provided via
863 case name 'antecedent';
865 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
866 to the current context is now done automatically);
868 * Isar/Pure: theory command 'method_setup' provides a simple interface
869 for definining proof methods in ML;
871 * Isar/Provers: intro/elim/dest attributes changed; renamed
872 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
873 most cases, one should have to change intro!! to intro? only);
874 replaced "delrule" by "rule del";
876 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
877 'symmetric' attribute (the latter supercedes [RS sym]);
879 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
880 method modifier); 'simp' method: 'only:' modifier removes loopers as
881 well (including splits);
883 * Isar/Provers: Simplifier and Classical methods now support all kind
884 of modifiers used in the past, including 'cong', 'iff', etc.
886 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
887 of Simplifier and Classical reasoner);
889 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
890 now support named cases; major packages (inductive, datatype, primrec,
891 recdef) support case names and properly name parameters;
893 * Isar/HOL: new transitivity rules for substitution in inequalities --
894 monotonicity conditions are extracted to be proven at end of
897 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
900 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
901 split_if split_if_asm; datatype package provides theorems foo.splits =
902 foo.split foo.split_asm for each datatype;
904 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
905 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
906 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
907 use "(cases (simplified))" method in proper proof texts);
909 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
911 * Isar: names of theorems etc. may be natural numbers as well;
913 * Isar: 'pr' command: optional arguments for goals_limit and
914 ProofContext.prems_limit; no longer prints theory contexts, but only
917 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
918 additional print modes to be specified; e.g. "pr(latex)" will print
919 proof state according to the Isabelle LaTeX style;
921 * Isar: improved support for emulating tactic scripts, including proof
922 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
923 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
926 * Isar: simplified (more robust) goal selection of proof methods: 1st
927 goal, all goals, or explicit goal specifier (tactic emulation); thus
928 'proof method scripts' have to be in depth-first order;
930 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
932 * Isar: removed 'help' command, which hasn't been too helpful anyway;
933 should instead use individual commands for printing items
934 (print_commands, print_methods etc.);
936 * Isar: added 'nothing' --- the empty list of theorems;
941 * HOL/MicroJava: formalization of a fragment of Java, together with a
942 corresponding virtual machine and a specification of its bytecode
943 verifier and a lightweight bytecode verifier, including proofs of
944 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
945 Cornelia Pusch (see also the homepage of project Bali at
946 http://isabelle.in.tum.de/Bali/);
948 * HOL/Algebra: new theory of rings and univariate polynomials, by
951 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
952 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
955 * HOL/Lattice: fundamental concepts of lattice theory and order
956 structures, including duals, properties of bounds versus algebraic
957 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
958 Theorem for complete lattices etc.; may also serve as a demonstration
959 for abstract algebraic reasoning using axiomatic type classes, and
960 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
962 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
965 * HOL/IMPP: extension of IMP with local variables and mutually
966 recursive procedures, by David von Oheimb;
968 * HOL/Lambda: converted into new-style theory and document;
970 * HOL/ex/Multiquote: example of multiple nested quotations and
971 anti-quotations -- basically a generalized version of de-Bruijn
972 representation; very useful in avoiding lifting of operations;
974 * HOL/record: added general record equality rule to simpset; fixed
975 select-update simplification procedure to handle extended records as
976 well; admit "r" as field name;
978 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
979 other numeric types and also as the identity of groups, rings, etc.;
981 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
982 Types nat and int belong to this axclass;
984 * HOL: greatly improved simplification involving numerals of type nat, int, real:
985 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k
986 i*j + k + j*#3*i simplifies to #4*(i*j) + k
987 two terms #m*u and #n*u are replaced by #(m+n)*u
988 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
989 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
990 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
992 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
993 powerful prover for predicate logic but knows nothing of clasets; see
994 ex/mesontest.ML and ex/mesontest2.ML for example applications;
996 * HOL: new version of "case_tac" subsumes both boolean case split and
997 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
998 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
1000 * HOL: simplification no longer dives into case-expressions: only the
1001 selector expression is simplified, but not the remaining arms; to
1002 enable full simplification of case-expressions for datatype t, you may
1003 remove t.weak_case_cong from the simpset, either globally (Delcongs
1004 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
1006 * HOL/recdef: the recursion equations generated by 'recdef' for
1007 function 'f' are now called f.simps instead of f.rules; if all
1008 termination conditions are proved automatically, these simplification
1009 rules are added to the simpset, as in primrec; rules may be named
1010 individually as well, resulting in a separate list of theorems for
1013 * HOL/While is a new theory that provides a while-combinator. It
1014 permits the definition of tail-recursive functions without the
1015 provision of a termination measure. The latter is necessary once the
1016 invariant proof rule for while is applied.
1018 * HOL: new (overloaded) notation for the set of elements below/above
1019 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
1021 * HOL: theorems impI, allI, ballI bound as "strip";
1023 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
1024 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
1025 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
1027 * HOL/Real: "rabs" replaced by overloaded "abs" function;
1029 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
1030 main HOL, but was unused);
1032 * HOL: fewer consts declared as global (e.g. have to refer to
1033 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
1035 * HOL: tuned AST representation of nested pairs, avoiding bogus output
1036 in case of overlap with user translations (e.g. judgements over
1037 tuples); (note that the underlying logical represenation is still
1043 * ZF: simplification automatically cancels common terms in arithmetic
1044 expressions over nat and int;
1046 * ZF: new treatment of nat to minimize type-checking: all operators
1047 coerce their operands to a natural number using the function natify,
1048 making the algebraic laws unconditional;
1050 * ZF: as above, for int: operators coerce their operands to an integer
1051 using the function intify;
1053 * ZF: the integer library now contains many of the usual laws for the
1054 orderings, including $<=, and monotonicity laws for $+ and $*;
1056 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
1059 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
1060 to the simplifier and classical reasoner simultaneously;
1065 * Provers: blast_tac now handles actual object-logic rules as
1066 assumptions; note that auto_tac uses blast_tac internally as well;
1068 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
1069 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
1071 * Provers: delrules now handles destruct rules as well (no longer need
1072 explicit make_elim);
1074 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
1075 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
1076 use instead the strong form,
1077 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
1078 in HOL, FOL and ZF the function cla_make_elim will create such rules
1079 from destruct-rules;
1081 * Provers: Simplifier.easy_setup provides a fast path to basic
1082 Simplifier setup for new object-logics;
1084 * Pure: AST translation rules no longer require constant head on LHS;
1086 * Pure: improved name spaces: ambiguous output is qualified; support
1087 for hiding of names;
1089 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
1090 XSYMBOL_HOME; no longer need to do manual configuration in most
1093 * system: compression of ML heaps images may now be controlled via -c
1094 option of isabelle and isatool usedir (currently only observed by
1097 * system: isatool installfonts may handle X-Symbol fonts as well (very
1098 useful for remote X11);
1100 * system: provide TAGS file for Isabelle sources;
1102 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
1105 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
1106 timing flag supersedes proof_timing and Toplevel.trace;
1108 * ML: new combinators |>> and |>>> for incremental transformations
1109 with secondary results (e.g. certain theory extensions):
1111 * ML: PureThy.add_defs gets additional argument to indicate potential
1112 overloading (usually false);
1114 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
1119 New in Isabelle99 (October 1999)
1120 --------------------------------
1122 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1124 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
1125 are no longer simplified. (This allows the simplifier to unfold recursive
1126 functional programs.) To restore the old behaviour, declare
1128 Delcongs [if_weak_cong];
1130 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
1133 * HOL: the predicate "inj" is now defined by translation to "inj_on";
1135 * HOL/datatype: mutual_induct_tac no longer exists --
1136 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
1138 * HOL/typedef: fixed type inference for representing set; type
1139 arguments now have to occur explicitly on the rhs as type constraints;
1141 * ZF: The con_defs part of an inductive definition may no longer refer
1142 to constants declared in the same theory;
1144 * HOL, ZF: the function mk_cases, generated by the inductive
1145 definition package, has lost an argument. To simplify its result, it
1146 uses the default simpset instead of a supplied list of theorems.
1148 * HOL/List: the constructors of type list are now Nil and Cons;
1150 * Simplifier: the type of the infix ML functions
1151 setSSolver addSSolver setSolver addSolver
1152 is now simpset * solver -> simpset where `solver' is a new abstract type
1153 for packaging solvers. A solver is created via
1154 mk_solver: string -> (thm list -> int -> tactic) -> solver
1155 where the string argument is only a comment.
1160 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
1161 decision procedure for linear arithmetic. Currently it is used for
1162 types `nat', `int', and `real' in HOL (see below); it can, should and
1163 will be instantiated for other types and logics as well.
1165 * The simplifier now accepts rewrite rules with flexible heads, eg
1166 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
1167 They are applied like any rule with a non-pattern lhs, i.e. by first-order
1173 * New Isabelle/Isar subsystem provides an alternative to traditional
1174 tactical theorem proving; together with the ProofGeneral/isar user
1175 interface it offers an interactive environment for developing human
1176 readable proof documents (Isar == Intelligible semi-automated
1177 reasoning); for further information see isatool doc isar-ref,
1178 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
1180 * improved and simplified presentation of theories: better HTML markup
1181 (including colors), graph views in several sizes; isatool usedir now
1182 provides a proper interface for user theories (via -P option); actual
1183 document preparation based on (PDF)LaTeX is available as well (for
1184 new-style theories only); see isatool doc system for more information;
1186 * native support for Proof General, both for classic Isabelle and
1189 * ML function thm_deps visualizes dependencies of theorems and lemmas,
1190 using the graph browser tool;
1192 * Isabelle manuals now also available as PDF;
1194 * theory loader rewritten from scratch (may not be fully
1195 bug-compatible); old loadpath variable has been replaced by show_path,
1196 add_path, del_path, reset_path functions; new operations such as
1197 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
1200 * improved isatool install: option -k creates KDE application icon,
1201 option -p DIR installs standalone binaries;
1203 * added ML_PLATFORM setting (useful for cross-platform installations);
1204 more robust handling of platform specific ML images for SML/NJ;
1206 * the settings environment is now statically scoped, i.e. it is never
1207 created again in sub-processes invoked from isabelle, isatool, or
1210 * path element specification '~~' refers to '$ISABELLE_HOME';
1212 * in locales, the "assumes" and "defines" parts may be omitted if
1215 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
1218 * new print_mode "HTML";
1220 * new flag show_tags controls display of tags of theorems (which are
1221 basically just comments that may be attached by some tools);
1223 * Isamode 2.6 requires patch to accomodate change of Isabelle font
1224 mode and goal output format:
1226 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
1228 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
1230 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
1231 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
1233 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
1235 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
1237 * function bind_thms stores lists of theorems (cf. bind_thm);
1239 * new shorthand tactics ftac, eatac, datac, fatac;
1241 * qed (and friends) now accept "" as result name; in that case the
1242 theorem is not stored, but proper checks and presentation of the
1245 * theorem database now also indexes constants "Trueprop", "all",
1246 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
1251 ** HOL arithmetic **
1253 * There are now decision procedures for linear arithmetic over nat and
1256 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
1257 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
1258 are treated as atomic; subformulae not involving type `nat' or `int'
1259 are ignored; quantified subformulae are ignored unless they are
1260 positive universal or negative existential. The tactic has to be
1261 invoked by hand and can be a little bit slow. In particular, the
1262 running time is exponential in the number of occurrences of `min' and
1263 `max', and `-' on `nat'.
1265 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
1266 (negated) (in)equalities among the premises and the conclusion into
1267 account (i.e. no compound formulae) and does not know about `min' and
1268 `max', and `-' on `nat'. It is fast and is used automatically by the
1271 NB: At the moment, these decision procedures do not cope with mixed
1272 nat/int formulae where the two parts interact, such as `m < n ==>
1275 * HOL/Numeral provides a generic theory of numerals (encoded
1276 efficiently as bit strings); setup for types nat/int/real is in place;
1277 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
1278 int, existing theories and proof scripts may require a few additional
1281 * integer division and remainder can now be performed on constant
1284 * many properties of integer multiplication, division and remainder
1287 * An interface to the Stanford Validity Checker (SVC) is available through the
1288 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic
1289 are proved automatically. SVC must be installed separately, and its results
1290 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
1291 invocation of the underlying oracle). For SVC see
1292 http://verify.stanford.edu/SVC
1294 * IsaMakefile: the HOL-Real target now builds an actual image;
1299 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
1300 (in Isabelle/Isar) -- by Gertrud Bauer;
1302 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
1303 analysis for assembly languages with subtypes;
1305 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
1306 -- avoids syntactic ambiguities and treats state, transition, and
1307 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
1308 changed syntax and (many) tactics;
1310 * HOL/inductive: Now also handles more general introduction rules such
1311 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
1312 theorems are now maintained within the theory (maintained via the
1315 * HOL/datatype: Now also handles arbitrarily branching datatypes
1316 (using function types) such as
1318 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
1320 * HOL/record: record_simproc (part of the default simpset) takes care
1321 of selectors applied to updated records; record_split_tac is no longer
1322 part of the default claset; update_defs may now be removed from the
1323 simpset in many cases; COMPATIBILITY: old behavior achieved by
1325 claset_ref () := claset() addSWrapper record_split_wrapper;
1326 Delsimprocs [record_simproc]
1328 * HOL/typedef: fixed type inference for representing set; type
1329 arguments now have to occur explicitly on the rhs as type constraints;
1331 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
1332 names rather than an ML expression;
1334 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
1335 supplied later. Program schemes can be defined, such as
1336 "While B C s = (if B s then While B C (C s) else s)"
1337 where the well-founded relation can be chosen after B and C have been given.
1339 * HOL/List: the constructors of type list are now Nil and Cons;
1340 INCOMPATIBILITY: while [] and infix # syntax is still there, of
1341 course, ML tools referring to List.list.op # etc. have to be adapted;
1343 * HOL_quantifiers flag superseded by "HOL" print mode, which is
1344 disabled by default; run isabelle with option -m HOL to get back to
1345 the original Gordon/HOL-style output;
1347 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
1348 ALL x<=y. P, EX x<y. P, EX x<=y. P;
1350 * HOL basic syntax simplified (more orthogonal): all variants of
1351 All/Ex now support plain / symbolic / HOL notation; plain syntax for
1352 Eps operator is provided as well: "SOME x. P[x]";
1354 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
1356 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
1357 thus available for user theories;
1359 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
1360 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
1363 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
1364 several times and then mp;
1369 * the notation <<...>> is now available as a notation for sequences of
1372 * the simplifier is now installed
1374 * the axiom system has been generalized (thanks to Soren Heilmann)
1376 * the classical reasoner now has a default rule database
1381 * new primrec section allows primitive recursive functions to be given
1382 directly (as in HOL) over datatypes and the natural numbers;
1384 * new tactics induct_tac and exhaust_tac for induction (or case
1385 analysis) over datatypes and the natural numbers;
1387 * the datatype declaration of type T now defines the recursor T_rec;
1389 * simplification automatically does freeness reasoning for datatype
1392 * automatic type-inference, with AddTCs command to insert new
1393 type-checking rules;
1395 * datatype introduction rules are now added as Safe Introduction rules
1398 * the syntax "if P then x else y" is now available in addition to
1402 *** Internal programming interfaces ***
1404 * tuned simplifier trace output; new flag debug_simp;
1406 * structures Vartab / Termtab (instances of TableFun) offer efficient
1407 tables indexed by indexname_ord / term_ord (compatible with aconv);
1409 * AxClass.axclass_tac lost the theory argument;
1411 * tuned current_goals_markers semantics: begin / end goal avoids
1412 printing empty lines;
1414 * removed prs and prs_fn hook, which was broken because it did not
1415 include \n in its semantics, forcing writeln to add one
1416 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
1417 string -> unit if you really want to output text without newline;
1419 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
1420 plain output, interface builders may have to enable 'isabelle_font'
1421 mode to get Isabelle font glyphs as before;
1423 * refined token_translation interface; INCOMPATIBILITY: output length
1424 now of type real instead of int;
1426 * theory loader actions may be traced via new ThyInfo.add_hook
1427 interface (see src/Pure/Thy/thy_info.ML); example application: keep
1428 your own database of information attached to *whole* theories -- as
1429 opposed to intra-theory data slots offered via TheoryDataFun;
1431 * proper handling of dangling sort hypotheses (at last!);
1432 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
1433 extra sort hypotheses that can be witnessed from the type signature;
1434 the force_strip_shyps flag is gone, any remaining shyps are simply
1435 left in the theorem (with a warning issued by strip_shyps_warning);
1439 New in Isabelle98-1 (October 1998)
1440 ----------------------------------
1442 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1444 * several changes of automated proof tools;
1446 * HOL: major changes to the inductive and datatype packages, including
1447 some minor incompatibilities of theory syntax;
1449 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
1452 * HOL: removed duplicate thms in Arith:
1453 less_imp_add_less should be replaced by trans_less_add1
1454 le_imp_add_le should be replaced by trans_le_add1
1456 * HOL: unary minus is now overloaded (new type constraints may be
1459 * HOL and ZF: unary minus for integers is now #- instead of #~. In
1460 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
1461 now taken as an integer constant.
1463 * Pure: ML function 'theory_of' renamed to 'theory';
1469 1. Asm_full_simp_tac is now more aggressive.
1470 1. It will sometimes reorient premises if that increases their power to
1472 2. It does no longer proceed strictly from left to right but may also
1473 rotate premises to achieve further simplification.
1474 For compatibility reasons there is now Asm_lr_simp_tac which is like the
1475 old Asm_full_simp_tac in that it does not rotate premises.
1476 2. The simplifier now knows a little bit about nat-arithmetic.
1478 * Classical reasoner: wrapper mechanism for the classical reasoner now
1479 allows for selected deletion of wrappers, by introduction of names for
1480 wrapper functionals. This implies that addbefore, addSbefore,
1481 addaltern, and addSaltern now take a pair (name, tactic) as argument,
1482 and that adding two tactics with the same name overwrites the first
1483 one (emitting a warning).
1484 type wrapper = (int -> tactic) -> (int -> tactic)
1485 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
1486 addWrapper, addSWrapper: claset * (string * wrapper) -> claset
1487 delWrapper, delSWrapper: claset * string -> claset
1488 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
1490 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
1491 semantics; addbefore now affects only the unsafe part of step_tac
1492 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
1493 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
1496 * Classical reasoner: setwrapper to setWrapper and compwrapper to
1497 compWrapper; added safe wrapper (and access functions for it);
1499 * HOL/split_all_tac is now much faster and fails if there is nothing
1500 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
1501 and the names of the automatically generated variables have changed.
1502 split_all_tac has moved within claset() from unsafe wrappers to safe
1503 wrappers, which means that !!-bound variables are split much more
1504 aggressively, and safe_tac and clarify_tac now split such variables.
1505 If this splitting is not appropriate, use delSWrapper "split_all_tac".
1506 Note: the same holds for record_split_tac, which does the job of
1507 split_all_tac for record fields.
1509 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
1510 permanently to the default simpset using Addsplits just like
1511 Addsimps. They can be removed via Delsplits just like
1512 Delsimps. Lower-case versions are also available.
1514 * HOL/Simplifier: The rule split_if is now part of the default
1515 simpset. This means that the simplifier will eliminate all occurrences
1516 of if-then-else in the conclusion of a goal. To prevent this, you can
1517 either remove split_if completely from the default simpset by
1518 `Delsplits [split_if]' or remove it in a specific call of the
1519 simplifier using `... delsplits [split_if]'. You can also add/delete
1520 other case splitting rules to/from the default simpset: every datatype
1521 generates suitable rules `split_t_case' and `split_t_case_asm' (where
1522 t is the name of the datatype).
1524 * Classical reasoner / Simplifier combination: new force_tac (and
1525 derivatives Force_tac, force) combines rewriting and classical
1526 reasoning (and whatever other tools) similarly to auto_tac, but is
1527 aimed to solve the given subgoal completely.
1532 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
1533 and `goalw': the theory is no longer needed as an explicit argument -
1534 the current theory context is used; assumptions are no longer returned
1535 at the ML-level unless one of them starts with ==> or !!; it is
1536 recommended to convert to these new commands using isatool fixgoal
1537 (backup your sources first!);
1539 * new top-level commands 'thm' and 'thms' for retrieving theorems from
1540 the current theory context, and 'theory' to lookup stored theories;
1542 * new theory section 'locale' for declaring constants, assumptions and
1543 definitions that have local scope;
1545 * new theory section 'nonterminals' for purely syntactic types;
1547 * new theory section 'setup' for generic ML setup functions
1548 (e.g. package initialization);
1550 * the distribution now includes Isabelle icons: see
1551 lib/logo/isabelle-{small,tiny}.xpm;
1553 * isatool install - install binaries with absolute references to
1556 * isatool logo -- create instances of the Isabelle logo (as EPS);
1558 * print mode 'emacs' reserved for Isamode;
1560 * support multiple print (ast) translations per constant name;
1562 * theorems involving oracles are now printed with a suffixed [!];
1567 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
1569 * HOL/inductive package reorganized and improved: now supports mutual
1575 oddI "n : EVEN ==> Suc n : ODD"
1576 evenI "n : ODD ==> Suc n : EVEN"
1578 new theorem list "elims" contains an elimination rule for each of the
1579 recursive sets; inductive definitions now handle disjunctive premises
1580 correctly (also ZF);
1582 INCOMPATIBILITIES: requires Inductive as an ancestor; component
1583 "mutual_induct" no longer exists - the induction rule is always
1584 contained in "induct";
1587 * HOL/datatype package re-implemented and greatly improved: now
1588 supports mutually recursive datatypes such as
1591 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
1592 | SUM ('a aexp) ('a aexp)
1593 | DIFF ('a aexp) ('a aexp)
1596 'a bexp = LESS ('a aexp) ('a aexp)
1597 | AND ('a bexp) ('a bexp)
1598 | OR ('a bexp) ('a bexp)
1600 as well as indirectly recursive datatypes such as
1603 ('a, 'b) term = Var 'a
1604 | App 'b ((('a, 'b) term) list)
1606 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs
1607 induction on mutually / indirectly recursive datatypes.
1609 Primrec equations are now stored in theory and can be accessed via
1610 <function_name>.simps.
1614 - Theories using datatypes must now have theory Datatype as an
1616 - The specific <typename>.induct_tac no longer exists - use the
1617 generic induct_tac instead.
1618 - natE has been renamed to nat.exhaust - use exhaust_tac
1619 instead of res_inst_tac ... natE. Note that the variable
1620 names in nat.exhaust differ from the names in natE, this
1621 may cause some "fragile" proofs to fail.
1622 - The theorems split_<typename>_case and split_<typename>_case_asm
1623 have been renamed to <typename>.split and <typename>.split_asm.
1624 - Since default sorts of type variables are now handled correctly,
1625 some datatype definitions may have to be annotated with explicit
1627 - Primrec definitions no longer require function name and type
1628 of recursive argument.
1630 Consider using isatool fixdatatype to adapt your theories and proof
1631 scripts to the new package (backup your sources first!).
1634 * HOL/record package: considerably improved implementation; now
1635 includes concrete syntax for record types, terms, updates; theorems
1636 for surjective pairing and splitting !!-bound record variables; proof
1637 support is as follows:
1639 1) standard conversions (selectors or updates applied to record
1640 constructor terms) are part of the standard simpset;
1642 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
1643 made part of standard simpset and claset via addIffs;
1645 3) a tactic for record field splitting (record_split_tac) is part of
1646 the standard claset (addSWrapper);
1648 To get a better idea about these rules you may retrieve them via
1649 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
1650 the name of your record type.
1652 The split tactic 3) conceptually simplifies by the following rule:
1654 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
1656 Thus any record variable that is bound by meta-all will automatically
1657 blow up into some record constructor term, consequently the
1658 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall
1659 solve record problems automatically.
1662 * reorganized the main HOL image: HOL/Integ and String loaded by
1663 default; theory Main includes everything;
1665 * automatic simplification of integer sums and comparisons, using cancellation;
1667 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
1669 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
1671 * many new identities for unions, intersections, set difference, etc.;
1673 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
1674 called split_if, split_split, split_sum_case and split_nat_case (to go
1675 with add/delsplits);
1677 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
1678 (?x::unit) = (); this is made part of the default simpset, which COULD
1679 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
1680 'Delsimprocs [unit_eq_proc];' as last resort); also note that
1681 unit_abs_eta_conv is added in order to counter the effect of
1682 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
1685 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
1688 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1689 It and 'sym RS equals0D' are now in the default claset, giving automatic
1690 disjointness reasoning but breaking a few old proofs.
1692 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
1693 to 'converse' from 'inverse' (for compatibility with ZF and some
1696 * HOL/recdef can now declare non-recursive functions, with {} supplied as
1697 the well-founded relation;
1699 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
1700 Compl A. The "Compl" syntax remains available as input syntax for this
1703 * HOL/Update: new theory of function updates:
1704 f(a:=b) == %x. if x=a then b else f x
1705 may also be iterated as in f(a:=b,c:=d,...);
1707 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
1710 - new function list_update written xs[i:=v] that updates the i-th
1711 list position. May also be iterated as in xs[i:=a,j:=b,...].
1712 - new function `upt' written [i..j(] which generates the list
1713 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
1714 bound write [i..j], which is a shorthand for [i..j+1(].
1715 - new lexicographic orderings and corresponding wellfoundedness theorems.
1718 - removed 'pred' (predecessor) function;
1719 - generalized some theorems about n-1;
1720 - many new laws about "div" and "mod";
1721 - new laws about greatest common divisors (see theory ex/Primes);
1723 * HOL/Relation: renamed the relational operator r^-1 "converse"
1724 instead of "inverse";
1726 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
1727 of the multiset ordering;
1729 * directory HOL/Real: a construction of the reals using Dedekind cuts
1730 (not included by default);
1732 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
1734 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
1735 programs, i.e. different program variables may have different types.
1737 * calling (stac rew i) now fails if "rew" has no effect on the goal
1738 [previously, this check worked only if the rewrite rule was unconditional]
1739 Now rew can involve either definitions or equalities (either == or =).
1744 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
1745 only the theorems proved on ZF.ML;
1747 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1748 It and 'sym RS equals0D' are now in the default claset, giving automatic
1749 disjointness reasoning but breaking a few old proofs.
1751 * ZF/Update: new theory of function updates
1752 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)
1753 may also be iterated as in f(a:=b,c:=d,...);
1755 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.
1757 * calling (stac rew i) now fails if "rew" has no effect on the goal
1758 [previously, this check worked only if the rewrite rule was unconditional]
1759 Now rew can involve either definitions or equalities (either == or =).
1761 * case_tac provided for compatibility with HOL
1762 (like the old excluded_middle_tac, but with subgoals swapped)
1765 *** Internal programming interfaces ***
1767 * Pure: several new basic modules made available for general use, see
1768 also src/Pure/README;
1770 * improved the theory data mechanism to support encapsulation (data
1771 kind name replaced by private Object.kind, acting as authorization
1772 key); new type-safe user interface via functor TheoryDataFun; generic
1773 print_data function becomes basically useless;
1775 * removed global_names compatibility flag -- all theory declarations
1776 are qualified by default;
1778 * module Pure/Syntax now offers quote / antiquote translation
1779 functions (useful for Hoare logic etc. with implicit dependencies);
1780 see HOL/ex/Antiquote for an example use;
1782 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
1785 * new tactical CHANGED_GOAL for checking that a tactic modifies a
1788 * Display.print_goals function moved to Locale.print_goals;
1790 * standard print function for goals supports current_goals_markers
1791 variable for marking begin of proof, end of proof, start of goal; the
1792 default is ("", "", ""); setting current_goals_markers := ("<proof>",
1793 "</proof>", "<goal>") causes SGML like tagged proof state printing,
1798 New in Isabelle98 (January 1998)
1799 --------------------------------
1801 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1803 * changed lexical syntax of terms / types: dots made part of long
1804 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
1806 * simpset (and claset) reference variable replaced by functions
1807 simpset / simpset_ref;
1809 * no longer supports theory aliases (via merge) and non-trivial
1810 implicit merge of thms' signatures;
1812 * most internal names of constants changed due to qualified names;
1814 * changed Pure/Sequence interface (see Pure/seq.ML);
1817 *** General Changes ***
1819 * hierachically structured name spaces (for consts, types, axms, thms
1820 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
1821 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
1822 isatool fixdots ensures space after dots (e.g. "%x. x"); set
1823 long_names for fully qualified output names; NOTE: ML programs
1824 (special tactics, packages etc.) referring to internal names may have
1825 to be adapted to cope with fully qualified names; in case of severe
1826 backward campatibility problems try setting 'global_names' at compile
1827 time to have enrything declared within a flat name space; one may also
1828 fine tune name declarations in theories via the 'global' and 'local'
1831 * reimplemented the implicit simpset and claset using the new anytype
1832 data filed in signatures; references simpset:simpset ref etc. are
1833 replaced by functions simpset:unit->simpset and
1834 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
1835 to patch your ML files accordingly;
1837 * HTML output now includes theory graph data for display with Java
1838 applet or isatool browser; data generated automatically via isatool
1839 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
1841 * defs may now be conditional; improved rewrite_goals_tac to handle
1842 conditional equations;
1844 * defs now admits additional type arguments, using TYPE('a) syntax;
1846 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
1847 creates a new theory node; implicit merge of thms' signatures is
1848 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
1849 transfer:theory->thm->thm in (rare) cases;
1851 * improved handling of draft signatures / theories; draft thms (and
1852 ctyps, cterms) are automatically promoted to real ones;
1854 * slightly changed interfaces for oracles: admit many per theory, named
1855 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
1857 * print_goals: optional output of const types (set show_consts and
1860 * improved output of warnings (###) and errors (***);
1862 * subgoal_tac displays a warning if the new subgoal has type variables;
1864 * removed old README and Makefiles;
1866 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
1868 * removed obsolete init_pps and init_database;
1870 * deleted the obsolete tactical STATE, which was declared by
1871 fun STATE tacfun st = tacfun st st;
1873 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
1874 (which abbreviates $HOME);
1876 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
1877 use isatool fixseq to adapt your ML programs (this works for fully
1878 qualified references to the Sequence structure only!);
1880 * use_thy no longer requires writable current directory; it always
1881 reloads .ML *and* .thy file, if either one is out of date;
1884 *** Classical Reasoner ***
1886 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
1887 tactics that use classical reasoning to simplify a subgoal without
1888 splitting it into several subgoals;
1890 * Safe_tac: like safe_tac but uses the default claset;
1895 * added simplification meta rules:
1896 (asm_)(full_)simplify: simpset -> thm -> thm;
1898 * simplifier.ML no longer part of Pure -- has to be loaded by object
1901 * added prems argument to simplification procedures;
1903 * HOL, FOL, ZF: added infix function `addsplits':
1904 instead of `<simpset> setloop (split_tac <thms>)'
1905 you can simply write `<simpset> addsplits <thms>'
1910 * TYPE('a) syntax for type reflection terms;
1912 * no longer handles consts with name "" -- declare as 'syntax' instead;
1914 * pretty printer: changed order of mixfix annotation preference (again!);
1916 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
1921 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
1922 with `addloop' of the simplifier to faciliate case splitting in premises.
1924 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
1926 * HOL/Auth: new protocol proofs including some for the Internet
1929 * HOL/Map: new theory of `maps' a la VDM;
1931 * HOL/simplifier: simplification procedures nat_cancel_sums for
1932 cancelling out common nat summands from =, <, <= (in)equalities, or
1933 differences; simplification procedures nat_cancel_factor for
1934 cancelling common factor from =, <, <= (in)equalities over natural
1935 sums; nat_cancel contains both kinds of procedures, it is installed by
1936 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
1938 * HOL/simplifier: terms of the form
1939 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)
1941 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
1942 and those of the form
1943 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)
1945 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
1948 Each datatype `t' now comes with a theorem `split_t_case' of the form
1950 P(t_case f1 ... fn x) =
1951 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
1953 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
1956 and a theorem `split_t_case_asm' of the form
1958 P(t_case f1 ... fn x) =
1959 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
1961 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
1963 which can be added to a simpset via `addsplits'. The existing theorems
1964 expand_list_case and expand_option_case have been renamed to
1965 split_list_case and split_option_case.
1968 - `pred n' is automatically converted to `n-1'.
1969 Users are strongly encouraged not to use `pred' any longer,
1970 because it will disappear altogether at some point.
1971 - Users are strongly encouraged to write "0 < n" rather than
1972 "n ~= 0". Theorems and proof tools have been modified towards this
1976 the function "set_of_list" has been renamed "set" (and its theorems too);
1977 the function "nth" now takes its arguments in the reverse order and
1978 has acquired the infix notation "!" as in "xs!n".
1980 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
1982 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
1983 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);
1985 * HOL/record: extensible records with schematic structural subtyping
1986 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
1987 still lacks various theorems and concrete record syntax;
1992 * removed "axioms" and "generated by" sections;
1994 * replaced "ops" section by extended "consts" section, which is capable of
1995 handling the continuous function space "->" directly;
1998 . proves theorems immediately and stores them in the theory,
1999 . creates hierachical name space,
2000 . now uses normal mixfix annotations (instead of cinfix...),
2001 . minor changes to some names and values (for consistency),
2002 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
2003 . separator between mutual domain defs: changed "," to "and",
2004 . improved handling of sort constraints; now they have to
2005 appear on the left-hand side of the equations only;
2007 * fixed LAM <x,y,zs>.b syntax;
2009 * added extended adm_tac to simplifier in HOLCF -- can now discharge
2010 adm (%x. P (t x)), where P is chainfinite and t continuous;
2015 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
2016 with `addloop' of the simplifier to faciliate case splitting in premises.
2018 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
2019 in HOL, they strip ALL and --> from proved theorems;
2023 New in Isabelle94-8 (May 1997)
2024 ------------------------------
2026 *** General Changes ***
2028 * new utilities to build / run / maintain Isabelle etc. (in parts
2029 still somewhat experimental); old Makefiles etc. still functional;
2031 * new 'Isabelle System Manual';
2033 * INSTALL text, together with ./configure and ./build scripts;
2035 * reimplemented type inference for greater efficiency, better error
2036 messages and clean internal interface;
2038 * prlim command for dealing with lots of subgoals (an easier way of
2039 setting goals_limit);
2044 * supports alternative (named) syntax tables (parser and pretty
2045 printer); internal interface is provided by add_modesyntax(_i);
2047 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
2048 be used in conjunction with the Isabelle symbol font; uses the
2049 "symbols" syntax table;
2051 * added token_translation interface (may translate name tokens in
2052 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
2053 the current print_mode); IMPORTANT: user print translation functions
2054 are responsible for marking newly introduced bounds
2055 (Syntax.mark_boundT);
2057 * token translations for modes "xterm" and "xterm_color" that display
2058 names in bold, underline etc. or colors (which requires a color
2061 * infixes may now be declared with names independent of their syntax;
2063 * added typed_print_translation (like print_translation, but may
2064 access type of constant);
2067 *** Classical Reasoner ***
2069 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has
2070 some limitations. Blast_tac...
2071 + ignores addss, addbefore, addafter; this restriction is intrinsic
2072 + ignores elimination rules that don't have the correct format
2073 (the conclusion MUST be a formula variable)
2074 + ignores types, which can make HOL proofs fail
2075 + rules must not require higher-order unification, e.g. apply_type in ZF
2076 [message "Function Var's argument not a bound variable" relates to this]
2077 + its proof strategy is more general but can actually be slower
2079 * substitution with equality assumptions no longer permutes other
2082 * minor changes in semantics of addafter (now called addaltern); renamed
2083 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
2084 (and access functions for it);
2086 * improved combination of classical reasoner and simplifier:
2087 + functions for handling clasimpsets
2088 + improvement of addss: now the simplifier is called _after_ the
2090 + safe variant of addss called addSss: uses safe simplifications
2091 _during_ the safe steps. It is more complete as it allows multiple
2092 instantiations of unknowns (e.g. with slow_tac).
2096 * added interface for simplification procedures (functions that
2097 produce *proven* rewrite rules on the fly, depending on current
2100 * ordering on terms as parameter (used for ordered rewriting);
2102 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
2104 * the solver is now split into a safe and an unsafe part.
2105 This should be invisible for the normal user, except that the
2106 functions setsolver and addsolver have been renamed to setSolver and
2107 addSolver; added safe_asm_full_simp_tac;
2112 * a generic induction tactic `induct_tac' which works for all datatypes and
2113 also for type `nat';
2115 * a generic case distinction tactic `exhaust_tac' which works for all
2116 datatypes and also for type `nat';
2118 * each datatype comes with a function `size';
2120 * patterns in case expressions allow tuple patterns as arguments to
2121 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
2123 * primrec now also works with type nat;
2125 * recdef: a new declaration form, allows general recursive functions to be
2126 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
2128 * the constant for negation has been renamed from "not" to "Not" to
2129 harmonize with FOL, ZF, LK, etc.;
2131 * HOL/ex/LFilter theory of a corecursive "filter" functional for
2134 * HOL/Modelcheck demonstrates invocation of model checker oracle;
2136 * HOL/ex/Ring.thy declares cring_simp, which solves equational
2137 problems in commutative rings, using axiomatic type classes for + and *;
2139 * more examples in HOL/MiniML and HOL/Auth;
2141 * more default rewrite rules for quantifiers, union/intersection;
2143 * a new constant `arbitrary == @x.False';
2145 * HOLCF/IOA replaces old HOL/IOA;
2147 * HOLCF changes: derived all rules and arities
2148 + axiomatic type classes instead of classes
2149 + typedef instead of faking type definitions
2150 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
2151 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
2152 + eliminated the types void, one, tr
2153 + use unit lift and bool lift (with translations) instead of one and tr
2154 + eliminated blift from Lift3.thy (use Def instead of blift)
2155 all eliminated rules are derived as theorems --> no visible changes ;
2160 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default
2161 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back
2162 as ZF_cs addSIs [equalityI];
2166 New in Isabelle94-7 (November 96)
2167 ---------------------------------
2169 * allowing negative levels (as offsets) in prlev and choplev;
2171 * super-linear speedup for large simplifications;
2173 * FOL, ZF and HOL now use miniscoping: rewriting pushes
2174 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
2175 FAIL); can suppress it using the command Delsimps (ex_simps @
2176 all_simps); De Morgan laws are also now included, by default;
2178 * improved printing of ==> : ~:
2180 * new object-logic "Sequents" adds linear logic, while replacing LK
2181 and Modal (thanks to Sara Kalvala);
2183 * HOL/Auth: correctness proofs for authentication protocols;
2185 * HOL: new auto_tac combines rewriting and classical reasoning (many
2186 examples on HOL/Auth);
2188 * HOL: new command AddIffs for declaring theorems of the form P=Q to
2189 the rewriter and classical reasoner simultaneously;
2191 * function uresult no longer returns theorems in "standard" format;
2192 regain previous version by: val uresult = standard o uresult;
2199 * oracles -- these establish an interface between Isabelle and trusted
2200 external reasoners, which may deliver results as theorems;
2202 * proof objects (in particular record all uses of oracles);
2204 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
2206 * "constdefs" section in theory files;
2208 * "primrec" section (HOL) no longer requires names;
2210 * internal type "tactic" now simply "thm -> thm Sequence.seq";
2217 * reduced space requirements;
2219 * automatic HTML generation from theories;
2221 * theory files no longer require "..." (quotes) around most types;
2223 * new examples, including two proofs of the Church-Rosser theorem;
2225 * non-curried (1994) version of HOL is no longer distributed;
2232 * greatly reduced space requirements;
2234 * theory files (.thy) no longer require \...\ escapes at line breaks;
2236 * searchable theorem database (see the section "Retrieving theorems" on
2237 page 8 of the Reference Manual);
2239 * new examples, including Grabczewski's monumental case study of the
2242 * The previous version of HOL renamed to Old_HOL;
2244 * The new version of HOL (previously called CHOL) uses a curried syntax
2245 for functions. Application looks like f a b instead of f(a,b);
2247 * Mutually recursive inductive definitions finally work in HOL;
2249 * In ZF, pattern-matching on tuples is now available in all abstractions and
2250 translates to the operator "split";
2257 * new infix operator, addss, allowing the classical reasoner to
2258 perform simplification at each step of its search. Example:
2259 fast_tac (cs addss ss)
2261 * a new logic, CHOL, the same as HOL, but with a curried syntax
2262 for functions. Application looks like f a b instead of f(a,b). Also pairs
2263 look like (a,b) instead of <a,b>;
2265 * PLEASE NOTE: CHOL will eventually replace HOL!
2267 * In CHOL, pattern-matching on tuples is now available in all abstractions.
2268 It translates to the operator "split". A new theory of integers is available;
2270 * In ZF, integer numerals now denote two's-complement binary integers.
2271 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;
2273 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
2274 of the Axiom of Choice;
2281 * Significantly faster resolution;
2283 * the different sections in a .thy file can now be mixed and repeated
2286 * Database of theorems for FOL, HOL and ZF. New
2287 commands including qed, qed_goal and bind_thm store theorems in the database.
2289 * Simple database queries: return a named theorem (get_thm) or all theorems of
2290 a given theory (thms_of), or find out what theory a theorem was proved in
2293 * Bugs fixed in the inductive definition and datatype packages;
2295 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
2296 and HOL_dup_cs obsolete;
2298 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
2301 * Simpler definition of function space in ZF;
2303 * new results about cardinal and ordinal arithmetic in ZF;
2305 * 'subtype' facility in HOL for introducing new types as subsets of existing