1 Isabelle NEWS -- history user-relevant changes
2 ==============================================
4 New in this Isabelle release
5 ----------------------------
9 * Pure: Greek letters (except small lambda, \<lambda>), as well as gothic
10 (\<aa>...\<zz>\<AA>...\<ZZ>), caligraphic (\<A>...\<Z>), and euler
11 (\<a>...\<z>), are now considered normal letters, and can therefore
12 be used anywhere where an ASCII letter (a...zA...Z) has until
13 now. COMPATIBILITY: This obviously changes the parsing of some
14 terms, especially where a symbol has been used as a binder, say
15 '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
16 as an identifier. Fix it by inserting a space around former
17 symbols. Call 'isatool fixgreek' to try to fix parsing errors in
18 existing theory and ML files.
20 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
22 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
23 allowed in identifiers. Similar to greek letters \<^isub> is now considered
24 a normal (but invisible) letter. For multiple letter subscripts repeat
25 \<^isub> like this: x\<^isub>1\<^isub>2.
27 * Pure: Using new Isar command "finalconsts" (or the ML functions
28 Theory.add_finals or Theory.add_finals_i) it is now possible to
29 declare constants "final", which prevents their being given a definition
30 later. It is useful for constants whose behaviour is fixed axiomatically
31 rather than definitionally, such as the meta-logic connectives.
35 * Tactic emulation methods ?rule_tac, cut_tac, subgoal_tac and thin_tac:
36 - Now understand static (Isar) contexts. As a consequence, users of Isar
37 locales are no longer forced to write Isar proof scripts.
38 For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
40 - INCOMPATIBILITY: names of variables to be instantiated may no
41 longer be enclosed in quotes. Instead, precede variable name with `?'.
42 This is consistent with the instantiation attribute "where".
45 - Goal statements involving the context element "includes" no longer
46 generate theorems with internal delta predicates (those ending on
47 "_axioms") in the premise.
48 Resolve particular premise with <locale>.intro to obtain old form.
49 - Fixed bug in type inference ("unify_frozen") that prevented mix of target
50 specification and "includes" elements in goal statement.
51 - Rule sets <locale>.intro and <locale>.axioms no longer declared as
52 [intro?] and [elim?] (respectively) by default.
54 * HOL: Tactic emulation methods induct_tac and case_tac understand static
60 - Record types are now by default printed with their type abbreviation
61 instead of the list of all field types. This can be configured via
62 the reference "print_record_type_abbr".
63 - Simproc "record_upd_simproc" for simplification of multiple updates added
64 (not enabled by default).
65 - Tactic "record_split_simp_tac" to split and simplify records added.
67 * 'specification' command added, allowing for definition by
68 specification. There is also an 'ax_specification' command that
69 introduces the new constants axiomatically.
71 * SET-Protocol: formalization and verification of the SET protocol suite;
73 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
74 defintions, thanks to Sava Krsti\'{c} and John Matthews.
76 New in Isabelle2003 (May 2003)
77 --------------------------------
83 - Completely reimplemented method simp (ML: Asm_full_simp_tac):
84 Assumptions are now subject to complete mutual simplification,
85 not just from left to right. The simplifier now preserves
86 the order of assumptions.
88 Potential INCOMPATIBILITY:
90 -- simp sometimes diverges where the old version did
91 not, e.g. invoking simp on the goal
93 [| P (f x); y = x; f x = f y |] ==> Q
95 now gives rise to the infinite reduction sequence
97 P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
99 Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
102 -- Tactics combining classical reasoner and simplification (such as auto)
103 are also affected by this change, because many of them rely on
104 simp. They may sometimes diverge as well or yield a different numbers
105 of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
106 in case of problems. Sometimes subsequent calls to the classical
107 reasoner will fail because a preceeding call to the simplifier too
108 eagerly simplified the goal, e.g. deleted redundant premises.
110 - The simplifier trace now shows the names of the applied rewrite rules
112 - You can limit the number of recursive invocations of the simplifier
113 during conditional rewriting (where the simplifie tries to solve the
114 conditions before applying the rewrite rule):
115 ML "simp_depth_limit := n"
116 where n is an integer. Thus you can force termination where previously
117 the simplifier would diverge.
119 - Accepts free variables as head terms in congruence rules. Useful in Isar.
121 - No longer aborts on failed congruence proof. Instead, the
122 congruence is ignored.
124 * Pure: New generic framework for extracting programs from constructive
125 proofs. See HOL/Extraction.thy for an example instantiation, as well
126 as HOL/Extraction for some case studies.
128 * Pure: The main goal of the proof state is no longer shown by default, only
129 the subgoals. This behaviour is controlled by a new flag.
130 PG menu: Isabelle/Isar -> Settings -> Show Main Goal
131 (ML: Proof.show_main_goal).
133 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
134 rules whose conclusion matches subgoal 1:
135 PG menu: Isabelle/Isar -> Show me -> matching rules
136 The rules are ordered by how closely they match the subgoal.
137 In particular, rules that solve a subgoal outright are displayed first
138 (or rather last, the way they are printed).
139 (ML: ProofGeneral.print_intros())
141 * Pure: New flag trace_unify_fail causes unification to print
142 diagnostic information (PG: in trace buffer) when it fails. This is
143 useful for figuring out why single step proofs like rule, erule or
146 * Pure: Locale specifications now produce predicate definitions
147 according to the body of text (covering assumptions modulo local
148 definitions); predicate "loc_axioms" covers newly introduced text,
149 while "loc" is cumulative wrt. all included locale expressions; the
150 latter view is presented only on export into the global theory
151 context; potential INCOMPATIBILITY, use "(open)" option to fall back
152 on the old view without predicates;
154 * Pure: predefined locales "var" and "struct" are useful for sharing
155 parameters (as in CASL, for example); just specify something like
156 ``var x + var y + struct M'' as import;
158 * Pure: improved thms_containing: proper indexing of facts instead of
159 raw theorems; check validity of results wrt. current name space;
160 include local facts of proof configuration (also covers active
161 locales), cover fixed variables in index; may use "_" in term
162 specification; an optional limit for the number of printed facts may
163 be given (the default is 40);
165 * Pure: disallow duplicate fact bindings within new-style theory files
168 * Provers: improved induct method: assumptions introduced by case
169 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
170 the goal statement); "foo" still refers to all facts collectively;
172 * Provers: the function blast.overloaded has been removed: all constants
173 are regarded as potentially overloaded, which improves robustness in exchange
174 for slight decrease in efficiency;
176 * Provers/linorder: New generic prover for transitivity reasoning over
177 linear orders. Note: this prover is not efficient!
179 * Isar: preview of problems to finish 'show' now produce an error
180 rather than just a warning (in interactive mode);
187 - Produces a counter example if it cannot prove a goal.
188 Note that the counter example may be spurious if the goal is not a formula
189 of quantifier-free linear arithmetic.
190 In ProofGeneral the counter example appears in the trace buffer.
192 - Knows about div k and mod k where k is a numeral of type nat or int.
194 - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
195 linear arithmetic fails. This takes account of quantifiers and divisibility.
196 Presburger arithmetic can also be called explicitly via presburger(_tac).
198 * simp's arithmetic capabilities have been enhanced a bit: it now
199 takes ~= in premises into account (by performing a case split);
201 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
202 are distributed over a sum of terms;
204 * New tactic "trans_tac" and method "trans" instantiate
205 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
208 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
209 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
211 * 'typedef' command has new option "open" to suppress the set
214 * functions Min and Max on finite sets have been introduced (theory
217 * attribute [symmetric] now works for relations as well; it turns
218 (x,y) : R^-1 into (y,x) : R, and vice versa;
220 * induct over a !!-quantified statement (say !!x1..xn):
221 each "case" automatically performs "fix x1 .. xn" with exactly those names.
223 * Map: `empty' is no longer a constant but a syntactic abbreviation for
224 %x. None. Warning: empty_def now refers to the previously hidden definition
227 * Algebra: formalization of classical algebra. Intended as base for
228 any algebraic development in Isabelle. Currently covers group theory
229 (up to Sylow's theorem) and ring theory (Universal Property of
230 Univariate Polynomials). Contributions welcome;
232 * GroupTheory: deleted, since its material has been moved to Algebra;
234 * Complex: new directory of the complex numbers with numeric constants,
235 nonstandard complex numbers, and some complex analysis, standard and
236 nonstandard (Jacques Fleuriot);
238 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
240 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
243 * Real/HahnBanach: updated and adapted to locales;
245 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
248 * UNITY: added the Meier-Sanders theory of progress sets;
250 * MicroJava: bytecode verifier and lightweight bytecode verifier
251 as abstract algorithms, instantiated to the JVM;
253 * Bali: Java source language formalization. Type system, operational
254 semantics, axiomatic semantics. Supported language features:
255 classes, interfaces, objects,virtual methods, static methods,
256 static/instance fields, arrays, access modifiers, definite
257 assignment, exceptions.
262 * ZF/Constructible: consistency proof for AC (Gödel's constructible
265 * Main ZF: virtually all theories converted to new-style format;
270 * Pure: Tactic.prove provides sane interface for internal proofs;
271 omits the infamous "standard" operation, so this is more appropriate
272 than prove_goalw_cterm in many situations (e.g. in simprocs);
274 * Pure: improved error reporting of simprocs;
276 * Provers: Simplifier.simproc(_i) provides sane interface for setting
280 *** Document preparation ***
282 * uses \par instead of \\ for line breaks in theory text. This may
283 shift some page breaks in large documents. To get the old behaviour
284 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
286 * minimized dependencies of isabelle.sty and isabellesym.sty on
289 * \<euro> now needs package babel/greek instead of marvosym (which
292 * normal size for \<zero>...\<nine> (uses \mathbf instead of
296 New in Isabelle2002 (March 2002)
297 --------------------------------
299 *** Document preparation ***
301 * greatly simplified document preparation setup, including more
302 graceful interpretation of isatool usedir -i/-d/-D options, and more
303 instructive isatool mkdir; users should basically be able to get
304 started with "isatool mkdir HOL Test && isatool make"; alternatively,
305 users may run a separate document processing stage manually like this:
306 "isatool usedir -D output HOL Test && isatool document Test/output";
308 * theory dependency graph may now be incorporated into documents;
309 isatool usedir -g true will produce session_graph.eps/.pdf for use
310 with \includegraphics of LaTeX;
312 * proper spacing of consecutive markup elements, especially text
313 blocks after section headings;
315 * support bold style (for single symbols only), input syntax is like
316 this: "\<^bold>\<alpha>" or "\<^bold>A";
318 * \<bullet> is now output as bold \cdot by default, which looks much
319 better in printed text;
321 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
322 note that these symbols are currently unavailable in Proof General /
323 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
325 * isatool latex no longer depends on changed TEXINPUTS, instead
326 isatool document copies the Isabelle style files to the target
332 * Pure/Provers: improved proof by cases and induction;
333 - 'case' command admits impromptu naming of parameters (such as
335 - 'induct' method divinates rule instantiation from the inductive
336 claim; no longer requires excessive ?P bindings for proper
337 instantiation of cases;
338 - 'induct' method properly enumerates all possibilities of set/type
339 rules; as a consequence facts may be also passed through *type*
340 rules without further ado;
341 - 'induct' method now derives symbolic cases from the *rulified*
342 rule (before it used to rulify cases stemming from the internal
343 atomized version); this means that the context of a non-atomic
344 statement becomes is included in the hypothesis, avoiding the
345 slightly cumbersome show "PROP ?case" form;
346 - 'induct' may now use elim-style induction rules without chaining
347 facts, using ``missing'' premises from the goal state; this allows
348 rules stemming from inductive sets to be applied in unstructured
349 scripts, while still benefitting from proper handling of non-atomic
350 statements; NB: major inductive premises need to be put first, all
351 the rest of the goal is passed through the induction;
352 - 'induct' proper support for mutual induction involving non-atomic
353 rule statements (uses the new concept of simultaneous goals, see
355 - append all possible rule selections, but only use the first
356 success (no backtracking);
357 - removed obsolete "(simplified)" and "(stripped)" options of methods;
358 - undeclared rule case names default to numbers 1, 2, 3, ...;
359 - added 'print_induct_rules' (covered by help item in recent Proof
361 - moved induct/cases attributes to Pure, methods to Provers;
362 - generic method setup instantiated for FOL and HOL;
364 * Pure: support multiple simultaneous goal statements, for example
365 "have a: A and b: B" (same for 'theorem' etc.); being a pure
366 meta-level mechanism, this acts as if several individual goals had
367 been stated separately; in particular common proof methods need to be
368 repeated in order to cover all claims; note that a single elimination
369 step is *not* sufficient to establish the two conjunctions, so this
372 assume "A & B" then have A and B .. (*".." fails*)
374 better use "obtain" in situations as above; alternative refer to
375 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
377 * Pure: proper integration with ``locales''; unlike the original
378 version by Florian Kammüller, Isar locales package high-level proof
379 contexts rather than raw logical ones (e.g. we admit to include
380 attributes everywhere); operations on locales include merge and
381 rename; support for implicit arguments (``structures''); simultaneous
382 type-inference over imports and text; see also HOL/ex/Locales.thy for
385 * Pure: the following commands have been ``localized'', supporting a
386 target locale specification "(in name)": 'lemma', 'theorem',
387 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
388 stored both within the locale and at the theory level (exported and
389 qualified by the locale name);
391 * Pure: theory goals may now be specified in ``long'' form, with
392 ad-hoc contexts consisting of arbitrary locale elements. for example
393 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
394 definitions may be given, too); the result is a meta-level rule with
395 the context elements being discharged in the obvious way;
397 * Pure: new proof command 'using' allows to augment currently used
398 facts after a goal statement ('using' is syntactically analogous to
399 'apply', but acts on the goal's facts only); this allows chained facts
400 to be separated into parts given before and after a claim, as in
401 ``from a and b have C using d and e <proof>'';
403 * Pure: renamed "antecedent" case to "rule_context";
405 * Pure: new 'judgment' command records explicit information about the
406 object-logic embedding (used by several tools internally); no longer
407 use hard-wired "Trueprop";
409 * Pure: added 'corollary' command;
411 * Pure: fixed 'token_translation' command;
413 * Pure: removed obsolete 'exported' attribute;
415 * Pure: dummy pattern "_" in is/let is now automatically lifted over
416 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
417 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
419 * Pure: method 'atomize' presents local goal premises as object-level
420 statements (atomic meta-level propositions); setup controlled via
421 rewrite rules declarations of 'atomize' attribute; example
422 application: 'induct' method with proper rule statements in improper
425 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
426 now consider the syntactic context of assumptions, giving a better
427 chance to get type-inference of the arguments right (this is
428 especially important for locales);
430 * Pure: "sorry" no longer requires quick_and_dirty in interactive
433 * Pure/obtain: the formal conclusion "thesis", being marked as
434 ``internal'', may no longer be reference directly in the text;
435 potential INCOMPATIBILITY, may need to use "?thesis" in rare
438 * Pure: generic 'sym' attribute which declares a rule both as pure
439 'elim?' and for the 'symmetric' operation;
441 * Pure: marginal comments ``--'' may now occur just anywhere in the
442 text; the fixed correlation with particular command syntax has been
445 * Pure: new method 'rules' is particularly well-suited for proof
446 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
447 but often produces more compact proof terms with less detours;
449 * Pure/Provers/classical: simplified integration with pure rule
450 attributes and methods; the classical "intro?/elim?/dest?"
451 declarations coincide with the pure ones; the "rule" method no longer
452 includes classically swapped intros; "intro" and "elim" methods no
453 longer pick rules from the context; also got rid of ML declarations
454 AddXIs/AddXEs/AddXDs; all of this has some potential for
457 * Provers/classical: attribute 'swapped' produces classical inversions
458 of introduction rules;
460 * Provers/simplifier: 'simplified' attribute may refer to explicit
461 rules instead of full simplifier context; 'iff' attribute handles
464 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
466 * HOL: 'recdef' now fails on unfinished automated proofs, use
467 "(permissive)" option to recover old behavior;
469 * HOL: 'inductive' no longer features separate (collective) attributes
470 for 'intros' (was found too confusing);
472 * HOL: properly declared induction rules less_induct and
478 * HOL: moved over to sane numeral syntax; the new policy is as
481 - 0 and 1 are polymorphic constants, which are defined on any
482 numeric type (nat, int, real etc.);
484 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
485 binary representation internally;
487 - type nat has special constructor Suc, and generally prefers Suc 0
488 over 1::nat and Suc (Suc 0) over 2::nat;
490 This change may cause significant problems of INCOMPATIBILITY; here
491 are some hints on converting existing sources:
493 - due to the new "num" token, "-0" and "-1" etc. are now atomic
494 entities, so expressions involving "-" (unary or binary minus) need
495 to be spaced properly;
497 - existing occurrences of "1" may need to be constraint "1::nat" or
498 even replaced by Suc 0; similar for old "2";
500 - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
502 - remove all special provisions on numerals in proofs;
504 * HOL: simp rules nat_number expand numerals on nat to Suc/0
505 representation (depends on bin_arith_simps in the default context);
507 * HOL: symbolic syntax for x^2 (numeral 2);
509 * HOL: the class of all HOL types is now called "type" rather than
510 "term"; INCOMPATIBILITY, need to adapt references to this type class
511 in axclass/classes, instance/arities, and (usually rare) occurrences
512 in typings (of consts etc.); internally the class is called
513 "HOL.type", ML programs should refer to HOLogic.typeS;
515 * HOL/record package improvements:
516 - new derived operations "fields" to build a partial record section,
517 "extend" to promote a fixed record to a record scheme, and
518 "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
519 declared as simp by default;
520 - shared operations ("more", "fields", etc.) now need to be always
521 qualified) --- potential INCOMPATIBILITY;
522 - removed "make_scheme" operations (use "make" with "extend") --
524 - removed "more" class (simply use "term") -- INCOMPATIBILITY;
525 - provides cases/induct rules for use with corresponding Isar
526 methods (for concrete records, record schemes, concrete more
527 parts, and schematic more parts -- in that order);
528 - internal definitions directly based on a light-weight abstract
529 theory of product types over typedef rather than datatype;
531 * HOL: generic code generator for generating executable ML code from
532 specifications; specific support for HOL constructs such as inductive
533 datatypes and sets, as well as recursive functions; can be invoked
534 via 'generate_code' theory section;
536 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
538 * HOL: consolidated and renamed several theories. In particular:
539 Ord.thy has been absorbed into HOL.thy
540 String.thy has been absorbed into List.thy
542 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
543 (beware of argument permutation!);
545 * HOL: linorder_less_split superseded by linorder_cases;
547 * HOL/List: "nodups" renamed to "distinct";
549 * HOL: added "The" definite description operator; move Hilbert's "Eps"
550 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
551 - Ex_def has changed, now need to use some_eq_ex
553 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
554 in this (rare) case use:
556 delSWrapper "split_all_tac"
557 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
559 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
562 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
563 Isabelle's type classes, ^ on functions and relations has too general
564 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
565 necessary to attach explicit type constraints;
567 * HOL/Relation: the prefix name of the infix "O" has been changed from
568 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
569 renamed accordingly (eg "compI" -> "rel_compI").
571 * HOL: syntax translations now work properly with numerals and records
574 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
575 of "lam" -- INCOMPATIBILITY;
577 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
578 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
579 renamed "Product_Type.unit";
581 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
583 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
586 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
589 * HOL/IMP: updated and converted to new-style theory format; several
590 parts turned into readable document, with proper Isar proof texts and
591 some explanations (by Gerwin Klein);
593 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
595 * HOL-Hyperreal is now a logic image;
600 * Isar: consts/constdefs supports mixfix syntax for continuous
603 * Isar: domain package adapted to new-style theory format, e.g. see
606 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
607 potential INCOMPATIBILITY; now use plain induct_tac instead of former
608 lift.induct_tac, always use UU instead of Undef;
610 * HOLCF/IMP: updated and converted to new-style theory;
615 * Isar: proper integration of logic-specific tools and packages,
616 including theory commands '(co)inductive', '(co)datatype',
617 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
618 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
620 * theory Main no longer includes AC; for the Axiom of Choice, base
621 your theory on Main_ZFC;
623 * the integer library now covers quotients and remainders, with many
624 laws relating division to addition, multiplication, etc.;
626 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
627 typeless version of the formalism;
629 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
632 * ZF/Induct: new directory for examples of inductive definitions,
633 including theory Multiset for multiset orderings; converted to
634 new-style theory format;
636 * ZF: many new theorems about lists, ordinals, etc.;
641 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
642 variable proof controls level of detail: 0 = no proofs (only oracle
643 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
644 also ref manual for further ML interfaces;
646 * Pure/axclass: removed obsolete ML interface
647 goal_subclass/goal_arity;
649 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
650 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
651 separate tokens, so expressions involving minus need to be spaced
654 * Pure/syntax: support non-oriented infixes, using keyword "infix"
655 rather than "infixl" or "infixr";
657 * Pure/syntax: concrete syntax for dummy type variables admits genuine
658 sort constraint specifications in type inference; e.g. "x::_::foo"
659 ensures that the type of "x" is of sort "foo" (but not necessarily a
662 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
663 control output of nested => (types); the default behavior is
666 * Pure/syntax: builtin parse translation for "_constify" turns valued
667 tokens into AST constants;
669 * Pure/syntax: prefer later declarations of translations and print
670 translation functions; potential INCOMPATIBILITY: need to reverse
671 multiple declarations for same syntax element constant;
673 * Pure/show_hyps reset by default (in accordance to existing Isar
676 * Provers/classical: renamed addaltern to addafter, addSaltern to
679 * Provers/clasimp: ``iff'' declarations now handle conditional rules
682 * system: tested support for MacOS X; should be able to get Isabelle +
683 Proof General to work in a plain Terminal after installing Poly/ML
684 (e.g. from the Isabelle distribution area) and GNU bash alone
685 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
686 support requires further installations, e.g. from
687 http://fink.sourceforge.net/);
689 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
691 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
692 of 40 MB), cf. ML_OPTIONS;
694 * system: Proof General keywords specification is now part of the
695 Isabelle distribution (see etc/isar-keywords.el);
697 * system: support for persistent Proof General sessions (refrain from
698 outdating all loaded theories on startup); user may create writable
699 logic images like this: ``isabelle -q HOL Test'';
701 * system: smart selection of Isabelle process versus Isabelle
702 interface, accommodates case-insensitive file systems (e.g. HFS+); may
703 run both "isabelle" and "Isabelle" even if file names are badly
704 damaged (executable inspects the case of the first letter of its own
705 name); added separate "isabelle-process" and "isabelle-interface";
707 * system: refrain from any attempt at filtering input streams; no
708 longer support ``8bit'' encoding of old isabelle font, instead proper
709 iso-latin characters may now be used; the related isatools
710 "symbolinput" and "nonascii" have disappeared as well;
712 * system: removed old "xterm" interface (the print modes "xterm" and
713 "xterm_color" are still available for direct use in a suitable
718 New in Isabelle99-2 (February 2001)
719 -----------------------------------
721 *** Overview of INCOMPATIBILITIES ***
723 * HOL: please note that theories in the Library and elsewhere often use the
724 new-style (Isar) format; to refer to their theorems in an ML script you must
725 bind them to ML identifers by e.g. val thm_name = thm "thm_name";
727 * HOL: inductive package no longer splits induction rule aggressively,
728 but only as far as specified by the introductions given; the old
729 format may be recovered via ML function complete_split_rule or attribute
730 'split_rule (complete)';
732 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
733 gfp_Tarski to gfp_unfold;
735 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
737 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
738 relation); infix "^^" has been renamed "``"; infix "``" has been
739 renamed "`"; "univalent" has been renamed "single_valued";
741 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
744 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
746 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
748 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
749 consequence, it is no longer monotonic wrt. the local goal context
750 (which is now passed through the inductive cases);
752 * Document preparation: renamed standard symbols \<ll> to \<lless> and
753 \<gg> to \<ggreater>;
756 *** Document preparation ***
758 * \isabellestyle{NAME} selects version of Isabelle output (currently
759 available: are "it" for near math-mode best-style output, "sl" for
760 slanted text style, and "tt" for plain type-writer; if no
761 \isabellestyle command is given, output is according to slanted
764 * support sub/super scripts (for single symbols only), input syntax is
765 like this: "A\<^sup>*" or "A\<^sup>\<star>";
767 * some more standard symbols; see Appendix A of the system manual for
768 the complete list of symbols defined in isabellesym.sty;
770 * improved isabelle style files; more abstract symbol implementation
771 (should now use \isamath{...} and \isatext{...} in custom symbol
774 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
775 state; Note that presentation of goal states does not conform to
776 actual human-readable proof documents. Please do not include goal
777 states into document output unless you really know what you are doing!
779 * proper indentation of antiquoted output with proportional LaTeX
782 * no_document ML operator temporarily disables LaTeX document
785 * isatool unsymbolize tunes sources for plain ASCII communication;
790 * Pure: Isar now suffers initial goal statements to contain unbound
791 schematic variables (this does not conform to actual readable proof
792 documents, due to unpredictable outcome and non-compositional proof
793 checking); users who know what they are doing may use schematic goals
794 for Prolog-style synthesis of proven results;
796 * Pure: assumption method (an implicit finishing) now handles actual
799 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
800 initial goal, declare "that" only as Pure intro (only for single
801 steps); the "that" rule assumption may now be involved in implicit
802 finishing, thus ".." becomes a feasible for trivial obtains;
804 * Pure: default proof step now includes 'intro_classes'; thus trivial
805 instance proofs may be performed by "..";
807 * Pure: ?thesis / ?this / "..." now work for pure meta-level
810 * Pure: more robust selection of calculational rules;
812 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
813 rule (as well as the assumption rule);
815 * Pure: 'thm_deps' command visualizes dependencies of theorems and
816 lemmas, using the graph browser tool;
818 * Pure: predict failure of "show" in interactive mode;
820 * Pure: 'thms_containing' now takes actual terms as arguments;
822 * HOL: improved method 'induct' --- now handles non-atomic goals
823 (potential INCOMPATIBILITY); tuned error handling;
825 * HOL: cases and induct rules now provide explicit hints about the
826 number of facts to be consumed (0 for "type" and 1 for "set" rules);
827 any remaining facts are inserted into the goal verbatim;
829 * HOL: local contexts (aka cases) may now contain term bindings as
830 well; the 'cases' and 'induct' methods new provide a ?case binding for
831 the result to be shown in each case;
833 * HOL: added 'recdef_tc' command;
835 * isatool convert assists in eliminating legacy ML scripts;
840 * HOL/Library: a collection of generic theories to be used together
841 with main HOL; the theory loader path already includes this directory
842 by default; the following existing theories have been moved here:
843 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
844 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
846 * HOL/Unix: "Some aspects of Unix file-system security", a typical
847 modelling and verification task performed in Isabelle/HOL +
848 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
850 * HOL/Algebra: special summation operator SUM no longer exists, it has
851 been replaced by setsum; infix 'assoc' now has priority 50 (like
852 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
853 'domain', this makes the theory consistent with mathematical
856 * HOL basics: added overloaded operations "inverse" and "divide"
857 (infix "/"), syntax for generic "abs" operation, generic summation
860 * HOL/typedef: simplified package, provide more useful rules (see also
863 * HOL/datatype: induction rule for arbitrarily branching datatypes is
864 now expressed as a proper nested rule (old-style tactic scripts may
865 require atomize_strip_tac to cope with non-atomic premises);
867 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
868 to "split_conv" (old name still available for compatibility);
870 * HOL: improved concrete syntax for strings (e.g. allows translation
871 rules with string literals);
873 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
874 and Fleuriot's mechanization of analysis, including the transcendental
875 functions for the reals;
877 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
882 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
883 "lam" is displayed as TWO lambda-symbols
885 * CTT: theory Main now available, containing everything (that is, Bool
891 * Pure: the Simplifier has been implemented properly as a derived rule
892 outside of the actual kernel (at last!); the overall performance
893 penalty in practical applications is about 50%, while reliability of
894 the Isabelle inference kernel has been greatly improved;
896 * print modes "brackets" and "no_brackets" control output of nested =>
897 (types) and ==> (props); the default behaviour is "brackets";
899 * Provers: fast_tac (and friends) now handle actual object-logic rules
900 as assumptions as well;
902 * system: support Poly/ML 4.0;
904 * system: isatool install handles KDE version 1 or 2;
908 New in Isabelle99-1 (October 2000)
909 ----------------------------------
911 *** Overview of INCOMPATIBILITIES ***
913 * HOL: simplification of natural numbers is much changed; to partly
914 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
915 issue the following ML commands:
917 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
918 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
920 * HOL: simplification no longer dives into case-expressions; this is
921 controlled by "t.weak_case_cong" for each datatype t;
923 * HOL: nat_less_induct renamed to less_induct;
925 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
926 fixsome to patch .thy and .ML sources automatically;
928 select_equality -> some_equality
929 select_eq_Ex -> some_eq_ex
930 selectI2EX -> someI2_ex
933 select1_equality -> some1_equality
934 Eps_sym_eq -> some_sym_eq_trivial
935 Eps_eq -> some_eq_trivial
937 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
939 * HOL: removed obsolete theorem binding expand_if (refer to split_if
942 * HOL: the recursion equations generated by 'recdef' are now called
943 f.simps instead of f.rules;
945 * HOL: qed_spec_mp now also handles bounded ALL as well;
947 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
950 * HOL: the constant for "f``x" is now "image" rather than "op ``";
952 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
954 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
955 product is now "<*>" instead of "Times"; the lexicographic product is
956 now "<*lex*>" instead of "**";
958 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
959 of main HOL, but was unused); better use HOL's datatype package;
961 * HOL: removed "symbols" syntax for constant "override" of theory Map;
962 the old syntax may be recovered as follows:
965 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
966 (infixl "\\<oplus>" 100)
968 * HOL/Real: "rabs" replaced by overloaded "abs" function;
970 * HOL/ML: even fewer consts are declared as global (see theories Ord,
971 Lfp, Gfp, WF); this only affects ML packages that refer to const names
974 * HOL and ZF: syntax for quotienting wrt an equivalence relation
975 changed from A/r to A//r;
977 * ZF: new treatment of arithmetic (nat & int) may break some old
980 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
981 rulify -> rule_format, elimify -> elim_format, ...);
983 * Isar/Provers: intro/elim/dest attributes changed; renamed
984 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
985 should have to change intro!! to intro? only); replaced "delrule" by
988 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
990 * Provers: strengthened force_tac by using new first_best_tac;
992 * LaTeX document preparation: several changes of isabelle.sty (see
996 *** Document preparation ***
998 * formal comments (text blocks etc.) in new-style theories may now
999 contain antiquotations of thm/prop/term/typ/text to be presented
1000 according to latex print mode; concrete syntax is like this:
1001 @{term[show_types] "f(x) = a + x"};
1003 * isatool mkdir provides easy setup of Isabelle session directories,
1004 including proper document sources;
1006 * generated LaTeX sources are now deleted after successful run
1007 (isatool document -c); may retain a copy somewhere else via -D option
1010 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
1011 style files, achieving self-contained LaTeX sources and simplifying
1014 * old-style theories now produce (crude) LaTeX output as well;
1016 * browser info session directories are now self-contained (may be put
1017 on WWW server seperately); improved graphs of nested sessions; removed
1018 graph for 'all sessions';
1020 * several improvements in isabelle style files; \isabellestyle{it}
1021 produces fake math mode output; \isamarkupheader is now \section by
1022 default; see lib/texinputs/isabelle.sty etc.;
1027 * Isar/Pure: local results and corresponding term bindings are now
1028 subject to Hindley-Milner polymorphism (similar to ML); this
1029 accommodates incremental type-inference very nicely;
1031 * Isar/Pure: new derived language element 'obtain' supports
1032 generalized existence reasoning;
1034 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
1035 support accumulation of results, without applying any rules yet;
1036 useful to collect intermediate results without explicit name
1037 references, and for use with transitivity rules with more than 2
1040 * Isar/Pure: scalable support for case-analysis type proofs: new
1041 'case' language element refers to local contexts symbolically, as
1042 produced by certain proof methods; internally, case names are attached
1043 to theorems as "tags";
1045 * Isar/Pure: theory command 'hide' removes declarations from
1046 class/type/const name spaces;
1048 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
1049 indicate potential overloading;
1051 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
1053 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
1054 "{a,b,c}" instead of {a,b,c};
1056 * Isar/Pure now provides its own version of intro/elim/dest
1057 attributes; useful for building new logics, but beware of confusion
1058 with the version in Provers/classical;
1060 * Isar/Pure: the local context of (non-atomic) goals is provided via
1061 case name 'antecedent';
1063 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
1064 to the current context is now done automatically);
1066 * Isar/Pure: theory command 'method_setup' provides a simple interface
1067 for definining proof methods in ML;
1069 * Isar/Provers: intro/elim/dest attributes changed; renamed
1070 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
1071 most cases, one should have to change intro!! to intro? only);
1072 replaced "delrule" by "rule del";
1074 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
1075 'symmetric' attribute (the latter supercedes [RS sym]);
1077 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
1078 method modifier); 'simp' method: 'only:' modifier removes loopers as
1079 well (including splits);
1081 * Isar/Provers: Simplifier and Classical methods now support all kind
1082 of modifiers used in the past, including 'cong', 'iff', etc.
1084 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
1085 of Simplifier and Classical reasoner);
1087 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
1088 now support named cases; major packages (inductive, datatype, primrec,
1089 recdef) support case names and properly name parameters;
1091 * Isar/HOL: new transitivity rules for substitution in inequalities --
1092 monotonicity conditions are extracted to be proven at end of
1095 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
1098 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
1099 split_if split_if_asm; datatype package provides theorems foo.splits =
1100 foo.split foo.split_asm for each datatype;
1102 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
1103 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
1104 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
1105 use "(cases (simplified))" method in proper proof texts);
1107 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
1109 * Isar: names of theorems etc. may be natural numbers as well;
1111 * Isar: 'pr' command: optional arguments for goals_limit and
1112 ProofContext.prems_limit; no longer prints theory contexts, but only
1115 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
1116 additional print modes to be specified; e.g. "pr(latex)" will print
1117 proof state according to the Isabelle LaTeX style;
1119 * Isar: improved support for emulating tactic scripts, including proof
1120 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
1121 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
1122 (for HOL datatypes);
1124 * Isar: simplified (more robust) goal selection of proof methods: 1st
1125 goal, all goals, or explicit goal specifier (tactic emulation); thus
1126 'proof method scripts' have to be in depth-first order;
1128 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
1130 * Isar: removed 'help' command, which hasn't been too helpful anyway;
1131 should instead use individual commands for printing items
1132 (print_commands, print_methods etc.);
1134 * Isar: added 'nothing' --- the empty list of theorems;
1139 * HOL/MicroJava: formalization of a fragment of Java, together with a
1140 corresponding virtual machine and a specification of its bytecode
1141 verifier and a lightweight bytecode verifier, including proofs of
1142 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
1143 Cornelia Pusch (see also the homepage of project Bali at
1144 http://isabelle.in.tum.de/Bali/);
1146 * HOL/Algebra: new theory of rings and univariate polynomials, by
1149 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
1150 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
1153 * HOL/Lattice: fundamental concepts of lattice theory and order
1154 structures, including duals, properties of bounds versus algebraic
1155 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
1156 Theorem for complete lattices etc.; may also serve as a demonstration
1157 for abstract algebraic reasoning using axiomatic type classes, and
1158 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
1160 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
1163 * HOL/IMPP: extension of IMP with local variables and mutually
1164 recursive procedures, by David von Oheimb;
1166 * HOL/Lambda: converted into new-style theory and document;
1168 * HOL/ex/Multiquote: example of multiple nested quotations and
1169 anti-quotations -- basically a generalized version of de-Bruijn
1170 representation; very useful in avoiding lifting of operations;
1172 * HOL/record: added general record equality rule to simpset; fixed
1173 select-update simplification procedure to handle extended records as
1174 well; admit "r" as field name;
1176 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
1177 other numeric types and also as the identity of groups, rings, etc.;
1179 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
1180 Types nat and int belong to this axclass;
1182 * HOL: greatly improved simplification involving numerals of type nat, int, real:
1183 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k
1184 i*j + k + j*#3*i simplifies to #4*(i*j) + k
1185 two terms #m*u and #n*u are replaced by #(m+n)*u
1186 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
1187 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
1188 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
1190 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
1191 powerful prover for predicate logic but knows nothing of clasets; see
1192 ex/mesontest.ML and ex/mesontest2.ML for example applications;
1194 * HOL: new version of "case_tac" subsumes both boolean case split and
1195 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
1196 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
1198 * HOL: simplification no longer dives into case-expressions: only the
1199 selector expression is simplified, but not the remaining arms; to
1200 enable full simplification of case-expressions for datatype t, you may
1201 remove t.weak_case_cong from the simpset, either globally (Delcongs
1202 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
1204 * HOL/recdef: the recursion equations generated by 'recdef' for
1205 function 'f' are now called f.simps instead of f.rules; if all
1206 termination conditions are proved automatically, these simplification
1207 rules are added to the simpset, as in primrec; rules may be named
1208 individually as well, resulting in a separate list of theorems for
1211 * HOL/While is a new theory that provides a while-combinator. It
1212 permits the definition of tail-recursive functions without the
1213 provision of a termination measure. The latter is necessary once the
1214 invariant proof rule for while is applied.
1216 * HOL: new (overloaded) notation for the set of elements below/above
1217 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
1219 * HOL: theorems impI, allI, ballI bound as "strip";
1221 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
1222 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
1223 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
1225 * HOL/Real: "rabs" replaced by overloaded "abs" function;
1227 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
1228 main HOL, but was unused);
1230 * HOL: fewer consts declared as global (e.g. have to refer to
1231 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
1233 * HOL: tuned AST representation of nested pairs, avoiding bogus output
1234 in case of overlap with user translations (e.g. judgements over
1235 tuples); (note that the underlying logical represenation is still
1241 * ZF: simplification automatically cancels common terms in arithmetic
1242 expressions over nat and int;
1244 * ZF: new treatment of nat to minimize type-checking: all operators
1245 coerce their operands to a natural number using the function natify,
1246 making the algebraic laws unconditional;
1248 * ZF: as above, for int: operators coerce their operands to an integer
1249 using the function intify;
1251 * ZF: the integer library now contains many of the usual laws for the
1252 orderings, including $<=, and monotonicity laws for $+ and $*;
1254 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
1257 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
1258 to the simplifier and classical reasoner simultaneously;
1263 * Provers: blast_tac now handles actual object-logic rules as
1264 assumptions; note that auto_tac uses blast_tac internally as well;
1266 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
1267 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
1269 * Provers: delrules now handles destruct rules as well (no longer need
1270 explicit make_elim);
1272 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
1273 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
1274 use instead the strong form,
1275 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
1276 in HOL, FOL and ZF the function cla_make_elim will create such rules
1277 from destruct-rules;
1279 * Provers: Simplifier.easy_setup provides a fast path to basic
1280 Simplifier setup for new object-logics;
1282 * Pure: AST translation rules no longer require constant head on LHS;
1284 * Pure: improved name spaces: ambiguous output is qualified; support
1285 for hiding of names;
1287 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
1288 XSYMBOL_HOME; no longer need to do manual configuration in most
1291 * system: compression of ML heaps images may now be controlled via -c
1292 option of isabelle and isatool usedir (currently only observed by
1295 * system: isatool installfonts may handle X-Symbol fonts as well (very
1296 useful for remote X11);
1298 * system: provide TAGS file for Isabelle sources;
1300 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
1303 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
1304 timing flag supersedes proof_timing and Toplevel.trace;
1306 * ML: new combinators |>> and |>>> for incremental transformations
1307 with secondary results (e.g. certain theory extensions):
1309 * ML: PureThy.add_defs gets additional argument to indicate potential
1310 overloading (usually false);
1312 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
1317 New in Isabelle99 (October 1999)
1318 --------------------------------
1320 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1322 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
1323 are no longer simplified. (This allows the simplifier to unfold recursive
1324 functional programs.) To restore the old behaviour, declare
1326 Delcongs [if_weak_cong];
1328 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
1331 * HOL: the predicate "inj" is now defined by translation to "inj_on";
1333 * HOL/datatype: mutual_induct_tac no longer exists --
1334 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
1336 * HOL/typedef: fixed type inference for representing set; type
1337 arguments now have to occur explicitly on the rhs as type constraints;
1339 * ZF: The con_defs part of an inductive definition may no longer refer
1340 to constants declared in the same theory;
1342 * HOL, ZF: the function mk_cases, generated by the inductive
1343 definition package, has lost an argument. To simplify its result, it
1344 uses the default simpset instead of a supplied list of theorems.
1346 * HOL/List: the constructors of type list are now Nil and Cons;
1348 * Simplifier: the type of the infix ML functions
1349 setSSolver addSSolver setSolver addSolver
1350 is now simpset * solver -> simpset where `solver' is a new abstract type
1351 for packaging solvers. A solver is created via
1352 mk_solver: string -> (thm list -> int -> tactic) -> solver
1353 where the string argument is only a comment.
1358 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
1359 decision procedure for linear arithmetic. Currently it is used for
1360 types `nat', `int', and `real' in HOL (see below); it can, should and
1361 will be instantiated for other types and logics as well.
1363 * The simplifier now accepts rewrite rules with flexible heads, eg
1364 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
1365 They are applied like any rule with a non-pattern lhs, i.e. by first-order
1371 * New Isabelle/Isar subsystem provides an alternative to traditional
1372 tactical theorem proving; together with the ProofGeneral/isar user
1373 interface it offers an interactive environment for developing human
1374 readable proof documents (Isar == Intelligible semi-automated
1375 reasoning); for further information see isatool doc isar-ref,
1376 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
1378 * improved and simplified presentation of theories: better HTML markup
1379 (including colors), graph views in several sizes; isatool usedir now
1380 provides a proper interface for user theories (via -P option); actual
1381 document preparation based on (PDF)LaTeX is available as well (for
1382 new-style theories only); see isatool doc system for more information;
1384 * native support for Proof General, both for classic Isabelle and
1387 * ML function thm_deps visualizes dependencies of theorems and lemmas,
1388 using the graph browser tool;
1390 * Isabelle manuals now also available as PDF;
1392 * theory loader rewritten from scratch (may not be fully
1393 bug-compatible); old loadpath variable has been replaced by show_path,
1394 add_path, del_path, reset_path functions; new operations such as
1395 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
1398 * improved isatool install: option -k creates KDE application icon,
1399 option -p DIR installs standalone binaries;
1401 * added ML_PLATFORM setting (useful for cross-platform installations);
1402 more robust handling of platform specific ML images for SML/NJ;
1404 * the settings environment is now statically scoped, i.e. it is never
1405 created again in sub-processes invoked from isabelle, isatool, or
1408 * path element specification '~~' refers to '$ISABELLE_HOME';
1410 * in locales, the "assumes" and "defines" parts may be omitted if
1413 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
1416 * new print_mode "HTML";
1418 * new flag show_tags controls display of tags of theorems (which are
1419 basically just comments that may be attached by some tools);
1421 * Isamode 2.6 requires patch to accomodate change of Isabelle font
1422 mode and goal output format:
1424 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
1426 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
1428 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
1429 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
1431 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
1433 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
1435 * function bind_thms stores lists of theorems (cf. bind_thm);
1437 * new shorthand tactics ftac, eatac, datac, fatac;
1439 * qed (and friends) now accept "" as result name; in that case the
1440 theorem is not stored, but proper checks and presentation of the
1443 * theorem database now also indexes constants "Trueprop", "all",
1444 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
1449 ** HOL arithmetic **
1451 * There are now decision procedures for linear arithmetic over nat and
1454 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
1455 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
1456 are treated as atomic; subformulae not involving type `nat' or `int'
1457 are ignored; quantified subformulae are ignored unless they are
1458 positive universal or negative existential. The tactic has to be
1459 invoked by hand and can be a little bit slow. In particular, the
1460 running time is exponential in the number of occurrences of `min' and
1461 `max', and `-' on `nat'.
1463 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
1464 (negated) (in)equalities among the premises and the conclusion into
1465 account (i.e. no compound formulae) and does not know about `min' and
1466 `max', and `-' on `nat'. It is fast and is used automatically by the
1469 NB: At the moment, these decision procedures do not cope with mixed
1470 nat/int formulae where the two parts interact, such as `m < n ==>
1473 * HOL/Numeral provides a generic theory of numerals (encoded
1474 efficiently as bit strings); setup for types nat/int/real is in place;
1475 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
1476 int, existing theories and proof scripts may require a few additional
1479 * integer division and remainder can now be performed on constant
1482 * many properties of integer multiplication, division and remainder
1485 * An interface to the Stanford Validity Checker (SVC) is available through the
1486 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic
1487 are proved automatically. SVC must be installed separately, and its results
1488 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
1489 invocation of the underlying oracle). For SVC see
1490 http://verify.stanford.edu/SVC
1492 * IsaMakefile: the HOL-Real target now builds an actual image;
1497 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
1498 (in Isabelle/Isar) -- by Gertrud Bauer;
1500 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
1501 analysis for assembly languages with subtypes;
1503 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
1504 -- avoids syntactic ambiguities and treats state, transition, and
1505 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
1506 changed syntax and (many) tactics;
1508 * HOL/inductive: Now also handles more general introduction rules such
1509 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
1510 theorems are now maintained within the theory (maintained via the
1513 * HOL/datatype: Now also handles arbitrarily branching datatypes
1514 (using function types) such as
1516 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
1518 * HOL/record: record_simproc (part of the default simpset) takes care
1519 of selectors applied to updated records; record_split_tac is no longer
1520 part of the default claset; update_defs may now be removed from the
1521 simpset in many cases; COMPATIBILITY: old behavior achieved by
1523 claset_ref () := claset() addSWrapper record_split_wrapper;
1524 Delsimprocs [record_simproc]
1526 * HOL/typedef: fixed type inference for representing set; type
1527 arguments now have to occur explicitly on the rhs as type constraints;
1529 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
1530 names rather than an ML expression;
1532 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
1533 supplied later. Program schemes can be defined, such as
1534 "While B C s = (if B s then While B C (C s) else s)"
1535 where the well-founded relation can be chosen after B and C have been given.
1537 * HOL/List: the constructors of type list are now Nil and Cons;
1538 INCOMPATIBILITY: while [] and infix # syntax is still there, of
1539 course, ML tools referring to List.list.op # etc. have to be adapted;
1541 * HOL_quantifiers flag superseded by "HOL" print mode, which is
1542 disabled by default; run isabelle with option -m HOL to get back to
1543 the original Gordon/HOL-style output;
1545 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
1546 ALL x<=y. P, EX x<y. P, EX x<=y. P;
1548 * HOL basic syntax simplified (more orthogonal): all variants of
1549 All/Ex now support plain / symbolic / HOL notation; plain syntax for
1550 Eps operator is provided as well: "SOME x. P[x]";
1552 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
1554 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
1555 thus available for user theories;
1557 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
1558 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
1561 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
1562 several times and then mp;
1567 * the notation <<...>> is now available as a notation for sequences of
1570 * the simplifier is now installed
1572 * the axiom system has been generalized (thanks to Soren Heilmann)
1574 * the classical reasoner now has a default rule database
1579 * new primrec section allows primitive recursive functions to be given
1580 directly (as in HOL) over datatypes and the natural numbers;
1582 * new tactics induct_tac and exhaust_tac for induction (or case
1583 analysis) over datatypes and the natural numbers;
1585 * the datatype declaration of type T now defines the recursor T_rec;
1587 * simplification automatically does freeness reasoning for datatype
1590 * automatic type-inference, with AddTCs command to insert new
1591 type-checking rules;
1593 * datatype introduction rules are now added as Safe Introduction rules
1596 * the syntax "if P then x else y" is now available in addition to
1600 *** Internal programming interfaces ***
1602 * tuned simplifier trace output; new flag debug_simp;
1604 * structures Vartab / Termtab (instances of TableFun) offer efficient
1605 tables indexed by indexname_ord / term_ord (compatible with aconv);
1607 * AxClass.axclass_tac lost the theory argument;
1609 * tuned current_goals_markers semantics: begin / end goal avoids
1610 printing empty lines;
1612 * removed prs and prs_fn hook, which was broken because it did not
1613 include \n in its semantics, forcing writeln to add one
1614 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
1615 string -> unit if you really want to output text without newline;
1617 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
1618 plain output, interface builders may have to enable 'isabelle_font'
1619 mode to get Isabelle font glyphs as before;
1621 * refined token_translation interface; INCOMPATIBILITY: output length
1622 now of type real instead of int;
1624 * theory loader actions may be traced via new ThyInfo.add_hook
1625 interface (see src/Pure/Thy/thy_info.ML); example application: keep
1626 your own database of information attached to *whole* theories -- as
1627 opposed to intra-theory data slots offered via TheoryDataFun;
1629 * proper handling of dangling sort hypotheses (at last!);
1630 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
1631 extra sort hypotheses that can be witnessed from the type signature;
1632 the force_strip_shyps flag is gone, any remaining shyps are simply
1633 left in the theorem (with a warning issued by strip_shyps_warning);
1637 New in Isabelle98-1 (October 1998)
1638 ----------------------------------
1640 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1642 * several changes of automated proof tools;
1644 * HOL: major changes to the inductive and datatype packages, including
1645 some minor incompatibilities of theory syntax;
1647 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
1650 * HOL: removed duplicate thms in Arith:
1651 less_imp_add_less should be replaced by trans_less_add1
1652 le_imp_add_le should be replaced by trans_le_add1
1654 * HOL: unary minus is now overloaded (new type constraints may be
1657 * HOL and ZF: unary minus for integers is now #- instead of #~. In
1658 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
1659 now taken as an integer constant.
1661 * Pure: ML function 'theory_of' renamed to 'theory';
1667 1. Asm_full_simp_tac is now more aggressive.
1668 1. It will sometimes reorient premises if that increases their power to
1670 2. It does no longer proceed strictly from left to right but may also
1671 rotate premises to achieve further simplification.
1672 For compatibility reasons there is now Asm_lr_simp_tac which is like the
1673 old Asm_full_simp_tac in that it does not rotate premises.
1674 2. The simplifier now knows a little bit about nat-arithmetic.
1676 * Classical reasoner: wrapper mechanism for the classical reasoner now
1677 allows for selected deletion of wrappers, by introduction of names for
1678 wrapper functionals. This implies that addbefore, addSbefore,
1679 addaltern, and addSaltern now take a pair (name, tactic) as argument,
1680 and that adding two tactics with the same name overwrites the first
1681 one (emitting a warning).
1682 type wrapper = (int -> tactic) -> (int -> tactic)
1683 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
1684 addWrapper, addSWrapper: claset * (string * wrapper) -> claset
1685 delWrapper, delSWrapper: claset * string -> claset
1686 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
1688 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
1689 semantics; addbefore now affects only the unsafe part of step_tac
1690 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
1691 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
1694 * Classical reasoner: setwrapper to setWrapper and compwrapper to
1695 compWrapper; added safe wrapper (and access functions for it);
1697 * HOL/split_all_tac is now much faster and fails if there is nothing
1698 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
1699 and the names of the automatically generated variables have changed.
1700 split_all_tac has moved within claset() from unsafe wrappers to safe
1701 wrappers, which means that !!-bound variables are split much more
1702 aggressively, and safe_tac and clarify_tac now split such variables.
1703 If this splitting is not appropriate, use delSWrapper "split_all_tac".
1704 Note: the same holds for record_split_tac, which does the job of
1705 split_all_tac for record fields.
1707 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
1708 permanently to the default simpset using Addsplits just like
1709 Addsimps. They can be removed via Delsplits just like
1710 Delsimps. Lower-case versions are also available.
1712 * HOL/Simplifier: The rule split_if is now part of the default
1713 simpset. This means that the simplifier will eliminate all occurrences
1714 of if-then-else in the conclusion of a goal. To prevent this, you can
1715 either remove split_if completely from the default simpset by
1716 `Delsplits [split_if]' or remove it in a specific call of the
1717 simplifier using `... delsplits [split_if]'. You can also add/delete
1718 other case splitting rules to/from the default simpset: every datatype
1719 generates suitable rules `split_t_case' and `split_t_case_asm' (where
1720 t is the name of the datatype).
1722 * Classical reasoner / Simplifier combination: new force_tac (and
1723 derivatives Force_tac, force) combines rewriting and classical
1724 reasoning (and whatever other tools) similarly to auto_tac, but is
1725 aimed to solve the given subgoal completely.
1730 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
1731 and `goalw': the theory is no longer needed as an explicit argument -
1732 the current theory context is used; assumptions are no longer returned
1733 at the ML-level unless one of them starts with ==> or !!; it is
1734 recommended to convert to these new commands using isatool fixgoal
1735 (backup your sources first!);
1737 * new top-level commands 'thm' and 'thms' for retrieving theorems from
1738 the current theory context, and 'theory' to lookup stored theories;
1740 * new theory section 'locale' for declaring constants, assumptions and
1741 definitions that have local scope;
1743 * new theory section 'nonterminals' for purely syntactic types;
1745 * new theory section 'setup' for generic ML setup functions
1746 (e.g. package initialization);
1748 * the distribution now includes Isabelle icons: see
1749 lib/logo/isabelle-{small,tiny}.xpm;
1751 * isatool install - install binaries with absolute references to
1754 * isatool logo -- create instances of the Isabelle logo (as EPS);
1756 * print mode 'emacs' reserved for Isamode;
1758 * support multiple print (ast) translations per constant name;
1760 * theorems involving oracles are now printed with a suffixed [!];
1765 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
1767 * HOL/inductive package reorganized and improved: now supports mutual
1773 oddI "n : EVEN ==> Suc n : ODD"
1774 evenI "n : ODD ==> Suc n : EVEN"
1776 new theorem list "elims" contains an elimination rule for each of the
1777 recursive sets; inductive definitions now handle disjunctive premises
1778 correctly (also ZF);
1780 INCOMPATIBILITIES: requires Inductive as an ancestor; component
1781 "mutual_induct" no longer exists - the induction rule is always
1782 contained in "induct";
1785 * HOL/datatype package re-implemented and greatly improved: now
1786 supports mutually recursive datatypes such as
1789 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
1790 | SUM ('a aexp) ('a aexp)
1791 | DIFF ('a aexp) ('a aexp)
1794 'a bexp = LESS ('a aexp) ('a aexp)
1795 | AND ('a bexp) ('a bexp)
1796 | OR ('a bexp) ('a bexp)
1798 as well as indirectly recursive datatypes such as
1801 ('a, 'b) term = Var 'a
1802 | App 'b ((('a, 'b) term) list)
1804 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs
1805 induction on mutually / indirectly recursive datatypes.
1807 Primrec equations are now stored in theory and can be accessed via
1808 <function_name>.simps.
1812 - Theories using datatypes must now have theory Datatype as an
1814 - The specific <typename>.induct_tac no longer exists - use the
1815 generic induct_tac instead.
1816 - natE has been renamed to nat.exhaust - use exhaust_tac
1817 instead of res_inst_tac ... natE. Note that the variable
1818 names in nat.exhaust differ from the names in natE, this
1819 may cause some "fragile" proofs to fail.
1820 - The theorems split_<typename>_case and split_<typename>_case_asm
1821 have been renamed to <typename>.split and <typename>.split_asm.
1822 - Since default sorts of type variables are now handled correctly,
1823 some datatype definitions may have to be annotated with explicit
1825 - Primrec definitions no longer require function name and type
1826 of recursive argument.
1828 Consider using isatool fixdatatype to adapt your theories and proof
1829 scripts to the new package (backup your sources first!).
1832 * HOL/record package: considerably improved implementation; now
1833 includes concrete syntax for record types, terms, updates; theorems
1834 for surjective pairing and splitting !!-bound record variables; proof
1835 support is as follows:
1837 1) standard conversions (selectors or updates applied to record
1838 constructor terms) are part of the standard simpset;
1840 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
1841 made part of standard simpset and claset via addIffs;
1843 3) a tactic for record field splitting (record_split_tac) is part of
1844 the standard claset (addSWrapper);
1846 To get a better idea about these rules you may retrieve them via
1847 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
1848 the name of your record type.
1850 The split tactic 3) conceptually simplifies by the following rule:
1852 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
1854 Thus any record variable that is bound by meta-all will automatically
1855 blow up into some record constructor term, consequently the
1856 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall
1857 solve record problems automatically.
1860 * reorganized the main HOL image: HOL/Integ and String loaded by
1861 default; theory Main includes everything;
1863 * automatic simplification of integer sums and comparisons, using cancellation;
1865 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
1867 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
1869 * many new identities for unions, intersections, set difference, etc.;
1871 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
1872 called split_if, split_split, split_sum_case and split_nat_case (to go
1873 with add/delsplits);
1875 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
1876 (?x::unit) = (); this is made part of the default simpset, which COULD
1877 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
1878 'Delsimprocs [unit_eq_proc];' as last resort); also note that
1879 unit_abs_eta_conv is added in order to counter the effect of
1880 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
1883 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
1886 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1887 It and 'sym RS equals0D' are now in the default claset, giving automatic
1888 disjointness reasoning but breaking a few old proofs.
1890 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
1891 to 'converse' from 'inverse' (for compatibility with ZF and some
1894 * HOL/recdef can now declare non-recursive functions, with {} supplied as
1895 the well-founded relation;
1897 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
1898 Compl A. The "Compl" syntax remains available as input syntax for this
1901 * HOL/Update: new theory of function updates:
1902 f(a:=b) == %x. if x=a then b else f x
1903 may also be iterated as in f(a:=b,c:=d,...);
1905 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
1908 - new function list_update written xs[i:=v] that updates the i-th
1909 list position. May also be iterated as in xs[i:=a,j:=b,...].
1910 - new function `upt' written [i..j(] which generates the list
1911 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
1912 bound write [i..j], which is a shorthand for [i..j+1(].
1913 - new lexicographic orderings and corresponding wellfoundedness theorems.
1916 - removed 'pred' (predecessor) function;
1917 - generalized some theorems about n-1;
1918 - many new laws about "div" and "mod";
1919 - new laws about greatest common divisors (see theory ex/Primes);
1921 * HOL/Relation: renamed the relational operator r^-1 "converse"
1922 instead of "inverse";
1924 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
1925 of the multiset ordering;
1927 * directory HOL/Real: a construction of the reals using Dedekind cuts
1928 (not included by default);
1930 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
1932 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
1933 programs, i.e. different program variables may have different types.
1935 * calling (stac rew i) now fails if "rew" has no effect on the goal
1936 [previously, this check worked only if the rewrite rule was unconditional]
1937 Now rew can involve either definitions or equalities (either == or =).
1942 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
1943 only the theorems proved on ZF.ML;
1945 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1946 It and 'sym RS equals0D' are now in the default claset, giving automatic
1947 disjointness reasoning but breaking a few old proofs.
1949 * ZF/Update: new theory of function updates
1950 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)
1951 may also be iterated as in f(a:=b,c:=d,...);
1953 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.
1955 * calling (stac rew i) now fails if "rew" has no effect on the goal
1956 [previously, this check worked only if the rewrite rule was unconditional]
1957 Now rew can involve either definitions or equalities (either == or =).
1959 * case_tac provided for compatibility with HOL
1960 (like the old excluded_middle_tac, but with subgoals swapped)
1963 *** Internal programming interfaces ***
1965 * Pure: several new basic modules made available for general use, see
1966 also src/Pure/README;
1968 * improved the theory data mechanism to support encapsulation (data
1969 kind name replaced by private Object.kind, acting as authorization
1970 key); new type-safe user interface via functor TheoryDataFun; generic
1971 print_data function becomes basically useless;
1973 * removed global_names compatibility flag -- all theory declarations
1974 are qualified by default;
1976 * module Pure/Syntax now offers quote / antiquote translation
1977 functions (useful for Hoare logic etc. with implicit dependencies);
1978 see HOL/ex/Antiquote for an example use;
1980 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
1983 * new tactical CHANGED_GOAL for checking that a tactic modifies a
1986 * Display.print_goals function moved to Locale.print_goals;
1988 * standard print function for goals supports current_goals_markers
1989 variable for marking begin of proof, end of proof, start of goal; the
1990 default is ("", "", ""); setting current_goals_markers := ("<proof>",
1991 "</proof>", "<goal>") causes SGML like tagged proof state printing,
1996 New in Isabelle98 (January 1998)
1997 --------------------------------
1999 *** Overview of INCOMPATIBILITIES (see below for more details) ***
2001 * changed lexical syntax of terms / types: dots made part of long
2002 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
2004 * simpset (and claset) reference variable replaced by functions
2005 simpset / simpset_ref;
2007 * no longer supports theory aliases (via merge) and non-trivial
2008 implicit merge of thms' signatures;
2010 * most internal names of constants changed due to qualified names;
2012 * changed Pure/Sequence interface (see Pure/seq.ML);
2015 *** General Changes ***
2017 * hierachically structured name spaces (for consts, types, axms, thms
2018 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
2019 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
2020 isatool fixdots ensures space after dots (e.g. "%x. x"); set
2021 long_names for fully qualified output names; NOTE: ML programs
2022 (special tactics, packages etc.) referring to internal names may have
2023 to be adapted to cope with fully qualified names; in case of severe
2024 backward campatibility problems try setting 'global_names' at compile
2025 time to have enrything declared within a flat name space; one may also
2026 fine tune name declarations in theories via the 'global' and 'local'
2029 * reimplemented the implicit simpset and claset using the new anytype
2030 data filed in signatures; references simpset:simpset ref etc. are
2031 replaced by functions simpset:unit->simpset and
2032 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
2033 to patch your ML files accordingly;
2035 * HTML output now includes theory graph data for display with Java
2036 applet or isatool browser; data generated automatically via isatool
2037 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
2039 * defs may now be conditional; improved rewrite_goals_tac to handle
2040 conditional equations;
2042 * defs now admits additional type arguments, using TYPE('a) syntax;
2044 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
2045 creates a new theory node; implicit merge of thms' signatures is
2046 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
2047 transfer:theory->thm->thm in (rare) cases;
2049 * improved handling of draft signatures / theories; draft thms (and
2050 ctyps, cterms) are automatically promoted to real ones;
2052 * slightly changed interfaces for oracles: admit many per theory, named
2053 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
2055 * print_goals: optional output of const types (set show_consts and
2058 * improved output of warnings (###) and errors (***);
2060 * subgoal_tac displays a warning if the new subgoal has type variables;
2062 * removed old README and Makefiles;
2064 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
2066 * removed obsolete init_pps and init_database;
2068 * deleted the obsolete tactical STATE, which was declared by
2069 fun STATE tacfun st = tacfun st st;
2071 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
2072 (which abbreviates $HOME);
2074 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
2075 use isatool fixseq to adapt your ML programs (this works for fully
2076 qualified references to the Sequence structure only!);
2078 * use_thy no longer requires writable current directory; it always
2079 reloads .ML *and* .thy file, if either one is out of date;
2082 *** Classical Reasoner ***
2084 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
2085 tactics that use classical reasoning to simplify a subgoal without
2086 splitting it into several subgoals;
2088 * Safe_tac: like safe_tac but uses the default claset;
2093 * added simplification meta rules:
2094 (asm_)(full_)simplify: simpset -> thm -> thm;
2096 * simplifier.ML no longer part of Pure -- has to be loaded by object
2099 * added prems argument to simplification procedures;
2101 * HOL, FOL, ZF: added infix function `addsplits':
2102 instead of `<simpset> setloop (split_tac <thms>)'
2103 you can simply write `<simpset> addsplits <thms>'
2108 * TYPE('a) syntax for type reflection terms;
2110 * no longer handles consts with name "" -- declare as 'syntax' instead;
2112 * pretty printer: changed order of mixfix annotation preference (again!);
2114 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
2119 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
2120 with `addloop' of the simplifier to faciliate case splitting in premises.
2122 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
2124 * HOL/Auth: new protocol proofs including some for the Internet
2127 * HOL/Map: new theory of `maps' a la VDM;
2129 * HOL/simplifier: simplification procedures nat_cancel_sums for
2130 cancelling out common nat summands from =, <, <= (in)equalities, or
2131 differences; simplification procedures nat_cancel_factor for
2132 cancelling common factor from =, <, <= (in)equalities over natural
2133 sums; nat_cancel contains both kinds of procedures, it is installed by
2134 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
2136 * HOL/simplifier: terms of the form
2137 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)
2139 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
2140 and those of the form
2141 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)
2143 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
2146 Each datatype `t' now comes with a theorem `split_t_case' of the form
2148 P(t_case f1 ... fn x) =
2149 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
2151 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
2154 and a theorem `split_t_case_asm' of the form
2156 P(t_case f1 ... fn x) =
2157 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
2159 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
2161 which can be added to a simpset via `addsplits'. The existing theorems
2162 expand_list_case and expand_option_case have been renamed to
2163 split_list_case and split_option_case.
2166 - `pred n' is automatically converted to `n-1'.
2167 Users are strongly encouraged not to use `pred' any longer,
2168 because it will disappear altogether at some point.
2169 - Users are strongly encouraged to write "0 < n" rather than
2170 "n ~= 0". Theorems and proof tools have been modified towards this
2174 the function "set_of_list" has been renamed "set" (and its theorems too);
2175 the function "nth" now takes its arguments in the reverse order and
2176 has acquired the infix notation "!" as in "xs!n".
2178 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
2180 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
2181 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);
2183 * HOL/record: extensible records with schematic structural subtyping
2184 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
2185 still lacks various theorems and concrete record syntax;
2190 * removed "axioms" and "generated by" sections;
2192 * replaced "ops" section by extended "consts" section, which is capable of
2193 handling the continuous function space "->" directly;
2196 . proves theorems immediately and stores them in the theory,
2197 . creates hierachical name space,
2198 . now uses normal mixfix annotations (instead of cinfix...),
2199 . minor changes to some names and values (for consistency),
2200 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
2201 . separator between mutual domain defs: changed "," to "and",
2202 . improved handling of sort constraints; now they have to
2203 appear on the left-hand side of the equations only;
2205 * fixed LAM <x,y,zs>.b syntax;
2207 * added extended adm_tac to simplifier in HOLCF -- can now discharge
2208 adm (%x. P (t x)), where P is chainfinite and t continuous;
2213 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
2214 with `addloop' of the simplifier to faciliate case splitting in premises.
2216 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
2217 in HOL, they strip ALL and --> from proved theorems;
2221 New in Isabelle94-8 (May 1997)
2222 ------------------------------
2224 *** General Changes ***
2226 * new utilities to build / run / maintain Isabelle etc. (in parts
2227 still somewhat experimental); old Makefiles etc. still functional;
2229 * new 'Isabelle System Manual';
2231 * INSTALL text, together with ./configure and ./build scripts;
2233 * reimplemented type inference for greater efficiency, better error
2234 messages and clean internal interface;
2236 * prlim command for dealing with lots of subgoals (an easier way of
2237 setting goals_limit);
2242 * supports alternative (named) syntax tables (parser and pretty
2243 printer); internal interface is provided by add_modesyntax(_i);
2245 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
2246 be used in conjunction with the Isabelle symbol font; uses the
2247 "symbols" syntax table;
2249 * added token_translation interface (may translate name tokens in
2250 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
2251 the current print_mode); IMPORTANT: user print translation functions
2252 are responsible for marking newly introduced bounds
2253 (Syntax.mark_boundT);
2255 * token translations for modes "xterm" and "xterm_color" that display
2256 names in bold, underline etc. or colors (which requires a color
2259 * infixes may now be declared with names independent of their syntax;
2261 * added typed_print_translation (like print_translation, but may
2262 access type of constant);
2265 *** Classical Reasoner ***
2267 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has
2268 some limitations. Blast_tac...
2269 + ignores addss, addbefore, addafter; this restriction is intrinsic
2270 + ignores elimination rules that don't have the correct format
2271 (the conclusion MUST be a formula variable)
2272 + ignores types, which can make HOL proofs fail
2273 + rules must not require higher-order unification, e.g. apply_type in ZF
2274 [message "Function Var's argument not a bound variable" relates to this]
2275 + its proof strategy is more general but can actually be slower
2277 * substitution with equality assumptions no longer permutes other
2280 * minor changes in semantics of addafter (now called addaltern); renamed
2281 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
2282 (and access functions for it);
2284 * improved combination of classical reasoner and simplifier:
2285 + functions for handling clasimpsets
2286 + improvement of addss: now the simplifier is called _after_ the
2288 + safe variant of addss called addSss: uses safe simplifications
2289 _during_ the safe steps. It is more complete as it allows multiple
2290 instantiations of unknowns (e.g. with slow_tac).
2294 * added interface for simplification procedures (functions that
2295 produce *proven* rewrite rules on the fly, depending on current
2298 * ordering on terms as parameter (used for ordered rewriting);
2300 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
2302 * the solver is now split into a safe and an unsafe part.
2303 This should be invisible for the normal user, except that the
2304 functions setsolver and addsolver have been renamed to setSolver and
2305 addSolver; added safe_asm_full_simp_tac;
2310 * a generic induction tactic `induct_tac' which works for all datatypes and
2311 also for type `nat';
2313 * a generic case distinction tactic `exhaust_tac' which works for all
2314 datatypes and also for type `nat';
2316 * each datatype comes with a function `size';
2318 * patterns in case expressions allow tuple patterns as arguments to
2319 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
2321 * primrec now also works with type nat;
2323 * recdef: a new declaration form, allows general recursive functions to be
2324 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
2326 * the constant for negation has been renamed from "not" to "Not" to
2327 harmonize with FOL, ZF, LK, etc.;
2329 * HOL/ex/LFilter theory of a corecursive "filter" functional for
2332 * HOL/Modelcheck demonstrates invocation of model checker oracle;
2334 * HOL/ex/Ring.thy declares cring_simp, which solves equational
2335 problems in commutative rings, using axiomatic type classes for + and *;
2337 * more examples in HOL/MiniML and HOL/Auth;
2339 * more default rewrite rules for quantifiers, union/intersection;
2341 * a new constant `arbitrary == @x.False';
2343 * HOLCF/IOA replaces old HOL/IOA;
2345 * HOLCF changes: derived all rules and arities
2346 + axiomatic type classes instead of classes
2347 + typedef instead of faking type definitions
2348 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
2349 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
2350 + eliminated the types void, one, tr
2351 + use unit lift and bool lift (with translations) instead of one and tr
2352 + eliminated blift from Lift3.thy (use Def instead of blift)
2353 all eliminated rules are derived as theorems --> no visible changes ;
2358 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default
2359 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back
2360 as ZF_cs addSIs [equalityI];
2364 New in Isabelle94-7 (November 96)
2365 ---------------------------------
2367 * allowing negative levels (as offsets) in prlev and choplev;
2369 * super-linear speedup for large simplifications;
2371 * FOL, ZF and HOL now use miniscoping: rewriting pushes
2372 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
2373 FAIL); can suppress it using the command Delsimps (ex_simps @
2374 all_simps); De Morgan laws are also now included, by default;
2376 * improved printing of ==> : ~:
2378 * new object-logic "Sequents" adds linear logic, while replacing LK
2379 and Modal (thanks to Sara Kalvala);
2381 * HOL/Auth: correctness proofs for authentication protocols;
2383 * HOL: new auto_tac combines rewriting and classical reasoning (many
2384 examples on HOL/Auth);
2386 * HOL: new command AddIffs for declaring theorems of the form P=Q to
2387 the rewriter and classical reasoner simultaneously;
2389 * function uresult no longer returns theorems in "standard" format;
2390 regain previous version by: val uresult = standard o uresult;
2397 * oracles -- these establish an interface between Isabelle and trusted
2398 external reasoners, which may deliver results as theorems;
2400 * proof objects (in particular record all uses of oracles);
2402 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
2404 * "constdefs" section in theory files;
2406 * "primrec" section (HOL) no longer requires names;
2408 * internal type "tactic" now simply "thm -> thm Sequence.seq";
2415 * reduced space requirements;
2417 * automatic HTML generation from theories;
2419 * theory files no longer require "..." (quotes) around most types;
2421 * new examples, including two proofs of the Church-Rosser theorem;
2423 * non-curried (1994) version of HOL is no longer distributed;
2430 * greatly reduced space requirements;
2432 * theory files (.thy) no longer require \...\ escapes at line breaks;
2434 * searchable theorem database (see the section "Retrieving theorems" on
2435 page 8 of the Reference Manual);
2437 * new examples, including Grabczewski's monumental case study of the
2440 * The previous version of HOL renamed to Old_HOL;
2442 * The new version of HOL (previously called CHOL) uses a curried syntax
2443 for functions. Application looks like f a b instead of f(a,b);
2445 * Mutually recursive inductive definitions finally work in HOL;
2447 * In ZF, pattern-matching on tuples is now available in all abstractions and
2448 translates to the operator "split";
2455 * new infix operator, addss, allowing the classical reasoner to
2456 perform simplification at each step of its search. Example:
2457 fast_tac (cs addss ss)
2459 * a new logic, CHOL, the same as HOL, but with a curried syntax
2460 for functions. Application looks like f a b instead of f(a,b). Also pairs
2461 look like (a,b) instead of <a,b>;
2463 * PLEASE NOTE: CHOL will eventually replace HOL!
2465 * In CHOL, pattern-matching on tuples is now available in all abstractions.
2466 It translates to the operator "split". A new theory of integers is available;
2468 * In ZF, integer numerals now denote two's-complement binary integers.
2469 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;
2471 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
2472 of the Axiom of Choice;
2479 * Significantly faster resolution;
2481 * the different sections in a .thy file can now be mixed and repeated
2484 * Database of theorems for FOL, HOL and ZF. New
2485 commands including qed, qed_goal and bind_thm store theorems in the database.
2487 * Simple database queries: return a named theorem (get_thm) or all theorems of
2488 a given theory (thms_of), or find out what theory a theorem was proved in
2491 * Bugs fixed in the inductive definition and datatype packages;
2493 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
2494 and HOL_dup_cs obsolete;
2496 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
2499 * Simpler definition of function space in ZF;
2501 * new results about cardinal and ordinal arithmetic in ZF;
2503 * 'subtype' facility in HOL for introducing new types as subsets of existing