Streamlined it a bit more.
2 Isabelle NEWS -- history user-relevant changes
3 ==============================================
5 New in this Isabelle version
6 ----------------------------
8 *** Overview of INCOMPATIBILITIES (see below for more details) ***
10 * HOL: the constant for f``x is now "image" rather than "op ``".
15 * Algebra: new theory of rings and univariate polynomials, by Clemens Ballarin
19 New in Isabelle99 (October 1999)
20 --------------------------------
22 *** Overview of INCOMPATIBILITIES (see below for more details) ***
24 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
25 are no longer simplified. (This allows the simplifier to unfold recursive
26 functional programs.) To restore the old behaviour, declare
28 Delcongs [if_weak_cong];
30 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
33 * HOL: the predicate "inj" is now defined by translation to "inj_on";
35 * HOL/datatype: mutual_induct_tac no longer exists --
36 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
38 * HOL/typedef: fixed type inference for representing set; type
39 arguments now have to occur explicitly on the rhs as type constraints;
41 * ZF: The con_defs part of an inductive definition may no longer refer
42 to constants declared in the same theory;
44 * HOL, ZF: the function mk_cases, generated by the inductive
45 definition package, has lost an argument. To simplify its result, it
46 uses the default simpset instead of a supplied list of theorems.
48 * HOL/List: the constructors of type list are now Nil and Cons;
50 * Simplifier: the type of the infix ML functions
51 setSSolver addSSolver setSolver addSolver
52 is now simpset * solver -> simpset where `solver' is a new abstract type
53 for packaging solvers. A solver is created via
54 mk_solver: string -> (thm list -> int -> tactic) -> solver
55 where the string argument is only a comment.
60 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
61 decision procedure for linear arithmetic. Currently it is used for
62 types `nat', `int', and `real' in HOL (see below); it can, should and
63 will be instantiated for other types and logics as well.
65 * The simplifier now accepts rewrite rules with flexible heads, eg
66 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
67 They are applied like any rule with a non-pattern lhs, i.e. by first-order
73 * New Isabelle/Isar subsystem provides an alternative to traditional
74 tactical theorem proving; together with the ProofGeneral/isar user
75 interface it offers an interactive environment for developing human
76 readable proof documents (Isar == Intelligible semi-automated
77 reasoning); for further information see isatool doc isar-ref,
78 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
80 * improved presentation of theories: better HTML markup (including
81 colors), graph views in several sizes; isatool usedir now provides a
82 proper interface for user theories (via -P option); actual document
83 preparation based on (PDF)LaTeX is available as well (for new-style
84 theories only); see isatool doc system for more information;
86 * native support for Proof General, both for classic Isabelle and
89 * ML function thm_deps visualizes dependencies of theorems and lemmas,
90 using the graph browser tool;
92 * Isabelle manuals now also available as PDF;
94 * theory loader rewritten from scratch (may not be fully
95 bug-compatible); old loadpath variable has been replaced by show_path,
96 add_path, del_path, reset_path functions; new operations such as
97 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
100 * improved isatool install: option -k creates KDE application icon,
101 option -p DIR installs standalone binaries;
103 * added ML_PLATFORM setting (useful for cross-platform installations);
104 more robust handling of platform specific ML images for SML/NJ;
106 * the settings environment is now statically scoped, i.e. it is never
107 created again in sub-processes invoked from isabelle, isatool, or
110 * path element specification '~~' refers to '$ISABELLE_HOME';
112 * in locales, the "assumes" and "defines" parts may be omitted if
115 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
118 * new print_mode "HTML";
120 * new flag show_tags controls display of tags of theorems (which are
121 basically just comments that may be attached by some tools);
123 * Isamode 2.6 requires patch to accomodate change of Isabelle font
124 mode and goal output format:
126 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
128 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
130 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
131 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
133 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
135 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
137 * function bind_thms stores lists of theorems (cf. bind_thm);
139 * new shorthand tactics ftac, eatac, datac, fatac;
141 * qed (and friends) now accept "" as result name; in that case the
142 theorem is not stored, but proper checks and presentation of the
145 * theorem database now also indexes constants "Trueprop", "all",
146 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
153 * There are now decision procedures for linear arithmetic over nat and
156 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
157 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
158 are treated as atomic; subformulae not involving type `nat' or `int'
159 are ignored; quantified subformulae are ignored unless they are
160 positive universal or negative existential. The tactic has to be
161 invoked by hand and can be a little bit slow. In particular, the
162 running time is exponential in the number of occurrences of `min' and
163 `max', and `-' on `nat'.
165 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
166 (negated) (in)equalities among the premises and the conclusion into
167 account (i.e. no compound formulae) and does not know about `min' and
168 `max', and `-' on `nat'. It is fast and is used automatically by the
171 NB: At the moment, these decision procedures do not cope with mixed
172 nat/int formulae where the two parts interact, such as `m < n ==>
175 * HOL/Numeral provides a generic theory of numerals (encoded
176 efficiently as bit strings); setup for types nat/int/real is in place;
177 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
178 int, existing theories and proof scripts may require a few additional
181 * integer division and remainder can now be performed on constant
184 * many properties of integer multiplication, division and remainder
187 * An interface to the Stanford Validity Checker (SVC) is available through the
188 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic
189 are proved automatically. SVC must be installed separately, and its results
190 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
191 invocation of the underlying oracle). For SVC see
192 http://verify.stanford.edu/SVC
194 * IsaMakefile: the HOL-Real target now builds an actual image;
199 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
200 (in Isabelle/Isar) -- by Gertrud Bauer;
202 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
203 analysis for assembly languages with subtypes;
205 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
206 -- avoids syntactic ambiguities and treats state, transition, and
207 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
208 changed syntax and (many) tactics;
210 * HOL/inductive: Now also handles more general introduction rules such
211 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
212 theorems are now maintained within the theory (maintained via the
215 * HOL/datatype: Now also handles arbitrarily branching datatypes
216 (using function types) such as
218 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
220 * HOL/record: record_simproc (part of the default simpset) takes care
221 of selectors applied to updated records; record_split_tac is no longer
222 part of the default claset; update_defs may now be removed from the
223 simpset in many cases; COMPATIBILITY: old behavior achieved by
225 claset_ref () := claset() addSWrapper record_split_wrapper;
226 Delsimprocs [record_simproc]
228 * HOL/typedef: fixed type inference for representing set; type
229 arguments now have to occur explicitly on the rhs as type constraints;
231 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
232 names rather than an ML expression;
234 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
235 supplied later. Program schemes can be defined, such as
236 "While B C s = (if B s then While B C (C s) else s)"
237 where the well-founded relation can be chosen after B and C have been given.
239 * HOL/List: the constructors of type list are now Nil and Cons;
240 INCOMPATIBILITY: while [] and infix # syntax is still there, of
241 course, ML tools referring to List.list.op # etc. have to be adapted;
243 * HOL_quantifiers flag superseded by "HOL" print mode, which is
244 disabled by default; run isabelle with option -m HOL to get back to
245 the original Gordon/HOL-style output;
247 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
248 ALL x<=y. P, EX x<y. P, EX x<=y. P;
250 * HOL basic syntax simplified (more orthogonal): all variants of
251 All/Ex now support plain / symbolic / HOL notation; plain syntax for
252 Eps operator is provided as well: "SOME x. P[x]";
254 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
256 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
257 thus available for user theories;
259 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
260 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
263 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
264 several times and then mp;
269 * the notation <<...>> is now available as a notation for sequences of
272 * the simplifier is now installed
274 * the axiom system has been generalized (thanks to Soren Heilmann)
276 * the classical reasoner now has a default rule database
281 * new primrec section allows primitive recursive functions to be given
282 directly (as in HOL) over datatypes and the natural numbers;
284 * new tactics induct_tac and exhaust_tac for induction (or case
285 analysis) over datatypes and the natural numbers;
287 * the datatype declaration of type T now defines the recursor T_rec;
289 * simplification automatically does freeness reasoning for datatype
292 * automatic type-inference, with AddTCs command to insert new
295 * datatype introduction rules are now added as Safe Introduction rules
298 * the syntax "if P then x else y" is now available in addition to
302 *** Internal programming interfaces ***
304 * tuned simplifier trace output; new flag debug_simp;
306 * structures Vartab / Termtab (instances of TableFun) offer efficient
307 tables indexed by indexname_ord / term_ord (compatible with aconv);
309 * AxClass.axclass_tac lost the theory argument;
311 * tuned current_goals_markers semantics: begin / end goal avoids
312 printing empty lines;
314 * removed prs and prs_fn hook, which was broken because it did not
315 include \n in its semantics, forcing writeln to add one
316 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
317 string -> unit if you really want to output text without newline;
319 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
320 plain output, interface builders may have to enable 'isabelle_font'
321 mode to get Isabelle font glyphs as before;
323 * refined token_translation interface; INCOMPATIBILITY: output length
324 now of type real instead of int;
326 * theory loader actions may be traced via new ThyInfo.add_hook
327 interface (see src/Pure/Thy/thy_info.ML); example application: keep
328 your own database of information attached to *whole* theories -- as
329 opposed to intra-theory data slots offered via TheoryDataFun;
331 * proper handling of dangling sort hypotheses (at last!);
332 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
333 extra sort hypotheses that can be witnessed from the type signature;
334 the force_strip_shyps flag is gone, any remaining shyps are simply
335 left in the theorem (with a warning issued by strip_shyps_warning);
339 New in Isabelle98-1 (October 1998)
340 ----------------------------------
342 *** Overview of INCOMPATIBILITIES (see below for more details) ***
344 * several changes of automated proof tools;
346 * HOL: major changes to the inductive and datatype packages, including
347 some minor incompatibilities of theory syntax;
349 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
352 * HOL: removed duplicate thms in Arith:
353 less_imp_add_less should be replaced by trans_less_add1
354 le_imp_add_le should be replaced by trans_le_add1
356 * HOL: unary minus is now overloaded (new type constraints may be
359 * HOL and ZF: unary minus for integers is now #- instead of #~. In
360 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
361 now taken as an integer constant.
363 * Pure: ML function 'theory_of' renamed to 'theory';
369 1. Asm_full_simp_tac is now more aggressive.
370 1. It will sometimes reorient premises if that increases their power to
372 2. It does no longer proceed strictly from left to right but may also
373 rotate premises to achieve further simplification.
374 For compatibility reasons there is now Asm_lr_simp_tac which is like the
375 old Asm_full_simp_tac in that it does not rotate premises.
376 2. The simplifier now knows a little bit about nat-arithmetic.
378 * Classical reasoner: wrapper mechanism for the classical reasoner now
379 allows for selected deletion of wrappers, by introduction of names for
380 wrapper functionals. This implies that addbefore, addSbefore,
381 addaltern, and addSaltern now take a pair (name, tactic) as argument,
382 and that adding two tactics with the same name overwrites the first
383 one (emitting a warning).
384 type wrapper = (int -> tactic) -> (int -> tactic)
385 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
386 addWrapper, addSWrapper: claset * (string * wrapper) -> claset
387 delWrapper, delSWrapper: claset * string -> claset
388 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
390 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
391 semantics; addbefore now affects only the unsafe part of step_tac
392 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
393 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
396 * Classical reasoner: setwrapper to setWrapper and compwrapper to
397 compWrapper; added safe wrapper (and access functions for it);
399 * HOL/split_all_tac is now much faster and fails if there is nothing
400 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
401 and the names of the automatically generated variables have changed.
402 split_all_tac has moved within claset() from unsafe wrappers to safe
403 wrappers, which means that !!-bound variables are split much more
404 aggressively, and safe_tac and clarify_tac now split such variables.
405 If this splitting is not appropriate, use delSWrapper "split_all_tac".
406 Note: the same holds for record_split_tac, which does the job of
407 split_all_tac for record fields.
409 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
410 permanently to the default simpset using Addsplits just like
411 Addsimps. They can be removed via Delsplits just like
412 Delsimps. Lower-case versions are also available.
414 * HOL/Simplifier: The rule split_if is now part of the default
415 simpset. This means that the simplifier will eliminate all occurrences
416 of if-then-else in the conclusion of a goal. To prevent this, you can
417 either remove split_if completely from the default simpset by
418 `Delsplits [split_if]' or remove it in a specific call of the
419 simplifier using `... delsplits [split_if]'. You can also add/delete
420 other case splitting rules to/from the default simpset: every datatype
421 generates suitable rules `split_t_case' and `split_t_case_asm' (where
422 t is the name of the datatype).
424 * Classical reasoner / Simplifier combination: new force_tac (and
425 derivatives Force_tac, force) combines rewriting and classical
426 reasoning (and whatever other tools) similarly to auto_tac, but is
427 aimed to solve the given subgoal completely.
432 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
433 and `goalw': the theory is no longer needed as an explicit argument -
434 the current theory context is used; assumptions are no longer returned
435 at the ML-level unless one of them starts with ==> or !!; it is
436 recommended to convert to these new commands using isatool fixgoal
437 (backup your sources first!);
439 * new top-level commands 'thm' and 'thms' for retrieving theorems from
440 the current theory context, and 'theory' to lookup stored theories;
442 * new theory section 'locale' for declaring constants, assumptions and
443 definitions that have local scope;
445 * new theory section 'nonterminals' for purely syntactic types;
447 * new theory section 'setup' for generic ML setup functions
448 (e.g. package initialization);
450 * the distribution now includes Isabelle icons: see
451 lib/logo/isabelle-{small,tiny}.xpm;
453 * isatool install - install binaries with absolute references to
456 * isatool logo -- create instances of the Isabelle logo (as EPS);
458 * print mode 'emacs' reserved for Isamode;
460 * support multiple print (ast) translations per constant name;
462 * theorems involving oracles are now printed with a suffixed [!];
467 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
469 * HOL/inductive package reorganized and improved: now supports mutual
475 oddI "n : EVEN ==> Suc n : ODD"
476 evenI "n : ODD ==> Suc n : EVEN"
478 new theorem list "elims" contains an elimination rule for each of the
479 recursive sets; inductive definitions now handle disjunctive premises
482 INCOMPATIBILITIES: requires Inductive as an ancestor; component
483 "mutual_induct" no longer exists - the induction rule is always
484 contained in "induct";
487 * HOL/datatype package re-implemented and greatly improved: now
488 supports mutually recursive datatypes such as
491 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
492 | SUM ('a aexp) ('a aexp)
493 | DIFF ('a aexp) ('a aexp)
496 'a bexp = LESS ('a aexp) ('a aexp)
497 | AND ('a bexp) ('a bexp)
498 | OR ('a bexp) ('a bexp)
500 as well as indirectly recursive datatypes such as
503 ('a, 'b) term = Var 'a
504 | App 'b ((('a, 'b) term) list)
506 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs
507 induction on mutually / indirectly recursive datatypes.
509 Primrec equations are now stored in theory and can be accessed via
510 <function_name>.simps.
514 - Theories using datatypes must now have theory Datatype as an
516 - The specific <typename>.induct_tac no longer exists - use the
517 generic induct_tac instead.
518 - natE has been renamed to nat.exhaust - use exhaust_tac
519 instead of res_inst_tac ... natE. Note that the variable
520 names in nat.exhaust differ from the names in natE, this
521 may cause some "fragile" proofs to fail.
522 - The theorems split_<typename>_case and split_<typename>_case_asm
523 have been renamed to <typename>.split and <typename>.split_asm.
524 - Since default sorts of type variables are now handled correctly,
525 some datatype definitions may have to be annotated with explicit
527 - Primrec definitions no longer require function name and type
528 of recursive argument.
530 Consider using isatool fixdatatype to adapt your theories and proof
531 scripts to the new package (backup your sources first!).
534 * HOL/record package: considerably improved implementation; now
535 includes concrete syntax for record types, terms, updates; theorems
536 for surjective pairing and splitting !!-bound record variables; proof
537 support is as follows:
539 1) standard conversions (selectors or updates applied to record
540 constructor terms) are part of the standard simpset;
542 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
543 made part of standard simpset and claset via addIffs;
545 3) a tactic for record field splitting (record_split_tac) is part of
546 the standard claset (addSWrapper);
548 To get a better idea about these rules you may retrieve them via
549 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
550 the name of your record type.
552 The split tactic 3) conceptually simplifies by the following rule:
554 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
556 Thus any record variable that is bound by meta-all will automatically
557 blow up into some record constructor term, consequently the
558 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall
559 solve record problems automatically.
562 * reorganized the main HOL image: HOL/Integ and String loaded by
563 default; theory Main includes everything;
565 * automatic simplification of integer sums and comparisons, using cancellation;
567 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
569 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
571 * many new identities for unions, intersections, set difference, etc.;
573 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
574 called split_if, split_split, split_sum_case and split_nat_case (to go
577 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
578 (?x::unit) = (); this is made part of the default simpset, which COULD
579 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
580 'Delsimprocs [unit_eq_proc];' as last resort); also note that
581 unit_abs_eta_conv is added in order to counter the effect of
582 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
585 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
588 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
589 It and 'sym RS equals0D' are now in the default claset, giving automatic
590 disjointness reasoning but breaking a few old proofs.
592 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
593 to 'converse' from 'inverse' (for compatibility with ZF and some
596 * HOL/recdef can now declare non-recursive functions, with {} supplied as
597 the well-founded relation;
599 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
600 Compl A. The "Compl" syntax remains available as input syntax for this
603 * HOL/Update: new theory of function updates:
604 f(a:=b) == %x. if x=a then b else f x
605 may also be iterated as in f(a:=b,c:=d,...);
607 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
610 - new function list_update written xs[i:=v] that updates the i-th
611 list position. May also be iterated as in xs[i:=a,j:=b,...].
612 - new function `upt' written [i..j(] which generates the list
613 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
614 bound write [i..j], which is a shorthand for [i..j+1(].
615 - new lexicographic orderings and corresponding wellfoundedness theorems.
618 - removed 'pred' (predecessor) function;
619 - generalized some theorems about n-1;
620 - many new laws about "div" and "mod";
621 - new laws about greatest common divisors (see theory ex/Primes);
623 * HOL/Relation: renamed the relational operator r^-1 "converse"
624 instead of "inverse";
626 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
627 of the multiset ordering;
629 * directory HOL/Real: a construction of the reals using Dedekind cuts
630 (not included by default);
632 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
634 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
635 programs, i.e. different program variables may have different types.
637 * calling (stac rew i) now fails if "rew" has no effect on the goal
638 [previously, this check worked only if the rewrite rule was unconditional]
639 Now rew can involve either definitions or equalities (either == or =).
644 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
645 only the theorems proved on ZF.ML;
647 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
648 It and 'sym RS equals0D' are now in the default claset, giving automatic
649 disjointness reasoning but breaking a few old proofs.
651 * ZF/Update: new theory of function updates
652 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)
653 may also be iterated as in f(a:=b,c:=d,...);
655 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.
657 * calling (stac rew i) now fails if "rew" has no effect on the goal
658 [previously, this check worked only if the rewrite rule was unconditional]
659 Now rew can involve either definitions or equalities (either == or =).
661 * case_tac provided for compatibility with HOL
662 (like the old excluded_middle_tac, but with subgoals swapped)
665 *** Internal programming interfaces ***
667 * Pure: several new basic modules made available for general use, see
668 also src/Pure/README;
670 * improved the theory data mechanism to support encapsulation (data
671 kind name replaced by private Object.kind, acting as authorization
672 key); new type-safe user interface via functor TheoryDataFun; generic
673 print_data function becomes basically useless;
675 * removed global_names compatibility flag -- all theory declarations
676 are qualified by default;
678 * module Pure/Syntax now offers quote / antiquote translation
679 functions (useful for Hoare logic etc. with implicit dependencies);
680 see HOL/ex/Antiquote for an example use;
682 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
685 * new tactical CHANGED_GOAL for checking that a tactic modifies a
688 * Display.print_goals function moved to Locale.print_goals;
690 * standard print function for goals supports current_goals_markers
691 variable for marking begin of proof, end of proof, start of goal; the
692 default is ("", "", ""); setting current_goals_markers := ("<proof>",
693 "</proof>", "<goal>") causes SGML like tagged proof state printing,
698 New in Isabelle98 (January 1998)
699 --------------------------------
701 *** Overview of INCOMPATIBILITIES (see below for more details) ***
703 * changed lexical syntax of terms / types: dots made part of long
704 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
706 * simpset (and claset) reference variable replaced by functions
707 simpset / simpset_ref;
709 * no longer supports theory aliases (via merge) and non-trivial
710 implicit merge of thms' signatures;
712 * most internal names of constants changed due to qualified names;
714 * changed Pure/Sequence interface (see Pure/seq.ML);
717 *** General Changes ***
719 * hierachically structured name spaces (for consts, types, axms, thms
720 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
721 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
722 isatool fixdots ensures space after dots (e.g. "%x. x"); set
723 long_names for fully qualified output names; NOTE: ML programs
724 (special tactics, packages etc.) referring to internal names may have
725 to be adapted to cope with fully qualified names; in case of severe
726 backward campatibility problems try setting 'global_names' at compile
727 time to have enrything declared within a flat name space; one may also
728 fine tune name declarations in theories via the 'global' and 'local'
731 * reimplemented the implicit simpset and claset using the new anytype
732 data filed in signatures; references simpset:simpset ref etc. are
733 replaced by functions simpset:unit->simpset and
734 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
735 to patch your ML files accordingly;
737 * HTML output now includes theory graph data for display with Java
738 applet or isatool browser; data generated automatically via isatool
739 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
741 * defs may now be conditional; improved rewrite_goals_tac to handle
742 conditional equations;
744 * defs now admits additional type arguments, using TYPE('a) syntax;
746 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
747 creates a new theory node; implicit merge of thms' signatures is
748 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
749 transfer:theory->thm->thm in (rare) cases;
751 * improved handling of draft signatures / theories; draft thms (and
752 ctyps, cterms) are automatically promoted to real ones;
754 * slightly changed interfaces for oracles: admit many per theory, named
755 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
757 * print_goals: optional output of const types (set show_consts and
760 * improved output of warnings (###) and errors (***);
762 * subgoal_tac displays a warning if the new subgoal has type variables;
764 * removed old README and Makefiles;
766 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
768 * removed obsolete init_pps and init_database;
770 * deleted the obsolete tactical STATE, which was declared by
771 fun STATE tacfun st = tacfun st st;
773 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
774 (which abbreviates $HOME);
776 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
777 use isatool fixseq to adapt your ML programs (this works for fully
778 qualified references to the Sequence structure only!);
780 * use_thy no longer requires writable current directory; it always
781 reloads .ML *and* .thy file, if either one is out of date;
784 *** Classical Reasoner ***
786 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
787 tactics that use classical reasoning to simplify a subgoal without
788 splitting it into several subgoals;
790 * Safe_tac: like safe_tac but uses the default claset;
795 * added simplification meta rules:
796 (asm_)(full_)simplify: simpset -> thm -> thm;
798 * simplifier.ML no longer part of Pure -- has to be loaded by object
801 * added prems argument to simplification procedures;
803 * HOL, FOL, ZF: added infix function `addsplits':
804 instead of `<simpset> setloop (split_tac <thms>)'
805 you can simply write `<simpset> addsplits <thms>'
810 * TYPE('a) syntax for type reflection terms;
812 * no longer handles consts with name "" -- declare as 'syntax' instead;
814 * pretty printer: changed order of mixfix annotation preference (again!);
816 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
821 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
822 with `addloop' of the simplifier to faciliate case splitting in premises.
824 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
826 * HOL/Auth: new protocol proofs including some for the Internet
829 * HOL/Map: new theory of `maps' a la VDM;
831 * HOL/simplifier: simplification procedures nat_cancel_sums for
832 cancelling out common nat summands from =, <, <= (in)equalities, or
833 differences; simplification procedures nat_cancel_factor for
834 cancelling common factor from =, <, <= (in)equalities over natural
835 sums; nat_cancel contains both kinds of procedures, it is installed by
836 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
838 * HOL/simplifier: terms of the form
839 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)
841 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
842 and those of the form
843 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)
845 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
848 Each datatype `t' now comes with a theorem `split_t_case' of the form
850 P(t_case f1 ... fn x) =
851 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
853 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
856 and a theorem `split_t_case_asm' of the form
858 P(t_case f1 ... fn x) =
859 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
861 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
863 which can be added to a simpset via `addsplits'. The existing theorems
864 expand_list_case and expand_option_case have been renamed to
865 split_list_case and split_option_case.
868 - `pred n' is automatically converted to `n-1'.
869 Users are strongly encouraged not to use `pred' any longer,
870 because it will disappear altogether at some point.
871 - Users are strongly encouraged to write "0 < n" rather than
872 "n ~= 0". Theorems and proof tools have been modified towards this
876 the function "set_of_list" has been renamed "set" (and its theorems too);
877 the function "nth" now takes its arguments in the reverse order and
878 has acquired the infix notation "!" as in "xs!n".
880 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
882 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
883 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);
885 * HOL/record: extensible records with schematic structural subtyping
886 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
887 still lacks various theorems and concrete record syntax;
892 * removed "axioms" and "generated by" sections;
894 * replaced "ops" section by extended "consts" section, which is capable of
895 handling the continuous function space "->" directly;
898 . proves theorems immediately and stores them in the theory,
899 . creates hierachical name space,
900 . now uses normal mixfix annotations (instead of cinfix...),
901 . minor changes to some names and values (for consistency),
902 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
903 . separator between mutual domain defs: changed "," to "and",
904 . improved handling of sort constraints; now they have to
905 appear on the left-hand side of the equations only;
907 * fixed LAM <x,y,zs>.b syntax;
909 * added extended adm_tac to simplifier in HOLCF -- can now discharge
910 adm (%x. P (t x)), where P is chainfinite and t continuous;
915 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
916 with `addloop' of the simplifier to faciliate case splitting in premises.
918 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
919 in HOL, they strip ALL and --> from proved theorems;
923 New in Isabelle94-8 (May 1997)
924 ------------------------------
926 *** General Changes ***
928 * new utilities to build / run / maintain Isabelle etc. (in parts
929 still somewhat experimental); old Makefiles etc. still functional;
931 * new 'Isabelle System Manual';
933 * INSTALL text, together with ./configure and ./build scripts;
935 * reimplemented type inference for greater efficiency, better error
936 messages and clean internal interface;
938 * prlim command for dealing with lots of subgoals (an easier way of
939 setting goals_limit);
944 * supports alternative (named) syntax tables (parser and pretty
945 printer); internal interface is provided by add_modesyntax(_i);
947 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
948 be used in conjunction with the Isabelle symbol font; uses the
949 "symbols" syntax table;
951 * added token_translation interface (may translate name tokens in
952 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
953 the current print_mode); IMPORTANT: user print translation functions
954 are responsible for marking newly introduced bounds
955 (Syntax.mark_boundT);
957 * token translations for modes "xterm" and "xterm_color" that display
958 names in bold, underline etc. or colors (which requires a color
961 * infixes may now be declared with names independent of their syntax;
963 * added typed_print_translation (like print_translation, but may
964 access type of constant);
967 *** Classical Reasoner ***
969 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has
970 some limitations. Blast_tac...
971 + ignores addss, addbefore, addafter; this restriction is intrinsic
972 + ignores elimination rules that don't have the correct format
973 (the conclusion MUST be a formula variable)
974 + ignores types, which can make HOL proofs fail
975 + rules must not require higher-order unification, e.g. apply_type in ZF
976 [message "Function Var's argument not a bound variable" relates to this]
977 + its proof strategy is more general but can actually be slower
979 * substitution with equality assumptions no longer permutes other
982 * minor changes in semantics of addafter (now called addaltern); renamed
983 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
984 (and access functions for it);
986 * improved combination of classical reasoner and simplifier:
987 + functions for handling clasimpsets
988 + improvement of addss: now the simplifier is called _after_ the
990 + safe variant of addss called addSss: uses safe simplifications
991 _during_ the safe steps. It is more complete as it allows multiple
992 instantiations of unknowns (e.g. with slow_tac).
996 * added interface for simplification procedures (functions that
997 produce *proven* rewrite rules on the fly, depending on current
1000 * ordering on terms as parameter (used for ordered rewriting);
1002 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
1004 * the solver is now split into a safe and an unsafe part.
1005 This should be invisible for the normal user, except that the
1006 functions setsolver and addsolver have been renamed to setSolver and
1007 addSolver; added safe_asm_full_simp_tac;
1012 * a generic induction tactic `induct_tac' which works for all datatypes and
1013 also for type `nat';
1015 * a generic case distinction tactic `exhaust_tac' which works for all
1016 datatypes and also for type `nat';
1018 * each datatype comes with a function `size';
1020 * patterns in case expressions allow tuple patterns as arguments to
1021 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
1023 * primrec now also works with type nat;
1025 * recdef: a new declaration form, allows general recursive functions to be
1026 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
1028 * the constant for negation has been renamed from "not" to "Not" to
1029 harmonize with FOL, ZF, LK, etc.;
1031 * HOL/ex/LFilter theory of a corecursive "filter" functional for
1034 * HOL/Modelcheck demonstrates invocation of model checker oracle;
1036 * HOL/ex/Ring.thy declares cring_simp, which solves equational
1037 problems in commutative rings, using axiomatic type classes for + and *;
1039 * more examples in HOL/MiniML and HOL/Auth;
1041 * more default rewrite rules for quantifiers, union/intersection;
1043 * a new constant `arbitrary == @x.False';
1045 * HOLCF/IOA replaces old HOL/IOA;
1047 * HOLCF changes: derived all rules and arities
1048 + axiomatic type classes instead of classes
1049 + typedef instead of faking type definitions
1050 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
1051 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
1052 + eliminated the types void, one, tr
1053 + use unit lift and bool lift (with translations) instead of one and tr
1054 + eliminated blift from Lift3.thy (use Def instead of blift)
1055 all eliminated rules are derived as theorems --> no visible changes ;
1060 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default
1061 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back
1062 as ZF_cs addSIs [equalityI];
1066 New in Isabelle94-7 (November 96)
1067 ---------------------------------
1069 * allowing negative levels (as offsets) in prlev and choplev;
1071 * super-linear speedup for large simplifications;
1073 * FOL, ZF and HOL now use miniscoping: rewriting pushes
1074 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
1075 FAIL); can suppress it using the command Delsimps (ex_simps @
1076 all_simps); De Morgan laws are also now included, by default;
1078 * improved printing of ==> : ~:
1080 * new object-logic "Sequents" adds linear logic, while replacing LK
1081 and Modal (thanks to Sara Kalvala);
1083 * HOL/Auth: correctness proofs for authentication protocols;
1085 * HOL: new auto_tac combines rewriting and classical reasoning (many
1086 examples on HOL/Auth);
1088 * HOL: new command AddIffs for declaring theorems of the form P=Q to
1089 the rewriter and classical reasoner simultaneously;
1091 * function uresult no longer returns theorems in "standard" format;
1092 regain previous version by: val uresult = standard o uresult;
1099 * oracles -- these establish an interface between Isabelle and trusted
1100 external reasoners, which may deliver results as theorems;
1102 * proof objects (in particular record all uses of oracles);
1104 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
1106 * "constdefs" section in theory files;
1108 * "primrec" section (HOL) no longer requires names;
1110 * internal type "tactic" now simply "thm -> thm Sequence.seq";
1117 * reduced space requirements;
1119 * automatic HTML generation from theories;
1121 * theory files no longer require "..." (quotes) around most types;
1123 * new examples, including two proofs of the Church-Rosser theorem;
1125 * non-curried (1994) version of HOL is no longer distributed;
1132 * greatly reduced space requirements;
1134 * theory files (.thy) no longer require \...\ escapes at line breaks;
1136 * searchable theorem database (see the section "Retrieving theorems" on
1137 page 8 of the Reference Manual);
1139 * new examples, including Grabczewski's monumental case study of the
1142 * The previous version of HOL renamed to Old_HOL;
1144 * The new version of HOL (previously called CHOL) uses a curried syntax
1145 for functions. Application looks like f a b instead of f(a,b);
1147 * Mutually recursive inductive definitions finally work in HOL;
1149 * In ZF, pattern-matching on tuples is now available in all abstractions and
1150 translates to the operator "split";
1157 * new infix operator, addss, allowing the classical reasoner to
1158 perform simplification at each step of its search. Example:
1159 fast_tac (cs addss ss)
1161 * a new logic, CHOL, the same as HOL, but with a curried syntax
1162 for functions. Application looks like f a b instead of f(a,b). Also pairs
1163 look like (a,b) instead of <a,b>;
1165 * PLEASE NOTE: CHOL will eventually replace HOL!
1167 * In CHOL, pattern-matching on tuples is now available in all abstractions.
1168 It translates to the operator "split". A new theory of integers is available;
1170 * In ZF, integer numerals now denote two's-complement binary integers.
1171 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;
1173 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
1174 of the Axiom of Choice;
1181 * Significantly faster resolution;
1183 * the different sections in a .thy file can now be mixed and repeated
1186 * Database of theorems for FOL, HOL and ZF. New
1187 commands including qed, qed_goal and bind_thm store theorems in the database.
1189 * Simple database queries: return a named theorem (get_thm) or all theorems of
1190 a given theory (thms_of), or find out what theory a theorem was proved in
1193 * Bugs fixed in the inductive definition and datatype packages;
1195 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
1196 and HOL_dup_cs obsolete;
1198 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
1201 * Simpler definition of function space in ZF;
1203 * new results about cardinal and ordinal arithmetic in ZF;
1205 * 'subtype' facility in HOL for introducing new types as subsets of existing