NEWS
author wenzelm
Mon Aug 23 16:50:10 1999 +0200 (1999-08-23)
changeset 7326 a1555491a966
parent 7324 6cb0d0202298
child 7327 596318fdb379
permissions -rw-r--r--
record_simproc;
     1 
     2 Isabelle NEWS -- history user-relevant changes
     3 ==============================================
     4 
     5 New in this Isabelle version
     6 ----------------------------
     7 
     8 *** Overview of INCOMPATIBILITIES (see below for more details) ***
     9 
    10 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
    11 are no longer simplified.  (This allows the simplifier to unfold recursive
    12 functional programs.)  To restore the old behaviour, declare
    13 
    14     Delcongs [if_weak_cong];
    15 
    16 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
    17 complement;
    18 
    19 * HOL: the predicate "inj" is now defined by translation to "inj_on";
    20 
    21 * HOL/typedef: fixed type inference for representing set; type
    22 arguments now have to occur explicitly on the rhs as type constraints;
    23 
    24 * ZF: The con_defs part of an inductive definition may no longer refer
    25 to constants declared in the same theory;
    26 
    27 * HOL, ZF: the function mk_cases, generated by the inductive
    28 definition package, has lost an argument.  To simplify its result, it
    29 uses the default simpset instead of a supplied list of theorems.
    30 
    31 * HOL/List: the constructors of type list are now Nil and Cons;
    32 
    33 
    34 *** Proof tools ***
    35 
    36 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
    37 decision procedure for linear arithmetic. Currently it is used for
    38 types `nat' and `int' in HOL (see below) but can, should and will be
    39 instantiated for other types and logics as well.
    40 
    41 * The simplifier now accepts rewrite rules with flexible heads, eg
    42      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
    43   They are applied like any rule with a non-pattern lhs, i.e. by first-order
    44   matching.
    45 
    46 *** General ***
    47 
    48 * new Isabelle/Isar subsystem provides an alternative to traditional
    49 tactical theorem proving; together with the ProofGeneral/isar user
    50 interface it offers an interactive environment for developing human
    51 readable proof documents (Isar == Intelligible semi-automated
    52 reasoning); see isatool doc isar-ref and
    53 http://isabelle.in.tum.de/Isar/ for more information;
    54 
    55 * native support for Proof General, both for classic Isabelle and
    56 Isabelle/Isar (the latter is slightly better supported and more
    57 robust);
    58 
    59 * Isabelle manuals now also available as PDF;
    60 
    61 * improved browser info generation: better HTML markup (including
    62 colors), graph views in several sizes; isatool usedir now provides a
    63 proper interface for user theories (via -P option);
    64 
    65 * theory loader rewritten from scratch (may not be fully
    66 bug-compatible); old loadpath variable has been replaced by show_path,
    67 add_path, del_path, reset_path functions; new operations such as
    68 update_thy, touch_thy, remove_thy (see also isatool doc ref);
    69 
    70 * improved isatool install: option -k creates KDE application icon,
    71 option -p DIR installs standalone binaries;
    72 
    73 * added ML_PLATFORM setting (useful for cross-platform installations);
    74 more robust handling of platform specific ML images for SML/NJ;
    75 
    76 * path element specification '~~' refers to '$ISABELLE_HOME';
    77 
    78 * in locales, the "assumes" and "defines" parts may be omitted if
    79 empty;
    80 
    81 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
    82 long arrows);
    83 
    84 * new print_mode "HTML";
    85 
    86 * new flag show_tags controls display of tags of theorems (which are
    87 basically just comments that may be attached by some tools);
    88 
    89 * Isamode 2.6 requires patch to accomodate change of Isabelle font
    90 mode and goal output format:
    91 
    92 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
    93 244c244
    94 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
    95 ---
    96 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
    97 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
    98 181c181
    99 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
   100 ---
   101 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
   102 
   103 
   104 *** HOL ***
   105 
   106 ** HOL arithmetic **
   107 
   108 * There are now decision procedures for linear arithmetic over nat and
   109 int:
   110 
   111 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
   112 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
   113 are treated as atomic; subformulae not involving type `nat' or `int'
   114 are ignored; quantified subformulae are ignored unless they are
   115 positive universal or negative existential. The tactic has to be
   116 invoked by hand and can be a little bit slow. In particular, the
   117 running time is exponential in the number of occurrences of `min' and
   118 `max', and `-' on `nat'.
   119 
   120 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
   121 (negated) (in)equalities among the premises and the conclusion into
   122 account (i.e. no compound formulae) and does not know about `min' and
   123 `max', and `-' on `nat'. It is fast and is used automatically by the
   124 simplifier.
   125 
   126 NB: At the moment, these decision procedures do not cope with mixed
   127 nat/int formulae where the two parts interact, such as `m < n ==>
   128 int(m) < int(n)'.
   129 
   130 * HOL/Numeral provides a generic theory of numerals (encoded
   131 efficiently as bit strings); setup for types nat/int/real is in place;
   132 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
   133 int, existing theories and proof scripts may require a few additional
   134 type constraints;
   135 
   136 * integer division and remainder can now be performed on constant
   137 arguments;
   138 
   139 * many properties of integer multiplication, division and remainder
   140 are now available;
   141 
   142 * An interface to the Stanford Validity Checker (SVC) is available through the
   143 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
   144 are proved automatically.  SVC must be installed separately, and its results
   145 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
   146 invocation of the underlying oracle).  For SVC see
   147   http://agamemnon.stanford.edu/~levitt/vc/index.html
   148 
   149 * IsaMakefile: the HOL-Real target now builds an actual image;
   150 
   151 
   152 ** HOL misc **
   153 
   154 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
   155 -- avoids syntactic ambiguities and treats state, transition, and
   156 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
   157 changed syntax and (many) tactics;
   158 
   159 * HOL/datatype: Now also handles arbitrarily branching datatypes
   160   (using function types) such as
   161 
   162   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
   163 
   164 * HOL/record: record_simproc (part of the default simpset) takes care
   165 of selectors applied to updated records; record_split_tac is no longer
   166 part of the default claset; COMPATIBILITY:
   167 
   168   claset_ref () := claset() addSWrapper record_split_wrapper;
   169   Delsimprocs [record_simproc]
   170 
   171 achieve the old bahaviour;
   172 
   173 * HOL/typedef: fixed type inference for representing set; type
   174 arguments now have to occur explicitly on the rhs as type constraints;
   175 
   176 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
   177 names rather than an ML expression;
   178 
   179 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
   180 supplied later.  Program schemes can be defined, such as
   181     "While B C s = (if B s then While B C (C s) else s)"
   182 where the well-founded relation can be chosen after B and C have been given.
   183 
   184 * HOL/List: the constructors of type list are now Nil and Cons;
   185 INCOMPATIBILITY: while [] and infix # syntax is still there, of
   186 course, ML tools referring to List.list.op # etc. have to be adapted;
   187 
   188 * HOL_quantifiers flag superseded by "HOL" print mode, which is
   189 disabled by default; run isabelle with option -m HOL to get back to
   190 the original Gordon/HOL-style output;
   191 
   192 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
   193 ALL x<=y. P, EX x<y. P, EX x<=y. P;
   194 
   195 * HOL basic syntax simplified (more orthogonal): all variants of
   196 All/Ex now support plain / symbolic / HOL notation; plain syntax for
   197 Eps operator is provided as well: "SOME x. P[x]";
   198 
   199 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
   200 
   201 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
   202 thus available for user theories;
   203 
   204 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
   205 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
   206 time;
   207 
   208 
   209 *** LK ***
   210 
   211 * the notation <<...>> is now available as a notation for sequences of
   212 formulas;
   213 
   214 * the simplifier is now installed
   215 
   216 * the axiom system has been generalized (thanks to Soren Heilmann) 
   217 
   218 * the classical reasoner now has a default rule database
   219 
   220 
   221 *** ZF ***
   222 
   223 * new primrec section allows primitive recursive functions to be given
   224 directly (as in HOL) over datatypes and the natural numbers;
   225 
   226 * new tactics induct_tac and exhaust_tac for induction (or case
   227 analysis) over datatypes and the natural numbers;
   228 
   229 * the datatype declaration of type T now defines the recursor T_rec;
   230 
   231 * simplification automatically does freeness reasoning for datatype
   232 constructors;
   233 
   234 * automatic type-inference, with AddTCs command to insert new
   235 type-checking rules;
   236 
   237 * datatype introduction rules are now added as Safe Introduction rules
   238 to the claset;
   239 
   240 * the syntax "if P then x else y" is now available in addition to
   241 if(P,x,y);
   242 
   243 
   244 *** Internal programming interfaces ***
   245 
   246 * AxClass.axclass_tac lost the theory argument;
   247 
   248 * tuned current_goals_markers semantics: begin / end goal avoids
   249 printing empty lines;
   250 
   251 * removed prs and prs_fn hook, which was broken because it did not
   252 include \n in its semantics, forcing writeln to add one
   253 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
   254 string -> unit if you really want to output text without newline;
   255 
   256 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
   257 plain output, interface builders may have to enable 'isabelle_font'
   258 mode to get Isabelle font glyphs as before;
   259 
   260 * refined token_translation interface; INCOMPATIBILITY: output length
   261 now of type real instead of int;
   262 
   263 * theory loader actions may be traced via new ThyInfo.add_hook
   264 interface (see src/Pure/Thy/thy_info.ML); example application: keep
   265 your own database of information attached to *whole* theories -- as
   266 opposed to intra-theory data slots offered via TheoryDataFun;
   267 
   268 
   269 
   270 New in Isabelle98-1 (October 1998)
   271 ----------------------------------
   272 
   273 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   274 
   275 * several changes of automated proof tools;
   276 
   277 * HOL: major changes to the inductive and datatype packages, including
   278 some minor incompatibilities of theory syntax;
   279 
   280 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
   281 called `inj_on';
   282 
   283 * HOL: removed duplicate thms in Arith:
   284   less_imp_add_less  should be replaced by  trans_less_add1
   285   le_imp_add_le      should be replaced by  trans_le_add1
   286 
   287 * HOL: unary minus is now overloaded (new type constraints may be
   288 required);
   289 
   290 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
   291 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
   292 now taken as an integer constant.
   293 
   294 * Pure: ML function 'theory_of' renamed to 'theory';
   295 
   296 
   297 *** Proof tools ***
   298 
   299 * Simplifier:
   300   1. Asm_full_simp_tac is now more aggressive.
   301      1. It will sometimes reorient premises if that increases their power to
   302         simplify.
   303      2. It does no longer proceed strictly from left to right but may also
   304         rotate premises to achieve further simplification.
   305      For compatibility reasons there is now Asm_lr_simp_tac which is like the
   306      old Asm_full_simp_tac in that it does not rotate premises.
   307   2. The simplifier now knows a little bit about nat-arithmetic.
   308 
   309 * Classical reasoner: wrapper mechanism for the classical reasoner now
   310 allows for selected deletion of wrappers, by introduction of names for
   311 wrapper functionals.  This implies that addbefore, addSbefore,
   312 addaltern, and addSaltern now take a pair (name, tactic) as argument,
   313 and that adding two tactics with the same name overwrites the first
   314 one (emitting a warning).
   315   type wrapper = (int -> tactic) -> (int -> tactic)
   316   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
   317   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
   318   delWrapper, delSWrapper: claset *  string            -> claset
   319   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
   320 
   321 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
   322 semantics; addbefore now affects only the unsafe part of step_tac
   323 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
   324 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
   325 by Force_tac;
   326 
   327 * Classical reasoner: setwrapper to setWrapper and compwrapper to
   328 compWrapper; added safe wrapper (and access functions for it);
   329 
   330 * HOL/split_all_tac is now much faster and fails if there is nothing
   331 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
   332 and the names of the automatically generated variables have changed.
   333 split_all_tac has moved within claset() from unsafe wrappers to safe
   334 wrappers, which means that !!-bound variables are split much more
   335 aggressively, and safe_tac and clarify_tac now split such variables.
   336 If this splitting is not appropriate, use delSWrapper "split_all_tac".
   337 Note: the same holds for record_split_tac, which does the job of
   338 split_all_tac for record fields.
   339 
   340 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
   341 permanently to the default simpset using Addsplits just like
   342 Addsimps. They can be removed via Delsplits just like
   343 Delsimps. Lower-case versions are also available.
   344 
   345 * HOL/Simplifier: The rule split_if is now part of the default
   346 simpset. This means that the simplifier will eliminate all occurrences
   347 of if-then-else in the conclusion of a goal. To prevent this, you can
   348 either remove split_if completely from the default simpset by
   349 `Delsplits [split_if]' or remove it in a specific call of the
   350 simplifier using `... delsplits [split_if]'.  You can also add/delete
   351 other case splitting rules to/from the default simpset: every datatype
   352 generates suitable rules `split_t_case' and `split_t_case_asm' (where
   353 t is the name of the datatype).
   354 
   355 * Classical reasoner / Simplifier combination: new force_tac (and
   356 derivatives Force_tac, force) combines rewriting and classical
   357 reasoning (and whatever other tools) similarly to auto_tac, but is
   358 aimed to solve the given subgoal completely.
   359 
   360 
   361 *** General ***
   362 
   363 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
   364 and `goalw': the theory is no longer needed as an explicit argument -
   365 the current theory context is used; assumptions are no longer returned
   366 at the ML-level unless one of them starts with ==> or !!; it is
   367 recommended to convert to these new commands using isatool fixgoal
   368 (backup your sources first!);
   369 
   370 * new top-level commands 'thm' and 'thms' for retrieving theorems from
   371 the current theory context, and 'theory' to lookup stored theories;
   372 
   373 * new theory section 'locale' for declaring constants, assumptions and
   374 definitions that have local scope;
   375 
   376 * new theory section 'nonterminals' for purely syntactic types;
   377 
   378 * new theory section 'setup' for generic ML setup functions
   379 (e.g. package initialization);
   380 
   381 * the distribution now includes Isabelle icons: see
   382 lib/logo/isabelle-{small,tiny}.xpm;
   383 
   384 * isatool install - install binaries with absolute references to
   385 ISABELLE_HOME/bin;
   386 
   387 * isatool logo -- create instances of the Isabelle logo (as EPS);
   388 
   389 * print mode 'emacs' reserved for Isamode;
   390 
   391 * support multiple print (ast) translations per constant name;
   392 
   393 * theorems involving oracles are now printed with a suffixed [!];
   394 
   395 
   396 *** HOL ***
   397 
   398 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
   399 
   400 * HOL/inductive package reorganized and improved: now supports mutual
   401 definitions such as
   402 
   403   inductive EVEN ODD
   404     intrs
   405       null "0 : EVEN"
   406       oddI "n : EVEN ==> Suc n : ODD"
   407       evenI "n : ODD ==> Suc n : EVEN"
   408 
   409 new theorem list "elims" contains an elimination rule for each of the
   410 recursive sets; inductive definitions now handle disjunctive premises
   411 correctly (also ZF);
   412 
   413 INCOMPATIBILITIES: requires Inductive as an ancestor; component
   414 "mutual_induct" no longer exists - the induction rule is always
   415 contained in "induct";
   416 
   417 
   418 * HOL/datatype package re-implemented and greatly improved: now
   419 supports mutually recursive datatypes such as
   420 
   421   datatype
   422     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
   423             | SUM ('a aexp) ('a aexp)
   424             | DIFF ('a aexp) ('a aexp)
   425             | NUM 'a
   426   and
   427     'a bexp = LESS ('a aexp) ('a aexp)
   428             | AND ('a bexp) ('a bexp)
   429             | OR ('a bexp) ('a bexp)
   430 
   431 as well as indirectly recursive datatypes such as
   432 
   433   datatype
   434     ('a, 'b) term = Var 'a
   435                   | App 'b ((('a, 'b) term) list)
   436 
   437 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
   438 induction on mutually / indirectly recursive datatypes.
   439 
   440 Primrec equations are now stored in theory and can be accessed via
   441 <function_name>.simps.
   442 
   443 INCOMPATIBILITIES:
   444 
   445   - Theories using datatypes must now have theory Datatype as an
   446     ancestor.
   447   - The specific <typename>.induct_tac no longer exists - use the
   448     generic induct_tac instead.
   449   - natE has been renamed to nat.exhaust - use exhaust_tac
   450     instead of res_inst_tac ... natE. Note that the variable
   451     names in nat.exhaust differ from the names in natE, this
   452     may cause some "fragile" proofs to fail.
   453   - The theorems split_<typename>_case and split_<typename>_case_asm
   454     have been renamed to <typename>.split and <typename>.split_asm.
   455   - Since default sorts of type variables are now handled correctly,
   456     some datatype definitions may have to be annotated with explicit
   457     sort constraints.
   458   - Primrec definitions no longer require function name and type
   459     of recursive argument.
   460 
   461 Consider using isatool fixdatatype to adapt your theories and proof
   462 scripts to the new package (backup your sources first!).
   463 
   464 
   465 * HOL/record package: considerably improved implementation; now
   466 includes concrete syntax for record types, terms, updates; theorems
   467 for surjective pairing and splitting !!-bound record variables; proof
   468 support is as follows:
   469 
   470   1) standard conversions (selectors or updates applied to record
   471 constructor terms) are part of the standard simpset;
   472 
   473   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
   474 made part of standard simpset and claset via addIffs;
   475 
   476   3) a tactic for record field splitting (record_split_tac) is part of
   477 the standard claset (addSWrapper);
   478 
   479 To get a better idea about these rules you may retrieve them via
   480 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
   481 the name of your record type.
   482 
   483 The split tactic 3) conceptually simplifies by the following rule:
   484 
   485   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
   486 
   487 Thus any record variable that is bound by meta-all will automatically
   488 blow up into some record constructor term, consequently the
   489 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
   490 solve record problems automatically.
   491 
   492 
   493 * reorganized the main HOL image: HOL/Integ and String loaded by
   494 default; theory Main includes everything;
   495 
   496 * automatic simplification of integer sums and comparisons, using cancellation;
   497 
   498 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
   499 
   500 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
   501 
   502 * many new identities for unions, intersections, set difference, etc.;
   503 
   504 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
   505 called split_if, split_split, split_sum_case and split_nat_case (to go
   506 with add/delsplits);
   507 
   508 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
   509 (?x::unit) = (); this is made part of the default simpset, which COULD
   510 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
   511 'Delsimprocs [unit_eq_proc];' as last resort); also note that
   512 unit_abs_eta_conv is added in order to counter the effect of
   513 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
   514 %u.f();
   515 
   516 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
   517 makes more sense);
   518 
   519 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   520   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   521   disjointness reasoning but breaking a few old proofs.
   522 
   523 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
   524 to 'converse' from 'inverse' (for compatibility with ZF and some
   525 literature);
   526 
   527 * HOL/recdef can now declare non-recursive functions, with {} supplied as
   528 the well-founded relation;
   529 
   530 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
   531     Compl A.  The "Compl" syntax remains available as input syntax for this
   532     release ONLY.
   533 
   534 * HOL/Update: new theory of function updates:
   535     f(a:=b) == %x. if x=a then b else f x
   536 may also be iterated as in f(a:=b,c:=d,...);
   537 
   538 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
   539 
   540 * HOL/List:
   541   - new function list_update written xs[i:=v] that updates the i-th
   542     list position. May also be iterated as in xs[i:=a,j:=b,...].
   543   - new function `upt' written [i..j(] which generates the list
   544     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
   545     bound write [i..j], which is a shorthand for [i..j+1(].
   546   - new lexicographic orderings and corresponding wellfoundedness theorems.
   547 
   548 * HOL/Arith:
   549   - removed 'pred' (predecessor) function;
   550   - generalized some theorems about n-1;
   551   - many new laws about "div" and "mod";
   552   - new laws about greatest common divisors (see theory ex/Primes);
   553 
   554 * HOL/Relation: renamed the relational operator r^-1 "converse"
   555 instead of "inverse";
   556 
   557 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
   558   of the multiset ordering;
   559 
   560 * directory HOL/Real: a construction of the reals using Dedekind cuts
   561   (not included by default);
   562 
   563 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
   564 
   565 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
   566   programs, i.e. different program variables may have different types.
   567 
   568 * calling (stac rew i) now fails if "rew" has no effect on the goal
   569   [previously, this check worked only if the rewrite rule was unconditional]
   570   Now rew can involve either definitions or equalities (either == or =).
   571 
   572 
   573 *** ZF ***
   574 
   575 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
   576   only the theorems proved on ZF.ML;
   577 
   578 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   579   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   580   disjointness reasoning but breaking a few old proofs.
   581 
   582 * ZF/Update: new theory of function updates
   583     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
   584   may also be iterated as in f(a:=b,c:=d,...);
   585 
   586 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
   587 
   588 * calling (stac rew i) now fails if "rew" has no effect on the goal
   589   [previously, this check worked only if the rewrite rule was unconditional]
   590   Now rew can involve either definitions or equalities (either == or =).
   591 
   592 * case_tac provided for compatibility with HOL
   593     (like the old excluded_middle_tac, but with subgoals swapped)
   594 
   595 
   596 *** Internal programming interfaces ***
   597 
   598 * Pure: several new basic modules made available for general use, see
   599 also src/Pure/README;
   600 
   601 * improved the theory data mechanism to support encapsulation (data
   602 kind name replaced by private Object.kind, acting as authorization
   603 key); new type-safe user interface via functor TheoryDataFun; generic
   604 print_data function becomes basically useless;
   605 
   606 * removed global_names compatibility flag -- all theory declarations
   607 are qualified by default;
   608 
   609 * module Pure/Syntax now offers quote / antiquote translation
   610 functions (useful for Hoare logic etc. with implicit dependencies);
   611 see HOL/ex/Antiquote for an example use;
   612 
   613 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
   614 cterm -> thm;
   615 
   616 * new tactical CHANGED_GOAL for checking that a tactic modifies a
   617 subgoal;
   618 
   619 * Display.print_goals function moved to Locale.print_goals;
   620 
   621 * standard print function for goals supports current_goals_markers
   622 variable for marking begin of proof, end of proof, start of goal; the
   623 default is ("", "", ""); setting current_goals_markers := ("<proof>",
   624 "</proof>", "<goal>") causes SGML like tagged proof state printing,
   625 for example;
   626 
   627 
   628 
   629 New in Isabelle98 (January 1998)
   630 --------------------------------
   631 
   632 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   633 
   634 * changed lexical syntax of terms / types: dots made part of long
   635 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
   636 
   637 * simpset (and claset) reference variable replaced by functions
   638 simpset / simpset_ref;
   639 
   640 * no longer supports theory aliases (via merge) and non-trivial
   641 implicit merge of thms' signatures;
   642 
   643 * most internal names of constants changed due to qualified names;
   644 
   645 * changed Pure/Sequence interface (see Pure/seq.ML);
   646 
   647 
   648 *** General Changes ***
   649 
   650 * hierachically structured name spaces (for consts, types, axms, thms
   651 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
   652 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
   653 isatool fixdots ensures space after dots (e.g. "%x. x"); set
   654 long_names for fully qualified output names; NOTE: ML programs
   655 (special tactics, packages etc.) referring to internal names may have
   656 to be adapted to cope with fully qualified names; in case of severe
   657 backward campatibility problems try setting 'global_names' at compile
   658 time to have enrything declared within a flat name space; one may also
   659 fine tune name declarations in theories via the 'global' and 'local'
   660 section;
   661 
   662 * reimplemented the implicit simpset and claset using the new anytype
   663 data filed in signatures; references simpset:simpset ref etc. are
   664 replaced by functions simpset:unit->simpset and
   665 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
   666 to patch your ML files accordingly;
   667 
   668 * HTML output now includes theory graph data for display with Java
   669 applet or isatool browser; data generated automatically via isatool
   670 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
   671 
   672 * defs may now be conditional; improved rewrite_goals_tac to handle
   673 conditional equations;
   674 
   675 * defs now admits additional type arguments, using TYPE('a) syntax;
   676 
   677 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
   678 creates a new theory node; implicit merge of thms' signatures is
   679 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
   680 transfer:theory->thm->thm in (rare) cases;
   681 
   682 * improved handling of draft signatures / theories; draft thms (and
   683 ctyps, cterms) are automatically promoted to real ones;
   684 
   685 * slightly changed interfaces for oracles: admit many per theory, named
   686 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
   687 
   688 * print_goals: optional output of const types (set show_consts and
   689 show_types);
   690 
   691 * improved output of warnings (###) and errors (***);
   692 
   693 * subgoal_tac displays a warning if the new subgoal has type variables;
   694 
   695 * removed old README and Makefiles;
   696 
   697 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
   698 
   699 * removed obsolete init_pps and init_database;
   700 
   701 * deleted the obsolete tactical STATE, which was declared by
   702     fun STATE tacfun st = tacfun st st;
   703 
   704 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
   705 (which abbreviates $HOME);
   706 
   707 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
   708 use isatool fixseq to adapt your ML programs (this works for fully
   709 qualified references to the Sequence structure only!);
   710 
   711 * use_thy no longer requires writable current directory; it always
   712 reloads .ML *and* .thy file, if either one is out of date;
   713 
   714 
   715 *** Classical Reasoner ***
   716 
   717 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
   718 tactics that use classical reasoning to simplify a subgoal without
   719 splitting it into several subgoals;
   720 
   721 * Safe_tac: like safe_tac but uses the default claset;
   722 
   723 
   724 *** Simplifier ***
   725 
   726 * added simplification meta rules:
   727     (asm_)(full_)simplify: simpset -> thm -> thm;
   728 
   729 * simplifier.ML no longer part of Pure -- has to be loaded by object
   730 logics (again);
   731 
   732 * added prems argument to simplification procedures;
   733 
   734 * HOL, FOL, ZF: added infix function `addsplits':
   735   instead of `<simpset> setloop (split_tac <thms>)'
   736   you can simply write `<simpset> addsplits <thms>'
   737 
   738 
   739 *** Syntax ***
   740 
   741 * TYPE('a) syntax for type reflection terms;
   742 
   743 * no longer handles consts with name "" -- declare as 'syntax' instead;
   744 
   745 * pretty printer: changed order of mixfix annotation preference (again!);
   746 
   747 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
   748 
   749 
   750 *** HOL ***
   751 
   752 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
   753   with `addloop' of the simplifier to faciliate case splitting in premises.
   754 
   755 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
   756 
   757 * HOL/Auth: new protocol proofs including some for the Internet
   758   protocol TLS;
   759 
   760 * HOL/Map: new theory of `maps' a la VDM;
   761 
   762 * HOL/simplifier: simplification procedures nat_cancel_sums for
   763 cancelling out common nat summands from =, <, <= (in)equalities, or
   764 differences; simplification procedures nat_cancel_factor for
   765 cancelling common factor from =, <, <= (in)equalities over natural
   766 sums; nat_cancel contains both kinds of procedures, it is installed by
   767 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
   768 
   769 * HOL/simplifier: terms of the form
   770   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
   771   are rewritten to
   772   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
   773   and those of the form
   774   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
   775   are rewritten to
   776   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
   777 
   778 * HOL/datatype
   779   Each datatype `t' now comes with a theorem `split_t_case' of the form
   780 
   781   P(t_case f1 ... fn x) =
   782      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
   783         ...
   784        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
   785      )
   786 
   787   and a theorem `split_t_case_asm' of the form
   788 
   789   P(t_case f1 ... fn x) =
   790     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
   791         ...
   792        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
   793      )
   794   which can be added to a simpset via `addsplits'. The existing theorems
   795   expand_list_case and expand_option_case have been renamed to
   796   split_list_case and split_option_case.
   797 
   798 * HOL/Arithmetic:
   799   - `pred n' is automatically converted to `n-1'.
   800     Users are strongly encouraged not to use `pred' any longer,
   801     because it will disappear altogether at some point.
   802   - Users are strongly encouraged to write "0 < n" rather than
   803     "n ~= 0". Theorems and proof tools have been modified towards this
   804     `standard'.
   805 
   806 * HOL/Lists:
   807   the function "set_of_list" has been renamed "set" (and its theorems too);
   808   the function "nth" now takes its arguments in the reverse order and
   809   has acquired the infix notation "!" as in "xs!n".
   810 
   811 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
   812 
   813 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
   814   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
   815 
   816 * HOL/record: extensible records with schematic structural subtyping
   817 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
   818 still lacks various theorems and concrete record syntax;
   819 
   820 
   821 *** HOLCF ***
   822 
   823 * removed "axioms" and "generated by" sections;
   824 
   825 * replaced "ops" section by extended "consts" section, which is capable of
   826   handling the continuous function space "->" directly;
   827 
   828 * domain package:
   829   . proves theorems immediately and stores them in the theory,
   830   . creates hierachical name space,
   831   . now uses normal mixfix annotations (instead of cinfix...),
   832   . minor changes to some names and values (for consistency),
   833   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
   834   . separator between mutual domain defs: changed "," to "and",
   835   . improved handling of sort constraints;  now they have to
   836     appear on the left-hand side of the equations only;
   837 
   838 * fixed LAM <x,y,zs>.b syntax;
   839 
   840 * added extended adm_tac to simplifier in HOLCF -- can now discharge
   841 adm (%x. P (t x)), where P is chainfinite and t continuous;
   842 
   843 
   844 *** FOL and ZF ***
   845 
   846 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
   847   with `addloop' of the simplifier to faciliate case splitting in premises.
   848 
   849 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
   850 in HOL, they strip ALL and --> from proved theorems;
   851 
   852 
   853 
   854 New in Isabelle94-8 (May 1997)
   855 ------------------------------
   856 
   857 *** General Changes ***
   858 
   859 * new utilities to build / run / maintain Isabelle etc. (in parts
   860 still somewhat experimental); old Makefiles etc. still functional;
   861 
   862 * new 'Isabelle System Manual';
   863 
   864 * INSTALL text, together with ./configure and ./build scripts;
   865 
   866 * reimplemented type inference for greater efficiency, better error
   867 messages and clean internal interface;
   868 
   869 * prlim command for dealing with lots of subgoals (an easier way of
   870 setting goals_limit);
   871 
   872 
   873 *** Syntax ***
   874 
   875 * supports alternative (named) syntax tables (parser and pretty
   876 printer); internal interface is provided by add_modesyntax(_i);
   877 
   878 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
   879 be used in conjunction with the Isabelle symbol font; uses the
   880 "symbols" syntax table;
   881 
   882 * added token_translation interface (may translate name tokens in
   883 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
   884 the current print_mode); IMPORTANT: user print translation functions
   885 are responsible for marking newly introduced bounds
   886 (Syntax.mark_boundT);
   887 
   888 * token translations for modes "xterm" and "xterm_color" that display
   889 names in bold, underline etc. or colors (which requires a color
   890 version of xterm);
   891 
   892 * infixes may now be declared with names independent of their syntax;
   893 
   894 * added typed_print_translation (like print_translation, but may
   895 access type of constant);
   896 
   897 
   898 *** Classical Reasoner ***
   899 
   900 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
   901 some limitations.  Blast_tac...
   902   + ignores addss, addbefore, addafter; this restriction is intrinsic
   903   + ignores elimination rules that don't have the correct format
   904         (the conclusion MUST be a formula variable)
   905   + ignores types, which can make HOL proofs fail
   906   + rules must not require higher-order unification, e.g. apply_type in ZF
   907     [message "Function Var's argument not a bound variable" relates to this]
   908   + its proof strategy is more general but can actually be slower
   909 
   910 * substitution with equality assumptions no longer permutes other
   911 assumptions;
   912 
   913 * minor changes in semantics of addafter (now called addaltern); renamed
   914 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
   915 (and access functions for it);
   916 
   917 * improved combination of classical reasoner and simplifier:
   918   + functions for handling clasimpsets
   919   + improvement of addss: now the simplifier is called _after_ the
   920     safe steps.
   921   + safe variant of addss called addSss: uses safe simplifications
   922     _during_ the safe steps. It is more complete as it allows multiple
   923     instantiations of unknowns (e.g. with slow_tac).
   924 
   925 *** Simplifier ***
   926 
   927 * added interface for simplification procedures (functions that
   928 produce *proven* rewrite rules on the fly, depending on current
   929 redex);
   930 
   931 * ordering on terms as parameter (used for ordered rewriting);
   932 
   933 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
   934 
   935 * the solver is now split into a safe and an unsafe part.
   936 This should be invisible for the normal user, except that the
   937 functions setsolver and addsolver have been renamed to setSolver and
   938 addSolver; added safe_asm_full_simp_tac;
   939 
   940 
   941 *** HOL ***
   942 
   943 * a generic induction tactic `induct_tac' which works for all datatypes and
   944 also for type `nat';
   945 
   946 * a generic case distinction tactic `exhaust_tac' which works for all
   947 datatypes and also for type `nat';
   948 
   949 * each datatype comes with a function `size';
   950 
   951 * patterns in case expressions allow tuple patterns as arguments to
   952 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
   953 
   954 * primrec now also works with type nat;
   955 
   956 * recdef: a new declaration form, allows general recursive functions to be
   957 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
   958 
   959 * the constant for negation has been renamed from "not" to "Not" to
   960 harmonize with FOL, ZF, LK, etc.;
   961 
   962 * HOL/ex/LFilter theory of a corecursive "filter" functional for
   963 infinite lists;
   964 
   965 * HOL/Modelcheck demonstrates invocation of model checker oracle;
   966 
   967 * HOL/ex/Ring.thy declares cring_simp, which solves equational
   968 problems in commutative rings, using axiomatic type classes for + and *;
   969 
   970 * more examples in HOL/MiniML and HOL/Auth;
   971 
   972 * more default rewrite rules for quantifiers, union/intersection;
   973 
   974 * a new constant `arbitrary == @x.False';
   975 
   976 * HOLCF/IOA replaces old HOL/IOA;
   977 
   978 * HOLCF changes: derived all rules and arities
   979   + axiomatic type classes instead of classes
   980   + typedef instead of faking type definitions
   981   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
   982   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
   983   + eliminated the types void, one, tr
   984   + use unit lift and bool lift (with translations) instead of one and tr
   985   + eliminated blift from Lift3.thy (use Def instead of blift)
   986   all eliminated rules are derived as theorems --> no visible changes ;
   987 
   988 
   989 *** ZF ***
   990 
   991 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
   992 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
   993 as ZF_cs addSIs [equalityI];
   994 
   995 
   996 
   997 New in Isabelle94-7 (November 96)
   998 ---------------------------------
   999 
  1000 * allowing negative levels (as offsets) in prlev and choplev;
  1001 
  1002 * super-linear speedup for large simplifications;
  1003 
  1004 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  1005 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  1006 FAIL); can suppress it using the command Delsimps (ex_simps @
  1007 all_simps); De Morgan laws are also now included, by default;
  1008 
  1009 * improved printing of ==>  :  ~:
  1010 
  1011 * new object-logic "Sequents" adds linear logic, while replacing LK
  1012 and Modal (thanks to Sara Kalvala);
  1013 
  1014 * HOL/Auth: correctness proofs for authentication protocols;
  1015 
  1016 * HOL: new auto_tac combines rewriting and classical reasoning (many
  1017 examples on HOL/Auth);
  1018 
  1019 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  1020 the rewriter and classical reasoner simultaneously;
  1021 
  1022 * function uresult no longer returns theorems in "standard" format;
  1023 regain previous version by: val uresult = standard o uresult;
  1024 
  1025 
  1026 
  1027 New in Isabelle94-6
  1028 -------------------
  1029 
  1030 * oracles -- these establish an interface between Isabelle and trusted
  1031 external reasoners, which may deliver results as theorems;
  1032 
  1033 * proof objects (in particular record all uses of oracles);
  1034 
  1035 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  1036 
  1037 * "constdefs" section in theory files;
  1038 
  1039 * "primrec" section (HOL) no longer requires names;
  1040 
  1041 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  1042 
  1043 
  1044 
  1045 New in Isabelle94-5
  1046 -------------------
  1047 
  1048 * reduced space requirements;
  1049 
  1050 * automatic HTML generation from theories;
  1051 
  1052 * theory files no longer require "..." (quotes) around most types;
  1053 
  1054 * new examples, including two proofs of the Church-Rosser theorem;
  1055 
  1056 * non-curried (1994) version of HOL is no longer distributed;
  1057 
  1058 
  1059 
  1060 New in Isabelle94-4
  1061 -------------------
  1062 
  1063 * greatly reduced space requirements;
  1064 
  1065 * theory files (.thy) no longer require \...\ escapes at line breaks;
  1066 
  1067 * searchable theorem database (see the section "Retrieving theorems" on
  1068 page 8 of the Reference Manual);
  1069 
  1070 * new examples, including Grabczewski's monumental case study of the
  1071 Axiom of Choice;
  1072 
  1073 * The previous version of HOL renamed to Old_HOL;
  1074 
  1075 * The new version of HOL (previously called CHOL) uses a curried syntax
  1076 for functions.  Application looks like f a b instead of f(a,b);
  1077 
  1078 * Mutually recursive inductive definitions finally work in HOL;
  1079 
  1080 * In ZF, pattern-matching on tuples is now available in all abstractions and
  1081 translates to the operator "split";
  1082 
  1083 
  1084 
  1085 New in Isabelle94-3
  1086 -------------------
  1087 
  1088 * new infix operator, addss, allowing the classical reasoner to
  1089 perform simplification at each step of its search.  Example:
  1090         fast_tac (cs addss ss)
  1091 
  1092 * a new logic, CHOL, the same as HOL, but with a curried syntax
  1093 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  1094 look like (a,b) instead of <a,b>;
  1095 
  1096 * PLEASE NOTE: CHOL will eventually replace HOL!
  1097 
  1098 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  1099 It translates to the operator "split".  A new theory of integers is available;
  1100 
  1101 * In ZF, integer numerals now denote two's-complement binary integers.
  1102 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  1103 
  1104 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  1105 of the Axiom of Choice;
  1106 
  1107 
  1108 
  1109 New in Isabelle94-2
  1110 -------------------
  1111 
  1112 * Significantly faster resolution;
  1113 
  1114 * the different sections in a .thy file can now be mixed and repeated
  1115 freely;
  1116 
  1117 * Database of theorems for FOL, HOL and ZF.  New
  1118 commands including qed, qed_goal and bind_thm store theorems in the database.
  1119 
  1120 * Simple database queries: return a named theorem (get_thm) or all theorems of
  1121 a given theory (thms_of), or find out what theory a theorem was proved in
  1122 (theory_of_thm);
  1123 
  1124 * Bugs fixed in the inductive definition and datatype packages;
  1125 
  1126 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  1127 and HOL_dup_cs obsolete;
  1128 
  1129 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  1130 have been removed;
  1131 
  1132 * Simpler definition of function space in ZF;
  1133 
  1134 * new results about cardinal and ordinal arithmetic in ZF;
  1135 
  1136 * 'subtype' facility in HOL for introducing new types as subsets of existing
  1137 types;
  1138 
  1139 
  1140 $Id$