NEWS
author wenzelm
Mon May 22 16:03:43 2000 +0200 (2000-05-22)
changeset 8921 7c04c98132c4
parent 8887 c0c583ce0b0b
child 8925 f4599af94b83
permissions -rw-r--r--
* Pure: changed syntax of local blocks from {{ }} to { };
* Pure: syntax of sorts made inner, i.e. have to write "{a, b, c}";
     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: simplification of natural numbers is much changed; to partly
    11 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
    12 issue the following ML commands:
    13 
    14   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
    15   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
    16 
    17 * HOL: the constant for f``x is now "image" rather than "op ``";
    18 
    19 * HOL: the cartesian product is now "<*>" instead of "Times"; the
    20 lexicographic product is now "<*lex*>" instead of "**";
    21 
    22 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
    23 
    24 * HOL: simplification no longer dives into case-expressions
    25 
    26 * HOL: the recursion equations generated by 'recdef' are now called
    27 f.simps instead of f.rules;
    28 
    29 * HOL: theory Sexp now in HOL/Induct examples (used to be part of main
    30 HOL, but was unused); should better use HOL's datatype package anyway;
    31 
    32 * HOL/Real: "rabs" replaced by overloaded "abs" function;
    33 
    34 * HOL/ML: even fewer consts are declared as global (see theories Ord,
    35 Lfp, Gfp, WF); this only affects ML packages that refer to const names
    36 internally;
    37 
    38 * Isar: changed syntax of local blocks from {{ }} to { };
    39 
    40 * ML: PureThy.add_thms/add_axioms/add_defs return theorems as well;
    41 
    42 * LaTeX: several improvements of isabelle.sty;
    43 
    44 
    45 *** Document preparation ***
    46 
    47 * isatool mkdir provides easy setup of Isabelle session directories,
    48 including proper document sources;
    49 
    50 * generated LaTeX sources are now deleted after successful run
    51 (isatool document -c); may retain a copy somewhere else via -D option
    52 of isatool usedir;
    53 
    54 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
    55 style files, achieving self-contained LaTeX sources;
    56 
    57 * old-style theories now produce (crude) LaTeX output as well;
    58 
    59 
    60 *** Isar ***
    61 
    62 * Pure: local results and corresponding term bindings are now subject
    63 to Hindley-Milner polymorphism (similar to ML); this accommodates
    64 incremental type-inference nicely;
    65 
    66 * Pure: new 'obtain' language element supports generalized existence
    67 reasoning;
    68 
    69 * Pure: new calculational elements 'moreover' and 'ultimately' support
    70 plain accumulation of results, without applying any rules yet;
    71 
    72 * Pure: scalable support for case-analysis type proofs: new 'case'
    73 language element refers to local contexts symbolically, as produced by
    74 certain proof methods; internally, case names are attached to theorems
    75 as "tags";
    76 
    77 * Pure: changed syntax of local blocks from {{ }} to { };
    78 
    79 * Pure: syntax of sorts made inner, i.e. have to write "{a, b, c}"
    80 instead of {a, b, c};
    81 
    82 * Pure now provides its own version of intro/elim/dest attributes;
    83 useful for building new logics, but beware of confusion with the
    84 Provers/classical ones;
    85 
    86 * Provers: splitter support (via 'split' attribute and 'simp' method
    87 modifier); 'simp' method: 'only:' modifier removes loopers as well
    88 (including splits);
    89 
    90 * HOL: new proof method 'cases' and improved version of 'induct' now
    91 support named cases; major packages (inductive, datatype, primrec,
    92 recdef) support case names and properly name parameters;
    93 
    94 * HOL: removed 'case_split' thm binding, should use 'cases' proof
    95 method anyway;
    96 
    97 * names of theorems etc. may be natural numbers as well;
    98 
    99 * Provers: intro/elim/dest attributes: changed ! / !! flags to ? / ??;
   100 
   101 * 'pr' command: optional goals_limit argument; no longer prints theory
   102 contexts, but only proof states;
   103 
   104 * diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
   105 additional print modes to be specified; e.g. "pr(latex)" will print
   106 proof state according to the Isabelle LaTeX style;
   107 
   108 * improved support for emulating tactic scripts, including proof
   109 methods 'tactic', 'res_inst_tac' etc., 'subgoal_tac', and 'case_tac' /
   110 'induct_tac' (for HOL datatypes);
   111 
   112 * simplified (more robust) goal selection of proof methods: 1st goal,
   113 all goals, or explicit goal specifier (tactic emulation); thus 'proof
   114 method scripts' have to be in depth-first order;
   115 
   116 * tuned 'let' syntax: replace 'as' keyword by 'and';
   117 
   118 * theory command 'hide' removes declarations from class/type/const
   119 name spaces;
   120 
   121 
   122 *** HOL ***
   123 
   124 * HOL/Algebra: new theory of rings and univariate polynomials, by
   125 Clemens Ballarin;
   126 
   127 * HOL/record: fixed select-update simplification procedure to handle
   128 extended records as well; admit "r" as field name;
   129 
   130 * HOL/ex: new theory Factorization proving the Fundamental Theorem of
   131 Arithmetic, by Thomas M Rasmussen;
   132 
   133 * HOL/ex/Multiquote: multiple nested quotations and anti-quotations --
   134 basically a generalized version of de-Bruijn representation; very
   135 useful in avoiding lifting all operations;
   136 
   137 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   138 
   139 * greatly improved simplification involving numerals of type nat & int, e.g.
   140    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
   141    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
   142   two terms #m*u and #n*u are replaced by #(m+n)*u
   143     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
   144   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
   145     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
   146 
   147 * HOL: new version of "case_tac" subsumes both boolean case split and
   148 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
   149 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
   150 
   151 * HOL: simplification no longer dives into case-expressions: only the
   152 selector expression is simplified, but not the remaining arms. To
   153 enable full simplification of case-expressions for datatype t, you
   154 need to remove t.weak_case_cong from the simpset, either permanently
   155 (Delcongs[thm"t.weak_case_cong"];) or locally (delcongs [...]).
   156 
   157 * HOL/recdef: the recursion equations generated by 'recdef' for
   158 function 'f' are now called f.simps instead of f.rules; if all
   159 termination conditions are proved automatically, these simplification
   160 rules are added to the simpset, as in primrec; rules may be named
   161 individually as well, resulting in a separate list of theorems for
   162 each equation;
   163 
   164 * HOL: theorems impI, allI, ballI bound as "strip";
   165 
   166 * theory Sexp now in HOL/Induct examples (used to be part of main HOL,
   167 but was unused);
   168 
   169 * fewer consts declared as global (e.g. have to refer to "Lfp.lfp"
   170 instead of "lfp" internally; affects ML packages only);
   171 
   172 
   173 *** General ***
   174 
   175 * improved name spaces: ambiguous output is qualified; support for
   176 hiding of names;
   177 
   178 * compression of ML heaps images may now be controlled via -c option
   179 of isabelle and isatool usedir (currently only observed by Poly/ML);
   180 
   181 * ML: new combinators |>> and |>>> for incremental transformations
   182 with secondary results (e.g. certain theory extensions):
   183 
   184 
   185 
   186 New in Isabelle99 (October 1999)
   187 --------------------------------
   188 
   189 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   190 
   191 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
   192 are no longer simplified.  (This allows the simplifier to unfold recursive
   193 functional programs.)  To restore the old behaviour, declare
   194 
   195     Delcongs [if_weak_cong];
   196 
   197 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
   198 complement;
   199 
   200 * HOL: the predicate "inj" is now defined by translation to "inj_on";
   201 
   202 * HOL/datatype: mutual_induct_tac no longer exists --
   203   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
   204 
   205 * HOL/typedef: fixed type inference for representing set; type
   206 arguments now have to occur explicitly on the rhs as type constraints;
   207 
   208 * ZF: The con_defs part of an inductive definition may no longer refer
   209 to constants declared in the same theory;
   210 
   211 * HOL, ZF: the function mk_cases, generated by the inductive
   212 definition package, has lost an argument.  To simplify its result, it
   213 uses the default simpset instead of a supplied list of theorems.
   214 
   215 * HOL/List: the constructors of type list are now Nil and Cons;
   216 
   217 * Simplifier: the type of the infix ML functions
   218         setSSolver addSSolver setSolver addSolver
   219 is now  simpset * solver -> simpset  where `solver' is a new abstract type
   220 for packaging solvers. A solver is created via
   221         mk_solver: string -> (thm list -> int -> tactic) -> solver
   222 where the string argument is only a comment.
   223 
   224 
   225 *** Proof tools ***
   226 
   227 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
   228 decision procedure for linear arithmetic. Currently it is used for
   229 types `nat', `int', and `real' in HOL (see below); it can, should and
   230 will be instantiated for other types and logics as well.
   231 
   232 * The simplifier now accepts rewrite rules with flexible heads, eg
   233      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
   234   They are applied like any rule with a non-pattern lhs, i.e. by first-order
   235   matching.
   236 
   237 
   238 *** General ***
   239 
   240 * New Isabelle/Isar subsystem provides an alternative to traditional
   241 tactical theorem proving; together with the ProofGeneral/isar user
   242 interface it offers an interactive environment for developing human
   243 readable proof documents (Isar == Intelligible semi-automated
   244 reasoning); for further information see isatool doc isar-ref,
   245 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
   246 
   247 * improved presentation of theories: better HTML markup (including
   248 colors), graph views in several sizes; isatool usedir now provides a
   249 proper interface for user theories (via -P option); actual document
   250 preparation based on (PDF)LaTeX is available as well (for new-style
   251 theories only); see isatool doc system for more information;
   252 
   253 * native support for Proof General, both for classic Isabelle and
   254 Isabelle/Isar;
   255 
   256 * ML function thm_deps visualizes dependencies of theorems and lemmas,
   257 using the graph browser tool;
   258 
   259 * Isabelle manuals now also available as PDF;
   260 
   261 * theory loader rewritten from scratch (may not be fully
   262 bug-compatible); old loadpath variable has been replaced by show_path,
   263 add_path, del_path, reset_path functions; new operations such as
   264 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
   265 isatool doc ref);
   266 
   267 * improved isatool install: option -k creates KDE application icon,
   268 option -p DIR installs standalone binaries;
   269 
   270 * added ML_PLATFORM setting (useful for cross-platform installations);
   271 more robust handling of platform specific ML images for SML/NJ;
   272 
   273 * the settings environment is now statically scoped, i.e. it is never
   274 created again in sub-processes invoked from isabelle, isatool, or
   275 Isabelle;
   276 
   277 * path element specification '~~' refers to '$ISABELLE_HOME';
   278 
   279 * in locales, the "assumes" and "defines" parts may be omitted if
   280 empty;
   281 
   282 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
   283 long arrows);
   284 
   285 * new print_mode "HTML";
   286 
   287 * new flag show_tags controls display of tags of theorems (which are
   288 basically just comments that may be attached by some tools);
   289 
   290 * Isamode 2.6 requires patch to accomodate change of Isabelle font
   291 mode and goal output format:
   292 
   293 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
   294 244c244
   295 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
   296 ---
   297 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
   298 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
   299 181c181
   300 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
   301 ---
   302 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
   303 
   304 * function bind_thms stores lists of theorems (cf. bind_thm);
   305 
   306 * new shorthand tactics ftac, eatac, datac, fatac;
   307 
   308 * qed (and friends) now accept "" as result name; in that case the
   309 theorem is not stored, but proper checks and presentation of the
   310 result still apply;
   311 
   312 * theorem database now also indexes constants "Trueprop", "all",
   313 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
   314 
   315 
   316 *** HOL ***
   317 
   318 ** HOL arithmetic **
   319 
   320 * There are now decision procedures for linear arithmetic over nat and
   321 int:
   322 
   323 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
   324 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
   325 are treated as atomic; subformulae not involving type `nat' or `int'
   326 are ignored; quantified subformulae are ignored unless they are
   327 positive universal or negative existential. The tactic has to be
   328 invoked by hand and can be a little bit slow. In particular, the
   329 running time is exponential in the number of occurrences of `min' and
   330 `max', and `-' on `nat'.
   331 
   332 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
   333 (negated) (in)equalities among the premises and the conclusion into
   334 account (i.e. no compound formulae) and does not know about `min' and
   335 `max', and `-' on `nat'. It is fast and is used automatically by the
   336 simplifier.
   337 
   338 NB: At the moment, these decision procedures do not cope with mixed
   339 nat/int formulae where the two parts interact, such as `m < n ==>
   340 int(m) < int(n)'.
   341 
   342 * HOL/Numeral provides a generic theory of numerals (encoded
   343 efficiently as bit strings); setup for types nat/int/real is in place;
   344 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
   345 int, existing theories and proof scripts may require a few additional
   346 type constraints;
   347 
   348 * integer division and remainder can now be performed on constant
   349 arguments;
   350 
   351 * many properties of integer multiplication, division and remainder
   352 are now available;
   353 
   354 * An interface to the Stanford Validity Checker (SVC) is available through the
   355 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
   356 are proved automatically.  SVC must be installed separately, and its results
   357 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
   358 invocation of the underlying oracle).  For SVC see
   359   http://verify.stanford.edu/SVC
   360 
   361 * IsaMakefile: the HOL-Real target now builds an actual image;
   362 
   363 
   364 ** HOL misc **
   365 
   366 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
   367 (in Isabelle/Isar) -- by Gertrud Bauer;
   368 
   369 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
   370 analysis for assembly languages with subtypes;
   371 
   372 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
   373 -- avoids syntactic ambiguities and treats state, transition, and
   374 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
   375 changed syntax and (many) tactics;
   376 
   377 * HOL/inductive: Now also handles more general introduction rules such
   378   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
   379   theorems are now maintained within the theory (maintained via the
   380   "mono" attribute);
   381 
   382 * HOL/datatype: Now also handles arbitrarily branching datatypes
   383   (using function types) such as
   384 
   385   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
   386 
   387 * HOL/record: record_simproc (part of the default simpset) takes care
   388 of selectors applied to updated records; record_split_tac is no longer
   389 part of the default claset; update_defs may now be removed from the
   390 simpset in many cases; COMPATIBILITY: old behavior achieved by
   391 
   392   claset_ref () := claset() addSWrapper record_split_wrapper;
   393   Delsimprocs [record_simproc]
   394 
   395 * HOL/typedef: fixed type inference for representing set; type
   396 arguments now have to occur explicitly on the rhs as type constraints;
   397 
   398 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
   399 names rather than an ML expression;
   400 
   401 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
   402 supplied later.  Program schemes can be defined, such as
   403     "While B C s = (if B s then While B C (C s) else s)"
   404 where the well-founded relation can be chosen after B and C have been given.
   405 
   406 * HOL/List: the constructors of type list are now Nil and Cons;
   407 INCOMPATIBILITY: while [] and infix # syntax is still there, of
   408 course, ML tools referring to List.list.op # etc. have to be adapted;
   409 
   410 * HOL_quantifiers flag superseded by "HOL" print mode, which is
   411 disabled by default; run isabelle with option -m HOL to get back to
   412 the original Gordon/HOL-style output;
   413 
   414 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
   415 ALL x<=y. P, EX x<y. P, EX x<=y. P;
   416 
   417 * HOL basic syntax simplified (more orthogonal): all variants of
   418 All/Ex now support plain / symbolic / HOL notation; plain syntax for
   419 Eps operator is provided as well: "SOME x. P[x]";
   420 
   421 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
   422 
   423 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
   424 thus available for user theories;
   425 
   426 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
   427 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
   428 time;
   429 
   430 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
   431 several times and then mp;
   432 
   433 
   434 *** LK ***
   435 
   436 * the notation <<...>> is now available as a notation for sequences of
   437 formulas;
   438 
   439 * the simplifier is now installed
   440 
   441 * the axiom system has been generalized (thanks to Soren Heilmann)
   442 
   443 * the classical reasoner now has a default rule database
   444 
   445 
   446 *** ZF ***
   447 
   448 * new primrec section allows primitive recursive functions to be given
   449 directly (as in HOL) over datatypes and the natural numbers;
   450 
   451 * new tactics induct_tac and exhaust_tac for induction (or case
   452 analysis) over datatypes and the natural numbers;
   453 
   454 * the datatype declaration of type T now defines the recursor T_rec;
   455 
   456 * simplification automatically does freeness reasoning for datatype
   457 constructors;
   458 
   459 * automatic type-inference, with AddTCs command to insert new
   460 type-checking rules;
   461 
   462 * datatype introduction rules are now added as Safe Introduction rules
   463 to the claset;
   464 
   465 * the syntax "if P then x else y" is now available in addition to
   466 if(P,x,y);
   467 
   468 
   469 *** Internal programming interfaces ***
   470 
   471 * tuned simplifier trace output; new flag debug_simp;
   472 
   473 * structures Vartab / Termtab (instances of TableFun) offer efficient
   474 tables indexed by indexname_ord / term_ord (compatible with aconv);
   475 
   476 * AxClass.axclass_tac lost the theory argument;
   477 
   478 * tuned current_goals_markers semantics: begin / end goal avoids
   479 printing empty lines;
   480 
   481 * removed prs and prs_fn hook, which was broken because it did not
   482 include \n in its semantics, forcing writeln to add one
   483 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
   484 string -> unit if you really want to output text without newline;
   485 
   486 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
   487 plain output, interface builders may have to enable 'isabelle_font'
   488 mode to get Isabelle font glyphs as before;
   489 
   490 * refined token_translation interface; INCOMPATIBILITY: output length
   491 now of type real instead of int;
   492 
   493 * theory loader actions may be traced via new ThyInfo.add_hook
   494 interface (see src/Pure/Thy/thy_info.ML); example application: keep
   495 your own database of information attached to *whole* theories -- as
   496 opposed to intra-theory data slots offered via TheoryDataFun;
   497 
   498 * proper handling of dangling sort hypotheses (at last!);
   499 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
   500 extra sort hypotheses that can be witnessed from the type signature;
   501 the force_strip_shyps flag is gone, any remaining shyps are simply
   502 left in the theorem (with a warning issued by strip_shyps_warning);
   503 
   504 
   505 
   506 New in Isabelle98-1 (October 1998)
   507 ----------------------------------
   508 
   509 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   510 
   511 * several changes of automated proof tools;
   512 
   513 * HOL: major changes to the inductive and datatype packages, including
   514 some minor incompatibilities of theory syntax;
   515 
   516 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
   517 called `inj_on';
   518 
   519 * HOL: removed duplicate thms in Arith:
   520   less_imp_add_less  should be replaced by  trans_less_add1
   521   le_imp_add_le      should be replaced by  trans_le_add1
   522 
   523 * HOL: unary minus is now overloaded (new type constraints may be
   524 required);
   525 
   526 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
   527 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
   528 now taken as an integer constant.
   529 
   530 * Pure: ML function 'theory_of' renamed to 'theory';
   531 
   532 
   533 *** Proof tools ***
   534 
   535 * Simplifier:
   536   1. Asm_full_simp_tac is now more aggressive.
   537      1. It will sometimes reorient premises if that increases their power to
   538         simplify.
   539      2. It does no longer proceed strictly from left to right but may also
   540         rotate premises to achieve further simplification.
   541      For compatibility reasons there is now Asm_lr_simp_tac which is like the
   542      old Asm_full_simp_tac in that it does not rotate premises.
   543   2. The simplifier now knows a little bit about nat-arithmetic.
   544 
   545 * Classical reasoner: wrapper mechanism for the classical reasoner now
   546 allows for selected deletion of wrappers, by introduction of names for
   547 wrapper functionals.  This implies that addbefore, addSbefore,
   548 addaltern, and addSaltern now take a pair (name, tactic) as argument,
   549 and that adding two tactics with the same name overwrites the first
   550 one (emitting a warning).
   551   type wrapper = (int -> tactic) -> (int -> tactic)
   552   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
   553   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
   554   delWrapper, delSWrapper: claset *  string            -> claset
   555   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
   556 
   557 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
   558 semantics; addbefore now affects only the unsafe part of step_tac
   559 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
   560 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
   561 by Force_tac;
   562 
   563 * Classical reasoner: setwrapper to setWrapper and compwrapper to
   564 compWrapper; added safe wrapper (and access functions for it);
   565 
   566 * HOL/split_all_tac is now much faster and fails if there is nothing
   567 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
   568 and the names of the automatically generated variables have changed.
   569 split_all_tac has moved within claset() from unsafe wrappers to safe
   570 wrappers, which means that !!-bound variables are split much more
   571 aggressively, and safe_tac and clarify_tac now split such variables.
   572 If this splitting is not appropriate, use delSWrapper "split_all_tac".
   573 Note: the same holds for record_split_tac, which does the job of
   574 split_all_tac for record fields.
   575 
   576 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
   577 permanently to the default simpset using Addsplits just like
   578 Addsimps. They can be removed via Delsplits just like
   579 Delsimps. Lower-case versions are also available.
   580 
   581 * HOL/Simplifier: The rule split_if is now part of the default
   582 simpset. This means that the simplifier will eliminate all occurrences
   583 of if-then-else in the conclusion of a goal. To prevent this, you can
   584 either remove split_if completely from the default simpset by
   585 `Delsplits [split_if]' or remove it in a specific call of the
   586 simplifier using `... delsplits [split_if]'.  You can also add/delete
   587 other case splitting rules to/from the default simpset: every datatype
   588 generates suitable rules `split_t_case' and `split_t_case_asm' (where
   589 t is the name of the datatype).
   590 
   591 * Classical reasoner / Simplifier combination: new force_tac (and
   592 derivatives Force_tac, force) combines rewriting and classical
   593 reasoning (and whatever other tools) similarly to auto_tac, but is
   594 aimed to solve the given subgoal completely.
   595 
   596 
   597 *** General ***
   598 
   599 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
   600 and `goalw': the theory is no longer needed as an explicit argument -
   601 the current theory context is used; assumptions are no longer returned
   602 at the ML-level unless one of them starts with ==> or !!; it is
   603 recommended to convert to these new commands using isatool fixgoal
   604 (backup your sources first!);
   605 
   606 * new top-level commands 'thm' and 'thms' for retrieving theorems from
   607 the current theory context, and 'theory' to lookup stored theories;
   608 
   609 * new theory section 'locale' for declaring constants, assumptions and
   610 definitions that have local scope;
   611 
   612 * new theory section 'nonterminals' for purely syntactic types;
   613 
   614 * new theory section 'setup' for generic ML setup functions
   615 (e.g. package initialization);
   616 
   617 * the distribution now includes Isabelle icons: see
   618 lib/logo/isabelle-{small,tiny}.xpm;
   619 
   620 * isatool install - install binaries with absolute references to
   621 ISABELLE_HOME/bin;
   622 
   623 * isatool logo -- create instances of the Isabelle logo (as EPS);
   624 
   625 * print mode 'emacs' reserved for Isamode;
   626 
   627 * support multiple print (ast) translations per constant name;
   628 
   629 * theorems involving oracles are now printed with a suffixed [!];
   630 
   631 
   632 *** HOL ***
   633 
   634 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
   635 
   636 * HOL/inductive package reorganized and improved: now supports mutual
   637 definitions such as
   638 
   639   inductive EVEN ODD
   640     intrs
   641       null "0 : EVEN"
   642       oddI "n : EVEN ==> Suc n : ODD"
   643       evenI "n : ODD ==> Suc n : EVEN"
   644 
   645 new theorem list "elims" contains an elimination rule for each of the
   646 recursive sets; inductive definitions now handle disjunctive premises
   647 correctly (also ZF);
   648 
   649 INCOMPATIBILITIES: requires Inductive as an ancestor; component
   650 "mutual_induct" no longer exists - the induction rule is always
   651 contained in "induct";
   652 
   653 
   654 * HOL/datatype package re-implemented and greatly improved: now
   655 supports mutually recursive datatypes such as
   656 
   657   datatype
   658     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
   659             | SUM ('a aexp) ('a aexp)
   660             | DIFF ('a aexp) ('a aexp)
   661             | NUM 'a
   662   and
   663     'a bexp = LESS ('a aexp) ('a aexp)
   664             | AND ('a bexp) ('a bexp)
   665             | OR ('a bexp) ('a bexp)
   666 
   667 as well as indirectly recursive datatypes such as
   668 
   669   datatype
   670     ('a, 'b) term = Var 'a
   671                   | App 'b ((('a, 'b) term) list)
   672 
   673 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
   674 induction on mutually / indirectly recursive datatypes.
   675 
   676 Primrec equations are now stored in theory and can be accessed via
   677 <function_name>.simps.
   678 
   679 INCOMPATIBILITIES:
   680 
   681   - Theories using datatypes must now have theory Datatype as an
   682     ancestor.
   683   - The specific <typename>.induct_tac no longer exists - use the
   684     generic induct_tac instead.
   685   - natE has been renamed to nat.exhaust - use exhaust_tac
   686     instead of res_inst_tac ... natE. Note that the variable
   687     names in nat.exhaust differ from the names in natE, this
   688     may cause some "fragile" proofs to fail.
   689   - The theorems split_<typename>_case and split_<typename>_case_asm
   690     have been renamed to <typename>.split and <typename>.split_asm.
   691   - Since default sorts of type variables are now handled correctly,
   692     some datatype definitions may have to be annotated with explicit
   693     sort constraints.
   694   - Primrec definitions no longer require function name and type
   695     of recursive argument.
   696 
   697 Consider using isatool fixdatatype to adapt your theories and proof
   698 scripts to the new package (backup your sources first!).
   699 
   700 
   701 * HOL/record package: considerably improved implementation; now
   702 includes concrete syntax for record types, terms, updates; theorems
   703 for surjective pairing and splitting !!-bound record variables; proof
   704 support is as follows:
   705 
   706   1) standard conversions (selectors or updates applied to record
   707 constructor terms) are part of the standard simpset;
   708 
   709   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
   710 made part of standard simpset and claset via addIffs;
   711 
   712   3) a tactic for record field splitting (record_split_tac) is part of
   713 the standard claset (addSWrapper);
   714 
   715 To get a better idea about these rules you may retrieve them via
   716 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
   717 the name of your record type.
   718 
   719 The split tactic 3) conceptually simplifies by the following rule:
   720 
   721   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
   722 
   723 Thus any record variable that is bound by meta-all will automatically
   724 blow up into some record constructor term, consequently the
   725 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
   726 solve record problems automatically.
   727 
   728 
   729 * reorganized the main HOL image: HOL/Integ and String loaded by
   730 default; theory Main includes everything;
   731 
   732 * automatic simplification of integer sums and comparisons, using cancellation;
   733 
   734 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
   735 
   736 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
   737 
   738 * many new identities for unions, intersections, set difference, etc.;
   739 
   740 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
   741 called split_if, split_split, split_sum_case and split_nat_case (to go
   742 with add/delsplits);
   743 
   744 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
   745 (?x::unit) = (); this is made part of the default simpset, which COULD
   746 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
   747 'Delsimprocs [unit_eq_proc];' as last resort); also note that
   748 unit_abs_eta_conv is added in order to counter the effect of
   749 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
   750 %u.f();
   751 
   752 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
   753 makes more sense);
   754 
   755 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   756   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   757   disjointness reasoning but breaking a few old proofs.
   758 
   759 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
   760 to 'converse' from 'inverse' (for compatibility with ZF and some
   761 literature);
   762 
   763 * HOL/recdef can now declare non-recursive functions, with {} supplied as
   764 the well-founded relation;
   765 
   766 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
   767     Compl A.  The "Compl" syntax remains available as input syntax for this
   768     release ONLY.
   769 
   770 * HOL/Update: new theory of function updates:
   771     f(a:=b) == %x. if x=a then b else f x
   772 may also be iterated as in f(a:=b,c:=d,...);
   773 
   774 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
   775 
   776 * HOL/List:
   777   - new function list_update written xs[i:=v] that updates the i-th
   778     list position. May also be iterated as in xs[i:=a,j:=b,...].
   779   - new function `upt' written [i..j(] which generates the list
   780     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
   781     bound write [i..j], which is a shorthand for [i..j+1(].
   782   - new lexicographic orderings and corresponding wellfoundedness theorems.
   783 
   784 * HOL/Arith:
   785   - removed 'pred' (predecessor) function;
   786   - generalized some theorems about n-1;
   787   - many new laws about "div" and "mod";
   788   - new laws about greatest common divisors (see theory ex/Primes);
   789 
   790 * HOL/Relation: renamed the relational operator r^-1 "converse"
   791 instead of "inverse";
   792 
   793 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
   794   of the multiset ordering;
   795 
   796 * directory HOL/Real: a construction of the reals using Dedekind cuts
   797   (not included by default);
   798 
   799 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
   800 
   801 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
   802   programs, i.e. different program variables may have different types.
   803 
   804 * calling (stac rew i) now fails if "rew" has no effect on the goal
   805   [previously, this check worked only if the rewrite rule was unconditional]
   806   Now rew can involve either definitions or equalities (either == or =).
   807 
   808 
   809 *** ZF ***
   810 
   811 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
   812   only the theorems proved on ZF.ML;
   813 
   814 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   815   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   816   disjointness reasoning but breaking a few old proofs.
   817 
   818 * ZF/Update: new theory of function updates
   819     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
   820   may also be iterated as in f(a:=b,c:=d,...);
   821 
   822 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
   823 
   824 * calling (stac rew i) now fails if "rew" has no effect on the goal
   825   [previously, this check worked only if the rewrite rule was unconditional]
   826   Now rew can involve either definitions or equalities (either == or =).
   827 
   828 * case_tac provided for compatibility with HOL
   829     (like the old excluded_middle_tac, but with subgoals swapped)
   830 
   831 
   832 *** Internal programming interfaces ***
   833 
   834 * Pure: several new basic modules made available for general use, see
   835 also src/Pure/README;
   836 
   837 * improved the theory data mechanism to support encapsulation (data
   838 kind name replaced by private Object.kind, acting as authorization
   839 key); new type-safe user interface via functor TheoryDataFun; generic
   840 print_data function becomes basically useless;
   841 
   842 * removed global_names compatibility flag -- all theory declarations
   843 are qualified by default;
   844 
   845 * module Pure/Syntax now offers quote / antiquote translation
   846 functions (useful for Hoare logic etc. with implicit dependencies);
   847 see HOL/ex/Antiquote for an example use;
   848 
   849 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
   850 cterm -> thm;
   851 
   852 * new tactical CHANGED_GOAL for checking that a tactic modifies a
   853 subgoal;
   854 
   855 * Display.print_goals function moved to Locale.print_goals;
   856 
   857 * standard print function for goals supports current_goals_markers
   858 variable for marking begin of proof, end of proof, start of goal; the
   859 default is ("", "", ""); setting current_goals_markers := ("<proof>",
   860 "</proof>", "<goal>") causes SGML like tagged proof state printing,
   861 for example;
   862 
   863 
   864 
   865 New in Isabelle98 (January 1998)
   866 --------------------------------
   867 
   868 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   869 
   870 * changed lexical syntax of terms / types: dots made part of long
   871 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
   872 
   873 * simpset (and claset) reference variable replaced by functions
   874 simpset / simpset_ref;
   875 
   876 * no longer supports theory aliases (via merge) and non-trivial
   877 implicit merge of thms' signatures;
   878 
   879 * most internal names of constants changed due to qualified names;
   880 
   881 * changed Pure/Sequence interface (see Pure/seq.ML);
   882 
   883 
   884 *** General Changes ***
   885 
   886 * hierachically structured name spaces (for consts, types, axms, thms
   887 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
   888 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
   889 isatool fixdots ensures space after dots (e.g. "%x. x"); set
   890 long_names for fully qualified output names; NOTE: ML programs
   891 (special tactics, packages etc.) referring to internal names may have
   892 to be adapted to cope with fully qualified names; in case of severe
   893 backward campatibility problems try setting 'global_names' at compile
   894 time to have enrything declared within a flat name space; one may also
   895 fine tune name declarations in theories via the 'global' and 'local'
   896 section;
   897 
   898 * reimplemented the implicit simpset and claset using the new anytype
   899 data filed in signatures; references simpset:simpset ref etc. are
   900 replaced by functions simpset:unit->simpset and
   901 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
   902 to patch your ML files accordingly;
   903 
   904 * HTML output now includes theory graph data for display with Java
   905 applet or isatool browser; data generated automatically via isatool
   906 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
   907 
   908 * defs may now be conditional; improved rewrite_goals_tac to handle
   909 conditional equations;
   910 
   911 * defs now admits additional type arguments, using TYPE('a) syntax;
   912 
   913 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
   914 creates a new theory node; implicit merge of thms' signatures is
   915 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
   916 transfer:theory->thm->thm in (rare) cases;
   917 
   918 * improved handling of draft signatures / theories; draft thms (and
   919 ctyps, cterms) are automatically promoted to real ones;
   920 
   921 * slightly changed interfaces for oracles: admit many per theory, named
   922 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
   923 
   924 * print_goals: optional output of const types (set show_consts and
   925 show_types);
   926 
   927 * improved output of warnings (###) and errors (***);
   928 
   929 * subgoal_tac displays a warning if the new subgoal has type variables;
   930 
   931 * removed old README and Makefiles;
   932 
   933 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
   934 
   935 * removed obsolete init_pps and init_database;
   936 
   937 * deleted the obsolete tactical STATE, which was declared by
   938     fun STATE tacfun st = tacfun st st;
   939 
   940 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
   941 (which abbreviates $HOME);
   942 
   943 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
   944 use isatool fixseq to adapt your ML programs (this works for fully
   945 qualified references to the Sequence structure only!);
   946 
   947 * use_thy no longer requires writable current directory; it always
   948 reloads .ML *and* .thy file, if either one is out of date;
   949 
   950 
   951 *** Classical Reasoner ***
   952 
   953 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
   954 tactics that use classical reasoning to simplify a subgoal without
   955 splitting it into several subgoals;
   956 
   957 * Safe_tac: like safe_tac but uses the default claset;
   958 
   959 
   960 *** Simplifier ***
   961 
   962 * added simplification meta rules:
   963     (asm_)(full_)simplify: simpset -> thm -> thm;
   964 
   965 * simplifier.ML no longer part of Pure -- has to be loaded by object
   966 logics (again);
   967 
   968 * added prems argument to simplification procedures;
   969 
   970 * HOL, FOL, ZF: added infix function `addsplits':
   971   instead of `<simpset> setloop (split_tac <thms>)'
   972   you can simply write `<simpset> addsplits <thms>'
   973 
   974 
   975 *** Syntax ***
   976 
   977 * TYPE('a) syntax for type reflection terms;
   978 
   979 * no longer handles consts with name "" -- declare as 'syntax' instead;
   980 
   981 * pretty printer: changed order of mixfix annotation preference (again!);
   982 
   983 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
   984 
   985 
   986 *** HOL ***
   987 
   988 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
   989   with `addloop' of the simplifier to faciliate case splitting in premises.
   990 
   991 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
   992 
   993 * HOL/Auth: new protocol proofs including some for the Internet
   994   protocol TLS;
   995 
   996 * HOL/Map: new theory of `maps' a la VDM;
   997 
   998 * HOL/simplifier: simplification procedures nat_cancel_sums for
   999 cancelling out common nat summands from =, <, <= (in)equalities, or
  1000 differences; simplification procedures nat_cancel_factor for
  1001 cancelling common factor from =, <, <= (in)equalities over natural
  1002 sums; nat_cancel contains both kinds of procedures, it is installed by
  1003 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  1004 
  1005 * HOL/simplifier: terms of the form
  1006   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  1007   are rewritten to
  1008   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  1009   and those of the form
  1010   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  1011   are rewritten to
  1012   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  1013 
  1014 * HOL/datatype
  1015   Each datatype `t' now comes with a theorem `split_t_case' of the form
  1016 
  1017   P(t_case f1 ... fn x) =
  1018      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  1019         ...
  1020        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  1021      )
  1022 
  1023   and a theorem `split_t_case_asm' of the form
  1024 
  1025   P(t_case f1 ... fn x) =
  1026     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  1027         ...
  1028        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  1029      )
  1030   which can be added to a simpset via `addsplits'. The existing theorems
  1031   expand_list_case and expand_option_case have been renamed to
  1032   split_list_case and split_option_case.
  1033 
  1034 * HOL/Arithmetic:
  1035   - `pred n' is automatically converted to `n-1'.
  1036     Users are strongly encouraged not to use `pred' any longer,
  1037     because it will disappear altogether at some point.
  1038   - Users are strongly encouraged to write "0 < n" rather than
  1039     "n ~= 0". Theorems and proof tools have been modified towards this
  1040     `standard'.
  1041 
  1042 * HOL/Lists:
  1043   the function "set_of_list" has been renamed "set" (and its theorems too);
  1044   the function "nth" now takes its arguments in the reverse order and
  1045   has acquired the infix notation "!" as in "xs!n".
  1046 
  1047 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  1048 
  1049 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  1050   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  1051 
  1052 * HOL/record: extensible records with schematic structural subtyping
  1053 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  1054 still lacks various theorems and concrete record syntax;
  1055 
  1056 
  1057 *** HOLCF ***
  1058 
  1059 * removed "axioms" and "generated by" sections;
  1060 
  1061 * replaced "ops" section by extended "consts" section, which is capable of
  1062   handling the continuous function space "->" directly;
  1063 
  1064 * domain package:
  1065   . proves theorems immediately and stores them in the theory,
  1066   . creates hierachical name space,
  1067   . now uses normal mixfix annotations (instead of cinfix...),
  1068   . minor changes to some names and values (for consistency),
  1069   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  1070   . separator between mutual domain defs: changed "," to "and",
  1071   . improved handling of sort constraints;  now they have to
  1072     appear on the left-hand side of the equations only;
  1073 
  1074 * fixed LAM <x,y,zs>.b syntax;
  1075 
  1076 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  1077 adm (%x. P (t x)), where P is chainfinite and t continuous;
  1078 
  1079 
  1080 *** FOL and ZF ***
  1081 
  1082 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1083   with `addloop' of the simplifier to faciliate case splitting in premises.
  1084 
  1085 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  1086 in HOL, they strip ALL and --> from proved theorems;
  1087 
  1088 
  1089 
  1090 New in Isabelle94-8 (May 1997)
  1091 ------------------------------
  1092 
  1093 *** General Changes ***
  1094 
  1095 * new utilities to build / run / maintain Isabelle etc. (in parts
  1096 still somewhat experimental); old Makefiles etc. still functional;
  1097 
  1098 * new 'Isabelle System Manual';
  1099 
  1100 * INSTALL text, together with ./configure and ./build scripts;
  1101 
  1102 * reimplemented type inference for greater efficiency, better error
  1103 messages and clean internal interface;
  1104 
  1105 * prlim command for dealing with lots of subgoals (an easier way of
  1106 setting goals_limit);
  1107 
  1108 
  1109 *** Syntax ***
  1110 
  1111 * supports alternative (named) syntax tables (parser and pretty
  1112 printer); internal interface is provided by add_modesyntax(_i);
  1113 
  1114 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  1115 be used in conjunction with the Isabelle symbol font; uses the
  1116 "symbols" syntax table;
  1117 
  1118 * added token_translation interface (may translate name tokens in
  1119 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  1120 the current print_mode); IMPORTANT: user print translation functions
  1121 are responsible for marking newly introduced bounds
  1122 (Syntax.mark_boundT);
  1123 
  1124 * token translations for modes "xterm" and "xterm_color" that display
  1125 names in bold, underline etc. or colors (which requires a color
  1126 version of xterm);
  1127 
  1128 * infixes may now be declared with names independent of their syntax;
  1129 
  1130 * added typed_print_translation (like print_translation, but may
  1131 access type of constant);
  1132 
  1133 
  1134 *** Classical Reasoner ***
  1135 
  1136 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  1137 some limitations.  Blast_tac...
  1138   + ignores addss, addbefore, addafter; this restriction is intrinsic
  1139   + ignores elimination rules that don't have the correct format
  1140         (the conclusion MUST be a formula variable)
  1141   + ignores types, which can make HOL proofs fail
  1142   + rules must not require higher-order unification, e.g. apply_type in ZF
  1143     [message "Function Var's argument not a bound variable" relates to this]
  1144   + its proof strategy is more general but can actually be slower
  1145 
  1146 * substitution with equality assumptions no longer permutes other
  1147 assumptions;
  1148 
  1149 * minor changes in semantics of addafter (now called addaltern); renamed
  1150 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  1151 (and access functions for it);
  1152 
  1153 * improved combination of classical reasoner and simplifier:
  1154   + functions for handling clasimpsets
  1155   + improvement of addss: now the simplifier is called _after_ the
  1156     safe steps.
  1157   + safe variant of addss called addSss: uses safe simplifications
  1158     _during_ the safe steps. It is more complete as it allows multiple
  1159     instantiations of unknowns (e.g. with slow_tac).
  1160 
  1161 *** Simplifier ***
  1162 
  1163 * added interface for simplification procedures (functions that
  1164 produce *proven* rewrite rules on the fly, depending on current
  1165 redex);
  1166 
  1167 * ordering on terms as parameter (used for ordered rewriting);
  1168 
  1169 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  1170 
  1171 * the solver is now split into a safe and an unsafe part.
  1172 This should be invisible for the normal user, except that the
  1173 functions setsolver and addsolver have been renamed to setSolver and
  1174 addSolver; added safe_asm_full_simp_tac;
  1175 
  1176 
  1177 *** HOL ***
  1178 
  1179 * a generic induction tactic `induct_tac' which works for all datatypes and
  1180 also for type `nat';
  1181 
  1182 * a generic case distinction tactic `exhaust_tac' which works for all
  1183 datatypes and also for type `nat';
  1184 
  1185 * each datatype comes with a function `size';
  1186 
  1187 * patterns in case expressions allow tuple patterns as arguments to
  1188 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  1189 
  1190 * primrec now also works with type nat;
  1191 
  1192 * recdef: a new declaration form, allows general recursive functions to be
  1193 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  1194 
  1195 * the constant for negation has been renamed from "not" to "Not" to
  1196 harmonize with FOL, ZF, LK, etc.;
  1197 
  1198 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  1199 infinite lists;
  1200 
  1201 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  1202 
  1203 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  1204 problems in commutative rings, using axiomatic type classes for + and *;
  1205 
  1206 * more examples in HOL/MiniML and HOL/Auth;
  1207 
  1208 * more default rewrite rules for quantifiers, union/intersection;
  1209 
  1210 * a new constant `arbitrary == @x.False';
  1211 
  1212 * HOLCF/IOA replaces old HOL/IOA;
  1213 
  1214 * HOLCF changes: derived all rules and arities
  1215   + axiomatic type classes instead of classes
  1216   + typedef instead of faking type definitions
  1217   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  1218   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  1219   + eliminated the types void, one, tr
  1220   + use unit lift and bool lift (with translations) instead of one and tr
  1221   + eliminated blift from Lift3.thy (use Def instead of blift)
  1222   all eliminated rules are derived as theorems --> no visible changes ;
  1223 
  1224 
  1225 *** ZF ***
  1226 
  1227 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  1228 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  1229 as ZF_cs addSIs [equalityI];
  1230 
  1231 
  1232 
  1233 New in Isabelle94-7 (November 96)
  1234 ---------------------------------
  1235 
  1236 * allowing negative levels (as offsets) in prlev and choplev;
  1237 
  1238 * super-linear speedup for large simplifications;
  1239 
  1240 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  1241 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  1242 FAIL); can suppress it using the command Delsimps (ex_simps @
  1243 all_simps); De Morgan laws are also now included, by default;
  1244 
  1245 * improved printing of ==>  :  ~:
  1246 
  1247 * new object-logic "Sequents" adds linear logic, while replacing LK
  1248 and Modal (thanks to Sara Kalvala);
  1249 
  1250 * HOL/Auth: correctness proofs for authentication protocols;
  1251 
  1252 * HOL: new auto_tac combines rewriting and classical reasoning (many
  1253 examples on HOL/Auth);
  1254 
  1255 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  1256 the rewriter and classical reasoner simultaneously;
  1257 
  1258 * function uresult no longer returns theorems in "standard" format;
  1259 regain previous version by: val uresult = standard o uresult;
  1260 
  1261 
  1262 
  1263 New in Isabelle94-6
  1264 -------------------
  1265 
  1266 * oracles -- these establish an interface between Isabelle and trusted
  1267 external reasoners, which may deliver results as theorems;
  1268 
  1269 * proof objects (in particular record all uses of oracles);
  1270 
  1271 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  1272 
  1273 * "constdefs" section in theory files;
  1274 
  1275 * "primrec" section (HOL) no longer requires names;
  1276 
  1277 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  1278 
  1279 
  1280 
  1281 New in Isabelle94-5
  1282 -------------------
  1283 
  1284 * reduced space requirements;
  1285 
  1286 * automatic HTML generation from theories;
  1287 
  1288 * theory files no longer require "..." (quotes) around most types;
  1289 
  1290 * new examples, including two proofs of the Church-Rosser theorem;
  1291 
  1292 * non-curried (1994) version of HOL is no longer distributed;
  1293 
  1294 
  1295 
  1296 New in Isabelle94-4
  1297 -------------------
  1298 
  1299 * greatly reduced space requirements;
  1300 
  1301 * theory files (.thy) no longer require \...\ escapes at line breaks;
  1302 
  1303 * searchable theorem database (see the section "Retrieving theorems" on
  1304 page 8 of the Reference Manual);
  1305 
  1306 * new examples, including Grabczewski's monumental case study of the
  1307 Axiom of Choice;
  1308 
  1309 * The previous version of HOL renamed to Old_HOL;
  1310 
  1311 * The new version of HOL (previously called CHOL) uses a curried syntax
  1312 for functions.  Application looks like f a b instead of f(a,b);
  1313 
  1314 * Mutually recursive inductive definitions finally work in HOL;
  1315 
  1316 * In ZF, pattern-matching on tuples is now available in all abstractions and
  1317 translates to the operator "split";
  1318 
  1319 
  1320 
  1321 New in Isabelle94-3
  1322 -------------------
  1323 
  1324 * new infix operator, addss, allowing the classical reasoner to
  1325 perform simplification at each step of its search.  Example:
  1326         fast_tac (cs addss ss)
  1327 
  1328 * a new logic, CHOL, the same as HOL, but with a curried syntax
  1329 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  1330 look like (a,b) instead of <a,b>;
  1331 
  1332 * PLEASE NOTE: CHOL will eventually replace HOL!
  1333 
  1334 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  1335 It translates to the operator "split".  A new theory of integers is available;
  1336 
  1337 * In ZF, integer numerals now denote two's-complement binary integers.
  1338 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  1339 
  1340 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  1341 of the Axiom of Choice;
  1342 
  1343 
  1344 
  1345 New in Isabelle94-2
  1346 -------------------
  1347 
  1348 * Significantly faster resolution;
  1349 
  1350 * the different sections in a .thy file can now be mixed and repeated
  1351 freely;
  1352 
  1353 * Database of theorems for FOL, HOL and ZF.  New
  1354 commands including qed, qed_goal and bind_thm store theorems in the database.
  1355 
  1356 * Simple database queries: return a named theorem (get_thm) or all theorems of
  1357 a given theory (thms_of), or find out what theory a theorem was proved in
  1358 (theory_of_thm);
  1359 
  1360 * Bugs fixed in the inductive definition and datatype packages;
  1361 
  1362 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  1363 and HOL_dup_cs obsolete;
  1364 
  1365 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  1366 have been removed;
  1367 
  1368 * Simpler definition of function space in ZF;
  1369 
  1370 * new results about cardinal and ordinal arithmetic in ZF;
  1371 
  1372 * 'subtype' facility in HOL for introducing new types as subsets of existing
  1373 types;
  1374 
  1375 
  1376 $Id$