NEWS
author wenzelm
Wed Jul 12 16:44:34 2000 +0200 (2000-07-12)
changeset 9288 06a55195741b
parent 9239 b31c2132176a
child 9330 6861e3b00155
permissions -rw-r--r--
infix 'OF' is a version of 'MRS' with more appropriate argument order;
     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: 0 is now overloaded, so the type constraint ::nat may sometimes be
    18 needed;
    19 
    20 * HOL: the constant for f``x is now "image" rather than "op ``";
    21 
    22 * HOL: the cartesian product is now "<*>" instead of "Times"; the
    23 lexicographic product is now "<*lex*>" instead of "**";
    24 
    25 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
    26 
    27 * HOL: simplification no longer dives into case-expressions
    28 
    29 * HOL: the recursion equations generated by 'recdef' are now called
    30 f.simps instead of f.rules;
    31 
    32 * HOL: theory Sexp now in HOL/Induct examples (used to be part of main
    33 HOL, but was unused); should better use HOL's datatype package anyway;
    34 
    35 * HOL/Real: "rabs" replaced by overloaded "abs" function;
    36 
    37 * HOL/ML: even fewer consts are declared as global (see theories Ord,
    38 Lfp, Gfp, WF); this only affects ML packages that refer to const names
    39 internally;
    40 
    41 * Isar: changed syntax of local blocks from {{ }} to { };
    42 
    43 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
    44   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
    45 use instead the strong form,
    46   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
    47 In HOL, FOR and ZF the function cla_make_elim will create such rules
    48 from destruct-rules;
    49 
    50 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
    51 timing flag supersedes proof_timing and Toplevel.trace;
    52 
    53 * ML: PureThy.add_thms/add_axioms/add_defs return theorems as well;
    54 
    55 * LaTeX: several improvements of isabelle.sty;
    56 
    57 
    58 *** Document preparation ***
    59 
    60 * formal comments (text blocks etc.) in new-style theories may now
    61 contain antiquotations of thm/prop/term/typ to be presented according
    62 to latex print mode; concrete syntax is like this: @{term[show_types]
    63 "f(x) = a + x"};
    64 
    65 * isatool mkdir provides easy setup of Isabelle session directories,
    66 including proper document sources;
    67 
    68 * generated LaTeX sources are now deleted after successful run
    69 (isatool document -c); may retain a copy somewhere else via -D option
    70 of isatool usedir;
    71 
    72 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
    73 style files, achieving self-contained LaTeX sources;
    74 
    75 * old-style theories now produce (crude) LaTeX output as well;
    76 
    77 * browser info session directories are now self-contained (may be put
    78 on WWW server seperately);
    79 
    80 
    81 *** Isar ***
    82 
    83 * Pure: local results and corresponding term bindings are now subject
    84 to Hindley-Milner polymorphism (similar to ML); this accommodates
    85 incremental type-inference nicely;
    86 
    87 * Pure: new 'obtain' language element supports generalized existence
    88 reasoning;
    89 
    90 * Pure: new calculational elements 'moreover' and 'ultimately' support
    91 plain accumulation of results, without applying any rules yet;
    92 
    93 * Pure: scalable support for case-analysis type proofs: new 'case'
    94 language element refers to local contexts symbolically, as produced by
    95 certain proof methods; internally, case names are attached to theorems
    96 as "tags";
    97 
    98 * Pure: changed syntax of local blocks from {{ }} to { };
    99 
   100 * Pure: syntax of sorts made inner, i.e. have to write "{a, b, c}"
   101 instead of {a, b, c};
   102 
   103 * Pure now provides its own version of intro/elim/dest attributes;
   104 useful for building new logics, but beware of confusion with the
   105 Provers/classical ones;
   106 
   107 * Pure: the local context of (non-atomic) goals is provided via case
   108 name 'antecedent';
   109 
   110 * Pure: removed obsolete 'transfer' attribute (transfer of thms to the
   111 current context is now done automatically);
   112 
   113 * Pure: theory command 'hide' removes declarations from
   114 class/type/const name spaces;
   115 
   116 * Pure: theory command 'method_setup' provides a simple interface for
   117 definining proof methods in ML;
   118 
   119 * Provers: splitter support (via 'split' attribute and 'simp' method
   120 modifier); 'simp' method: 'only:' modifier removes loopers as well
   121 (including splits);
   122 
   123 * HOL: new proof method 'cases' and improved version of 'induct' now
   124 support named cases; major packages (inductive, datatype, primrec,
   125 recdef) support case names and properly name parameters;
   126 
   127 * HOL: removed 'case_split' thm binding, should use 'cases' proof
   128 method anyway;
   129 
   130 * HOL/Calculation: new rules for substitution in inequalities
   131 (monotonicity conditions are extracted to be proven terminally);
   132 
   133 * names of theorems etc. may be natural numbers as well;
   134 
   135 * Provers: intro/elim/dest attributes: changed ! / !! flags to ? / ??;
   136 
   137 * 'pr' command: optional goals_limit argument; no longer prints theory
   138 contexts, but only proof states;
   139 
   140 * diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
   141 additional print modes to be specified; e.g. "pr(latex)" will print
   142 proof state according to the Isabelle LaTeX style;
   143 
   144 * improved support for emulating tactic scripts, including proof
   145 methods 'tactic', 'res_inst_tac' etc., 'subgoal_tac', and 'case_tac' /
   146 'induct_tac' (for HOL datatypes);
   147 
   148 * simplified (more robust) goal selection of proof methods: 1st goal,
   149 all goals, or explicit goal specifier (tactic emulation); thus 'proof
   150 method scripts' have to be in depth-first order;
   151 
   152 * tuned 'let' syntax: replaced 'as' keyword by 'and';
   153 
   154 * removed 'help' command, which hasn't been too helpful anyway; should
   155 instead use individual commands for printing items (print_commands,
   156 print_methods etc.);
   157 
   158 * added 'nothing' --- the empty list of theorems;
   159 
   160 
   161 *** HOL ***
   162 
   163 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog
   164 
   165 * HOL/Algebra: new theory of rings and univariate polynomials, by
   166 Clemens Ballarin;
   167 
   168 * HOL/record: fixed select-update simplification procedure to handle
   169 extended records as well; admit "r" as field name;
   170 
   171 * HOL/ex: new theory Factorization proving the Fundamental Theorem of
   172 Arithmetic, by Thomas M Rasmussen;
   173 
   174 * HOL/ex/Multiquote: multiple nested quotations and anti-quotations --
   175 basically a generalized version of de-Bruijn representation; very
   176 useful in avoiding lifting all operations;
   177 
   178 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   179 
   180 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
   181 other numeric types and also as the identity of groups, rings, etc.;
   182 
   183 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
   184 Types nat and int belong to this axclass;
   185 
   186 * greatly improved simplification involving numerals of type nat, int, real:
   187    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
   188    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
   189   two terms #m*u and #n*u are replaced by #(m+n)*u
   190     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
   191   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
   192     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
   193 
   194 * HOL: new version of "case_tac" subsumes both boolean case split and
   195 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
   196 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
   197 
   198 * HOL: simplification no longer dives into case-expressions: only the
   199 selector expression is simplified, but not the remaining arms. To
   200 enable full simplification of case-expressions for datatype t, you
   201 need to remove t.weak_case_cong from the simpset, either permanently
   202 (Delcongs[thm"t.weak_case_cong"];) or locally (delcongs [...]).
   203 
   204 * HOL/recdef: the recursion equations generated by 'recdef' for
   205 function 'f' are now called f.simps instead of f.rules; if all
   206 termination conditions are proved automatically, these simplification
   207 rules are added to the simpset, as in primrec; rules may be named
   208 individually as well, resulting in a separate list of theorems for
   209 each equation;
   210 
   211 * HOL: new (overloaded) notation for the set of elements below/above some
   212 element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
   213 
   214 * HOL: theorems impI, allI, ballI bound as "strip";
   215 
   216 * theory Sexp now in HOL/Induct examples (used to be part of main HOL,
   217 but was unused);
   218 
   219 * fewer consts declared as global (e.g. have to refer to "Lfp.lfp"
   220 instead of "lfp" internally; affects ML packages only);
   221 
   222 
   223 *** General ***
   224 
   225 * improved name spaces: ambiguous output is qualified; support for
   226 hiding of names;
   227 
   228 * compression of ML heaps images may now be controlled via -c option
   229 of isabelle and isatool usedir (currently only observed by Poly/ML);
   230 
   231 * provide TAGS file for Isabelle sources;
   232 
   233 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
   234 order;
   235 
   236 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
   237 timing flag supersedes proof_timing and Toplevel.trace;
   238 
   239 * ML: new combinators |>> and |>>> for incremental transformations
   240 with secondary results (e.g. certain theory extensions):
   241 
   242 
   243 
   244 New in Isabelle99 (October 1999)
   245 --------------------------------
   246 
   247 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   248 
   249 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
   250 are no longer simplified.  (This allows the simplifier to unfold recursive
   251 functional programs.)  To restore the old behaviour, declare
   252 
   253     Delcongs [if_weak_cong];
   254 
   255 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
   256 complement;
   257 
   258 * HOL: the predicate "inj" is now defined by translation to "inj_on";
   259 
   260 * HOL/datatype: mutual_induct_tac no longer exists --
   261   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
   262 
   263 * HOL/typedef: fixed type inference for representing set; type
   264 arguments now have to occur explicitly on the rhs as type constraints;
   265 
   266 * ZF: The con_defs part of an inductive definition may no longer refer
   267 to constants declared in the same theory;
   268 
   269 * HOL, ZF: the function mk_cases, generated by the inductive
   270 definition package, has lost an argument.  To simplify its result, it
   271 uses the default simpset instead of a supplied list of theorems.
   272 
   273 * HOL/List: the constructors of type list are now Nil and Cons;
   274 
   275 * Simplifier: the type of the infix ML functions
   276         setSSolver addSSolver setSolver addSolver
   277 is now  simpset * solver -> simpset  where `solver' is a new abstract type
   278 for packaging solvers. A solver is created via
   279         mk_solver: string -> (thm list -> int -> tactic) -> solver
   280 where the string argument is only a comment.
   281 
   282 
   283 *** Proof tools ***
   284 
   285 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
   286 decision procedure for linear arithmetic. Currently it is used for
   287 types `nat', `int', and `real' in HOL (see below); it can, should and
   288 will be instantiated for other types and logics as well.
   289 
   290 * The simplifier now accepts rewrite rules with flexible heads, eg
   291      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
   292   They are applied like any rule with a non-pattern lhs, i.e. by first-order
   293   matching.
   294 
   295 
   296 *** General ***
   297 
   298 * New Isabelle/Isar subsystem provides an alternative to traditional
   299 tactical theorem proving; together with the ProofGeneral/isar user
   300 interface it offers an interactive environment for developing human
   301 readable proof documents (Isar == Intelligible semi-automated
   302 reasoning); for further information see isatool doc isar-ref,
   303 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
   304 
   305 * improved presentation of theories: better HTML markup (including
   306 colors), graph views in several sizes; isatool usedir now provides a
   307 proper interface for user theories (via -P option); actual document
   308 preparation based on (PDF)LaTeX is available as well (for new-style
   309 theories only); see isatool doc system for more information;
   310 
   311 * native support for Proof General, both for classic Isabelle and
   312 Isabelle/Isar;
   313 
   314 * ML function thm_deps visualizes dependencies of theorems and lemmas,
   315 using the graph browser tool;
   316 
   317 * Isabelle manuals now also available as PDF;
   318 
   319 * theory loader rewritten from scratch (may not be fully
   320 bug-compatible); old loadpath variable has been replaced by show_path,
   321 add_path, del_path, reset_path functions; new operations such as
   322 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
   323 isatool doc ref);
   324 
   325 * improved isatool install: option -k creates KDE application icon,
   326 option -p DIR installs standalone binaries;
   327 
   328 * added ML_PLATFORM setting (useful for cross-platform installations);
   329 more robust handling of platform specific ML images for SML/NJ;
   330 
   331 * the settings environment is now statically scoped, i.e. it is never
   332 created again in sub-processes invoked from isabelle, isatool, or
   333 Isabelle;
   334 
   335 * path element specification '~~' refers to '$ISABELLE_HOME';
   336 
   337 * in locales, the "assumes" and "defines" parts may be omitted if
   338 empty;
   339 
   340 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
   341 long arrows);
   342 
   343 * new print_mode "HTML";
   344 
   345 * new flag show_tags controls display of tags of theorems (which are
   346 basically just comments that may be attached by some tools);
   347 
   348 * Isamode 2.6 requires patch to accomodate change of Isabelle font
   349 mode and goal output format:
   350 
   351 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
   352 244c244
   353 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
   354 ---
   355 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
   356 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
   357 181c181
   358 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
   359 ---
   360 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
   361 
   362 * function bind_thms stores lists of theorems (cf. bind_thm);
   363 
   364 * new shorthand tactics ftac, eatac, datac, fatac;
   365 
   366 * qed (and friends) now accept "" as result name; in that case the
   367 theorem is not stored, but proper checks and presentation of the
   368 result still apply;
   369 
   370 * theorem database now also indexes constants "Trueprop", "all",
   371 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
   372 
   373 
   374 *** HOL ***
   375 
   376 ** HOL arithmetic **
   377 
   378 * There are now decision procedures for linear arithmetic over nat and
   379 int:
   380 
   381 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
   382 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
   383 are treated as atomic; subformulae not involving type `nat' or `int'
   384 are ignored; quantified subformulae are ignored unless they are
   385 positive universal or negative existential. The tactic has to be
   386 invoked by hand and can be a little bit slow. In particular, the
   387 running time is exponential in the number of occurrences of `min' and
   388 `max', and `-' on `nat'.
   389 
   390 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
   391 (negated) (in)equalities among the premises and the conclusion into
   392 account (i.e. no compound formulae) and does not know about `min' and
   393 `max', and `-' on `nat'. It is fast and is used automatically by the
   394 simplifier.
   395 
   396 NB: At the moment, these decision procedures do not cope with mixed
   397 nat/int formulae where the two parts interact, such as `m < n ==>
   398 int(m) < int(n)'.
   399 
   400 * HOL/Numeral provides a generic theory of numerals (encoded
   401 efficiently as bit strings); setup for types nat/int/real is in place;
   402 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
   403 int, existing theories and proof scripts may require a few additional
   404 type constraints;
   405 
   406 * integer division and remainder can now be performed on constant
   407 arguments;
   408 
   409 * many properties of integer multiplication, division and remainder
   410 are now available;
   411 
   412 * An interface to the Stanford Validity Checker (SVC) is available through the
   413 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
   414 are proved automatically.  SVC must be installed separately, and its results
   415 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
   416 invocation of the underlying oracle).  For SVC see
   417   http://verify.stanford.edu/SVC
   418 
   419 * IsaMakefile: the HOL-Real target now builds an actual image;
   420 
   421 
   422 ** HOL misc **
   423 
   424 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
   425 (in Isabelle/Isar) -- by Gertrud Bauer;
   426 
   427 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
   428 analysis for assembly languages with subtypes;
   429 
   430 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
   431 -- avoids syntactic ambiguities and treats state, transition, and
   432 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
   433 changed syntax and (many) tactics;
   434 
   435 * HOL/inductive: Now also handles more general introduction rules such
   436   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
   437   theorems are now maintained within the theory (maintained via the
   438   "mono" attribute);
   439 
   440 * HOL/datatype: Now also handles arbitrarily branching datatypes
   441   (using function types) such as
   442 
   443   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
   444 
   445 * HOL/record: record_simproc (part of the default simpset) takes care
   446 of selectors applied to updated records; record_split_tac is no longer
   447 part of the default claset; update_defs may now be removed from the
   448 simpset in many cases; COMPATIBILITY: old behavior achieved by
   449 
   450   claset_ref () := claset() addSWrapper record_split_wrapper;
   451   Delsimprocs [record_simproc]
   452 
   453 * HOL/typedef: fixed type inference for representing set; type
   454 arguments now have to occur explicitly on the rhs as type constraints;
   455 
   456 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
   457 names rather than an ML expression;
   458 
   459 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
   460 supplied later.  Program schemes can be defined, such as
   461     "While B C s = (if B s then While B C (C s) else s)"
   462 where the well-founded relation can be chosen after B and C have been given.
   463 
   464 * HOL/List: the constructors of type list are now Nil and Cons;
   465 INCOMPATIBILITY: while [] and infix # syntax is still there, of
   466 course, ML tools referring to List.list.op # etc. have to be adapted;
   467 
   468 * HOL_quantifiers flag superseded by "HOL" print mode, which is
   469 disabled by default; run isabelle with option -m HOL to get back to
   470 the original Gordon/HOL-style output;
   471 
   472 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
   473 ALL x<=y. P, EX x<y. P, EX x<=y. P;
   474 
   475 * HOL basic syntax simplified (more orthogonal): all variants of
   476 All/Ex now support plain / symbolic / HOL notation; plain syntax for
   477 Eps operator is provided as well: "SOME x. P[x]";
   478 
   479 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
   480 
   481 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
   482 thus available for user theories;
   483 
   484 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
   485 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
   486 time;
   487 
   488 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
   489 several times and then mp;
   490 
   491 
   492 *** LK ***
   493 
   494 * the notation <<...>> is now available as a notation for sequences of
   495 formulas;
   496 
   497 * the simplifier is now installed
   498 
   499 * the axiom system has been generalized (thanks to Soren Heilmann)
   500 
   501 * the classical reasoner now has a default rule database
   502 
   503 
   504 *** ZF ***
   505 
   506 * new primrec section allows primitive recursive functions to be given
   507 directly (as in HOL) over datatypes and the natural numbers;
   508 
   509 * new tactics induct_tac and exhaust_tac for induction (or case
   510 analysis) over datatypes and the natural numbers;
   511 
   512 * the datatype declaration of type T now defines the recursor T_rec;
   513 
   514 * simplification automatically does freeness reasoning for datatype
   515 constructors;
   516 
   517 * automatic type-inference, with AddTCs command to insert new
   518 type-checking rules;
   519 
   520 * datatype introduction rules are now added as Safe Introduction rules
   521 to the claset;
   522 
   523 * the syntax "if P then x else y" is now available in addition to
   524 if(P,x,y);
   525 
   526 
   527 *** Internal programming interfaces ***
   528 
   529 * tuned simplifier trace output; new flag debug_simp;
   530 
   531 * structures Vartab / Termtab (instances of TableFun) offer efficient
   532 tables indexed by indexname_ord / term_ord (compatible with aconv);
   533 
   534 * AxClass.axclass_tac lost the theory argument;
   535 
   536 * tuned current_goals_markers semantics: begin / end goal avoids
   537 printing empty lines;
   538 
   539 * removed prs and prs_fn hook, which was broken because it did not
   540 include \n in its semantics, forcing writeln to add one
   541 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
   542 string -> unit if you really want to output text without newline;
   543 
   544 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
   545 plain output, interface builders may have to enable 'isabelle_font'
   546 mode to get Isabelle font glyphs as before;
   547 
   548 * refined token_translation interface; INCOMPATIBILITY: output length
   549 now of type real instead of int;
   550 
   551 * theory loader actions may be traced via new ThyInfo.add_hook
   552 interface (see src/Pure/Thy/thy_info.ML); example application: keep
   553 your own database of information attached to *whole* theories -- as
   554 opposed to intra-theory data slots offered via TheoryDataFun;
   555 
   556 * proper handling of dangling sort hypotheses (at last!);
   557 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
   558 extra sort hypotheses that can be witnessed from the type signature;
   559 the force_strip_shyps flag is gone, any remaining shyps are simply
   560 left in the theorem (with a warning issued by strip_shyps_warning);
   561 
   562 
   563 
   564 New in Isabelle98-1 (October 1998)
   565 ----------------------------------
   566 
   567 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   568 
   569 * several changes of automated proof tools;
   570 
   571 * HOL: major changes to the inductive and datatype packages, including
   572 some minor incompatibilities of theory syntax;
   573 
   574 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
   575 called `inj_on';
   576 
   577 * HOL: removed duplicate thms in Arith:
   578   less_imp_add_less  should be replaced by  trans_less_add1
   579   le_imp_add_le      should be replaced by  trans_le_add1
   580 
   581 * HOL: unary minus is now overloaded (new type constraints may be
   582 required);
   583 
   584 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
   585 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
   586 now taken as an integer constant.
   587 
   588 * Pure: ML function 'theory_of' renamed to 'theory';
   589 
   590 
   591 *** Proof tools ***
   592 
   593 * Simplifier:
   594   1. Asm_full_simp_tac is now more aggressive.
   595      1. It will sometimes reorient premises if that increases their power to
   596         simplify.
   597      2. It does no longer proceed strictly from left to right but may also
   598         rotate premises to achieve further simplification.
   599      For compatibility reasons there is now Asm_lr_simp_tac which is like the
   600      old Asm_full_simp_tac in that it does not rotate premises.
   601   2. The simplifier now knows a little bit about nat-arithmetic.
   602 
   603 * Classical reasoner: wrapper mechanism for the classical reasoner now
   604 allows for selected deletion of wrappers, by introduction of names for
   605 wrapper functionals.  This implies that addbefore, addSbefore,
   606 addaltern, and addSaltern now take a pair (name, tactic) as argument,
   607 and that adding two tactics with the same name overwrites the first
   608 one (emitting a warning).
   609   type wrapper = (int -> tactic) -> (int -> tactic)
   610   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
   611   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
   612   delWrapper, delSWrapper: claset *  string            -> claset
   613   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
   614 
   615 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
   616 semantics; addbefore now affects only the unsafe part of step_tac
   617 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
   618 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
   619 by Force_tac;
   620 
   621 * Classical reasoner: setwrapper to setWrapper and compwrapper to
   622 compWrapper; added safe wrapper (and access functions for it);
   623 
   624 * HOL/split_all_tac is now much faster and fails if there is nothing
   625 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
   626 and the names of the automatically generated variables have changed.
   627 split_all_tac has moved within claset() from unsafe wrappers to safe
   628 wrappers, which means that !!-bound variables are split much more
   629 aggressively, and safe_tac and clarify_tac now split such variables.
   630 If this splitting is not appropriate, use delSWrapper "split_all_tac".
   631 Note: the same holds for record_split_tac, which does the job of
   632 split_all_tac for record fields.
   633 
   634 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
   635 permanently to the default simpset using Addsplits just like
   636 Addsimps. They can be removed via Delsplits just like
   637 Delsimps. Lower-case versions are also available.
   638 
   639 * HOL/Simplifier: The rule split_if is now part of the default
   640 simpset. This means that the simplifier will eliminate all occurrences
   641 of if-then-else in the conclusion of a goal. To prevent this, you can
   642 either remove split_if completely from the default simpset by
   643 `Delsplits [split_if]' or remove it in a specific call of the
   644 simplifier using `... delsplits [split_if]'.  You can also add/delete
   645 other case splitting rules to/from the default simpset: every datatype
   646 generates suitable rules `split_t_case' and `split_t_case_asm' (where
   647 t is the name of the datatype).
   648 
   649 * Classical reasoner / Simplifier combination: new force_tac (and
   650 derivatives Force_tac, force) combines rewriting and classical
   651 reasoning (and whatever other tools) similarly to auto_tac, but is
   652 aimed to solve the given subgoal completely.
   653 
   654 
   655 *** General ***
   656 
   657 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
   658 and `goalw': the theory is no longer needed as an explicit argument -
   659 the current theory context is used; assumptions are no longer returned
   660 at the ML-level unless one of them starts with ==> or !!; it is
   661 recommended to convert to these new commands using isatool fixgoal
   662 (backup your sources first!);
   663 
   664 * new top-level commands 'thm' and 'thms' for retrieving theorems from
   665 the current theory context, and 'theory' to lookup stored theories;
   666 
   667 * new theory section 'locale' for declaring constants, assumptions and
   668 definitions that have local scope;
   669 
   670 * new theory section 'nonterminals' for purely syntactic types;
   671 
   672 * new theory section 'setup' for generic ML setup functions
   673 (e.g. package initialization);
   674 
   675 * the distribution now includes Isabelle icons: see
   676 lib/logo/isabelle-{small,tiny}.xpm;
   677 
   678 * isatool install - install binaries with absolute references to
   679 ISABELLE_HOME/bin;
   680 
   681 * isatool logo -- create instances of the Isabelle logo (as EPS);
   682 
   683 * print mode 'emacs' reserved for Isamode;
   684 
   685 * support multiple print (ast) translations per constant name;
   686 
   687 * theorems involving oracles are now printed with a suffixed [!];
   688 
   689 
   690 *** HOL ***
   691 
   692 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
   693 
   694 * HOL/inductive package reorganized and improved: now supports mutual
   695 definitions such as
   696 
   697   inductive EVEN ODD
   698     intrs
   699       null "0 : EVEN"
   700       oddI "n : EVEN ==> Suc n : ODD"
   701       evenI "n : ODD ==> Suc n : EVEN"
   702 
   703 new theorem list "elims" contains an elimination rule for each of the
   704 recursive sets; inductive definitions now handle disjunctive premises
   705 correctly (also ZF);
   706 
   707 INCOMPATIBILITIES: requires Inductive as an ancestor; component
   708 "mutual_induct" no longer exists - the induction rule is always
   709 contained in "induct";
   710 
   711 
   712 * HOL/datatype package re-implemented and greatly improved: now
   713 supports mutually recursive datatypes such as
   714 
   715   datatype
   716     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
   717             | SUM ('a aexp) ('a aexp)
   718             | DIFF ('a aexp) ('a aexp)
   719             | NUM 'a
   720   and
   721     'a bexp = LESS ('a aexp) ('a aexp)
   722             | AND ('a bexp) ('a bexp)
   723             | OR ('a bexp) ('a bexp)
   724 
   725 as well as indirectly recursive datatypes such as
   726 
   727   datatype
   728     ('a, 'b) term = Var 'a
   729                   | App 'b ((('a, 'b) term) list)
   730 
   731 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
   732 induction on mutually / indirectly recursive datatypes.
   733 
   734 Primrec equations are now stored in theory and can be accessed via
   735 <function_name>.simps.
   736 
   737 INCOMPATIBILITIES:
   738 
   739   - Theories using datatypes must now have theory Datatype as an
   740     ancestor.
   741   - The specific <typename>.induct_tac no longer exists - use the
   742     generic induct_tac instead.
   743   - natE has been renamed to nat.exhaust - use exhaust_tac
   744     instead of res_inst_tac ... natE. Note that the variable
   745     names in nat.exhaust differ from the names in natE, this
   746     may cause some "fragile" proofs to fail.
   747   - The theorems split_<typename>_case and split_<typename>_case_asm
   748     have been renamed to <typename>.split and <typename>.split_asm.
   749   - Since default sorts of type variables are now handled correctly,
   750     some datatype definitions may have to be annotated with explicit
   751     sort constraints.
   752   - Primrec definitions no longer require function name and type
   753     of recursive argument.
   754 
   755 Consider using isatool fixdatatype to adapt your theories and proof
   756 scripts to the new package (backup your sources first!).
   757 
   758 
   759 * HOL/record package: considerably improved implementation; now
   760 includes concrete syntax for record types, terms, updates; theorems
   761 for surjective pairing and splitting !!-bound record variables; proof
   762 support is as follows:
   763 
   764   1) standard conversions (selectors or updates applied to record
   765 constructor terms) are part of the standard simpset;
   766 
   767   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
   768 made part of standard simpset and claset via addIffs;
   769 
   770   3) a tactic for record field splitting (record_split_tac) is part of
   771 the standard claset (addSWrapper);
   772 
   773 To get a better idea about these rules you may retrieve them via
   774 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
   775 the name of your record type.
   776 
   777 The split tactic 3) conceptually simplifies by the following rule:
   778 
   779   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
   780 
   781 Thus any record variable that is bound by meta-all will automatically
   782 blow up into some record constructor term, consequently the
   783 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
   784 solve record problems automatically.
   785 
   786 
   787 * reorganized the main HOL image: HOL/Integ and String loaded by
   788 default; theory Main includes everything;
   789 
   790 * automatic simplification of integer sums and comparisons, using cancellation;
   791 
   792 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
   793 
   794 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
   795 
   796 * many new identities for unions, intersections, set difference, etc.;
   797 
   798 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
   799 called split_if, split_split, split_sum_case and split_nat_case (to go
   800 with add/delsplits);
   801 
   802 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
   803 (?x::unit) = (); this is made part of the default simpset, which COULD
   804 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
   805 'Delsimprocs [unit_eq_proc];' as last resort); also note that
   806 unit_abs_eta_conv is added in order to counter the effect of
   807 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
   808 %u.f();
   809 
   810 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
   811 makes more sense);
   812 
   813 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   814   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   815   disjointness reasoning but breaking a few old proofs.
   816 
   817 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
   818 to 'converse' from 'inverse' (for compatibility with ZF and some
   819 literature);
   820 
   821 * HOL/recdef can now declare non-recursive functions, with {} supplied as
   822 the well-founded relation;
   823 
   824 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
   825     Compl A.  The "Compl" syntax remains available as input syntax for this
   826     release ONLY.
   827 
   828 * HOL/Update: new theory of function updates:
   829     f(a:=b) == %x. if x=a then b else f x
   830 may also be iterated as in f(a:=b,c:=d,...);
   831 
   832 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
   833 
   834 * HOL/List:
   835   - new function list_update written xs[i:=v] that updates the i-th
   836     list position. May also be iterated as in xs[i:=a,j:=b,...].
   837   - new function `upt' written [i..j(] which generates the list
   838     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
   839     bound write [i..j], which is a shorthand for [i..j+1(].
   840   - new lexicographic orderings and corresponding wellfoundedness theorems.
   841 
   842 * HOL/Arith:
   843   - removed 'pred' (predecessor) function;
   844   - generalized some theorems about n-1;
   845   - many new laws about "div" and "mod";
   846   - new laws about greatest common divisors (see theory ex/Primes);
   847 
   848 * HOL/Relation: renamed the relational operator r^-1 "converse"
   849 instead of "inverse";
   850 
   851 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
   852   of the multiset ordering;
   853 
   854 * directory HOL/Real: a construction of the reals using Dedekind cuts
   855   (not included by default);
   856 
   857 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
   858 
   859 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
   860   programs, i.e. different program variables may have different types.
   861 
   862 * calling (stac rew i) now fails if "rew" has no effect on the goal
   863   [previously, this check worked only if the rewrite rule was unconditional]
   864   Now rew can involve either definitions or equalities (either == or =).
   865 
   866 
   867 *** ZF ***
   868 
   869 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
   870   only the theorems proved on ZF.ML;
   871 
   872 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   873   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   874   disjointness reasoning but breaking a few old proofs.
   875 
   876 * ZF/Update: new theory of function updates
   877     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
   878   may also be iterated as in f(a:=b,c:=d,...);
   879 
   880 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
   881 
   882 * calling (stac rew i) now fails if "rew" has no effect on the goal
   883   [previously, this check worked only if the rewrite rule was unconditional]
   884   Now rew can involve either definitions or equalities (either == or =).
   885 
   886 * case_tac provided for compatibility with HOL
   887     (like the old excluded_middle_tac, but with subgoals swapped)
   888 
   889 
   890 *** Internal programming interfaces ***
   891 
   892 * Pure: several new basic modules made available for general use, see
   893 also src/Pure/README;
   894 
   895 * improved the theory data mechanism to support encapsulation (data
   896 kind name replaced by private Object.kind, acting as authorization
   897 key); new type-safe user interface via functor TheoryDataFun; generic
   898 print_data function becomes basically useless;
   899 
   900 * removed global_names compatibility flag -- all theory declarations
   901 are qualified by default;
   902 
   903 * module Pure/Syntax now offers quote / antiquote translation
   904 functions (useful for Hoare logic etc. with implicit dependencies);
   905 see HOL/ex/Antiquote for an example use;
   906 
   907 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
   908 cterm -> thm;
   909 
   910 * new tactical CHANGED_GOAL for checking that a tactic modifies a
   911 subgoal;
   912 
   913 * Display.print_goals function moved to Locale.print_goals;
   914 
   915 * standard print function for goals supports current_goals_markers
   916 variable for marking begin of proof, end of proof, start of goal; the
   917 default is ("", "", ""); setting current_goals_markers := ("<proof>",
   918 "</proof>", "<goal>") causes SGML like tagged proof state printing,
   919 for example;
   920 
   921 
   922 
   923 New in Isabelle98 (January 1998)
   924 --------------------------------
   925 
   926 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   927 
   928 * changed lexical syntax of terms / types: dots made part of long
   929 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
   930 
   931 * simpset (and claset) reference variable replaced by functions
   932 simpset / simpset_ref;
   933 
   934 * no longer supports theory aliases (via merge) and non-trivial
   935 implicit merge of thms' signatures;
   936 
   937 * most internal names of constants changed due to qualified names;
   938 
   939 * changed Pure/Sequence interface (see Pure/seq.ML);
   940 
   941 
   942 *** General Changes ***
   943 
   944 * hierachically structured name spaces (for consts, types, axms, thms
   945 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
   946 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
   947 isatool fixdots ensures space after dots (e.g. "%x. x"); set
   948 long_names for fully qualified output names; NOTE: ML programs
   949 (special tactics, packages etc.) referring to internal names may have
   950 to be adapted to cope with fully qualified names; in case of severe
   951 backward campatibility problems try setting 'global_names' at compile
   952 time to have enrything declared within a flat name space; one may also
   953 fine tune name declarations in theories via the 'global' and 'local'
   954 section;
   955 
   956 * reimplemented the implicit simpset and claset using the new anytype
   957 data filed in signatures; references simpset:simpset ref etc. are
   958 replaced by functions simpset:unit->simpset and
   959 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
   960 to patch your ML files accordingly;
   961 
   962 * HTML output now includes theory graph data for display with Java
   963 applet or isatool browser; data generated automatically via isatool
   964 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
   965 
   966 * defs may now be conditional; improved rewrite_goals_tac to handle
   967 conditional equations;
   968 
   969 * defs now admits additional type arguments, using TYPE('a) syntax;
   970 
   971 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
   972 creates a new theory node; implicit merge of thms' signatures is
   973 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
   974 transfer:theory->thm->thm in (rare) cases;
   975 
   976 * improved handling of draft signatures / theories; draft thms (and
   977 ctyps, cterms) are automatically promoted to real ones;
   978 
   979 * slightly changed interfaces for oracles: admit many per theory, named
   980 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
   981 
   982 * print_goals: optional output of const types (set show_consts and
   983 show_types);
   984 
   985 * improved output of warnings (###) and errors (***);
   986 
   987 * subgoal_tac displays a warning if the new subgoal has type variables;
   988 
   989 * removed old README and Makefiles;
   990 
   991 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
   992 
   993 * removed obsolete init_pps and init_database;
   994 
   995 * deleted the obsolete tactical STATE, which was declared by
   996     fun STATE tacfun st = tacfun st st;
   997 
   998 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
   999 (which abbreviates $HOME);
  1000 
  1001 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  1002 use isatool fixseq to adapt your ML programs (this works for fully
  1003 qualified references to the Sequence structure only!);
  1004 
  1005 * use_thy no longer requires writable current directory; it always
  1006 reloads .ML *and* .thy file, if either one is out of date;
  1007 
  1008 
  1009 *** Classical Reasoner ***
  1010 
  1011 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  1012 tactics that use classical reasoning to simplify a subgoal without
  1013 splitting it into several subgoals;
  1014 
  1015 * Safe_tac: like safe_tac but uses the default claset;
  1016 
  1017 
  1018 *** Simplifier ***
  1019 
  1020 * added simplification meta rules:
  1021     (asm_)(full_)simplify: simpset -> thm -> thm;
  1022 
  1023 * simplifier.ML no longer part of Pure -- has to be loaded by object
  1024 logics (again);
  1025 
  1026 * added prems argument to simplification procedures;
  1027 
  1028 * HOL, FOL, ZF: added infix function `addsplits':
  1029   instead of `<simpset> setloop (split_tac <thms>)'
  1030   you can simply write `<simpset> addsplits <thms>'
  1031 
  1032 
  1033 *** Syntax ***
  1034 
  1035 * TYPE('a) syntax for type reflection terms;
  1036 
  1037 * no longer handles consts with name "" -- declare as 'syntax' instead;
  1038 
  1039 * pretty printer: changed order of mixfix annotation preference (again!);
  1040 
  1041 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  1042 
  1043 
  1044 *** HOL ***
  1045 
  1046 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1047   with `addloop' of the simplifier to faciliate case splitting in premises.
  1048 
  1049 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  1050 
  1051 * HOL/Auth: new protocol proofs including some for the Internet
  1052   protocol TLS;
  1053 
  1054 * HOL/Map: new theory of `maps' a la VDM;
  1055 
  1056 * HOL/simplifier: simplification procedures nat_cancel_sums for
  1057 cancelling out common nat summands from =, <, <= (in)equalities, or
  1058 differences; simplification procedures nat_cancel_factor for
  1059 cancelling common factor from =, <, <= (in)equalities over natural
  1060 sums; nat_cancel contains both kinds of procedures, it is installed by
  1061 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  1062 
  1063 * HOL/simplifier: terms of the form
  1064   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  1065   are rewritten to
  1066   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  1067   and those of the form
  1068   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  1069   are rewritten to
  1070   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  1071 
  1072 * HOL/datatype
  1073   Each datatype `t' now comes with a theorem `split_t_case' of the form
  1074 
  1075   P(t_case f1 ... fn x) =
  1076      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  1077         ...
  1078        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  1079      )
  1080 
  1081   and a theorem `split_t_case_asm' of the form
  1082 
  1083   P(t_case f1 ... fn x) =
  1084     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  1085         ...
  1086        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  1087      )
  1088   which can be added to a simpset via `addsplits'. The existing theorems
  1089   expand_list_case and expand_option_case have been renamed to
  1090   split_list_case and split_option_case.
  1091 
  1092 * HOL/Arithmetic:
  1093   - `pred n' is automatically converted to `n-1'.
  1094     Users are strongly encouraged not to use `pred' any longer,
  1095     because it will disappear altogether at some point.
  1096   - Users are strongly encouraged to write "0 < n" rather than
  1097     "n ~= 0". Theorems and proof tools have been modified towards this
  1098     `standard'.
  1099 
  1100 * HOL/Lists:
  1101   the function "set_of_list" has been renamed "set" (and its theorems too);
  1102   the function "nth" now takes its arguments in the reverse order and
  1103   has acquired the infix notation "!" as in "xs!n".
  1104 
  1105 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  1106 
  1107 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  1108   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  1109 
  1110 * HOL/record: extensible records with schematic structural subtyping
  1111 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  1112 still lacks various theorems and concrete record syntax;
  1113 
  1114 
  1115 *** HOLCF ***
  1116 
  1117 * removed "axioms" and "generated by" sections;
  1118 
  1119 * replaced "ops" section by extended "consts" section, which is capable of
  1120   handling the continuous function space "->" directly;
  1121 
  1122 * domain package:
  1123   . proves theorems immediately and stores them in the theory,
  1124   . creates hierachical name space,
  1125   . now uses normal mixfix annotations (instead of cinfix...),
  1126   . minor changes to some names and values (for consistency),
  1127   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  1128   . separator between mutual domain defs: changed "," to "and",
  1129   . improved handling of sort constraints;  now they have to
  1130     appear on the left-hand side of the equations only;
  1131 
  1132 * fixed LAM <x,y,zs>.b syntax;
  1133 
  1134 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  1135 adm (%x. P (t x)), where P is chainfinite and t continuous;
  1136 
  1137 
  1138 *** FOL and ZF ***
  1139 
  1140 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1141   with `addloop' of the simplifier to faciliate case splitting in premises.
  1142 
  1143 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  1144 in HOL, they strip ALL and --> from proved theorems;
  1145 
  1146 
  1147 
  1148 New in Isabelle94-8 (May 1997)
  1149 ------------------------------
  1150 
  1151 *** General Changes ***
  1152 
  1153 * new utilities to build / run / maintain Isabelle etc. (in parts
  1154 still somewhat experimental); old Makefiles etc. still functional;
  1155 
  1156 * new 'Isabelle System Manual';
  1157 
  1158 * INSTALL text, together with ./configure and ./build scripts;
  1159 
  1160 * reimplemented type inference for greater efficiency, better error
  1161 messages and clean internal interface;
  1162 
  1163 * prlim command for dealing with lots of subgoals (an easier way of
  1164 setting goals_limit);
  1165 
  1166 
  1167 *** Syntax ***
  1168 
  1169 * supports alternative (named) syntax tables (parser and pretty
  1170 printer); internal interface is provided by add_modesyntax(_i);
  1171 
  1172 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  1173 be used in conjunction with the Isabelle symbol font; uses the
  1174 "symbols" syntax table;
  1175 
  1176 * added token_translation interface (may translate name tokens in
  1177 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  1178 the current print_mode); IMPORTANT: user print translation functions
  1179 are responsible for marking newly introduced bounds
  1180 (Syntax.mark_boundT);
  1181 
  1182 * token translations for modes "xterm" and "xterm_color" that display
  1183 names in bold, underline etc. or colors (which requires a color
  1184 version of xterm);
  1185 
  1186 * infixes may now be declared with names independent of their syntax;
  1187 
  1188 * added typed_print_translation (like print_translation, but may
  1189 access type of constant);
  1190 
  1191 
  1192 *** Classical Reasoner ***
  1193 
  1194 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  1195 some limitations.  Blast_tac...
  1196   + ignores addss, addbefore, addafter; this restriction is intrinsic
  1197   + ignores elimination rules that don't have the correct format
  1198         (the conclusion MUST be a formula variable)
  1199   + ignores types, which can make HOL proofs fail
  1200   + rules must not require higher-order unification, e.g. apply_type in ZF
  1201     [message "Function Var's argument not a bound variable" relates to this]
  1202   + its proof strategy is more general but can actually be slower
  1203 
  1204 * substitution with equality assumptions no longer permutes other
  1205 assumptions;
  1206 
  1207 * minor changes in semantics of addafter (now called addaltern); renamed
  1208 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  1209 (and access functions for it);
  1210 
  1211 * improved combination of classical reasoner and simplifier:
  1212   + functions for handling clasimpsets
  1213   + improvement of addss: now the simplifier is called _after_ the
  1214     safe steps.
  1215   + safe variant of addss called addSss: uses safe simplifications
  1216     _during_ the safe steps. It is more complete as it allows multiple
  1217     instantiations of unknowns (e.g. with slow_tac).
  1218 
  1219 *** Simplifier ***
  1220 
  1221 * added interface for simplification procedures (functions that
  1222 produce *proven* rewrite rules on the fly, depending on current
  1223 redex);
  1224 
  1225 * ordering on terms as parameter (used for ordered rewriting);
  1226 
  1227 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  1228 
  1229 * the solver is now split into a safe and an unsafe part.
  1230 This should be invisible for the normal user, except that the
  1231 functions setsolver and addsolver have been renamed to setSolver and
  1232 addSolver; added safe_asm_full_simp_tac;
  1233 
  1234 
  1235 *** HOL ***
  1236 
  1237 * a generic induction tactic `induct_tac' which works for all datatypes and
  1238 also for type `nat';
  1239 
  1240 * a generic case distinction tactic `exhaust_tac' which works for all
  1241 datatypes and also for type `nat';
  1242 
  1243 * each datatype comes with a function `size';
  1244 
  1245 * patterns in case expressions allow tuple patterns as arguments to
  1246 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  1247 
  1248 * primrec now also works with type nat;
  1249 
  1250 * recdef: a new declaration form, allows general recursive functions to be
  1251 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  1252 
  1253 * the constant for negation has been renamed from "not" to "Not" to
  1254 harmonize with FOL, ZF, LK, etc.;
  1255 
  1256 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  1257 infinite lists;
  1258 
  1259 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  1260 
  1261 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  1262 problems in commutative rings, using axiomatic type classes for + and *;
  1263 
  1264 * more examples in HOL/MiniML and HOL/Auth;
  1265 
  1266 * more default rewrite rules for quantifiers, union/intersection;
  1267 
  1268 * a new constant `arbitrary == @x.False';
  1269 
  1270 * HOLCF/IOA replaces old HOL/IOA;
  1271 
  1272 * HOLCF changes: derived all rules and arities
  1273   + axiomatic type classes instead of classes
  1274   + typedef instead of faking type definitions
  1275   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  1276   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  1277   + eliminated the types void, one, tr
  1278   + use unit lift and bool lift (with translations) instead of one and tr
  1279   + eliminated blift from Lift3.thy (use Def instead of blift)
  1280   all eliminated rules are derived as theorems --> no visible changes ;
  1281 
  1282 
  1283 *** ZF ***
  1284 
  1285 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  1286 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  1287 as ZF_cs addSIs [equalityI];
  1288 
  1289 
  1290 
  1291 New in Isabelle94-7 (November 96)
  1292 ---------------------------------
  1293 
  1294 * allowing negative levels (as offsets) in prlev and choplev;
  1295 
  1296 * super-linear speedup for large simplifications;
  1297 
  1298 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  1299 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  1300 FAIL); can suppress it using the command Delsimps (ex_simps @
  1301 all_simps); De Morgan laws are also now included, by default;
  1302 
  1303 * improved printing of ==>  :  ~:
  1304 
  1305 * new object-logic "Sequents" adds linear logic, while replacing LK
  1306 and Modal (thanks to Sara Kalvala);
  1307 
  1308 * HOL/Auth: correctness proofs for authentication protocols;
  1309 
  1310 * HOL: new auto_tac combines rewriting and classical reasoning (many
  1311 examples on HOL/Auth);
  1312 
  1313 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  1314 the rewriter and classical reasoner simultaneously;
  1315 
  1316 * function uresult no longer returns theorems in "standard" format;
  1317 regain previous version by: val uresult = standard o uresult;
  1318 
  1319 
  1320 
  1321 New in Isabelle94-6
  1322 -------------------
  1323 
  1324 * oracles -- these establish an interface between Isabelle and trusted
  1325 external reasoners, which may deliver results as theorems;
  1326 
  1327 * proof objects (in particular record all uses of oracles);
  1328 
  1329 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  1330 
  1331 * "constdefs" section in theory files;
  1332 
  1333 * "primrec" section (HOL) no longer requires names;
  1334 
  1335 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  1336 
  1337 
  1338 
  1339 New in Isabelle94-5
  1340 -------------------
  1341 
  1342 * reduced space requirements;
  1343 
  1344 * automatic HTML generation from theories;
  1345 
  1346 * theory files no longer require "..." (quotes) around most types;
  1347 
  1348 * new examples, including two proofs of the Church-Rosser theorem;
  1349 
  1350 * non-curried (1994) version of HOL is no longer distributed;
  1351 
  1352 
  1353 
  1354 New in Isabelle94-4
  1355 -------------------
  1356 
  1357 * greatly reduced space requirements;
  1358 
  1359 * theory files (.thy) no longer require \...\ escapes at line breaks;
  1360 
  1361 * searchable theorem database (see the section "Retrieving theorems" on
  1362 page 8 of the Reference Manual);
  1363 
  1364 * new examples, including Grabczewski's monumental case study of the
  1365 Axiom of Choice;
  1366 
  1367 * The previous version of HOL renamed to Old_HOL;
  1368 
  1369 * The new version of HOL (previously called CHOL) uses a curried syntax
  1370 for functions.  Application looks like f a b instead of f(a,b);
  1371 
  1372 * Mutually recursive inductive definitions finally work in HOL;
  1373 
  1374 * In ZF, pattern-matching on tuples is now available in all abstractions and
  1375 translates to the operator "split";
  1376 
  1377 
  1378 
  1379 New in Isabelle94-3
  1380 -------------------
  1381 
  1382 * new infix operator, addss, allowing the classical reasoner to
  1383 perform simplification at each step of its search.  Example:
  1384         fast_tac (cs addss ss)
  1385 
  1386 * a new logic, CHOL, the same as HOL, but with a curried syntax
  1387 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  1388 look like (a,b) instead of <a,b>;
  1389 
  1390 * PLEASE NOTE: CHOL will eventually replace HOL!
  1391 
  1392 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  1393 It translates to the operator "split".  A new theory of integers is available;
  1394 
  1395 * In ZF, integer numerals now denote two's-complement binary integers.
  1396 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  1397 
  1398 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  1399 of the Axiom of Choice;
  1400 
  1401 
  1402 
  1403 New in Isabelle94-2
  1404 -------------------
  1405 
  1406 * Significantly faster resolution;
  1407 
  1408 * the different sections in a .thy file can now be mixed and repeated
  1409 freely;
  1410 
  1411 * Database of theorems for FOL, HOL and ZF.  New
  1412 commands including qed, qed_goal and bind_thm store theorems in the database.
  1413 
  1414 * Simple database queries: return a named theorem (get_thm) or all theorems of
  1415 a given theory (thms_of), or find out what theory a theorem was proved in
  1416 (theory_of_thm);
  1417 
  1418 * Bugs fixed in the inductive definition and datatype packages;
  1419 
  1420 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  1421 and HOL_dup_cs obsolete;
  1422 
  1423 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  1424 have been removed;
  1425 
  1426 * Simpler definition of function space in ZF;
  1427 
  1428 * new results about cardinal and ordinal arithmetic in ZF;
  1429 
  1430 * 'subtype' facility in HOL for introducing new types as subsets of existing
  1431 types;
  1432 
  1433 
  1434 $Id$