NEWS
author wenzelm
Thu Nov 23 21:29:35 2000 +0100 (2000-11-23)
changeset 10514 3db037155f0e
parent 10474 25caae39bd7a
child 10547 efaba354b7f1
permissions -rw-r--r--
* HOL: syntax or "abs";
     1 
     2 Isabelle NEWS -- history user-relevant changes
     3 ==============================================
     4 
     5 *** Overview of INCOMPATIBILITIES ***
     6 
     7 * HOL: induct renamed to lfp_induct;
     8 
     9 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
    10 
    11 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
    12 
    13 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
    14 consequence, it is no longer monotonic wrt. the local goal context
    15 (which is now passed through the inductive cases);
    16 
    17 
    18 *** Document preparation ***
    19 
    20 * improved isabelle style files; more abstract symbol implementation
    21 (should now use \isamath{...} and \isatext{...} in custom symbol
    22 definitions);
    23 
    24 * support sub/super scripts (for single symbols only), input syntax is
    25 like this: "A\<^sup>*" or "A\<^sup>\<star>";
    26 
    27 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals state;
    28 Note that presentation of goal states does not conform to actual
    29 human-readable proof documents.  Please do not include goal states
    30 into document output unless you really know what you are doing!
    31 
    32 
    33 *** Isar ***
    34 
    35 * Pure: assumption method (an implicit finishing) now handles actual
    36 rules as well;
    37 
    38 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
    39 initial goal, declare "that" only as Pure intro (only for single
    40 steps); the "that" rule assumption may now be involved in implicit
    41 finishing, thus ".." becomes a feasible for trivial obtains;
    42 
    43 * Pure: default proof step now includes 'intro_classes'; thus trivial
    44 instance proofs may be performed by "..";
    45 
    46 * Pure: ?thesis / ?this / "..." now work for pure meta-level
    47 statements as well;
    48 
    49 * HOL: improved method 'induct' --- now handles non-atomic goals
    50 (potential INCOMPATIBILITY); tuned error handling;
    51 
    52 
    53 *** HOL ***
    54 
    55 * HOL/Library: a collection of generic theories to be used together
    56 with main HOL; the theory loader path already includes this directory
    57 by default; the following existing theories have been moved here:
    58 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
    59 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
    60 
    61 * HOL basics: added overloaded operations "inverse" and "divide"
    62 (infix "/"), syntax for generic "abs" operation;
    63 
    64 * HOL/typedef: simplified package, provide more useful rules (see also
    65 HOL/subset.thy);
    66 
    67 
    68 *** CTT ***
    69 
    70 * CTT: x-symbol support for Pi, Sigma, -->, : (membership)
    71   note that "lam" is displayed as TWO lambda-symbols
    72 
    73 * CTT: theory Main now available, containing everything
    74 (that is, Bool and Arith) 
    75 
    76 *** General ***
    77 
    78 * Provers: fast_tac (and friends) now handle actual object-logic rules
    79 as assumptions as well;
    80 
    81 
    82 
    83 New in Isabelle99-1 (October 2000)
    84 ----------------------------------
    85 
    86 *** Overview of INCOMPATIBILITIES ***
    87 
    88 * HOL: simplification of natural numbers is much changed; to partly
    89 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
    90 issue the following ML commands:
    91 
    92   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
    93   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
    94 
    95 * HOL: simplification no longer dives into case-expressions; this is
    96 controlled by "t.weak_case_cong" for each datatype t;
    97 
    98 * HOL: nat_less_induct renamed to less_induct;
    99 
   100 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
   101 fixsome to patch .thy and .ML sources automatically;
   102 
   103   select_equality  -> some_equality
   104   select_eq_Ex     -> some_eq_ex
   105   selectI2EX       -> someI2_ex
   106   selectI2         -> someI2
   107   selectI          -> someI
   108   select1_equality -> some1_equality
   109   Eps_sym_eq       -> some_sym_eq_trivial
   110   Eps_eq           -> some_eq_trivial
   111 
   112 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
   113 
   114 * HOL: removed obsolete theorem binding expand_if (refer to split_if
   115 instead);
   116 
   117 * HOL: the recursion equations generated by 'recdef' are now called
   118 f.simps instead of f.rules;
   119 
   120 * HOL: qed_spec_mp now also handles bounded ALL as well;
   121 
   122 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
   123 sometimes be needed;
   124 
   125 * HOL: the constant for "f``x" is now "image" rather than "op ``";
   126 
   127 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
   128 
   129 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
   130 product is now "<*>" instead of "Times"; the lexicographic product is
   131 now "<*lex*>" instead of "**";
   132 
   133 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
   134 of main HOL, but was unused); better use HOL's datatype package;
   135 
   136 * HOL: removed "symbols" syntax for constant "override" of theory Map;
   137 the old syntax may be recovered as follows:
   138 
   139   syntax (symbols)
   140     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
   141       (infixl "\\<oplus>" 100)
   142 
   143 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   144 
   145 * HOL/ML: even fewer consts are declared as global (see theories Ord,
   146 Lfp, Gfp, WF); this only affects ML packages that refer to const names
   147 internally;
   148 
   149 * HOL and ZF: syntax for quotienting wrt an equivalence relation
   150 changed from A/r to A//r;
   151 
   152 * ZF: new treatment of arithmetic (nat & int) may break some old
   153 proofs;
   154 
   155 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
   156 rulify -> rule_format, elimify -> elim_format, ...);
   157 
   158 * Isar/Provers: intro/elim/dest attributes changed; renamed
   159 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
   160 should have to change intro!! to intro? only); replaced "delrule" by
   161 "rule del";
   162 
   163 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
   164 
   165 * Provers: strengthened force_tac by using new first_best_tac;
   166 
   167 * LaTeX document preparation: several changes of isabelle.sty (see
   168 lib/texinputs);
   169 
   170 
   171 *** Document preparation ***
   172 
   173 * formal comments (text blocks etc.) in new-style theories may now
   174 contain antiquotations of thm/prop/term/typ/text to be presented
   175 according to latex print mode; concrete syntax is like this:
   176 @{term[show_types] "f(x) = a + x"};
   177 
   178 * isatool mkdir provides easy setup of Isabelle session directories,
   179 including proper document sources;
   180 
   181 * generated LaTeX sources are now deleted after successful run
   182 (isatool document -c); may retain a copy somewhere else via -D option
   183 of isatool usedir;
   184 
   185 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
   186 style files, achieving self-contained LaTeX sources and simplifying
   187 LaTeX debugging;
   188 
   189 * old-style theories now produce (crude) LaTeX output as well;
   190 
   191 * browser info session directories are now self-contained (may be put
   192 on WWW server seperately); improved graphs of nested sessions; removed
   193 graph for 'all sessions';
   194 
   195 * several improvements in isabelle style files; \isabellestyle{it}
   196 produces fake math mode output; \isamarkupheader is now \section by
   197 default; see lib/texinputs/isabelle.sty etc.;
   198 
   199 
   200 *** Isar ***
   201 
   202 * Isar/Pure: local results and corresponding term bindings are now
   203 subject to Hindley-Milner polymorphism (similar to ML); this
   204 accommodates incremental type-inference very nicely;
   205 
   206 * Isar/Pure: new derived language element 'obtain' supports
   207 generalized existence reasoning;
   208 
   209 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
   210 support accumulation of results, without applying any rules yet;
   211 useful to collect intermediate results without explicit name
   212 references, and for use with transitivity rules with more than 2
   213 premises;
   214 
   215 * Isar/Pure: scalable support for case-analysis type proofs: new
   216 'case' language element refers to local contexts symbolically, as
   217 produced by certain proof methods; internally, case names are attached
   218 to theorems as "tags";
   219 
   220 * Isar/Pure: theory command 'hide' removes declarations from
   221 class/type/const name spaces;
   222 
   223 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
   224 indicate potential overloading;
   225 
   226 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
   227 
   228 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
   229 "{a,b,c}" instead of {a,b,c};
   230 
   231 * Isar/Pure now provides its own version of intro/elim/dest
   232 attributes; useful for building new logics, but beware of confusion
   233 with the version in Provers/classical;
   234 
   235 * Isar/Pure: the local context of (non-atomic) goals is provided via
   236 case name 'antecedent';
   237 
   238 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
   239 to the current context is now done automatically);
   240 
   241 * Isar/Pure: theory command 'method_setup' provides a simple interface
   242 for definining proof methods in ML;
   243 
   244 * Isar/Provers: intro/elim/dest attributes changed; renamed
   245 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
   246 most cases, one should have to change intro!! to intro? only);
   247 replaced "delrule" by "rule del";
   248 
   249 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
   250 'symmetric' attribute (the latter supercedes [RS sym]);
   251 
   252 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
   253 method modifier); 'simp' method: 'only:' modifier removes loopers as
   254 well (including splits);
   255 
   256 * Isar/Provers: Simplifier and Classical methods now support all kind
   257 of modifiers used in the past, including 'cong', 'iff', etc.
   258 
   259 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
   260 of Simplifier and Classical reasoner);
   261 
   262 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
   263 now support named cases; major packages (inductive, datatype, primrec,
   264 recdef) support case names and properly name parameters;
   265 
   266 * Isar/HOL: new transitivity rules for substitution in inequalities --
   267 monotonicity conditions are extracted to be proven at end of
   268 calculations;
   269 
   270 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
   271 method anyway;
   272 
   273 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
   274 split_if split_if_asm; datatype package provides theorems foo.splits =
   275 foo.split foo.split_asm for each datatype;
   276 
   277 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
   278 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
   279 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
   280 use "(cases (simplified))" method in proper proof texts);
   281 
   282 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
   283 
   284 * Isar: names of theorems etc. may be natural numbers as well;
   285 
   286 * Isar: 'pr' command: optional arguments for goals_limit and
   287 ProofContext.prems_limit; no longer prints theory contexts, but only
   288 proof states;
   289 
   290 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
   291 additional print modes to be specified; e.g. "pr(latex)" will print
   292 proof state according to the Isabelle LaTeX style;
   293 
   294 * Isar: improved support for emulating tactic scripts, including proof
   295 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
   296 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
   297 (for HOL datatypes);
   298 
   299 * Isar: simplified (more robust) goal selection of proof methods: 1st
   300 goal, all goals, or explicit goal specifier (tactic emulation); thus
   301 'proof method scripts' have to be in depth-first order;
   302 
   303 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
   304 
   305 * Isar: removed 'help' command, which hasn't been too helpful anyway;
   306 should instead use individual commands for printing items
   307 (print_commands, print_methods etc.);
   308 
   309 * Isar: added 'nothing' --- the empty list of theorems;
   310 
   311 
   312 *** HOL ***
   313 
   314 * HOL/MicroJava: formalization of a fragment of Java, together with a
   315 corresponding virtual machine and a specification of its bytecode
   316 verifier and a lightweight bytecode verifier, including proofs of
   317 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
   318 Cornelia Pusch (see also the homepage of project Bali at
   319 http://isabelle.in.tum.de/Bali/);
   320 
   321 * HOL/Algebra: new theory of rings and univariate polynomials, by
   322 Clemens Ballarin;
   323 
   324 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
   325 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
   326 Rasmussen;
   327 
   328 * HOL/Lattice: fundamental concepts of lattice theory and order
   329 structures, including duals, properties of bounds versus algebraic
   330 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
   331 Theorem for complete lattices etc.; may also serve as a demonstration
   332 for abstract algebraic reasoning using axiomatic type classes, and
   333 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
   334 
   335 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
   336 von Oheimb;
   337 
   338 * HOL/IMPP: extension of IMP with local variables and mutually
   339 recursive procedures, by David von Oheimb;
   340 
   341 * HOL/Lambda: converted into new-style theory and document;
   342 
   343 * HOL/ex/Multiquote: example of multiple nested quotations and
   344 anti-quotations -- basically a generalized version of de-Bruijn
   345 representation; very useful in avoiding lifting of operations;
   346 
   347 * HOL/record: added general record equality rule to simpset; fixed
   348 select-update simplification procedure to handle extended records as
   349 well; admit "r" as field name;
   350 
   351 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
   352 other numeric types and also as the identity of groups, rings, etc.;
   353 
   354 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
   355 Types nat and int belong to this axclass;
   356 
   357 * HOL: greatly improved simplification involving numerals of type nat, int, real:
   358    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
   359    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
   360   two terms #m*u and #n*u are replaced by #(m+n)*u
   361     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
   362   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
   363     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
   364 
   365 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
   366 powerful prover for predicate logic but knows nothing of clasets; see
   367 ex/mesontest.ML and ex/mesontest2.ML for example applications;
   368 
   369 * HOL: new version of "case_tac" subsumes both boolean case split and
   370 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
   371 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
   372 
   373 * HOL: simplification no longer dives into case-expressions: only the
   374 selector expression is simplified, but not the remaining arms; to
   375 enable full simplification of case-expressions for datatype t, you may
   376 remove t.weak_case_cong from the simpset, either globally (Delcongs
   377 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
   378 
   379 * HOL/recdef: the recursion equations generated by 'recdef' for
   380 function 'f' are now called f.simps instead of f.rules; if all
   381 termination conditions are proved automatically, these simplification
   382 rules are added to the simpset, as in primrec; rules may be named
   383 individually as well, resulting in a separate list of theorems for
   384 each equation;
   385 
   386 * HOL/While is a new theory that provides a while-combinator. It
   387 permits the definition of tail-recursive functions without the
   388 provision of a termination measure. The latter is necessary once the
   389 invariant proof rule for while is applied.
   390 
   391 * HOL: new (overloaded) notation for the set of elements below/above
   392 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
   393 
   394 * HOL: theorems impI, allI, ballI bound as "strip";
   395 
   396 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
   397 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
   398 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
   399 
   400 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   401 
   402 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
   403 main HOL, but was unused);
   404 
   405 * HOL: fewer consts declared as global (e.g. have to refer to
   406 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
   407 
   408 * HOL: tuned AST representation of nested pairs, avoiding bogus output
   409 in case of overlap with user translations (e.g. judgements over
   410 tuples); (note that the underlying logical represenation is still
   411 bogus);
   412 
   413 
   414 *** ZF ***
   415 
   416 * ZF: simplification automatically cancels common terms in arithmetic
   417 expressions over nat and int;
   418 
   419 * ZF: new treatment of nat to minimize type-checking: all operators
   420 coerce their operands to a natural number using the function natify,
   421 making the algebraic laws unconditional;
   422 
   423 * ZF: as above, for int: operators coerce their operands to an integer
   424 using the function intify;
   425 
   426 * ZF: the integer library now contains many of the usual laws for the
   427 orderings, including $<=, and monotonicity laws for $+ and $*;
   428 
   429 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
   430 simplification;
   431 
   432 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
   433 to the simplifier and classical reasoner simultaneously;
   434 
   435 
   436 *** General ***
   437 
   438 * Provers: blast_tac now handles actual object-logic rules as
   439 assumptions; note that auto_tac uses blast_tac internally as well;
   440 
   441 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
   442 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
   443 
   444 * Provers: delrules now handles destruct rules as well (no longer need
   445 explicit make_elim);
   446 
   447 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
   448   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   449 use instead the strong form,
   450   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
   451 in HOL, FOL and ZF the function cla_make_elim will create such rules
   452 from destruct-rules;
   453 
   454 * Provers: Simplifier.easy_setup provides a fast path to basic
   455 Simplifier setup for new object-logics;
   456 
   457 * Pure: AST translation rules no longer require constant head on LHS;
   458 
   459 * Pure: improved name spaces: ambiguous output is qualified; support
   460 for hiding of names;
   461 
   462 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
   463 XSYMBOL_HOME; no longer need to do manual configuration in most
   464 situations;
   465 
   466 * system: compression of ML heaps images may now be controlled via -c
   467 option of isabelle and isatool usedir (currently only observed by
   468 Poly/ML);
   469 
   470 * system: isatool installfonts may handle X-Symbol fonts as well (very
   471 useful for remote X11);
   472 
   473 * system: provide TAGS file for Isabelle sources;
   474 
   475 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
   476 order;
   477 
   478 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
   479 timing flag supersedes proof_timing and Toplevel.trace;
   480 
   481 * ML: new combinators |>> and |>>> for incremental transformations
   482 with secondary results (e.g. certain theory extensions):
   483 
   484 * ML: PureThy.add_defs gets additional argument to indicate potential
   485 overloading (usually false);
   486 
   487 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
   488 results;
   489 
   490 
   491 
   492 New in Isabelle99 (October 1999)
   493 --------------------------------
   494 
   495 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   496 
   497 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
   498 are no longer simplified.  (This allows the simplifier to unfold recursive
   499 functional programs.)  To restore the old behaviour, declare
   500 
   501     Delcongs [if_weak_cong];
   502 
   503 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
   504 complement;
   505 
   506 * HOL: the predicate "inj" is now defined by translation to "inj_on";
   507 
   508 * HOL/datatype: mutual_induct_tac no longer exists --
   509   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
   510 
   511 * HOL/typedef: fixed type inference for representing set; type
   512 arguments now have to occur explicitly on the rhs as type constraints;
   513 
   514 * ZF: The con_defs part of an inductive definition may no longer refer
   515 to constants declared in the same theory;
   516 
   517 * HOL, ZF: the function mk_cases, generated by the inductive
   518 definition package, has lost an argument.  To simplify its result, it
   519 uses the default simpset instead of a supplied list of theorems.
   520 
   521 * HOL/List: the constructors of type list are now Nil and Cons;
   522 
   523 * Simplifier: the type of the infix ML functions
   524         setSSolver addSSolver setSolver addSolver
   525 is now  simpset * solver -> simpset  where `solver' is a new abstract type
   526 for packaging solvers. A solver is created via
   527         mk_solver: string -> (thm list -> int -> tactic) -> solver
   528 where the string argument is only a comment.
   529 
   530 
   531 *** Proof tools ***
   532 
   533 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
   534 decision procedure for linear arithmetic. Currently it is used for
   535 types `nat', `int', and `real' in HOL (see below); it can, should and
   536 will be instantiated for other types and logics as well.
   537 
   538 * The simplifier now accepts rewrite rules with flexible heads, eg
   539      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
   540   They are applied like any rule with a non-pattern lhs, i.e. by first-order
   541   matching.
   542 
   543 
   544 *** General ***
   545 
   546 * New Isabelle/Isar subsystem provides an alternative to traditional
   547 tactical theorem proving; together with the ProofGeneral/isar user
   548 interface it offers an interactive environment for developing human
   549 readable proof documents (Isar == Intelligible semi-automated
   550 reasoning); for further information see isatool doc isar-ref,
   551 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
   552 
   553 * improved and simplified presentation of theories: better HTML markup
   554 (including colors), graph views in several sizes; isatool usedir now
   555 provides a proper interface for user theories (via -P option); actual
   556 document preparation based on (PDF)LaTeX is available as well (for
   557 new-style theories only); see isatool doc system for more information;
   558 
   559 * native support for Proof General, both for classic Isabelle and
   560 Isabelle/Isar;
   561 
   562 * ML function thm_deps visualizes dependencies of theorems and lemmas,
   563 using the graph browser tool;
   564 
   565 * Isabelle manuals now also available as PDF;
   566 
   567 * theory loader rewritten from scratch (may not be fully
   568 bug-compatible); old loadpath variable has been replaced by show_path,
   569 add_path, del_path, reset_path functions; new operations such as
   570 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
   571 isatool doc ref);
   572 
   573 * improved isatool install: option -k creates KDE application icon,
   574 option -p DIR installs standalone binaries;
   575 
   576 * added ML_PLATFORM setting (useful for cross-platform installations);
   577 more robust handling of platform specific ML images for SML/NJ;
   578 
   579 * the settings environment is now statically scoped, i.e. it is never
   580 created again in sub-processes invoked from isabelle, isatool, or
   581 Isabelle;
   582 
   583 * path element specification '~~' refers to '$ISABELLE_HOME';
   584 
   585 * in locales, the "assumes" and "defines" parts may be omitted if
   586 empty;
   587 
   588 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
   589 long arrows);
   590 
   591 * new print_mode "HTML";
   592 
   593 * new flag show_tags controls display of tags of theorems (which are
   594 basically just comments that may be attached by some tools);
   595 
   596 * Isamode 2.6 requires patch to accomodate change of Isabelle font
   597 mode and goal output format:
   598 
   599 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
   600 244c244
   601 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
   602 ---
   603 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
   604 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
   605 181c181
   606 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
   607 ---
   608 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
   609 
   610 * function bind_thms stores lists of theorems (cf. bind_thm);
   611 
   612 * new shorthand tactics ftac, eatac, datac, fatac;
   613 
   614 * qed (and friends) now accept "" as result name; in that case the
   615 theorem is not stored, but proper checks and presentation of the
   616 result still apply;
   617 
   618 * theorem database now also indexes constants "Trueprop", "all",
   619 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
   620 
   621 
   622 *** HOL ***
   623 
   624 ** HOL arithmetic **
   625 
   626 * There are now decision procedures for linear arithmetic over nat and
   627 int:
   628 
   629 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
   630 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
   631 are treated as atomic; subformulae not involving type `nat' or `int'
   632 are ignored; quantified subformulae are ignored unless they are
   633 positive universal or negative existential. The tactic has to be
   634 invoked by hand and can be a little bit slow. In particular, the
   635 running time is exponential in the number of occurrences of `min' and
   636 `max', and `-' on `nat'.
   637 
   638 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
   639 (negated) (in)equalities among the premises and the conclusion into
   640 account (i.e. no compound formulae) and does not know about `min' and
   641 `max', and `-' on `nat'. It is fast and is used automatically by the
   642 simplifier.
   643 
   644 NB: At the moment, these decision procedures do not cope with mixed
   645 nat/int formulae where the two parts interact, such as `m < n ==>
   646 int(m) < int(n)'.
   647 
   648 * HOL/Numeral provides a generic theory of numerals (encoded
   649 efficiently as bit strings); setup for types nat/int/real is in place;
   650 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
   651 int, existing theories and proof scripts may require a few additional
   652 type constraints;
   653 
   654 * integer division and remainder can now be performed on constant
   655 arguments;
   656 
   657 * many properties of integer multiplication, division and remainder
   658 are now available;
   659 
   660 * An interface to the Stanford Validity Checker (SVC) is available through the
   661 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
   662 are proved automatically.  SVC must be installed separately, and its results
   663 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
   664 invocation of the underlying oracle).  For SVC see
   665   http://verify.stanford.edu/SVC
   666 
   667 * IsaMakefile: the HOL-Real target now builds an actual image;
   668 
   669 
   670 ** HOL misc **
   671 
   672 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
   673 (in Isabelle/Isar) -- by Gertrud Bauer;
   674 
   675 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
   676 analysis for assembly languages with subtypes;
   677 
   678 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
   679 -- avoids syntactic ambiguities and treats state, transition, and
   680 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
   681 changed syntax and (many) tactics;
   682 
   683 * HOL/inductive: Now also handles more general introduction rules such
   684   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
   685   theorems are now maintained within the theory (maintained via the
   686   "mono" attribute);
   687 
   688 * HOL/datatype: Now also handles arbitrarily branching datatypes
   689   (using function types) such as
   690 
   691   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
   692 
   693 * HOL/record: record_simproc (part of the default simpset) takes care
   694 of selectors applied to updated records; record_split_tac is no longer
   695 part of the default claset; update_defs may now be removed from the
   696 simpset in many cases; COMPATIBILITY: old behavior achieved by
   697 
   698   claset_ref () := claset() addSWrapper record_split_wrapper;
   699   Delsimprocs [record_simproc]
   700 
   701 * HOL/typedef: fixed type inference for representing set; type
   702 arguments now have to occur explicitly on the rhs as type constraints;
   703 
   704 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
   705 names rather than an ML expression;
   706 
   707 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
   708 supplied later.  Program schemes can be defined, such as
   709     "While B C s = (if B s then While B C (C s) else s)"
   710 where the well-founded relation can be chosen after B and C have been given.
   711 
   712 * HOL/List: the constructors of type list are now Nil and Cons;
   713 INCOMPATIBILITY: while [] and infix # syntax is still there, of
   714 course, ML tools referring to List.list.op # etc. have to be adapted;
   715 
   716 * HOL_quantifiers flag superseded by "HOL" print mode, which is
   717 disabled by default; run isabelle with option -m HOL to get back to
   718 the original Gordon/HOL-style output;
   719 
   720 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
   721 ALL x<=y. P, EX x<y. P, EX x<=y. P;
   722 
   723 * HOL basic syntax simplified (more orthogonal): all variants of
   724 All/Ex now support plain / symbolic / HOL notation; plain syntax for
   725 Eps operator is provided as well: "SOME x. P[x]";
   726 
   727 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
   728 
   729 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
   730 thus available for user theories;
   731 
   732 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
   733 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
   734 time;
   735 
   736 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
   737 several times and then mp;
   738 
   739 
   740 *** LK ***
   741 
   742 * the notation <<...>> is now available as a notation for sequences of
   743 formulas;
   744 
   745 * the simplifier is now installed
   746 
   747 * the axiom system has been generalized (thanks to Soren Heilmann)
   748 
   749 * the classical reasoner now has a default rule database
   750 
   751 
   752 *** ZF ***
   753 
   754 * new primrec section allows primitive recursive functions to be given
   755 directly (as in HOL) over datatypes and the natural numbers;
   756 
   757 * new tactics induct_tac and exhaust_tac for induction (or case
   758 analysis) over datatypes and the natural numbers;
   759 
   760 * the datatype declaration of type T now defines the recursor T_rec;
   761 
   762 * simplification automatically does freeness reasoning for datatype
   763 constructors;
   764 
   765 * automatic type-inference, with AddTCs command to insert new
   766 type-checking rules;
   767 
   768 * datatype introduction rules are now added as Safe Introduction rules
   769 to the claset;
   770 
   771 * the syntax "if P then x else y" is now available in addition to
   772 if(P,x,y);
   773 
   774 
   775 *** Internal programming interfaces ***
   776 
   777 * tuned simplifier trace output; new flag debug_simp;
   778 
   779 * structures Vartab / Termtab (instances of TableFun) offer efficient
   780 tables indexed by indexname_ord / term_ord (compatible with aconv);
   781 
   782 * AxClass.axclass_tac lost the theory argument;
   783 
   784 * tuned current_goals_markers semantics: begin / end goal avoids
   785 printing empty lines;
   786 
   787 * removed prs and prs_fn hook, which was broken because it did not
   788 include \n in its semantics, forcing writeln to add one
   789 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
   790 string -> unit if you really want to output text without newline;
   791 
   792 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
   793 plain output, interface builders may have to enable 'isabelle_font'
   794 mode to get Isabelle font glyphs as before;
   795 
   796 * refined token_translation interface; INCOMPATIBILITY: output length
   797 now of type real instead of int;
   798 
   799 * theory loader actions may be traced via new ThyInfo.add_hook
   800 interface (see src/Pure/Thy/thy_info.ML); example application: keep
   801 your own database of information attached to *whole* theories -- as
   802 opposed to intra-theory data slots offered via TheoryDataFun;
   803 
   804 * proper handling of dangling sort hypotheses (at last!);
   805 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
   806 extra sort hypotheses that can be witnessed from the type signature;
   807 the force_strip_shyps flag is gone, any remaining shyps are simply
   808 left in the theorem (with a warning issued by strip_shyps_warning);
   809 
   810 
   811 
   812 New in Isabelle98-1 (October 1998)
   813 ----------------------------------
   814 
   815 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   816 
   817 * several changes of automated proof tools;
   818 
   819 * HOL: major changes to the inductive and datatype packages, including
   820 some minor incompatibilities of theory syntax;
   821 
   822 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
   823 called `inj_on';
   824 
   825 * HOL: removed duplicate thms in Arith:
   826   less_imp_add_less  should be replaced by  trans_less_add1
   827   le_imp_add_le      should be replaced by  trans_le_add1
   828 
   829 * HOL: unary minus is now overloaded (new type constraints may be
   830 required);
   831 
   832 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
   833 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
   834 now taken as an integer constant.
   835 
   836 * Pure: ML function 'theory_of' renamed to 'theory';
   837 
   838 
   839 *** Proof tools ***
   840 
   841 * Simplifier:
   842   1. Asm_full_simp_tac is now more aggressive.
   843      1. It will sometimes reorient premises if that increases their power to
   844         simplify.
   845      2. It does no longer proceed strictly from left to right but may also
   846         rotate premises to achieve further simplification.
   847      For compatibility reasons there is now Asm_lr_simp_tac which is like the
   848      old Asm_full_simp_tac in that it does not rotate premises.
   849   2. The simplifier now knows a little bit about nat-arithmetic.
   850 
   851 * Classical reasoner: wrapper mechanism for the classical reasoner now
   852 allows for selected deletion of wrappers, by introduction of names for
   853 wrapper functionals.  This implies that addbefore, addSbefore,
   854 addaltern, and addSaltern now take a pair (name, tactic) as argument,
   855 and that adding two tactics with the same name overwrites the first
   856 one (emitting a warning).
   857   type wrapper = (int -> tactic) -> (int -> tactic)
   858   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
   859   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
   860   delWrapper, delSWrapper: claset *  string            -> claset
   861   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
   862 
   863 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
   864 semantics; addbefore now affects only the unsafe part of step_tac
   865 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
   866 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
   867 by Force_tac;
   868 
   869 * Classical reasoner: setwrapper to setWrapper and compwrapper to
   870 compWrapper; added safe wrapper (and access functions for it);
   871 
   872 * HOL/split_all_tac is now much faster and fails if there is nothing
   873 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
   874 and the names of the automatically generated variables have changed.
   875 split_all_tac has moved within claset() from unsafe wrappers to safe
   876 wrappers, which means that !!-bound variables are split much more
   877 aggressively, and safe_tac and clarify_tac now split such variables.
   878 If this splitting is not appropriate, use delSWrapper "split_all_tac".
   879 Note: the same holds for record_split_tac, which does the job of
   880 split_all_tac for record fields.
   881 
   882 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
   883 permanently to the default simpset using Addsplits just like
   884 Addsimps. They can be removed via Delsplits just like
   885 Delsimps. Lower-case versions are also available.
   886 
   887 * HOL/Simplifier: The rule split_if is now part of the default
   888 simpset. This means that the simplifier will eliminate all occurrences
   889 of if-then-else in the conclusion of a goal. To prevent this, you can
   890 either remove split_if completely from the default simpset by
   891 `Delsplits [split_if]' or remove it in a specific call of the
   892 simplifier using `... delsplits [split_if]'.  You can also add/delete
   893 other case splitting rules to/from the default simpset: every datatype
   894 generates suitable rules `split_t_case' and `split_t_case_asm' (where
   895 t is the name of the datatype).
   896 
   897 * Classical reasoner / Simplifier combination: new force_tac (and
   898 derivatives Force_tac, force) combines rewriting and classical
   899 reasoning (and whatever other tools) similarly to auto_tac, but is
   900 aimed to solve the given subgoal completely.
   901 
   902 
   903 *** General ***
   904 
   905 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
   906 and `goalw': the theory is no longer needed as an explicit argument -
   907 the current theory context is used; assumptions are no longer returned
   908 at the ML-level unless one of them starts with ==> or !!; it is
   909 recommended to convert to these new commands using isatool fixgoal
   910 (backup your sources first!);
   911 
   912 * new top-level commands 'thm' and 'thms' for retrieving theorems from
   913 the current theory context, and 'theory' to lookup stored theories;
   914 
   915 * new theory section 'locale' for declaring constants, assumptions and
   916 definitions that have local scope;
   917 
   918 * new theory section 'nonterminals' for purely syntactic types;
   919 
   920 * new theory section 'setup' for generic ML setup functions
   921 (e.g. package initialization);
   922 
   923 * the distribution now includes Isabelle icons: see
   924 lib/logo/isabelle-{small,tiny}.xpm;
   925 
   926 * isatool install - install binaries with absolute references to
   927 ISABELLE_HOME/bin;
   928 
   929 * isatool logo -- create instances of the Isabelle logo (as EPS);
   930 
   931 * print mode 'emacs' reserved for Isamode;
   932 
   933 * support multiple print (ast) translations per constant name;
   934 
   935 * theorems involving oracles are now printed with a suffixed [!];
   936 
   937 
   938 *** HOL ***
   939 
   940 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
   941 
   942 * HOL/inductive package reorganized and improved: now supports mutual
   943 definitions such as
   944 
   945   inductive EVEN ODD
   946     intrs
   947       null "0 : EVEN"
   948       oddI "n : EVEN ==> Suc n : ODD"
   949       evenI "n : ODD ==> Suc n : EVEN"
   950 
   951 new theorem list "elims" contains an elimination rule for each of the
   952 recursive sets; inductive definitions now handle disjunctive premises
   953 correctly (also ZF);
   954 
   955 INCOMPATIBILITIES: requires Inductive as an ancestor; component
   956 "mutual_induct" no longer exists - the induction rule is always
   957 contained in "induct";
   958 
   959 
   960 * HOL/datatype package re-implemented and greatly improved: now
   961 supports mutually recursive datatypes such as
   962 
   963   datatype
   964     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
   965             | SUM ('a aexp) ('a aexp)
   966             | DIFF ('a aexp) ('a aexp)
   967             | NUM 'a
   968   and
   969     'a bexp = LESS ('a aexp) ('a aexp)
   970             | AND ('a bexp) ('a bexp)
   971             | OR ('a bexp) ('a bexp)
   972 
   973 as well as indirectly recursive datatypes such as
   974 
   975   datatype
   976     ('a, 'b) term = Var 'a
   977                   | App 'b ((('a, 'b) term) list)
   978 
   979 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
   980 induction on mutually / indirectly recursive datatypes.
   981 
   982 Primrec equations are now stored in theory and can be accessed via
   983 <function_name>.simps.
   984 
   985 INCOMPATIBILITIES:
   986 
   987   - Theories using datatypes must now have theory Datatype as an
   988     ancestor.
   989   - The specific <typename>.induct_tac no longer exists - use the
   990     generic induct_tac instead.
   991   - natE has been renamed to nat.exhaust - use exhaust_tac
   992     instead of res_inst_tac ... natE. Note that the variable
   993     names in nat.exhaust differ from the names in natE, this
   994     may cause some "fragile" proofs to fail.
   995   - The theorems split_<typename>_case and split_<typename>_case_asm
   996     have been renamed to <typename>.split and <typename>.split_asm.
   997   - Since default sorts of type variables are now handled correctly,
   998     some datatype definitions may have to be annotated with explicit
   999     sort constraints.
  1000   - Primrec definitions no longer require function name and type
  1001     of recursive argument.
  1002 
  1003 Consider using isatool fixdatatype to adapt your theories and proof
  1004 scripts to the new package (backup your sources first!).
  1005 
  1006 
  1007 * HOL/record package: considerably improved implementation; now
  1008 includes concrete syntax for record types, terms, updates; theorems
  1009 for surjective pairing and splitting !!-bound record variables; proof
  1010 support is as follows:
  1011 
  1012   1) standard conversions (selectors or updates applied to record
  1013 constructor terms) are part of the standard simpset;
  1014 
  1015   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  1016 made part of standard simpset and claset via addIffs;
  1017 
  1018   3) a tactic for record field splitting (record_split_tac) is part of
  1019 the standard claset (addSWrapper);
  1020 
  1021 To get a better idea about these rules you may retrieve them via
  1022 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  1023 the name of your record type.
  1024 
  1025 The split tactic 3) conceptually simplifies by the following rule:
  1026 
  1027   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  1028 
  1029 Thus any record variable that is bound by meta-all will automatically
  1030 blow up into some record constructor term, consequently the
  1031 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  1032 solve record problems automatically.
  1033 
  1034 
  1035 * reorganized the main HOL image: HOL/Integ and String loaded by
  1036 default; theory Main includes everything;
  1037 
  1038 * automatic simplification of integer sums and comparisons, using cancellation;
  1039 
  1040 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  1041 
  1042 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  1043 
  1044 * many new identities for unions, intersections, set difference, etc.;
  1045 
  1046 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  1047 called split_if, split_split, split_sum_case and split_nat_case (to go
  1048 with add/delsplits);
  1049 
  1050 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  1051 (?x::unit) = (); this is made part of the default simpset, which COULD
  1052 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  1053 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  1054 unit_abs_eta_conv is added in order to counter the effect of
  1055 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  1056 %u.f();
  1057 
  1058 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  1059 makes more sense);
  1060 
  1061 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1062   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1063   disjointness reasoning but breaking a few old proofs.
  1064 
  1065 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  1066 to 'converse' from 'inverse' (for compatibility with ZF and some
  1067 literature);
  1068 
  1069 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  1070 the well-founded relation;
  1071 
  1072 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  1073     Compl A.  The "Compl" syntax remains available as input syntax for this
  1074     release ONLY.
  1075 
  1076 * HOL/Update: new theory of function updates:
  1077     f(a:=b) == %x. if x=a then b else f x
  1078 may also be iterated as in f(a:=b,c:=d,...);
  1079 
  1080 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  1081 
  1082 * HOL/List:
  1083   - new function list_update written xs[i:=v] that updates the i-th
  1084     list position. May also be iterated as in xs[i:=a,j:=b,...].
  1085   - new function `upt' written [i..j(] which generates the list
  1086     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  1087     bound write [i..j], which is a shorthand for [i..j+1(].
  1088   - new lexicographic orderings and corresponding wellfoundedness theorems.
  1089 
  1090 * HOL/Arith:
  1091   - removed 'pred' (predecessor) function;
  1092   - generalized some theorems about n-1;
  1093   - many new laws about "div" and "mod";
  1094   - new laws about greatest common divisors (see theory ex/Primes);
  1095 
  1096 * HOL/Relation: renamed the relational operator r^-1 "converse"
  1097 instead of "inverse";
  1098 
  1099 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  1100   of the multiset ordering;
  1101 
  1102 * directory HOL/Real: a construction of the reals using Dedekind cuts
  1103   (not included by default);
  1104 
  1105 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  1106 
  1107 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  1108   programs, i.e. different program variables may have different types.
  1109 
  1110 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1111   [previously, this check worked only if the rewrite rule was unconditional]
  1112   Now rew can involve either definitions or equalities (either == or =).
  1113 
  1114 
  1115 *** ZF ***
  1116 
  1117 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  1118   only the theorems proved on ZF.ML;
  1119 
  1120 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1121   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1122   disjointness reasoning but breaking a few old proofs.
  1123 
  1124 * ZF/Update: new theory of function updates
  1125     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  1126   may also be iterated as in f(a:=b,c:=d,...);
  1127 
  1128 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  1129 
  1130 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1131   [previously, this check worked only if the rewrite rule was unconditional]
  1132   Now rew can involve either definitions or equalities (either == or =).
  1133 
  1134 * case_tac provided for compatibility with HOL
  1135     (like the old excluded_middle_tac, but with subgoals swapped)
  1136 
  1137 
  1138 *** Internal programming interfaces ***
  1139 
  1140 * Pure: several new basic modules made available for general use, see
  1141 also src/Pure/README;
  1142 
  1143 * improved the theory data mechanism to support encapsulation (data
  1144 kind name replaced by private Object.kind, acting as authorization
  1145 key); new type-safe user interface via functor TheoryDataFun; generic
  1146 print_data function becomes basically useless;
  1147 
  1148 * removed global_names compatibility flag -- all theory declarations
  1149 are qualified by default;
  1150 
  1151 * module Pure/Syntax now offers quote / antiquote translation
  1152 functions (useful for Hoare logic etc. with implicit dependencies);
  1153 see HOL/ex/Antiquote for an example use;
  1154 
  1155 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  1156 cterm -> thm;
  1157 
  1158 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  1159 subgoal;
  1160 
  1161 * Display.print_goals function moved to Locale.print_goals;
  1162 
  1163 * standard print function for goals supports current_goals_markers
  1164 variable for marking begin of proof, end of proof, start of goal; the
  1165 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  1166 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  1167 for example;
  1168 
  1169 
  1170 
  1171 New in Isabelle98 (January 1998)
  1172 --------------------------------
  1173 
  1174 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1175 
  1176 * changed lexical syntax of terms / types: dots made part of long
  1177 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  1178 
  1179 * simpset (and claset) reference variable replaced by functions
  1180 simpset / simpset_ref;
  1181 
  1182 * no longer supports theory aliases (via merge) and non-trivial
  1183 implicit merge of thms' signatures;
  1184 
  1185 * most internal names of constants changed due to qualified names;
  1186 
  1187 * changed Pure/Sequence interface (see Pure/seq.ML);
  1188 
  1189 
  1190 *** General Changes ***
  1191 
  1192 * hierachically structured name spaces (for consts, types, axms, thms
  1193 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  1194 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  1195 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  1196 long_names for fully qualified output names; NOTE: ML programs
  1197 (special tactics, packages etc.) referring to internal names may have
  1198 to be adapted to cope with fully qualified names; in case of severe
  1199 backward campatibility problems try setting 'global_names' at compile
  1200 time to have enrything declared within a flat name space; one may also
  1201 fine tune name declarations in theories via the 'global' and 'local'
  1202 section;
  1203 
  1204 * reimplemented the implicit simpset and claset using the new anytype
  1205 data filed in signatures; references simpset:simpset ref etc. are
  1206 replaced by functions simpset:unit->simpset and
  1207 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  1208 to patch your ML files accordingly;
  1209 
  1210 * HTML output now includes theory graph data for display with Java
  1211 applet or isatool browser; data generated automatically via isatool
  1212 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  1213 
  1214 * defs may now be conditional; improved rewrite_goals_tac to handle
  1215 conditional equations;
  1216 
  1217 * defs now admits additional type arguments, using TYPE('a) syntax;
  1218 
  1219 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  1220 creates a new theory node; implicit merge of thms' signatures is
  1221 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  1222 transfer:theory->thm->thm in (rare) cases;
  1223 
  1224 * improved handling of draft signatures / theories; draft thms (and
  1225 ctyps, cterms) are automatically promoted to real ones;
  1226 
  1227 * slightly changed interfaces for oracles: admit many per theory, named
  1228 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  1229 
  1230 * print_goals: optional output of const types (set show_consts and
  1231 show_types);
  1232 
  1233 * improved output of warnings (###) and errors (***);
  1234 
  1235 * subgoal_tac displays a warning if the new subgoal has type variables;
  1236 
  1237 * removed old README and Makefiles;
  1238 
  1239 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  1240 
  1241 * removed obsolete init_pps and init_database;
  1242 
  1243 * deleted the obsolete tactical STATE, which was declared by
  1244     fun STATE tacfun st = tacfun st st;
  1245 
  1246 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  1247 (which abbreviates $HOME);
  1248 
  1249 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  1250 use isatool fixseq to adapt your ML programs (this works for fully
  1251 qualified references to the Sequence structure only!);
  1252 
  1253 * use_thy no longer requires writable current directory; it always
  1254 reloads .ML *and* .thy file, if either one is out of date;
  1255 
  1256 
  1257 *** Classical Reasoner ***
  1258 
  1259 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  1260 tactics that use classical reasoning to simplify a subgoal without
  1261 splitting it into several subgoals;
  1262 
  1263 * Safe_tac: like safe_tac but uses the default claset;
  1264 
  1265 
  1266 *** Simplifier ***
  1267 
  1268 * added simplification meta rules:
  1269     (asm_)(full_)simplify: simpset -> thm -> thm;
  1270 
  1271 * simplifier.ML no longer part of Pure -- has to be loaded by object
  1272 logics (again);
  1273 
  1274 * added prems argument to simplification procedures;
  1275 
  1276 * HOL, FOL, ZF: added infix function `addsplits':
  1277   instead of `<simpset> setloop (split_tac <thms>)'
  1278   you can simply write `<simpset> addsplits <thms>'
  1279 
  1280 
  1281 *** Syntax ***
  1282 
  1283 * TYPE('a) syntax for type reflection terms;
  1284 
  1285 * no longer handles consts with name "" -- declare as 'syntax' instead;
  1286 
  1287 * pretty printer: changed order of mixfix annotation preference (again!);
  1288 
  1289 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  1290 
  1291 
  1292 *** HOL ***
  1293 
  1294 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1295   with `addloop' of the simplifier to faciliate case splitting in premises.
  1296 
  1297 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  1298 
  1299 * HOL/Auth: new protocol proofs including some for the Internet
  1300   protocol TLS;
  1301 
  1302 * HOL/Map: new theory of `maps' a la VDM;
  1303 
  1304 * HOL/simplifier: simplification procedures nat_cancel_sums for
  1305 cancelling out common nat summands from =, <, <= (in)equalities, or
  1306 differences; simplification procedures nat_cancel_factor for
  1307 cancelling common factor from =, <, <= (in)equalities over natural
  1308 sums; nat_cancel contains both kinds of procedures, it is installed by
  1309 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  1310 
  1311 * HOL/simplifier: terms of the form
  1312   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  1313   are rewritten to
  1314   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  1315   and those of the form
  1316   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  1317   are rewritten to
  1318   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  1319 
  1320 * HOL/datatype
  1321   Each datatype `t' now comes with a theorem `split_t_case' of the form
  1322 
  1323   P(t_case f1 ... fn x) =
  1324      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  1325         ...
  1326        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  1327      )
  1328 
  1329   and a theorem `split_t_case_asm' of the form
  1330 
  1331   P(t_case f1 ... fn x) =
  1332     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  1333         ...
  1334        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  1335      )
  1336   which can be added to a simpset via `addsplits'. The existing theorems
  1337   expand_list_case and expand_option_case have been renamed to
  1338   split_list_case and split_option_case.
  1339 
  1340 * HOL/Arithmetic:
  1341   - `pred n' is automatically converted to `n-1'.
  1342     Users are strongly encouraged not to use `pred' any longer,
  1343     because it will disappear altogether at some point.
  1344   - Users are strongly encouraged to write "0 < n" rather than
  1345     "n ~= 0". Theorems and proof tools have been modified towards this
  1346     `standard'.
  1347 
  1348 * HOL/Lists:
  1349   the function "set_of_list" has been renamed "set" (and its theorems too);
  1350   the function "nth" now takes its arguments in the reverse order and
  1351   has acquired the infix notation "!" as in "xs!n".
  1352 
  1353 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  1354 
  1355 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  1356   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  1357 
  1358 * HOL/record: extensible records with schematic structural subtyping
  1359 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  1360 still lacks various theorems and concrete record syntax;
  1361 
  1362 
  1363 *** HOLCF ***
  1364 
  1365 * removed "axioms" and "generated by" sections;
  1366 
  1367 * replaced "ops" section by extended "consts" section, which is capable of
  1368   handling the continuous function space "->" directly;
  1369 
  1370 * domain package:
  1371   . proves theorems immediately and stores them in the theory,
  1372   . creates hierachical name space,
  1373   . now uses normal mixfix annotations (instead of cinfix...),
  1374   . minor changes to some names and values (for consistency),
  1375   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  1376   . separator between mutual domain defs: changed "," to "and",
  1377   . improved handling of sort constraints;  now they have to
  1378     appear on the left-hand side of the equations only;
  1379 
  1380 * fixed LAM <x,y,zs>.b syntax;
  1381 
  1382 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  1383 adm (%x. P (t x)), where P is chainfinite and t continuous;
  1384 
  1385 
  1386 *** FOL and ZF ***
  1387 
  1388 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1389   with `addloop' of the simplifier to faciliate case splitting in premises.
  1390 
  1391 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  1392 in HOL, they strip ALL and --> from proved theorems;
  1393 
  1394 
  1395 
  1396 New in Isabelle94-8 (May 1997)
  1397 ------------------------------
  1398 
  1399 *** General Changes ***
  1400 
  1401 * new utilities to build / run / maintain Isabelle etc. (in parts
  1402 still somewhat experimental); old Makefiles etc. still functional;
  1403 
  1404 * new 'Isabelle System Manual';
  1405 
  1406 * INSTALL text, together with ./configure and ./build scripts;
  1407 
  1408 * reimplemented type inference for greater efficiency, better error
  1409 messages and clean internal interface;
  1410 
  1411 * prlim command for dealing with lots of subgoals (an easier way of
  1412 setting goals_limit);
  1413 
  1414 
  1415 *** Syntax ***
  1416 
  1417 * supports alternative (named) syntax tables (parser and pretty
  1418 printer); internal interface is provided by add_modesyntax(_i);
  1419 
  1420 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  1421 be used in conjunction with the Isabelle symbol font; uses the
  1422 "symbols" syntax table;
  1423 
  1424 * added token_translation interface (may translate name tokens in
  1425 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  1426 the current print_mode); IMPORTANT: user print translation functions
  1427 are responsible for marking newly introduced bounds
  1428 (Syntax.mark_boundT);
  1429 
  1430 * token translations for modes "xterm" and "xterm_color" that display
  1431 names in bold, underline etc. or colors (which requires a color
  1432 version of xterm);
  1433 
  1434 * infixes may now be declared with names independent of their syntax;
  1435 
  1436 * added typed_print_translation (like print_translation, but may
  1437 access type of constant);
  1438 
  1439 
  1440 *** Classical Reasoner ***
  1441 
  1442 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  1443 some limitations.  Blast_tac...
  1444   + ignores addss, addbefore, addafter; this restriction is intrinsic
  1445   + ignores elimination rules that don't have the correct format
  1446         (the conclusion MUST be a formula variable)
  1447   + ignores types, which can make HOL proofs fail
  1448   + rules must not require higher-order unification, e.g. apply_type in ZF
  1449     [message "Function Var's argument not a bound variable" relates to this]
  1450   + its proof strategy is more general but can actually be slower
  1451 
  1452 * substitution with equality assumptions no longer permutes other
  1453 assumptions;
  1454 
  1455 * minor changes in semantics of addafter (now called addaltern); renamed
  1456 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  1457 (and access functions for it);
  1458 
  1459 * improved combination of classical reasoner and simplifier:
  1460   + functions for handling clasimpsets
  1461   + improvement of addss: now the simplifier is called _after_ the
  1462     safe steps.
  1463   + safe variant of addss called addSss: uses safe simplifications
  1464     _during_ the safe steps. It is more complete as it allows multiple
  1465     instantiations of unknowns (e.g. with slow_tac).
  1466 
  1467 *** Simplifier ***
  1468 
  1469 * added interface for simplification procedures (functions that
  1470 produce *proven* rewrite rules on the fly, depending on current
  1471 redex);
  1472 
  1473 * ordering on terms as parameter (used for ordered rewriting);
  1474 
  1475 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  1476 
  1477 * the solver is now split into a safe and an unsafe part.
  1478 This should be invisible for the normal user, except that the
  1479 functions setsolver and addsolver have been renamed to setSolver and
  1480 addSolver; added safe_asm_full_simp_tac;
  1481 
  1482 
  1483 *** HOL ***
  1484 
  1485 * a generic induction tactic `induct_tac' which works for all datatypes and
  1486 also for type `nat';
  1487 
  1488 * a generic case distinction tactic `exhaust_tac' which works for all
  1489 datatypes and also for type `nat';
  1490 
  1491 * each datatype comes with a function `size';
  1492 
  1493 * patterns in case expressions allow tuple patterns as arguments to
  1494 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  1495 
  1496 * primrec now also works with type nat;
  1497 
  1498 * recdef: a new declaration form, allows general recursive functions to be
  1499 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  1500 
  1501 * the constant for negation has been renamed from "not" to "Not" to
  1502 harmonize with FOL, ZF, LK, etc.;
  1503 
  1504 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  1505 infinite lists;
  1506 
  1507 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  1508 
  1509 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  1510 problems in commutative rings, using axiomatic type classes for + and *;
  1511 
  1512 * more examples in HOL/MiniML and HOL/Auth;
  1513 
  1514 * more default rewrite rules for quantifiers, union/intersection;
  1515 
  1516 * a new constant `arbitrary == @x.False';
  1517 
  1518 * HOLCF/IOA replaces old HOL/IOA;
  1519 
  1520 * HOLCF changes: derived all rules and arities
  1521   + axiomatic type classes instead of classes
  1522   + typedef instead of faking type definitions
  1523   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  1524   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  1525   + eliminated the types void, one, tr
  1526   + use unit lift and bool lift (with translations) instead of one and tr
  1527   + eliminated blift from Lift3.thy (use Def instead of blift)
  1528   all eliminated rules are derived as theorems --> no visible changes ;
  1529 
  1530 
  1531 *** ZF ***
  1532 
  1533 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  1534 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  1535 as ZF_cs addSIs [equalityI];
  1536 
  1537 
  1538 
  1539 New in Isabelle94-7 (November 96)
  1540 ---------------------------------
  1541 
  1542 * allowing negative levels (as offsets) in prlev and choplev;
  1543 
  1544 * super-linear speedup for large simplifications;
  1545 
  1546 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  1547 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  1548 FAIL); can suppress it using the command Delsimps (ex_simps @
  1549 all_simps); De Morgan laws are also now included, by default;
  1550 
  1551 * improved printing of ==>  :  ~:
  1552 
  1553 * new object-logic "Sequents" adds linear logic, while replacing LK
  1554 and Modal (thanks to Sara Kalvala);
  1555 
  1556 * HOL/Auth: correctness proofs for authentication protocols;
  1557 
  1558 * HOL: new auto_tac combines rewriting and classical reasoning (many
  1559 examples on HOL/Auth);
  1560 
  1561 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  1562 the rewriter and classical reasoner simultaneously;
  1563 
  1564 * function uresult no longer returns theorems in "standard" format;
  1565 regain previous version by: val uresult = standard o uresult;
  1566 
  1567 
  1568 
  1569 New in Isabelle94-6
  1570 -------------------
  1571 
  1572 * oracles -- these establish an interface between Isabelle and trusted
  1573 external reasoners, which may deliver results as theorems;
  1574 
  1575 * proof objects (in particular record all uses of oracles);
  1576 
  1577 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  1578 
  1579 * "constdefs" section in theory files;
  1580 
  1581 * "primrec" section (HOL) no longer requires names;
  1582 
  1583 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  1584 
  1585 
  1586 
  1587 New in Isabelle94-5
  1588 -------------------
  1589 
  1590 * reduced space requirements;
  1591 
  1592 * automatic HTML generation from theories;
  1593 
  1594 * theory files no longer require "..." (quotes) around most types;
  1595 
  1596 * new examples, including two proofs of the Church-Rosser theorem;
  1597 
  1598 * non-curried (1994) version of HOL is no longer distributed;
  1599 
  1600 
  1601 
  1602 New in Isabelle94-4
  1603 -------------------
  1604 
  1605 * greatly reduced space requirements;
  1606 
  1607 * theory files (.thy) no longer require \...\ escapes at line breaks;
  1608 
  1609 * searchable theorem database (see the section "Retrieving theorems" on
  1610 page 8 of the Reference Manual);
  1611 
  1612 * new examples, including Grabczewski's monumental case study of the
  1613 Axiom of Choice;
  1614 
  1615 * The previous version of HOL renamed to Old_HOL;
  1616 
  1617 * The new version of HOL (previously called CHOL) uses a curried syntax
  1618 for functions.  Application looks like f a b instead of f(a,b);
  1619 
  1620 * Mutually recursive inductive definitions finally work in HOL;
  1621 
  1622 * In ZF, pattern-matching on tuples is now available in all abstractions and
  1623 translates to the operator "split";
  1624 
  1625 
  1626 
  1627 New in Isabelle94-3
  1628 -------------------
  1629 
  1630 * new infix operator, addss, allowing the classical reasoner to
  1631 perform simplification at each step of its search.  Example:
  1632         fast_tac (cs addss ss)
  1633 
  1634 * a new logic, CHOL, the same as HOL, but with a curried syntax
  1635 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  1636 look like (a,b) instead of <a,b>;
  1637 
  1638 * PLEASE NOTE: CHOL will eventually replace HOL!
  1639 
  1640 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  1641 It translates to the operator "split".  A new theory of integers is available;
  1642 
  1643 * In ZF, integer numerals now denote two's-complement binary integers.
  1644 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  1645 
  1646 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  1647 of the Axiom of Choice;
  1648 
  1649 
  1650 
  1651 New in Isabelle94-2
  1652 -------------------
  1653 
  1654 * Significantly faster resolution;
  1655 
  1656 * the different sections in a .thy file can now be mixed and repeated
  1657 freely;
  1658 
  1659 * Database of theorems for FOL, HOL and ZF.  New
  1660 commands including qed, qed_goal and bind_thm store theorems in the database.
  1661 
  1662 * Simple database queries: return a named theorem (get_thm) or all theorems of
  1663 a given theory (thms_of), or find out what theory a theorem was proved in
  1664 (theory_of_thm);
  1665 
  1666 * Bugs fixed in the inductive definition and datatype packages;
  1667 
  1668 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  1669 and HOL_dup_cs obsolete;
  1670 
  1671 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  1672 have been removed;
  1673 
  1674 * Simpler definition of function space in ZF;
  1675 
  1676 * new results about cardinal and ordinal arithmetic in ZF;
  1677 
  1678 * 'subtype' facility in HOL for introducing new types as subsets of existing
  1679 types;
  1680 
  1681 
  1682 $Id$