NEWS
author wenzelm
Wed Sep 21 14:46:10 2005 +0200 (2005-09-21 ago)
changeset 17562 623c9e8668aa
parent 17548 4949ab06913c
child 17564 0350ac95c4b6
permissions -rw-r--r--
tuned;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in Isabelle2005 (September 2005)
     5 ------------------------------------
     6 
     7 *** General ***
     8 
     9 * Theory headers: the new header syntax for Isar theories is
    10 
    11   theory <name>
    12   imports <theory1> ... <theoryN>
    13   uses <file1> ... <fileM>
    14   begin
    15 
    16 where the 'uses' part is optional.  The previous syntax
    17 
    18   theory <name> = <theory1> + ... + <theoryN>:
    19 
    20 will disappear in the next release.  Use isatool fixheaders to convert
    21 existing theory files.  Note that there is no change in ancient
    22 non-Isar theories now, but these will disappear soon.
    23 
    24 * Theory loader: parent theories can now also be referred to via
    25 relative and absolute paths.
    26 
    27 * Command 'find_theorems' searches for a list of criteria instead of a
    28 list of constants. Known criteria are: intro, elim, dest, name:string,
    29 simp:term, and any term. Criteria can be preceded by '-' to select
    30 theorems that do not match. Intro, elim, dest select theorems that
    31 match the current goal, name:s selects theorems whose fully qualified
    32 name contain s, and simp:term selects all simplification rules whose
    33 lhs match term.  Any other term is interpreted as pattern and selects
    34 all theorems matching the pattern. Available in ProofGeneral under
    35 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
    36 
    37   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
    38 
    39 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
    40 matching the current goal as introduction rule and not having "HOL."
    41 in their name (i.e. not being defined in theory HOL).
    42 
    43 * Command 'thms_containing' has been discontinued in favour of
    44 'find_theorems'; INCOMPATIBILITY.
    45 
    46 * Communication with Proof General is now 8bit clean, which means that
    47 Unicode text in UTF-8 encoding may be used within theory texts (both
    48 formal and informal parts).  Cf. option -U of the Isabelle Proof
    49 General interface.  Here are some simple examples (cf. src/HOL/ex):
    50 
    51   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
    52   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
    53 
    54 * Improved efficiency of the Simplifier and, to a lesser degree, the
    55 Classical Reasoner.  Typical big applications run around 2 times
    56 faster.
    57 
    58 * ProofGeneral interface: the default settings no longer prefer xemacs
    59 over GNU emacs.  Users typically need to experiment with various
    60 variations on PROOFGENERAL_OPTIONS="... -p emacs" to find the most
    61 stable Emacs version on their platform.
    62 
    63 
    64 *** Document preparation ***
    65 
    66 * Commands 'display_drafts' and 'print_drafts' perform simple output
    67 of raw sources.  Only those symbols that do not require additional
    68 LaTeX packages (depending on comments in isabellesym.sty) are
    69 displayed properly, everything else is left verbatim.  isatool display
    70 and isatool print are used as front ends (these are subject to the
    71 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
    72 
    73 * Command tags control specific markup of certain regions of text,
    74 notably folding and hiding.  Predefined tags include "theory" (for
    75 theory begin and end), "proof" for proof commands, and "ML" for
    76 commands involving ML code; the additional tags "visible" and
    77 "invisible" are unused by default.  Users may give explicit tag
    78 specifications in the text, e.g. ''by %invisible (auto)''.  The
    79 interpretation of tags is determined by the LaTeX job during document
    80 preparation: see option -V of isatool usedir, or options -n and -t of
    81 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
    82 \isadroptag.
    83 
    84 Several document versions may be produced at the same time via isatool
    85 usedir (the generated index.html will link all of them).  Typical
    86 specifications include ''-V document=theory,proof,ML'' to present
    87 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
    88 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
    89 these parts without any formal replacement text.  The Isabelle site
    90 default settings produce ''document'' and ''outline'' versions as
    91 specified above.
    92 
    93 * Several new antiquotations:
    94 
    95   @{term_type term} prints a term with its type annotated;
    96 
    97   @{typeof term} prints the type of a term;
    98 
    99   @{const const} is the same as @{term const}, but checks that the
   100   argument is a known logical constant;
   101 
   102   @{term_style style term} and @{thm_style style thm} print a term or
   103   theorem applying a "style" to it
   104 
   105   @{ML text}
   106 
   107 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
   108 definitions, equations, inequations etc., 'concl' printing only the
   109 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
   110 to print the specified premise.  TermStyle.add_style provides an ML
   111 interface for introducing further styles.  See also the "LaTeX Sugar"
   112 document practical applications.  The ML antiquotation prints
   113 type-checked ML expressions verbatim.
   114 
   115 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
   116 and 'text' support optional locale specification '(in loc)', which
   117 specifies the default context for interpreting antiquotations.  For
   118 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
   119 
   120 * Option 'locale=NAME' of antiquotations specifies an alternative
   121 context interpreting the subsequent argument.  For example: @{thm
   122 [locale=lattice] inf_assoc}.
   123 
   124 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
   125 a proof context.
   126 
   127 * Proper output of antiquotations for theory commands involving a
   128 proof context (such as 'locale' or 'theorem (in loc) ...').
   129 
   130 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
   131 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
   132 
   133 * isatool usedir: new option -C (default true) controls whether option
   134 -D should include a copy of the original document directory; -C false
   135 prevents unwanted effects such as copying of administrative CVS data.
   136 
   137 
   138 *** Pure ***
   139 
   140 * Considerably improved version of 'constdefs' command.  Now performs
   141 automatic type-inference of declared constants; additional support for
   142 local structure declarations (cf. locales and HOL records), see also
   143 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
   144 sequential dependencies of definitions within a single 'constdefs'
   145 section; moreover, the declared name needs to be an identifier.  If
   146 all fails, consider to fall back on 'consts' and 'defs' separately.
   147 
   148 * Improved indexed syntax and implicit structures.  First of all,
   149 indexed syntax provides a notational device for subscripted
   150 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
   151 expressions.  Secondly, in a local context with structure
   152 declarations, number indexes \<^sub>n or the empty index (default
   153 number 1) refer to a certain fixed variable implicitly; option
   154 show_structs controls printing of implicit structures.  Typical
   155 applications of these concepts involve record types and locales.
   156 
   157 * New command 'no_syntax' removes grammar declarations (and
   158 translations) resulting from the given syntax specification, which is
   159 interpreted in the same manner as for the 'syntax' command.
   160 
   161 * 'Advanced' translation functions (parse_translation etc.) may depend
   162 on the signature of the theory context being presently used for
   163 parsing/printing, see also isar-ref manual.
   164 
   165 * Improved 'oracle' command provides a type-safe interface to turn an
   166 ML expression of type theory -> T -> term into a primitive rule of
   167 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
   168 is already included here); see also FOL/ex/IffExample.thy;
   169 INCOMPATIBILITY.
   170 
   171 * axclass: name space prefix for class "c" is now "c_class" (was "c"
   172 before); "cI" is no longer bound, use "c.intro" instead.
   173 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
   174 axclasses vs. locales.
   175 
   176 * Improved internal renaming of symbolic identifiers -- attach primes
   177 instead of base 26 numbers.
   178 
   179 * New flag show_question_marks controls printing of leading question
   180 marks in schematic variable names.
   181 
   182 * In schematic variable names, *any* symbol following \<^isub> or
   183 \<^isup> is now treated as part of the base name.  For example, the
   184 following works without printing of awkward ".0" indexes:
   185 
   186   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
   187     by simp
   188 
   189 * Inner syntax includes (*(*nested*) comments*).
   190 
   191 * Pretty printer now supports unbreakable blocks, specified in mixfix
   192 annotations as "(00...)".
   193 
   194 * Clear separation of logical types and nonterminals, where the latter
   195 may only occur in 'syntax' specifications or type abbreviations.
   196 Before that distinction was only partially implemented via type class
   197 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
   198 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
   199 exotic syntax specifications may require further adaption
   200 (e.g. Cube/Base.thy).
   201 
   202 * Removed obsolete type class "logic", use the top sort {} instead.
   203 Note that non-logical types should be declared as 'nonterminals'
   204 rather than 'types'.  INCOMPATIBILITY for new object-logic
   205 specifications.
   206 
   207 * 'defs': more well-formedness checks of overloaded definitions.
   208 
   209 * Attributes 'induct' and 'cases': type or set names may now be
   210 locally fixed variables as well.
   211 
   212 * Simplifier: can now control the depth to which conditional rewriting
   213 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
   214 Limit.
   215 
   216 * Simplifier: simplification procedures may now take the current
   217 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
   218 interface), which is very useful for calling the Simplifier
   219 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
   220 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
   221 low-level mk_simproc no longer applies Logic.varify internally, to
   222 allow for use in a context of fixed variables.
   223 
   224 * thin_tac now works even if the assumption being deleted contains !!
   225 or ==>.  More generally, erule now works even if the major premise of
   226 the elimination rule contains !! or ==>.
   227 
   228 * Reorganized bootstrapping of the Pure theories; CPure is now derived
   229 from Pure, which contains all common declarations already.  Both
   230 theories are defined via plain Isabelle/Isar .thy files.
   231 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
   232 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
   233 use isatool fixcpure to adapt your theory and ML sources.
   234 
   235 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
   236 selections of theorems in named facts via index ranges.
   237 
   238 * 'print_theorems': in theory mode, really print the difference
   239 wrt. the last state (works for interactive theory development only),
   240 in proof mode print all local facts (cf. 'print_facts');
   241 
   242 * 'hide': option '(open)' hides only base names.
   243 
   244 * More efficient treatment of intermediate checkpoints in interactive
   245 theory development.
   246 
   247 
   248 *** Locales ***
   249 
   250 * New commands for the interpretation of locale expressions in
   251 theories (1), locales (2) and proof contexts (3).  These generate
   252 proof obligations from the expression specification.  After the
   253 obligations have been discharged, theorems of the expression are added
   254 to the theory, target locale or proof context.  The synopsis of the
   255 commands is a follows:
   256 
   257   (1) interpretation expr inst
   258   (2) interpretation target < expr
   259   (3) interpret expr inst
   260 
   261 Interpretation in theories and proof contexts require a parameter
   262 instantiation of terms from the current context.  This is applied to
   263 specifications and theorems of the interpreted expression.
   264 Interpretation in locales only permits parameter renaming through the
   265 locale expression.  Interpretation is smart in that interpretations
   266 that are active already do not occur in proof obligations, neither are
   267 instantiated theorems stored in duplicate.  Use 'print_interps' to
   268 inspect active interpretations of a particular locale.  For details,
   269 see the Isar Reference manual.  Examples can be found in
   270 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
   271 
   272 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
   273 'interpret' instead.
   274 
   275 * New context element 'constrains' for adding type constraints to
   276 parameters.
   277 
   278 * Context expressions: renaming of parameters with syntax
   279 redeclaration.
   280 
   281 * Locale declaration: 'includes' disallowed.
   282 
   283 * Proper static binding of attribute syntax -- i.e. types / terms /
   284 facts mentioned as arguments are always those of the locale definition
   285 context, independently of the context of later invocations.  Moreover,
   286 locale operations (renaming and type / term instantiation) are applied
   287 to attribute arguments as expected.
   288 
   289 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
   290 actual attributes; rare situations may require Attrib.attribute to
   291 embed those attributes into Attrib.src that lack concrete syntax.
   292 Attribute implementations need to cooperate properly with the static
   293 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
   294 Attrib.XXX_thm etc. already do the right thing without further
   295 intervention.  Only unusual applications -- such as "where" or "of"
   296 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
   297 on the context and the facts involved -- may have to assign parsed
   298 values to argument tokens explicitly.
   299 
   300 * Changed parameter management in theorem generation for long goal
   301 statements with 'includes'.  INCOMPATIBILITY: produces a different
   302 theorem statement in rare situations.
   303 
   304 * Locale inspection command 'print_locale' omits notes elements.  Use
   305 'print_locale!' to have them included in the output.
   306 
   307 
   308 *** Provers ***
   309 
   310 * Provers/hypsubst.ML: improved version of the subst method, for
   311 single-step rewriting: it now works in bound variable contexts. New is
   312 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
   313 rewrite a different subterm than the original subst method, which is
   314 still available as 'simplesubst'.
   315 
   316 * Provers/quasi.ML: new transitivity reasoners for transitivity only
   317 and quasi orders.
   318 
   319 * Provers/trancl.ML: new transitivity reasoner for transitive and
   320 reflexive-transitive closure of relations.
   321 
   322 * Provers/blast.ML: new reference depth_limit to make blast's depth
   323 limit (previously hard-coded with a value of 20) user-definable.
   324 
   325 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
   326 is peformed already.  Object-logics merely need to finish their
   327 initial simpset configuration as before.  INCOMPATIBILITY.
   328 
   329 
   330 *** HOL ***
   331 
   332 * Symbolic syntax of Hilbert Choice Operator is now as follows:
   333 
   334   syntax (epsilon)
   335     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
   336 
   337 The symbol \<some> is displayed as the alternative epsilon of LaTeX
   338 and x-symbol; use option '-m epsilon' to get it actually printed.
   339 Moreover, the mathematically important symbolic identifier \<epsilon>
   340 becomes available as variable, constant etc.  INCOMPATIBILITY,
   341 
   342 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
   343 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
   344 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
   345 support corresponding Isar calculations.
   346 
   347 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
   348 instead of ":".
   349 
   350 * theory SetInterval: changed the syntax for open intervals:
   351 
   352   Old       New
   353   {..n(}    {..<n}
   354   {)n..}    {n<..}
   355   {m..n(}   {m..<n}
   356   {)m..n}   {m<..n}
   357   {)m..n(}  {m<..<n}
   358 
   359 The old syntax is still supported but will disappear in the next
   360 release.  For conversion use the following Emacs search and replace
   361 patterns (these are not perfect but work quite well):
   362 
   363   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
   364   \.\.\([^(}]*\)(}  ->  \.\.<\1}
   365 
   366 * Theory Commutative_Ring (in Library): method comm_ring for proving
   367 equalities in commutative rings; method 'algebra' provides a generic
   368 interface.
   369 
   370 * Theory Finite_Set: changed the syntax for 'setsum', summation over
   371 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
   372 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
   373 be a tuple pattern.
   374 
   375 Some new syntax forms are available:
   376 
   377   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
   378   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
   379   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
   380   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
   381 
   382 The latter form "\<Sum>x < k. e" used to be based on a separate
   383 function "Summation", which has been discontinued.
   384 
   385 * theory Finite_Set: in structured induction proofs, the insert case
   386 is now 'case (insert x F)' instead of the old counterintuitive 'case
   387 (insert F x)'.
   388 
   389 * The 'refute' command has been extended to support a much larger
   390 fragment of HOL, including axiomatic type classes, constdefs and
   391 typedefs, inductive datatypes and recursion.
   392 
   393 * Datatype induction via method 'induct' now preserves the name of the
   394 induction variable. For example, when proving P(xs::'a list) by
   395 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
   396 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
   397 in unstructured proof scripts.
   398 
   399 * Reworked implementation of records.  Improved scalability for
   400 records with many fields, avoiding performance problems for type
   401 inference. Records are no longer composed of nested field types, but
   402 of nested extension types. Therefore the record type only grows linear
   403 in the number of extensions and not in the number of fields.  The
   404 top-level (users) view on records is preserved.  Potential
   405 INCOMPATIBILITY only in strange cases, where the theory depends on the
   406 old record representation. The type generated for a record is called
   407 <record_name>_ext_type.
   408 
   409 Flag record_quick_and_dirty_sensitive can be enabled to skip the
   410 proofs triggered by a record definition or a simproc (if
   411 quick_and_dirty is enabled).  Definitions of large records can take
   412 quite long.
   413 
   414 New simproc record_upd_simproc for simplification of multiple record
   415 updates enabled by default.  Moreover, trivial updates are also
   416 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
   417 occasionally, since simplification is more powerful by default.
   418 
   419 * typedef: proper support for polymorphic sets, which contain extra
   420 type-variables in the term.
   421 
   422 * Simplifier: automatically reasons about transitivity chains
   423 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
   424 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
   425 old proofs break occasionally as simplification may now solve more
   426 goals than previously.
   427 
   428 * Simplifier: converts x <= y into x = y if assumption y <= x is
   429 present.  Works for all partial orders (class "order"), in particular
   430 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
   431 just like y <= x.
   432 
   433 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
   434 bound variable or a constant then the let is unfolded.  Otherwise
   435 first a is simplified to b, and then f b is simplified to g. If
   436 possible we abstract b from g arriving at "let x = b in h x",
   437 otherwise we unfold the let and arrive at g.  The simproc can be
   438 enabled/disabled by the reference use_let_simproc.  Potential
   439 INCOMPATIBILITY since simplification is more powerful by default.
   440 
   441 * Classical reasoning: the meson method now accepts theorems as arguments.
   442 
   443 * Theory OrderedGroup and Ring_and_Field: various additions and
   444 improvements to faciliate calculations involving equalities and
   445 inequalities.
   446 
   447 The following theorems have been eliminated or modified
   448 (INCOMPATIBILITY):
   449 
   450   abs_eq             now named abs_of_nonneg
   451   abs_of_ge_0        now named abs_of_nonneg
   452   abs_minus_eq       now named abs_of_nonpos
   453   imp_abs_id         now named abs_of_nonneg
   454   imp_abs_neg_id     now named abs_of_nonpos
   455   mult_pos           now named mult_pos_pos
   456   mult_pos_le        now named mult_nonneg_nonneg
   457   mult_pos_neg_le    now named mult_nonneg_nonpos
   458   mult_pos_neg2_le   now named mult_nonneg_nonpos2
   459   mult_neg           now named mult_neg_neg
   460   mult_neg_le        now named mult_nonpos_nonpos
   461 
   462 * Theory Parity: added rules for simplifying exponents.
   463 
   464 * Theory List:
   465 
   466 The following theorems have been eliminated or modified
   467 (INCOMPATIBILITY):
   468 
   469   list_all_Nil       now named list_all.simps(1)
   470   list_all_Cons      now named list_all.simps(2)
   471   list_all_conv      now named list_all_iff
   472   set_mem_eq         now named mem_iff
   473 
   474 * Theories SetsAndFunctions and BigO (see HOL/Library) support
   475 asymptotic "big O" calculations.  See the notes in BigO.thy.
   476 
   477 
   478 *** HOL-Complex ***
   479 
   480 * Theory RealDef: better support for embedding natural numbers and
   481 integers in the reals.
   482 
   483 The following theorems have been eliminated or modified
   484 (INCOMPATIBILITY):
   485 
   486   exp_ge_add_one_self  now requires no hypotheses
   487   real_of_int_add      reversed direction of equality (use [symmetric])
   488   real_of_int_minus    reversed direction of equality (use [symmetric])
   489   real_of_int_diff     reversed direction of equality (use [symmetric])
   490   real_of_int_mult     reversed direction of equality (use [symmetric])
   491 
   492 * Theory RComplete: expanded support for floor and ceiling functions.
   493 
   494 * Theory Ln is new, with properties of the natural logarithm
   495 
   496 * Hyperreal: There is a new type constructor "star" for making
   497 nonstandard types.  The old type names are now type synonyms:
   498 
   499   hypreal = real star
   500   hypnat = nat star
   501   hcomplex = complex star
   502 
   503 * Hyperreal: Many groups of similarly-defined constants have been
   504 replaced by polymorphic versions (INCOMPATIBILITY):
   505 
   506   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
   507 
   508   starset      <-- starsetNat, starsetC
   509   *s*          <-- *sNat*, *sc*
   510   starset_n    <-- starsetNat_n, starsetC_n
   511   *sn*         <-- *sNatn*, *scn*
   512   InternalSets <-- InternalNatSets, InternalCSets
   513 
   514   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
   515   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
   516   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
   517   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
   518   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
   519 
   520 * Hyperreal: Many type-specific theorems have been removed in favor of
   521 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
   522 
   523   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
   524   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
   525   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
   526   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
   527   right_minus <-- hypreal_add_minus
   528   left_minus <-- {hypreal,hcomplex}_add_minus_left
   529   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
   530   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
   531   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
   532   mult_1_right <-- hcomplex_mult_one_right
   533   mult_zero_left <-- hcomplex_mult_zero_left
   534   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
   535   right_distrib <-- hypnat_add_mult_distrib2
   536   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
   537   right_inverse <-- hypreal_mult_inverse
   538   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
   539   order_refl <-- {hypreal,hypnat}_le_refl
   540   order_trans <-- {hypreal,hypnat}_le_trans
   541   order_antisym <-- {hypreal,hypnat}_le_anti_sym
   542   order_less_le <-- {hypreal,hypnat}_less_le
   543   linorder_linear <-- {hypreal,hypnat}_le_linear
   544   add_left_mono <-- {hypreal,hypnat}_add_left_mono
   545   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
   546   add_nonneg_nonneg <-- hypreal_le_add_order
   547 
   548 * Hyperreal: Separate theorems having to do with type-specific
   549 versions of constants have been merged into theorems that apply to the
   550 new polymorphic constants (INCOMPATIBILITY):
   551 
   552   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
   553   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
   554   STAR_Un <-- {STAR,NatStar,STARC}_Un
   555   STAR_Int <-- {STAR,NatStar,STARC}_Int
   556   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
   557   STAR_subset <-- {STAR,NatStar,STARC}_subset
   558   STAR_mem <-- {STAR,NatStar,STARC}_mem
   559   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
   560   STAR_diff <-- {STAR,STARC}_diff
   561   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
   562     STARC_hcomplex_of_complex}_image_subset
   563   starset_n_Un <-- starset{Nat,C}_n_Un
   564   starset_n_Int <-- starset{Nat,C}_n_Int
   565   starset_n_Compl <-- starset{Nat,C}_n_Compl
   566   starset_n_diff <-- starset{Nat,C}_n_diff
   567   InternalSets_Un <-- Internal{Nat,C}Sets_Un
   568   InternalSets_Int <-- Internal{Nat,C}Sets_Int
   569   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
   570   InternalSets_diff <-- Internal{Nat,C}Sets_diff
   571   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
   572   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
   573   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
   574   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
   575   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
   576   starfun <-- starfun{Nat,Nat2,C,RC,CR}
   577   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
   578   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
   579   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
   580   starfun_diff <-- starfun{C,RC,CR}_diff
   581   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
   582   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
   583   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
   584   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
   585   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
   586   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
   587   starfun_Id <-- starfunC_Id
   588   starfun_approx <-- starfun{Nat,CR}_approx
   589   starfun_capprox <-- starfun{C,RC}_capprox
   590   starfun_abs <-- starfunNat_rabs
   591   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
   592   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
   593   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
   594   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
   595   starfun_add_capprox <-- starfun{C,RC}_add_capprox
   596   starfun_add_approx <-- starfunCR_add_approx
   597   starfun_inverse_inverse <-- starfunC_inverse_inverse
   598   starfun_divide <-- starfun{C,CR,RC}_divide
   599   starfun_n <-- starfun{Nat,C}_n
   600   starfun_n_mult <-- starfun{Nat,C}_n_mult
   601   starfun_n_add <-- starfun{Nat,C}_n_add
   602   starfun_n_add_minus <-- starfunNat_n_add_minus
   603   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
   604   starfun_n_minus <-- starfun{Nat,C}_n_minus
   605   starfun_n_eq <-- starfun{Nat,C}_n_eq
   606 
   607   star_n_add <-- {hypreal,hypnat,hcomplex}_add
   608   star_n_minus <-- {hypreal,hcomplex}_minus
   609   star_n_diff <-- {hypreal,hcomplex}_diff
   610   star_n_mult <-- {hypreal,hcomplex}_mult
   611   star_n_inverse <-- {hypreal,hcomplex}_inverse
   612   star_n_le <-- {hypreal,hypnat}_le
   613   star_n_less <-- {hypreal,hypnat}_less
   614   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
   615   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
   616   star_n_abs <-- hypreal_hrabs
   617   star_n_divide <-- hcomplex_divide
   618 
   619   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
   620   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
   621   star_of_diff <-- hypreal_of_real_diff
   622   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
   623   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
   624   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
   625   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
   626   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
   627   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
   628   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
   629   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
   630   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
   631   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
   632   star_of_number_of <-- {hypreal,hcomplex}_number_of
   633   star_of_number_less <-- number_of_less_hypreal_of_real_iff
   634   star_of_number_le <-- number_of_le_hypreal_of_real_iff
   635   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
   636   star_of_less_number <-- hypreal_of_real_less_number_of_iff
   637   star_of_le_number <-- hypreal_of_real_le_number_of_iff
   638   star_of_power <-- hypreal_of_real_power
   639   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
   640 
   641 * Hyperreal: new method "transfer" that implements the transfer
   642 principle of nonstandard analysis. With a subgoal that mentions
   643 nonstandard types like "'a star", the command "apply transfer"
   644 replaces it with an equivalent one that mentions only standard types.
   645 To be successful, all free variables must have standard types; non-
   646 standard variables must have explicit universal quantifiers.
   647 
   648 
   649 *** HOLCF ***
   650 
   651 * Discontinued special version of 'constdefs' (which used to support
   652 continuous functions) in favor of the general Pure one with full
   653 type-inference.
   654 
   655 * New simplification procedure for solving continuity conditions; it
   656 is much faster on terms with many nested lambda abstractions (cubic
   657 instead of exponential time).
   658 
   659 * New syntax for domain package: selector names are now optional.
   660 Parentheses should be omitted unless argument is lazy, for example:
   661 
   662   domain 'a stream = cons "'a" (lazy "'a stream")
   663 
   664 * New command 'fixrec' for defining recursive functions with pattern
   665 matching; defining multiple functions with mutual recursion is also
   666 supported.  Patterns may include the constants cpair, spair, up, sinl,
   667 sinr, or any data constructor defined by the domain package. The given
   668 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
   669 syntax and examples.
   670 
   671 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
   672 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
   673 but the proof obligation additionally includes an admissibility
   674 requirement. The packages generate instances of class cpo or pcpo,
   675 with continuity and strictness theorems for Rep and Abs.
   676 
   677 
   678 *** ZF ***
   679 
   680 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
   681 including the First Isomorphism Theorem (on quotienting by the kernel
   682 of a homomorphism).
   683 
   684 * ZF/Simplifier: install second copy of type solver that actually
   685 makes use of TC rules declared to Isar proof contexts (or locales);
   686 the old version is still required for ML proof scripts.
   687 
   688 
   689 *** Cube ***
   690 
   691 * Converted to Isar theory format; use locales instead of axiomatic
   692 theories.
   693 
   694 
   695 *** ML ***
   696 
   697 * Pure/library.ML no longer defines its own option datatype, but uses
   698 that of the SML basis, which has constructors NONE and SOME instead of
   699 None and Some, as well as exception Option.Option instead of OPTION.
   700 The functions the, if_none, is_some, is_none have been adapted
   701 accordingly, while Option.map replaces apsome.
   702 
   703 * Pure/library.ML: the exception LIST has been given up in favour of
   704 the standard exceptions Empty and Subscript, as well as
   705 Library.UnequalLengths.  Function like Library.hd and Library.tl are
   706 superceded by the standard hd and tl functions etc.
   707 
   708 A number of basic list functions are no longer exported to the ML
   709 toplevel, as they are variants of predefined functions.  The following
   710 suggests how one can translate existing code:
   711 
   712     rev_append xs ys = List.revAppend (xs, ys)
   713     nth_elem (i, xs) = List.nth (xs, i)
   714     last_elem xs = List.last xs
   715     flat xss = List.concat xss
   716     seq fs = List.app fs
   717     partition P xs = List.partition P xs
   718     mapfilter f xs = List.mapPartial f xs
   719 
   720 * Pure/library.ML: several combinators for linear functional
   721 transformations, notably reverse application and composition:
   722 
   723   x |> f                f #> g
   724   (x, y) |-> f          f #-> g
   725 
   726 * Pure/library.ML: introduced/changed precedence of infix operators:
   727 
   728   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
   729   infix 2 ?;
   730   infix 3 o oo ooo oooo;
   731   infix 4 ~~ upto downto;
   732 
   733 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
   734 infix operators.
   735 
   736 * Pure/library.ML: natural list combinators fold, fold_rev, and
   737 fold_map support linear functional transformations and nesting.  For
   738 example:
   739 
   740   fold f [x1, ..., xN] y =
   741     y |> f x1 |> ... |> f xN
   742 
   743   (fold o fold) f [xs1, ..., xsN] y =
   744     y |> fold f xs1 |> ... |> fold f xsN
   745 
   746   fold f [x1, ..., xN] =
   747     f x1 #> ... #> f xN
   748 
   749   (fold o fold) f [xs1, ..., xsN] =
   750     fold f xs1 #> ... #> fold f xsN
   751 
   752 * Pure/library.ML: the following selectors on type 'a option are
   753 available:
   754 
   755   the:               'a option -> 'a  (*partial*)
   756   these:             'a option -> 'a  where 'a = 'b list
   757   the_default: 'a -> 'a option -> 'a
   758   the_list:          'a option -> 'a list
   759 
   760 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
   761 basic operations for association lists, following natural argument
   762 order; ; moreover the explicit equality predicate passed here avoids
   763 potentially expensive polymorphic runtime equality checks.
   764 The old functions may be expressed as follows:
   765 
   766   assoc = uncurry (AList.lookup (op =))
   767   assocs = these oo AList.lookup (op =)
   768   overwrite = uncurry (AList.update (op =)) o swap
   769 
   770 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
   771 provides a reasonably efficient light-weight implementation of sets as
   772 lists.
   773 
   774 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
   775 few new operations; existing lookup and update are now curried to
   776 follow natural argument order (for use with fold etc.);
   777 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
   778 
   779 * Pure/General: output via the Isabelle channels of
   780 writeln/warning/error etc. is now passed through Output.output, with a
   781 hook for arbitrary transformations depending on the print_mode
   782 (cf. Output.add_mode -- the first active mode that provides a output
   783 function wins).  Already formatted output may be embedded into further
   784 text via Output.raw; the result of Pretty.string_of/str_of and derived
   785 functions (string_of_term/cterm/thm etc.) is already marked raw to
   786 accommodate easy composition of diagnostic messages etc.  Programmers
   787 rarely need to care about Output.output or Output.raw at all, with
   788 some notable exceptions: Output.output is required when bypassing the
   789 standard channels (writeln etc.), or in token translations to produce
   790 properly formatted results; Output.raw is required when capturing
   791 already output material that will eventually be presented to the user
   792 a second time.  For the default print mode, both Output.output and
   793 Output.raw have no effect.
   794 
   795 * Pure/General: Output.time_accumulator NAME creates an operator ('a
   796 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
   797 cumulative results are displayed at the end of a batch session.
   798 
   799 * Pure/General: File.sysify_path and File.quote_sysify path have been
   800 replaced by File.platform_path and File.shell_path (with appropriate
   801 hooks).  This provides a clean interface for unusual systems where the
   802 internal and external process view of file names are different.
   803 
   804 * Pure: more efficient orders for basic syntactic entities: added
   805 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
   806 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
   807 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
   808 orders now -- potential INCOMPATIBILITY for code that depends on a
   809 particular order for Symtab.keys, Symtab.dest, etc. (consider using
   810 Library.sort_strings on result).
   811 
   812 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
   813 fold_types traverse types/terms from left to right, observing natural
   814 argument order.  Supercedes previous foldl_XXX versions, add_frees,
   815 add_vars etc. have been adapted as well: INCOMPATIBILITY.
   816 
   817 * Pure: name spaces have been refined, with significant changes of the
   818 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
   819 to extern(_table).  The plain name entry path is superceded by a
   820 general 'naming' context, which also includes the 'policy' to produce
   821 a fully qualified name and external accesses of a fully qualified
   822 name; NameSpace.extend is superceded by context dependent
   823 Sign.declare_name.  Several theory and proof context operations modify
   824 the naming context.  Especially note Theory.restore_naming and
   825 ProofContext.restore_naming to get back to a sane state; note that
   826 Theory.add_path is no longer sufficient to recover from
   827 Theory.absolute_path in particular.
   828 
   829 * Pure: new flags short_names (default false) and unique_names
   830 (default true) for controlling output of qualified names.  If
   831 short_names is set, names are printed unqualified.  If unique_names is
   832 reset, the name prefix is reduced to the minimum required to achieve
   833 the original result when interning again, even if there is an overlap
   834 with earlier declarations.
   835 
   836 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
   837 now 'extend', and 'merge' gets an additional Pretty.pp argument
   838 (useful for printing error messages).  INCOMPATIBILITY.
   839 
   840 * Pure: major reorganization of the theory context.  Type Sign.sg and
   841 Theory.theory are now identified, referring to the universal
   842 Context.theory (see Pure/context.ML).  Actual signature and theory
   843 content is managed as theory data.  The old code and interfaces were
   844 spread over many files and structures; the new arrangement introduces
   845 considerable INCOMPATIBILITY to gain more clarity:
   846 
   847   Context -- theory management operations (name, identity, inclusion,
   848     parents, ancestors, merge, etc.), plus generic theory data;
   849 
   850   Sign -- logical signature and syntax operations (declaring consts,
   851     types, etc.), plus certify/read for common entities;
   852 
   853   Theory -- logical theory operations (stating axioms, definitions,
   854     oracles), plus a copy of logical signature operations (consts,
   855     types, etc.); also a few basic management operations (Theory.copy,
   856     Theory.merge, etc.)
   857 
   858 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
   859 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
   860 for convenience -- they merely return the theory.
   861 
   862 * Pure: type Type.tsig is superceded by theory in most interfaces.
   863 
   864 * Pure: the Isar proof context type is already defined early in Pure
   865 as Context.proof (note that ProofContext.context and Proof.context are
   866 aliases, where the latter is the preferred name).  This enables other
   867 Isabelle components to refer to that type even before Isar is present.
   868 
   869 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
   870 typeK, constK, axiomK, oracleK), but provide explicit operations for
   871 any of these kinds.  For example, Sign.intern typeK is now
   872 Sign.intern_type, Theory.hide_space Sign.typeK is now
   873 Theory.hide_types.  Also note that former
   874 Theory.hide_classes/types/consts are now
   875 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
   876 internalize their arguments!  INCOMPATIBILITY.
   877 
   878 * Pure: get_thm interface (of PureThy and ProofContext) expects
   879 datatype thmref (with constructors Name and NameSelection) instead of
   880 plain string -- INCOMPATIBILITY;
   881 
   882 * Pure: cases produced by proof methods specify options, where NONE
   883 means to remove case bindings -- INCOMPATIBILITY in
   884 (RAW_)METHOD_CASES.
   885 
   886 * Pure: the following operations retrieve axioms or theorems from a
   887 theory node or theory hierarchy, respectively:
   888 
   889   Theory.axioms_of: theory -> (string * term) list
   890   Theory.all_axioms_of: theory -> (string * term) list
   891   PureThy.thms_of: theory -> (string * thm) list
   892   PureThy.all_thms_of: theory -> (string * thm) list
   893 
   894 * Pure: print_tac now outputs the goal through the trace channel.
   895 
   896 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
   897 Reference Toplevel.debug (default false) controls detailed printing
   898 and tracing of low-level exceptions; Toplevel.profiling (default 0)
   899 controls execution profiling -- set to 1 for time and 2 for space
   900 (both increase the runtime).
   901 
   902 * Isar session: The initial use of ROOT.ML is now always timed,
   903 i.e. the log will show the actual process times, in contrast to the
   904 elapsed wall-clock time that the outer shell wrapper produces.
   905 
   906 * Simplifier: improved handling of bound variables (nameless
   907 representation, avoid allocating new strings).  Simprocs that invoke
   908 the Simplifier recursively should use Simplifier.inherit_bounds to
   909 avoid local name clashes.
   910 
   911 * Provers: Simplifier and Classical Reasoner now support proof context
   912 dependent plug-ins (simprocs, solvers, wrappers etc.).  These extra
   913 components are stored in the theory and patched into the
   914 simpset/claset when used in an Isar proof context.  Context dependent
   915 components are maintained by the following theory operations:
   916 
   917   Simplifier.add_context_simprocs
   918   Simplifier.del_context_simprocs
   919   Simplifier.set_context_subgoaler
   920   Simplifier.reset_context_subgoaler
   921   Simplifier.add_context_looper
   922   Simplifier.del_context_looper
   923   Simplifier.add_context_unsafe_solver
   924   Simplifier.add_context_safe_solver
   925 
   926   Classical.add_context_safe_wrapper
   927   Classical.del_context_safe_wrapper
   928   Classical.add_context_unsafe_wrapper
   929   Classical.del_context_unsafe_wrapper
   930 
   931 IMPORTANT NOTE: proof tools (methods etc.) need to use
   932 local_simpset_of and local_claset_of to instead of the primitive
   933 Simplifier.get_local_simpset and Classical.get_local_claset,
   934 respectively, in order to see the context dependent fields!
   935 
   936 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
   937 bindings for all theorems stored within a given theory; this may help
   938 in porting non-Isar theories to Isar ones, while keeping ML proof
   939 scripts for the time being.
   940 
   941 * ML operator HTML.with_charset specifies the charset begin used for
   942 generated HTML files.  For example:
   943 
   944   HTML.with_charset "utf-8" use_thy "Hebrew";
   945   HTML.with_charset "utf-8" use_thy "Chinese";
   946 
   947 
   948 *** System ***
   949 
   950 * Allow symlinks to all proper Isabelle executables (Isabelle,
   951 isabelle, isatool etc.).
   952 
   953 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
   954 isatool doc, isatool mkdir, display_drafts etc.).
   955 
   956 * isatool usedir: option -f allows specification of the ML file to be
   957 used by Isabelle; default is ROOT.ML.
   958 
   959 * New isatool version outputs the version identifier of the Isabelle
   960 distribution being used.
   961 
   962 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
   963 (containing Boolean satisfiability problems) into Isabelle/HOL
   964 theories.
   965 
   966 
   967 
   968 New in Isabelle2004 (April 2004)
   969 --------------------------------
   970 
   971 *** General ***
   972 
   973 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
   974   Replaces linorder.ML.
   975 
   976 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
   977   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
   978   (\<a>...\<z>), are now considered normal letters, and can therefore
   979   be used anywhere where an ASCII letter (a...zA...Z) has until
   980   now. COMPATIBILITY: This obviously changes the parsing of some
   981   terms, especially where a symbol has been used as a binder, say
   982   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
   983   as an identifier.  Fix it by inserting a space around former
   984   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
   985   existing theory and ML files.
   986 
   987 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
   988 
   989 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
   990   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
   991   a normal (but invisible) letter. For multiple letter subscripts repeat
   992   \<^isub> like this: x\<^isub>1\<^isub>2.
   993 
   994 * Pure: There are now sub-/superscripts that can span more than one
   995   character. Text between \<^bsub> and \<^esub> is set in subscript in
   996   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
   997   superscript. The new control characters are not identifier parts.
   998 
   999 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  1000   content of "..." to the latex file instead of \isacntrl... . The "..."
  1001   may consist of any printable characters excluding the end bracket >.
  1002 
  1003 * Pure: Using new Isar command "finalconsts" (or the ML functions
  1004   Theory.add_finals or Theory.add_finals_i) it is now possible to
  1005   declare constants "final", which prevents their being given a definition
  1006   later.  It is useful for constants whose behaviour is fixed axiomatically
  1007   rather than definitionally, such as the meta-logic connectives.
  1008 
  1009 * Pure: 'instance' now handles general arities with general sorts
  1010   (i.e. intersections of classes),
  1011 
  1012 * Presentation: generated HTML now uses a CSS style sheet to make layout
  1013   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  1014   It can be changed to alter the colors/layout of generated pages.
  1015 
  1016 
  1017 *** Isar ***
  1018 
  1019 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  1020   cut_tac, subgoal_tac and thin_tac:
  1021   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  1022     locales are no longer forced to write Isar proof scripts.
  1023     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  1024     emulations.
  1025   - INCOMPATIBILITY: names of variables to be instantiated may no
  1026     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  1027     This is consistent with the instantiation attribute "where".
  1028 
  1029 * Attributes "where" and "of":
  1030   - Now take type variables of instantiated theorem into account when reading
  1031     the instantiation string.  This fixes a bug that caused instantiated
  1032     theorems to have too special types in some circumstances.
  1033   - "where" permits explicit instantiations of type variables.
  1034 
  1035 * Calculation commands "moreover" and "also" no longer interfere with
  1036   current facts ("this"), admitting arbitrary combinations with "then"
  1037   and derived forms.
  1038 
  1039 * Locales:
  1040   - Goal statements involving the context element "includes" no longer
  1041     generate theorems with internal delta predicates (those ending on
  1042     "_axioms") in the premise.
  1043     Resolve particular premise with <locale>.intro to obtain old form.
  1044   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  1045     specification and "includes" elements in goal statement.
  1046   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  1047     [intro?] and [elim?] (respectively) by default.
  1048   - Experimental command for instantiation of locales in proof contexts:
  1049         instantiate <label>[<attrs>]: <loc>
  1050     Instantiates locale <loc> and adds all its theorems to the current context
  1051     taking into account their attributes.  Label and attrs are optional
  1052     modifiers, like in theorem declarations.  If present, names of
  1053     instantiated theorems are qualified with <label>, and the attributes
  1054     <attrs> are applied after any attributes these theorems might have already.
  1055       If the locale has assumptions, a chained fact of the form
  1056     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  1057     are derived.  The command does not support old-style locales declared
  1058     with "locale (open)".
  1059       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  1060 
  1061 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  1062   (Isar) contexts.
  1063 
  1064 
  1065 *** HOL ***
  1066 
  1067 * Proof import: new image HOL4 contains the imported library from
  1068   the HOL4 system with about 2500 theorems. It is imported by
  1069   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  1070   can be used like any other Isabelle image.  See
  1071   HOL/Import/HOL/README for more information.
  1072 
  1073 * Simplifier:
  1074   - Much improved handling of linear and partial orders.
  1075     Reasoners for linear and partial orders are set up for type classes
  1076     "linorder" and "order" respectively, and are added to the default simpset
  1077     as solvers.  This means that the simplifier can build transitivity chains
  1078     to solve goals from the assumptions.
  1079   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  1080     of blast or auto after simplification become unnecessary because the goal
  1081     is solved by simplification already.
  1082 
  1083 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  1084     all proved in axiomatic type classes for semirings, rings and fields.
  1085 
  1086 * Numerics:
  1087   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  1088     now formalized using the Ring_and_Field theory mentioned above.
  1089   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  1090     than before, because now they are set up once in a generic manner.
  1091   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  1092     Look for the general versions in Ring_and_Field (and Power if they concern
  1093     exponentiation).
  1094 
  1095 * Type "rat" of the rational numbers is now available in HOL-Complex.
  1096 
  1097 * Records:
  1098   - Record types are now by default printed with their type abbreviation
  1099     instead of the list of all field types. This can be configured via
  1100     the reference "print_record_type_abbr".
  1101   - Simproc "record_upd_simproc" for simplification of multiple updates added
  1102     (not enabled by default).
  1103   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  1104     EX x. x = sel r to True (not enabled by default).
  1105   - Tactic "record_split_simp_tac" to split and simplify records added.
  1106 
  1107 * 'specification' command added, allowing for definition by
  1108   specification.  There is also an 'ax_specification' command that
  1109   introduces the new constants axiomatically.
  1110 
  1111 * arith(_tac) is now able to generate counterexamples for reals as well.
  1112 
  1113 * HOL-Algebra: new locale "ring" for non-commutative rings.
  1114 
  1115 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  1116   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  1117 
  1118 * HOL-Matrix: a first theory for matrices in HOL with an application of
  1119   matrix theory to linear programming.
  1120 
  1121 * Unions and Intersections:
  1122   The latex output syntax of UN and INT has been changed
  1123   from "\Union x \in A. B" to "\Union_{x \in A} B"
  1124   i.e. the index formulae has become a subscript.
  1125   Similarly for "\Union x. B", and for \Inter instead of \Union.
  1126 
  1127 * Unions and Intersections over Intervals:
  1128   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  1129   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  1130   like in normal math, and corresponding versions for < and for intersection.
  1131 
  1132 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  1133   lexicographic dictonary ordering has been added as "lexord".
  1134 
  1135 * ML: the legacy theory structures Int and List have been removed. They had
  1136   conflicted with ML Basis Library structures having the same names.
  1137 
  1138 * 'refute' command added to search for (finite) countermodels.  Only works
  1139   for a fragment of HOL.  The installation of an external SAT solver is
  1140   highly recommended.  See "HOL/Refute.thy" for details.
  1141 
  1142 * 'quickcheck' command: Allows to find counterexamples by evaluating
  1143   formulae under an assignment of free variables to random values.
  1144   In contrast to 'refute', it can deal with inductive datatypes,
  1145   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  1146   for examples.
  1147 
  1148 
  1149 *** HOLCF ***
  1150 
  1151 * Streams now come with concatenation and are part of the HOLCF image
  1152 
  1153 
  1154 
  1155 New in Isabelle2003 (May 2003)
  1156 ------------------------------
  1157 
  1158 *** General ***
  1159 
  1160 * Provers/simplifier:
  1161 
  1162   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  1163     Assumptions are now subject to complete mutual simplification,
  1164     not just from left to right. The simplifier now preserves
  1165     the order of assumptions.
  1166 
  1167     Potential INCOMPATIBILITY:
  1168 
  1169     -- simp sometimes diverges where the old version did
  1170        not, e.g. invoking simp on the goal
  1171 
  1172         [| P (f x); y = x; f x = f y |] ==> Q
  1173 
  1174        now gives rise to the infinite reduction sequence
  1175 
  1176         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  1177 
  1178        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  1179        kind of problem.
  1180 
  1181     -- Tactics combining classical reasoner and simplification (such as auto)
  1182        are also affected by this change, because many of them rely on
  1183        simp. They may sometimes diverge as well or yield a different numbers
  1184        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  1185        in case of problems. Sometimes subsequent calls to the classical
  1186        reasoner will fail because a preceeding call to the simplifier too
  1187        eagerly simplified the goal, e.g. deleted redundant premises.
  1188 
  1189   - The simplifier trace now shows the names of the applied rewrite rules
  1190 
  1191   - You can limit the number of recursive invocations of the simplifier
  1192     during conditional rewriting (where the simplifie tries to solve the
  1193     conditions before applying the rewrite rule):
  1194     ML "simp_depth_limit := n"
  1195     where n is an integer. Thus you can force termination where previously
  1196     the simplifier would diverge.
  1197 
  1198   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  1199 
  1200   - No longer aborts on failed congruence proof.  Instead, the
  1201     congruence is ignored.
  1202 
  1203 * Pure: New generic framework for extracting programs from constructive
  1204   proofs. See HOL/Extraction.thy for an example instantiation, as well
  1205   as HOL/Extraction for some case studies.
  1206 
  1207 * Pure: The main goal of the proof state is no longer shown by default, only
  1208 the subgoals. This behaviour is controlled by a new flag.
  1209    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  1210 (ML: Proof.show_main_goal).
  1211 
  1212 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  1213 rules whose conclusion matches subgoal 1:
  1214       PG menu: Isabelle/Isar -> Show me -> matching rules
  1215 The rules are ordered by how closely they match the subgoal.
  1216 In particular, rules that solve a subgoal outright are displayed first
  1217 (or rather last, the way they are printed).
  1218 (ML: ProofGeneral.print_intros())
  1219 
  1220 * Pure: New flag trace_unify_fail causes unification to print
  1221 diagnostic information (PG: in trace buffer) when it fails. This is
  1222 useful for figuring out why single step proofs like rule, erule or
  1223 assumption failed.
  1224 
  1225 * Pure: Locale specifications now produce predicate definitions
  1226 according to the body of text (covering assumptions modulo local
  1227 definitions); predicate "loc_axioms" covers newly introduced text,
  1228 while "loc" is cumulative wrt. all included locale expressions; the
  1229 latter view is presented only on export into the global theory
  1230 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  1231 on the old view without predicates;
  1232 
  1233 * Pure: predefined locales "var" and "struct" are useful for sharing
  1234 parameters (as in CASL, for example); just specify something like
  1235 ``var x + var y + struct M'' as import;
  1236 
  1237 * Pure: improved thms_containing: proper indexing of facts instead of
  1238 raw theorems; check validity of results wrt. current name space;
  1239 include local facts of proof configuration (also covers active
  1240 locales), cover fixed variables in index; may use "_" in term
  1241 specification; an optional limit for the number of printed facts may
  1242 be given (the default is 40);
  1243 
  1244 * Pure: disallow duplicate fact bindings within new-style theory files
  1245 (batch-mode only);
  1246 
  1247 * Provers: improved induct method: assumptions introduced by case
  1248 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  1249 the goal statement); "foo" still refers to all facts collectively;
  1250 
  1251 * Provers: the function blast.overloaded has been removed: all constants
  1252 are regarded as potentially overloaded, which improves robustness in exchange
  1253 for slight decrease in efficiency;
  1254 
  1255 * Provers/linorder: New generic prover for transitivity reasoning over
  1256 linear orders.  Note: this prover is not efficient!
  1257 
  1258 * Isar: preview of problems to finish 'show' now produce an error
  1259 rather than just a warning (in interactive mode);
  1260 
  1261 
  1262 *** HOL ***
  1263 
  1264 * arith(_tac)
  1265 
  1266  - Produces a counter example if it cannot prove a goal.
  1267    Note that the counter example may be spurious if the goal is not a formula
  1268    of quantifier-free linear arithmetic.
  1269    In ProofGeneral the counter example appears in the trace buffer.
  1270 
  1271  - Knows about div k and mod k where k is a numeral of type nat or int.
  1272 
  1273  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  1274    linear arithmetic fails. This takes account of quantifiers and divisibility.
  1275    Presburger arithmetic can also be called explicitly via presburger(_tac).
  1276 
  1277 * simp's arithmetic capabilities have been enhanced a bit: it now
  1278 takes ~= in premises into account (by performing a case split);
  1279 
  1280 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  1281 are distributed over a sum of terms;
  1282 
  1283 * New tactic "trans_tac" and method "trans" instantiate
  1284 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  1285 "<=", "<" and "=").
  1286 
  1287 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  1288 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  1289 
  1290 * 'typedef' command has new option "open" to suppress the set
  1291 definition;
  1292 
  1293 * functions Min and Max on finite sets have been introduced (theory
  1294 Finite_Set);
  1295 
  1296 * attribute [symmetric] now works for relations as well; it turns
  1297 (x,y) : R^-1 into (y,x) : R, and vice versa;
  1298 
  1299 * induct over a !!-quantified statement (say !!x1..xn):
  1300   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  1301 
  1302 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  1303 %x. None. Warning: empty_def now refers to the previously hidden definition
  1304 of the empty set.
  1305 
  1306 * Algebra: formalization of classical algebra.  Intended as base for
  1307 any algebraic development in Isabelle.  Currently covers group theory
  1308 (up to Sylow's theorem) and ring theory (Universal Property of
  1309 Univariate Polynomials).  Contributions welcome;
  1310 
  1311 * GroupTheory: deleted, since its material has been moved to Algebra;
  1312 
  1313 * Complex: new directory of the complex numbers with numeric constants,
  1314 nonstandard complex numbers, and some complex analysis, standard and
  1315 nonstandard (Jacques Fleuriot);
  1316 
  1317 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  1318 
  1319 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  1320 Fleuriot);
  1321 
  1322 * Real/HahnBanach: updated and adapted to locales;
  1323 
  1324 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  1325 Gray and Kramer);
  1326 
  1327 * UNITY: added the Meier-Sanders theory of progress sets;
  1328 
  1329 * MicroJava: bytecode verifier and lightweight bytecode verifier
  1330 as abstract algorithms, instantiated to the JVM;
  1331 
  1332 * Bali: Java source language formalization. Type system, operational
  1333 semantics, axiomatic semantics. Supported language features:
  1334 classes, interfaces, objects,virtual methods, static methods,
  1335 static/instance fields, arrays, access modifiers, definite
  1336 assignment, exceptions.
  1337 
  1338 
  1339 *** ZF ***
  1340 
  1341 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  1342 universe, etc.);
  1343 
  1344 * Main ZF: virtually all theories converted to new-style format;
  1345 
  1346 
  1347 *** ML ***
  1348 
  1349 * Pure: Tactic.prove provides sane interface for internal proofs;
  1350 omits the infamous "standard" operation, so this is more appropriate
  1351 than prove_goalw_cterm in many situations (e.g. in simprocs);
  1352 
  1353 * Pure: improved error reporting of simprocs;
  1354 
  1355 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  1356 up simprocs;
  1357 
  1358 
  1359 *** Document preparation ***
  1360 
  1361 * uses \par instead of \\ for line breaks in theory text. This may
  1362 shift some page breaks in large documents. To get the old behaviour
  1363 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  1364 
  1365 * minimized dependencies of isabelle.sty and isabellesym.sty on
  1366 other packages
  1367 
  1368 * \<euro> now needs package babel/greek instead of marvosym (which
  1369 broke \Rightarrow)
  1370 
  1371 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  1372 textcomp package)
  1373 
  1374 
  1375 
  1376 New in Isabelle2002 (March 2002)
  1377 --------------------------------
  1378 
  1379 *** Document preparation ***
  1380 
  1381 * greatly simplified document preparation setup, including more
  1382 graceful interpretation of isatool usedir -i/-d/-D options, and more
  1383 instructive isatool mkdir; users should basically be able to get
  1384 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  1385 users may run a separate document processing stage manually like this:
  1386 "isatool usedir -D output HOL Test && isatool document Test/output";
  1387 
  1388 * theory dependency graph may now be incorporated into documents;
  1389 isatool usedir -g true will produce session_graph.eps/.pdf for use
  1390 with \includegraphics of LaTeX;
  1391 
  1392 * proper spacing of consecutive markup elements, especially text
  1393 blocks after section headings;
  1394 
  1395 * support bold style (for single symbols only), input syntax is like
  1396 this: "\<^bold>\<alpha>" or "\<^bold>A";
  1397 
  1398 * \<bullet> is now output as bold \cdot by default, which looks much
  1399 better in printed text;
  1400 
  1401 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  1402 note that these symbols are currently unavailable in Proof General /
  1403 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  1404 
  1405 * isatool latex no longer depends on changed TEXINPUTS, instead
  1406 isatool document copies the Isabelle style files to the target
  1407 location;
  1408 
  1409 
  1410 *** Isar ***
  1411 
  1412 * Pure/Provers: improved proof by cases and induction;
  1413   - 'case' command admits impromptu naming of parameters (such as
  1414     "case (Suc n)");
  1415   - 'induct' method divinates rule instantiation from the inductive
  1416     claim; no longer requires excessive ?P bindings for proper
  1417     instantiation of cases;
  1418   - 'induct' method properly enumerates all possibilities of set/type
  1419     rules; as a consequence facts may be also passed through *type*
  1420     rules without further ado;
  1421   - 'induct' method now derives symbolic cases from the *rulified*
  1422     rule (before it used to rulify cases stemming from the internal
  1423     atomized version); this means that the context of a non-atomic
  1424     statement becomes is included in the hypothesis, avoiding the
  1425     slightly cumbersome show "PROP ?case" form;
  1426   - 'induct' may now use elim-style induction rules without chaining
  1427     facts, using ``missing'' premises from the goal state; this allows
  1428     rules stemming from inductive sets to be applied in unstructured
  1429     scripts, while still benefitting from proper handling of non-atomic
  1430     statements; NB: major inductive premises need to be put first, all
  1431     the rest of the goal is passed through the induction;
  1432   - 'induct' proper support for mutual induction involving non-atomic
  1433     rule statements (uses the new concept of simultaneous goals, see
  1434     below);
  1435   - append all possible rule selections, but only use the first
  1436     success (no backtracking);
  1437   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  1438   - undeclared rule case names default to numbers 1, 2, 3, ...;
  1439   - added 'print_induct_rules' (covered by help item in recent Proof
  1440     General versions);
  1441   - moved induct/cases attributes to Pure, methods to Provers;
  1442   - generic method setup instantiated for FOL and HOL;
  1443 
  1444 * Pure: support multiple simultaneous goal statements, for example
  1445 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  1446 meta-level mechanism, this acts as if several individual goals had
  1447 been stated separately; in particular common proof methods need to be
  1448 repeated in order to cover all claims; note that a single elimination
  1449 step is *not* sufficient to establish the two conjunctions, so this
  1450 fails:
  1451 
  1452   assume "A & B" then have A and B ..   (*".." fails*)
  1453 
  1454 better use "obtain" in situations as above; alternative refer to
  1455 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  1456 
  1457 * Pure: proper integration with ``locales''; unlike the original
  1458 version by Florian Kammller, Isar locales package high-level proof
  1459 contexts rather than raw logical ones (e.g. we admit to include
  1460 attributes everywhere); operations on locales include merge and
  1461 rename; support for implicit arguments (``structures''); simultaneous
  1462 type-inference over imports and text; see also HOL/ex/Locales.thy for
  1463 some examples;
  1464 
  1465 * Pure: the following commands have been ``localized'', supporting a
  1466 target locale specification "(in name)": 'lemma', 'theorem',
  1467 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  1468 stored both within the locale and at the theory level (exported and
  1469 qualified by the locale name);
  1470 
  1471 * Pure: theory goals may now be specified in ``long'' form, with
  1472 ad-hoc contexts consisting of arbitrary locale elements. for example
  1473 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  1474 definitions may be given, too); the result is a meta-level rule with
  1475 the context elements being discharged in the obvious way;
  1476 
  1477 * Pure: new proof command 'using' allows to augment currently used
  1478 facts after a goal statement ('using' is syntactically analogous to
  1479 'apply', but acts on the goal's facts only); this allows chained facts
  1480 to be separated into parts given before and after a claim, as in
  1481 ``from a and b have C using d and e <proof>'';
  1482 
  1483 * Pure: renamed "antecedent" case to "rule_context";
  1484 
  1485 * Pure: new 'judgment' command records explicit information about the
  1486 object-logic embedding (used by several tools internally); no longer
  1487 use hard-wired "Trueprop";
  1488 
  1489 * Pure: added 'corollary' command;
  1490 
  1491 * Pure: fixed 'token_translation' command;
  1492 
  1493 * Pure: removed obsolete 'exported' attribute;
  1494 
  1495 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  1496 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  1497 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  1498 
  1499 * Pure: method 'atomize' presents local goal premises as object-level
  1500 statements (atomic meta-level propositions); setup controlled via
  1501 rewrite rules declarations of 'atomize' attribute; example
  1502 application: 'induct' method with proper rule statements in improper
  1503 proof *scripts*;
  1504 
  1505 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  1506 now consider the syntactic context of assumptions, giving a better
  1507 chance to get type-inference of the arguments right (this is
  1508 especially important for locales);
  1509 
  1510 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  1511 mode;
  1512 
  1513 * Pure/obtain: the formal conclusion "thesis", being marked as
  1514 ``internal'', may no longer be reference directly in the text;
  1515 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  1516 situations;
  1517 
  1518 * Pure: generic 'sym' attribute which declares a rule both as pure
  1519 'elim?' and for the 'symmetric' operation;
  1520 
  1521 * Pure: marginal comments ``--'' may now occur just anywhere in the
  1522 text; the fixed correlation with particular command syntax has been
  1523 discontinued;
  1524 
  1525 * Pure: new method 'rules' is particularly well-suited for proof
  1526 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  1527 but often produces more compact proof terms with less detours;
  1528 
  1529 * Pure/Provers/classical: simplified integration with pure rule
  1530 attributes and methods; the classical "intro?/elim?/dest?"
  1531 declarations coincide with the pure ones; the "rule" method no longer
  1532 includes classically swapped intros; "intro" and "elim" methods no
  1533 longer pick rules from the context; also got rid of ML declarations
  1534 AddXIs/AddXEs/AddXDs; all of this has some potential for
  1535 INCOMPATIBILITY;
  1536 
  1537 * Provers/classical: attribute 'swapped' produces classical inversions
  1538 of introduction rules;
  1539 
  1540 * Provers/simplifier: 'simplified' attribute may refer to explicit
  1541 rules instead of full simplifier context; 'iff' attribute handles
  1542 conditional rules;
  1543 
  1544 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  1545 
  1546 * HOL: 'recdef' now fails on unfinished automated proofs, use
  1547 "(permissive)" option to recover old behavior;
  1548 
  1549 * HOL: 'inductive' no longer features separate (collective) attributes
  1550 for 'intros' (was found too confusing);
  1551 
  1552 * HOL: properly declared induction rules less_induct and
  1553 wf_induct_rule;
  1554 
  1555 
  1556 *** HOL ***
  1557 
  1558 * HOL: moved over to sane numeral syntax; the new policy is as
  1559 follows:
  1560 
  1561   - 0 and 1 are polymorphic constants, which are defined on any
  1562   numeric type (nat, int, real etc.);
  1563 
  1564   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  1565   binary representation internally;
  1566 
  1567   - type nat has special constructor Suc, and generally prefers Suc 0
  1568   over 1::nat and Suc (Suc 0) over 2::nat;
  1569 
  1570 This change may cause significant problems of INCOMPATIBILITY; here
  1571 are some hints on converting existing sources:
  1572 
  1573   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  1574   entities, so expressions involving "-" (unary or binary minus) need
  1575   to be spaced properly;
  1576 
  1577   - existing occurrences of "1" may need to be constraint "1::nat" or
  1578   even replaced by Suc 0; similar for old "2";
  1579 
  1580   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  1581 
  1582   - remove all special provisions on numerals in proofs;
  1583 
  1584 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  1585 representation (depends on bin_arith_simps in the default context);
  1586 
  1587 * HOL: symbolic syntax for x^2 (numeral 2);
  1588 
  1589 * HOL: the class of all HOL types is now called "type" rather than
  1590 "term"; INCOMPATIBILITY, need to adapt references to this type class
  1591 in axclass/classes, instance/arities, and (usually rare) occurrences
  1592 in typings (of consts etc.); internally the class is called
  1593 "HOL.type", ML programs should refer to HOLogic.typeS;
  1594 
  1595 * HOL/record package improvements:
  1596   - new derived operations "fields" to build a partial record section,
  1597     "extend" to promote a fixed record to a record scheme, and
  1598     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  1599     declared as simp by default;
  1600   - shared operations ("more", "fields", etc.) now need to be always
  1601     qualified) --- potential INCOMPATIBILITY;
  1602   - removed "make_scheme" operations (use "make" with "extend") --
  1603     INCOMPATIBILITY;
  1604   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  1605   - provides cases/induct rules for use with corresponding Isar
  1606     methods (for concrete records, record schemes, concrete more
  1607     parts, and schematic more parts -- in that order);
  1608   - internal definitions directly based on a light-weight abstract
  1609     theory of product types over typedef rather than datatype;
  1610 
  1611 * HOL: generic code generator for generating executable ML code from
  1612 specifications; specific support for HOL constructs such as inductive
  1613 datatypes and sets, as well as recursive functions; can be invoked
  1614 via 'generate_code' theory section;
  1615 
  1616 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  1617 
  1618 * HOL: consolidated and renamed several theories.  In particular:
  1619         Ord.thy has been absorbed into HOL.thy
  1620         String.thy has been absorbed into List.thy
  1621 
  1622 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  1623 (beware of argument permutation!);
  1624 
  1625 * HOL: linorder_less_split superseded by linorder_cases;
  1626 
  1627 * HOL/List: "nodups" renamed to "distinct";
  1628 
  1629 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  1630 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  1631   - Ex_def has changed, now need to use some_eq_ex
  1632 
  1633 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  1634 in this (rare) case use:
  1635 
  1636   delSWrapper "split_all_tac"
  1637   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  1638 
  1639 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  1640 MAY FAIL;
  1641 
  1642 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  1643 Isabelle's type classes, ^ on functions and relations has too general
  1644 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  1645 necessary to attach explicit type constraints;
  1646 
  1647 * HOL/Relation: the prefix name of the infix "O" has been changed from
  1648 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  1649 renamed accordingly (eg "compI" -> "rel_compI").
  1650 
  1651 * HOL: syntax translations now work properly with numerals and records
  1652 expressions;
  1653 
  1654 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  1655 of "lam" -- INCOMPATIBILITY;
  1656 
  1657 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  1658 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  1659 renamed "Product_Type.unit";
  1660 
  1661 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  1662 
  1663 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  1664 the "cases" method);
  1665 
  1666 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  1667 Florian Kammller);
  1668 
  1669 * HOL/IMP: updated and converted to new-style theory format; several
  1670 parts turned into readable document, with proper Isar proof texts and
  1671 some explanations (by Gerwin Klein);
  1672 
  1673 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  1674 
  1675 * HOL-Hyperreal is now a logic image;
  1676 
  1677 
  1678 *** HOLCF ***
  1679 
  1680 * Isar: consts/constdefs supports mixfix syntax for continuous
  1681 operations;
  1682 
  1683 * Isar: domain package adapted to new-style theory format, e.g. see
  1684 HOLCF/ex/Dnat.thy;
  1685 
  1686 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  1687 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  1688 lift.induct_tac, always use UU instead of Undef;
  1689 
  1690 * HOLCF/IMP: updated and converted to new-style theory;
  1691 
  1692 
  1693 *** ZF ***
  1694 
  1695 * Isar: proper integration of logic-specific tools and packages,
  1696 including theory commands '(co)inductive', '(co)datatype',
  1697 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  1698 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  1699 
  1700 * theory Main no longer includes AC; for the Axiom of Choice, base
  1701 your theory on Main_ZFC;
  1702 
  1703 * the integer library now covers quotients and remainders, with many
  1704 laws relating division to addition, multiplication, etc.;
  1705 
  1706 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  1707 typeless version of the formalism;
  1708 
  1709 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  1710 format;
  1711 
  1712 * ZF/Induct: new directory for examples of inductive definitions,
  1713 including theory Multiset for multiset orderings; converted to
  1714 new-style theory format;
  1715 
  1716 * ZF: many new theorems about lists, ordinals, etc.;
  1717 
  1718 
  1719 *** General ***
  1720 
  1721 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  1722 variable proof controls level of detail: 0 = no proofs (only oracle
  1723 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  1724 also ref manual for further ML interfaces;
  1725 
  1726 * Pure/axclass: removed obsolete ML interface
  1727 goal_subclass/goal_arity;
  1728 
  1729 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  1730 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  1731 separate tokens, so expressions involving minus need to be spaced
  1732 properly;
  1733 
  1734 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  1735 rather than "infixl" or "infixr";
  1736 
  1737 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  1738 sort constraint specifications in type inference; e.g. "x::_::foo"
  1739 ensures that the type of "x" is of sort "foo" (but not necessarily a
  1740 type variable);
  1741 
  1742 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  1743 control output of nested => (types); the default behavior is
  1744 "type_brackets";
  1745 
  1746 * Pure/syntax: builtin parse translation for "_constify" turns valued
  1747 tokens into AST constants;
  1748 
  1749 * Pure/syntax: prefer later declarations of translations and print
  1750 translation functions; potential INCOMPATIBILITY: need to reverse
  1751 multiple declarations for same syntax element constant;
  1752 
  1753 * Pure/show_hyps reset by default (in accordance to existing Isar
  1754 practice);
  1755 
  1756 * Provers/classical: renamed addaltern to addafter, addSaltern to
  1757 addSafter;
  1758 
  1759 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  1760 as well;
  1761 
  1762 * system: tested support for MacOS X; should be able to get Isabelle +
  1763 Proof General to work in a plain Terminal after installing Poly/ML
  1764 (e.g. from the Isabelle distribution area) and GNU bash alone
  1765 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  1766 support requires further installations, e.g. from
  1767 http://fink.sourceforge.net/);
  1768 
  1769 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  1770 
  1771 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  1772 of 40 MB), cf. ML_OPTIONS;
  1773 
  1774 * system: Proof General keywords specification is now part of the
  1775 Isabelle distribution (see etc/isar-keywords.el);
  1776 
  1777 * system: support for persistent Proof General sessions (refrain from
  1778 outdating all loaded theories on startup); user may create writable
  1779 logic images like this: ``isabelle -q HOL Test'';
  1780 
  1781 * system: smart selection of Isabelle process versus Isabelle
  1782 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  1783 run both "isabelle" and "Isabelle" even if file names are badly
  1784 damaged (executable inspects the case of the first letter of its own
  1785 name); added separate "isabelle-process" and "isabelle-interface";
  1786 
  1787 * system: refrain from any attempt at filtering input streams; no
  1788 longer support ``8bit'' encoding of old isabelle font, instead proper
  1789 iso-latin characters may now be used; the related isatools
  1790 "symbolinput" and "nonascii" have disappeared as well;
  1791 
  1792 * system: removed old "xterm" interface (the print modes "xterm" and
  1793 "xterm_color" are still available for direct use in a suitable
  1794 terminal);
  1795 
  1796 
  1797 
  1798 New in Isabelle99-2 (February 2001)
  1799 -----------------------------------
  1800 
  1801 *** Overview of INCOMPATIBILITIES ***
  1802 
  1803 * HOL: please note that theories in the Library and elsewhere often use the
  1804 new-style (Isar) format; to refer to their theorems in an ML script you must
  1805 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  1806 
  1807 * HOL: inductive package no longer splits induction rule aggressively,
  1808 but only as far as specified by the introductions given; the old
  1809 format may be recovered via ML function complete_split_rule or attribute
  1810 'split_rule (complete)';
  1811 
  1812 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  1813 gfp_Tarski to gfp_unfold;
  1814 
  1815 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  1816 
  1817 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  1818 relation); infix "^^" has been renamed "``"; infix "``" has been
  1819 renamed "`"; "univalent" has been renamed "single_valued";
  1820 
  1821 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  1822 operation;
  1823 
  1824 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  1825 
  1826 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  1827 
  1828 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  1829 consequence, it is no longer monotonic wrt. the local goal context
  1830 (which is now passed through the inductive cases);
  1831 
  1832 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  1833 \<gg> to \<ggreater>;
  1834 
  1835 
  1836 *** Document preparation ***
  1837 
  1838 * \isabellestyle{NAME} selects version of Isabelle output (currently
  1839 available: are "it" for near math-mode best-style output, "sl" for
  1840 slanted text style, and "tt" for plain type-writer; if no
  1841 \isabellestyle command is given, output is according to slanted
  1842 type-writer);
  1843 
  1844 * support sub/super scripts (for single symbols only), input syntax is
  1845 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  1846 
  1847 * some more standard symbols; see Appendix A of the system manual for
  1848 the complete list of symbols defined in isabellesym.sty;
  1849 
  1850 * improved isabelle style files; more abstract symbol implementation
  1851 (should now use \isamath{...} and \isatext{...} in custom symbol
  1852 definitions);
  1853 
  1854 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  1855 state; Note that presentation of goal states does not conform to
  1856 actual human-readable proof documents.  Please do not include goal
  1857 states into document output unless you really know what you are doing!
  1858 
  1859 * proper indentation of antiquoted output with proportional LaTeX
  1860 fonts;
  1861 
  1862 * no_document ML operator temporarily disables LaTeX document
  1863 generation;
  1864 
  1865 * isatool unsymbolize tunes sources for plain ASCII communication;
  1866 
  1867 
  1868 *** Isar ***
  1869 
  1870 * Pure: Isar now suffers initial goal statements to contain unbound
  1871 schematic variables (this does not conform to actual readable proof
  1872 documents, due to unpredictable outcome and non-compositional proof
  1873 checking); users who know what they are doing may use schematic goals
  1874 for Prolog-style synthesis of proven results;
  1875 
  1876 * Pure: assumption method (an implicit finishing) now handles actual
  1877 rules as well;
  1878 
  1879 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  1880 initial goal, declare "that" only as Pure intro (only for single
  1881 steps); the "that" rule assumption may now be involved in implicit
  1882 finishing, thus ".." becomes a feasible for trivial obtains;
  1883 
  1884 * Pure: default proof step now includes 'intro_classes'; thus trivial
  1885 instance proofs may be performed by "..";
  1886 
  1887 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  1888 statements as well;
  1889 
  1890 * Pure: more robust selection of calculational rules;
  1891 
  1892 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  1893 rule (as well as the assumption rule);
  1894 
  1895 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  1896 lemmas, using the graph browser tool;
  1897 
  1898 * Pure: predict failure of "show" in interactive mode;
  1899 
  1900 * Pure: 'thms_containing' now takes actual terms as arguments;
  1901 
  1902 * HOL: improved method 'induct' --- now handles non-atomic goals
  1903 (potential INCOMPATIBILITY); tuned error handling;
  1904 
  1905 * HOL: cases and induct rules now provide explicit hints about the
  1906 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  1907 any remaining facts are inserted into the goal verbatim;
  1908 
  1909 * HOL: local contexts (aka cases) may now contain term bindings as
  1910 well; the 'cases' and 'induct' methods new provide a ?case binding for
  1911 the result to be shown in each case;
  1912 
  1913 * HOL: added 'recdef_tc' command;
  1914 
  1915 * isatool convert assists in eliminating legacy ML scripts;
  1916 
  1917 
  1918 *** HOL ***
  1919 
  1920 * HOL/Library: a collection of generic theories to be used together
  1921 with main HOL; the theory loader path already includes this directory
  1922 by default; the following existing theories have been moved here:
  1923 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  1924 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  1925 
  1926 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  1927 modelling and verification task performed in Isabelle/HOL +
  1928 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  1929 
  1930 * HOL/Algebra: special summation operator SUM no longer exists, it has
  1931 been replaced by setsum; infix 'assoc' now has priority 50 (like
  1932 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  1933 'domain', this makes the theory consistent with mathematical
  1934 literature;
  1935 
  1936 * HOL basics: added overloaded operations "inverse" and "divide"
  1937 (infix "/"), syntax for generic "abs" operation, generic summation
  1938 operator \<Sum>;
  1939 
  1940 * HOL/typedef: simplified package, provide more useful rules (see also
  1941 HOL/subset.thy);
  1942 
  1943 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  1944 now expressed as a proper nested rule (old-style tactic scripts may
  1945 require atomize_strip_tac to cope with non-atomic premises);
  1946 
  1947 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  1948 to "split_conv" (old name still available for compatibility);
  1949 
  1950 * HOL: improved concrete syntax for strings (e.g. allows translation
  1951 rules with string literals);
  1952 
  1953 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  1954  and Fleuriot's mechanization of analysis, including the transcendental
  1955  functions for the reals;
  1956 
  1957 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  1958 
  1959 
  1960 *** CTT ***
  1961 
  1962 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  1963 "lam" is displayed as TWO lambda-symbols
  1964 
  1965 * CTT: theory Main now available, containing everything (that is, Bool
  1966 and Arith);
  1967 
  1968 
  1969 *** General ***
  1970 
  1971 * Pure: the Simplifier has been implemented properly as a derived rule
  1972 outside of the actual kernel (at last!); the overall performance
  1973 penalty in practical applications is about 50%, while reliability of
  1974 the Isabelle inference kernel has been greatly improved;
  1975 
  1976 * print modes "brackets" and "no_brackets" control output of nested =>
  1977 (types) and ==> (props); the default behaviour is "brackets";
  1978 
  1979 * Provers: fast_tac (and friends) now handle actual object-logic rules
  1980 as assumptions as well;
  1981 
  1982 * system: support Poly/ML 4.0;
  1983 
  1984 * system: isatool install handles KDE version 1 or 2;
  1985 
  1986 
  1987 
  1988 New in Isabelle99-1 (October 2000)
  1989 ----------------------------------
  1990 
  1991 *** Overview of INCOMPATIBILITIES ***
  1992 
  1993 * HOL: simplification of natural numbers is much changed; to partly
  1994 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  1995 issue the following ML commands:
  1996 
  1997   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  1998   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  1999 
  2000 * HOL: simplification no longer dives into case-expressions; this is
  2001 controlled by "t.weak_case_cong" for each datatype t;
  2002 
  2003 * HOL: nat_less_induct renamed to less_induct;
  2004 
  2005 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  2006 fixsome to patch .thy and .ML sources automatically;
  2007 
  2008   select_equality  -> some_equality
  2009   select_eq_Ex     -> some_eq_ex
  2010   selectI2EX       -> someI2_ex
  2011   selectI2         -> someI2
  2012   selectI          -> someI
  2013   select1_equality -> some1_equality
  2014   Eps_sym_eq       -> some_sym_eq_trivial
  2015   Eps_eq           -> some_eq_trivial
  2016 
  2017 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  2018 
  2019 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  2020 instead);
  2021 
  2022 * HOL: the recursion equations generated by 'recdef' are now called
  2023 f.simps instead of f.rules;
  2024 
  2025 * HOL: qed_spec_mp now also handles bounded ALL as well;
  2026 
  2027 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  2028 sometimes be needed;
  2029 
  2030 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  2031 
  2032 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  2033 
  2034 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  2035 product is now "<*>" instead of "Times"; the lexicographic product is
  2036 now "<*lex*>" instead of "**";
  2037 
  2038 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  2039 of main HOL, but was unused); better use HOL's datatype package;
  2040 
  2041 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  2042 the old syntax may be recovered as follows:
  2043 
  2044   syntax (symbols)
  2045     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  2046       (infixl "\\<oplus>" 100)
  2047 
  2048 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  2049 
  2050 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  2051 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  2052 internally;
  2053 
  2054 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  2055 changed from A/r to A//r;
  2056 
  2057 * ZF: new treatment of arithmetic (nat & int) may break some old
  2058 proofs;
  2059 
  2060 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  2061 rulify -> rule_format, elimify -> elim_format, ...);
  2062 
  2063 * Isar/Provers: intro/elim/dest attributes changed; renamed
  2064 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  2065 should have to change intro!! to intro? only); replaced "delrule" by
  2066 "rule del";
  2067 
  2068 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  2069 
  2070 * Provers: strengthened force_tac by using new first_best_tac;
  2071 
  2072 * LaTeX document preparation: several changes of isabelle.sty (see
  2073 lib/texinputs);
  2074 
  2075 
  2076 *** Document preparation ***
  2077 
  2078 * formal comments (text blocks etc.) in new-style theories may now
  2079 contain antiquotations of thm/prop/term/typ/text to be presented
  2080 according to latex print mode; concrete syntax is like this:
  2081 @{term[show_types] "f(x) = a + x"};
  2082 
  2083 * isatool mkdir provides easy setup of Isabelle session directories,
  2084 including proper document sources;
  2085 
  2086 * generated LaTeX sources are now deleted after successful run
  2087 (isatool document -c); may retain a copy somewhere else via -D option
  2088 of isatool usedir;
  2089 
  2090 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  2091 style files, achieving self-contained LaTeX sources and simplifying
  2092 LaTeX debugging;
  2093 
  2094 * old-style theories now produce (crude) LaTeX output as well;
  2095 
  2096 * browser info session directories are now self-contained (may be put
  2097 on WWW server seperately); improved graphs of nested sessions; removed
  2098 graph for 'all sessions';
  2099 
  2100 * several improvements in isabelle style files; \isabellestyle{it}
  2101 produces fake math mode output; \isamarkupheader is now \section by
  2102 default; see lib/texinputs/isabelle.sty etc.;
  2103 
  2104 
  2105 *** Isar ***
  2106 
  2107 * Isar/Pure: local results and corresponding term bindings are now
  2108 subject to Hindley-Milner polymorphism (similar to ML); this
  2109 accommodates incremental type-inference very nicely;
  2110 
  2111 * Isar/Pure: new derived language element 'obtain' supports
  2112 generalized existence reasoning;
  2113 
  2114 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  2115 support accumulation of results, without applying any rules yet;
  2116 useful to collect intermediate results without explicit name
  2117 references, and for use with transitivity rules with more than 2
  2118 premises;
  2119 
  2120 * Isar/Pure: scalable support for case-analysis type proofs: new
  2121 'case' language element refers to local contexts symbolically, as
  2122 produced by certain proof methods; internally, case names are attached
  2123 to theorems as "tags";
  2124 
  2125 * Isar/Pure: theory command 'hide' removes declarations from
  2126 class/type/const name spaces;
  2127 
  2128 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  2129 indicate potential overloading;
  2130 
  2131 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  2132 
  2133 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  2134 "{a,b,c}" instead of {a,b,c};
  2135 
  2136 * Isar/Pure now provides its own version of intro/elim/dest
  2137 attributes; useful for building new logics, but beware of confusion
  2138 with the version in Provers/classical;
  2139 
  2140 * Isar/Pure: the local context of (non-atomic) goals is provided via
  2141 case name 'antecedent';
  2142 
  2143 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  2144 to the current context is now done automatically);
  2145 
  2146 * Isar/Pure: theory command 'method_setup' provides a simple interface
  2147 for definining proof methods in ML;
  2148 
  2149 * Isar/Provers: intro/elim/dest attributes changed; renamed
  2150 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  2151 most cases, one should have to change intro!! to intro? only);
  2152 replaced "delrule" by "rule del";
  2153 
  2154 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  2155 'symmetric' attribute (the latter supercedes [RS sym]);
  2156 
  2157 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  2158 method modifier); 'simp' method: 'only:' modifier removes loopers as
  2159 well (including splits);
  2160 
  2161 * Isar/Provers: Simplifier and Classical methods now support all kind
  2162 of modifiers used in the past, including 'cong', 'iff', etc.
  2163 
  2164 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  2165 of Simplifier and Classical reasoner);
  2166 
  2167 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  2168 now support named cases; major packages (inductive, datatype, primrec,
  2169 recdef) support case names and properly name parameters;
  2170 
  2171 * Isar/HOL: new transitivity rules for substitution in inequalities --
  2172 monotonicity conditions are extracted to be proven at end of
  2173 calculations;
  2174 
  2175 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  2176 method anyway;
  2177 
  2178 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  2179 split_if split_if_asm; datatype package provides theorems foo.splits =
  2180 foo.split foo.split_asm for each datatype;
  2181 
  2182 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  2183 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  2184 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  2185 use "(cases (simplified))" method in proper proof texts);
  2186 
  2187 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  2188 
  2189 * Isar: names of theorems etc. may be natural numbers as well;
  2190 
  2191 * Isar: 'pr' command: optional arguments for goals_limit and
  2192 ProofContext.prems_limit; no longer prints theory contexts, but only
  2193 proof states;
  2194 
  2195 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  2196 additional print modes to be specified; e.g. "pr(latex)" will print
  2197 proof state according to the Isabelle LaTeX style;
  2198 
  2199 * Isar: improved support for emulating tactic scripts, including proof
  2200 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  2201 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  2202 (for HOL datatypes);
  2203 
  2204 * Isar: simplified (more robust) goal selection of proof methods: 1st
  2205 goal, all goals, or explicit goal specifier (tactic emulation); thus
  2206 'proof method scripts' have to be in depth-first order;
  2207 
  2208 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  2209 
  2210 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  2211 should instead use individual commands for printing items
  2212 (print_commands, print_methods etc.);
  2213 
  2214 * Isar: added 'nothing' --- the empty list of theorems;
  2215 
  2216 
  2217 *** HOL ***
  2218 
  2219 * HOL/MicroJava: formalization of a fragment of Java, together with a
  2220 corresponding virtual machine and a specification of its bytecode
  2221 verifier and a lightweight bytecode verifier, including proofs of
  2222 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  2223 Cornelia Pusch (see also the homepage of project Bali at
  2224 http://isabelle.in.tum.de/Bali/);
  2225 
  2226 * HOL/Algebra: new theory of rings and univariate polynomials, by
  2227 Clemens Ballarin;
  2228 
  2229 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  2230 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  2231 Rasmussen;
  2232 
  2233 * HOL/Lattice: fundamental concepts of lattice theory and order
  2234 structures, including duals, properties of bounds versus algebraic
  2235 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  2236 Theorem for complete lattices etc.; may also serve as a demonstration
  2237 for abstract algebraic reasoning using axiomatic type classes, and
  2238 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  2239 
  2240 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  2241 von Oheimb;
  2242 
  2243 * HOL/IMPP: extension of IMP with local variables and mutually
  2244 recursive procedures, by David von Oheimb;
  2245 
  2246 * HOL/Lambda: converted into new-style theory and document;
  2247 
  2248 * HOL/ex/Multiquote: example of multiple nested quotations and
  2249 anti-quotations -- basically a generalized version of de-Bruijn
  2250 representation; very useful in avoiding lifting of operations;
  2251 
  2252 * HOL/record: added general record equality rule to simpset; fixed
  2253 select-update simplification procedure to handle extended records as
  2254 well; admit "r" as field name;
  2255 
  2256 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  2257 other numeric types and also as the identity of groups, rings, etc.;
  2258 
  2259 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  2260 Types nat and int belong to this axclass;
  2261 
  2262 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  2263    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  2264    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  2265   two terms #m*u and #n*u are replaced by #(m+n)*u
  2266     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  2267   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  2268     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  2269 
  2270 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  2271 powerful prover for predicate logic but knows nothing of clasets; see
  2272 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  2273 
  2274 * HOL: new version of "case_tac" subsumes both boolean case split and
  2275 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  2276 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  2277 
  2278 * HOL: simplification no longer dives into case-expressions: only the
  2279 selector expression is simplified, but not the remaining arms; to
  2280 enable full simplification of case-expressions for datatype t, you may
  2281 remove t.weak_case_cong from the simpset, either globally (Delcongs
  2282 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  2283 
  2284 * HOL/recdef: the recursion equations generated by 'recdef' for
  2285 function 'f' are now called f.simps instead of f.rules; if all
  2286 termination conditions are proved automatically, these simplification
  2287 rules are added to the simpset, as in primrec; rules may be named
  2288 individually as well, resulting in a separate list of theorems for
  2289 each equation;
  2290 
  2291 * HOL/While is a new theory that provides a while-combinator. It
  2292 permits the definition of tail-recursive functions without the
  2293 provision of a termination measure. The latter is necessary once the
  2294 invariant proof rule for while is applied.
  2295 
  2296 * HOL: new (overloaded) notation for the set of elements below/above
  2297 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  2298 
  2299 * HOL: theorems impI, allI, ballI bound as "strip";
  2300 
  2301 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  2302 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  2303 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  2304 
  2305 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  2306 
  2307 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  2308 main HOL, but was unused);
  2309 
  2310 * HOL: fewer consts declared as global (e.g. have to refer to
  2311 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  2312 
  2313 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  2314 in case of overlap with user translations (e.g. judgements over
  2315 tuples); (note that the underlying logical represenation is still
  2316 bogus);
  2317 
  2318 
  2319 *** ZF ***
  2320 
  2321 * ZF: simplification automatically cancels common terms in arithmetic
  2322 expressions over nat and int;
  2323 
  2324 * ZF: new treatment of nat to minimize type-checking: all operators
  2325 coerce their operands to a natural number using the function natify,
  2326 making the algebraic laws unconditional;
  2327 
  2328 * ZF: as above, for int: operators coerce their operands to an integer
  2329 using the function intify;
  2330 
  2331 * ZF: the integer library now contains many of the usual laws for the
  2332 orderings, including $<=, and monotonicity laws for $+ and $*;
  2333 
  2334 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  2335 simplification;
  2336 
  2337 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  2338 to the simplifier and classical reasoner simultaneously;
  2339 
  2340 
  2341 *** General ***
  2342 
  2343 * Provers: blast_tac now handles actual object-logic rules as
  2344 assumptions; note that auto_tac uses blast_tac internally as well;
  2345 
  2346 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  2347 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  2348 
  2349 * Provers: delrules now handles destruct rules as well (no longer need
  2350 explicit make_elim);
  2351 
  2352 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  2353   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  2354 use instead the strong form,
  2355   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  2356 in HOL, FOL and ZF the function cla_make_elim will create such rules
  2357 from destruct-rules;
  2358 
  2359 * Provers: Simplifier.easy_setup provides a fast path to basic
  2360 Simplifier setup for new object-logics;
  2361 
  2362 * Pure: AST translation rules no longer require constant head on LHS;
  2363 
  2364 * Pure: improved name spaces: ambiguous output is qualified; support
  2365 for hiding of names;
  2366 
  2367 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  2368 XSYMBOL_HOME; no longer need to do manual configuration in most
  2369 situations;
  2370 
  2371 * system: compression of ML heaps images may now be controlled via -c
  2372 option of isabelle and isatool usedir (currently only observed by
  2373 Poly/ML);
  2374 
  2375 * system: isatool installfonts may handle X-Symbol fonts as well (very
  2376 useful for remote X11);
  2377 
  2378 * system: provide TAGS file for Isabelle sources;
  2379 
  2380 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  2381 order;
  2382 
  2383 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  2384 timing flag supersedes proof_timing and Toplevel.trace;
  2385 
  2386 * ML: new combinators |>> and |>>> for incremental transformations
  2387 with secondary results (e.g. certain theory extensions):
  2388 
  2389 * ML: PureThy.add_defs gets additional argument to indicate potential
  2390 overloading (usually false);
  2391 
  2392 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  2393 results;
  2394 
  2395 
  2396 
  2397 New in Isabelle99 (October 1999)
  2398 --------------------------------
  2399 
  2400 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  2401 
  2402 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  2403 are no longer simplified.  (This allows the simplifier to unfold recursive
  2404 functional programs.)  To restore the old behaviour, declare
  2405 
  2406     Delcongs [if_weak_cong];
  2407 
  2408 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  2409 complement;
  2410 
  2411 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  2412 
  2413 * HOL/datatype: mutual_induct_tac no longer exists --
  2414   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  2415 
  2416 * HOL/typedef: fixed type inference for representing set; type
  2417 arguments now have to occur explicitly on the rhs as type constraints;
  2418 
  2419 * ZF: The con_defs part of an inductive definition may no longer refer
  2420 to constants declared in the same theory;
  2421 
  2422 * HOL, ZF: the function mk_cases, generated by the inductive
  2423 definition package, has lost an argument.  To simplify its result, it
  2424 uses the default simpset instead of a supplied list of theorems.
  2425 
  2426 * HOL/List: the constructors of type list are now Nil and Cons;
  2427 
  2428 * Simplifier: the type of the infix ML functions
  2429         setSSolver addSSolver setSolver addSolver
  2430 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  2431 for packaging solvers. A solver is created via
  2432         mk_solver: string -> (thm list -> int -> tactic) -> solver
  2433 where the string argument is only a comment.
  2434 
  2435 
  2436 *** Proof tools ***
  2437 
  2438 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  2439 decision procedure for linear arithmetic. Currently it is used for
  2440 types `nat', `int', and `real' in HOL (see below); it can, should and
  2441 will be instantiated for other types and logics as well.
  2442 
  2443 * The simplifier now accepts rewrite rules with flexible heads, eg
  2444      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  2445   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  2446   matching.
  2447 
  2448 
  2449 *** General ***
  2450 
  2451 * New Isabelle/Isar subsystem provides an alternative to traditional
  2452 tactical theorem proving; together with the ProofGeneral/isar user
  2453 interface it offers an interactive environment for developing human
  2454 readable proof documents (Isar == Intelligible semi-automated
  2455 reasoning); for further information see isatool doc isar-ref,
  2456 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  2457 
  2458 * improved and simplified presentation of theories: better HTML markup
  2459 (including colors), graph views in several sizes; isatool usedir now
  2460 provides a proper interface for user theories (via -P option); actual
  2461 document preparation based on (PDF)LaTeX is available as well (for
  2462 new-style theories only); see isatool doc system for more information;
  2463 
  2464 * native support for Proof General, both for classic Isabelle and
  2465 Isabelle/Isar;
  2466 
  2467 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  2468 using the graph browser tool;
  2469 
  2470 * Isabelle manuals now also available as PDF;
  2471 
  2472 * theory loader rewritten from scratch (may not be fully
  2473 bug-compatible); old loadpath variable has been replaced by show_path,
  2474 add_path, del_path, reset_path functions; new operations such as
  2475 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  2476 isatool doc ref);
  2477 
  2478 * improved isatool install: option -k creates KDE application icon,
  2479 option -p DIR installs standalone binaries;
  2480 
  2481 * added ML_PLATFORM setting (useful for cross-platform installations);
  2482 more robust handling of platform specific ML images for SML/NJ;
  2483 
  2484 * the settings environment is now statically scoped, i.e. it is never
  2485 created again in sub-processes invoked from isabelle, isatool, or
  2486 Isabelle;
  2487 
  2488 * path element specification '~~' refers to '$ISABELLE_HOME';
  2489 
  2490 * in locales, the "assumes" and "defines" parts may be omitted if
  2491 empty;
  2492 
  2493 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  2494 long arrows);
  2495 
  2496 * new print_mode "HTML";
  2497 
  2498 * new flag show_tags controls display of tags of theorems (which are
  2499 basically just comments that may be attached by some tools);
  2500 
  2501 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  2502 mode and goal output format:
  2503 
  2504 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  2505 244c244
  2506 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  2507 ---
  2508 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  2509 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  2510 181c181
  2511 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  2512 ---
  2513 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  2514 
  2515 * function bind_thms stores lists of theorems (cf. bind_thm);
  2516 
  2517 * new shorthand tactics ftac, eatac, datac, fatac;
  2518 
  2519 * qed (and friends) now accept "" as result name; in that case the
  2520 theorem is not stored, but proper checks and presentation of the
  2521 result still apply;
  2522 
  2523 * theorem database now also indexes constants "Trueprop", "all",
  2524 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  2525 
  2526 
  2527 *** HOL ***
  2528 
  2529 ** HOL arithmetic **
  2530 
  2531 * There are now decision procedures for linear arithmetic over nat and
  2532 int:
  2533 
  2534 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  2535 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  2536 are treated as atomic; subformulae not involving type `nat' or `int'
  2537 are ignored; quantified subformulae are ignored unless they are
  2538 positive universal or negative existential. The tactic has to be
  2539 invoked by hand and can be a little bit slow. In particular, the
  2540 running time is exponential in the number of occurrences of `min' and
  2541 `max', and `-' on `nat'.
  2542 
  2543 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  2544 (negated) (in)equalities among the premises and the conclusion into
  2545 account (i.e. no compound formulae) and does not know about `min' and
  2546 `max', and `-' on `nat'. It is fast and is used automatically by the
  2547 simplifier.
  2548 
  2549 NB: At the moment, these decision procedures do not cope with mixed
  2550 nat/int formulae where the two parts interact, such as `m < n ==>
  2551 int(m) < int(n)'.
  2552 
  2553 * HOL/Numeral provides a generic theory of numerals (encoded
  2554 efficiently as bit strings); setup for types nat/int/real is in place;
  2555 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  2556 int, existing theories and proof scripts may require a few additional
  2557 type constraints;
  2558 
  2559 * integer division and remainder can now be performed on constant
  2560 arguments;
  2561 
  2562 * many properties of integer multiplication, division and remainder
  2563 are now available;
  2564 
  2565 * An interface to the Stanford Validity Checker (SVC) is available through the
  2566 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  2567 are proved automatically.  SVC must be installed separately, and its results
  2568 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  2569 invocation of the underlying oracle).  For SVC see
  2570   http://verify.stanford.edu/SVC
  2571 
  2572 * IsaMakefile: the HOL-Real target now builds an actual image;
  2573 
  2574 
  2575 ** HOL misc **
  2576 
  2577 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  2578 (in Isabelle/Isar) -- by Gertrud Bauer;
  2579 
  2580 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  2581 analysis for assembly languages with subtypes;
  2582 
  2583 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  2584 -- avoids syntactic ambiguities and treats state, transition, and
  2585 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  2586 changed syntax and (many) tactics;
  2587 
  2588 * HOL/inductive: Now also handles more general introduction rules such
  2589   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  2590   theorems are now maintained within the theory (maintained via the
  2591   "mono" attribute);
  2592 
  2593 * HOL/datatype: Now also handles arbitrarily branching datatypes
  2594   (using function types) such as
  2595 
  2596   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  2597 
  2598 * HOL/record: record_simproc (part of the default simpset) takes care
  2599 of selectors applied to updated records; record_split_tac is no longer
  2600 part of the default claset; update_defs may now be removed from the
  2601 simpset in many cases; COMPATIBILITY: old behavior achieved by
  2602 
  2603   claset_ref () := claset() addSWrapper record_split_wrapper;
  2604   Delsimprocs [record_simproc]
  2605 
  2606 * HOL/typedef: fixed type inference for representing set; type
  2607 arguments now have to occur explicitly on the rhs as type constraints;
  2608 
  2609 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  2610 names rather than an ML expression;
  2611 
  2612 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  2613 supplied later.  Program schemes can be defined, such as
  2614     "While B C s = (if B s then While B C (C s) else s)"
  2615 where the well-founded relation can be chosen after B and C have been given.
  2616 
  2617 * HOL/List: the constructors of type list are now Nil and Cons;
  2618 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  2619 course, ML tools referring to List.list.op # etc. have to be adapted;
  2620 
  2621 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  2622 disabled by default; run isabelle with option -m HOL to get back to
  2623 the original Gordon/HOL-style output;
  2624 
  2625 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  2626 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  2627 
  2628 * HOL basic syntax simplified (more orthogonal): all variants of
  2629 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  2630 Eps operator is provided as well: "SOME x. P[x]";
  2631 
  2632 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  2633 
  2634 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  2635 thus available for user theories;
  2636 
  2637 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  2638 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  2639 time;
  2640 
  2641 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  2642 several times and then mp;
  2643 
  2644 
  2645 *** LK ***
  2646 
  2647 * the notation <<...>> is now available as a notation for sequences of
  2648 formulas;
  2649 
  2650 * the simplifier is now installed
  2651 
  2652 * the axiom system has been generalized (thanks to Soren Heilmann)
  2653 
  2654 * the classical reasoner now has a default rule database
  2655 
  2656 
  2657 *** ZF ***
  2658 
  2659 * new primrec section allows primitive recursive functions to be given
  2660 directly (as in HOL) over datatypes and the natural numbers;
  2661 
  2662 * new tactics induct_tac and exhaust_tac for induction (or case
  2663 analysis) over datatypes and the natural numbers;
  2664 
  2665 * the datatype declaration of type T now defines the recursor T_rec;
  2666 
  2667 * simplification automatically does freeness reasoning for datatype
  2668 constructors;
  2669 
  2670 * automatic type-inference, with AddTCs command to insert new
  2671 type-checking rules;
  2672 
  2673 * datatype introduction rules are now added as Safe Introduction rules
  2674 to the claset;
  2675 
  2676 * the syntax "if P then x else y" is now available in addition to
  2677 if(P,x,y);
  2678 
  2679 
  2680 *** Internal programming interfaces ***
  2681 
  2682 * tuned simplifier trace output; new flag debug_simp;
  2683 
  2684 * structures Vartab / Termtab (instances of TableFun) offer efficient
  2685 tables indexed by indexname_ord / term_ord (compatible with aconv);
  2686 
  2687 * AxClass.axclass_tac lost the theory argument;
  2688 
  2689 * tuned current_goals_markers semantics: begin / end goal avoids
  2690 printing empty lines;
  2691 
  2692 * removed prs and prs_fn hook, which was broken because it did not
  2693 include \n in its semantics, forcing writeln to add one
  2694 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  2695 string -> unit if you really want to output text without newline;
  2696 
  2697 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  2698 plain output, interface builders may have to enable 'isabelle_font'
  2699 mode to get Isabelle font glyphs as before;
  2700 
  2701 * refined token_translation interface; INCOMPATIBILITY: output length
  2702 now of type real instead of int;
  2703 
  2704 * theory loader actions may be traced via new ThyInfo.add_hook
  2705 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  2706 your own database of information attached to *whole* theories -- as
  2707 opposed to intra-theory data slots offered via TheoryDataFun;
  2708 
  2709 * proper handling of dangling sort hypotheses (at last!);
  2710 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  2711 extra sort hypotheses that can be witnessed from the type signature;
  2712 the force_strip_shyps flag is gone, any remaining shyps are simply
  2713 left in the theorem (with a warning issued by strip_shyps_warning);
  2714 
  2715 
  2716 
  2717 New in Isabelle98-1 (October 1998)
  2718 ----------------------------------
  2719 
  2720 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  2721 
  2722 * several changes of automated proof tools;
  2723 
  2724 * HOL: major changes to the inductive and datatype packages, including
  2725 some minor incompatibilities of theory syntax;
  2726 
  2727 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  2728 called `inj_on';
  2729 
  2730 * HOL: removed duplicate thms in Arith:
  2731   less_imp_add_less  should be replaced by  trans_less_add1
  2732   le_imp_add_le      should be replaced by  trans_le_add1
  2733 
  2734 * HOL: unary minus is now overloaded (new type constraints may be
  2735 required);
  2736 
  2737 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  2738 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  2739 now taken as an integer constant.
  2740 
  2741 * Pure: ML function 'theory_of' renamed to 'theory';
  2742 
  2743 
  2744 *** Proof tools ***
  2745 
  2746 * Simplifier:
  2747   1. Asm_full_simp_tac is now more aggressive.
  2748      1. It will sometimes reorient premises if that increases their power to
  2749         simplify.
  2750      2. It does no longer proceed strictly from left to right but may also
  2751         rotate premises to achieve further simplification.
  2752      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  2753      old Asm_full_simp_tac in that it does not rotate premises.
  2754   2. The simplifier now knows a little bit about nat-arithmetic.
  2755 
  2756 * Classical reasoner: wrapper mechanism for the classical reasoner now
  2757 allows for selected deletion of wrappers, by introduction of names for
  2758 wrapper functionals.  This implies that addbefore, addSbefore,
  2759 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  2760 and that adding two tactics with the same name overwrites the first
  2761 one (emitting a warning).
  2762   type wrapper = (int -> tactic) -> (int -> tactic)
  2763   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  2764   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  2765   delWrapper, delSWrapper: claset *  string            -> claset
  2766   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  2767 
  2768 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  2769 semantics; addbefore now affects only the unsafe part of step_tac
  2770 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  2771 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  2772 by Force_tac;
  2773 
  2774 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  2775 compWrapper; added safe wrapper (and access functions for it);
  2776 
  2777 * HOL/split_all_tac is now much faster and fails if there is nothing
  2778 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  2779 and the names of the automatically generated variables have changed.
  2780 split_all_tac has moved within claset() from unsafe wrappers to safe
  2781 wrappers, which means that !!-bound variables are split much more
  2782 aggressively, and safe_tac and clarify_tac now split such variables.
  2783 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  2784 Note: the same holds for record_split_tac, which does the job of
  2785 split_all_tac for record fields.
  2786 
  2787 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  2788 permanently to the default simpset using Addsplits just like
  2789 Addsimps. They can be removed via Delsplits just like
  2790 Delsimps. Lower-case versions are also available.
  2791 
  2792 * HOL/Simplifier: The rule split_if is now part of the default
  2793 simpset. This means that the simplifier will eliminate all occurrences
  2794 of if-then-else in the conclusion of a goal. To prevent this, you can
  2795 either remove split_if completely from the default simpset by
  2796 `Delsplits [split_if]' or remove it in a specific call of the
  2797 simplifier using `... delsplits [split_if]'.  You can also add/delete
  2798 other case splitting rules to/from the default simpset: every datatype
  2799 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  2800 t is the name of the datatype).
  2801 
  2802 * Classical reasoner / Simplifier combination: new force_tac (and
  2803 derivatives Force_tac, force) combines rewriting and classical
  2804 reasoning (and whatever other tools) similarly to auto_tac, but is
  2805 aimed to solve the given subgoal completely.
  2806 
  2807 
  2808 *** General ***
  2809 
  2810 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  2811 and `goalw': the theory is no longer needed as an explicit argument -
  2812 the current theory context is used; assumptions are no longer returned
  2813 at the ML-level unless one of them starts with ==> or !!; it is
  2814 recommended to convert to these new commands using isatool fixgoal
  2815 (backup your sources first!);
  2816 
  2817 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  2818 the current theory context, and 'theory' to lookup stored theories;
  2819 
  2820 * new theory section 'locale' for declaring constants, assumptions and
  2821 definitions that have local scope;
  2822 
  2823 * new theory section 'nonterminals' for purely syntactic types;
  2824 
  2825 * new theory section 'setup' for generic ML setup functions
  2826 (e.g. package initialization);
  2827 
  2828 * the distribution now includes Isabelle icons: see
  2829 lib/logo/isabelle-{small,tiny}.xpm;
  2830 
  2831 * isatool install - install binaries with absolute references to
  2832 ISABELLE_HOME/bin;
  2833 
  2834 * isatool logo -- create instances of the Isabelle logo (as EPS);
  2835 
  2836 * print mode 'emacs' reserved for Isamode;
  2837 
  2838 * support multiple print (ast) translations per constant name;
  2839 
  2840 * theorems involving oracles are now printed with a suffixed [!];
  2841 
  2842 
  2843 *** HOL ***
  2844 
  2845 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  2846 
  2847 * HOL/inductive package reorganized and improved: now supports mutual
  2848 definitions such as
  2849 
  2850   inductive EVEN ODD
  2851     intrs
  2852       null "0 : EVEN"
  2853       oddI "n : EVEN ==> Suc n : ODD"
  2854       evenI "n : ODD ==> Suc n : EVEN"
  2855 
  2856 new theorem list "elims" contains an elimination rule for each of the
  2857 recursive sets; inductive definitions now handle disjunctive premises
  2858 correctly (also ZF);
  2859 
  2860 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  2861 "mutual_induct" no longer exists - the induction rule is always
  2862 contained in "induct";
  2863 
  2864 
  2865 * HOL/datatype package re-implemented and greatly improved: now
  2866 supports mutually recursive datatypes such as
  2867 
  2868   datatype
  2869     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  2870             | SUM ('a aexp) ('a aexp)
  2871             | DIFF ('a aexp) ('a aexp)
  2872             | NUM 'a
  2873   and
  2874     'a bexp = LESS ('a aexp) ('a aexp)
  2875             | AND ('a bexp) ('a bexp)
  2876             | OR ('a bexp) ('a bexp)
  2877 
  2878 as well as indirectly recursive datatypes such as
  2879 
  2880   datatype
  2881     ('a, 'b) term = Var 'a
  2882                   | App 'b ((('a, 'b) term) list)
  2883 
  2884 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  2885 induction on mutually / indirectly recursive datatypes.
  2886 
  2887 Primrec equations are now stored in theory and can be accessed via
  2888 <function_name>.simps.
  2889 
  2890 INCOMPATIBILITIES:
  2891 
  2892   - Theories using datatypes must now have theory Datatype as an
  2893     ancestor.
  2894   - The specific <typename>.induct_tac no longer exists - use the
  2895     generic induct_tac instead.
  2896   - natE has been renamed to nat.exhaust - use exhaust_tac
  2897     instead of res_inst_tac ... natE. Note that the variable
  2898     names in nat.exhaust differ from the names in natE, this
  2899     may cause some "fragile" proofs to fail.
  2900   - The theorems split_<typename>_case and split_<typename>_case_asm
  2901     have been renamed to <typename>.split and <typename>.split_asm.
  2902   - Since default sorts of type variables are now handled correctly,
  2903     some datatype definitions may have to be annotated with explicit
  2904     sort constraints.
  2905   - Primrec definitions no longer require function name and type
  2906     of recursive argument.
  2907 
  2908 Consider using isatool fixdatatype to adapt your theories and proof
  2909 scripts to the new package (backup your sources first!).
  2910 
  2911 
  2912 * HOL/record package: considerably improved implementation; now
  2913 includes concrete syntax for record types, terms, updates; theorems
  2914 for surjective pairing and splitting !!-bound record variables; proof
  2915 support is as follows:
  2916 
  2917   1) standard conversions (selectors or updates applied to record
  2918 constructor terms) are part of the standard simpset;
  2919 
  2920   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  2921 made part of standard simpset and claset via addIffs;
  2922 
  2923   3) a tactic for record field splitting (record_split_tac) is part of
  2924 the standard claset (addSWrapper);
  2925 
  2926 To get a better idea about these rules you may retrieve them via
  2927 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  2928 the name of your record type.
  2929 
  2930 The split tactic 3) conceptually simplifies by the following rule:
  2931 
  2932   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  2933 
  2934 Thus any record variable that is bound by meta-all will automatically
  2935 blow up into some record constructor term, consequently the
  2936 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  2937 solve record problems automatically.
  2938 
  2939 
  2940 * reorganized the main HOL image: HOL/Integ and String loaded by
  2941 default; theory Main includes everything;
  2942 
  2943 * automatic simplification of integer sums and comparisons, using cancellation;
  2944 
  2945 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  2946 
  2947 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  2948 
  2949 * many new identities for unions, intersections, set difference, etc.;
  2950 
  2951 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  2952 called split_if, split_split, split_sum_case and split_nat_case (to go
  2953 with add/delsplits);
  2954 
  2955 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  2956 (?x::unit) = (); this is made part of the default simpset, which COULD
  2957 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  2958 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  2959 unit_abs_eta_conv is added in order to counter the effect of
  2960 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  2961 %u.f();
  2962 
  2963 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  2964 makes more sense);
  2965 
  2966 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  2967   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  2968   disjointness reasoning but breaking a few old proofs.
  2969 
  2970 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  2971 to 'converse' from 'inverse' (for compatibility with ZF and some
  2972 literature);
  2973 
  2974 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  2975 the well-founded relation;
  2976 
  2977 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  2978     Compl A.  The "Compl" syntax remains available as input syntax for this
  2979     release ONLY.
  2980 
  2981 * HOL/Update: new theory of function updates:
  2982     f(a:=b) == %x. if x=a then b else f x
  2983 may also be iterated as in f(a:=b,c:=d,...);
  2984 
  2985 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  2986 
  2987 * HOL/List:
  2988   - new function list_update written xs[i:=v] that updates the i-th
  2989     list position. May also be iterated as in xs[i:=a,j:=b,...].
  2990   - new function `upt' written [i..j(] which generates the list
  2991     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  2992     bound write [i..j], which is a shorthand for [i..j+1(].
  2993   - new lexicographic orderings and corresponding wellfoundedness theorems.
  2994 
  2995 * HOL/Arith:
  2996   - removed 'pred' (predecessor) function;
  2997   - generalized some theorems about n-1;
  2998   - many new laws about "div" and "mod";
  2999   - new laws about greatest common divisors (see theory ex/Primes);
  3000 
  3001 * HOL/Relation: renamed the relational operator r^-1 "converse"
  3002 instead of "inverse";
  3003 
  3004 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  3005   of the multiset ordering;
  3006 
  3007 * directory HOL/Real: a construction of the reals using Dedekind cuts
  3008   (not included by default);
  3009 
  3010 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  3011 
  3012 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  3013   programs, i.e. different program variables may have different types.
  3014 
  3015 * calling (stac rew i) now fails if "rew" has no effect on the goal
  3016   [previously, this check worked only if the rewrite rule was unconditional]
  3017   Now rew can involve either definitions or equalities (either == or =).
  3018 
  3019 
  3020 *** ZF ***
  3021 
  3022 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  3023   only the theorems proved on ZF.ML;
  3024 
  3025 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  3026   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  3027   disjointness reasoning but breaking a few old proofs.
  3028 
  3029 * ZF/Update: new theory of function updates
  3030     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  3031   may also be iterated as in f(a:=b,c:=d,...);
  3032 
  3033 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  3034 
  3035 * calling (stac rew i) now fails if "rew" has no effect on the goal
  3036   [previously, this check worked only if the rewrite rule was unconditional]
  3037   Now rew can involve either definitions or equalities (either == or =).
  3038 
  3039 * case_tac provided for compatibility with HOL
  3040     (like the old excluded_middle_tac, but with subgoals swapped)
  3041 
  3042 
  3043 *** Internal programming interfaces ***
  3044 
  3045 * Pure: several new basic modules made available for general use, see
  3046 also src/Pure/README;
  3047 
  3048 * improved the theory data mechanism to support encapsulation (data
  3049 kind name replaced by private Object.kind, acting as authorization
  3050 key); new type-safe user interface via functor TheoryDataFun; generic
  3051 print_data function becomes basically useless;
  3052 
  3053 * removed global_names compatibility flag -- all theory declarations
  3054 are qualified by default;
  3055 
  3056 * module Pure/Syntax now offers quote / antiquote translation
  3057 functions (useful for Hoare logic etc. with implicit dependencies);
  3058 see HOL/ex/Antiquote for an example use;
  3059 
  3060 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  3061 cterm -> thm;
  3062 
  3063 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  3064 subgoal;
  3065 
  3066 * Display.print_goals function moved to Locale.print_goals;
  3067 
  3068 * standard print function for goals supports current_goals_markers
  3069 variable for marking begin of proof, end of proof, start of goal; the
  3070 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  3071 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  3072 for example;
  3073 
  3074 
  3075 
  3076 New in Isabelle98 (January 1998)
  3077 --------------------------------
  3078 
  3079 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3080 
  3081 * changed lexical syntax of terms / types: dots made part of long
  3082 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  3083 
  3084 * simpset (and claset) reference variable replaced by functions
  3085 simpset / simpset_ref;
  3086 
  3087 * no longer supports theory aliases (via merge) and non-trivial
  3088 implicit merge of thms' signatures;
  3089 
  3090 * most internal names of constants changed due to qualified names;
  3091 
  3092 * changed Pure/Sequence interface (see Pure/seq.ML);
  3093 
  3094 
  3095 *** General Changes ***
  3096 
  3097 * hierachically structured name spaces (for consts, types, axms, thms
  3098 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  3099 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  3100 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  3101 long_names for fully qualified output names; NOTE: ML programs
  3102 (special tactics, packages etc.) referring to internal names may have
  3103 to be adapted to cope with fully qualified names; in case of severe
  3104 backward campatibility problems try setting 'global_names' at compile
  3105 time to have enrything declared within a flat name space; one may also
  3106 fine tune name declarations in theories via the 'global' and 'local'
  3107 section;
  3108 
  3109 * reimplemented the implicit simpset and claset using the new anytype
  3110 data filed in signatures; references simpset:simpset ref etc. are
  3111 replaced by functions simpset:unit->simpset and
  3112 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  3113 to patch your ML files accordingly;
  3114 
  3115 * HTML output now includes theory graph data for display with Java
  3116 applet or isatool browser; data generated automatically via isatool
  3117 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  3118 
  3119 * defs may now be conditional; improved rewrite_goals_tac to handle
  3120 conditional equations;
  3121 
  3122 * defs now admits additional type arguments, using TYPE('a) syntax;
  3123 
  3124 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  3125 creates a new theory node; implicit merge of thms' signatures is
  3126 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  3127 transfer:theory->thm->thm in (rare) cases;
  3128 
  3129 * improved handling of draft signatures / theories; draft thms (and
  3130 ctyps, cterms) are automatically promoted to real ones;
  3131 
  3132 * slightly changed interfaces for oracles: admit many per theory, named
  3133 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  3134 
  3135 * print_goals: optional output of const types (set show_consts and
  3136 show_types);
  3137 
  3138 * improved output of warnings (###) and errors (***);
  3139 
  3140 * subgoal_tac displays a warning if the new subgoal has type variables;
  3141 
  3142 * removed old README and Makefiles;
  3143 
  3144 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  3145 
  3146 * removed obsolete init_pps and init_database;
  3147 
  3148 * deleted the obsolete tactical STATE, which was declared by
  3149     fun STATE tacfun st = tacfun st st;
  3150 
  3151 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  3152 (which abbreviates $HOME);
  3153 
  3154 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  3155 use isatool fixseq to adapt your ML programs (this works for fully
  3156 qualified references to the Sequence structure only!);
  3157 
  3158 * use_thy no longer requires writable current directory; it always
  3159 reloads .ML *and* .thy file, if either one is out of date;
  3160 
  3161 
  3162 *** Classical Reasoner ***
  3163 
  3164 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  3165 tactics that use classical reasoning to simplify a subgoal without
  3166 splitting it into several subgoals;
  3167 
  3168 * Safe_tac: like safe_tac but uses the default claset;
  3169 
  3170 
  3171 *** Simplifier ***
  3172 
  3173 * added simplification meta rules:
  3174     (asm_)(full_)simplify: simpset -> thm -> thm;
  3175 
  3176 * simplifier.ML no longer part of Pure -- has to be loaded by object
  3177 logics (again);
  3178 
  3179 * added prems argument to simplification procedures;
  3180 
  3181 * HOL, FOL, ZF: added infix function `addsplits':
  3182   instead of `<simpset> setloop (split_tac <thms>)'
  3183   you can simply write `<simpset> addsplits <thms>'
  3184 
  3185 
  3186 *** Syntax ***
  3187 
  3188 * TYPE('a) syntax for type reflection terms;
  3189 
  3190 * no longer handles consts with name "" -- declare as 'syntax' instead;
  3191 
  3192 * pretty printer: changed order of mixfix annotation preference (again!);
  3193 
  3194 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  3195 
  3196 
  3197 *** HOL ***
  3198 
  3199 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  3200   with `addloop' of the simplifier to faciliate case splitting in premises.
  3201 
  3202 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  3203 
  3204 * HOL/Auth: new protocol proofs including some for the Internet
  3205   protocol TLS;
  3206 
  3207 * HOL/Map: new theory of `maps' a la VDM;
  3208 
  3209 * HOL/simplifier: simplification procedures nat_cancel_sums for
  3210 cancelling out common nat summands from =, <, <= (in)equalities, or
  3211 differences; simplification procedures nat_cancel_factor for
  3212 cancelling common factor from =, <, <= (in)equalities over natural
  3213 sums; nat_cancel contains both kinds of procedures, it is installed by
  3214 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  3215 
  3216 * HOL/simplifier: terms of the form
  3217   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  3218   are rewritten to
  3219   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  3220   and those of the form
  3221   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  3222   are rewritten to
  3223   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  3224 
  3225 * HOL/datatype
  3226   Each datatype `t' now comes with a theorem `split_t_case' of the form
  3227 
  3228   P(t_case f1 ... fn x) =
  3229      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  3230         ...
  3231        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  3232      )
  3233 
  3234   and a theorem `split_t_case_asm' of the form
  3235 
  3236   P(t_case f1 ... fn x) =
  3237     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  3238         ...
  3239        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  3240      )
  3241   which can be added to a simpset via `addsplits'. The existing theorems
  3242   expand_list_case and expand_option_case have been renamed to
  3243   split_list_case and split_option_case.
  3244 
  3245 * HOL/Arithmetic:
  3246   - `pred n' is automatically converted to `n-1'.
  3247     Users are strongly encouraged not to use `pred' any longer,
  3248     because it will disappear altogether at some point.
  3249   - Users are strongly encouraged to write "0 < n" rather than
  3250     "n ~= 0". Theorems and proof tools have been modified towards this
  3251     `standard'.
  3252 
  3253 * HOL/Lists:
  3254   the function "set_of_list" has been renamed "set" (and its theorems too);
  3255   the function "nth" now takes its arguments in the reverse order and
  3256   has acquired the infix notation "!" as in "xs!n".
  3257 
  3258 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  3259 
  3260 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  3261   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  3262 
  3263 * HOL/record: extensible records with schematic structural subtyping
  3264 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  3265 still lacks various theorems and concrete record syntax;
  3266 
  3267 
  3268 *** HOLCF ***
  3269 
  3270 * removed "axioms" and "generated by" sections;
  3271 
  3272 * replaced "ops" section by extended "consts" section, which is capable of
  3273   handling the continuous function space "->" directly;
  3274 
  3275 * domain package:
  3276   . proves theorems immediately and stores them in the theory,
  3277   . creates hierachical name space,
  3278   . now uses normal mixfix annotations (instead of cinfix...),
  3279   . minor changes to some names and values (for consistency),
  3280   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  3281   . separator between mutual domain defs: changed "," to "and",
  3282   . improved handling of sort constraints;  now they have to
  3283     appear on the left-hand side of the equations only;
  3284 
  3285 * fixed LAM <x,y,zs>.b syntax;
  3286 
  3287 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  3288 adm (%x. P (t x)), where P is chainfinite and t continuous;
  3289 
  3290 
  3291 *** FOL and ZF ***
  3292 
  3293 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  3294   with `addloop' of the simplifier to faciliate case splitting in premises.
  3295 
  3296 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  3297 in HOL, they strip ALL and --> from proved theorems;
  3298 
  3299 
  3300 
  3301 New in Isabelle94-8 (May 1997)
  3302 ------------------------------
  3303 
  3304 *** General Changes ***
  3305 
  3306 * new utilities to build / run / maintain Isabelle etc. (in parts
  3307 still somewhat experimental); old Makefiles etc. still functional;
  3308 
  3309 * new 'Isabelle System Manual';
  3310 
  3311 * INSTALL text, together with ./configure and ./build scripts;
  3312 
  3313 * reimplemented type inference for greater efficiency, better error
  3314 messages and clean internal interface;
  3315 
  3316 * prlim command for dealing with lots of subgoals (an easier way of
  3317 setting goals_limit);
  3318 
  3319 
  3320 *** Syntax ***
  3321 
  3322 * supports alternative (named) syntax tables (parser and pretty
  3323 printer); internal interface is provided by add_modesyntax(_i);
  3324 
  3325 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  3326 be used in conjunction with the Isabelle symbol font; uses the
  3327 "symbols" syntax table;
  3328 
  3329 * added token_translation interface (may translate name tokens in
  3330 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  3331 the current print_mode); IMPORTANT: user print translation functions
  3332 are responsible for marking newly introduced bounds
  3333 (Syntax.mark_boundT);
  3334 
  3335 * token translations for modes "xterm" and "xterm_color" that display
  3336 names in bold, underline etc. or colors (which requires a color
  3337 version of xterm);
  3338 
  3339 * infixes may now be declared with names independent of their syntax;
  3340 
  3341 * added typed_print_translation (like print_translation, but may
  3342 access type of constant);
  3343 
  3344 
  3345 *** Classical Reasoner ***
  3346 
  3347 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  3348 some limitations.  Blast_tac...
  3349   + ignores addss, addbefore, addafter; this restriction is intrinsic
  3350   + ignores elimination rules that don't have the correct format
  3351         (the conclusion MUST be a formula variable)
  3352   + ignores types, which can make HOL proofs fail
  3353   + rules must not require higher-order unification, e.g. apply_type in ZF
  3354     [message "Function Var's argument not a bound variable" relates to this]
  3355   + its proof strategy is more general but can actually be slower
  3356 
  3357 * substitution with equality assumptions no longer permutes other
  3358 assumptions;
  3359 
  3360 * minor changes in semantics of addafter (now called addaltern); renamed
  3361 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  3362 (and access functions for it);
  3363 
  3364 * improved combination of classical reasoner and simplifier:
  3365   + functions for handling clasimpsets
  3366   + improvement of addss: now the simplifier is called _after_ the
  3367     safe steps.
  3368   + safe variant of addss called addSss: uses safe simplifications
  3369     _during_ the safe steps. It is more complete as it allows multiple
  3370     instantiations of unknowns (e.g. with slow_tac).
  3371 
  3372 *** Simplifier ***
  3373 
  3374 * added interface for simplification procedures (functions that
  3375 produce *proven* rewrite rules on the fly, depending on current
  3376 redex);
  3377 
  3378 * ordering on terms as parameter (used for ordered rewriting);
  3379 
  3380 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  3381 
  3382 * the solver is now split into a safe and an unsafe part.
  3383 This should be invisible for the normal user, except that the
  3384 functions setsolver and addsolver have been renamed to setSolver and
  3385 addSolver; added safe_asm_full_simp_tac;
  3386 
  3387 
  3388 *** HOL ***
  3389 
  3390 * a generic induction tactic `induct_tac' which works for all datatypes and
  3391 also for type `nat';
  3392 
  3393 * a generic case distinction tactic `exhaust_tac' which works for all
  3394 datatypes and also for type `nat';
  3395 
  3396 * each datatype comes with a function `size';
  3397 
  3398 * patterns in case expressions allow tuple patterns as arguments to
  3399 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  3400 
  3401 * primrec now also works with type nat;
  3402 
  3403 * recdef: a new declaration form, allows general recursive functions to be
  3404 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  3405 
  3406 * the constant for negation has been renamed from "not" to "Not" to
  3407 harmonize with FOL, ZF, LK, etc.;
  3408 
  3409 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  3410 infinite lists;
  3411 
  3412 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  3413 
  3414 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  3415 problems in commutative rings, using axiomatic type classes for + and *;
  3416 
  3417 * more examples in HOL/MiniML and HOL/Auth;
  3418 
  3419 * more default rewrite rules for quantifiers, union/intersection;
  3420 
  3421 * a new constant `arbitrary == @x.False';
  3422 
  3423 * HOLCF/IOA replaces old HOL/IOA;
  3424 
  3425 * HOLCF changes: derived all rules and arities
  3426   + axiomatic type classes instead of classes
  3427   + typedef instead of faking type definitions
  3428   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  3429   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  3430   + eliminated the types void, one, tr
  3431   + use unit lift and bool lift (with translations) instead of one and tr
  3432   + eliminated blift from Lift3.thy (use Def instead of blift)
  3433   all eliminated rules are derived as theorems --> no visible changes ;
  3434 
  3435 
  3436 *** ZF ***
  3437 
  3438 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  3439 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  3440 as ZF_cs addSIs [equalityI];
  3441 
  3442 
  3443 
  3444 New in Isabelle94-7 (November 96)
  3445 ---------------------------------
  3446 
  3447 * allowing negative levels (as offsets) in prlev and choplev;
  3448 
  3449 * super-linear speedup for large simplifications;
  3450 
  3451 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  3452 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  3453 FAIL); can suppress it using the command Delsimps (ex_simps @
  3454 all_simps); De Morgan laws are also now included, by default;
  3455 
  3456 * improved printing of ==>  :  ~:
  3457 
  3458 * new object-logic "Sequents" adds linear logic, while replacing LK
  3459 and Modal (thanks to Sara Kalvala);
  3460 
  3461 * HOL/Auth: correctness proofs for authentication protocols;
  3462 
  3463 * HOL: new auto_tac combines rewriting and classical reasoning (many
  3464 examples on HOL/Auth);
  3465 
  3466 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  3467 the rewriter and classical reasoner simultaneously;
  3468 
  3469 * function uresult no longer returns theorems in "standard" format;
  3470 regain previous version by: val uresult = standard o uresult;
  3471 
  3472 
  3473 
  3474 New in Isabelle94-6
  3475 -------------------
  3476 
  3477 * oracles -- these establish an interface between Isabelle and trusted
  3478 external reasoners, which may deliver results as theorems;
  3479 
  3480 * proof objects (in particular record all uses of oracles);
  3481 
  3482 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  3483 
  3484 * "constdefs" section in theory files;
  3485 
  3486 * "primrec" section (HOL) no longer requires names;
  3487 
  3488 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  3489 
  3490 
  3491 
  3492 New in Isabelle94-5
  3493 -------------------
  3494 
  3495 * reduced space requirements;
  3496 
  3497 * automatic HTML generation from theories;
  3498 
  3499 * theory files no longer require "..." (quotes) around most types;
  3500 
  3501 * new examples, including two proofs of the Church-Rosser theorem;
  3502 
  3503 * non-curried (1994) version of HOL is no longer distributed;
  3504 
  3505 
  3506 
  3507 New in Isabelle94-4
  3508 -------------------
  3509 
  3510 * greatly reduced space requirements;
  3511 
  3512 * theory files (.thy) no longer require \...\ escapes at line breaks;
  3513 
  3514 * searchable theorem database (see the section "Retrieving theorems" on
  3515 page 8 of the Reference Manual);
  3516 
  3517 * new examples, including Grabczewski's monumental case study of the
  3518 Axiom of Choice;
  3519 
  3520 * The previous version of HOL renamed to Old_HOL;
  3521 
  3522 * The new version of HOL (previously called CHOL) uses a curried syntax
  3523 for functions.  Application looks like f a b instead of f(a,b);
  3524 
  3525 * Mutually recursive inductive definitions finally work in HOL;
  3526 
  3527 * In ZF, pattern-matching on tuples is now available in all abstractions and
  3528 translates to the operator "split";
  3529 
  3530 
  3531 
  3532 New in Isabelle94-3
  3533 -------------------
  3534 
  3535 * new infix operator, addss, allowing the classical reasoner to
  3536 perform simplification at each step of its search.  Example:
  3537         fast_tac (cs addss ss)
  3538 
  3539 * a new logic, CHOL, the same as HOL, but with a curried syntax
  3540 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  3541 look like (a,b) instead of <a,b>;
  3542 
  3543 * PLEASE NOTE: CHOL will eventually replace HOL!
  3544 
  3545 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  3546 It translates to the operator "split".  A new theory of integers is available;
  3547 
  3548 * In ZF, integer numerals now denote two's-complement binary integers.
  3549 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  3550 
  3551 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  3552 of the Axiom of Choice;
  3553 
  3554 
  3555 
  3556 New in Isabelle94-2
  3557 -------------------
  3558 
  3559 * Significantly faster resolution;
  3560 
  3561 * the different sections in a .thy file can now be mixed and repeated
  3562 freely;
  3563 
  3564 * Database of theorems for FOL, HOL and ZF.  New
  3565 commands including qed, qed_goal and bind_thm store theorems in the database.
  3566 
  3567 * Simple database queries: return a named theorem (get_thm) or all theorems of
  3568 a given theory (thms_of), or find out what theory a theorem was proved in
  3569 (theory_of_thm);
  3570 
  3571 * Bugs fixed in the inductive definition and datatype packages;
  3572 
  3573 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  3574 and HOL_dup_cs obsolete;
  3575 
  3576 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  3577 have been removed;
  3578 
  3579 * Simpler definition of function space in ZF;
  3580 
  3581 * new results about cardinal and ordinal arithmetic in ZF;
  3582 
  3583 * 'subtype' facility in HOL for introducing new types as subsets of existing
  3584 types;
  3585 
  3586 
  3587 $Id$