NEWS
author huffman
Fri Sep 16 20:30:44 2005 +0200 (2005-09-16)
changeset 17439 a358da1a0218
parent 17436 4e603046e539
child 17442 c0f0b92c198c
permissions -rw-r--r--
add header
     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; HOL/ex/Hebrew.thy provides a simple example.
    50 
    51 * Improved efficiency of the Simplifier and, to a lesser degree, the
    52 Classical Reasoner.  Typical big applications run around 2 times
    53 faster.
    54 
    55 
    56 *** Document preparation ***
    57 
    58 * Commands 'display_drafts' and 'print_drafts' perform simple output
    59 of raw sources.  Only those symbols that do not require additional
    60 LaTeX packages (depending on comments in isabellesym.sty) are
    61 displayed properly, everything else is left verbatim.  isatool display
    62 and isatool print are used as front ends (these are subject to the
    63 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
    64 
    65 * Command tags control specific markup of certain regions of text,
    66 notably folding and hiding.  Predefined tags include "theory" (for
    67 theory begin and end), "proof" for proof commands, and "ML" for
    68 commands involving ML code; the additional tags "visible" and
    69 "invisible" are unused by default.  Users may give explicit tag
    70 specifications in the text, e.g. ''by %invisible (auto)''.  The
    71 interpretation of tags is determined by the LaTeX job during document
    72 preparation: see option -V of isatool usedir, or options -n and -t of
    73 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
    74 \isadroptag.
    75 
    76 Several document versions may be produced at the same time via isatool
    77 usedir (the generated index.html will link all of them).  Typical
    78 specifications include ''-V document=theory,proof,ML'' to present
    79 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
    80 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
    81 these parts without any formal replacement text.  The Isabelle site
    82 default settings produce ''document'' and ''outline'' versions as
    83 specified above.
    84 
    85 * Several new antiquotations:
    86 
    87   @{term_type term} prints a term with its type annotated;
    88 
    89   @{typeof term} prints the type of a term;
    90 
    91   @{const const} is the same as @{term const}, but checks that the
    92   argument is a known logical constant;
    93 
    94   @{term_style style term} and @{thm_style style thm} print a term or
    95   theorem applying a "style" to it
    96 
    97   @{ML text}
    98 
    99 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
   100 definitions, equations, inequations etc., 'concl' printing only the
   101 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
   102 to print the specified premise.  TermStyle.add_style provides an ML
   103 interface for introducing further styles.  See also the "LaTeX Sugar"
   104 document practical applications.  The ML antiquotation prints
   105 type-checked ML expressions verbatim.
   106 
   107 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
   108 and 'text' support optional locale specification '(in loc)', which
   109 specifies the default context for interpreting antiquotations.  For
   110 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
   111 
   112 * Option 'locale=NAME' of antiquotations specifies an alternative
   113 context interpreting the subsequent argument.  For example: @{thm
   114 [locale=lattice] inf_assoc}.
   115 
   116 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
   117 a proof context.
   118 
   119 * Proper output of antiquotations for theory commands involving a
   120 proof context (such as 'locale' or 'theorem (in loc) ...').
   121 
   122 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
   123 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
   124 
   125 * isatool usedir: new option -C (default true) controls whether option
   126 -D should include a copy of the original document directory; -C false
   127 prevents unwanted effects such as copying of administrative CVS data.
   128 
   129 
   130 *** Pure ***
   131 
   132 * Considerably improved version of 'constdefs' command.  Now performs
   133 automatic type-inference of declared constants; additional support for
   134 local structure declarations (cf. locales and HOL records), see also
   135 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
   136 sequential dependencies of definitions within a single 'constdefs'
   137 section; moreover, the declared name needs to be an identifier.  If
   138 all fails, consider to fall back on 'consts' and 'defs' separately.
   139 
   140 * Improved indexed syntax and implicit structures.  First of all,
   141 indexed syntax provides a notational device for subscripted
   142 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
   143 expressions.  Secondly, in a local context with structure
   144 declarations, number indexes \<^sub>n or the empty index (default
   145 number 1) refer to a certain fixed variable implicitly; option
   146 show_structs controls printing of implicit structures.  Typical
   147 applications of these concepts involve record types and locales.
   148 
   149 * New command 'no_syntax' removes grammar declarations (and
   150 translations) resulting from the given syntax specification, which is
   151 interpreted in the same manner as for the 'syntax' command.
   152 
   153 * 'Advanced' translation functions (parse_translation etc.) may depend
   154 on the signature of the theory context being presently used for
   155 parsing/printing, see also isar-ref manual.
   156 
   157 * Improved 'oracle' command provides a type-safe interface to turn an
   158 ML expression of type theory -> T -> term into a primitive rule of
   159 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
   160 is already included here); see also FOL/ex/IffExample.thy;
   161 INCOMPATIBILITY.
   162 
   163 * axclass: name space prefix for class "c" is now "c_class" (was "c"
   164 before); "cI" is no longer bound, use "c.intro" instead.
   165 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
   166 axclasses vs. locales.
   167 
   168 * Improved internal renaming of symbolic identifiers -- attach primes
   169 instead of base 26 numbers.
   170 
   171 * New flag show_question_marks controls printing of leading question
   172 marks in schematic variable names.
   173 
   174 * In schematic variable names, *any* symbol following \<^isub> or
   175 \<^isup> is now treated as part of the base name.  For example, the
   176 following works without printing of awkward ".0" indexes:
   177 
   178   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
   179     by simp
   180 
   181 * Inner syntax includes (*(*nested*) comments*).
   182 
   183 * Pretty pinter now supports unbreakable blocks, specified in mixfix
   184 annotations as "(00...)".
   185 
   186 * Clear separation of logical types and nonterminals, where the latter
   187 may only occur in 'syntax' specifications or type abbreviations.
   188 Before that distinction was only partially implemented via type class
   189 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
   190 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
   191 exotic syntax specifications may require further adaption
   192 (e.g. Cube/Base.thy).
   193 
   194 * Removed obsolete type class "logic", use the top sort {} instead.
   195 Note that non-logical types should be declared as 'nonterminals'
   196 rather than 'types'.  INCOMPATIBILITY for new object-logic
   197 specifications.
   198 
   199 * Attributes 'induct' and 'cases': type or set names may now be
   200 locally fixed variables as well.
   201 
   202 * Simplifier: can now control the depth to which conditional rewriting
   203 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
   204 Limit.
   205 
   206 * Simplifier: simplification procedures may now take the current
   207 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
   208 interface), which is very useful for calling the Simplifier
   209 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
   210 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
   211 low-level mk_simproc no longer applies Logic.varify internally, to
   212 allow for use in a context of fixed variables.
   213 
   214 * thin_tac now works even if the assumption being deleted contains !!
   215 or ==>.  More generally, erule now works even if the major premise of
   216 the elimination rule contains !! or ==>.
   217 
   218 * Reorganized bootstrapping of the Pure theories; CPure is now derived
   219 from Pure, which contains all common declarations already.  Both
   220 theories are defined via plain Isabelle/Isar .thy files.
   221 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
   222 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
   223 use isatool fixcpure to adapt your theory and ML sources.
   224 
   225 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
   226 selections of theorems in named facts via index ranges.
   227 
   228 * 'print_theorems': in theory mode, really print the difference
   229 wrt. the last state (works for interactive theory development only),
   230 in proof mode print all local facts (cf. 'print_facts');
   231 
   232 * 'hide': option '(open)' hides only base names.
   233 
   234 * More efficient treatment of intermediate checkpoints in interactive
   235 theory development.
   236 
   237 
   238 *** Locales ***
   239 
   240 * New commands for the interpretation of locale expressions in
   241 theories (1), locales (2) and proof contexts (3).  These generate
   242 proof obligations from the expression specification.  After the
   243 obligations have been discharged, theorems of the expression are added
   244 to the theory, target locale or proof context.  The synopsis of the
   245 commands is a follows:
   246 
   247   (1) interpretation expr inst
   248   (2) interpretation target < expr
   249   (3) interpret expr inst
   250 
   251 Interpretation in theories and proof contexts require a parameter
   252 instantiation of terms from the current context.  This is applied to
   253 specifications and theorems of the interpreted expression.
   254 Interpretation in locales only permits parameter renaming through the
   255 locale expression.  Interpretation is smart in that interpretations
   256 that are active already do not occur in proof obligations, neither are
   257 instantiated theorems stored in duplicate.  Use 'print_interps' to
   258 inspect active interpretations of a particular locale.  For details,
   259 see the Isar Reference manual.  Examples can be found in
   260 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
   261 
   262 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
   263 'interpret' instead.
   264 
   265 * New context element 'constrains' for adding type constraints to
   266 parameters.
   267 
   268 * Context expressions: renaming of parameters with syntax
   269 redeclaration.
   270 
   271 * Locale declaration: 'includes' disallowed.
   272 
   273 * Proper static binding of attribute syntax -- i.e. types / terms /
   274 facts mentioned as arguments are always those of the locale definition
   275 context, independently of the context of later invocations.  Moreover,
   276 locale operations (renaming and type / term instantiation) are applied
   277 to attribute arguments as expected.
   278 
   279 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
   280 actual attributes; rare situations may require Attrib.attribute to
   281 embed those attributes into Attrib.src that lack concrete syntax.
   282 Attribute implementations need to cooperate properly with the static
   283 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
   284 Attrib.XXX_thm etc. already do the right thing without further
   285 intervention.  Only unusual applications -- such as "where" or "of"
   286 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
   287 on the context and the facts involved -- may have to assign parsed
   288 values to argument tokens explicitly.
   289 
   290 * Changed parameter management in theorem generation for long goal
   291 statements with 'includes'.  INCOMPATIBILITY: produces a different
   292 theorem statement in rare situations.
   293 
   294 * Locale inspection command 'print_locale' omits notes elements.  Use
   295 'print_locale!' to have them included in the output.
   296 
   297 
   298 *** Provers ***
   299 
   300 * Provers/hypsubst.ML: improved version of the subst method, for
   301 single-step rewriting: it now works in bound variable contexts. New is
   302 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
   303 rewrite a different subterm than the original subst method, which is
   304 still available as 'simplesubst'.
   305 
   306 * Provers/quasi.ML: new transitivity reasoners for transitivity only
   307 and quasi orders.
   308 
   309 * Provers/trancl.ML: new transitivity reasoner for transitive and
   310 reflexive-transitive closure of relations.
   311 
   312 * Provers/blast.ML: new reference depth_limit to make blast's depth
   313 limit (previously hard-coded with a value of 20) user-definable.
   314 
   315 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
   316 is peformed already.  Object-logics merely need to finish their
   317 initial simpset configuration as before.  INCOMPATIBILITY.
   318 
   319 
   320 *** HOL ***
   321 
   322 * Symbolic syntax of Hilbert Choice Operator is now as follows:
   323 
   324   syntax (epsilon)
   325     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
   326 
   327 The symbol \<some> is displayed as the alternative epsilon of LaTeX
   328 and x-symbol; use option '-m epsilon' to get it actually printed.
   329 Moreover, the mathematically important symbolic identifier \<epsilon>
   330 becomes available as variable, constant etc.  INCOMPATIBILITY,
   331 
   332 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
   333 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
   334 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
   335 support corresponding Isar calculations.
   336 
   337 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
   338 instead of ":".
   339 
   340 * theory SetInterval: changed the syntax for open intervals:
   341 
   342   Old       New
   343   {..n(}    {..<n}
   344   {)n..}    {n<..}
   345   {m..n(}   {m..<n}
   346   {)m..n}   {m<..n}
   347   {)m..n(}  {m<..<n}
   348 
   349 The old syntax is still supported but will disappear in the next
   350 release.  For conversion use the following Emacs search and replace
   351 patterns (these are not perfect but work quite well):
   352 
   353   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
   354   \.\.\([^(}]*\)(}  ->  \.\.<\1}
   355 
   356 * Method comm_ring for proving equalities in commutative rings.
   357 
   358 * Theory Finite_Set: changed the syntax for 'setsum', summation over
   359 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
   360 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
   361 be a tuple pattern.
   362 
   363 Some new syntax forms are available:
   364 
   365   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
   366   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
   367   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
   368   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
   369 
   370 The latter form "\<Sum>x < k. e" used to be based on a separate
   371 function "Summation", which has been discontinued.
   372 
   373 * theory Finite_Set: in structured induction proofs, the insert case
   374 is now 'case (insert x F)' instead of the old counterintuitive 'case
   375 (insert F x)'.
   376 
   377 * The 'refute' command has been extended to support a much larger
   378 fragment of HOL, including axiomatic type classes, constdefs and
   379 typedefs, inductive datatypes and recursion.
   380 
   381 * Datatype induction via method 'induct' now preserves the name of the
   382 induction variable. For example, when proving P(xs::'a list) by
   383 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
   384 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
   385 in unstructured proof scripts.
   386 
   387 * Reworked implementation of records.  Improved scalability for
   388 records with many fields, avoiding performance problems for type
   389 inference. Records are no longer composed of nested field types, but
   390 of nested extension types. Therefore the record type only grows linear
   391 in the number of extensions and not in the number of fields.  The
   392 top-level (users) view on records is preserved.  Potential
   393 INCOMPATIBILITY only in strange cases, where the theory depends on the
   394 old record representation. The type generated for a record is called
   395 <record_name>_ext_type.
   396 
   397 Flag record_quick_and_dirty_sensitive can be enabled to skip the
   398 proofs triggered by a record definition or a simproc (if
   399 quick_and_dirty is enabled).  Definitions of large records can take
   400 quite long.
   401 
   402 New simproc record_upd_simproc for simplification of multiple record
   403 updates enabled by default.  Moreover, trivial updates are also
   404 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
   405 occasionally, since simplification is more powerful by default.
   406 
   407 * typedef: proper support for polymorphic sets, which contain extra
   408 type-variables in the term.
   409 
   410 * Simplifier: automatically reasons about transitivity chains
   411 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
   412 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
   413 old proofs break occasionally as simplification may now solve more
   414 goals than previously.
   415 
   416 * Simplifier: converts x <= y into x = y if assumption y <= x is
   417 present.  Works for all partial orders (class "order"), in particular
   418 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
   419 just like y <= x.
   420 
   421 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
   422 bound variable or a constant then the let is unfolded.  Otherwise
   423 first a is simplified to b, and then f b is simplified to g. If
   424 possible we abstract b from g arriving at "let x = b in h x",
   425 otherwise we unfold the let and arrive at g.  The simproc can be
   426 enabled/disabled by the reference use_let_simproc.  Potential
   427 INCOMPATIBILITY since simplification is more powerful by default.
   428 
   429 * Classical reasoning: the meson method now accepts theorems as arguments.
   430 
   431 * Theory OrderedGroup and Ring_and_Field: various additions and
   432 improvements to faciliate calculations involving equalities and
   433 inequalities.
   434 
   435 The following theorems have been eliminated or modified
   436 (INCOMPATIBILITY):
   437 
   438   abs_eq             now named abs_of_nonneg
   439   abs_of_ge_0        now named abs_of_nonneg
   440   abs_minus_eq       now named abs_of_nonpos
   441   imp_abs_id         now named abs_of_nonneg
   442   imp_abs_neg_id     now named abs_of_nonpos
   443   mult_pos           now named mult_pos_pos
   444   mult_pos_le        now named mult_nonneg_nonneg
   445   mult_pos_neg_le    now named mult_nonneg_nonpos
   446   mult_pos_neg2_le   now named mult_nonneg_nonpos2
   447   mult_neg           now named mult_neg_neg
   448   mult_neg_le        now named mult_nonpos_nonpos
   449 
   450 * Theory Parity: added rules for simplifying exponents.
   451 
   452 * Theory List:
   453 
   454 The following theorems have been eliminated or modified
   455 (INCOMPATIBILITY):
   456 
   457   list_all_Nil       now named list_all.simps(1)
   458   list_all_Cons      now named list_all.simps(2)
   459   list_all_conv      now named list_all_iff
   460   set_mem_eq         now named mem_iff
   461 
   462 * Theories SetsAndFunctions and BigO (see HOL/Library) support
   463 asymptotic "big O" calculations.  See the notes in BigO.thy.
   464 
   465 
   466 *** HOL-Complex ***
   467 
   468 * Theory RealDef: better support for embedding natural numbers and
   469 integers in the reals.
   470 
   471 The following theorems have been eliminated or modified
   472 (INCOMPATIBILITY):
   473 
   474   exp_ge_add_one_self  now requires no hypotheses
   475   real_of_int_add      reversed direction of equality (use [symmetric])
   476   real_of_int_minus    reversed direction of equality (use [symmetric])
   477   real_of_int_diff     reversed direction of equality (use [symmetric])
   478   real_of_int_mult     reversed direction of equality (use [symmetric])
   479 
   480 * Theory RComplete: expanded support for floor and ceiling functions.
   481 
   482 * Theory Ln is new, with properties of the natural logarithm
   483 
   484 * Hyperreal: There is a new type constructor "star" for making
   485 nonstandard types.  The old type names are now type synonyms:
   486 
   487   hypreal = real star
   488   hypnat = nat star
   489   hcomplex = complex star
   490 
   491 * Hyperreal: Many groups of similarly-defined constants have been
   492 replaced by polymorphic versions:
   493 
   494   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
   495 
   496   starset      <-- starsetNat, starsetC
   497   *s*          <-- *sNat*, *sc*
   498   starset_n    <-- starsetNat_n, starsetC_n
   499   *sn*         <-- *sNatn*, *scn*
   500   InternalSets <-- InternalNatSets, InternalCSets
   501 
   502   starfun      <-- starfunNat, starfunNat2, starfunC, starfunRC, starfunCR
   503   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
   504   starfun_n    <-- starfunNat_n, starfunNat2_n, starfunC_n, starfunRC_n, starfunCR_n
   505   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
   506   InternalFuns <-- InternalNatFuns, InternalNatFuns2, InternalCFuns, InternalRCFuns, InternalCRFuns
   507 
   508 * Hyperreal: Many type-specific theorems have been removed in favor of
   509 theorems specific to various axiomatic type classes:
   510 
   511   add_commute <-- hypreal_add_commute, hypnat_add_commute, hcomplex_add_commute
   512   add_assoc   <-- hypreal_add_assoc, hypnat_add_assoc, hcomplex_add_assoc
   513   OrderedGroup.add_0 <-- hypreal_add_zero_left, hypnat_add_zero_left, hcomplex_add_zero_left
   514   OrderedGroup.add_0_right <-- hypreal_add_zero_right, hcomplex_add_zero_right
   515   right_minus <-- hypreal_add_minus
   516   left_minus <-- hypreal_add_minus_left, hcomplex_add_minus_left
   517   mult_commute <-- hypreal_mult_commute, hypnat_mult_commute, hcomplex_mult_commute
   518   mult_assoc <-- hypreal_mult_assoc, hypnat_mult_assoc, hcomplex_mult_assoc
   519   mult_1_left <-- hypreal_mult_1, hypnat_mult_1, hcomplex_mult_one_left
   520   mult_1_right <-- hcomplex_mult_one_right
   521   mult_zero_left <-- hcomplex_mult_zero_left
   522   left_distrib <-- hypreal_add_mult_distrib, hypnat_add_mult_distrib, hcomplex_add_mult_distrib
   523   right_distrib <-- hypnat_add_mult_distrib2
   524   zero_neq_one <-- hypreal_zero_not_eq_one, hypnat_zero_not_eq_one, hcomplex_zero_not_eq_one
   525   right_inverse <-- hypreal_mult_inverse
   526   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
   527   order_refl <-- hypreal_le_refl, hypnat_le_refl
   528   order_trans <-- hypreal_le_trans, hypnat_le_trans
   529   order_antisym <-- hypreal_le_anti_sym, hypnat_le_anti_sym
   530   order_less_le <-- hypreal_less_le, hypnat_less_le
   531   linorder_linear <-- hypreal_le_linear, hypnat_le_linear
   532   add_left_mono <-- hypreal_add_left_mono, hypnat_add_left_mono
   533   mult_strict_left_mono <-- hypreal_mult_less_mono2, hypnat_mult_less_mono2
   534   add_nonneg_nonneg <-- hypreal_le_add_order
   535 
   536 * Hyperreal: Separate theorems having to do with type-specific
   537 versions of constants have been merged into theorems that apply to the
   538 new polymorphic constants:
   539 
   540   STAR_UNIV_set <-- STAR_real_set, NatStar_real_set, STARC_complex_set
   541   STAR_empty_set <-- NatStar_empty_set, STARC_empty_set
   542   STAR_Un <-- NatStar_Un, STARC_Un
   543   STAR_Int <-- NatStar_Int, STARC_Int
   544   STAR_Compl <-- NatStar_Compl, STARC_Compl
   545   STAR_subset <-- NatStar_subset, STARC_subset
   546   STAR_mem <-- NatStar_mem, STARC_mem
   547   STAR_mem_Compl <-- STARC_mem_Compl
   548   STAR_diff <-- STARC_diff
   549   STAR_star_of_image_subset <-- STAR_hypreal_of_real_image_subset, NatStar_hypreal_of_real_image_subset, STARC_hcomplex_of_complex_image_subset
   550   starset_n_Un <-- starsetNat_n_Un, starsetC_n_Un
   551   starset_n_Int <-- starsetNat_n_Int, starsetC_n_Int
   552   starset_n_Compl <-- starsetNat_n_Compl, starsetC_n_Compl
   553   starset_n_diff <-- starsetNat_n_diff, starsetC_n_diff
   554   InternalSets_Un <-- InternalNatSets_Un, InternalCSets_Un
   555   InternalSets_Int <-- InternalNatSets_Int, InternalCSets_Int
   556   InternalSets_Compl <-- InternalNatSets_Compl, InternalCSets_Compl
   557   InternalSets_diff <-- InternalNatSets_diff, InternalCSets_diff
   558   InternalSets_UNIV_diff <-- InternalNatSets_UNIV_diff, InternalCSets_UNIV_diff
   559   InternalSets_starset_n <-- InternalNatSets_starsetNat_n, InternalCSets_starsetC_n
   560   starset_starset_n_eq <-- starsetNat_starsetNat_n_eq, starsetC_starsetC_n_eq
   561   starset_n_starset <-- starsetNat_n_starsetNat, starsetC_n_starsetC
   562   starfun_n_starfun <-- starfunNat_n_starfunNat, starfunNat2_n_starfunNat2, starfunC_n_starfunC, starfunRC_n_starfunRC, starfunCR_n_starfunCR
   563   starfun <-- starfunNat, starfunNat2, starfunC, starfunRC, starfunCR
   564   starfun_mult <-- starfunNat_mult, starfunNat2_mult, starfunC_mult, starfunRC_mult, starfunCR_mult
   565   starfun_add <-- starfunNat_add, starfunNat2_add, starfunC_add, starfunRC_add, starfunCR_add
   566   starfun_minus <-- starfunNat_minus, starfunNat2_minus, starfunC_minus, starfunRC_minus, starfunCR_minus
   567   starfun_diff <-- starfunC_diff, starfunRC_diff, starfunCR_diff
   568   starfun_o <-- starfunNatNat2_o, starfunNat2_o, starfun_stafunNat_o, starfunC_o, starfunC_starfunRC_o, starfun_starfunCR_o
   569   starfun_o2 <-- starfunNatNat2_o2, starfun_stafunNat_o2, starfunC_o2, starfunC_starfunRC_o2, starfun_starfunCR_o2
   570   starfun_const_fun <-- starfunNat_const_fun, starfunNat2_const_fun, starfunC_const_fun, starfunRC_const_fun, starfunCR_const_fun
   571   starfun_inverse <-- starfunNat_inverse, starfunC_inverse, starfunRC_inverse, starfunCR_inverse
   572   starfun_eq <-- starfunNat_eq, starfunNat2_eq, starfunC_eq, starfunRC_eq, starfunCR_eq
   573   starfun_eq_iff <-- starfunC_eq_iff, starfunRC_eq_iff, starfunCR_eq_iff
   574   starfun_Id <-- starfunC_Id
   575   starfun_approx <-- starfunNat_approx, starfunCR_approx
   576   starfun_capprox <-- starfunC_capprox, starfunRC_capprox
   577   starfun_abs <-- starfunNat_rabs
   578   starfun_lambda_cancel <-- starfunC_lambda_cancel, starfunCR_lambda_cancel, starfunRC_lambda_cancel
   579   starfun_lambda_cancel2 <-- starfunC_lambda_cancel2, starfunCR_lambda_cancel2, starfunRC_lambda_cancel2
   580   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
   581   starfun_mult_CFinite_capprox <-- starfunC_mult_CFinite_capprox, starfunRC_mult_CFinite_capprox
   582   starfun_add_capprox <-- starfunC_add_capprox, starfunRC_add_capprox
   583   starfun_add_approx <-- starfunCR_add_approx
   584   starfun_inverse_inverse <-- starfunC_inverse_inverse
   585   starfun_divide <-- starfunC_divide, starfunCR_divide, starfunRC_divide
   586   starfun_n_congruent <-- starfunNat_n_congruent, starfunC_n_congruent
   587   starfun_n <-- starfunNat_n, starfunC_n
   588   starfun_n_mult <-- starfunNat_n_mult, starfunC_n_mult
   589   starfun_n_add <-- starfunNat_n_add, starfunC_n_add
   590   starfun_n_add_minus <-- starfunNat_n_add_minus
   591   starfun_n_const_fun <-- starfunNat_n_const_fun, starfunC_n_const_fun
   592   starfun_n_minus <-- starfunNat_n_minus, starfunC_n_minus
   593   starfun_n_eq <-- starfunNat_n_eq, starfunC_n_eq
   594 
   595   star_n_add <-- hypreal_add, hypnat_add, hcomplex_add
   596   star_n_minus <-- hypreal_minus, hcomplex_minus
   597   star_n_diff <-- hypreal_diff, hcomplex_diff
   598   star_n_mult <-- hypreal_mult, hcomplex_mult
   599   star_n_inverse <-- hypreal_inverse, hcomplex_inverse
   600   star_n_le <-- hypreal_le, hypnat_le
   601   star_n_less <-- hypreal_less, hypnat_less
   602   star_n_zero_num <-- hypreal_zero_num, hypnat_zero_num, hcomplex_zero_num
   603   star_n_one_num <-- hypreal_one_num, hypnat_one_num, hcomplex_one_num
   604   star_n_abs <-- hypreal_hrabs
   605   star_n_divide <-- hcomplex_divide
   606 
   607   star_of_add <-- hypreal_of_real_add, hcomplex_of_complex_add
   608   star_of_minus <-- hypreal_of_real_minus, hcomplex_of_complex_minus
   609   star_of_diff <-- hypreal_of_real_diff
   610   star_of_mult <-- hypreal_of_real_mult, hcomplex_of_complex_mult
   611   star_of_one <-- hypreal_of_real_one, hcomplex_of_complex_one
   612   star_of_zero <-- hypreal_of_real_zero, hcomplex_of_complex_zero
   613   star_of_le <-- hypreal_of_real_le_iff
   614   star_of_less <-- hypreal_of_real_less_iff
   615   star_of_eq <-- hypreal_of_real_eq_iff, hcomplex_of_complex_eq_iff
   616   star_of_inverse <-- hypreal_of_real_inverse, hcomplex_of_complex_inverse
   617   star_of_divide <-- hypreal_of_real_divide, hcomplex_of_complex_divide
   618   star_of_of_nat <-- hypreal_of_real_of_nat, hcomplex_of_complex_of_nat
   619   star_of_of_int <-- hypreal_of_real_of_int, hcomplex_of_complex_of_int
   620   star_of_number_of <-- hypreal_number_of, hcomplex_number_of
   621   star_of_number_less <-- number_of_less_hypreal_of_real_iff
   622   star_of_number_le <-- number_of_le_hypreal_of_real_iff
   623   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
   624   star_of_less_number <-- hypreal_of_real_less_number_of_iff
   625   star_of_le_number <-- hypreal_of_real_le_number_of_iff
   626   star_of_power <-- hypreal_of_real_power
   627   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
   628 
   629 
   630 *** HOLCF ***
   631 
   632 * HOLCF: discontinued special version of 'constdefs' (which used to
   633 support continuous functions) in favor of the general Pure one with
   634 full type-inference.
   635 
   636 
   637 *** ZF ***
   638 
   639 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
   640 including the First Isomorphism Theorem (on quotienting by the kernel
   641 of a homomorphism).
   642 
   643 * ZF/Simplifier: install second copy of type solver that actually
   644 makes use of TC rules declared to Isar proof contexts (or locales);
   645 the old version is still required for ML proof scripts.
   646 
   647 
   648 *** ML ***
   649 
   650 * Pure/library.ML no longer defines its own option datatype, but uses
   651 that of the SML basis, which has constructors NONE and SOME instead of
   652 None and Some, as well as exception Option.Option instead of OPTION.
   653 The functions the, if_none, is_some, is_none have been adapted
   654 accordingly, while Option.map replaces apsome.
   655 
   656 * Pure/library.ML: the exception LIST has been given up in favour of
   657 the standard exceptions Empty and Subscript, as well as
   658 Library.UnequalLengths.  Function like Library.hd and Library.tl are
   659 superceded by the standard hd and tl functions etc.
   660 
   661 A number of basic list functions are no longer exported to the ML
   662 toplevel, as they are variants of predefined functions.  The following
   663 suggests how one can translate existing code:
   664 
   665     rev_append xs ys = List.revAppend (xs, ys)
   666     nth_elem (i, xs) = List.nth (xs, i)
   667     last_elem xs = List.last xs
   668     flat xss = List.concat xss
   669     seq fs = List.app fs
   670     partition P xs = List.partition P xs
   671     mapfilter f xs = List.mapPartial f xs
   672 
   673 * Pure/library.ML: several combinators for linear functional
   674 transformations, notably reverse application and composition:
   675 
   676   x |> f                f #> g
   677   (x, y) |-> f          f #-> g
   678 
   679 * Pure/library.ML: natural list combinators fold, fold_rev, and
   680 fold_map support linear functional transformations and nesting.  For
   681 example:
   682 
   683   fold f [x1, ..., xN] y =
   684     y |> f x1 |> ... |> f xN
   685 
   686   (fold o fold) f [xs1, ..., xsN] y =
   687     y |> fold f xs1 |> ... |> fold f xsN
   688 
   689   fold f [x1, ..., xN] =
   690     f x1 #> ... #> f xN
   691 
   692   (fold o fold) f [xs1, ..., xsN] =
   693     fold f xs1 #> ... #> fold f xsN
   694 
   695 * Pure/library.ML: the following selectors on type 'a option are
   696 available:
   697 
   698   the:               'a option -> 'a  (*partial*)
   699   these:             'a option -> 'a  where 'a = 'b list
   700   the_default: 'a -> 'a option -> 'a
   701   the_list:          'a option -> 'a list
   702 
   703 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
   704 basic operations for association lists, following natural argument
   705 order.  The old functions may be expressed as follows:
   706 
   707   assoc = uncurry (AList.lookup (op =))
   708   assocs = these oo AList.lookup (op =)
   709   overwrite = uncurry (AList.update (op =)) o swap
   710 
   711 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
   712 basic operations for association lists, following natural argument
   713 order; moreover the explicit equality predicate passed here avoids
   714 potentially expensive polymorphic runtime equality checks.
   715 
   716 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
   717 provides a reasonably efficient light-weight implementation of sets as
   718 lists.
   719 
   720 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
   721 few new operations; existing lookup and update are now curried to
   722 follow natural argument order (for use with fold etc.);
   723 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
   724 
   725 * Pure/General: output via the Isabelle channels of
   726 writeln/warning/error etc. is now passed through Output.output, with a
   727 hook for arbitrary transformations depending on the print_mode
   728 (cf. Output.add_mode -- the first active mode that provides a output
   729 function wins).  Already formatted output may be embedded into further
   730 text via Output.raw; the result of Pretty.string_of/str_of and derived
   731 functions (string_of_term/cterm/thm etc.) is already marked raw to
   732 accommodate easy composition of diagnostic messages etc.  Programmers
   733 rarely need to care about Output.output or Output.raw at all, with
   734 some notable exceptions: Output.output is required when bypassing the
   735 standard channels (writeln etc.), or in token translations to produce
   736 properly formatted results; Output.raw is required when capturing
   737 already output material that will eventually be presented to the user
   738 a second time.  For the default print mode, both Output.output and
   739 Output.raw have no effect.
   740 
   741 * Pure/General: Output.time_accumulator NAME creates an operator ('a
   742 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
   743 cumulative results are displayed at the end of a batch session.
   744 
   745 * Pure/General: File.sysify_path and File.quote_sysify path have been
   746 replaced by File.platform_path and File.shell_path (with appropriate
   747 hooks).  This provides a clean interface for unusual systems where the
   748 internal and external process view of file names are different.
   749 
   750 * Pure: more efficient orders for basic syntactic entities: added
   751 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
   752 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
   753 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
   754 orders now -- potential INCOMPATIBILITY for code that depends on a
   755 particular order for Symtab.keys, Symtab.dest, etc. (consider using
   756 Library.sort_strings on result).
   757 
   758 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
   759 fold_types traverse types/terms from left to right, observing natural
   760 argument order.  Supercedes previous foldl_XXX versions, add_frees,
   761 add_vars etc. have been adapted as well: INCOMPATIBILITY.
   762 
   763 * Pure: name spaces have been refined, with significant changes of the
   764 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
   765 to extern(_table).  The plain name entry path is superceded by a
   766 general 'naming' context, which also includes the 'policy' to produce
   767 a fully qualified name and external accesses of a fully qualified
   768 name; NameSpace.extend is superceded by context dependent
   769 Sign.declare_name.  Several theory and proof context operations modify
   770 the naming context.  Especially note Theory.restore_naming and
   771 ProofContext.restore_naming to get back to a sane state; note that
   772 Theory.add_path is no longer sufficient to recover from
   773 Theory.absolute_path in particular.
   774 
   775 * Pure: new flags short_names (default false) and unique_names
   776 (default true) for controlling output of qualified names.  If
   777 short_names is set, names are printed unqualified.  If unique_names is
   778 reset, the name prefix is reduced to the minimum required to achieve
   779 the original result when interning again, even if there is an overlap
   780 with earlier declarations.
   781 
   782 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
   783 now 'extend', and 'merge' gets an additional Pretty.pp argument
   784 (useful for printing error messages).  INCOMPATIBILITY.
   785 
   786 * Pure: major reorganization of the theory context.  Type Sign.sg and
   787 Theory.theory are now identified, referring to the universal
   788 Context.theory (see Pure/context.ML).  Actual signature and theory
   789 content is managed as theory data.  The old code and interfaces were
   790 spread over many files and structures; the new arrangement introduces
   791 considerable INCOMPATIBILITY to gain more clarity:
   792 
   793   Context -- theory management operations (name, identity, inclusion,
   794     parents, ancestors, merge, etc.), plus generic theory data;
   795 
   796   Sign -- logical signature and syntax operations (declaring consts,
   797     types, etc.), plus certify/read for common entities;
   798 
   799   Theory -- logical theory operations (stating axioms, definitions,
   800     oracles), plus a copy of logical signature operations (consts,
   801     types, etc.); also a few basic management operations (Theory.copy,
   802     Theory.merge, etc.)
   803 
   804 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
   805 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
   806 for convenience -- they merely return the theory.
   807 
   808 * Pure: type Type.tsig is superceded by theory in most interfaces.
   809 
   810 * Pure: the Isar proof context type is already defined early in Pure
   811 as Context.proof (note that ProofContext.context and Proof.context are
   812 aliases, where the latter is the preferred name).  This enables other
   813 Isabelle components to refer to that type even before Isar is present.
   814 
   815 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
   816 typeK, constK, axiomK, oracleK), but provide explicit operations for
   817 any of these kinds.  For example, Sign.intern typeK is now
   818 Sign.intern_type, Theory.hide_space Sign.typeK is now
   819 Theory.hide_types.  Also note that former
   820 Theory.hide_classes/types/consts are now
   821 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
   822 internalize their arguments!  INCOMPATIBILITY.
   823 
   824 * Pure: get_thm interface (of PureThy and ProofContext) expects
   825 datatype thmref (with constructors Name and NameSelection) instead of
   826 plain string -- INCOMPATIBILITY;
   827 
   828 * Pure: cases produced by proof methods specify options, where NONE
   829 means to remove case bindings -- INCOMPATIBILITY in
   830 (RAW_)METHOD_CASES.
   831 
   832 * Pure: the following operations retrieve axioms or theorems from a
   833 theory node or theory hierarchy, respectively:
   834 
   835   Theory.axioms_of: theory -> (string * term) list
   836   Theory.all_axioms_of: theory -> (string * term) list
   837   PureThy.thms_of: theory -> (string * thm) list
   838   PureThy.all_thms_of: theory -> (string * thm) list
   839 
   840 * Pure: print_tac now outputs the goal through the trace channel.
   841 
   842 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
   843 Reference Toplevel.debug (default false) controls detailed printing
   844 and tracing of low-level exceptions; Toplevel.profiling (default 0)
   845 controls execution profiling -- set to 1 for time and 2 for space
   846 (both increase the runtime).
   847 
   848 * Isar session: The initial use of ROOT.ML is now always timed,
   849 i.e. the log will show the actual process times, in contrast to the
   850 elapsed wall-clock time that the outer shell wrapper produces.
   851 
   852 * Simplifier: improved handling of bound variables (nameless
   853 representation, avoid allocating new strings).  Simprocs that invoke
   854 the Simplifier recursively should use Simplifier.inherit_bounds to
   855 avoid local name clashes.
   856 
   857 * Provers: Simplifier and Classical Reasoner now support proof context
   858 dependent plug-ins (simprocs, solvers, wrappers etc.).  These extra
   859 components are stored in the theory and patched into the
   860 simpset/claset when used in an Isar proof context.  Context dependent
   861 components are maintained by the following theory operations:
   862 
   863   Simplifier.add_context_simprocs
   864   Simplifier.del_context_simprocs
   865   Simplifier.set_context_subgoaler
   866   Simplifier.reset_context_subgoaler
   867   Simplifier.add_context_looper
   868   Simplifier.del_context_looper
   869   Simplifier.add_context_unsafe_solver
   870   Simplifier.add_context_safe_solver
   871 
   872   Classical.add_context_safe_wrapper
   873   Classical.del_context_safe_wrapper
   874   Classical.add_context_unsafe_wrapper
   875   Classical.del_context_unsafe_wrapper
   876 
   877 IMPORTANT NOTE: proof tools (methods etc.) need to use
   878 local_simpset_of and local_claset_of to instead of the primitive
   879 Simplifier.get_local_simpset and Classical.get_local_claset,
   880 respectively, in order to see the context dependent fields!
   881 
   882 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
   883 bindings for all theorems stored within a given theory; this may help
   884 in porting non-Isar theories to Isar ones, while keeping ML proof
   885 scripts for the time being.
   886 
   887 
   888 *** System ***
   889 
   890 * Allow symlinks to all proper Isabelle executables (Isabelle,
   891 isabelle, isatool etc.).
   892 
   893 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
   894 isatool doc, isatool mkdir, display_drafts etc.).
   895 
   896 * isatool usedir: option -f allows specification of the ML file to be
   897 used by Isabelle; default is ROOT.ML.
   898 
   899 * New isatool version outputs the version identifier of the Isabelle
   900 distribution being used.
   901 
   902 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
   903 (containing Boolean satisfiability problems) into Isabelle/HOL
   904 theories.
   905 
   906 
   907 
   908 New in Isabelle2004 (April 2004)
   909 --------------------------------
   910 
   911 *** General ***
   912 
   913 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
   914   Replaces linorder.ML.
   915 
   916 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
   917   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
   918   (\<a>...\<z>), are now considered normal letters, and can therefore
   919   be used anywhere where an ASCII letter (a...zA...Z) has until
   920   now. COMPATIBILITY: This obviously changes the parsing of some
   921   terms, especially where a symbol has been used as a binder, say
   922   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
   923   as an identifier.  Fix it by inserting a space around former
   924   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
   925   existing theory and ML files.
   926 
   927 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
   928 
   929 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
   930   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
   931   a normal (but invisible) letter. For multiple letter subscripts repeat
   932   \<^isub> like this: x\<^isub>1\<^isub>2.
   933 
   934 * Pure: There are now sub-/superscripts that can span more than one
   935   character. Text between \<^bsub> and \<^esub> is set in subscript in
   936   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
   937   superscript. The new control characters are not identifier parts.
   938 
   939 * Pure: Control-symbols of the form \<^raw:...> will literally print the
   940   content of "..." to the latex file instead of \isacntrl... . The "..."
   941   may consist of any printable characters excluding the end bracket >.
   942 
   943 * Pure: Using new Isar command "finalconsts" (or the ML functions
   944   Theory.add_finals or Theory.add_finals_i) it is now possible to
   945   declare constants "final", which prevents their being given a definition
   946   later.  It is useful for constants whose behaviour is fixed axiomatically
   947   rather than definitionally, such as the meta-logic connectives.
   948 
   949 * Pure: 'instance' now handles general arities with general sorts
   950   (i.e. intersections of classes),
   951 
   952 * Presentation: generated HTML now uses a CSS style sheet to make layout
   953   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
   954   It can be changed to alter the colors/layout of generated pages.
   955 
   956 
   957 *** Isar ***
   958 
   959 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
   960   cut_tac, subgoal_tac and thin_tac:
   961   - Now understand static (Isar) contexts.  As a consequence, users of Isar
   962     locales are no longer forced to write Isar proof scripts.
   963     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
   964     emulations.
   965   - INCOMPATIBILITY: names of variables to be instantiated may no
   966     longer be enclosed in quotes.  Instead, precede variable name with `?'.
   967     This is consistent with the instantiation attribute "where".
   968 
   969 * Attributes "where" and "of":
   970   - Now take type variables of instantiated theorem into account when reading
   971     the instantiation string.  This fixes a bug that caused instantiated
   972     theorems to have too special types in some circumstances.
   973   - "where" permits explicit instantiations of type variables.
   974 
   975 * Calculation commands "moreover" and "also" no longer interfere with
   976   current facts ("this"), admitting arbitrary combinations with "then"
   977   and derived forms.
   978 
   979 * Locales:
   980   - Goal statements involving the context element "includes" no longer
   981     generate theorems with internal delta predicates (those ending on
   982     "_axioms") in the premise.
   983     Resolve particular premise with <locale>.intro to obtain old form.
   984   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
   985     specification and "includes" elements in goal statement.
   986   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
   987     [intro?] and [elim?] (respectively) by default.
   988   - Experimental command for instantiation of locales in proof contexts:
   989         instantiate <label>[<attrs>]: <loc>
   990     Instantiates locale <loc> and adds all its theorems to the current context
   991     taking into account their attributes.  Label and attrs are optional
   992     modifiers, like in theorem declarations.  If present, names of
   993     instantiated theorems are qualified with <label>, and the attributes
   994     <attrs> are applied after any attributes these theorems might have already.
   995       If the locale has assumptions, a chained fact of the form
   996     "<loc> t1 ... tn" is expected from which instantiations of the parameters
   997     are derived.  The command does not support old-style locales declared
   998     with "locale (open)".
   999       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  1000 
  1001 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  1002   (Isar) contexts.
  1003 
  1004 
  1005 *** HOL ***
  1006 
  1007 * Proof import: new image HOL4 contains the imported library from
  1008   the HOL4 system with about 2500 theorems. It is imported by
  1009   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  1010   can be used like any other Isabelle image.  See
  1011   HOL/Import/HOL/README for more information.
  1012 
  1013 * Simplifier:
  1014   - Much improved handling of linear and partial orders.
  1015     Reasoners for linear and partial orders are set up for type classes
  1016     "linorder" and "order" respectively, and are added to the default simpset
  1017     as solvers.  This means that the simplifier can build transitivity chains
  1018     to solve goals from the assumptions.
  1019   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  1020     of blast or auto after simplification become unnecessary because the goal
  1021     is solved by simplification already.
  1022 
  1023 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  1024     all proved in axiomatic type classes for semirings, rings and fields.
  1025 
  1026 * Numerics:
  1027   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  1028     now formalized using the Ring_and_Field theory mentioned above.
  1029   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  1030     than before, because now they are set up once in a generic manner.
  1031   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  1032     Look for the general versions in Ring_and_Field (and Power if they concern
  1033     exponentiation).
  1034 
  1035 * Type "rat" of the rational numbers is now available in HOL-Complex.
  1036 
  1037 * Records:
  1038   - Record types are now by default printed with their type abbreviation
  1039     instead of the list of all field types. This can be configured via
  1040     the reference "print_record_type_abbr".
  1041   - Simproc "record_upd_simproc" for simplification of multiple updates added
  1042     (not enabled by default).
  1043   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  1044     EX x. x = sel r to True (not enabled by default).
  1045   - Tactic "record_split_simp_tac" to split and simplify records added.
  1046 
  1047 * 'specification' command added, allowing for definition by
  1048   specification.  There is also an 'ax_specification' command that
  1049   introduces the new constants axiomatically.
  1050 
  1051 * arith(_tac) is now able to generate counterexamples for reals as well.
  1052 
  1053 * HOL-Algebra: new locale "ring" for non-commutative rings.
  1054 
  1055 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  1056   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  1057 
  1058 * HOL-Matrix: a first theory for matrices in HOL with an application of
  1059   matrix theory to linear programming.
  1060 
  1061 * Unions and Intersections:
  1062   The latex output syntax of UN and INT has been changed
  1063   from "\Union x \in A. B" to "\Union_{x \in A} B"
  1064   i.e. the index formulae has become a subscript.
  1065   Similarly for "\Union x. B", and for \Inter instead of \Union.
  1066 
  1067 * Unions and Intersections over Intervals:
  1068   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  1069   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  1070   like in normal math, and corresponding versions for < and for intersection.
  1071 
  1072 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  1073   lexicographic dictonary ordering has been added as "lexord".
  1074 
  1075 * ML: the legacy theory structures Int and List have been removed. They had
  1076   conflicted with ML Basis Library structures having the same names.
  1077 
  1078 * 'refute' command added to search for (finite) countermodels.  Only works
  1079   for a fragment of HOL.  The installation of an external SAT solver is
  1080   highly recommended.  See "HOL/Refute.thy" for details.
  1081 
  1082 * 'quickcheck' command: Allows to find counterexamples by evaluating
  1083   formulae under an assignment of free variables to random values.
  1084   In contrast to 'refute', it can deal with inductive datatypes,
  1085   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  1086   for examples.
  1087 
  1088 
  1089 *** HOLCF ***
  1090 
  1091 * Streams now come with concatenation and are part of the HOLCF image
  1092 
  1093 
  1094 
  1095 New in Isabelle2003 (May 2003)
  1096 ------------------------------
  1097 
  1098 *** General ***
  1099 
  1100 * Provers/simplifier:
  1101 
  1102   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  1103     Assumptions are now subject to complete mutual simplification,
  1104     not just from left to right. The simplifier now preserves
  1105     the order of assumptions.
  1106 
  1107     Potential INCOMPATIBILITY:
  1108 
  1109     -- simp sometimes diverges where the old version did
  1110        not, e.g. invoking simp on the goal
  1111 
  1112         [| P (f x); y = x; f x = f y |] ==> Q
  1113 
  1114        now gives rise to the infinite reduction sequence
  1115 
  1116         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  1117 
  1118        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  1119        kind of problem.
  1120 
  1121     -- Tactics combining classical reasoner and simplification (such as auto)
  1122        are also affected by this change, because many of them rely on
  1123        simp. They may sometimes diverge as well or yield a different numbers
  1124        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  1125        in case of problems. Sometimes subsequent calls to the classical
  1126        reasoner will fail because a preceeding call to the simplifier too
  1127        eagerly simplified the goal, e.g. deleted redundant premises.
  1128 
  1129   - The simplifier trace now shows the names of the applied rewrite rules
  1130 
  1131   - You can limit the number of recursive invocations of the simplifier
  1132     during conditional rewriting (where the simplifie tries to solve the
  1133     conditions before applying the rewrite rule):
  1134     ML "simp_depth_limit := n"
  1135     where n is an integer. Thus you can force termination where previously
  1136     the simplifier would diverge.
  1137 
  1138   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  1139 
  1140   - No longer aborts on failed congruence proof.  Instead, the
  1141     congruence is ignored.
  1142 
  1143 * Pure: New generic framework for extracting programs from constructive
  1144   proofs. See HOL/Extraction.thy for an example instantiation, as well
  1145   as HOL/Extraction for some case studies.
  1146 
  1147 * Pure: The main goal of the proof state is no longer shown by default, only
  1148 the subgoals. This behaviour is controlled by a new flag.
  1149    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  1150 (ML: Proof.show_main_goal).
  1151 
  1152 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  1153 rules whose conclusion matches subgoal 1:
  1154       PG menu: Isabelle/Isar -> Show me -> matching rules
  1155 The rules are ordered by how closely they match the subgoal.
  1156 In particular, rules that solve a subgoal outright are displayed first
  1157 (or rather last, the way they are printed).
  1158 (ML: ProofGeneral.print_intros())
  1159 
  1160 * Pure: New flag trace_unify_fail causes unification to print
  1161 diagnostic information (PG: in trace buffer) when it fails. This is
  1162 useful for figuring out why single step proofs like rule, erule or
  1163 assumption failed.
  1164 
  1165 * Pure: Locale specifications now produce predicate definitions
  1166 according to the body of text (covering assumptions modulo local
  1167 definitions); predicate "loc_axioms" covers newly introduced text,
  1168 while "loc" is cumulative wrt. all included locale expressions; the
  1169 latter view is presented only on export into the global theory
  1170 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  1171 on the old view without predicates;
  1172 
  1173 * Pure: predefined locales "var" and "struct" are useful for sharing
  1174 parameters (as in CASL, for example); just specify something like
  1175 ``var x + var y + struct M'' as import;
  1176 
  1177 * Pure: improved thms_containing: proper indexing of facts instead of
  1178 raw theorems; check validity of results wrt. current name space;
  1179 include local facts of proof configuration (also covers active
  1180 locales), cover fixed variables in index; may use "_" in term
  1181 specification; an optional limit for the number of printed facts may
  1182 be given (the default is 40);
  1183 
  1184 * Pure: disallow duplicate fact bindings within new-style theory files
  1185 (batch-mode only);
  1186 
  1187 * Provers: improved induct method: assumptions introduced by case
  1188 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  1189 the goal statement); "foo" still refers to all facts collectively;
  1190 
  1191 * Provers: the function blast.overloaded has been removed: all constants
  1192 are regarded as potentially overloaded, which improves robustness in exchange
  1193 for slight decrease in efficiency;
  1194 
  1195 * Provers/linorder: New generic prover for transitivity reasoning over
  1196 linear orders.  Note: this prover is not efficient!
  1197 
  1198 * Isar: preview of problems to finish 'show' now produce an error
  1199 rather than just a warning (in interactive mode);
  1200 
  1201 
  1202 *** HOL ***
  1203 
  1204 * arith(_tac)
  1205 
  1206  - Produces a counter example if it cannot prove a goal.
  1207    Note that the counter example may be spurious if the goal is not a formula
  1208    of quantifier-free linear arithmetic.
  1209    In ProofGeneral the counter example appears in the trace buffer.
  1210 
  1211  - Knows about div k and mod k where k is a numeral of type nat or int.
  1212 
  1213  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  1214    linear arithmetic fails. This takes account of quantifiers and divisibility.
  1215    Presburger arithmetic can also be called explicitly via presburger(_tac).
  1216 
  1217 * simp's arithmetic capabilities have been enhanced a bit: it now
  1218 takes ~= in premises into account (by performing a case split);
  1219 
  1220 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  1221 are distributed over a sum of terms;
  1222 
  1223 * New tactic "trans_tac" and method "trans" instantiate
  1224 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  1225 "<=", "<" and "=").
  1226 
  1227 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  1228 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  1229 
  1230 * 'typedef' command has new option "open" to suppress the set
  1231 definition;
  1232 
  1233 * functions Min and Max on finite sets have been introduced (theory
  1234 Finite_Set);
  1235 
  1236 * attribute [symmetric] now works for relations as well; it turns
  1237 (x,y) : R^-1 into (y,x) : R, and vice versa;
  1238 
  1239 * induct over a !!-quantified statement (say !!x1..xn):
  1240   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  1241 
  1242 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  1243 %x. None. Warning: empty_def now refers to the previously hidden definition
  1244 of the empty set.
  1245 
  1246 * Algebra: formalization of classical algebra.  Intended as base for
  1247 any algebraic development in Isabelle.  Currently covers group theory
  1248 (up to Sylow's theorem) and ring theory (Universal Property of
  1249 Univariate Polynomials).  Contributions welcome;
  1250 
  1251 * GroupTheory: deleted, since its material has been moved to Algebra;
  1252 
  1253 * Complex: new directory of the complex numbers with numeric constants,
  1254 nonstandard complex numbers, and some complex analysis, standard and
  1255 nonstandard (Jacques Fleuriot);
  1256 
  1257 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  1258 
  1259 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  1260 Fleuriot);
  1261 
  1262 * Real/HahnBanach: updated and adapted to locales;
  1263 
  1264 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  1265 Gray and Kramer);
  1266 
  1267 * UNITY: added the Meier-Sanders theory of progress sets;
  1268 
  1269 * MicroJava: bytecode verifier and lightweight bytecode verifier
  1270 as abstract algorithms, instantiated to the JVM;
  1271 
  1272 * Bali: Java source language formalization. Type system, operational
  1273 semantics, axiomatic semantics. Supported language features:
  1274 classes, interfaces, objects,virtual methods, static methods,
  1275 static/instance fields, arrays, access modifiers, definite
  1276 assignment, exceptions.
  1277 
  1278 
  1279 *** ZF ***
  1280 
  1281 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  1282 universe, etc.);
  1283 
  1284 * Main ZF: virtually all theories converted to new-style format;
  1285 
  1286 
  1287 *** ML ***
  1288 
  1289 * Pure: Tactic.prove provides sane interface for internal proofs;
  1290 omits the infamous "standard" operation, so this is more appropriate
  1291 than prove_goalw_cterm in many situations (e.g. in simprocs);
  1292 
  1293 * Pure: improved error reporting of simprocs;
  1294 
  1295 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  1296 up simprocs;
  1297 
  1298 
  1299 *** Document preparation ***
  1300 
  1301 * uses \par instead of \\ for line breaks in theory text. This may
  1302 shift some page breaks in large documents. To get the old behaviour
  1303 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  1304 
  1305 * minimized dependencies of isabelle.sty and isabellesym.sty on
  1306 other packages
  1307 
  1308 * \<euro> now needs package babel/greek instead of marvosym (which
  1309 broke \Rightarrow)
  1310 
  1311 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  1312 textcomp package)
  1313 
  1314 
  1315 
  1316 New in Isabelle2002 (March 2002)
  1317 --------------------------------
  1318 
  1319 *** Document preparation ***
  1320 
  1321 * greatly simplified document preparation setup, including more
  1322 graceful interpretation of isatool usedir -i/-d/-D options, and more
  1323 instructive isatool mkdir; users should basically be able to get
  1324 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  1325 users may run a separate document processing stage manually like this:
  1326 "isatool usedir -D output HOL Test && isatool document Test/output";
  1327 
  1328 * theory dependency graph may now be incorporated into documents;
  1329 isatool usedir -g true will produce session_graph.eps/.pdf for use
  1330 with \includegraphics of LaTeX;
  1331 
  1332 * proper spacing of consecutive markup elements, especially text
  1333 blocks after section headings;
  1334 
  1335 * support bold style (for single symbols only), input syntax is like
  1336 this: "\<^bold>\<alpha>" or "\<^bold>A";
  1337 
  1338 * \<bullet> is now output as bold \cdot by default, which looks much
  1339 better in printed text;
  1340 
  1341 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  1342 note that these symbols are currently unavailable in Proof General /
  1343 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  1344 
  1345 * isatool latex no longer depends on changed TEXINPUTS, instead
  1346 isatool document copies the Isabelle style files to the target
  1347 location;
  1348 
  1349 
  1350 *** Isar ***
  1351 
  1352 * Pure/Provers: improved proof by cases and induction;
  1353   - 'case' command admits impromptu naming of parameters (such as
  1354     "case (Suc n)");
  1355   - 'induct' method divinates rule instantiation from the inductive
  1356     claim; no longer requires excessive ?P bindings for proper
  1357     instantiation of cases;
  1358   - 'induct' method properly enumerates all possibilities of set/type
  1359     rules; as a consequence facts may be also passed through *type*
  1360     rules without further ado;
  1361   - 'induct' method now derives symbolic cases from the *rulified*
  1362     rule (before it used to rulify cases stemming from the internal
  1363     atomized version); this means that the context of a non-atomic
  1364     statement becomes is included in the hypothesis, avoiding the
  1365     slightly cumbersome show "PROP ?case" form;
  1366   - 'induct' may now use elim-style induction rules without chaining
  1367     facts, using ``missing'' premises from the goal state; this allows
  1368     rules stemming from inductive sets to be applied in unstructured
  1369     scripts, while still benefitting from proper handling of non-atomic
  1370     statements; NB: major inductive premises need to be put first, all
  1371     the rest of the goal is passed through the induction;
  1372   - 'induct' proper support for mutual induction involving non-atomic
  1373     rule statements (uses the new concept of simultaneous goals, see
  1374     below);
  1375   - append all possible rule selections, but only use the first
  1376     success (no backtracking);
  1377   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  1378   - undeclared rule case names default to numbers 1, 2, 3, ...;
  1379   - added 'print_induct_rules' (covered by help item in recent Proof
  1380     General versions);
  1381   - moved induct/cases attributes to Pure, methods to Provers;
  1382   - generic method setup instantiated for FOL and HOL;
  1383 
  1384 * Pure: support multiple simultaneous goal statements, for example
  1385 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  1386 meta-level mechanism, this acts as if several individual goals had
  1387 been stated separately; in particular common proof methods need to be
  1388 repeated in order to cover all claims; note that a single elimination
  1389 step is *not* sufficient to establish the two conjunctions, so this
  1390 fails:
  1391 
  1392   assume "A & B" then have A and B ..   (*".." fails*)
  1393 
  1394 better use "obtain" in situations as above; alternative refer to
  1395 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  1396 
  1397 * Pure: proper integration with ``locales''; unlike the original
  1398 version by Florian Kammller, Isar locales package high-level proof
  1399 contexts rather than raw logical ones (e.g. we admit to include
  1400 attributes everywhere); operations on locales include merge and
  1401 rename; support for implicit arguments (``structures''); simultaneous
  1402 type-inference over imports and text; see also HOL/ex/Locales.thy for
  1403 some examples;
  1404 
  1405 * Pure: the following commands have been ``localized'', supporting a
  1406 target locale specification "(in name)": 'lemma', 'theorem',
  1407 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  1408 stored both within the locale and at the theory level (exported and
  1409 qualified by the locale name);
  1410 
  1411 * Pure: theory goals may now be specified in ``long'' form, with
  1412 ad-hoc contexts consisting of arbitrary locale elements. for example
  1413 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  1414 definitions may be given, too); the result is a meta-level rule with
  1415 the context elements being discharged in the obvious way;
  1416 
  1417 * Pure: new proof command 'using' allows to augment currently used
  1418 facts after a goal statement ('using' is syntactically analogous to
  1419 'apply', but acts on the goal's facts only); this allows chained facts
  1420 to be separated into parts given before and after a claim, as in
  1421 ``from a and b have C using d and e <proof>'';
  1422 
  1423 * Pure: renamed "antecedent" case to "rule_context";
  1424 
  1425 * Pure: new 'judgment' command records explicit information about the
  1426 object-logic embedding (used by several tools internally); no longer
  1427 use hard-wired "Trueprop";
  1428 
  1429 * Pure: added 'corollary' command;
  1430 
  1431 * Pure: fixed 'token_translation' command;
  1432 
  1433 * Pure: removed obsolete 'exported' attribute;
  1434 
  1435 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  1436 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  1437 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  1438 
  1439 * Pure: method 'atomize' presents local goal premises as object-level
  1440 statements (atomic meta-level propositions); setup controlled via
  1441 rewrite rules declarations of 'atomize' attribute; example
  1442 application: 'induct' method with proper rule statements in improper
  1443 proof *scripts*;
  1444 
  1445 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  1446 now consider the syntactic context of assumptions, giving a better
  1447 chance to get type-inference of the arguments right (this is
  1448 especially important for locales);
  1449 
  1450 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  1451 mode;
  1452 
  1453 * Pure/obtain: the formal conclusion "thesis", being marked as
  1454 ``internal'', may no longer be reference directly in the text;
  1455 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  1456 situations;
  1457 
  1458 * Pure: generic 'sym' attribute which declares a rule both as pure
  1459 'elim?' and for the 'symmetric' operation;
  1460 
  1461 * Pure: marginal comments ``--'' may now occur just anywhere in the
  1462 text; the fixed correlation with particular command syntax has been
  1463 discontinued;
  1464 
  1465 * Pure: new method 'rules' is particularly well-suited for proof
  1466 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  1467 but often produces more compact proof terms with less detours;
  1468 
  1469 * Pure/Provers/classical: simplified integration with pure rule
  1470 attributes and methods; the classical "intro?/elim?/dest?"
  1471 declarations coincide with the pure ones; the "rule" method no longer
  1472 includes classically swapped intros; "intro" and "elim" methods no
  1473 longer pick rules from the context; also got rid of ML declarations
  1474 AddXIs/AddXEs/AddXDs; all of this has some potential for
  1475 INCOMPATIBILITY;
  1476 
  1477 * Provers/classical: attribute 'swapped' produces classical inversions
  1478 of introduction rules;
  1479 
  1480 * Provers/simplifier: 'simplified' attribute may refer to explicit
  1481 rules instead of full simplifier context; 'iff' attribute handles
  1482 conditional rules;
  1483 
  1484 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  1485 
  1486 * HOL: 'recdef' now fails on unfinished automated proofs, use
  1487 "(permissive)" option to recover old behavior;
  1488 
  1489 * HOL: 'inductive' no longer features separate (collective) attributes
  1490 for 'intros' (was found too confusing);
  1491 
  1492 * HOL: properly declared induction rules less_induct and
  1493 wf_induct_rule;
  1494 
  1495 
  1496 *** HOL ***
  1497 
  1498 * HOL: moved over to sane numeral syntax; the new policy is as
  1499 follows:
  1500 
  1501   - 0 and 1 are polymorphic constants, which are defined on any
  1502   numeric type (nat, int, real etc.);
  1503 
  1504   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  1505   binary representation internally;
  1506 
  1507   - type nat has special constructor Suc, and generally prefers Suc 0
  1508   over 1::nat and Suc (Suc 0) over 2::nat;
  1509 
  1510 This change may cause significant problems of INCOMPATIBILITY; here
  1511 are some hints on converting existing sources:
  1512 
  1513   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  1514   entities, so expressions involving "-" (unary or binary minus) need
  1515   to be spaced properly;
  1516 
  1517   - existing occurrences of "1" may need to be constraint "1::nat" or
  1518   even replaced by Suc 0; similar for old "2";
  1519 
  1520   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  1521 
  1522   - remove all special provisions on numerals in proofs;
  1523 
  1524 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  1525 representation (depends on bin_arith_simps in the default context);
  1526 
  1527 * HOL: symbolic syntax for x^2 (numeral 2);
  1528 
  1529 * HOL: the class of all HOL types is now called "type" rather than
  1530 "term"; INCOMPATIBILITY, need to adapt references to this type class
  1531 in axclass/classes, instance/arities, and (usually rare) occurrences
  1532 in typings (of consts etc.); internally the class is called
  1533 "HOL.type", ML programs should refer to HOLogic.typeS;
  1534 
  1535 * HOL/record package improvements:
  1536   - new derived operations "fields" to build a partial record section,
  1537     "extend" to promote a fixed record to a record scheme, and
  1538     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  1539     declared as simp by default;
  1540   - shared operations ("more", "fields", etc.) now need to be always
  1541     qualified) --- potential INCOMPATIBILITY;
  1542   - removed "make_scheme" operations (use "make" with "extend") --
  1543     INCOMPATIBILITY;
  1544   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  1545   - provides cases/induct rules for use with corresponding Isar
  1546     methods (for concrete records, record schemes, concrete more
  1547     parts, and schematic more parts -- in that order);
  1548   - internal definitions directly based on a light-weight abstract
  1549     theory of product types over typedef rather than datatype;
  1550 
  1551 * HOL: generic code generator for generating executable ML code from
  1552 specifications; specific support for HOL constructs such as inductive
  1553 datatypes and sets, as well as recursive functions; can be invoked
  1554 via 'generate_code' theory section;
  1555 
  1556 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  1557 
  1558 * HOL: consolidated and renamed several theories.  In particular:
  1559         Ord.thy has been absorbed into HOL.thy
  1560         String.thy has been absorbed into List.thy
  1561 
  1562 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  1563 (beware of argument permutation!);
  1564 
  1565 * HOL: linorder_less_split superseded by linorder_cases;
  1566 
  1567 * HOL/List: "nodups" renamed to "distinct";
  1568 
  1569 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  1570 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  1571   - Ex_def has changed, now need to use some_eq_ex
  1572 
  1573 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  1574 in this (rare) case use:
  1575 
  1576   delSWrapper "split_all_tac"
  1577   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  1578 
  1579 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  1580 MAY FAIL;
  1581 
  1582 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  1583 Isabelle's type classes, ^ on functions and relations has too general
  1584 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  1585 necessary to attach explicit type constraints;
  1586 
  1587 * HOL/Relation: the prefix name of the infix "O" has been changed from
  1588 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  1589 renamed accordingly (eg "compI" -> "rel_compI").
  1590 
  1591 * HOL: syntax translations now work properly with numerals and records
  1592 expressions;
  1593 
  1594 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  1595 of "lam" -- INCOMPATIBILITY;
  1596 
  1597 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  1598 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  1599 renamed "Product_Type.unit";
  1600 
  1601 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  1602 
  1603 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  1604 the "cases" method);
  1605 
  1606 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  1607 Florian Kammller);
  1608 
  1609 * HOL/IMP: updated and converted to new-style theory format; several
  1610 parts turned into readable document, with proper Isar proof texts and
  1611 some explanations (by Gerwin Klein);
  1612 
  1613 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  1614 
  1615 * HOL-Hyperreal is now a logic image;
  1616 
  1617 
  1618 *** HOLCF ***
  1619 
  1620 * Isar: consts/constdefs supports mixfix syntax for continuous
  1621 operations;
  1622 
  1623 * Isar: domain package adapted to new-style theory format, e.g. see
  1624 HOLCF/ex/Dnat.thy;
  1625 
  1626 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  1627 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  1628 lift.induct_tac, always use UU instead of Undef;
  1629 
  1630 * HOLCF/IMP: updated and converted to new-style theory;
  1631 
  1632 
  1633 *** ZF ***
  1634 
  1635 * Isar: proper integration of logic-specific tools and packages,
  1636 including theory commands '(co)inductive', '(co)datatype',
  1637 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  1638 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  1639 
  1640 * theory Main no longer includes AC; for the Axiom of Choice, base
  1641 your theory on Main_ZFC;
  1642 
  1643 * the integer library now covers quotients and remainders, with many
  1644 laws relating division to addition, multiplication, etc.;
  1645 
  1646 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  1647 typeless version of the formalism;
  1648 
  1649 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  1650 format;
  1651 
  1652 * ZF/Induct: new directory for examples of inductive definitions,
  1653 including theory Multiset for multiset orderings; converted to
  1654 new-style theory format;
  1655 
  1656 * ZF: many new theorems about lists, ordinals, etc.;
  1657 
  1658 
  1659 *** General ***
  1660 
  1661 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  1662 variable proof controls level of detail: 0 = no proofs (only oracle
  1663 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  1664 also ref manual for further ML interfaces;
  1665 
  1666 * Pure/axclass: removed obsolete ML interface
  1667 goal_subclass/goal_arity;
  1668 
  1669 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  1670 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  1671 separate tokens, so expressions involving minus need to be spaced
  1672 properly;
  1673 
  1674 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  1675 rather than "infixl" or "infixr";
  1676 
  1677 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  1678 sort constraint specifications in type inference; e.g. "x::_::foo"
  1679 ensures that the type of "x" is of sort "foo" (but not necessarily a
  1680 type variable);
  1681 
  1682 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  1683 control output of nested => (types); the default behavior is
  1684 "type_brackets";
  1685 
  1686 * Pure/syntax: builtin parse translation for "_constify" turns valued
  1687 tokens into AST constants;
  1688 
  1689 * Pure/syntax: prefer later declarations of translations and print
  1690 translation functions; potential INCOMPATIBILITY: need to reverse
  1691 multiple declarations for same syntax element constant;
  1692 
  1693 * Pure/show_hyps reset by default (in accordance to existing Isar
  1694 practice);
  1695 
  1696 * Provers/classical: renamed addaltern to addafter, addSaltern to
  1697 addSafter;
  1698 
  1699 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  1700 as well;
  1701 
  1702 * system: tested support for MacOS X; should be able to get Isabelle +
  1703 Proof General to work in a plain Terminal after installing Poly/ML
  1704 (e.g. from the Isabelle distribution area) and GNU bash alone
  1705 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  1706 support requires further installations, e.g. from
  1707 http://fink.sourceforge.net/);
  1708 
  1709 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  1710 
  1711 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  1712 of 40 MB), cf. ML_OPTIONS;
  1713 
  1714 * system: Proof General keywords specification is now part of the
  1715 Isabelle distribution (see etc/isar-keywords.el);
  1716 
  1717 * system: support for persistent Proof General sessions (refrain from
  1718 outdating all loaded theories on startup); user may create writable
  1719 logic images like this: ``isabelle -q HOL Test'';
  1720 
  1721 * system: smart selection of Isabelle process versus Isabelle
  1722 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  1723 run both "isabelle" and "Isabelle" even if file names are badly
  1724 damaged (executable inspects the case of the first letter of its own
  1725 name); added separate "isabelle-process" and "isabelle-interface";
  1726 
  1727 * system: refrain from any attempt at filtering input streams; no
  1728 longer support ``8bit'' encoding of old isabelle font, instead proper
  1729 iso-latin characters may now be used; the related isatools
  1730 "symbolinput" and "nonascii" have disappeared as well;
  1731 
  1732 * system: removed old "xterm" interface (the print modes "xterm" and
  1733 "xterm_color" are still available for direct use in a suitable
  1734 terminal);
  1735 
  1736 
  1737 
  1738 New in Isabelle99-2 (February 2001)
  1739 -----------------------------------
  1740 
  1741 *** Overview of INCOMPATIBILITIES ***
  1742 
  1743 * HOL: please note that theories in the Library and elsewhere often use the
  1744 new-style (Isar) format; to refer to their theorems in an ML script you must
  1745 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  1746 
  1747 * HOL: inductive package no longer splits induction rule aggressively,
  1748 but only as far as specified by the introductions given; the old
  1749 format may be recovered via ML function complete_split_rule or attribute
  1750 'split_rule (complete)';
  1751 
  1752 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  1753 gfp_Tarski to gfp_unfold;
  1754 
  1755 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  1756 
  1757 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  1758 relation); infix "^^" has been renamed "``"; infix "``" has been
  1759 renamed "`"; "univalent" has been renamed "single_valued";
  1760 
  1761 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  1762 operation;
  1763 
  1764 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  1765 
  1766 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  1767 
  1768 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  1769 consequence, it is no longer monotonic wrt. the local goal context
  1770 (which is now passed through the inductive cases);
  1771 
  1772 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  1773 \<gg> to \<ggreater>;
  1774 
  1775 
  1776 *** Document preparation ***
  1777 
  1778 * \isabellestyle{NAME} selects version of Isabelle output (currently
  1779 available: are "it" for near math-mode best-style output, "sl" for
  1780 slanted text style, and "tt" for plain type-writer; if no
  1781 \isabellestyle command is given, output is according to slanted
  1782 type-writer);
  1783 
  1784 * support sub/super scripts (for single symbols only), input syntax is
  1785 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  1786 
  1787 * some more standard symbols; see Appendix A of the system manual for
  1788 the complete list of symbols defined in isabellesym.sty;
  1789 
  1790 * improved isabelle style files; more abstract symbol implementation
  1791 (should now use \isamath{...} and \isatext{...} in custom symbol
  1792 definitions);
  1793 
  1794 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  1795 state; Note that presentation of goal states does not conform to
  1796 actual human-readable proof documents.  Please do not include goal
  1797 states into document output unless you really know what you are doing!
  1798 
  1799 * proper indentation of antiquoted output with proportional LaTeX
  1800 fonts;
  1801 
  1802 * no_document ML operator temporarily disables LaTeX document
  1803 generation;
  1804 
  1805 * isatool unsymbolize tunes sources for plain ASCII communication;
  1806 
  1807 
  1808 *** Isar ***
  1809 
  1810 * Pure: Isar now suffers initial goal statements to contain unbound
  1811 schematic variables (this does not conform to actual readable proof
  1812 documents, due to unpredictable outcome and non-compositional proof
  1813 checking); users who know what they are doing may use schematic goals
  1814 for Prolog-style synthesis of proven results;
  1815 
  1816 * Pure: assumption method (an implicit finishing) now handles actual
  1817 rules as well;
  1818 
  1819 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  1820 initial goal, declare "that" only as Pure intro (only for single
  1821 steps); the "that" rule assumption may now be involved in implicit
  1822 finishing, thus ".." becomes a feasible for trivial obtains;
  1823 
  1824 * Pure: default proof step now includes 'intro_classes'; thus trivial
  1825 instance proofs may be performed by "..";
  1826 
  1827 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  1828 statements as well;
  1829 
  1830 * Pure: more robust selection of calculational rules;
  1831 
  1832 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  1833 rule (as well as the assumption rule);
  1834 
  1835 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  1836 lemmas, using the graph browser tool;
  1837 
  1838 * Pure: predict failure of "show" in interactive mode;
  1839 
  1840 * Pure: 'thms_containing' now takes actual terms as arguments;
  1841 
  1842 * HOL: improved method 'induct' --- now handles non-atomic goals
  1843 (potential INCOMPATIBILITY); tuned error handling;
  1844 
  1845 * HOL: cases and induct rules now provide explicit hints about the
  1846 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  1847 any remaining facts are inserted into the goal verbatim;
  1848 
  1849 * HOL: local contexts (aka cases) may now contain term bindings as
  1850 well; the 'cases' and 'induct' methods new provide a ?case binding for
  1851 the result to be shown in each case;
  1852 
  1853 * HOL: added 'recdef_tc' command;
  1854 
  1855 * isatool convert assists in eliminating legacy ML scripts;
  1856 
  1857 
  1858 *** HOL ***
  1859 
  1860 * HOL/Library: a collection of generic theories to be used together
  1861 with main HOL; the theory loader path already includes this directory
  1862 by default; the following existing theories have been moved here:
  1863 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  1864 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  1865 
  1866 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  1867 modelling and verification task performed in Isabelle/HOL +
  1868 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  1869 
  1870 * HOL/Algebra: special summation operator SUM no longer exists, it has
  1871 been replaced by setsum; infix 'assoc' now has priority 50 (like
  1872 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  1873 'domain', this makes the theory consistent with mathematical
  1874 literature;
  1875 
  1876 * HOL basics: added overloaded operations "inverse" and "divide"
  1877 (infix "/"), syntax for generic "abs" operation, generic summation
  1878 operator \<Sum>;
  1879 
  1880 * HOL/typedef: simplified package, provide more useful rules (see also
  1881 HOL/subset.thy);
  1882 
  1883 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  1884 now expressed as a proper nested rule (old-style tactic scripts may
  1885 require atomize_strip_tac to cope with non-atomic premises);
  1886 
  1887 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  1888 to "split_conv" (old name still available for compatibility);
  1889 
  1890 * HOL: improved concrete syntax for strings (e.g. allows translation
  1891 rules with string literals);
  1892 
  1893 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  1894  and Fleuriot's mechanization of analysis, including the transcendental
  1895  functions for the reals;
  1896 
  1897 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  1898 
  1899 
  1900 *** CTT ***
  1901 
  1902 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  1903 "lam" is displayed as TWO lambda-symbols
  1904 
  1905 * CTT: theory Main now available, containing everything (that is, Bool
  1906 and Arith);
  1907 
  1908 
  1909 *** General ***
  1910 
  1911 * Pure: the Simplifier has been implemented properly as a derived rule
  1912 outside of the actual kernel (at last!); the overall performance
  1913 penalty in practical applications is about 50%, while reliability of
  1914 the Isabelle inference kernel has been greatly improved;
  1915 
  1916 * print modes "brackets" and "no_brackets" control output of nested =>
  1917 (types) and ==> (props); the default behaviour is "brackets";
  1918 
  1919 * Provers: fast_tac (and friends) now handle actual object-logic rules
  1920 as assumptions as well;
  1921 
  1922 * system: support Poly/ML 4.0;
  1923 
  1924 * system: isatool install handles KDE version 1 or 2;
  1925 
  1926 
  1927 
  1928 New in Isabelle99-1 (October 2000)
  1929 ----------------------------------
  1930 
  1931 *** Overview of INCOMPATIBILITIES ***
  1932 
  1933 * HOL: simplification of natural numbers is much changed; to partly
  1934 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  1935 issue the following ML commands:
  1936 
  1937   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  1938   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  1939 
  1940 * HOL: simplification no longer dives into case-expressions; this is
  1941 controlled by "t.weak_case_cong" for each datatype t;
  1942 
  1943 * HOL: nat_less_induct renamed to less_induct;
  1944 
  1945 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  1946 fixsome to patch .thy and .ML sources automatically;
  1947 
  1948   select_equality  -> some_equality
  1949   select_eq_Ex     -> some_eq_ex
  1950   selectI2EX       -> someI2_ex
  1951   selectI2         -> someI2
  1952   selectI          -> someI
  1953   select1_equality -> some1_equality
  1954   Eps_sym_eq       -> some_sym_eq_trivial
  1955   Eps_eq           -> some_eq_trivial
  1956 
  1957 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  1958 
  1959 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  1960 instead);
  1961 
  1962 * HOL: the recursion equations generated by 'recdef' are now called
  1963 f.simps instead of f.rules;
  1964 
  1965 * HOL: qed_spec_mp now also handles bounded ALL as well;
  1966 
  1967 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  1968 sometimes be needed;
  1969 
  1970 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  1971 
  1972 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  1973 
  1974 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  1975 product is now "<*>" instead of "Times"; the lexicographic product is
  1976 now "<*lex*>" instead of "**";
  1977 
  1978 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  1979 of main HOL, but was unused); better use HOL's datatype package;
  1980 
  1981 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  1982 the old syntax may be recovered as follows:
  1983 
  1984   syntax (symbols)
  1985     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  1986       (infixl "\\<oplus>" 100)
  1987 
  1988 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  1989 
  1990 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  1991 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  1992 internally;
  1993 
  1994 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  1995 changed from A/r to A//r;
  1996 
  1997 * ZF: new treatment of arithmetic (nat & int) may break some old
  1998 proofs;
  1999 
  2000 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  2001 rulify -> rule_format, elimify -> elim_format, ...);
  2002 
  2003 * Isar/Provers: intro/elim/dest attributes changed; renamed
  2004 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  2005 should have to change intro!! to intro? only); replaced "delrule" by
  2006 "rule del";
  2007 
  2008 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  2009 
  2010 * Provers: strengthened force_tac by using new first_best_tac;
  2011 
  2012 * LaTeX document preparation: several changes of isabelle.sty (see
  2013 lib/texinputs);
  2014 
  2015 
  2016 *** Document preparation ***
  2017 
  2018 * formal comments (text blocks etc.) in new-style theories may now
  2019 contain antiquotations of thm/prop/term/typ/text to be presented
  2020 according to latex print mode; concrete syntax is like this:
  2021 @{term[show_types] "f(x) = a + x"};
  2022 
  2023 * isatool mkdir provides easy setup of Isabelle session directories,
  2024 including proper document sources;
  2025 
  2026 * generated LaTeX sources are now deleted after successful run
  2027 (isatool document -c); may retain a copy somewhere else via -D option
  2028 of isatool usedir;
  2029 
  2030 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  2031 style files, achieving self-contained LaTeX sources and simplifying
  2032 LaTeX debugging;
  2033 
  2034 * old-style theories now produce (crude) LaTeX output as well;
  2035 
  2036 * browser info session directories are now self-contained (may be put
  2037 on WWW server seperately); improved graphs of nested sessions; removed
  2038 graph for 'all sessions';
  2039 
  2040 * several improvements in isabelle style files; \isabellestyle{it}
  2041 produces fake math mode output; \isamarkupheader is now \section by
  2042 default; see lib/texinputs/isabelle.sty etc.;
  2043 
  2044 
  2045 *** Isar ***
  2046 
  2047 * Isar/Pure: local results and corresponding term bindings are now
  2048 subject to Hindley-Milner polymorphism (similar to ML); this
  2049 accommodates incremental type-inference very nicely;
  2050 
  2051 * Isar/Pure: new derived language element 'obtain' supports
  2052 generalized existence reasoning;
  2053 
  2054 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  2055 support accumulation of results, without applying any rules yet;
  2056 useful to collect intermediate results without explicit name
  2057 references, and for use with transitivity rules with more than 2
  2058 premises;
  2059 
  2060 * Isar/Pure: scalable support for case-analysis type proofs: new
  2061 'case' language element refers to local contexts symbolically, as
  2062 produced by certain proof methods; internally, case names are attached
  2063 to theorems as "tags";
  2064 
  2065 * Isar/Pure: theory command 'hide' removes declarations from
  2066 class/type/const name spaces;
  2067 
  2068 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  2069 indicate potential overloading;
  2070 
  2071 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  2072 
  2073 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  2074 "{a,b,c}" instead of {a,b,c};
  2075 
  2076 * Isar/Pure now provides its own version of intro/elim/dest
  2077 attributes; useful for building new logics, but beware of confusion
  2078 with the version in Provers/classical;
  2079 
  2080 * Isar/Pure: the local context of (non-atomic) goals is provided via
  2081 case name 'antecedent';
  2082 
  2083 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  2084 to the current context is now done automatically);
  2085 
  2086 * Isar/Pure: theory command 'method_setup' provides a simple interface
  2087 for definining proof methods in ML;
  2088 
  2089 * Isar/Provers: intro/elim/dest attributes changed; renamed
  2090 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  2091 most cases, one should have to change intro!! to intro? only);
  2092 replaced "delrule" by "rule del";
  2093 
  2094 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  2095 'symmetric' attribute (the latter supercedes [RS sym]);
  2096 
  2097 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  2098 method modifier); 'simp' method: 'only:' modifier removes loopers as
  2099 well (including splits);
  2100 
  2101 * Isar/Provers: Simplifier and Classical methods now support all kind
  2102 of modifiers used in the past, including 'cong', 'iff', etc.
  2103 
  2104 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  2105 of Simplifier and Classical reasoner);
  2106 
  2107 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  2108 now support named cases; major packages (inductive, datatype, primrec,
  2109 recdef) support case names and properly name parameters;
  2110 
  2111 * Isar/HOL: new transitivity rules for substitution in inequalities --
  2112 monotonicity conditions are extracted to be proven at end of
  2113 calculations;
  2114 
  2115 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  2116 method anyway;
  2117 
  2118 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  2119 split_if split_if_asm; datatype package provides theorems foo.splits =
  2120 foo.split foo.split_asm for each datatype;
  2121 
  2122 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  2123 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  2124 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  2125 use "(cases (simplified))" method in proper proof texts);
  2126 
  2127 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  2128 
  2129 * Isar: names of theorems etc. may be natural numbers as well;
  2130 
  2131 * Isar: 'pr' command: optional arguments for goals_limit and
  2132 ProofContext.prems_limit; no longer prints theory contexts, but only
  2133 proof states;
  2134 
  2135 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  2136 additional print modes to be specified; e.g. "pr(latex)" will print
  2137 proof state according to the Isabelle LaTeX style;
  2138 
  2139 * Isar: improved support for emulating tactic scripts, including proof
  2140 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  2141 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  2142 (for HOL datatypes);
  2143 
  2144 * Isar: simplified (more robust) goal selection of proof methods: 1st
  2145 goal, all goals, or explicit goal specifier (tactic emulation); thus
  2146 'proof method scripts' have to be in depth-first order;
  2147 
  2148 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  2149 
  2150 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  2151 should instead use individual commands for printing items
  2152 (print_commands, print_methods etc.);
  2153 
  2154 * Isar: added 'nothing' --- the empty list of theorems;
  2155 
  2156 
  2157 *** HOL ***
  2158 
  2159 * HOL/MicroJava: formalization of a fragment of Java, together with a
  2160 corresponding virtual machine and a specification of its bytecode
  2161 verifier and a lightweight bytecode verifier, including proofs of
  2162 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  2163 Cornelia Pusch (see also the homepage of project Bali at
  2164 http://isabelle.in.tum.de/Bali/);
  2165 
  2166 * HOL/Algebra: new theory of rings and univariate polynomials, by
  2167 Clemens Ballarin;
  2168 
  2169 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  2170 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  2171 Rasmussen;
  2172 
  2173 * HOL/Lattice: fundamental concepts of lattice theory and order
  2174 structures, including duals, properties of bounds versus algebraic
  2175 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  2176 Theorem for complete lattices etc.; may also serve as a demonstration
  2177 for abstract algebraic reasoning using axiomatic type classes, and
  2178 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  2179 
  2180 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  2181 von Oheimb;
  2182 
  2183 * HOL/IMPP: extension of IMP with local variables and mutually
  2184 recursive procedures, by David von Oheimb;
  2185 
  2186 * HOL/Lambda: converted into new-style theory and document;
  2187 
  2188 * HOL/ex/Multiquote: example of multiple nested quotations and
  2189 anti-quotations -- basically a generalized version of de-Bruijn
  2190 representation; very useful in avoiding lifting of operations;
  2191 
  2192 * HOL/record: added general record equality rule to simpset; fixed
  2193 select-update simplification procedure to handle extended records as
  2194 well; admit "r" as field name;
  2195 
  2196 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  2197 other numeric types and also as the identity of groups, rings, etc.;
  2198 
  2199 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  2200 Types nat and int belong to this axclass;
  2201 
  2202 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  2203    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  2204    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  2205   two terms #m*u and #n*u are replaced by #(m+n)*u
  2206     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  2207   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  2208     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  2209 
  2210 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  2211 powerful prover for predicate logic but knows nothing of clasets; see
  2212 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  2213 
  2214 * HOL: new version of "case_tac" subsumes both boolean case split and
  2215 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  2216 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  2217 
  2218 * HOL: simplification no longer dives into case-expressions: only the
  2219 selector expression is simplified, but not the remaining arms; to
  2220 enable full simplification of case-expressions for datatype t, you may
  2221 remove t.weak_case_cong from the simpset, either globally (Delcongs
  2222 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  2223 
  2224 * HOL/recdef: the recursion equations generated by 'recdef' for
  2225 function 'f' are now called f.simps instead of f.rules; if all
  2226 termination conditions are proved automatically, these simplification
  2227 rules are added to the simpset, as in primrec; rules may be named
  2228 individually as well, resulting in a separate list of theorems for
  2229 each equation;
  2230 
  2231 * HOL/While is a new theory that provides a while-combinator. It
  2232 permits the definition of tail-recursive functions without the
  2233 provision of a termination measure. The latter is necessary once the
  2234 invariant proof rule for while is applied.
  2235 
  2236 * HOL: new (overloaded) notation for the set of elements below/above
  2237 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  2238 
  2239 * HOL: theorems impI, allI, ballI bound as "strip";
  2240 
  2241 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  2242 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  2243 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  2244 
  2245 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  2246 
  2247 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  2248 main HOL, but was unused);
  2249 
  2250 * HOL: fewer consts declared as global (e.g. have to refer to
  2251 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  2252 
  2253 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  2254 in case of overlap with user translations (e.g. judgements over
  2255 tuples); (note that the underlying logical represenation is still
  2256 bogus);
  2257 
  2258 
  2259 *** ZF ***
  2260 
  2261 * ZF: simplification automatically cancels common terms in arithmetic
  2262 expressions over nat and int;
  2263 
  2264 * ZF: new treatment of nat to minimize type-checking: all operators
  2265 coerce their operands to a natural number using the function natify,
  2266 making the algebraic laws unconditional;
  2267 
  2268 * ZF: as above, for int: operators coerce their operands to an integer
  2269 using the function intify;
  2270 
  2271 * ZF: the integer library now contains many of the usual laws for the
  2272 orderings, including $<=, and monotonicity laws for $+ and $*;
  2273 
  2274 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  2275 simplification;
  2276 
  2277 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  2278 to the simplifier and classical reasoner simultaneously;
  2279 
  2280 
  2281 *** General ***
  2282 
  2283 * Provers: blast_tac now handles actual object-logic rules as
  2284 assumptions; note that auto_tac uses blast_tac internally as well;
  2285 
  2286 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  2287 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  2288 
  2289 * Provers: delrules now handles destruct rules as well (no longer need
  2290 explicit make_elim);
  2291 
  2292 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  2293   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  2294 use instead the strong form,
  2295   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  2296 in HOL, FOL and ZF the function cla_make_elim will create such rules
  2297 from destruct-rules;
  2298 
  2299 * Provers: Simplifier.easy_setup provides a fast path to basic
  2300 Simplifier setup for new object-logics;
  2301 
  2302 * Pure: AST translation rules no longer require constant head on LHS;
  2303 
  2304 * Pure: improved name spaces: ambiguous output is qualified; support
  2305 for hiding of names;
  2306 
  2307 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  2308 XSYMBOL_HOME; no longer need to do manual configuration in most
  2309 situations;
  2310 
  2311 * system: compression of ML heaps images may now be controlled via -c
  2312 option of isabelle and isatool usedir (currently only observed by
  2313 Poly/ML);
  2314 
  2315 * system: isatool installfonts may handle X-Symbol fonts as well (very
  2316 useful for remote X11);
  2317 
  2318 * system: provide TAGS file for Isabelle sources;
  2319 
  2320 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  2321 order;
  2322 
  2323 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  2324 timing flag supersedes proof_timing and Toplevel.trace;
  2325 
  2326 * ML: new combinators |>> and |>>> for incremental transformations
  2327 with secondary results (e.g. certain theory extensions):
  2328 
  2329 * ML: PureThy.add_defs gets additional argument to indicate potential
  2330 overloading (usually false);
  2331 
  2332 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  2333 results;
  2334 
  2335 
  2336 
  2337 New in Isabelle99 (October 1999)
  2338 --------------------------------
  2339 
  2340 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  2341 
  2342 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  2343 are no longer simplified.  (This allows the simplifier to unfold recursive
  2344 functional programs.)  To restore the old behaviour, declare
  2345 
  2346     Delcongs [if_weak_cong];
  2347 
  2348 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  2349 complement;
  2350 
  2351 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  2352 
  2353 * HOL/datatype: mutual_induct_tac no longer exists --
  2354   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  2355 
  2356 * HOL/typedef: fixed type inference for representing set; type
  2357 arguments now have to occur explicitly on the rhs as type constraints;
  2358 
  2359 * ZF: The con_defs part of an inductive definition may no longer refer
  2360 to constants declared in the same theory;
  2361 
  2362 * HOL, ZF: the function mk_cases, generated by the inductive
  2363 definition package, has lost an argument.  To simplify its result, it
  2364 uses the default simpset instead of a supplied list of theorems.
  2365 
  2366 * HOL/List: the constructors of type list are now Nil and Cons;
  2367 
  2368 * Simplifier: the type of the infix ML functions
  2369         setSSolver addSSolver setSolver addSolver
  2370 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  2371 for packaging solvers. A solver is created via
  2372         mk_solver: string -> (thm list -> int -> tactic) -> solver
  2373 where the string argument is only a comment.
  2374 
  2375 
  2376 *** Proof tools ***
  2377 
  2378 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  2379 decision procedure for linear arithmetic. Currently it is used for
  2380 types `nat', `int', and `real' in HOL (see below); it can, should and
  2381 will be instantiated for other types and logics as well.
  2382 
  2383 * The simplifier now accepts rewrite rules with flexible heads, eg
  2384      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  2385   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  2386   matching.
  2387 
  2388 
  2389 *** General ***
  2390 
  2391 * New Isabelle/Isar subsystem provides an alternative to traditional
  2392 tactical theorem proving; together with the ProofGeneral/isar user
  2393 interface it offers an interactive environment for developing human
  2394 readable proof documents (Isar == Intelligible semi-automated
  2395 reasoning); for further information see isatool doc isar-ref,
  2396 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  2397 
  2398 * improved and simplified presentation of theories: better HTML markup
  2399 (including colors), graph views in several sizes; isatool usedir now
  2400 provides a proper interface for user theories (via -P option); actual
  2401 document preparation based on (PDF)LaTeX is available as well (for
  2402 new-style theories only); see isatool doc system for more information;
  2403 
  2404 * native support for Proof General, both for classic Isabelle and
  2405 Isabelle/Isar;
  2406 
  2407 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  2408 using the graph browser tool;
  2409 
  2410 * Isabelle manuals now also available as PDF;
  2411 
  2412 * theory loader rewritten from scratch (may not be fully
  2413 bug-compatible); old loadpath variable has been replaced by show_path,
  2414 add_path, del_path, reset_path functions; new operations such as
  2415 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  2416 isatool doc ref);
  2417 
  2418 * improved isatool install: option -k creates KDE application icon,
  2419 option -p DIR installs standalone binaries;
  2420 
  2421 * added ML_PLATFORM setting (useful for cross-platform installations);
  2422 more robust handling of platform specific ML images for SML/NJ;
  2423 
  2424 * the settings environment is now statically scoped, i.e. it is never
  2425 created again in sub-processes invoked from isabelle, isatool, or
  2426 Isabelle;
  2427 
  2428 * path element specification '~~' refers to '$ISABELLE_HOME';
  2429 
  2430 * in locales, the "assumes" and "defines" parts may be omitted if
  2431 empty;
  2432 
  2433 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  2434 long arrows);
  2435 
  2436 * new print_mode "HTML";
  2437 
  2438 * new flag show_tags controls display of tags of theorems (which are
  2439 basically just comments that may be attached by some tools);
  2440 
  2441 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  2442 mode and goal output format:
  2443 
  2444 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  2445 244c244
  2446 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  2447 ---
  2448 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  2449 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  2450 181c181
  2451 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  2452 ---
  2453 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  2454 
  2455 * function bind_thms stores lists of theorems (cf. bind_thm);
  2456 
  2457 * new shorthand tactics ftac, eatac, datac, fatac;
  2458 
  2459 * qed (and friends) now accept "" as result name; in that case the
  2460 theorem is not stored, but proper checks and presentation of the
  2461 result still apply;
  2462 
  2463 * theorem database now also indexes constants "Trueprop", "all",
  2464 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  2465 
  2466 
  2467 *** HOL ***
  2468 
  2469 ** HOL arithmetic **
  2470 
  2471 * There are now decision procedures for linear arithmetic over nat and
  2472 int:
  2473 
  2474 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  2475 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  2476 are treated as atomic; subformulae not involving type `nat' or `int'
  2477 are ignored; quantified subformulae are ignored unless they are
  2478 positive universal or negative existential. The tactic has to be
  2479 invoked by hand and can be a little bit slow. In particular, the
  2480 running time is exponential in the number of occurrences of `min' and
  2481 `max', and `-' on `nat'.
  2482 
  2483 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  2484 (negated) (in)equalities among the premises and the conclusion into
  2485 account (i.e. no compound formulae) and does not know about `min' and
  2486 `max', and `-' on `nat'. It is fast and is used automatically by the
  2487 simplifier.
  2488 
  2489 NB: At the moment, these decision procedures do not cope with mixed
  2490 nat/int formulae where the two parts interact, such as `m < n ==>
  2491 int(m) < int(n)'.
  2492 
  2493 * HOL/Numeral provides a generic theory of numerals (encoded
  2494 efficiently as bit strings); setup for types nat/int/real is in place;
  2495 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  2496 int, existing theories and proof scripts may require a few additional
  2497 type constraints;
  2498 
  2499 * integer division and remainder can now be performed on constant
  2500 arguments;
  2501 
  2502 * many properties of integer multiplication, division and remainder
  2503 are now available;
  2504 
  2505 * An interface to the Stanford Validity Checker (SVC) is available through the
  2506 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  2507 are proved automatically.  SVC must be installed separately, and its results
  2508 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  2509 invocation of the underlying oracle).  For SVC see
  2510   http://verify.stanford.edu/SVC
  2511 
  2512 * IsaMakefile: the HOL-Real target now builds an actual image;
  2513 
  2514 
  2515 ** HOL misc **
  2516 
  2517 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  2518 (in Isabelle/Isar) -- by Gertrud Bauer;
  2519 
  2520 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  2521 analysis for assembly languages with subtypes;
  2522 
  2523 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  2524 -- avoids syntactic ambiguities and treats state, transition, and
  2525 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  2526 changed syntax and (many) tactics;
  2527 
  2528 * HOL/inductive: Now also handles more general introduction rules such
  2529   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  2530   theorems are now maintained within the theory (maintained via the
  2531   "mono" attribute);
  2532 
  2533 * HOL/datatype: Now also handles arbitrarily branching datatypes
  2534   (using function types) such as
  2535 
  2536   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  2537 
  2538 * HOL/record: record_simproc (part of the default simpset) takes care
  2539 of selectors applied to updated records; record_split_tac is no longer
  2540 part of the default claset; update_defs may now be removed from the
  2541 simpset in many cases; COMPATIBILITY: old behavior achieved by
  2542 
  2543   claset_ref () := claset() addSWrapper record_split_wrapper;
  2544   Delsimprocs [record_simproc]
  2545 
  2546 * HOL/typedef: fixed type inference for representing set; type
  2547 arguments now have to occur explicitly on the rhs as type constraints;
  2548 
  2549 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  2550 names rather than an ML expression;
  2551 
  2552 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  2553 supplied later.  Program schemes can be defined, such as
  2554     "While B C s = (if B s then While B C (C s) else s)"
  2555 where the well-founded relation can be chosen after B and C have been given.
  2556 
  2557 * HOL/List: the constructors of type list are now Nil and Cons;
  2558 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  2559 course, ML tools referring to List.list.op # etc. have to be adapted;
  2560 
  2561 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  2562 disabled by default; run isabelle with option -m HOL to get back to
  2563 the original Gordon/HOL-style output;
  2564 
  2565 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  2566 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  2567 
  2568 * HOL basic syntax simplified (more orthogonal): all variants of
  2569 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  2570 Eps operator is provided as well: "SOME x. P[x]";
  2571 
  2572 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  2573 
  2574 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  2575 thus available for user theories;
  2576 
  2577 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  2578 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  2579 time;
  2580 
  2581 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  2582 several times and then mp;
  2583 
  2584 
  2585 *** LK ***
  2586 
  2587 * the notation <<...>> is now available as a notation for sequences of
  2588 formulas;
  2589 
  2590 * the simplifier is now installed
  2591 
  2592 * the axiom system has been generalized (thanks to Soren Heilmann)
  2593 
  2594 * the classical reasoner now has a default rule database
  2595 
  2596 
  2597 *** ZF ***
  2598 
  2599 * new primrec section allows primitive recursive functions to be given
  2600 directly (as in HOL) over datatypes and the natural numbers;
  2601 
  2602 * new tactics induct_tac and exhaust_tac for induction (or case
  2603 analysis) over datatypes and the natural numbers;
  2604 
  2605 * the datatype declaration of type T now defines the recursor T_rec;
  2606 
  2607 * simplification automatically does freeness reasoning for datatype
  2608 constructors;
  2609 
  2610 * automatic type-inference, with AddTCs command to insert new
  2611 type-checking rules;
  2612 
  2613 * datatype introduction rules are now added as Safe Introduction rules
  2614 to the claset;
  2615 
  2616 * the syntax "if P then x else y" is now available in addition to
  2617 if(P,x,y);
  2618 
  2619 
  2620 *** Internal programming interfaces ***
  2621 
  2622 * tuned simplifier trace output; new flag debug_simp;
  2623 
  2624 * structures Vartab / Termtab (instances of TableFun) offer efficient
  2625 tables indexed by indexname_ord / term_ord (compatible with aconv);
  2626 
  2627 * AxClass.axclass_tac lost the theory argument;
  2628 
  2629 * tuned current_goals_markers semantics: begin / end goal avoids
  2630 printing empty lines;
  2631 
  2632 * removed prs and prs_fn hook, which was broken because it did not
  2633 include \n in its semantics, forcing writeln to add one
  2634 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  2635 string -> unit if you really want to output text without newline;
  2636 
  2637 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  2638 plain output, interface builders may have to enable 'isabelle_font'
  2639 mode to get Isabelle font glyphs as before;
  2640 
  2641 * refined token_translation interface; INCOMPATIBILITY: output length
  2642 now of type real instead of int;
  2643 
  2644 * theory loader actions may be traced via new ThyInfo.add_hook
  2645 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  2646 your own database of information attached to *whole* theories -- as
  2647 opposed to intra-theory data slots offered via TheoryDataFun;
  2648 
  2649 * proper handling of dangling sort hypotheses (at last!);
  2650 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  2651 extra sort hypotheses that can be witnessed from the type signature;
  2652 the force_strip_shyps flag is gone, any remaining shyps are simply
  2653 left in the theorem (with a warning issued by strip_shyps_warning);
  2654 
  2655 
  2656 
  2657 New in Isabelle98-1 (October 1998)
  2658 ----------------------------------
  2659 
  2660 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  2661 
  2662 * several changes of automated proof tools;
  2663 
  2664 * HOL: major changes to the inductive and datatype packages, including
  2665 some minor incompatibilities of theory syntax;
  2666 
  2667 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  2668 called `inj_on';
  2669 
  2670 * HOL: removed duplicate thms in Arith:
  2671   less_imp_add_less  should be replaced by  trans_less_add1
  2672   le_imp_add_le      should be replaced by  trans_le_add1
  2673 
  2674 * HOL: unary minus is now overloaded (new type constraints may be
  2675 required);
  2676 
  2677 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  2678 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  2679 now taken as an integer constant.
  2680 
  2681 * Pure: ML function 'theory_of' renamed to 'theory';
  2682 
  2683 
  2684 *** Proof tools ***
  2685 
  2686 * Simplifier:
  2687   1. Asm_full_simp_tac is now more aggressive.
  2688      1. It will sometimes reorient premises if that increases their power to
  2689         simplify.
  2690      2. It does no longer proceed strictly from left to right but may also
  2691         rotate premises to achieve further simplification.
  2692      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  2693      old Asm_full_simp_tac in that it does not rotate premises.
  2694   2. The simplifier now knows a little bit about nat-arithmetic.
  2695 
  2696 * Classical reasoner: wrapper mechanism for the classical reasoner now
  2697 allows for selected deletion of wrappers, by introduction of names for
  2698 wrapper functionals.  This implies that addbefore, addSbefore,
  2699 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  2700 and that adding two tactics with the same name overwrites the first
  2701 one (emitting a warning).
  2702   type wrapper = (int -> tactic) -> (int -> tactic)
  2703   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  2704   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  2705   delWrapper, delSWrapper: claset *  string            -> claset
  2706   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  2707 
  2708 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  2709 semantics; addbefore now affects only the unsafe part of step_tac
  2710 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  2711 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  2712 by Force_tac;
  2713 
  2714 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  2715 compWrapper; added safe wrapper (and access functions for it);
  2716 
  2717 * HOL/split_all_tac is now much faster and fails if there is nothing
  2718 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  2719 and the names of the automatically generated variables have changed.
  2720 split_all_tac has moved within claset() from unsafe wrappers to safe
  2721 wrappers, which means that !!-bound variables are split much more
  2722 aggressively, and safe_tac and clarify_tac now split such variables.
  2723 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  2724 Note: the same holds for record_split_tac, which does the job of
  2725 split_all_tac for record fields.
  2726 
  2727 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  2728 permanently to the default simpset using Addsplits just like
  2729 Addsimps. They can be removed via Delsplits just like
  2730 Delsimps. Lower-case versions are also available.
  2731 
  2732 * HOL/Simplifier: The rule split_if is now part of the default
  2733 simpset. This means that the simplifier will eliminate all occurrences
  2734 of if-then-else in the conclusion of a goal. To prevent this, you can
  2735 either remove split_if completely from the default simpset by
  2736 `Delsplits [split_if]' or remove it in a specific call of the
  2737 simplifier using `... delsplits [split_if]'.  You can also add/delete
  2738 other case splitting rules to/from the default simpset: every datatype
  2739 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  2740 t is the name of the datatype).
  2741 
  2742 * Classical reasoner / Simplifier combination: new force_tac (and
  2743 derivatives Force_tac, force) combines rewriting and classical
  2744 reasoning (and whatever other tools) similarly to auto_tac, but is
  2745 aimed to solve the given subgoal completely.
  2746 
  2747 
  2748 *** General ***
  2749 
  2750 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  2751 and `goalw': the theory is no longer needed as an explicit argument -
  2752 the current theory context is used; assumptions are no longer returned
  2753 at the ML-level unless one of them starts with ==> or !!; it is
  2754 recommended to convert to these new commands using isatool fixgoal
  2755 (backup your sources first!);
  2756 
  2757 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  2758 the current theory context, and 'theory' to lookup stored theories;
  2759 
  2760 * new theory section 'locale' for declaring constants, assumptions and
  2761 definitions that have local scope;
  2762 
  2763 * new theory section 'nonterminals' for purely syntactic types;
  2764 
  2765 * new theory section 'setup' for generic ML setup functions
  2766 (e.g. package initialization);
  2767 
  2768 * the distribution now includes Isabelle icons: see
  2769 lib/logo/isabelle-{small,tiny}.xpm;
  2770 
  2771 * isatool install - install binaries with absolute references to
  2772 ISABELLE_HOME/bin;
  2773 
  2774 * isatool logo -- create instances of the Isabelle logo (as EPS);
  2775 
  2776 * print mode 'emacs' reserved for Isamode;
  2777 
  2778 * support multiple print (ast) translations per constant name;
  2779 
  2780 * theorems involving oracles are now printed with a suffixed [!];
  2781 
  2782 
  2783 *** HOL ***
  2784 
  2785 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  2786 
  2787 * HOL/inductive package reorganized and improved: now supports mutual
  2788 definitions such as
  2789 
  2790   inductive EVEN ODD
  2791     intrs
  2792       null "0 : EVEN"
  2793       oddI "n : EVEN ==> Suc n : ODD"
  2794       evenI "n : ODD ==> Suc n : EVEN"
  2795 
  2796 new theorem list "elims" contains an elimination rule for each of the
  2797 recursive sets; inductive definitions now handle disjunctive premises
  2798 correctly (also ZF);
  2799 
  2800 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  2801 "mutual_induct" no longer exists - the induction rule is always
  2802 contained in "induct";
  2803 
  2804 
  2805 * HOL/datatype package re-implemented and greatly improved: now
  2806 supports mutually recursive datatypes such as
  2807 
  2808   datatype
  2809     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  2810             | SUM ('a aexp) ('a aexp)
  2811             | DIFF ('a aexp) ('a aexp)
  2812             | NUM 'a
  2813   and
  2814     'a bexp = LESS ('a aexp) ('a aexp)
  2815             | AND ('a bexp) ('a bexp)
  2816             | OR ('a bexp) ('a bexp)
  2817 
  2818 as well as indirectly recursive datatypes such as
  2819 
  2820   datatype
  2821     ('a, 'b) term = Var 'a
  2822                   | App 'b ((('a, 'b) term) list)
  2823 
  2824 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  2825 induction on mutually / indirectly recursive datatypes.
  2826 
  2827 Primrec equations are now stored in theory and can be accessed via
  2828 <function_name>.simps.
  2829 
  2830 INCOMPATIBILITIES:
  2831 
  2832   - Theories using datatypes must now have theory Datatype as an
  2833     ancestor.
  2834   - The specific <typename>.induct_tac no longer exists - use the
  2835     generic induct_tac instead.
  2836   - natE has been renamed to nat.exhaust - use exhaust_tac
  2837     instead of res_inst_tac ... natE. Note that the variable
  2838     names in nat.exhaust differ from the names in natE, this
  2839     may cause some "fragile" proofs to fail.
  2840   - The theorems split_<typename>_case and split_<typename>_case_asm
  2841     have been renamed to <typename>.split and <typename>.split_asm.
  2842   - Since default sorts of type variables are now handled correctly,
  2843     some datatype definitions may have to be annotated with explicit
  2844     sort constraints.
  2845   - Primrec definitions no longer require function name and type
  2846     of recursive argument.
  2847 
  2848 Consider using isatool fixdatatype to adapt your theories and proof
  2849 scripts to the new package (backup your sources first!).
  2850 
  2851 
  2852 * HOL/record package: considerably improved implementation; now
  2853 includes concrete syntax for record types, terms, updates; theorems
  2854 for surjective pairing and splitting !!-bound record variables; proof
  2855 support is as follows:
  2856 
  2857   1) standard conversions (selectors or updates applied to record
  2858 constructor terms) are part of the standard simpset;
  2859 
  2860   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  2861 made part of standard simpset and claset via addIffs;
  2862 
  2863   3) a tactic for record field splitting (record_split_tac) is part of
  2864 the standard claset (addSWrapper);
  2865 
  2866 To get a better idea about these rules you may retrieve them via
  2867 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  2868 the name of your record type.
  2869 
  2870 The split tactic 3) conceptually simplifies by the following rule:
  2871 
  2872   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  2873 
  2874 Thus any record variable that is bound by meta-all will automatically
  2875 blow up into some record constructor term, consequently the
  2876 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  2877 solve record problems automatically.
  2878 
  2879 
  2880 * reorganized the main HOL image: HOL/Integ and String loaded by
  2881 default; theory Main includes everything;
  2882 
  2883 * automatic simplification of integer sums and comparisons, using cancellation;
  2884 
  2885 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  2886 
  2887 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  2888 
  2889 * many new identities for unions, intersections, set difference, etc.;
  2890 
  2891 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  2892 called split_if, split_split, split_sum_case and split_nat_case (to go
  2893 with add/delsplits);
  2894 
  2895 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  2896 (?x::unit) = (); this is made part of the default simpset, which COULD
  2897 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  2898 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  2899 unit_abs_eta_conv is added in order to counter the effect of
  2900 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  2901 %u.f();
  2902 
  2903 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  2904 makes more sense);
  2905 
  2906 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  2907   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  2908   disjointness reasoning but breaking a few old proofs.
  2909 
  2910 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  2911 to 'converse' from 'inverse' (for compatibility with ZF and some
  2912 literature);
  2913 
  2914 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  2915 the well-founded relation;
  2916 
  2917 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  2918     Compl A.  The "Compl" syntax remains available as input syntax for this
  2919     release ONLY.
  2920 
  2921 * HOL/Update: new theory of function updates:
  2922     f(a:=b) == %x. if x=a then b else f x
  2923 may also be iterated as in f(a:=b,c:=d,...);
  2924 
  2925 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  2926 
  2927 * HOL/List:
  2928   - new function list_update written xs[i:=v] that updates the i-th
  2929     list position. May also be iterated as in xs[i:=a,j:=b,...].
  2930   - new function `upt' written [i..j(] which generates the list
  2931     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  2932     bound write [i..j], which is a shorthand for [i..j+1(].
  2933   - new lexicographic orderings and corresponding wellfoundedness theorems.
  2934 
  2935 * HOL/Arith:
  2936   - removed 'pred' (predecessor) function;
  2937   - generalized some theorems about n-1;
  2938   - many new laws about "div" and "mod";
  2939   - new laws about greatest common divisors (see theory ex/Primes);
  2940 
  2941 * HOL/Relation: renamed the relational operator r^-1 "converse"
  2942 instead of "inverse";
  2943 
  2944 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  2945   of the multiset ordering;
  2946 
  2947 * directory HOL/Real: a construction of the reals using Dedekind cuts
  2948   (not included by default);
  2949 
  2950 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  2951 
  2952 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  2953   programs, i.e. different program variables may have different types.
  2954 
  2955 * calling (stac rew i) now fails if "rew" has no effect on the goal
  2956   [previously, this check worked only if the rewrite rule was unconditional]
  2957   Now rew can involve either definitions or equalities (either == or =).
  2958 
  2959 
  2960 *** ZF ***
  2961 
  2962 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  2963   only the theorems proved on ZF.ML;
  2964 
  2965 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  2966   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  2967   disjointness reasoning but breaking a few old proofs.
  2968 
  2969 * ZF/Update: new theory of function updates
  2970     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  2971   may also be iterated as in f(a:=b,c:=d,...);
  2972 
  2973 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  2974 
  2975 * calling (stac rew i) now fails if "rew" has no effect on the goal
  2976   [previously, this check worked only if the rewrite rule was unconditional]
  2977   Now rew can involve either definitions or equalities (either == or =).
  2978 
  2979 * case_tac provided for compatibility with HOL
  2980     (like the old excluded_middle_tac, but with subgoals swapped)
  2981 
  2982 
  2983 *** Internal programming interfaces ***
  2984 
  2985 * Pure: several new basic modules made available for general use, see
  2986 also src/Pure/README;
  2987 
  2988 * improved the theory data mechanism to support encapsulation (data
  2989 kind name replaced by private Object.kind, acting as authorization
  2990 key); new type-safe user interface via functor TheoryDataFun; generic
  2991 print_data function becomes basically useless;
  2992 
  2993 * removed global_names compatibility flag -- all theory declarations
  2994 are qualified by default;
  2995 
  2996 * module Pure/Syntax now offers quote / antiquote translation
  2997 functions (useful for Hoare logic etc. with implicit dependencies);
  2998 see HOL/ex/Antiquote for an example use;
  2999 
  3000 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  3001 cterm -> thm;
  3002 
  3003 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  3004 subgoal;
  3005 
  3006 * Display.print_goals function moved to Locale.print_goals;
  3007 
  3008 * standard print function for goals supports current_goals_markers
  3009 variable for marking begin of proof, end of proof, start of goal; the
  3010 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  3011 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  3012 for example;
  3013 
  3014 
  3015 
  3016 New in Isabelle98 (January 1998)
  3017 --------------------------------
  3018 
  3019 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3020 
  3021 * changed lexical syntax of terms / types: dots made part of long
  3022 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  3023 
  3024 * simpset (and claset) reference variable replaced by functions
  3025 simpset / simpset_ref;
  3026 
  3027 * no longer supports theory aliases (via merge) and non-trivial
  3028 implicit merge of thms' signatures;
  3029 
  3030 * most internal names of constants changed due to qualified names;
  3031 
  3032 * changed Pure/Sequence interface (see Pure/seq.ML);
  3033 
  3034 
  3035 *** General Changes ***
  3036 
  3037 * hierachically structured name spaces (for consts, types, axms, thms
  3038 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  3039 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  3040 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  3041 long_names for fully qualified output names; NOTE: ML programs
  3042 (special tactics, packages etc.) referring to internal names may have
  3043 to be adapted to cope with fully qualified names; in case of severe
  3044 backward campatibility problems try setting 'global_names' at compile
  3045 time to have enrything declared within a flat name space; one may also
  3046 fine tune name declarations in theories via the 'global' and 'local'
  3047 section;
  3048 
  3049 * reimplemented the implicit simpset and claset using the new anytype
  3050 data filed in signatures; references simpset:simpset ref etc. are
  3051 replaced by functions simpset:unit->simpset and
  3052 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  3053 to patch your ML files accordingly;
  3054 
  3055 * HTML output now includes theory graph data for display with Java
  3056 applet or isatool browser; data generated automatically via isatool
  3057 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  3058 
  3059 * defs may now be conditional; improved rewrite_goals_tac to handle
  3060 conditional equations;
  3061 
  3062 * defs now admits additional type arguments, using TYPE('a) syntax;
  3063 
  3064 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  3065 creates a new theory node; implicit merge of thms' signatures is
  3066 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  3067 transfer:theory->thm->thm in (rare) cases;
  3068 
  3069 * improved handling of draft signatures / theories; draft thms (and
  3070 ctyps, cterms) are automatically promoted to real ones;
  3071 
  3072 * slightly changed interfaces for oracles: admit many per theory, named
  3073 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  3074 
  3075 * print_goals: optional output of const types (set show_consts and
  3076 show_types);
  3077 
  3078 * improved output of warnings (###) and errors (***);
  3079 
  3080 * subgoal_tac displays a warning if the new subgoal has type variables;
  3081 
  3082 * removed old README and Makefiles;
  3083 
  3084 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  3085 
  3086 * removed obsolete init_pps and init_database;
  3087 
  3088 * deleted the obsolete tactical STATE, which was declared by
  3089     fun STATE tacfun st = tacfun st st;
  3090 
  3091 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  3092 (which abbreviates $HOME);
  3093 
  3094 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  3095 use isatool fixseq to adapt your ML programs (this works for fully
  3096 qualified references to the Sequence structure only!);
  3097 
  3098 * use_thy no longer requires writable current directory; it always
  3099 reloads .ML *and* .thy file, if either one is out of date;
  3100 
  3101 
  3102 *** Classical Reasoner ***
  3103 
  3104 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  3105 tactics that use classical reasoning to simplify a subgoal without
  3106 splitting it into several subgoals;
  3107 
  3108 * Safe_tac: like safe_tac but uses the default claset;
  3109 
  3110 
  3111 *** Simplifier ***
  3112 
  3113 * added simplification meta rules:
  3114     (asm_)(full_)simplify: simpset -> thm -> thm;
  3115 
  3116 * simplifier.ML no longer part of Pure -- has to be loaded by object
  3117 logics (again);
  3118 
  3119 * added prems argument to simplification procedures;
  3120 
  3121 * HOL, FOL, ZF: added infix function `addsplits':
  3122   instead of `<simpset> setloop (split_tac <thms>)'
  3123   you can simply write `<simpset> addsplits <thms>'
  3124 
  3125 
  3126 *** Syntax ***
  3127 
  3128 * TYPE('a) syntax for type reflection terms;
  3129 
  3130 * no longer handles consts with name "" -- declare as 'syntax' instead;
  3131 
  3132 * pretty printer: changed order of mixfix annotation preference (again!);
  3133 
  3134 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  3135 
  3136 
  3137 *** HOL ***
  3138 
  3139 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  3140   with `addloop' of the simplifier to faciliate case splitting in premises.
  3141 
  3142 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  3143 
  3144 * HOL/Auth: new protocol proofs including some for the Internet
  3145   protocol TLS;
  3146 
  3147 * HOL/Map: new theory of `maps' a la VDM;
  3148 
  3149 * HOL/simplifier: simplification procedures nat_cancel_sums for
  3150 cancelling out common nat summands from =, <, <= (in)equalities, or
  3151 differences; simplification procedures nat_cancel_factor for
  3152 cancelling common factor from =, <, <= (in)equalities over natural
  3153 sums; nat_cancel contains both kinds of procedures, it is installed by
  3154 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  3155 
  3156 * HOL/simplifier: terms of the form
  3157   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  3158   are rewritten to
  3159   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  3160   and those of the form
  3161   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  3162   are rewritten to
  3163   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  3164 
  3165 * HOL/datatype
  3166   Each datatype `t' now comes with a theorem `split_t_case' of the form
  3167 
  3168   P(t_case f1 ... fn x) =
  3169      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  3170         ...
  3171        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  3172      )
  3173 
  3174   and a theorem `split_t_case_asm' of the form
  3175 
  3176   P(t_case f1 ... fn x) =
  3177     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  3178         ...
  3179        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  3180      )
  3181   which can be added to a simpset via `addsplits'. The existing theorems
  3182   expand_list_case and expand_option_case have been renamed to
  3183   split_list_case and split_option_case.
  3184 
  3185 * HOL/Arithmetic:
  3186   - `pred n' is automatically converted to `n-1'.
  3187     Users are strongly encouraged not to use `pred' any longer,
  3188     because it will disappear altogether at some point.
  3189   - Users are strongly encouraged to write "0 < n" rather than
  3190     "n ~= 0". Theorems and proof tools have been modified towards this
  3191     `standard'.
  3192 
  3193 * HOL/Lists:
  3194   the function "set_of_list" has been renamed "set" (and its theorems too);
  3195   the function "nth" now takes its arguments in the reverse order and
  3196   has acquired the infix notation "!" as in "xs!n".
  3197 
  3198 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  3199 
  3200 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  3201   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  3202 
  3203 * HOL/record: extensible records with schematic structural subtyping
  3204 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  3205 still lacks various theorems and concrete record syntax;
  3206 
  3207 
  3208 *** HOLCF ***
  3209 
  3210 * removed "axioms" and "generated by" sections;
  3211 
  3212 * replaced "ops" section by extended "consts" section, which is capable of
  3213   handling the continuous function space "->" directly;
  3214 
  3215 * domain package:
  3216   . proves theorems immediately and stores them in the theory,
  3217   . creates hierachical name space,
  3218   . now uses normal mixfix annotations (instead of cinfix...),
  3219   . minor changes to some names and values (for consistency),
  3220   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  3221   . separator between mutual domain defs: changed "," to "and",
  3222   . improved handling of sort constraints;  now they have to
  3223     appear on the left-hand side of the equations only;
  3224 
  3225 * fixed LAM <x,y,zs>.b syntax;
  3226 
  3227 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  3228 adm (%x. P (t x)), where P is chainfinite and t continuous;
  3229 
  3230 
  3231 *** FOL and ZF ***
  3232 
  3233 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  3234   with `addloop' of the simplifier to faciliate case splitting in premises.
  3235 
  3236 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  3237 in HOL, they strip ALL and --> from proved theorems;
  3238 
  3239 
  3240 
  3241 New in Isabelle94-8 (May 1997)
  3242 ------------------------------
  3243 
  3244 *** General Changes ***
  3245 
  3246 * new utilities to build / run / maintain Isabelle etc. (in parts
  3247 still somewhat experimental); old Makefiles etc. still functional;
  3248 
  3249 * new 'Isabelle System Manual';
  3250 
  3251 * INSTALL text, together with ./configure and ./build scripts;
  3252 
  3253 * reimplemented type inference for greater efficiency, better error
  3254 messages and clean internal interface;
  3255 
  3256 * prlim command for dealing with lots of subgoals (an easier way of
  3257 setting goals_limit);
  3258 
  3259 
  3260 *** Syntax ***
  3261 
  3262 * supports alternative (named) syntax tables (parser and pretty
  3263 printer); internal interface is provided by add_modesyntax(_i);
  3264 
  3265 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  3266 be used in conjunction with the Isabelle symbol font; uses the
  3267 "symbols" syntax table;
  3268 
  3269 * added token_translation interface (may translate name tokens in
  3270 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  3271 the current print_mode); IMPORTANT: user print translation functions
  3272 are responsible for marking newly introduced bounds
  3273 (Syntax.mark_boundT);
  3274 
  3275 * token translations for modes "xterm" and "xterm_color" that display
  3276 names in bold, underline etc. or colors (which requires a color
  3277 version of xterm);
  3278 
  3279 * infixes may now be declared with names independent of their syntax;
  3280 
  3281 * added typed_print_translation (like print_translation, but may
  3282 access type of constant);
  3283 
  3284 
  3285 *** Classical Reasoner ***
  3286 
  3287 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  3288 some limitations.  Blast_tac...
  3289   + ignores addss, addbefore, addafter; this restriction is intrinsic
  3290   + ignores elimination rules that don't have the correct format
  3291         (the conclusion MUST be a formula variable)
  3292   + ignores types, which can make HOL proofs fail
  3293   + rules must not require higher-order unification, e.g. apply_type in ZF
  3294     [message "Function Var's argument not a bound variable" relates to this]
  3295   + its proof strategy is more general but can actually be slower
  3296 
  3297 * substitution with equality assumptions no longer permutes other
  3298 assumptions;
  3299 
  3300 * minor changes in semantics of addafter (now called addaltern); renamed
  3301 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  3302 (and access functions for it);
  3303 
  3304 * improved combination of classical reasoner and simplifier:
  3305   + functions for handling clasimpsets
  3306   + improvement of addss: now the simplifier is called _after_ the
  3307     safe steps.
  3308   + safe variant of addss called addSss: uses safe simplifications
  3309     _during_ the safe steps. It is more complete as it allows multiple
  3310     instantiations of unknowns (e.g. with slow_tac).
  3311 
  3312 *** Simplifier ***
  3313 
  3314 * added interface for simplification procedures (functions that
  3315 produce *proven* rewrite rules on the fly, depending on current
  3316 redex);
  3317 
  3318 * ordering on terms as parameter (used for ordered rewriting);
  3319 
  3320 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  3321 
  3322 * the solver is now split into a safe and an unsafe part.
  3323 This should be invisible for the normal user, except that the
  3324 functions setsolver and addsolver have been renamed to setSolver and
  3325 addSolver; added safe_asm_full_simp_tac;
  3326 
  3327 
  3328 *** HOL ***
  3329 
  3330 * a generic induction tactic `induct_tac' which works for all datatypes and
  3331 also for type `nat';
  3332 
  3333 * a generic case distinction tactic `exhaust_tac' which works for all
  3334 datatypes and also for type `nat';
  3335 
  3336 * each datatype comes with a function `size';
  3337 
  3338 * patterns in case expressions allow tuple patterns as arguments to
  3339 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  3340 
  3341 * primrec now also works with type nat;
  3342 
  3343 * recdef: a new declaration form, allows general recursive functions to be
  3344 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  3345 
  3346 * the constant for negation has been renamed from "not" to "Not" to
  3347 harmonize with FOL, ZF, LK, etc.;
  3348 
  3349 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  3350 infinite lists;
  3351 
  3352 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  3353 
  3354 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  3355 problems in commutative rings, using axiomatic type classes for + and *;
  3356 
  3357 * more examples in HOL/MiniML and HOL/Auth;
  3358 
  3359 * more default rewrite rules for quantifiers, union/intersection;
  3360 
  3361 * a new constant `arbitrary == @x.False';
  3362 
  3363 * HOLCF/IOA replaces old HOL/IOA;
  3364 
  3365 * HOLCF changes: derived all rules and arities
  3366   + axiomatic type classes instead of classes
  3367   + typedef instead of faking type definitions
  3368   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  3369   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  3370   + eliminated the types void, one, tr
  3371   + use unit lift and bool lift (with translations) instead of one and tr
  3372   + eliminated blift from Lift3.thy (use Def instead of blift)
  3373   all eliminated rules are derived as theorems --> no visible changes ;
  3374 
  3375 
  3376 *** ZF ***
  3377 
  3378 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  3379 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  3380 as ZF_cs addSIs [equalityI];
  3381 
  3382 
  3383 
  3384 New in Isabelle94-7 (November 96)
  3385 ---------------------------------
  3386 
  3387 * allowing negative levels (as offsets) in prlev and choplev;
  3388 
  3389 * super-linear speedup for large simplifications;
  3390 
  3391 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  3392 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  3393 FAIL); can suppress it using the command Delsimps (ex_simps @
  3394 all_simps); De Morgan laws are also now included, by default;
  3395 
  3396 * improved printing of ==>  :  ~:
  3397 
  3398 * new object-logic "Sequents" adds linear logic, while replacing LK
  3399 and Modal (thanks to Sara Kalvala);
  3400 
  3401 * HOL/Auth: correctness proofs for authentication protocols;
  3402 
  3403 * HOL: new auto_tac combines rewriting and classical reasoning (many
  3404 examples on HOL/Auth);
  3405 
  3406 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  3407 the rewriter and classical reasoner simultaneously;
  3408 
  3409 * function uresult no longer returns theorems in "standard" format;
  3410 regain previous version by: val uresult = standard o uresult;
  3411 
  3412 
  3413 
  3414 New in Isabelle94-6
  3415 -------------------
  3416 
  3417 * oracles -- these establish an interface between Isabelle and trusted
  3418 external reasoners, which may deliver results as theorems;
  3419 
  3420 * proof objects (in particular record all uses of oracles);
  3421 
  3422 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  3423 
  3424 * "constdefs" section in theory files;
  3425 
  3426 * "primrec" section (HOL) no longer requires names;
  3427 
  3428 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  3429 
  3430 
  3431 
  3432 New in Isabelle94-5
  3433 -------------------
  3434 
  3435 * reduced space requirements;
  3436 
  3437 * automatic HTML generation from theories;
  3438 
  3439 * theory files no longer require "..." (quotes) around most types;
  3440 
  3441 * new examples, including two proofs of the Church-Rosser theorem;
  3442 
  3443 * non-curried (1994) version of HOL is no longer distributed;
  3444 
  3445 
  3446 
  3447 New in Isabelle94-4
  3448 -------------------
  3449 
  3450 * greatly reduced space requirements;
  3451 
  3452 * theory files (.thy) no longer require \...\ escapes at line breaks;
  3453 
  3454 * searchable theorem database (see the section "Retrieving theorems" on
  3455 page 8 of the Reference Manual);
  3456 
  3457 * new examples, including Grabczewski's monumental case study of the
  3458 Axiom of Choice;
  3459 
  3460 * The previous version of HOL renamed to Old_HOL;
  3461 
  3462 * The new version of HOL (previously called CHOL) uses a curried syntax
  3463 for functions.  Application looks like f a b instead of f(a,b);
  3464 
  3465 * Mutually recursive inductive definitions finally work in HOL;
  3466 
  3467 * In ZF, pattern-matching on tuples is now available in all abstractions and
  3468 translates to the operator "split";
  3469 
  3470 
  3471 
  3472 New in Isabelle94-3
  3473 -------------------
  3474 
  3475 * new infix operator, addss, allowing the classical reasoner to
  3476 perform simplification at each step of its search.  Example:
  3477         fast_tac (cs addss ss)
  3478 
  3479 * a new logic, CHOL, the same as HOL, but with a curried syntax
  3480 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  3481 look like (a,b) instead of <a,b>;
  3482 
  3483 * PLEASE NOTE: CHOL will eventually replace HOL!
  3484 
  3485 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  3486 It translates to the operator "split".  A new theory of integers is available;
  3487 
  3488 * In ZF, integer numerals now denote two's-complement binary integers.
  3489 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  3490 
  3491 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  3492 of the Axiom of Choice;
  3493 
  3494 
  3495 
  3496 New in Isabelle94-2
  3497 -------------------
  3498 
  3499 * Significantly faster resolution;
  3500 
  3501 * the different sections in a .thy file can now be mixed and repeated
  3502 freely;
  3503 
  3504 * Database of theorems for FOL, HOL and ZF.  New
  3505 commands including qed, qed_goal and bind_thm store theorems in the database.
  3506 
  3507 * Simple database queries: return a named theorem (get_thm) or all theorems of
  3508 a given theory (thms_of), or find out what theory a theorem was proved in
  3509 (theory_of_thm);
  3510 
  3511 * Bugs fixed in the inductive definition and datatype packages;
  3512 
  3513 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  3514 and HOL_dup_cs obsolete;
  3515 
  3516 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  3517 have been removed;
  3518 
  3519 * Simpler definition of function space in ZF;
  3520 
  3521 * new results about cardinal and ordinal arithmetic in ZF;
  3522 
  3523 * 'subtype' facility in HOL for introducing new types as subsets of existing
  3524 types;
  3525 
  3526 
  3527 $Id$