NEWS
author bulwahn
Mon Nov 22 10:41:54 2010 +0100 (2010-11-22)
changeset 40634 dc124a486f94
parent 40627 becf5d5187cc
child 40636 3bd9512ca486
child 40672 abd4e7358847
permissions -rw-r--r--
adding dependencies to IsaMakefile; adding sledgehammer_tactic in Mirabelle_Test
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
    10 (and thus refers to something like $HOME/.isabelle/IsabelleXXXX),
    11 while the default heap location within that directory lacks that extra
    12 suffix.  This isolates multiple Isabelle installations from each
    13 other, avoiding problems with old settings in new versions.
    14 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
    15 
    16 * Significantly improved Isabelle/Isar implementation manual.
    17 
    18 * Explicit treatment of UTF8 sequences as Isabelle symbols, such that
    19 a Unicode character is treated as a single symbol, not a sequence of
    20 non-ASCII bytes as before.  Since Isabelle/ML string literals may
    21 contain symbols without further backslash escapes, Unicode can now be
    22 used here as well.  Recall that Symbol.explode in ML provides a
    23 consistent view on symbols, while raw explode (or String.explode)
    24 merely give a byte-oriented representation.
    25 
    26 * Theory loading: only the master source file is looked-up in the
    27 implicit load path, all other files are addressed relatively to its
    28 directory.  Minor INCOMPATIBILITY, subtle change in semantics.
    29 
    30 * Special treatment of ML file names has been discontinued.
    31 Historically, optional extensions .ML or .sml were added on demand --
    32 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
    33 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
    34 
    35 * Various options that affect pretty printing etc. are now properly
    36 handled within the context via configuration options, instead of
    37 unsynchronized references.  There are both ML Config.T entities and
    38 Isar declaration attributes to access these.
    39 
    40   ML (Config.T)                 Isar (attribute)
    41 
    42   eta_contract                  eta_contract
    43   show_brackets                 show_brackets
    44   show_sorts                    show_sorts
    45   show_types                    show_types
    46   show_question_marks           show_question_marks
    47   show_consts                   show_consts
    48 
    49   Syntax.ambiguity_level        syntax_ambiguity_level
    50 
    51   Goal_Display.goals_limit      goals_limit
    52   Goal_Display.show_main_goal   show_main_goal
    53 
    54   Thy_Output.display            thy_output_display
    55   Thy_Output.quotes             thy_output_quotes
    56   Thy_Output.indent             thy_output_indent
    57   Thy_Output.source             thy_output_source
    58   Thy_Output.break              thy_output_break
    59 
    60 Note that corresponding "..._default" references in ML may be only
    61 changed globally at the ROOT session setup, but *not* within a theory.
    62 
    63 
    64 *** Pure ***
    65 
    66 * Support for real valued configuration options, using simplistic
    67 floating-point notation that coincides with the inner syntax for
    68 float_token.
    69 
    70 * Support for real valued preferences (with approximative PGIP type).
    71 
    72 * Interpretation command 'interpret' accepts a list of equations like
    73 'interpretation' does.
    74 
    75 * Diagnostic command 'print_interps' prints interpretations in proofs
    76 in addition to interpretations in theories.
    77 
    78 * Discontinued obsolete 'global' and 'local' commands to manipulate
    79 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
    80 Sign.root_path and Sign.local_path may be applied directly where this
    81 feature is still required for historical reasons.
    82 
    83 * Discontinued ancient 'constdefs' command.  INCOMPATIBILITY, use
    84 'definition' instead.
    85 
    86 * Document antiquotations @{class} and @{type} for printing classes
    87 and type constructors.
    88 
    89 
    90 *** HOL ***
    91 
    92 * Theory Multiset provides stable quicksort implementation of sort_key.
    93 
    94 * Quickcheck now has a configurable time limit which is set to 30 seconds
    95 by default. This can be changed by adding [timeout = n] to the quickcheck
    96 command. The time limit for auto quickcheck is still set independently,
    97 by default to 5 seconds.
    98 
    99 * New command 'partial_function' provides basic support for recursive
   100 function definitions over complete partial orders. Concrete instances
   101 are provided for i) the option type, ii) tail recursion on arbitrary
   102 types, and iii) the heap monad of Imperative_HOL. See
   103 HOL/ex/Fundefs.thy and HOL/Imperative_HOL/ex/Linked_Lists.thy for
   104 examples.
   105 
   106 * Predicates `distinct` and `sorted` now defined inductively, with nice
   107 induction rules.  INCOMPATIBILITY: former distinct.simps and sorted.simps
   108 now named distinct_simps and sorted_simps.
   109 
   110 * Constant `contents` renamed to `the_elem`, to free the generic name
   111 contents for other uses.  INCOMPATIBILITY.
   112 
   113 * Dropped old primrec package.  INCOMPATIBILITY.
   114 
   115 * Improved infrastructure for term evaluation using code generator
   116 techniques, in particular static evaluation conversions.
   117 
   118 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   119  
   120 * Renamed lemmas:
   121   expand_fun_eq -> fun_eq_iff
   122   expand_set_eq -> set_eq_iff
   123   set_ext -> set_eqI
   124  INCOMPATIBILITY.
   125 
   126 * Renamed lemma list: nat_number -> eval_nat_numeral
   127 
   128 * Renamed class eq and constant eq (for code generation) to class equal
   129 and constant equal, plus renaming of related facts and various tuning.
   130 INCOMPATIBILITY.
   131 
   132 * Scala (2.8 or higher) has been added to the target languages of
   133 the code generator.
   134 
   135 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   136 
   137 * Removed output syntax "'a ~=> 'b" for "'a => 'b option". INCOMPATIBILITY.
   138 
   139 * Theory SetsAndFunctions has been split into Function_Algebras and Set_Algebras;
   140 canonical names for instance definitions for functions; various improvements.
   141 INCOMPATIBILITY.
   142 
   143 * Records: logical foundation type for records do not carry a '_type' suffix
   144 any longer.  INCOMPATIBILITY.
   145 
   146 * Code generation for records: more idiomatic representation of record types.
   147 Warning: records are not covered by ancient SML code generation any longer.
   148 INCOMPATIBILITY.  In cases of need, a suitable rep_datatype declaration
   149 helps to succeed then:
   150 
   151   record 'a foo = ...
   152   ...
   153   rep_datatype foo_ext ...
   154 
   155 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   156 INCOMPATIBILITY.
   157 
   158 * Quickcheck in locales considers interpretations of that locale for
   159 counter example search.
   160 
   161 * Theory Library/Monad_Syntax provides do-syntax for monad types.  Syntax
   162 in Library/State_Monad has been changed to avoid ambiguities.
   163 INCOMPATIBILITY.
   164 
   165 * Code generator: export_code without explicit file declaration prints
   166 to standard output.  INCOMPATIBILITY.
   167 
   168 * Abolished symbol type names:  "prod" and "sum" replace "*" and "+"
   169 respectively.  INCOMPATIBILITY.
   170 
   171 * Name "Plus" of disjoint sum operator "<+>" is now hidden.
   172   Write Sum_Type.Plus.
   173 
   174 * Constant "split" has been merged with constant "prod_case";  names
   175 of ML functions, facts etc. involving split have been retained so far,
   176 though.  INCOMPATIBILITY.
   177 
   178 * Dropped old infix syntax "mem" for List.member;  use "in set"
   179 instead.  INCOMPATIBILITY.
   180 
   181 * Refactoring of code-generation specific operations in List.thy
   182 
   183   constants
   184     null ~> List.null
   185 
   186   facts
   187     mem_iff ~> member_def
   188     null_empty ~> null_def
   189 
   190 INCOMPATIBILITY.  Note that these were not suppossed to be used
   191 regularly unless for striking reasons;  their main purpose was code
   192 generation.
   193 
   194 * Some previously unqualified names have been qualified:
   195 
   196   types
   197     bool ~> HOL.bool
   198     nat ~> Nat.nat
   199 
   200   constants
   201     Trueprop ~> HOL.Trueprop
   202     True ~> HOL.True
   203     False ~> HOL.False
   204     op & ~> HOL.conj
   205     op | ~> HOL.disj
   206     op --> ~> HOL.implies
   207     op = ~> HOL.eq
   208     Not ~> HOL.Not
   209     The ~> HOL.The
   210     All ~> HOL.All
   211     Ex ~> HOL.Ex
   212     Ex1 ~> HOL.Ex1
   213     Let ~> HOL.Let
   214     If ~> HOL.If
   215     Ball ~> Set.Ball
   216     Bex ~> Set.Bex
   217     Suc ~> Nat.Suc
   218     Pair ~> Product_Type.Pair
   219     fst ~> Product_Type.fst
   220     snd ~> Product_Type.snd
   221     curry ~> Product_Type.curry
   222     op : ~> Set.member
   223     Collect ~> Set.Collect
   224 
   225 INCOMPATIBILITY.
   226 
   227 * Removed simplifier congruence rule of "prod_case", as has for long
   228 been the case with "split".  INCOMPATIBILITY.
   229 
   230 * Datatype package: theorems generated for executable equality
   231 (class eq) carry proper names and are treated as default code
   232 equations.
   233 
   234 * Removed lemma Option.is_none_none (Duplicate of is_none_def).
   235 INCOMPATIBILITY.
   236 
   237 * List.thy: use various operations from the Haskell prelude when
   238 generating Haskell code.
   239 
   240 * Multiset.thy: renamed empty_idemp -> empty_neutral
   241 
   242 * code_simp.ML and method code_simp: simplification with rules determined
   243 by code generator.
   244 
   245 * code generator: do not print function definitions for case
   246 combinators any longer.
   247 
   248 * Multivariate Analysis: Introduced a type class for euclidean space. Most
   249 theorems are now stated in terms of euclidean spaces instead of finite
   250 cartesian products.
   251 
   252   types
   253     real ^ 'n ~>  'a::real_vector
   254               ~>  'a::euclidean_space
   255               ~>  'a::ordered_euclidean_space
   256         (depends on your needs)
   257 
   258   constants
   259      _ $ _        ~> _ $$ _
   260      \<chi> x. _  ~> \<chi>\<chi> x. _
   261      CARD('n)     ~> DIM('a)
   262 
   263 Also note that the indices are now natural numbers and not from some finite
   264 type. Finite cartesian products of euclidean spaces, products of euclidean
   265 spaces the real and complex numbers are instantiated to be euclidean_spaces.
   266 
   267 INCOMPATIBILITY.
   268 
   269 * Probability: Introduced pinfreal as real numbers with infinity. Use pinfreal
   270 as value for measures. Introduces Lebesgue Measure based on the integral in
   271 Multivariate Analysis. Proved Radon Nikodym for arbitrary sigma finite measure
   272 spaces.
   273 
   274  INCOMPATIBILITY.
   275 
   276 * Inductive package: offers new command "inductive_simps" to automatically
   277 derive instantiated and simplified equations for inductive predicates,
   278 similar to inductive_cases.
   279 
   280 * "bij f" is now an abbreviation of "bij_betw f UNIV UNIV". surj_on is a
   281 generalization of surj, and "surj f" is now a abbreviation of "surj_on f UNIV".
   282 The theorems bij_def and surj_def are unchanged.
   283 
   284 * Function package: .psimps rules are no longer implicitly declared [simp].
   285 INCOMPATIBILITY.
   286 
   287 * Weaker versions of the "meson" and "metis" proof methods are now available in
   288   "HOL-Plain", without dependency on "Hilbert_Choice". The proof methods become
   289   more powerful after "Hilbert_Choice" is loaded in "HOL-Main".
   290 
   291 * MESON: Renamed lemmas:
   292   meson_not_conjD ~> Meson.not_conjD
   293   meson_not_disjD ~> Meson.not_disjD
   294   meson_not_notD ~> Meson.not_notD
   295   meson_not_allD ~> Meson.not_allD
   296   meson_not_exD ~> Meson.not_exD
   297   meson_imp_to_disjD ~> Meson.imp_to_disjD
   298   meson_not_impD ~> Meson.not_impD
   299   meson_iff_to_disjD ~> Meson.iff_to_disjD
   300   meson_not_iffD ~> Meson.not_iffD
   301   meson_not_refl_disj_D ~> Meson.not_refl_disj_D
   302   meson_conj_exD1 ~> Meson.conj_exD1
   303   meson_conj_exD2 ~> Meson.conj_exD2
   304   meson_disj_exD ~> Meson.disj_exD
   305   meson_disj_exD1 ~> Meson.disj_exD1
   306   meson_disj_exD2 ~> Meson.disj_exD2
   307   meson_disj_assoc ~> Meson.disj_assoc
   308   meson_disj_comm ~> Meson.disj_comm
   309   meson_disj_FalseD1 ~> Meson.disj_FalseD1
   310   meson_disj_FalseD2 ~> Meson.disj_FalseD2
   311 INCOMPATIBILITY.
   312 
   313 * Auto Solve: Renamed "Auto Solve Direct". The tool is now available manually as
   314   "solve_direct".
   315 
   316 * Sledgehammer:
   317   - Added "smt" and "remote_smt" provers based on the "smt" proof method. See
   318     the Sledgehammer manual for details ("isabelle doc sledgehammer").
   319   - Renamed lemmas:
   320     COMBI_def ~> Meson.COMBI_def
   321     COMBK_def ~> Meson.COMBK_def
   322     COMBB_def ~> Meson.COMBB_def
   323     COMBC_def ~> Meson.COMBC_def
   324     COMBS_def ~> Meson.COMBS_def
   325     abs_I ~> Meson.abs_I
   326     abs_K ~> Meson.abs_K
   327     abs_B ~> Meson.abs_B
   328     abs_C ~> Meson.abs_C
   329     abs_S ~> Meson.abs_S
   330     INCOMPATIBILITY.
   331   - Renamed commands:
   332     sledgehammer atp_info ~> sledgehammer running_provers
   333     sledgehammer atp_kill ~> sledgehammer kill_provers
   334     sledgehammer available_atps ~> sledgehammer available_provers
   335     INCOMPATIBILITY.
   336   - Renamed options:
   337     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   338     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   339     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   340     (and "ms" and "min" are no longer supported)
   341     INCOMPATIBILITY.
   342 
   343 * Nitpick:
   344   - Renamed options:
   345     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   346     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   347     INCOMPATIBILITY.
   348 
   349 * Changed SMT configuration options:
   350   - Renamed:
   351     z3_proofs ~> smt_oracle (with swapped semantics)
   352     z3_trace_assms ~> smt_trace_used_facts
   353     INCOMPATIBILITY.
   354   - Added:
   355     smt_verbose
   356     smt_datatypes
   357     cvc3_options
   358     yices_options
   359 
   360 * Boogie output files (.b2i files) need to be declared in the
   361 theory header.
   362 
   363 * Removed [split_format ... and ... and ...] version of
   364 [split_format].  Potential INCOMPATIBILITY.
   365 
   366 
   367 *** HOLCF ***
   368 
   369 * The domain package now runs in definitional mode by default: The
   370 former command 'new_domain' is now called 'domain'. To use the domain
   371 package in its original axiomatic mode, use 'domain (unsafe)'.
   372 INCOMPATIBILITY.
   373 
   374 * The new class 'domain' is now the default sort; the definitional
   375 domain package and the powerdomain theories both require this class.
   376 The new class 'predomain' is an unpointed version of 'domain'.
   377 Theories can be updated by replacing sort annotations as shown below.
   378 INCOMPATIBILITY.
   379 
   380   'a::type ~> 'a::countable
   381   'a::cpo  ~> 'a::predomain
   382   'a::pcpo ~> 'a::domain
   383 
   384 * The old type class 'rep' has been superseded by class 'domain'.
   385 Accordingly, users of the definitional package must remove any
   386 'default_sort rep' declarations. INCOMPATIBILITY.
   387 
   388 * The old type classes 'profinite' and 'bifinite', along with the
   389 overloaded constant 'approx' have been removed. INCOMPATIBILITY.
   390 
   391 * The type 'udom alg_defl' has been replaced by the non-parameterized
   392 type 'defl'. HOLCF no longer defines an embedding of type defl into
   393 udom by default; the instance proof defl :: domain is now available in
   394 HOLCF/Library/Defl_Bifinite.thy.
   395 
   396 * The syntax 'REP('a)' has been replaced with 'DEFL('a)'.
   397 
   398 * The predicate 'directed' has been removed. INCOMPATIBILITY.
   399 
   400 * The type class 'finite_po' has been removed. INCOMPATIBILITY.
   401 
   402 * Renamed some theorems (the original names are also still available).
   403   expand_fun_below   ~> fun_below_iff
   404   below_fun_ext      ~> fun_belowI
   405   expand_cfun_eq     ~> cfun_eq_iff
   406   ext_cfun           ~> cfun_eqI
   407   expand_cfun_below  ~> cfun_below_iff
   408   below_cfun_ext     ~> cfun_belowI
   409   cont2cont_Rep_CFun ~> cont2cont_APP
   410 
   411 * The Abs and Rep functions for various types have changed names.
   412 Related theorem names have also changed to match. INCOMPATIBILITY. 
   413   Rep_CFun  ~> Rep_cfun
   414   Abs_CFun  ~> Abs_cfun
   415   Rep_Sprod ~> Rep_sprod
   416   Abs_Sprod ~> Abs_sprod
   417   Rep_Ssum  ~> Rep_ssum
   418   Abs_Ssum  ~> Abs_ssum
   419 
   420 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   421 been renamed to *_bottom_iff. INCOMPATIBILITY.
   422 
   423 * Various changes to bisimulation/coinduction with domain package:
   424   - Definitions of 'bisim' constants no longer mention definedness.
   425   - With mutual recursion, 'bisim' predicate is now curried.
   426   - With mutual recursion, each type gets a separate coind theorem.
   427   - Variable names in bisim_def and coinduct rules have changed.
   428 INCOMPATIBILITY.
   429 
   430 * Case combinators generated by the domain package for type 'foo'
   431 are now named 'foo_case' instead of 'foo_when'. INCOMPATIBILITY.
   432 
   433 * Many legacy theorem names have been discontinued. INCOMPATIBILITY.
   434   sq_ord_less_eq_trans ~> below_eq_trans
   435   sq_ord_eq_less_trans ~> eq_below_trans
   436   refl_less            ~> below_refl
   437   trans_less           ~> below_trans
   438   antisym_less         ~> below_antisym
   439   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   440   box_less             ~> box_below
   441   rev_trans_less       ~> rev_below_trans
   442   not_less2not_eq      ~> not_below2not_eq
   443   less_UU_iff          ~> below_UU_iff
   444   flat_less_iff        ~> flat_below_iff
   445   adm_less             ~> adm_below
   446   adm_not_less         ~> adm_not_below
   447   adm_compact_not_less ~> adm_compact_not_below
   448   less_fun_def         ~> below_fun_def
   449   expand_fun_less      ~> fun_below_iff
   450   less_fun_ext         ~> fun_belowI
   451   less_discr_def       ~> below_discr_def
   452   discr_less_eq        ~> discr_below_eq
   453   less_unit_def        ~> below_unit_def
   454   less_cprod_def       ~> below_prod_def
   455   prod_lessI           ~> prod_belowI
   456   Pair_less_iff        ~> Pair_below_iff
   457   fst_less_iff         ~> fst_below_iff
   458   snd_less_iff         ~> snd_below_iff
   459   expand_cfun_less     ~> cfun_below_iff
   460   less_cfun_ext        ~> cfun_belowI
   461   injection_less       ~> injection_below
   462   less_up_def          ~> below_up_def
   463   not_Iup_less         ~> not_Iup_below
   464   Iup_less             ~> Iup_below
   465   up_less              ~> up_below
   466   Def_inject_less_eq   ~> Def_below_Def
   467   Def_less_is_eq       ~> Def_below_iff
   468   spair_less_iff       ~> spair_below_iff
   469   less_sprod           ~> below_sprod
   470   spair_less           ~> spair_below
   471   sfst_less_iff        ~> sfst_below_iff
   472   ssnd_less_iff        ~> ssnd_below_iff
   473   fix_least_less       ~> fix_least_below
   474   dist_less_one        ~> dist_below_one
   475   less_ONE             ~> below_ONE
   476   ONE_less_iff         ~> ONE_below_iff
   477   less_sinlD           ~> below_sinlD
   478   less_sinrD           ~> below_sinrD
   479 
   480 
   481 *** FOL ***
   482 
   483 * All constant names are now qualified.  INCOMPATIBILITY.
   484 
   485 
   486 *** ZF ***
   487 
   488 * All constant names are now qualified.  INCOMPATIBILITY.
   489 
   490 
   491 *** ML ***
   492 
   493 * Renamed raw "explode" function to "raw_explode" to emphasize its
   494 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   495 almost all situations.
   496 
   497 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   498 See implementation manual for further details on exceptions in
   499 Isabelle/ML.
   500 
   501 * Antiquotation @{assert} inlines a function bool -> unit that raises
   502 Fail if the argument is false.  Due to inlining the source position of
   503 failed assertions is included in the error output.
   504 
   505 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   506 text is in practice always evaluated with a stable theory checkpoint.
   507 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   508 
   509 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   510 meaning.
   511 
   512 * Renamed structure PureThy to Pure_Thy and moved most of its
   513 operations to structure Global_Theory, to emphasize that this is
   514 rarely-used global-only stuff.
   515 
   516 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   517 instead (or tracing for high-volume output).
   518 
   519 * Configuration option show_question_marks only affects regular pretty
   520 printing of types and terms, not raw Term.string_of_vname.
   521 
   522 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   523 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   524 @{thms} for most purposes.
   525 
   526 * ML structure Unsynchronized never opened, not even in Isar
   527 interaction mode as before.  Old Unsynchronized.set etc. have been
   528 discontinued -- use plain := instead.  This should be *rare* anyway,
   529 since modern tools always work via official context data, notably
   530 configuration options.
   531 
   532 * ML antiquotations @{theory} and @{theory_ref} refer to named
   533 theories from the ancestry of the current context, not any accidental
   534 theory loader state as before.  Potential INCOMPATIBILITY, subtle
   535 change in semantics.
   536 
   537 * Parallel and asynchronous execution requires special care concerning
   538 interrupts.  Structure Exn provides some convenience functions that
   539 avoid working directly with raw Interrupt.  User code must not absorb
   540 interrupts -- intermediate handling (for cleanup etc.) needs to be
   541 followed by re-raising of the original exception.  Another common
   542 source of mistakes are "handle _" patterns, which make the meaning of
   543 the program subject to physical effects of the environment.
   544 
   545 
   546 *** System ***
   547 
   548 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   549 
   550 
   551 
   552 New in Isabelle2009-2 (June 2010)
   553 ---------------------------------
   554 
   555 *** General ***
   556 
   557 * Authentic syntax for *all* logical entities (type classes, type
   558 constructors, term constants): provides simple and robust
   559 correspondence between formal entities and concrete syntax.  Within
   560 the parse tree / AST representations, "constants" are decorated by
   561 their category (class, type, const) and spelled out explicitly with
   562 their full internal name.
   563 
   564 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   565 and translations (translation rules and translation functions in ML).
   566 Some hints on upgrading:
   567 
   568   - Many existing uses of 'syntax' and 'translations' can be replaced
   569     by more modern 'type_notation', 'notation' and 'abbreviation',
   570     which are independent of this issue.
   571 
   572   - 'translations' require markup within the AST; the term syntax
   573     provides the following special forms:
   574 
   575       CONST c   -- produces syntax version of constant c from context
   576       XCONST c  -- literally c, checked as constant from context
   577       c         -- literally c, if declared by 'syntax'
   578 
   579     Plain identifiers are treated as AST variables -- occasionally the
   580     system indicates accidental variables via the error "rhs contains
   581     extra variables".
   582 
   583     Type classes and type constructors are marked according to their
   584     concrete syntax.  Some old translations rules need to be written
   585     for the "type" category, using type constructor application
   586     instead of pseudo-term application of the default category
   587     "logic".
   588 
   589   - 'parse_translation' etc. in ML may use the following
   590     antiquotations:
   591 
   592       @{class_syntax c}   -- type class c within parse tree / AST
   593       @{term_syntax c}    -- type constructor c within parse tree / AST
   594       @{const_syntax c}   -- ML version of "CONST c" above
   595       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   596 
   597   - Literal types within 'typed_print_translations', i.e. those *not*
   598     represented as pseudo-terms are represented verbatim.  Use @{class
   599     c} or @{type_name c} here instead of the above syntax
   600     antiquotations.
   601 
   602 Note that old non-authentic syntax was based on unqualified base
   603 names, so all of the above "constant" names would coincide.  Recall
   604 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   605 diagnose syntax problems.
   606 
   607 * Type constructors admit general mixfix syntax, not just infix.
   608 
   609 * Concrete syntax may be attached to local entities without a proof
   610 body, too.  This works via regular mixfix annotations for 'fix',
   611 'def', 'obtain' etc. or via the explicit 'write' command, which is
   612 similar to the 'notation' command in theory specifications.
   613 
   614 * Discontinued unnamed infix syntax (legacy feature for many years) --
   615 need to specify constant name and syntax separately.  Internal ML
   616 datatype constructors have been renamed from InfixName to Infix etc.
   617 Minor INCOMPATIBILITY.
   618 
   619 * Schematic theorem statements need to be explicitly markup as such,
   620 via commands 'schematic_lemma', 'schematic_theorem',
   621 'schematic_corollary'.  Thus the relevance of the proof is made
   622 syntactically clear, which impacts performance in a parallel or
   623 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   624 
   625 * Use of cumulative prems via "!" in some proof methods has been
   626 discontinued (old legacy feature).
   627 
   628 * References 'trace_simp' and 'debug_simp' have been replaced by
   629 configuration options stored in the context. Enabling tracing (the
   630 case of debugging is similar) in proofs works via
   631 
   632   using [[trace_simp = true]]
   633 
   634 Tracing is then active for all invocations of the simplifier in
   635 subsequent goal refinement steps. Tracing may also still be enabled or
   636 disabled via the ProofGeneral settings menu.
   637 
   638 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   639 'hide_fact' replace the former 'hide' KIND command.  Minor
   640 INCOMPATIBILITY.
   641 
   642 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   643 more efficient than combinations with -q1 or -q2.
   644 
   645 
   646 *** Pure ***
   647 
   648 * Proofterms record type-class reasoning explicitly, using the
   649 "unconstrain" operation internally.  This eliminates all sort
   650 constraints from a theorem and proof, introducing explicit
   651 OFCLASS-premises.  On the proof term level, this operation is
   652 automatically applied at theorem boundaries, such that closed proofs
   653 are always free of sort constraints.  INCOMPATIBILITY for tools that
   654 inspect proof terms.
   655 
   656 * Local theory specifications may depend on extra type variables that
   657 are not present in the result type -- arguments TYPE('a) :: 'a itself
   658 are added internally.  For example:
   659 
   660   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   661 
   662 * Predicates of locales introduced by classes carry a mandatory
   663 "class" prefix.  INCOMPATIBILITY.
   664 
   665 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   666 
   667 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   668 'class' instead.
   669 
   670 * Command 'code_reflect' allows to incorporate generated ML code into
   671 runtime environment; replaces immature code_datatype antiquotation.
   672 INCOMPATIBILITY.
   673 
   674 * Code generator: simple concept for abstract datatypes obeying
   675 invariants.
   676 
   677 * Code generator: details of internal data cache have no impact on the
   678 user space functionality any longer.
   679 
   680 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   681 subgoals.  This is more appropriate for interpretations with 'where'.
   682 INCOMPATIBILITY.
   683 
   684 * Command 'example_proof' opens an empty proof body.  This allows to
   685 experiment with Isar, without producing any persistent result.
   686 
   687 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   688 within a local theory context, with explicit checking of the
   689 constructors involved (in contrast to the raw 'syntax' versions).
   690 
   691 * Commands 'types' and 'typedecl' now work within a local theory
   692 context -- without introducing dependencies on parameters or
   693 assumptions, which is not possible in Isabelle/Pure.
   694 
   695 * Command 'defaultsort' has been renamed to 'default_sort', it works
   696 within a local theory context.  Minor INCOMPATIBILITY.
   697 
   698 
   699 *** HOL ***
   700 
   701 * Command 'typedef' now works within a local theory context -- without
   702 introducing dependencies on parameters or assumptions, which is not
   703 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   704 contain multiple interpretations of local typedefs (with different
   705 non-emptiness proofs), even in a global theory context.
   706 
   707 * New package for quotient types.  Commands 'quotient_type' and
   708 'quotient_definition' may be used for defining types and constants by
   709 quotient constructions.  An example is the type of integers created by
   710 quotienting pairs of natural numbers:
   711 
   712   fun
   713     intrel :: "(nat * nat) => (nat * nat) => bool"
   714   where
   715     "intrel (x, y) (u, v) = (x + v = u + y)"
   716 
   717   quotient_type int = "nat * nat" / intrel
   718     by (auto simp add: equivp_def expand_fun_eq)
   719 
   720   quotient_definition
   721     "0::int" is "(0::nat, 0::nat)"
   722 
   723 The method "lifting" can be used to lift of theorems from the
   724 underlying "raw" type to the quotient type.  The example
   725 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   726 construction and provides a reasoning infrastructure for finite sets.
   727 
   728 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   729 clash with new theory Quotient in Main HOL.
   730 
   731 * Moved the SMT binding into the main HOL session, eliminating
   732 separate HOL-SMT session.
   733 
   734 * List membership infix mem operation is only an input abbreviation.
   735 INCOMPATIBILITY.
   736 
   737 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   738 for future developements; former Library/Word.thy is still present in
   739 the AFP entry RSAPPS.
   740 
   741 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   742 longer shadowed.  INCOMPATIBILITY.
   743 
   744 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   745 INCOMPATIBILITY.
   746 
   747 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   748 INCOMPATIBILITY.
   749 
   750 * Dropped normalizing_semiring etc; use the facts in semiring classes
   751 instead.  INCOMPATIBILITY.
   752 
   753 * Dropped several real-specific versions of lemmas about floor and
   754 ceiling; use the generic lemmas from theory "Archimedean_Field"
   755 instead.  INCOMPATIBILITY.
   756 
   757   floor_number_of_eq         ~> floor_number_of
   758   le_floor_eq_number_of      ~> number_of_le_floor
   759   le_floor_eq_zero           ~> zero_le_floor
   760   le_floor_eq_one            ~> one_le_floor
   761   floor_less_eq_number_of    ~> floor_less_number_of
   762   floor_less_eq_zero         ~> floor_less_zero
   763   floor_less_eq_one          ~> floor_less_one
   764   less_floor_eq_number_of    ~> number_of_less_floor
   765   less_floor_eq_zero         ~> zero_less_floor
   766   less_floor_eq_one          ~> one_less_floor
   767   floor_le_eq_number_of      ~> floor_le_number_of
   768   floor_le_eq_zero           ~> floor_le_zero
   769   floor_le_eq_one            ~> floor_le_one
   770   floor_subtract_number_of   ~> floor_diff_number_of
   771   floor_subtract_one         ~> floor_diff_one
   772   ceiling_number_of_eq       ~> ceiling_number_of
   773   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   774   ceiling_le_zero_eq         ~> ceiling_le_zero
   775   ceiling_le_eq_one          ~> ceiling_le_one
   776   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   777   less_ceiling_eq_zero       ~> zero_less_ceiling
   778   less_ceiling_eq_one        ~> one_less_ceiling
   779   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   780   ceiling_less_eq_zero       ~> ceiling_less_zero
   781   ceiling_less_eq_one        ~> ceiling_less_one
   782   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   783   le_ceiling_eq_zero         ~> zero_le_ceiling
   784   le_ceiling_eq_one          ~> one_le_ceiling
   785   ceiling_subtract_number_of ~> ceiling_diff_number_of
   786   ceiling_subtract_one       ~> ceiling_diff_one
   787 
   788 * Theory "Finite_Set": various folding_XXX locales facilitate the
   789 application of the various fold combinators on finite sets.
   790 
   791 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   792 provides abstract red-black tree type which is backed by "RBT_Impl" as
   793 implementation.  INCOMPATIBILTY.
   794 
   795 * Theory Library/Coinductive_List has been removed -- superseded by
   796 AFP/thys/Coinductive.
   797 
   798 * Theory PReal, including the type "preal" and related operations, has
   799 been removed.  INCOMPATIBILITY.
   800 
   801 * Real: new development using Cauchy Sequences.
   802 
   803 * Split off theory "Big_Operators" containing setsum, setprod,
   804 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   805 
   806 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   807 "Int" etc.  INCOMPATIBILITY.
   808 
   809 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   810 
   811 * New set of rules "ac_simps" provides combined assoc / commute
   812 rewrites for all interpretations of the appropriate generic locales.
   813 
   814 * Renamed theory "OrderedGroup" to "Groups" and split theory
   815 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   816 appropriate and more consistent names suitable for name prefixes
   817 within the HOL theories.  INCOMPATIBILITY.
   818 
   819 * Some generic constants have been put to appropriate theories:
   820   - less_eq, less: Orderings
   821   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   822   - inverse, divide: Rings
   823 INCOMPATIBILITY.
   824 
   825 * More consistent naming of type classes involving orderings (and
   826 lattices):
   827 
   828     lower_semilattice                   ~> semilattice_inf
   829     upper_semilattice                   ~> semilattice_sup
   830 
   831     dense_linear_order                  ~> dense_linorder
   832 
   833     pordered_ab_group_add               ~> ordered_ab_group_add
   834     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   835     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   836     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   837     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   838     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   839     pordered_cancel_semiring            ~> ordered_cancel_semiring
   840     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   841     pordered_comm_ring                  ~> ordered_comm_ring
   842     pordered_comm_semiring              ~> ordered_comm_semiring
   843     pordered_ring                       ~> ordered_ring
   844     pordered_ring_abs                   ~> ordered_ring_abs
   845     pordered_semiring                   ~> ordered_semiring
   846 
   847     ordered_ab_group_add                ~> linordered_ab_group_add
   848     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   849     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   850     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   851     ordered_field                       ~> linordered_field
   852     ordered_field_no_lb                 ~> linordered_field_no_lb
   853     ordered_field_no_ub                 ~> linordered_field_no_ub
   854     ordered_field_dense_linear_order    ~> dense_linordered_field
   855     ordered_idom                        ~> linordered_idom
   856     ordered_ring                        ~> linordered_ring
   857     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   858     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   859     ordered_ring_strict                 ~> linordered_ring_strict
   860     ordered_semidom                     ~> linordered_semidom
   861     ordered_semiring                    ~> linordered_semiring
   862     ordered_semiring_1                  ~> linordered_semiring_1
   863     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   864     ordered_semiring_strict             ~> linordered_semiring_strict
   865 
   866   The following slightly odd type classes have been moved to a
   867   separate theory Library/Lattice_Algebras:
   868 
   869     lordered_ab_group_add               ~> lattice_ab_group_add
   870     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   871     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   872     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   873     lordered_ring                       ~> lattice_ring
   874 
   875 INCOMPATIBILITY.
   876 
   877 * Refined field classes:
   878   - classes division_ring_inverse_zero, field_inverse_zero,
   879     linordered_field_inverse_zero include rule inverse 0 = 0 --
   880     subsumes former division_by_zero class;
   881   - numerous lemmas have been ported from field to division_ring.
   882 INCOMPATIBILITY.
   883 
   884 * Refined algebra theorem collections:
   885   - dropped theorem group group_simps, use algebra_simps instead;
   886   - dropped theorem group ring_simps, use field_simps instead;
   887   - proper theorem collection field_simps subsumes former theorem
   888     groups field_eq_simps and field_simps;
   889   - dropped lemma eq_minus_self_iff which is a duplicate for
   890     equal_neg_zero.
   891 INCOMPATIBILITY.
   892 
   893 * Theory Finite_Set and List: some lemmas have been generalized from
   894 sets to lattices:
   895 
   896   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   897   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   898   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   899   union_Union_fold_union        ~> sup_Sup_fold_sup
   900   Inter_fold_inter              ~> Inf_fold_inf
   901   Union_fold_union              ~> Sup_fold_sup
   902   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   903   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   904   INTER_fold_inter              ~> INFI_fold_inf
   905   UNION_fold_union              ~> SUPR_fold_sup
   906 
   907 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   908 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   909 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   910 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   911 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   912 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   913 
   914 * Reorganized theory Multiset: swapped notation of pointwise and
   915 multiset order:
   916 
   917   - pointwise ordering is instance of class order with standard syntax
   918     <= and <;
   919   - multiset ordering has syntax <=# and <#; partial order properties
   920     are provided by means of interpretation with prefix
   921     multiset_order;
   922   - less duplication, less historical organization of sections,
   923     conversion from associations lists to multisets, rudimentary code
   924     generation;
   925   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   926     if needed.
   927 
   928 Renamed:
   929 
   930   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   931   multi_count_ext  ~>  multiset_ext
   932   diff_union_inverse2  ~>  diff_union_cancelR
   933 
   934 INCOMPATIBILITY.
   935 
   936 * Theory Permutation: replaced local "remove" by List.remove1.
   937 
   938 * Code generation: ML and OCaml code is decorated with signatures.
   939 
   940 * Theory List: added transpose.
   941 
   942 * Library/Nat_Bijection.thy is a collection of bijective functions
   943 between nat and other types, which supersedes the older libraries
   944 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   945 
   946   Constants:
   947   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
   948   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
   949   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
   950   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
   951   Countable.pair_encode           ~> prod_encode
   952   NatIso.prod2nat                 ~> prod_encode
   953   NatIso.nat2prod                 ~> prod_decode
   954   NatIso.sum2nat                  ~> sum_encode
   955   NatIso.nat2sum                  ~> sum_decode
   956   NatIso.list2nat                 ~> list_encode
   957   NatIso.nat2list                 ~> list_decode
   958   NatIso.set2nat                  ~> set_encode
   959   NatIso.nat2set                  ~> set_decode
   960 
   961   Lemmas:
   962   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
   963   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
   964   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
   965   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
   966   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
   967   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
   968   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
   969   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
   970   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
   971   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
   972   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
   973   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
   974   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
   975 
   976 * Sledgehammer:
   977   - Renamed ATP commands:
   978     atp_info     ~> sledgehammer running_atps
   979     atp_kill     ~> sledgehammer kill_atps
   980     atp_messages ~> sledgehammer messages
   981     atp_minimize ~> sledgehammer minimize
   982     print_atps   ~> sledgehammer available_atps
   983     INCOMPATIBILITY.
   984   - Added user's manual ("isabelle doc sledgehammer").
   985   - Added option syntax and "sledgehammer_params" to customize
   986     Sledgehammer's behavior.  See the manual for details.
   987   - Modified the Isar proof reconstruction code so that it produces
   988     direct proofs rather than proofs by contradiction.  (This feature
   989     is still experimental.)
   990   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
   991     full-typed mode.
   992   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
   993 
   994 * Nitpick:
   995   - Added and implemented "binary_ints" and "bits" options.
   996   - Added "std" option and implemented support for nonstandard models.
   997   - Added and implemented "finitize" option to improve the precision
   998     of infinite datatypes based on a monotonicity analysis.
   999   - Added support for quotient types.
  1000   - Added support for "specification" and "ax_specification"
  1001     constructs.
  1002   - Added support for local definitions (for "function" and
  1003     "termination" proofs).
  1004   - Added support for term postprocessors.
  1005   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1006   - Improved efficiency of "destroy_constrs" optimization.
  1007   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1008     record getters.
  1009   - Fixed soundness bug related to higher-order constructors.
  1010   - Fixed soundness bug when "full_descrs" is enabled.
  1011   - Improved precision of set constructs.
  1012   - Added "atoms" option.
  1013   - Added cache to speed up repeated Kodkod invocations on the same
  1014     problems.
  1015   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1016     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1017     "SAT4J_Light".  INCOMPATIBILITY.
  1018   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1019     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1020   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1021 
  1022 * Method "induct" now takes instantiations of the form t, where t is not
  1023   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1024   If this is not intended, t has to be enclosed in parentheses.
  1025   By default, the equalities generated by definitional instantiations
  1026   are pre-simplified, which may cause parameters of inductive cases
  1027   to disappear, or may even delete some of the inductive cases.
  1028   Use "induct (no_simp)" instead of "induct" to restore the old
  1029   behaviour. The (no_simp) option is also understood by the "cases"
  1030   and "nominal_induct" methods, which now perform pre-simplification, too.
  1031   INCOMPATIBILITY.
  1032 
  1033 
  1034 *** HOLCF ***
  1035 
  1036 * Variable names in lemmas generated by the domain package have
  1037 changed; the naming scheme is now consistent with the HOL datatype
  1038 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1039 
  1040 * The domain package no longer defines the function "foo_copy" for
  1041 recursive domain "foo".  The reach lemma is now stated directly in
  1042 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1043 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1044 
  1045 * Most definedness lemmas generated by the domain package (previously
  1046 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1047 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1048 Proofs that used definedness lemmas as intro rules may break,
  1049 potential INCOMPATIBILITY.
  1050 
  1051 * Induction and casedist rules generated by the domain package now
  1052 declare proper case_names (one called "bottom", and one named for each
  1053 constructor).  INCOMPATIBILITY.
  1054 
  1055 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1056 rules are generated for each domain, INCOMPATIBILITY.
  1057 
  1058   foo_bar.reach       ~> foo.reach  bar.reach
  1059   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1060 
  1061 * Some lemmas generated by the domain package have been renamed for
  1062 consistency with the datatype package, INCOMPATIBILITY.
  1063 
  1064   foo.ind        ~> foo.induct
  1065   foo.finite_ind ~> foo.finite_induct
  1066   foo.coind      ~> foo.coinduct
  1067   foo.casedist   ~> foo.exhaust
  1068   foo.exhaust    ~> foo.nchotomy
  1069 
  1070 * For consistency with other definition packages, the fixrec package
  1071 now generates qualified theorem names, INCOMPATIBILITY.
  1072 
  1073   foo_simps  ~> foo.simps
  1074   foo_unfold ~> foo.unfold
  1075   foo_induct ~> foo.induct
  1076 
  1077 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1078 method and internal fixrec proofs now use the default simpset instead.
  1079 INCOMPATIBILITY.
  1080 
  1081 * The "contlub" predicate has been removed.  Proof scripts should use
  1082 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1083 
  1084 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1085 
  1086 * The constants cpair, cfst, and csnd have been removed in favor of
  1087 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1088 
  1089 
  1090 *** ML ***
  1091 
  1092 * Antiquotations for basic formal entities:
  1093 
  1094     @{class NAME}         -- type class
  1095     @{class_syntax NAME}  -- syntax representation of the above
  1096 
  1097     @{type_name NAME}     -- logical type
  1098     @{type_abbrev NAME}   -- type abbreviation
  1099     @{nonterminal NAME}   -- type of concrete syntactic category
  1100     @{type_syntax NAME}   -- syntax representation of any of the above
  1101 
  1102     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1103     @{const_abbrev NAME}  -- abbreviated constant
  1104     @{const_syntax NAME}  -- syntax representation of any of the above
  1105 
  1106 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1107 syntax constant (cf. 'syntax' command).
  1108 
  1109 * Antiquotation @{make_string} inlines a function to print arbitrary
  1110 values similar to the ML toplevel.  The result is compiler dependent
  1111 and may fall back on "?" in certain situations.
  1112 
  1113 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1114 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1115 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1116 not work with the asynchronous Isar document model.
  1117 
  1118 * Configuration options now admit dynamic default values, depending on
  1119 the context or even global references.
  1120 
  1121 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1122 uses an efficient external library if available (for Poly/ML).
  1123 
  1124 * Renamed some important ML structures, while keeping the old names
  1125 for some time as aliases within the structure Legacy:
  1126 
  1127   OuterKeyword  ~>  Keyword
  1128   OuterLex      ~>  Token
  1129   OuterParse    ~>  Parse
  1130   OuterSyntax   ~>  Outer_Syntax
  1131   PrintMode     ~>  Print_Mode
  1132   SpecParse     ~>  Parse_Spec
  1133   ThyInfo       ~>  Thy_Info
  1134   ThyLoad       ~>  Thy_Load
  1135   ThyOutput     ~>  Thy_Output
  1136   TypeInfer     ~>  Type_Infer
  1137 
  1138 Note that "open Legacy" simplifies porting of sources, but forgetting
  1139 to remove it again will complicate porting again in the future.
  1140 
  1141 * Most operations that refer to a global context are named
  1142 accordingly, e.g. Simplifier.global_context or
  1143 ProofContext.init_global.  There are some situations where a global
  1144 context actually works, but under normal circumstances one needs to
  1145 pass the proper local context through the code!
  1146 
  1147 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1148 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1149 Pretty.pp argument to merge, which is absent in the standard
  1150 Theory_Data version.
  1151 
  1152 * Sorts.certify_sort and derived "cert" operations for types and terms
  1153 no longer minimize sorts.  Thus certification at the boundary of the
  1154 inference kernel becomes invariant under addition of class relations,
  1155 which is an important monotonicity principle.  Sorts are now minimized
  1156 in the syntax layer only, at the boundary between the end-user and the
  1157 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1158 explicitly in rare situations.
  1159 
  1160 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1161 emphasize that this is in no way a standard operation.
  1162 INCOMPATIBILITY.
  1163 
  1164 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1165 usual for resolution.  Rare INCOMPATIBILITY.
  1166 
  1167 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1168 to emphasize that these only work in a global situation (which is
  1169 quite rare).
  1170 
  1171 * Curried take and drop in library.ML; negative length is interpreted
  1172 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1173 
  1174 * Proof terms: type substitutions on proof constants now use canonical
  1175 order of type variables.  INCOMPATIBILITY for tools working with proof
  1176 terms.
  1177 
  1178 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1179 may no longer carry premises.  User-level specifications are
  1180 transformed accordingly by Thm.add_axiom/add_def.
  1181 
  1182 
  1183 *** System ***
  1184 
  1185 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1186 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1187 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1188 
  1189 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1190 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1191 respectively.
  1192 
  1193 * Old lib/scripts/polyml-platform is superseded by the
  1194 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1195 variant, even on a 64 bit machine.  The following example setting
  1196 prefers 64 bit if available:
  1197 
  1198   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1199 
  1200 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1201 Isabelle/Scala layer for advanced prover interaction and integration.
  1202 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1203 component.
  1204 
  1205 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1206 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1207 similar to the default assignment of the document preparation system
  1208 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1209 provides some operations for direct access to the font without asking
  1210 the user for manual installation.
  1211 
  1212 
  1213 
  1214 New in Isabelle2009-1 (December 2009)
  1215 -------------------------------------
  1216 
  1217 *** General ***
  1218 
  1219 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1220 one backslash should be used, even in ML sources.
  1221 
  1222 
  1223 *** Pure ***
  1224 
  1225 * Locale interpretation propagates mixins along the locale hierarchy.
  1226 The currently only available mixins are the equations used to map
  1227 local definitions to terms of the target domain of an interpretation.
  1228 
  1229 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1230 loc" to print all interpretations of locale "loc" in the theory.
  1231 Interpretations in proofs are not shown.
  1232 
  1233 * Thoroughly revised locales tutorial.  New section on conditional
  1234 interpretation.
  1235 
  1236 * On instantiation of classes, remaining undefined class parameters
  1237 are formally declared.  INCOMPATIBILITY.
  1238 
  1239 
  1240 *** Document preparation ***
  1241 
  1242 * New generalized style concept for printing terms: @{foo (style) ...}
  1243 instead of @{foo_style style ...}  (old form is still retained for
  1244 backward compatibility).  Styles can be also applied for
  1245 antiquotations prop, term_type and typeof.
  1246 
  1247 
  1248 *** HOL ***
  1249 
  1250 * New proof method "smt" for a combination of first-order logic with
  1251 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1252 fixed-size bitvectors; there is also basic support for higher-order
  1253 features (esp. lambda abstractions).  It is an incomplete decision
  1254 procedure based on external SMT solvers using the oracle mechanism;
  1255 for the SMT solver Z3, this method is proof-producing.  Certificates
  1256 are provided to avoid calling the external solvers solely for
  1257 re-checking proofs.  Due to a remote SMT service there is no need for
  1258 installing SMT solvers locally.  See src/HOL/SMT.
  1259 
  1260 * New commands to load and prove verification conditions generated by
  1261 the Boogie program verifier or derived systems (e.g. the Verifying C
  1262 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1263 
  1264 * New counterexample generator tool 'nitpick' based on the Kodkod
  1265 relational model finder.  See src/HOL/Tools/Nitpick and
  1266 src/HOL/Nitpick_Examples.
  1267 
  1268 * New commands 'code_pred' and 'values' to invoke the predicate
  1269 compiler and to enumerate values of inductive predicates.
  1270 
  1271 * A tabled implementation of the reflexive transitive closure.
  1272 
  1273 * New implementation of quickcheck uses generic code generator;
  1274 default generators are provided for all suitable HOL types, records
  1275 and datatypes.  Old quickcheck can be re-activated importing theory
  1276 Library/SML_Quickcheck.
  1277 
  1278 * New testing tool Mirabelle for automated proof tools.  Applies
  1279 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1280 every proof step in a theory.  To be used in batch mode via the
  1281 "mirabelle" utility.
  1282 
  1283 * New proof method "sos" (sum of squares) for nonlinear real
  1284 arithmetic (originally due to John Harison). It requires theory
  1285 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1286 works well in practice on quantifier-free real arithmetic with +, -,
  1287 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1288 inequalities between polynomials.  It makes use of external
  1289 semidefinite programming solvers.  Method "sos" generates a
  1290 certificate that can be pasted into the proof thus avoiding the need
  1291 to call an external tool every time the proof is checked.  See
  1292 src/HOL/Library/Sum_Of_Squares.
  1293 
  1294 * New method "linarith" invokes existing linear arithmetic decision
  1295 procedure only.
  1296 
  1297 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1298 
  1299 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1300 Causes full type information to be output to the ATPs.  This slows
  1301 ATPs down considerably but eliminates a source of unsound "proofs"
  1302 that fail later.
  1303 
  1304 * New method "metisFT": A version of metis that uses full type
  1305 information in order to avoid failures of proof reconstruction.
  1306 
  1307 * New evaluator "approximate" approximates an real valued term using
  1308 the same method as the approximation method.
  1309 
  1310 * Method "approximate" now supports arithmetic expressions as
  1311 boundaries of intervals and implements interval splitting and Taylor
  1312 series expansion.
  1313 
  1314 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1315 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1316 
  1317 * New theory SupInf of the supremum and infimum operators for sets of
  1318 reals.
  1319 
  1320 * New theory Probability, which contains a development of measure
  1321 theory, eventually leading to Lebesgue integration and probability.
  1322 
  1323 * Extended Multivariate Analysis to include derivation and Brouwer's
  1324 fixpoint theorem.
  1325 
  1326 * Reorganization of number theory, INCOMPATIBILITY:
  1327   - new number theory development for nat and int, in theories Divides
  1328     and GCD as well as in new session Number_Theory
  1329   - some constants and facts now suffixed with _nat and _int
  1330     accordingly
  1331   - former session NumberTheory now named Old_Number_Theory, including
  1332     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1333   - moved theory Pocklington from src/HOL/Library to
  1334     src/HOL/Old_Number_Theory
  1335 
  1336 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1337 lcm of finite and infinite sets. It is shown that they form a complete
  1338 lattice.
  1339 
  1340 * Class semiring_div requires superclass no_zero_divisors and proof of
  1341 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1342 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1343 generalized to class semiring_div, subsuming former theorems
  1344 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1345 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1346 INCOMPATIBILITY.
  1347 
  1348 * Refinements to lattice classes and sets:
  1349   - less default intro/elim rules in locale variant, more default
  1350     intro/elim rules in class variant: more uniformity
  1351   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1352     le_inf_iff
  1353   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1354     sup_aci)
  1355   - renamed ACI to inf_sup_aci
  1356   - new class "boolean_algebra"
  1357   - class "complete_lattice" moved to separate theory
  1358     "Complete_Lattice"; corresponding constants (and abbreviations)
  1359     renamed and with authentic syntax:
  1360     Set.Inf ~>    Complete_Lattice.Inf
  1361     Set.Sup ~>    Complete_Lattice.Sup
  1362     Set.INFI ~>   Complete_Lattice.INFI
  1363     Set.SUPR ~>   Complete_Lattice.SUPR
  1364     Set.Inter ~>  Complete_Lattice.Inter
  1365     Set.Union ~>  Complete_Lattice.Union
  1366     Set.INTER ~>  Complete_Lattice.INTER
  1367     Set.UNION ~>  Complete_Lattice.UNION
  1368   - authentic syntax for
  1369     Set.Pow
  1370     Set.image
  1371   - mere abbreviations:
  1372     Set.empty               (for bot)
  1373     Set.UNIV                (for top)
  1374     Set.inter               (for inf, formerly Set.Int)
  1375     Set.union               (for sup, formerly Set.Un)
  1376     Complete_Lattice.Inter  (for Inf)
  1377     Complete_Lattice.Union  (for Sup)
  1378     Complete_Lattice.INTER  (for INFI)
  1379     Complete_Lattice.UNION  (for SUPR)
  1380   - object-logic definitions as far as appropriate
  1381 
  1382 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1383 Un_subset_iff are explicitly deleted as default simp rules; then also
  1384 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1385 deleted to achieve the desired effect.
  1386 
  1387 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1388 rules by default any longer; the same applies to min_max.inf_absorb1
  1389 etc.  INCOMPATIBILITY.
  1390 
  1391 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1392 pred_set_conv by default.  INCOMPATIBILITY.
  1393 
  1394 * Power operations on relations and functions are now one dedicated
  1395 constant "compow" with infix syntax "^^".  Power operation on
  1396 multiplicative monoids retains syntax "^" and is now defined generic
  1397 in class power.  INCOMPATIBILITY.
  1398 
  1399 * Relation composition "R O S" now has a more standard argument order:
  1400 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1401 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1402 break, since the O_assoc rule was not rewritten like this.  Fix using
  1403 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1404 
  1405 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1406 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1407 INCOMPATIBILITY.
  1408 
  1409 * Most rules produced by inductive and datatype package have mandatory
  1410 prefixes.  INCOMPATIBILITY.
  1411 
  1412 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1413 the attribute of the same name.  Each of the theorems in the list
  1414 DERIV_intros assumes composition with an additional function and
  1415 matches a variable to the derivative, which has to be solved by the
  1416 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1417 of most elementary terms.  Former Maclauren.DERIV_tac and
  1418 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1419 INCOMPATIBILITY.
  1420 
  1421 * Code generator attributes follow the usual underscore convention:
  1422     code_unfold     replaces    code unfold
  1423     code_post       replaces    code post
  1424     etc.
  1425   INCOMPATIBILITY.
  1426 
  1427 * Renamed methods:
  1428     sizechange -> size_change
  1429     induct_scheme -> induction_schema
  1430   INCOMPATIBILITY.
  1431 
  1432 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1433 INCOMPATIBILITY, use "undefined" directly.
  1434 
  1435 * Renamed theorems:
  1436     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1437     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1438     Suc_plus1 -> Suc_eq_plus1
  1439     *anti_sym -> *antisym*
  1440     vector_less_eq_def -> vector_le_def
  1441   INCOMPATIBILITY.
  1442 
  1443 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1444 INCOMPATIBILITY.
  1445 
  1446 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1447 INCOMPATIBILITY.
  1448 
  1449 
  1450 *** HOLCF ***
  1451 
  1452 * Theory Representable defines a class "rep" of domains that are
  1453 representable (via an ep-pair) in the universal domain type "udom".
  1454 Instances are provided for all type constructors defined in HOLCF.
  1455 
  1456 * The 'new_domain' command is a purely definitional version of the
  1457 domain package, for representable domains.  Syntax is identical to the
  1458 old domain package.  The 'new_domain' package also supports indirect
  1459 recursion using previously-defined type constructors.  See
  1460 src/HOLCF/ex/New_Domain.thy for examples.
  1461 
  1462 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1463 on the left-hand side of an equation, and then performs
  1464 simplification.  Rewriting is done using rules declared with the
  1465 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1466 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1467 
  1468 * The pattern-match compiler in 'fixrec' can now handle constructors
  1469 with HOL function types.  Pattern-match combinators for the Pair
  1470 constructor are pre-configured.
  1471 
  1472 * The 'fixrec' package now produces better fixed-point induction rules
  1473 for mutually-recursive definitions:  Induction rules have conclusions
  1474 of the form "P foo bar" instead of "P <foo, bar>".
  1475 
  1476 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1477 been renamed to "below".  The name "below" now replaces "less" in many
  1478 theorem names.  (Legacy theorem names using "less" are still supported
  1479 as well.)
  1480 
  1481 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1482 patterns can be used to generate strictness rules, or to make
  1483 functions more strict (much like the bang-patterns supported by the
  1484 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1485 examples.
  1486 
  1487 
  1488 *** ML ***
  1489 
  1490 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1491 errors and run-time exceptions, including detailed source positions.
  1492 
  1493 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1494 identified entries, with some additional information such as source
  1495 position, logical grouping etc.
  1496 
  1497 * Theory and context data is now introduced by the simplified and
  1498 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1499 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1500 copy operation) is still available for some time.
  1501 
  1502 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1503 provides a high-level programming interface to synchronized state
  1504 variables with atomic update.  This works via pure function
  1505 application within a critical section -- its runtime should be as
  1506 short as possible; beware of deadlocks if critical code is nested,
  1507 either directly or indirectly via other synchronized variables!
  1508 
  1509 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1510 wraps raw ML references, explicitly indicating their non-thread-safe
  1511 behaviour.  The Isar toplevel keeps this structure open, to
  1512 accommodate Proof General as well as quick and dirty interactive
  1513 experiments with references.
  1514 
  1515 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1516 parallel tactical reasoning.
  1517 
  1518 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1519 are similar to SUBPROOF, but are slightly more flexible: only the
  1520 specified parts of the subgoal are imported into the context, and the
  1521 body tactic may introduce new subgoals and schematic variables.
  1522 
  1523 * Old tactical METAHYPS, which does not observe the proof context, has
  1524 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1525 or Subgoal.FOCUS etc.
  1526 
  1527 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1528 functors have their own ML name space there is no point to mark them
  1529 separately.)  Minor INCOMPATIBILITY.
  1530 
  1531 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1532 
  1533 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1534 INCOMPATIBILITY.
  1535 
  1536 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1537 mode, which avoids critical setmp.
  1538 
  1539 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1540 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1541 Attrib/Method.setup introduced in Isabelle2009.
  1542 
  1543 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1544 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1545 last resort.  INCOMPATIBILITY.
  1546 
  1547 * Display.pretty_thm now requires a proper context (cf. former
  1548 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1549 or even Display.pretty_thm_without_context as last resort.
  1550 INCOMPATIBILITY.
  1551 
  1552 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1553 Syntax.pretty_typ/term directly, preferably with proper context
  1554 instead of global theory.
  1555 
  1556 
  1557 *** System ***
  1558 
  1559 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1560 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1561 usedir option -q.
  1562 
  1563 * Support for additional "Isabelle components" via etc/components, see
  1564 also the system manual.
  1565 
  1566 * The isabelle makeall tool now operates on all components with
  1567 IsaMakefile, not just hardwired "logics".
  1568 
  1569 * Removed "compress" option from isabelle-process and isabelle usedir;
  1570 this is always enabled.
  1571 
  1572 * Discontinued support for Poly/ML 4.x versions.
  1573 
  1574 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1575 on a given logic image.  This requires the lighttpd webserver and is
  1576 currently supported on Linux only.
  1577 
  1578 
  1579 
  1580 New in Isabelle2009 (April 2009)
  1581 --------------------------------
  1582 
  1583 *** General ***
  1584 
  1585 * Simplified main Isabelle executables, with less surprises on
  1586 case-insensitive file-systems (such as Mac OS).
  1587 
  1588   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1589     "isatool."
  1590 
  1591   - The former "isabelle" alias for "isabelle-process" has been
  1592     removed (should rarely occur to regular users).
  1593 
  1594   - The former "isabelle-interface" and its alias "Isabelle" have been
  1595     removed (interfaces are now regular Isabelle tools).
  1596 
  1597 Within scripts and make files, the Isabelle environment variables
  1598 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1599 respectively.  (The latter are still available as legacy feature.)
  1600 
  1601 The old isabelle-interface wrapper could react in confusing ways if
  1602 the interface was uninstalled or changed otherwise.  Individual
  1603 interface tool configuration is now more explicit, see also the
  1604 Isabelle system manual.  In particular, Proof General is now available
  1605 via "isabelle emacs".
  1606 
  1607 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1608 purge installed copies of Isabelle executables and re-run "isabelle
  1609 install -p ...", or use symlinks.
  1610 
  1611 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1612 old ~/isabelle, which was slightly non-standard and apt to cause
  1613 surprises on case-insensitive file-systems (such as Mac OS).
  1614 
  1615 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1616 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1617 care is required when using older releases of Isabelle.  Note that
  1618 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1619 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1620 
  1621 * Proofs of fully specified statements are run in parallel on
  1622 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1623 a regular 4-core machine, if the initial heap space is made reasonably
  1624 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1625 
  1626 * The main reference manuals ("isar-ref", "implementation", and
  1627 "system") have been updated and extended.  Formally checked references
  1628 as hyperlinks are now available uniformly.
  1629 
  1630 
  1631 *** Pure ***
  1632 
  1633 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1634 respects.  The most important changes are listed below.  See the
  1635 Tutorial on Locales ("locales" manual) for details.
  1636 
  1637 - In locale expressions, instantiation replaces renaming.  Parameters
  1638 must be declared in a for clause.  To aid compatibility with previous
  1639 parameter inheritance, in locale declarations, parameters that are not
  1640 'touched' (instantiation position "_" or omitted) are implicitly added
  1641 with their syntax at the beginning of the for clause.
  1642 
  1643 - Syntax from abbreviations and definitions in locales is available in
  1644 locale expressions and context elements.  The latter is particularly
  1645 useful in locale declarations.
  1646 
  1647 - More flexible mechanisms to qualify names generated by locale
  1648 expressions.  Qualifiers (prefixes) may be specified in locale
  1649 expressions, and can be marked as mandatory (syntax: "name!:") or
  1650 optional (syntax "name?:").  The default depends for plain "name:"
  1651 depends on the situation where a locale expression is used: in
  1652 commands 'locale' and 'sublocale' prefixes are optional, in
  1653 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1654 implicit qualifiers derived from the parameter names of a locale are
  1655 no longer generated.
  1656 
  1657 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1658 instantiation clause in "interpretation" and "interpret" (square
  1659 brackets) is no longer available.  Use locale expressions.
  1660 
  1661 - When converting proof scripts, mandatory qualifiers in
  1662 'interpretation' and 'interpret' should be retained by default, even
  1663 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1664 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1665 in locale expressions range over a single locale instance only.
  1666 
  1667 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1668 In existing theorem specifications replace the includes element by the
  1669 respective context elements of the included locale, omitting those
  1670 that are already present in the theorem specification.  Multiple
  1671 assume elements of a locale should be replaced by a single one
  1672 involving the locale predicate.  In the proof body, declarations (most
  1673 notably theorems) may be regained by interpreting the respective
  1674 locales in the proof context as required (command "interpret").
  1675 
  1676 If using "includes" in replacement of a target solely because the
  1677 parameter types in the theorem are not as general as in the target,
  1678 consider declaring a new locale with additional type constraints on
  1679 the parameters (context element "constrains").
  1680 
  1681 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1682 
  1683 - Locale interpretation commands no longer attempt to simplify goal.
  1684 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1685 methods intro_locales and unfold_locales to clarify.
  1686 
  1687 - Locale interpretation commands no longer accept interpretation
  1688 attributes.  INCOMPATIBILITY.
  1689 
  1690 * Class declaration: so-called "base sort" must not be given in import
  1691 list any longer, but is inferred from the specification.  Particularly
  1692 in HOL, write
  1693 
  1694     class foo = ...
  1695 
  1696 instead of
  1697 
  1698     class foo = type + ...
  1699 
  1700 * Class target: global versions of theorems stemming do not carry a
  1701 parameter prefix any longer.  INCOMPATIBILITY.
  1702 
  1703 * Class 'instance' command no longer accepts attached definitions.
  1704 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1705 
  1706 * Recovered hiding of consts, which was accidentally broken in
  1707 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1708 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1709 
  1710 * Slightly more coherent Pure syntax, with updated documentation in
  1711 isar-ref manual.  Removed locales meta_term_syntax and
  1712 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1713 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1714 directly in regular applications.
  1715 
  1716 * There is a new syntactic category "float_const" for signed decimal
  1717 fractions (e.g. 123.45 or -123.45).
  1718 
  1719 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1720 interface with 'setup' command instead.
  1721 
  1722 * Command 'local_setup' is similar to 'setup', but operates on a local
  1723 theory context.
  1724 
  1725 * The 'axiomatization' command now only works within a global theory
  1726 context.  INCOMPATIBILITY.
  1727 
  1728 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1729 hypotheses.  Sorts required in the course of reasoning need to be
  1730 covered by the constraints in the initial statement, completed by the
  1731 type instance information of the background theory.  Non-trivial sort
  1732 hypotheses, which rarely occur in practice, may be specified via
  1733 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1734 
  1735   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1736 
  1737 The result contains an implicit sort hypotheses as before --
  1738 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1739 normalization.
  1740 
  1741 * Generalized Isar history, with support for linear undo, direct state
  1742 addressing etc.
  1743 
  1744 * Changed defaults for unify configuration options:
  1745 
  1746   unify_trace_bound = 50 (formerly 25)
  1747   unify_search_bound = 60 (formerly 30)
  1748 
  1749 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1750 
  1751   a) On theory merge, the last set of code equations for a particular
  1752      constant is taken (in accordance with the policy applied by other
  1753      parts of the code generator framework).
  1754 
  1755   b) Code equations stemming from explicit declarations (e.g. code
  1756      attribute) gain priority over default code equations stemming
  1757      from definition, primrec, fun etc.
  1758 
  1759 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1760 
  1761 * Unified theorem tables for both code generators.  Thus [code
  1762 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1763 
  1764 * Command 'find_consts' searches for constants based on type and name
  1765 patterns, e.g.
  1766 
  1767     find_consts "_ => bool"
  1768 
  1769 By default, matching is against subtypes, but it may be restricted to
  1770 the whole type.  Searching by name is possible.  Multiple queries are
  1771 conjunctive and queries may be negated by prefixing them with a
  1772 hyphen:
  1773 
  1774     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1775 
  1776 * New 'find_theorems' criterion "solves" matches theorems that
  1777 directly solve the current goal (modulo higher-order unification).
  1778 
  1779 * Auto solve feature for main theorem statements: whenever a new goal
  1780 is stated, "find_theorems solves" is called; any theorems that could
  1781 solve the lemma directly are listed as part of the goal state.
  1782 Cf. associated options in Proof General Isabelle settings menu,
  1783 enabled by default, with reasonable timeout for pathological cases of
  1784 higher-order unification.
  1785 
  1786 
  1787 *** Document preparation ***
  1788 
  1789 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1790 demanding keyword 'by' and supporting the full method expression
  1791 syntax just like the Isar command 'by'.
  1792 
  1793 
  1794 *** HOL ***
  1795 
  1796 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1797 points Main and Complex_Main remain as before.
  1798 
  1799 * Logic image HOL-Plain provides a minimal HOL with the most important
  1800 tools available (inductive, datatype, primrec, ...).  This facilitates
  1801 experimentation and tool development.  Note that user applications
  1802 (and library theories) should never refer to anything below theory
  1803 Main, as before.
  1804 
  1805 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1806 experimentation due to shorter build times.
  1807 
  1808 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1809 were previously part of former HOL-Complex.  Entry point Hyperreal
  1810 remains valid, but theories formerly using Complex_Main should now use
  1811 new entry point Hypercomplex.
  1812 
  1813 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1814 Posix processes.  Avoids potentially expensive forking of the ML
  1815 process.  New thread-based implementation also works on non-Unix
  1816 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1817 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1818 commands are covered in the isar-ref manual.
  1819 
  1820 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1821 sledgehammer without local ATP installation (Vampire etc.). Other
  1822 provers may be included via suitable ML wrappers, see also
  1823 src/HOL/ATP_Linkup.thy.
  1824 
  1825 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1826 menu.
  1827 
  1828 * The metis method no longer fails because the theorem is too trivial
  1829 (contains the empty clause).
  1830 
  1831 * The metis method now fails in the usual manner, rather than raising
  1832 an exception, if it determines that it cannot prove the theorem.
  1833 
  1834 * Method "coherent" implements a prover for coherent logic (see also
  1835 src/Tools/coherent.ML).
  1836 
  1837 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1838 "undefined" is the right choice to replace "arbitrary", though
  1839 logically there is no difference.  INCOMPATIBILITY.
  1840 
  1841 * Command "value" now integrates different evaluation mechanisms.  The
  1842 result of the first successful evaluation mechanism is printed.  In
  1843 square brackets a particular named evaluation mechanisms may be
  1844 specified (currently, [SML], [code] or [nbe]).  See further
  1845 src/HOL/ex/Eval_Examples.thy.
  1846 
  1847 * Normalization by evaluation now allows non-leftlinear equations.
  1848 Declare with attribute [code nbe].
  1849 
  1850 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1851 as the structured Isar versions "cases" and "induct", cf. the
  1852 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1853 are now presented as a list of individual projections
  1854 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1855 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1856 rare situations a different rule is selected --- notably nested tuple
  1857 elimination instead of former prod.exhaust: use explicit (case_tac t
  1858 rule: prod.exhaust) here.
  1859 
  1860 * Attributes "cases", "induct", "coinduct" support "del" option.
  1861 
  1862 * Removed fact "case_split_thm", which duplicates "case_split".
  1863 
  1864 * The option datatype has been moved to a new theory Option.  Renamed
  1865 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1866 
  1867 * New predicate "strict_mono" classifies strict functions on partial
  1868 orders.  With strict functions on linear orders, reasoning about
  1869 (in)equalities is facilitated by theorems "strict_mono_eq",
  1870 "strict_mono_less_eq" and "strict_mono_less".
  1871 
  1872 * Some set operations are now proper qualified constants with
  1873 authentic syntax.  INCOMPATIBILITY:
  1874 
  1875     op Int ~>   Set.Int
  1876     op Un ~>    Set.Un
  1877     INTER ~>    Set.INTER
  1878     UNION ~>    Set.UNION
  1879     Inter ~>    Set.Inter
  1880     Union ~>    Set.Union
  1881     {} ~>       Set.empty
  1882     UNIV ~>     Set.UNIV
  1883 
  1884 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1885 theory Set.
  1886 
  1887 * Auxiliary class "itself" has disappeared -- classes without any
  1888 parameter are treated as expected by the 'class' command.
  1889 
  1890 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1891 
  1892 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1893 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1894 
  1895 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1896 method "approximation".  It proves formulas on real values by using
  1897 interval arithmetic.  In the formulas are also the transcendental
  1898 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1899 allowed. For examples see
  1900 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1901 
  1902 * Theory "Reflection" now resides in HOL/Library.
  1903 
  1904 * Entry point to Word library now simply named "Word".
  1905 INCOMPATIBILITY.
  1906 
  1907 * Made source layout more coherent with logical distribution
  1908 structure:
  1909 
  1910     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1911     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1912     src/HOL/Library/GCD.thy ~> src/HOL/
  1913     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1914     src/HOL/Library/Parity.thy ~> src/HOL/
  1915     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1916     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1917     src/HOL/Real/Lubs.thy ~> src/HOL/
  1918     src/HOL/Real/PReal.thy ~> src/HOL/
  1919     src/HOL/Real/Rational.thy ~> src/HOL/
  1920     src/HOL/Real/RComplete.thy ~> src/HOL/
  1921     src/HOL/Real/RealDef.thy ~> src/HOL/
  1922     src/HOL/Real/RealPow.thy ~> src/HOL/
  1923     src/HOL/Real/Real.thy ~> src/HOL/
  1924     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1925     src/HOL/Complex/Complex.thy ~> src/HOL/
  1926     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1927     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1928     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1929     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1930     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1931     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1932     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1933     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1934     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1935     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1936     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1937     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1938     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1939     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1940     src/HOL/Real/Float ~> src/HOL/Library/
  1941     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1942     src/HOL/Real/RealVector.thy ~> src/HOL/
  1943 
  1944     src/HOL/arith_data.ML ~> src/HOL/Tools
  1945     src/HOL/hologic.ML ~> src/HOL/Tools
  1946     src/HOL/simpdata.ML ~> src/HOL/Tools
  1947     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  1948     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  1949     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  1950     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  1951     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  1952     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  1953     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  1954 
  1955     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  1956     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  1957     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  1958     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  1959     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  1960     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  1961 
  1962 * If methods "eval" and "evaluation" encounter a structured proof
  1963 state with !!/==>, only the conclusion is evaluated to True (if
  1964 possible), avoiding strange error messages.
  1965 
  1966 * Method "sizechange" automates termination proofs using (a
  1967 modification of) the size-change principle.  Requires SAT solver.  See
  1968 src/HOL/ex/Termination.thy for examples.
  1969 
  1970 * Simplifier: simproc for let expressions now unfolds if bound
  1971 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  1972 
  1973 * Method "arith": Linear arithmetic now ignores all inequalities when
  1974 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  1975 
  1976 * New attribute "arith" for facts that should always be used
  1977 automatically by arithmetic. It is intended to be used locally in
  1978 proofs, e.g.
  1979 
  1980   assumes [arith]: "x > 0"
  1981 
  1982 Global usage is discouraged because of possible performance impact.
  1983 
  1984 * New classes "top" and "bot" with corresponding operations "top" and
  1985 "bot" in theory Orderings; instantiation of class "complete_lattice"
  1986 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  1987 
  1988 * Changed definition lemma "less_fun_def" in order to provide an
  1989 instance for preorders on functions; use lemma "less_le" instead.
  1990 INCOMPATIBILITY.
  1991 
  1992 * Theory Orderings: class "wellorder" moved here, with explicit
  1993 induction rule "less_induct" as assumption.  For instantiation of
  1994 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1995 INCOMPATIBILITY.
  1996 
  1997 * Theory Orderings: added class "preorder" as superclass of "order".
  1998 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1999 etc. slightly changed.  Some theorems named order_class.* now named
  2000 preorder_class.*.
  2001 
  2002 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2003 "diag" to "Id_on".
  2004 
  2005 * Theory Finite_Set: added a new fold combinator of type
  2006 
  2007   ('a => 'b => 'b) => 'b => 'a set => 'b
  2008 
  2009 Occasionally this is more convenient than the old fold combinator
  2010 which is now defined in terms of the new one and renamed to
  2011 fold_image.
  2012 
  2013 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2014 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2015 extended with further lemmas!).  At the moment both still exist but
  2016 the former will disappear at some point.
  2017 
  2018 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2019 class recpower.  Type-specific simp rules for various recpower types
  2020 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2021 
  2022 rat_power_0    -> power_0
  2023 rat_power_Suc  -> power_Suc
  2024 realpow_0      -> power_0
  2025 realpow_Suc    -> power_Suc
  2026 complexpow_0   -> power_0
  2027 complexpow_Suc -> power_Suc
  2028 power_poly_0   -> power_0
  2029 power_poly_Suc -> power_Suc
  2030 
  2031 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2032 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2033 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2034 of lemmas from Divides has been generalized from nat to class
  2035 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2036 renames resulting from duplicate elimination:
  2037 
  2038     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2039     zero_dvd_iff ~>         dvd_0_left_iff
  2040     dvd_0 ~>                dvd_0_right
  2041     DIVISION_BY_ZERO_DIV ~> div_by_0
  2042     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2043     mult_div ~>             div_mult_self2_is_id
  2044     mult_mod ~>             mod_mult_self2_is_0
  2045 
  2046 * Theory IntDiv: removed many lemmas that are instances of class-based
  2047 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2048 rename old lemmas as follows:
  2049 
  2050 dvd_diff               -> nat_dvd_diff
  2051 dvd_zminus_iff         -> dvd_minus_iff
  2052 mod_add1_eq            -> mod_add_eq
  2053 mod_mult1_eq           -> mod_mult_right_eq
  2054 mod_mult1_eq'          -> mod_mult_left_eq
  2055 mod_mult_distrib_mod   -> mod_mult_eq
  2056 nat_mod_add_left_eq    -> mod_add_left_eq
  2057 nat_mod_add_right_eq   -> mod_add_right_eq
  2058 nat_mod_div_trivial    -> mod_div_trivial
  2059 nat_mod_mod_trivial    -> mod_mod_trivial
  2060 zdiv_zadd_self1        -> div_add_self1
  2061 zdiv_zadd_self2        -> div_add_self2
  2062 zdiv_zmult_self1       -> div_mult_self2_is_id
  2063 zdiv_zmult_self2       -> div_mult_self1_is_id
  2064 zdvd_triv_left         -> dvd_triv_left
  2065 zdvd_triv_right        -> dvd_triv_right
  2066 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2067 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2068 zmod_zadd_left_eq      -> mod_add_left_eq
  2069 zmod_zadd_right_eq     -> mod_add_right_eq
  2070 zmod_zadd_self1        -> mod_add_self1
  2071 zmod_zadd_self2        -> mod_add_self2
  2072 zmod_zadd1_eq          -> mod_add_eq
  2073 zmod_zdiff1_eq         -> mod_diff_eq
  2074 zmod_zdvd_zmod         -> mod_mod_cancel
  2075 zmod_zmod_cancel       -> mod_mod_cancel
  2076 zmod_zmult_self1       -> mod_mult_self2_is_0
  2077 zmod_zmult_self2       -> mod_mult_self1_is_0
  2078 zmod_1                 -> mod_by_1
  2079 zdiv_1                 -> div_by_1
  2080 zdvd_abs1              -> abs_dvd_iff
  2081 zdvd_abs2              -> dvd_abs_iff
  2082 zdvd_refl              -> dvd_refl
  2083 zdvd_trans             -> dvd_trans
  2084 zdvd_zadd              -> dvd_add
  2085 zdvd_zdiff             -> dvd_diff
  2086 zdvd_zminus_iff        -> dvd_minus_iff
  2087 zdvd_zminus2_iff       -> minus_dvd_iff
  2088 zdvd_zmultD            -> dvd_mult_right
  2089 zdvd_zmultD2           -> dvd_mult_left
  2090 zdvd_zmult_mono        -> mult_dvd_mono
  2091 zdvd_0_right           -> dvd_0_right
  2092 zdvd_0_left            -> dvd_0_left_iff
  2093 zdvd_1_left            -> one_dvd
  2094 zminus_dvd_iff         -> minus_dvd_iff
  2095 
  2096 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2097 
  2098 * The real numbers offer decimal input syntax: 12.34 is translated
  2099 into 1234/10^2. This translation is not reversed upon output.
  2100 
  2101 * Theory Library/Polynomial defines an abstract type 'a poly of
  2102 univariate polynomials with coefficients of type 'a.  In addition to
  2103 the standard ring operations, it also supports div and mod.  Code
  2104 generation is also supported, using list-style constructors.
  2105 
  2106 * Theory Library/Inner_Product defines a class of real_inner for real
  2107 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2108 => real.  Class real_inner is a subclass of real_normed_vector from
  2109 theory RealVector.
  2110 
  2111 * Theory Library/Product_Vector provides instances for the product
  2112 type 'a * 'b of several classes from RealVector and Inner_Product.
  2113 Definitions of addition, subtraction, scalar multiplication, norms,
  2114 and inner products are included.
  2115 
  2116 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2117 addition to the field operations, numerals and case syntax are also
  2118 supported.
  2119 
  2120 * Theory Library/Diagonalize provides constructive version of Cantor's
  2121 first diagonalization argument.
  2122 
  2123 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2124 zlcm (for int); carried together from various gcd/lcm developements in
  2125 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2126 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2127 may recover tupled syntax as follows:
  2128 
  2129     hide (open) const gcd
  2130     abbreviation gcd where
  2131       "gcd == (%(a, b). GCD.gcd a b)"
  2132     notation (output)
  2133       GCD.gcd ("gcd '(_, _')")
  2134 
  2135 The same works for lcm, zgcd, zlcm.
  2136 
  2137 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2138 instantiations for algebraic structures.  Removed some duplicate
  2139 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2140 
  2141 * ML antiquotation @{code} takes a constant as argument and generates
  2142 corresponding code in background and inserts name of the corresponding
  2143 resulting ML value/function/datatype constructor binding in place.
  2144 All occurrences of @{code} with a single ML block are generated
  2145 simultaneously.  Provides a generic and safe interface for
  2146 instrumentalizing code generation.  See
  2147 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2148 In future you ought to refrain from ad-hoc compiling generated SML
  2149 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2150 cannot refer to constants for which user-defined serializations are
  2151 set.  Refer to the corresponding ML counterpart directly in that
  2152 cases.
  2153 
  2154 * Command 'rep_datatype': instead of theorem names the command now
  2155 takes a list of terms denoting the constructors of the type to be
  2156 represented as datatype.  The characteristic theorems have to be
  2157 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2158 have disappeared in favour of existing ones:
  2159 
  2160     unit_induct                 ~> unit.induct
  2161     prod_induct                 ~> prod.induct
  2162     sum_induct                  ~> sum.induct
  2163     Suc_Suc_eq                  ~> nat.inject
  2164     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2165 
  2166 
  2167 *** HOL-Algebra ***
  2168 
  2169 * New locales for orders and lattices where the equivalence relation
  2170 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2171 locales use a record structure with field eq for the equivalence.
  2172 
  2173 * New theory of factorial domains.
  2174 
  2175 * Units_l_inv and Units_r_inv are now simp rules by default.
  2176 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2177 and/or r_inv will now also require deletion of these lemmas.
  2178 
  2179 * Renamed the following theorems, INCOMPATIBILITY:
  2180 
  2181 UpperD ~> Upper_memD
  2182 LowerD ~> Lower_memD
  2183 least_carrier ~> least_closed
  2184 greatest_carrier ~> greatest_closed
  2185 greatest_Lower_above ~> greatest_Lower_below
  2186 one_zero ~> carrier_one_zero
  2187 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2188 
  2189 
  2190 *** HOL-Nominal ***
  2191 
  2192 * Nominal datatypes can now contain type-variables.
  2193 
  2194 * Commands 'nominal_inductive' and 'equivariance' work with local
  2195 theory targets.
  2196 
  2197 * Nominal primrec can now works with local theory targets and its
  2198 specification syntax now conforms to the general format as seen in
  2199 'inductive' etc.
  2200 
  2201 * Method "perm_simp" honours the standard simplifier attributes
  2202 (no_asm), (no_asm_use) etc.
  2203 
  2204 * The new predicate #* is defined like freshness, except that on the
  2205 left hand side can be a set or list of atoms.
  2206 
  2207 * Experimental command 'nominal_inductive2' derives strong induction
  2208 principles for inductive definitions.  In contrast to
  2209 'nominal_inductive', which can only deal with a fixed number of
  2210 binders, it can deal with arbitrary expressions standing for sets of
  2211 atoms to be avoided.  The only inductive definition we have at the
  2212 moment that needs this generalisation is the typing rule for Lets in
  2213 the algorithm W:
  2214 
  2215  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2216  -----------------------------------------------------------------
  2217          Gamma |- Let x be t1 in t2 : T2
  2218 
  2219 In this rule one wants to avoid all the binders that are introduced by
  2220 "close Gamma T1".  We are looking for other examples where this
  2221 feature might be useful.  Please let us know.
  2222 
  2223 
  2224 *** HOLCF ***
  2225 
  2226 * Reimplemented the simplification procedure for proving continuity
  2227 subgoals.  The new simproc is extensible; users can declare additional
  2228 continuity introduction rules with the attribute [cont2cont].
  2229 
  2230 * The continuity simproc now uses a different introduction rule for
  2231 solving continuity subgoals on terms with lambda abstractions.  In
  2232 some rare cases the new simproc may fail to solve subgoals that the
  2233 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2234 Potential INCOMPATIBILITY.
  2235 
  2236 * Command 'fixrec': specification syntax now conforms to the general
  2237 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2238 examples.  INCOMPATIBILITY.
  2239 
  2240 
  2241 *** ZF ***
  2242 
  2243 * Proof of Zorn's Lemma for partial orders.
  2244 
  2245 
  2246 *** ML ***
  2247 
  2248 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2249 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2250 depends on multithreading, so timouts will not work before Poly/ML
  2251 5.2.1!
  2252 
  2253 * High-level support for concurrent ML programming, see
  2254 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2255 particularly convenient to organize independent functional
  2256 computations.  The concept of "synchronized variables" provides a
  2257 higher-order interface for components with shared state, avoiding the
  2258 delicate details of mutexes and condition variables.  (Requires
  2259 Poly/ML 5.2.1 or later.)
  2260 
  2261 * ML bindings produced via Isar commands are stored within the Isar
  2262 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2263 become thread-safe and work with undo as expected (concerning
  2264 top-level bindings, not side-effects on global references).
  2265 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2266 compiler at runtime; really global bindings need to be given outside a
  2267 theory.  (Requires Poly/ML 5.2 or later.)
  2268 
  2269 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2270 context.  Top-level ML bindings are stored within the proof context in
  2271 a purely sequential fashion, disregarding the nested proof structure.
  2272 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2273 proof.  (Requires Poly/ML 5.2 or later.)
  2274 
  2275 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2276 and Method.setup, as well as Isar commands 'attribute_setup' and
  2277 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2278 existing code accordingly, or use plain 'setup' together with old
  2279 Method.add_method.
  2280 
  2281 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2282 to 'a -> thm, while results are always tagged with an authentic oracle
  2283 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2284 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2285 accordingly.  Note that extra performance may be gained by producing
  2286 the cterm carefully, avoiding slow Thm.cterm_of.
  2287 
  2288 * Simplified interface for defining document antiquotations via
  2289 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2290 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2291 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2292 examples.
  2293 
  2294 * More systematic treatment of long names, abstract name bindings, and
  2295 name space operations.  Basic operations on qualified names have been
  2296 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2297 Long_Name.append.  Old type bstring has been mostly replaced by
  2298 abstract type binding (see structure Binding), which supports precise
  2299 qualification by packages and local theory targets, as well as proper
  2300 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2301 bstring values into Binding.name, or better pass through abstract
  2302 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2303 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2304 
  2305 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2306 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2307 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2308 
  2309 * Disposed old type and term read functions (Sign.read_def_typ,
  2310 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2311 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2312 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2313 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2314 resort for legacy applications.
  2315 
  2316 * Disposed old declarations, tactics, tactic combinators that refer to
  2317 the simpset or claset of an implicit theory (such as Addsimps,
  2318 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2319 embedded ML text, or local_simpset_of with a proper context passed as
  2320 explicit runtime argument.
  2321 
  2322 * Rules and tactics that read instantiations (read_instantiate,
  2323 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2324 context, which is required for parsing and type-checking.  Moreover,
  2325 the variables are specified as plain indexnames, not string encodings
  2326 thereof.  INCOMPATIBILITY.
  2327 
  2328 * Generic Toplevel.add_hook interface allows to analyze the result of
  2329 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2330 for theorem dependency output of transactions resulting in a new
  2331 theory state.
  2332 
  2333 * ML antiquotations: block-structured compilation context indicated by
  2334 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2335 
  2336   @{binding name}                         - basic name binding
  2337   @{let ?pat = term}                      - term abbreviation (HO matching)
  2338   @{note name = fact}                     - fact abbreviation
  2339   @{thm fact}                             - singleton fact (with attributes)
  2340   @{thms fact}                            - general fact (with attributes)
  2341   @{lemma prop by method}                 - singleton goal
  2342   @{lemma prop by meth1 meth2}            - singleton goal
  2343   @{lemma prop1 ... propN by method}      - general goal
  2344   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2345   @{lemma (open) ...}                     - open derivation
  2346 
  2347 
  2348 *** System ***
  2349 
  2350 * The Isabelle "emacs" tool provides a specific interface to invoke
  2351 Proof General / Emacs, with more explicit failure if that is not
  2352 installed (the old isabelle-interface script silently falls back on
  2353 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2354 installation location of the Proof General distribution.
  2355 
  2356 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2357 the Isabelle process into a JVM/Scala application.  See
  2358 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2359 process wrapper has been discontinued.)
  2360 
  2361 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2362 
  2363 * Various status messages (with exact source position information) are
  2364 emitted, if proper markup print mode is enabled.  This allows
  2365 user-interface components to provide detailed feedback on internal
  2366 prover operations.
  2367 
  2368 
  2369 
  2370 New in Isabelle2008 (June 2008)
  2371 -------------------------------
  2372 
  2373 *** General ***
  2374 
  2375 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2376 and updated, with formally checked references as hyperlinks.
  2377 
  2378 * Theory loader: use_thy (and similar operations) no longer set the
  2379 implicit ML context, which was occasionally hard to predict and in
  2380 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2381 provides a proper context already.
  2382 
  2383 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2384 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2385 'use' within a theory file will do the job.
  2386 
  2387 * Name space merge now observes canonical order, i.e. the second space
  2388 is inserted into the first one, while existing entries in the first
  2389 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2390 swap theory imports.
  2391 
  2392 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2393 INCOMPATIBILITY in identifier syntax etc.
  2394 
  2395 * Outer syntax: string tokens no longer admit escaped white space,
  2396 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2397 white space without escapes.
  2398 
  2399 * Outer syntax: string tokens may contain arbitrary character codes
  2400 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2401 "foo_bar".
  2402 
  2403 
  2404 *** Pure ***
  2405 
  2406 * Context-dependent token translations.  Default setup reverts locally
  2407 fixed variables, and adds hilite markup for undeclared frees.
  2408 
  2409 * Unused theorems can be found using the new command 'unused_thms'.
  2410 There are three ways of invoking it:
  2411 
  2412 (1) unused_thms
  2413      Only finds unused theorems in the current theory.
  2414 
  2415 (2) unused_thms thy_1 ... thy_n -
  2416      Finds unused theorems in the current theory and all of its ancestors,
  2417      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2418 
  2419 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2420      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2421      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2422      their ancestors.
  2423 
  2424 In order to increase the readability of the list produced by
  2425 unused_thms, theorems that have been created by a particular instance
  2426 of a theory command such as 'inductive' or 'function' are considered
  2427 to belong to the same "group", meaning that if at least one theorem in
  2428 this group is used, the other theorems in the same group are no longer
  2429 reported as unused.  Moreover, if all theorems in the group are
  2430 unused, only one theorem in the group is displayed.
  2431 
  2432 Note that proof objects have to be switched on in order for
  2433 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2434 usually the case when using Proof General with the default settings).
  2435 
  2436 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2437 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2438 duplicate fact bindings, or even accidental fact duplications.  Note
  2439 that tools may maintain dynamically scoped facts systematically, using
  2440 PureThy.add_thms_dynamic.
  2441 
  2442 * Command 'hide' now allows to hide from "fact" name space as well.
  2443 
  2444 * Eliminated destructive theorem database, simpset, claset, and
  2445 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2446 update of theories within ML code.
  2447 
  2448 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2449 INCOMPATIBILITY, object-logics depending on former Pure require
  2450 additional setup PureThy.old_appl_syntax_setup; object-logics
  2451 depending on former CPure need to refer to Pure.
  2452 
  2453 * Commands 'use' and 'ML' are now purely functional, operating on
  2454 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2455 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2456 INCOMPATIBILITY.
  2457 
  2458 * Command 'setup': discontinued implicit version with ML reference.
  2459 
  2460 * Instantiation target allows for simultaneous specification of class
  2461 instance operations together with an instantiation proof.
  2462 Type-checking phase allows to refer to class operations uniformly.
  2463 See src/HOL/Complex/Complex.thy for an Isar example and
  2464 src/HOL/Library/Eval.thy for an ML example.
  2465 
  2466 * Indexing of literal facts: be more serious about including only
  2467 facts from the visible specification/proof context, but not the
  2468 background context (locale etc.).  Affects `prop` notation and method
  2469 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2470 situations.
  2471 
  2472 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2473 "(open)" option, which used to expose internal bound variables to the
  2474 proof text.
  2475 
  2476 * Isar statements: removed obsolete case "rule_context".
  2477 INCOMPATIBILITY, better use explicit fixes/assumes.
  2478 
  2479 * Locale proofs: default proof step now includes 'unfold_locales';
  2480 hence 'proof' without argument may be used to unfold locale
  2481 predicates.
  2482 
  2483 
  2484 *** Document preparation ***
  2485 
  2486 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2487 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2488 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2489 spot); renamed link color from "darkblue" to "linkcolor" (default
  2490 value unchanged, can be redefined via \definecolor); no longer sets
  2491 "a4paper" option (unnecessary or even intrusive).
  2492 
  2493 * Antiquotation @{lemma A method} proves proposition A by the given
  2494 method (either a method name or a method name plus (optional) method
  2495 arguments in parentheses) and prints A just like @{prop A}.
  2496 
  2497 
  2498 *** HOL ***
  2499 
  2500 * New primrec package.  Specification syntax conforms in style to
  2501 definition/function/....  No separate induction rule is provided.  The
  2502 "primrec" command distinguishes old-style and new-style specifications
  2503 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2504 When adjusting theories, beware: constants stemming from new-style
  2505 primrec specifications have authentic syntax.
  2506 
  2507 * Metis prover is now an order of magnitude faster, and also works
  2508 with multithreading.
  2509 
  2510 * Metis: the maximum number of clauses that can be produced from a
  2511 theorem is now given by the attribute max_clauses.  Theorems that
  2512 exceed this number are ignored, with a warning printed.
  2513 
  2514 * Sledgehammer no longer produces structured proofs by default. To
  2515 enable, declare [[sledgehammer_full = true]].  Attributes
  2516 reconstruction_modulus, reconstruction_sorts renamed
  2517 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2518 
  2519 * Method "induct_scheme" derives user-specified induction rules
  2520 from well-founded induction and completeness of patterns. This factors
  2521 out some operations that are done internally by the function package
  2522 and makes them available separately.  See
  2523 src/HOL/ex/Induction_Scheme.thy for examples.
  2524 
  2525 * More flexible generation of measure functions for termination
  2526 proofs: Measure functions can be declared by proving a rule of the
  2527 form "is_measure f" and giving it the [measure_function] attribute.
  2528 The "is_measure" predicate is logically meaningless (always true), and
  2529 just guides the heuristic.  To find suitable measure functions, the
  2530 termination prover sets up the goal "is_measure ?f" of the appropriate
  2531 type and generates all solutions by prolog-style backwards proof using
  2532 the declared rules.
  2533 
  2534 This setup also deals with rules like 
  2535 
  2536   "is_measure f ==> is_measure (list_size f)"
  2537 
  2538 which accommodates nested datatypes that recurse through lists.
  2539 Similar rules are predeclared for products and option types.
  2540 
  2541 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2542 
  2543   INCOMPATIBILITIES:
  2544 
  2545   - Definitions of overloaded constants on sets have to be replaced by
  2546     definitions on => and bool.
  2547 
  2548   - Some definitions of overloaded operators on sets can now be proved
  2549     using the definitions of the operators on => and bool.  Therefore,
  2550     the following theorems have been renamed:
  2551 
  2552       subset_def   -> subset_eq
  2553       psubset_def  -> psubset_eq
  2554       set_diff_def -> set_diff_eq
  2555       Compl_def    -> Compl_eq
  2556       Sup_set_def  -> Sup_set_eq
  2557       Inf_set_def  -> Inf_set_eq
  2558       sup_set_def  -> sup_set_eq
  2559       inf_set_def  -> inf_set_eq
  2560 
  2561   - Due to the incompleteness of the HO unification algorithm, some
  2562     rules such as subst may require manual instantiation, if some of
  2563     the unknowns in the rule is a set.
  2564 
  2565   - Higher order unification and forward proofs:
  2566     The proof pattern
  2567 
  2568       have "P (S::'a set)" <...>
  2569       then have "EX S. P S" ..
  2570 
  2571     no longer works (due to the incompleteness of the HO unification
  2572     algorithm) and must be replaced by the pattern
  2573 
  2574       have "EX S. P S"
  2575       proof
  2576         show "P S" <...>
  2577       qed
  2578 
  2579   - Calculational reasoning with subst (or similar rules):
  2580     The proof pattern
  2581 
  2582       have "P (S::'a set)" <...>
  2583       also have "S = T" <...>
  2584       finally have "P T" .
  2585 
  2586     no longer works (for similar reasons as the previous example) and
  2587     must be replaced by something like
  2588 
  2589       have "P (S::'a set)" <...>
  2590       moreover have "S = T" <...>
  2591       ultimately have "P T" by simp
  2592 
  2593   - Tactics or packages written in ML code:
  2594     Code performing pattern matching on types via
  2595 
  2596       Type ("set", [T]) => ...
  2597 
  2598     must be rewritten. Moreover, functions like strip_type or
  2599     binder_types no longer return the right value when applied to a
  2600     type of the form
  2601 
  2602       T1 => ... => Tn => U => bool
  2603 
  2604     rather than
  2605 
  2606       T1 => ... => Tn => U set
  2607 
  2608 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2609 Wellfounded_Relations to theory Wellfounded.
  2610 
  2611 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2612 
  2613 * Class finite no longer treats UNIV as class parameter.  Use class
  2614 enum from theory Library/Enum instead to achieve a similar effect.
  2615 INCOMPATIBILITY.
  2616 
  2617 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2618 and "Cons".  INCOMPATIBILITY.
  2619 
  2620 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2621 Potential INCOMPATIBILITY.
  2622 
  2623 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2624 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2625 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2626 
  2627 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2628 the same name in theory Orderings:
  2629 
  2630   less_trans
  2631   less_linear
  2632   le_imp_less_or_eq
  2633   le_less_trans
  2634   less_le_trans
  2635   less_not_sym
  2636   less_asym
  2637 
  2638 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2639 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2640 and different variable names.
  2641 
  2642 * Library/Option_ord.thy: Canonical order on option type.
  2643 
  2644 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2645 finite maps.
  2646 
  2647 * Library/Countable.thy: Type class for countable types.
  2648 
  2649 * Theory Int: The representation of numerals has changed.  The infix
  2650 operator BIT and the bit datatype with constructors B0 and B1 have
  2651 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2652 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2653 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2654 accordingly.
  2655 
  2656 * Theory Nat: definition of <= and < on natural numbers no longer
  2657 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2658 le_def and less_def have disappeared.  Consider lemmas not_less
  2659 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2660 
  2661 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2662 (whose purpose mainly is for various fold_set functionals) have been
  2663 abandoned in favor of the existing algebraic classes
  2664 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2665 lower_semilattice (resp. upper_semilattice) and linorder.
  2666 INCOMPATIBILITY.
  2667 
  2668 * Theory Transitive_Closure: induct and cases rules now declare proper
  2669 case_names ("base" and "step").  INCOMPATIBILITY.
  2670 
  2671 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2672 lattices.  The form set-specific version is available as
  2673 Inductive.lfp_ordinal_induct_set.
  2674 
  2675 * Renamed theorems "power.simps" to "power_int.simps".
  2676 INCOMPATIBILITY.
  2677 
  2678 * Class semiring_div provides basic abstract properties of semirings
  2679 with division and modulo operations.  Subsumes former class dvd_mod.
  2680 
  2681 * Merged theories IntDef, Numeral and IntArith into unified theory
  2682 Int.  INCOMPATIBILITY.
  2683 
  2684 * Theory Library/Code_Index: type "index" now represents natural
  2685 numbers rather than integers.  INCOMPATIBILITY.
  2686 
  2687 * New class "uminus" with operation "uminus" (split of from class
  2688 "minus" which now only has operation "minus", binary).
  2689 INCOMPATIBILITY.
  2690 
  2691 * Constants "card", "internal_split", "option_map" now with authentic
  2692 syntax.  INCOMPATIBILITY.
  2693 
  2694 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2695 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2696 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2697 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2698 Sup_set_def, le_def, less_def, option_map_def now with object
  2699 equality.  INCOMPATIBILITY.
  2700 
  2701 * Records. Removed K_record, and replaced it by pure lambda term
  2702 %x. c. The simplifier setup is now more robust against eta expansion.
  2703 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2704 
  2705 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2706 
  2707 * Library/ListVector: new theory of arithmetic vector operations.
  2708 
  2709 * Library/Order_Relation: new theory of various orderings as sets of
  2710 pairs.  Defines preorders, partial orders, linear orders and
  2711 well-orders on sets and on types.
  2712 
  2713 
  2714 *** ZF ***
  2715 
  2716 * Renamed some theories to allow to loading both ZF and HOL in the
  2717 same session:
  2718 
  2719   Datatype  -> Datatype_ZF
  2720   Inductive -> Inductive_ZF
  2721   Int       -> Int_ZF
  2722   IntDiv    -> IntDiv_ZF
  2723   Nat       -> Nat_ZF
  2724   List      -> List_ZF
  2725   Main      -> Main_ZF
  2726 
  2727 INCOMPATIBILITY: ZF theories that import individual theories below
  2728 Main might need to be adapted.  Regular theory Main is still
  2729 available, as trivial extension of Main_ZF.
  2730 
  2731 
  2732 *** ML ***
  2733 
  2734 * ML within Isar: antiquotation @{const name} or @{const
  2735 name(typargs)} produces statically-checked Const term.
  2736 
  2737 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2738 (of the same name).  Removed obsolete print command.
  2739 
  2740 * Removed obsolete "use_legacy_bindings" function.
  2741 
  2742 * The ``print mode'' is now a thread-local value derived from a global
  2743 template (the former print_mode reference), thus access becomes
  2744 non-critical.  The global print_mode reference is for session
  2745 management only; user-code should use print_mode_value,
  2746 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2747 
  2748 * Functions system/system_out provide a robust way to invoke external
  2749 shell commands, with propagation of interrupts (requires Poly/ML
  2750 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2751 
  2752 
  2753 *** System ***
  2754 
  2755 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2756 in accordance with Proof General 3.7, which prefers GNU emacs.
  2757 
  2758 * isatool tty runs Isabelle process with plain tty interaction;
  2759 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2760 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2761 
  2762 * isatool browser now works with Cygwin as well, using general
  2763 "javapath" function defined in Isabelle process environment.
  2764 
  2765 * YXML notation provides a simple and efficient alternative to
  2766 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2767 isatool yxml as described in the Isabelle system manual.
  2768 
  2769 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2770 provides general wrapper for managing an Isabelle process in a robust
  2771 fashion, with ``cooked'' output from stdin/stderr.
  2772 
  2773 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2774 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2775 
  2776 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2777 way of changing the user's settings is via
  2778 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2779 script.
  2780 
  2781 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2782 cores of the underlying machine, which is a good starting point for
  2783 optimal performance tuning.  The corresponding usedir option -M allows
  2784 "max" as an alias for "0".  WARNING: does not work on certain versions
  2785 of Mac OS (with Poly/ML 5.1).
  2786 
  2787 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2788 adverse effect of Isabelle flooding interactive front-ends (notably
  2789 ProofGeneral / XEmacs).
  2790 
  2791 
  2792 
  2793 New in Isabelle2007 (November 2007)
  2794 -----------------------------------
  2795 
  2796 *** General ***
  2797 
  2798 * More uniform information about legacy features, notably a
  2799 warning/error of "Legacy feature: ...", depending on the state of the
  2800 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2801 legacy features will disappear eventually.
  2802 
  2803 * Theory syntax: the header format ``theory A = B + C:'' has been
  2804 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2805 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2806 
  2807 * Theory syntax: the old non-Isar theory file format has been
  2808 discontinued altogether.  Note that ML proof scripts may still be used
  2809 with Isar theories; migration is usually quite simple with the ML
  2810 function use_legacy_bindings.  INCOMPATIBILITY.
  2811 
  2812 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2813 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2814 quotes.
  2815 
  2816 * Theory loader: be more serious about observing the static theory
  2817 header specifications (including optional directories), but not the
  2818 accidental file locations of previously successful loads.  The strict
  2819 update policy of former update_thy is now already performed by
  2820 use_thy, so the former has been removed; use_thys updates several
  2821 theories simultaneously, just as 'imports' within a theory header
  2822 specification, but without merging the results.  Potential
  2823 INCOMPATIBILITY: may need to refine theory headers and commands
  2824 ROOT.ML which depend on load order.
  2825 
  2826 * Theory loader: optional support for content-based file
  2827 identification, instead of the traditional scheme of full physical
  2828 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2829 (cf. the system manual).  The new scheme allows to work with
  2830 non-finished theories in persistent session images, such that source
  2831 files may be moved later on without requiring reloads.
  2832 
  2833 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2834 file (with the same base name as the theory) are considered a legacy
  2835 feature, which will disappear eventually. Even now, the theory loader
  2836 no longer maintains dependencies on such files.
  2837 
  2838 * Syntax: the scope for resolving ambiguities via type-inference is
  2839 now limited to individual terms, instead of whole simultaneous
  2840 specifications as before. This greatly reduces the complexity of the
  2841 syntax module and improves flexibility by separating parsing and
  2842 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2843 'fixes' etc.) are required in rare situations.
  2844 
  2845 * Syntax: constants introduced by new-style packages ('definition',
  2846 'abbreviation' etc.) are passed through the syntax module in
  2847 ``authentic mode''. This means that associated mixfix annotations
  2848 really stick to such constants, independently of potential name space
  2849 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2850 trees are represented slightly differently, may need to adapt syntax
  2851 translations accordingly. Use CONST marker in 'translations' and
  2852 @{const_syntax} antiquotation in 'parse_translation' etc.
  2853 
  2854 * Legacy goal package: reduced interface to the bare minimum required
  2855 to keep existing proof scripts running.  Most other user-level
  2856 functions are now part of the OldGoals structure, which is *not* open
  2857 by default (consider isatool expandshort before open OldGoals).
  2858 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2859 these tend to cause confusion about the actual goal (!) context being
  2860 used here, which is not necessarily the same as the_context().
  2861 
  2862 * Command 'find_theorems': supports "*" wild-card in "name:"
  2863 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2864 support a specific search form (see ProofGeneral/CHANGES).
  2865 
  2866 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2867 by default, which means that "prems" (and also "fixed variables") are
  2868 suppressed from proof state output.  Note that the ProofGeneral
  2869 settings mechanism allows to change and save options persistently, but
  2870 older versions of Isabelle will fail to start up if a negative prems
  2871 limit is imposed.
  2872 
  2873 * Local theory targets may be specified by non-nested blocks of
  2874 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2875 contain definitions, theorems etc., including any derived mechanism
  2876 that has been implemented on top of these primitives.  This concept
  2877 generalizes the existing ``theorem (in ...)'' towards more versatility
  2878 and scalability.
  2879 
  2880 * Proof General interface: proper undo of final 'end' command;
  2881 discontinued Isabelle/classic mode (ML proof scripts).
  2882 
  2883 
  2884 *** Document preparation ***
  2885 
  2886 * Added antiquotation @{theory name} which prints the given name,
  2887 after checking that it refers to a valid ancestor theory in the
  2888 current context.
  2889 
  2890 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2891 check the given source text as ML type/structure, printing verbatim.
  2892 
  2893 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2894 "c args == rhs" given in the current context.  (Any number of
  2895 arguments may be given on the LHS.)
  2896 
  2897 
  2898 *** Pure ***
  2899 
  2900 * The 'class' package offers a combination of axclass and locale to
  2901 achieve Haskell-like type classes in Isabelle.  Definitions and
  2902 theorems within a class context produce both relative results (with
  2903 implicit parameters according to the locale context), and polymorphic
  2904 constants with qualified polymorphism (according to the class
  2905 context).  Within the body context of a 'class' target, a separate
  2906 syntax layer ("user space type system") takes care of converting
  2907 between global polymorphic consts and internal locale representation.
  2908 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2909 "isatool doc classes" provides a tutorial.
  2910 
  2911 * Generic code generator framework allows to generate executable
  2912 code for ML and Haskell (including Isabelle classes).  A short usage
  2913 sketch:
  2914 
  2915     internal compilation:
  2916         export_code <list of constants (term syntax)> in SML
  2917     writing SML code to a file:
  2918         export_code <list of constants (term syntax)> in SML <filename>
  2919     writing OCaml code to a file:
  2920         export_code <list of constants (term syntax)> in OCaml <filename>
  2921     writing Haskell code to a bunch of files:
  2922         export_code <list of constants (term syntax)> in Haskell <filename>
  2923 
  2924     evaluating closed propositions to True/False using code generation:
  2925         method ``eval''
  2926 
  2927 Reasonable default setup of framework in HOL.
  2928 
  2929 Theorem attributs for selecting and transforming function equations theorems:
  2930 
  2931     [code fun]:        select a theorem as function equation for a specific constant
  2932     [code fun del]:    deselect a theorem as function equation for a specific constant
  2933     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2934     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2935 
  2936 User-defined serializations (target in {SML, OCaml, Haskell}):
  2937 
  2938     code_const <and-list of constants (term syntax)>
  2939       {(target) <and-list of const target syntax>}+
  2940 
  2941     code_type <and-list of type constructors>
  2942       {(target) <and-list of type target syntax>}+
  2943 
  2944     code_instance <and-list of instances>
  2945       {(target)}+
  2946         where instance ::= <type constructor> :: <class>
  2947 
  2948     code_class <and_list of classes>
  2949       {(target) <and-list of class target syntax>}+
  2950         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  2951 
  2952 code_instance and code_class only are effective to target Haskell.
  2953 
  2954 For example usage see src/HOL/ex/Codegenerator.thy and
  2955 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  2956 generation from Isabelle/HOL theories is available via "isatool doc
  2957 codegen".
  2958 
  2959 * Code generator: consts in 'consts_code' Isar commands are now
  2960 referred to by usual term syntax (including optional type
  2961 annotations).
  2962 
  2963 * Command 'no_translations' removes translation rules from theory
  2964 syntax.
  2965 
  2966 * Overloaded definitions are now actually checked for acyclic
  2967 dependencies.  The overloading scheme is slightly more general than
  2968 that of Haskell98, although Isabelle does not demand an exact
  2969 correspondence to type class and instance declarations.
  2970 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  2971 exotic versions of overloading -- at the discretion of the user!
  2972 
  2973 Polymorphic constants are represented via type arguments, i.e. the
  2974 instantiation that matches an instance against the most general
  2975 declaration given in the signature.  For example, with the declaration
  2976 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  2977 as c(nat).  Overloading is essentially simultaneous structural
  2978 recursion over such type arguments.  Incomplete specification patterns
  2979 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  2980 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  2981 Command 'print_theory' outputs the normalized system of recursive
  2982 equations, see section "definitions".
  2983 
  2984 * Configuration options are maintained within the theory or proof
  2985 context (with name and type bool/int/string), providing a very simple
  2986 interface to a poor-man's version of general context data.  Tools may
  2987 declare options in ML (e.g. using Attrib.config_int) and then refer to
  2988 these values using Config.get etc.  Users may change options via an
  2989 associated attribute of the same name.  This form of context
  2990 declaration works particularly well with commands 'declare' or
  2991 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2992 very easy to avoid global references, which would not observe Isar
  2993 toplevel undo/redo and fail to work with multithreading.
  2994 
  2995 Various global ML references of Pure and HOL have been turned into
  2996 configuration options:
  2997 
  2998   Unify.search_bound		unify_search_bound
  2999   Unify.trace_bound		unify_trace_bound
  3000   Unify.trace_simp		unify_trace_simp
  3001   Unify.trace_types		unify_trace_types
  3002   Simplifier.simp_depth_limit	simp_depth_limit
  3003   Blast.depth_limit		blast_depth_limit
  3004   DatatypeProp.dtK		datatype_distinctness_limit
  3005   fast_arith_neq_limit  	fast_arith_neq_limit
  3006   fast_arith_split_limit	fast_arith_split_limit
  3007 
  3008 * Named collections of theorems may be easily installed as context
  3009 data using the functor NamedThmsFun (see also
  3010 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3011 attributes; there is also a toplevel print command.  This facility is
  3012 just a common case of general context data, which is the preferred way
  3013 for anything more complex than just a list of facts in canonical
  3014 order.
  3015 
  3016 * Isar: command 'declaration' augments a local theory by generic
  3017 declaration functions written in ML.  This enables arbitrary content
  3018 being added to the context, depending on a morphism that tells the
  3019 difference of the original declaration context wrt. the application
  3020 context encountered later on.
  3021 
  3022 * Isar: proper interfaces for simplification procedures.  Command
  3023 'simproc_setup' declares named simprocs (with match patterns, and body
  3024 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3025 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3026 
  3027 * Isar: an extra pair of brackets around attribute declarations
  3028 abbreviates a theorem reference involving an internal dummy fact,
  3029 which will be ignored later --- only the effect of the attribute on
  3030 the background context will persist.  This form of in-place
  3031 declarations is particularly useful with commands like 'declare' and
  3032 'using', for example ``have A using [[simproc a]] by simp''.
  3033 
  3034 * Isar: method "assumption" (and implicit closing of subproofs) now
  3035 takes simple non-atomic goal assumptions into account: after applying
  3036 an assumption as a rule the resulting subgoals are solved by atomic
  3037 assumption steps.  This is particularly useful to finish 'obtain'
  3038 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3039 without referring to the original premise "!!x. P x ==> thesis" in the
  3040 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3041 more permissive.
  3042 
  3043 * Isar: implicit use of prems from the Isar proof context is
  3044 considered a legacy feature.  Common applications like ``have A .''
  3045 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3046 referencing facts explicitly here improves readability and
  3047 maintainability of proof texts.
  3048 
  3049 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3050 the obtained context from the course of reasoning!  For example:
  3051 
  3052   assume "EX x y. A x & B y"   -- "any previous fact"
  3053   then guess x and y by clarify
  3054 
  3055 This technique is potentially adventurous, depending on the facts and
  3056 proof tools being involved here.
  3057 
  3058 * Isar: known facts from the proof context may be specified as literal
  3059 propositions, using ASCII back-quote syntax.  This works wherever
  3060 named facts used to be allowed so far, in proof commands, proof
  3061 methods, attributes etc.  Literal facts are retrieved from the context
  3062 according to unification of type and term parameters.  For example,
  3063 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3064 theorems in the current context, then these are valid literal facts:
  3065 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3066 
  3067 There is also a proof method "fact" which does the same composition
  3068 for explicit goal states, e.g. the following proof texts coincide with
  3069 certain special cases of literal facts:
  3070 
  3071   have "A" by fact                 ==  note `A`
  3072   have "A ==> B" by fact           ==  note `A ==> B`
  3073   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3074   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3075 
  3076 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3077 outer syntax.  Thus symbolic identifiers may be used without
  3078 additional white space in declarations like this: ``assume *: A''.
  3079 
  3080 * Isar: 'print_facts' prints all local facts of the current context,
  3081 both named and unnamed ones.
  3082 
  3083 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3084 
  3085   def x == "t" and y == "u"
  3086 
  3087 * Isar: added command 'unfolding', which is structurally similar to
  3088 'using', but affects both the goal state and facts by unfolding given
  3089 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3090 'unfolded' attribute may be replaced by first-class proof text.
  3091 
  3092 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3093 and command 'unfolding' now all support object-level equalities
  3094 (potentially conditional).  The underlying notion of rewrite rule is
  3095 analogous to the 'rule_format' attribute, but *not* that of the
  3096 Simplifier (which is usually more generous).
  3097 
  3098 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3099 premises of a theorem by n. Useful in conjunction with drule.
  3100 
  3101 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3102 method expression within a sandbox consisting of the first N
  3103 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3104 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3105 simplifies all new goals that emerge from applying rule foo to the
  3106 originally first one.
  3107 
  3108 * Isar: schematic goals are no longer restricted to higher-order
  3109 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3110 expected.
  3111 
  3112 * Isar: the conclusion of a long theorem statement is now either
  3113 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3114 (essentially a disjunction of cases with local parameters and
  3115 assumptions).  The latter allows to express general elimination rules
  3116 adequately; in this notation common elimination rules look like this:
  3117 
  3118   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3119     assumes "EX x. P x"
  3120     obtains x where "P x"
  3121 
  3122   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3123     assumes "A & B"
  3124     obtains A and B
  3125 
  3126   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3127     assumes "A | B"
  3128     obtains
  3129       A
  3130     | B
  3131 
  3132 The subsequent classical rules even refer to the formal "thesis"
  3133 explicitly:
  3134 
  3135   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3136     obtains "~ thesis"
  3137 
  3138   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3139     obtains "thesis ==> something"
  3140 
  3141 The actual proof of an 'obtains' statement is analogous to that of the
  3142 Isar proof element 'obtain', only that there may be several cases.
  3143 Optional case names may be specified in parentheses; these will be
  3144 available both in the present proof and as annotations in the
  3145 resulting rule, for later use with the 'cases' method (cf. attribute
  3146 case_names).
  3147 
  3148 * Isar: the assumptions of a long theorem statement are available as
  3149 "assms" fact in the proof context.  This is more appropriate than the
  3150 (historical) "prems", which refers to all assumptions of the current
  3151 context, including those from the target locale, proof body etc.
  3152 
  3153 * Isar: 'print_statement' prints theorems from the current theory or
  3154 proof context in long statement form, according to the syntax of a
  3155 top-level lemma.
  3156 
  3157 * Isar: 'obtain' takes an optional case name for the local context
  3158 introduction rule (default "that").
  3159 
  3160 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3161 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3162 to occur.
  3163 
  3164 * Pure: syntax "CONST name" produces a fully internalized constant
  3165 according to the current context.  This is particularly useful for
  3166 syntax translations that should refer to internal constant
  3167 representations independently of name spaces.
  3168 
  3169 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3170 instead of "FOO ". This allows multiple binder declarations to coexist
  3171 in the same context.  INCOMPATIBILITY.
  3172 
  3173 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3174 primitive that also works in a locale context (both for constants and
  3175 fixed variables). Type declaration and internal syntactic representation
  3176 of given constants retrieved from the context. Likewise, the
  3177 'no_notation' command allows to remove given syntax annotations from the
  3178 current context.
  3179 
  3180 * Isar/locales: new derived specification elements 'axiomatization',
  3181 'definition', 'abbreviation', which support type-inference, admit
  3182 object-level specifications (equality, equivalence).  See also the
  3183 isar-ref manual.  Examples:
  3184 
  3185   axiomatization
  3186     eq  (infix "===" 50) where
  3187     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3188 
  3189   definition "f x y = x + y + 1"
  3190   definition g where "g x = f x x"
  3191 
  3192   abbreviation
  3193     neq  (infix "=!=" 50) where
  3194     "x =!= y == ~ (x === y)"
  3195 
  3196 These specifications may be also used in a locale context.  Then the
  3197 constants being introduced depend on certain fixed parameters, and the
  3198 constant name is qualified by the locale base name.  An internal
  3199 abbreviation takes care for convenient input and output, making the
  3200 parameters implicit and using the original short name.  See also
  3201 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3202 entities from a monomorphic theory.
  3203 
  3204 Presently, abbreviations are only available 'in' a target locale, but
  3205 not inherited by general import expressions.  Also note that
  3206 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3207 'translations' in common applications.  The "no_abbrevs" print mode
  3208 prevents folding of abbreviations in term output.
  3209 
  3210 Concrete syntax is attached to specified constants in internal form,
  3211 independently of name spaces.  The parse tree representation is
  3212 slightly different -- use 'notation' instead of raw 'syntax', and
  3213 'translations' with explicit "CONST" markup to accommodate this.
  3214 
  3215 * Pure/Isar: unified syntax for new-style specification mechanisms
  3216 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3217 full type inference and dummy patterns ("_").  For example:
  3218 
  3219   definition "K x _ = x"
  3220 
  3221   inductive conj for A B
  3222   where "A ==> B ==> conj A B"
  3223 
  3224 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3225 the current context.  Print mode "no_abbrevs" prevents inversion of
  3226 abbreviations on output.
  3227 
  3228 * Isar/locales: improved parameter handling: use of locales "var" and
  3229 "struct" no longer necessary; - parameter renamings are no longer
  3230 required to be injective.  For example, this allows to define
  3231 endomorphisms as locale endom = homom mult mult h.
  3232 
  3233 * Isar/locales: changed the way locales with predicates are defined.
  3234 Instead of accumulating the specification, the imported expression is
  3235 now an interpretation.  INCOMPATIBILITY: different normal form of
  3236 locale expressions.  In particular, in interpretations of locales with
  3237 predicates, goals repesenting already interpreted fragments are not
  3238 removed automatically.  Use methods `intro_locales' and
  3239 `unfold_locales'; see below.
  3240 
  3241 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3242 provide backward reasoning on locales predicates.  The methods are
  3243 aware of interpretations and discharge corresponding goals.
  3244 `intro_locales' is less aggressive then `unfold_locales' and does not
  3245 unfold predicates to assumptions.
  3246 
  3247 * Isar/locales: the order in which locale fragments are accumulated
  3248 has changed.  This enables to override declarations from fragments due
  3249 to interpretations -- for example, unwanted simp rules.
  3250 
  3251 * Isar/locales: interpretation in theories and proof contexts has been
  3252 extended.  One may now specify (and prove) equations, which are
  3253 unfolded in interpreted theorems.  This is useful for replacing
  3254 defined concepts (constants depending on locale parameters) by
  3255 concepts already existing in the target context.  Example:
  3256 
  3257   interpretation partial_order ["op <= :: [int, int] => bool"]
  3258     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3259 
  3260 Typically, the constant `partial_order.less' is created by a
  3261 definition specification element in the context of locale
  3262 partial_order.
  3263 
  3264 * Method "induct": improved internal context management to support
  3265 local fixes and defines on-the-fly. Thus explicit meta-level
  3266 connectives !!  and ==> are rarely required anymore in inductive goals
  3267 (using object-logic connectives for this purpose has been long
  3268 obsolete anyway). Common proof patterns are explained in
  3269 src/HOL/Induct/Common_Patterns.thy, see also
  3270 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3271 examples.
  3272 
  3273 * Method "induct": improved handling of simultaneous goals. Instead of
  3274 introducing object-level conjunction, the statement is now split into
  3275 several conclusions, while the corresponding symbolic cases are nested
  3276 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3277 see src/HOL/Induct/Common_Patterns.thy, for example.
  3278 
  3279 * Method "induct": mutual induction rules are now specified as a list
  3280 of rule sharing the same induction cases. HOL packages usually provide
  3281 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3282 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3283 mutual induction rules differently, i.e. like this:
  3284 
  3285   (induct rule: foo_bar.inducts)
  3286   (induct set: foo bar)
  3287   (induct pred: foo bar)
  3288   (induct type: foo bar)
  3289 
  3290 The ML function ProjectRule.projections turns old-style rules into the
  3291 new format.
  3292 
  3293 * Method "coinduct": dual of induction, see
  3294 src/HOL/Library/Coinductive_List.thy for various examples.
  3295 
  3296 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3297 considered a legacy feature.
  3298 
  3299 * Attribute "symmetric" produces result with standardized schematic
  3300 variables (index 0).  Potential INCOMPATIBILITY.
  3301 
  3302 * Simplifier: by default the simplifier trace only shows top level
  3303 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3304 default. Thus there is less danger of being flooded by the trace. The
  3305 trace indicates where parts have been suppressed.
  3306   
  3307 * Provers/classical: removed obsolete classical version of elim_format
  3308 attribute; classical elim/dest rules are now treated uniformly when
  3309 manipulating the claset.
  3310 
  3311 * Provers/classical: stricter checks to ensure that supplied intro,
  3312 dest and elim rules are well-formed; dest and elim rules must have at
  3313 least one premise.
  3314 
  3315 * Provers/classical: attributes dest/elim/intro take an optional
  3316 weight argument for the rule (just as the Pure versions).  Weights are
  3317 ignored by automated tools, but determine the search order of single
  3318 rule steps.
  3319 
  3320 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3321 where the body does not mention the bound variable.  Note that dummy
  3322 patterns implicitly depend on their context of bounds, which makes
  3323 "{_. _}" match any set comprehension as expected.  Potential
  3324 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3325 constant "_idtdummy" in the binding position.
  3326 
  3327 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3328 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3329 for example "A -> B" => "Pi A (%_. B)".
  3330 
  3331 * Pure: 'class_deps' command visualizes the subclass relation, using
  3332 the graph browser tool.
  3333 
  3334 * Pure: 'print_theory' now suppresses certain internal declarations by
  3335 default; use '!' option for full details.
  3336 
  3337 
  3338 *** HOL ***
  3339 
  3340 * Method "metis" proves goals by applying the Metis general-purpose
  3341 resolution prover (see also http://gilith.com/software/metis/).
  3342 Examples are in the directory MetisExamples.  WARNING: the
  3343 Isabelle/HOL-Metis integration does not yet work properly with
  3344 multi-threading.
  3345   
  3346 * Command 'sledgehammer' invokes external automatic theorem provers as
  3347 background processes.  It generates calls to the "metis" method if
  3348 successful. These can be pasted into the proof.  Users do not have to
  3349 wait for the automatic provers to return.  WARNING: does not really
  3350 work with multi-threading.
  3351 
  3352 * New "auto_quickcheck" feature tests outermost goal statements for
  3353 potential counter-examples.  Controlled by ML references
  3354 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3355 5000 milliseconds).  Fails silently if statements is outside of
  3356 executable fragment, or any other codgenerator problem occurs.
  3357 
  3358 * New constant "undefined" with axiom "undefined x = undefined".
  3359 
  3360 * Added class "HOL.eq", allowing for code generation with polymorphic
  3361 equality.
  3362 
  3363 * Some renaming of class constants due to canonical name prefixing in
  3364 the new 'class' package:
  3365 
  3366     HOL.abs ~> HOL.abs_class.abs
  3367     HOL.divide ~> HOL.divide_class.divide
  3368     0 ~> HOL.zero_class.zero
  3369     1 ~> HOL.one_class.one
  3370     op + ~> HOL.plus_class.plus
  3371     op - ~> HOL.minus_class.minus
  3372     uminus ~> HOL.minus_class.uminus
  3373     op * ~> HOL.times_class.times
  3374     op < ~> HOL.ord_class.less
  3375     op <= > HOL.ord_class.less_eq
  3376     Nat.power ~> Power.power_class.power
  3377     Nat.size ~> Nat.size_class.size
  3378     Numeral.number_of ~> Numeral.number_class.number_of
  3379     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3380     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3381     Orderings.min ~> Orderings.ord_class.min
  3382     Orderings.max ~> Orderings.ord_class.max
  3383     Divides.op div ~> Divides.div_class.div
  3384     Divides.op mod ~> Divides.div_class.mod
  3385     Divides.op dvd ~> Divides.div_class.dvd
  3386 
  3387 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3388 
  3389 a) User-defined constants using any of the names "plus", "minus",
  3390 "times", "less" or "less_eq". The standard syntax translations for
  3391 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3392 names.
  3393 
  3394 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3395 INCOMPATIBILITY: use more specific names.
  3396 
  3397 c) Permutative equations (e.g. "a + b = b + a")
  3398 Since the change of names also changes the order of terms, permutative
  3399 rewrite rules may get applied in a different order. Experience shows
  3400 that this is rarely the case (only two adaptions in the whole Isabelle
  3401 distribution).  INCOMPATIBILITY: rewrite proofs
  3402 
  3403 d) ML code directly refering to constant names
  3404 This in general only affects hand-written proof tactics, simprocs and
  3405 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3406 Consider using @{const_name} antiquotation.
  3407 
  3408 * New class "default" with associated constant "default".
  3409 
  3410 * Function "sgn" is now overloaded and available on int, real, complex
  3411 (and other numeric types), using class "sgn".  Two possible defs of
  3412 sgn are given as equational assumptions in the classes sgn_if and
  3413 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3414 INCOMPATIBILITY.
  3415 
  3416 * Locale "partial_order" now unified with class "order" (cf. theory
  3417 Orderings), added parameter "less".  INCOMPATIBILITY.
  3418 
  3419 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3420 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3421 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3422 
  3423 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3424 changed order of proof goals in instance proofs.
  3425 
  3426 * The transitivity reasoner for partial and linear orders is set up
  3427 for classes "order" and "linorder".  Instances of the reasoner are available
  3428 in all contexts importing or interpreting the corresponding locales.
  3429 Method "order" invokes the reasoner separately; the reasoner
  3430 is also integrated with the Simplifier as a solver.  Diagnostic
  3431 command 'print_orders' shows the available instances of the reasoner
  3432 in the current context.
  3433 
  3434 * Localized monotonicity predicate in theory "Orderings"; integrated
  3435 lemmas max_of_mono and min_of_mono with this predicate.
  3436 INCOMPATIBILITY.
  3437 
  3438 * Formulation of theorem "dense" changed slightly due to integration
  3439 with new class dense_linear_order.
  3440 
  3441 * Uniform lattice theory development in HOL.
  3442 
  3443     constants "meet" and "join" now named "inf" and "sup"
  3444     constant "Meet" now named "Inf"
  3445 
  3446     classes "meet_semilorder" and "join_semilorder" now named
  3447       "lower_semilattice" and "upper_semilattice"
  3448     class "lorder" now named "lattice"
  3449     class "comp_lat" now named "complete_lattice"
  3450 
  3451     Instantiation of lattice classes allows explicit definitions
  3452     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3453 
  3454   INCOMPATIBILITY.  Theorem renames:
  3455 
  3456     meet_left_le            ~> inf_le1
  3457     meet_right_le           ~> inf_le2
  3458     join_left_le            ~> sup_ge1
  3459     join_right_le           ~> sup_ge2
  3460     meet_join_le            ~> inf_sup_ord
  3461     le_meetI                ~> le_infI
  3462     join_leI                ~> le_supI
  3463     le_meet                 ~> le_inf_iff
  3464     le_join                 ~> ge_sup_conv
  3465     meet_idempotent         ~> inf_idem
  3466     join_idempotent         ~> sup_idem
  3467     meet_comm               ~> inf_commute
  3468     join_comm               ~> sup_commute
  3469     meet_leI1               ~> le_infI1
  3470     meet_leI2               ~> le_infI2
  3471     le_joinI1               ~> le_supI1
  3472     le_joinI2               ~> le_supI2
  3473     meet_assoc              ~> inf_assoc
  3474     join_assoc              ~> sup_assoc
  3475     meet_left_comm          ~> inf_left_commute
  3476     meet_left_idempotent    ~> inf_left_idem
  3477     join_left_comm          ~> sup_left_commute
  3478     join_left_idempotent    ~> sup_left_idem
  3479     meet_aci                ~> inf_aci
  3480     join_aci                ~> sup_aci
  3481     le_def_meet             ~> le_iff_inf
  3482     le_def_join             ~> le_iff_sup
  3483     join_absorp2            ~> sup_absorb2
  3484     join_absorp1            ~> sup_absorb1
  3485     meet_absorp1            ~> inf_absorb1
  3486     meet_absorp2            ~> inf_absorb2
  3487     meet_join_absorp        ~> inf_sup_absorb
  3488     join_meet_absorp        ~> sup_inf_absorb
  3489     distrib_join_le         ~> distrib_sup_le
  3490     distrib_meet_le         ~> distrib_inf_le
  3491 
  3492     add_meet_distrib_left   ~> add_inf_distrib_left
  3493     add_join_distrib_left   ~> add_sup_distrib_left
  3494     is_join_neg_meet        ~> is_join_neg_inf
  3495     is_meet_neg_join        ~> is_meet_neg_sup
  3496     add_meet_distrib_right  ~> add_inf_distrib_right
  3497     add_join_distrib_right  ~> add_sup_distrib_right
  3498     add_meet_join_distribs  ~> add_sup_inf_distribs
  3499     join_eq_neg_meet        ~> sup_eq_neg_inf
  3500     meet_eq_neg_join        ~> inf_eq_neg_sup
  3501     add_eq_meet_join        ~> add_eq_inf_sup
  3502     meet_0_imp_0            ~> inf_0_imp_0
  3503     join_0_imp_0            ~> sup_0_imp_0
  3504     meet_0_eq_0             ~> inf_0_eq_0
  3505     join_0_eq_0             ~> sup_0_eq_0
  3506     neg_meet_eq_join        ~> neg_inf_eq_sup
  3507     neg_join_eq_meet        ~> neg_sup_eq_inf
  3508     join_eq_if              ~> sup_eq_if
  3509 
  3510     mono_meet               ~> mono_inf
  3511     mono_join               ~> mono_sup
  3512     meet_bool_eq            ~> inf_bool_eq
  3513     join_bool_eq            ~> sup_bool_eq
  3514     meet_fun_eq             ~> inf_fun_eq
  3515     join_fun_eq             ~> sup_fun_eq
  3516     meet_set_eq             ~> inf_set_eq
  3517     join_set_eq             ~> sup_set_eq
  3518     meet1_iff               ~> inf1_iff
  3519     meet2_iff               ~> inf2_iff
  3520     meet1I                  ~> inf1I
  3521     meet2I                  ~> inf2I
  3522     meet1D1                 ~> inf1D1
  3523     meet2D1                 ~> inf2D1
  3524     meet1D2                 ~> inf1D2
  3525     meet2D2                 ~> inf2D2
  3526     meet1E                  ~> inf1E
  3527     meet2E                  ~> inf2E
  3528     join1_iff               ~> sup1_iff
  3529     join2_iff               ~> sup2_iff
  3530     join1I1                 ~> sup1I1
  3531     join2I1                 ~> sup2I1
  3532     join1I1                 ~> sup1I1
  3533     join2I2                 ~> sup1I2
  3534     join1CI                 ~> sup1CI
  3535     join2CI                 ~> sup2CI
  3536     join1E                  ~> sup1E
  3537     join2E                  ~> sup2E
  3538 
  3539     is_meet_Meet            ~> is_meet_Inf
  3540     Meet_bool_def           ~> Inf_bool_def
  3541     Meet_fun_def            ~> Inf_fun_def
  3542     Meet_greatest           ~> Inf_greatest
  3543     Meet_lower              ~> Inf_lower
  3544     Meet_set_def            ~> Inf_set_def
  3545 
  3546     Sup_def                 ~> Sup_Inf
  3547     Sup_bool_eq             ~> Sup_bool_def
  3548     Sup_fun_eq              ~> Sup_fun_def
  3549     Sup_set_eq              ~> Sup_set_def
  3550 
  3551     listsp_meetI            ~> listsp_infI
  3552     listsp_meet_eq          ~> listsp_inf_eq
  3553 
  3554     meet_min                ~> inf_min
  3555     join_max                ~> sup_max
  3556 
  3557 * Added syntactic class "size"; overloaded constant "size" now has
  3558 type "'a::size ==> bool"
  3559 
  3560 * Internal reorganisation of `size' of datatypes: size theorems
  3561 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3562 simplification rules by default!); theorems "prod.size" now named
  3563 "*.size".
  3564 
  3565 * Class "div" now inherits from class "times" rather than "type".
  3566 INCOMPATIBILITY.
  3567 
  3568 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3569 Linorder etc.  have disappeared; operations defined in terms of
  3570 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3571 
  3572 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3573 
  3574 * HOL-Word: New extensive library and type for generic, fixed size
  3575 machine words, with arithemtic, bit-wise, shifting and rotating
  3576 operations, reflection into int, nat, and bool lists, automation for
  3577 linear arithmetic (by automatic reflection into nat or int), including
  3578 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3579 arithmetic type classes, supporting automatic simplification of
  3580 numerals on all operations.
  3581 
  3582 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3583 
  3584 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3585 
  3586 * Code generator library theories:
  3587   - Code_Integer represents HOL integers by big integer literals in target
  3588     languages.
  3589   - Code_Char represents HOL characters by character literals in target
  3590     languages.
  3591   - Code_Char_chr like Code_Char, but also offers treatment of character
  3592     codes; includes Code_Integer.
  3593   - Executable_Set allows to generate code for finite sets using lists.
  3594   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3595     denominator).
  3596   - Executable_Real implements a subset of real numbers, namly those
  3597     representable by rational numbers.
  3598   - Efficient_Nat implements natural numbers by integers, which in general will
  3599     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3600     includes Code_Integer.
  3601   - Code_Index provides an additional datatype index which is mapped to
  3602     target-language built-in integers.
  3603   - Code_Message provides an additional datatype message_string which is isomorphic to
  3604     strings; messages are mapped to target-language strings.
  3605 
  3606 * New package for inductive predicates
  3607 
  3608   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3609 
  3610     inductive
  3611       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3612       for z_1 :: U_1 and ... and z_n :: U_m
  3613     where
  3614       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3615     | ...
  3616 
  3617   with full support for type-inference, rather than
  3618 
  3619     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3620 
  3621     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3622     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3623 
  3624     inductive "s z_1 ... z_m"
  3625     intros
  3626       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3627       ...
  3628 
  3629   For backward compatibility, there is a wrapper allowing inductive
  3630   sets to be defined with the new package via
  3631 
  3632     inductive_set
  3633       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3634       for z_1 :: U_1 and ... and z_n :: U_m
  3635     where
  3636       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3637     | ...
  3638 
  3639   or
  3640 
  3641     inductive_set
  3642       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3643       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3644       for z_1 :: U_1 and ... and z_n :: U_m
  3645     where
  3646       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3647     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3648     | ...
  3649 
  3650   if the additional syntax "p ..." is required.
  3651 
  3652   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3653   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3654 
  3655   INCOMPATIBILITIES:
  3656 
  3657   - Since declaration and definition of inductive sets or predicates
  3658     is no longer separated, abbreviations involving the newly
  3659     introduced sets or predicates must be specified together with the
  3660     introduction rules after the 'where' keyword (see above), rather
  3661     than before the actual inductive definition.
  3662 
  3663   - The variables in induction and elimination rules are now
  3664     quantified in the order of their occurrence in the introduction
  3665     rules, rather than in alphabetical order. Since this may break
  3666     some proofs, these proofs either have to be repaired, e.g. by
  3667     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3668     statements of the form
  3669 
  3670       case (rule_i a_i_1 ... a_i_{k_i})
  3671 
  3672     or the old order of quantification has to be restored by explicitly adding
  3673     meta-level quantifiers in the introduction rules, i.e.
  3674 
  3675       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3676 
  3677   - The format of the elimination rules is now
  3678 
  3679       p z_1 ... z_m x_1 ... x_n ==>
  3680         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3681         ==> ... ==> P
  3682 
  3683     for predicates and
  3684 
  3685       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3686         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3687         ==> ... ==> P
  3688 
  3689     for sets rather than
  3690 
  3691       x : s z_1 ... z_m ==>
  3692         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3693         ==> ... ==> P
  3694 
  3695     This may require terms in goals to be expanded to n-tuples
  3696     (e.g. using case_tac or simplification with the split_paired_all
  3697     rule) before the above elimination rule is applicable.
  3698 
  3699   - The elimination or case analysis rules for (mutually) inductive
  3700     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3701     list of rules "p_1_..._p_k.elims" is no longer available.
  3702 
  3703 * New package "function"/"fun" for general recursive functions,
  3704 supporting mutual and nested recursion, definitions in local contexts,
  3705 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3706 for small examples, and the separate tutorial on the function
  3707 package. The old recdef "package" is still available as before, but
  3708 users are encouraged to use the new package.
  3709 
  3710 * Method "lexicographic_order" automatically synthesizes termination
  3711 relations as lexicographic combinations of size measures. 
  3712 
  3713 * Case-expressions allow arbitrary constructor-patterns (including
  3714 "_") and take their order into account, like in functional
  3715 programming.  Internally, this is translated into nested
  3716 case-expressions; missing cases are added and mapped to the predefined
  3717 constant "undefined". In complicated cases printing may no longer show
  3718 the original input but the internal form. Lambda-abstractions allow
  3719 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3720 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3721 variable.
  3722 
  3723 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3724 is an abbreviation for "of_nat :: nat => int". The simplification
  3725 rules for "of_nat" have been changed to work like "int" did
  3726 previously.  Potential INCOMPATIBILITY:
  3727   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3728   - of_nat_diff and of_nat_mult are no longer default simp rules
  3729 
  3730 * Method "algebra" solves polynomial equations over (semi)rings using
  3731 Groebner bases. The (semi)ring structure is defined by locales and the
  3732 tool setup depends on that generic context. Installing the method for
  3733 a specific type involves instantiating the locale and possibly adding
  3734 declarations for computation on the coefficients.  The method is
  3735 already instantiated for natural numbers and for the axiomatic class
  3736 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3737 CALCULEMUS 2007 for the general principles underlying this
  3738 architecture of context-aware proof-tools.
  3739 
  3740 * Method "ferrack" implements quantifier elimination over
  3741 special-purpose dense linear orders using locales (analogous to
  3742 "algebra"). The method is already installed for class
  3743 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3744 rat, etc.
  3745 
  3746 * Former constant "List.op @" now named "List.append".  Use ML
  3747 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3748 circumvent possible incompatibilities when working on ML level.
  3749 
  3750 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3751 
  3752 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3753 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3754 
  3755 * New syntax for Haskell-like list comprehension (input only), eg.
  3756 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3757 
  3758 * The special syntax for function "filter" has changed from [x :
  3759 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3760 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3761 
  3762 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3763 defined on nat only, as an abbreviation for [a..<Suc b]
  3764 INCOMPATIBILITY.
  3765 
  3766 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3767 
  3768 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3769 
  3770 * New lemma collection field_simps (an extension of ring_simps) for
  3771 manipulating (in)equations involving division. Multiplies with all
  3772 denominators that can be proved to be non-zero (in equations) or
  3773 positive/negative (in inequations).
  3774 
  3775 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3776 have been improved and renamed to ring_simps, group_simps and
  3777 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3778 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3779 
  3780 * Theory Library/Commutative_Ring: switched from recdef to function
  3781 package; constants add, mul, pow now curried.  Infix syntax for
  3782 algebraic operations.
  3783 
  3784 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3785 INCOMPATIBILITY.
  3786 
  3787 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3788 INCOMPATIBILITY.
  3789 
  3790 * HOL/records: generalised field-update to take a function on the
  3791 field rather than the new value: r(|A := x|) is translated to A_update
  3792 (K x) r The K-combinator that is internally used is called K_record.
  3793 INCOMPATIBILITY: Usage of the plain update functions has to be
  3794 adapted.
  3795  
  3796 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3797 * x = 0, which are required for a semiring.  Richer structures do not
  3798 inherit from semiring_0 anymore, because this property is a theorem
  3799 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3800 there is more to prove, but this is mostly trivial.
  3801 
  3802 * Class "recpower" is generalized to arbitrary monoids, not just
  3803 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3804 commutativity or semiring properties additionally.
  3805 
  3806 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3807 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3808 better use 'abbreviation'.
  3809 
  3810 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3811 
  3812 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3813 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3814 significant changes for setting up numeral syntax for types:
  3815   - New constants Numeral.pred and Numeral.succ instead
  3816       of former Numeral.bin_pred and Numeral.bin_succ.
  3817   - Use integer operations instead of bin_add, bin_mult and so on.
  3818   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3819   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3820 
  3821 See src/HOL/Integ/IntArith.thy for an example setup.
  3822 
  3823 * Command 'normal_form' computes the normal form of a term that may
  3824 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3825 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3826 heavy-duty computations because the functions are compiled to ML
  3827 first.  Correspondingly, a method "normalization" is provided.  See
  3828 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3829 
  3830 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3831 25 like -->); output depends on the "iff" print_mode, the default is
  3832 "A = B" (with priority 50).
  3833 
  3834 * Relations less (<) and less_eq (<=) are also available on type bool.
  3835 Modified syntax to disallow nesting without explicit parentheses,
  3836 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3837 INCOMPATIBILITY.
  3838 
  3839 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3840 
  3841 * Relation composition operator "op O" now has precedence 75 and binds
  3842 stronger than union and intersection. INCOMPATIBILITY.
  3843 
  3844 * The old set interval syntax "{m..n(}" (and relatives) has been
  3845 removed.  Use "{m..<n}" (and relatives) instead.
  3846 
  3847 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3848 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3849 ``declare [[simproc del: neq]]''.
  3850 
  3851 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3852 True/False.
  3853 
  3854 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3855 
  3856 * Theorem setsum_mult renamed to setsum_right_distrib.
  3857 
  3858 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3859 ``rule'' method.
  3860 
  3861 * Reimplemented methods "sat" and "satx", with several improvements:
  3862 goals no longer need to be stated as "<prems> ==> False", equivalences
  3863 (i.e. "=" on type bool) are handled, variable names of the form
  3864 "lit_<n>" are no longer reserved, significant speedup.
  3865 
  3866 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3867 zChaff is still supported as well.
  3868 
  3869 * 'inductive' and 'datatype': provide projections of mutual rules,
  3870 bundled as foo_bar.inducts;
  3871 
  3872 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3873 Library.
  3874 
  3875 * Library: moved theory Accessible_Part to main HOL.
  3876 
  3877 * Library: added theory Coinductive_List of potentially infinite lists
  3878 as greatest fixed-point.
  3879 
  3880 * Library: added theory AssocList which implements (finite) maps as
  3881 association lists.
  3882 
  3883 * Method "evaluation" solves goals (i.e. a boolean expression)
  3884 efficiently by compiling it to ML.  The goal is "proved" (via an
  3885 oracle) if it evaluates to True.
  3886 
  3887 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3888 also when invoked by the simplifier.  This results in the Simplifier
  3889 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3890 Configuration option fast_arith_split_limit=0 recovers the old
  3891 behavior.
  3892 
  3893 * Support for hex (0x20) and binary (0b1001) numerals.
  3894 
  3895 * New method: reify eqs (t), where eqs are equations for an
  3896 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3897 parameter, computes a term s::'b and a list xs::'a list and proves the
  3898 theorem I xs s = t. This is also known as reification or quoting. The
  3899 resulting theorem is applied to the subgoal to substitute t with I xs
  3900 s.  If t is omitted, the subgoal itself is reified.
  3901 
  3902 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3903 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3904 where f is supposed to be a computable function (in the sense of code
  3905 generattion). The method uses reify to compute s and xs as above then
  3906 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3907 r and finally gets the theorem t = r, which is again applied to the
  3908 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3909 
  3910 * Reflection: Automatic reification now handels binding, an example is
  3911 available in src/HOL/ex/ReflectionEx.thy
  3912 
  3913 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3914 command 'statespace' that is similar to 'record', but introduces an
  3915 abstract specification based on the locale infrastructure instead of
  3916 HOL types.  This leads to extra flexibility in composing state spaces,
  3917 in particular multiple inheritance and renaming of components.
  3918 
  3919 
  3920 *** HOL-Complex ***
  3921 
  3922 * Hyperreal: Functions root and sqrt are now defined on negative real
  3923 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3924 Nonnegativity side conditions have been removed from many lemmas, so
  3925 that more subgoals may now be solved by simplification; potential
  3926 INCOMPATIBILITY.
  3927 
  3928 * Real: new type classes formalize real normed vector spaces and
  3929 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3930 and norm :: 'a => real.
  3931 
  3932 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3933 reals into other types. The overloaded constant Reals :: 'a set is now
  3934 defined as range of_real; potential INCOMPATIBILITY.
  3935 
  3936 * Real: proper support for ML code generation, including 'quickcheck'.
  3937 Reals are implemented as arbitrary precision rationals.
  3938 
  3939 * Hyperreal: Several constants that previously worked only for the
  3940 reals have been generalized, so they now work over arbitrary vector
  3941 spaces. Type annotations may need to be added in some cases; potential
  3942 INCOMPATIBILITY.
  3943 
  3944   Infinitesimal  :: ('a::real_normed_vector) star set
  3945   HFinite        :: ('a::real_normed_vector) star set
  3946   HInfinite      :: ('a::real_normed_vector) star set
  3947   approx         :: ('a::real_normed_vector) star => 'a star => bool
  3948   monad          :: ('a::real_normed_vector) star => 'a star set
  3949   galaxy         :: ('a::real_normed_vector) star => 'a star set
  3950   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  3951   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  3952   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  3953   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  3954   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  3955   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  3956   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  3957   sgn            :: 'a::real_normed_vector => 'a
  3958   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  3959 
  3960 * Complex: Some complex-specific constants are now abbreviations for
  3961 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  3962 hnorm.  Other constants have been entirely removed in favor of the
  3963 polymorphic versions (INCOMPATIBILITY):
  3964 
  3965   approx        <-- capprox
  3966   HFinite       <-- CFinite
  3967   HInfinite     <-- CInfinite
  3968   Infinitesimal <-- CInfinitesimal
  3969   monad         <-- cmonad
  3970   galaxy        <-- cgalaxy
  3971   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  3972   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  3973   (ns)deriv     <-- (ns)cderiv
  3974 
  3975 
  3976 *** HOL-Algebra ***
  3977 
  3978 * Formalisation of ideals and the quotient construction over rings.
  3979 
  3980 * Order and lattice theory no longer based on records.
  3981 INCOMPATIBILITY.
  3982 
  3983 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  3984 greatest_closed.  INCOMPATIBILITY.
  3985 
  3986 * Method algebra is now set up via an attribute.  For examples see
  3987 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  3988 of algebraic structures.
  3989 
  3990 * Renamed theory CRing to Ring.
  3991 
  3992 
  3993 *** HOL-Nominal ***
  3994 
  3995 * Substantial, yet incomplete support for nominal datatypes (binding
  3996 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3997 src/HOL/Nominal/Examples.  Prospective users should consult
  3998 http://isabelle.in.tum.de/nominal/
  3999 
  4000 
  4001 *** ML ***
  4002 
  4003 * ML basics: just one true type int, which coincides with IntInf.int
  4004 (even on SML/NJ).
  4005 
  4006 * ML within Isar: antiquotations allow to embed statically-checked
  4007 formal entities in the source, referring to the context available at
  4008 compile-time.  For example:
  4009 
  4010 ML {* @{sort "{zero,one}"} *}
  4011 ML {* @{typ "'a => 'b"} *}
  4012 ML {* @{term "%x. x"} *}
  4013 ML {* @{prop "x == y"} *}
  4014 ML {* @{ctyp "'a => 'b"} *}
  4015 ML {* @{cterm "%x. x"} *}
  4016 ML {* @{cprop "x == y"} *}
  4017 ML {* @{thm asm_rl} *}
  4018 ML {* @{thms asm_rl} *}
  4019 ML {* @{type_name c} *}
  4020 ML {* @{type_syntax c} *}
  4021 ML {* @{const_name c} *}
  4022 ML {* @{const_syntax c} *}
  4023 ML {* @{context} *}
  4024 ML {* @{theory} *}
  4025 ML {* @{theory Pure} *}
  4026 ML {* @{theory_ref} *}
  4027 ML {* @{theory_ref Pure} *}
  4028 ML {* @{simpset} *}
  4029 ML {* @{claset} *}
  4030 ML {* @{clasimpset} *}
  4031 
  4032 The same works for sources being ``used'' within an Isar context.
  4033 
  4034 * ML in Isar: improved error reporting; extra verbosity with
  4035 ML_Context.trace enabled.
  4036 
  4037 * Pure/General/table.ML: the join operations now works via exceptions
  4038 DUP/SAME instead of type option. This is simpler in simple cases, and
  4039 admits slightly more efficient complex applications.
  4040 
  4041 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4042 use Context.generic instead of just theory.
  4043 
  4044 * Pure: datatype Context.generic joins theory/Proof.context and
  4045 provides some facilities for code that works in either kind of
  4046 context, notably GenericDataFun for uniform theory and proof data.
  4047 
  4048 * Pure: simplified internal attribute type, which is now always
  4049 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4050 local (Proof.context) attributes have been discontinued, while
  4051 minimizing code duplication. Thm.rule_attribute and
  4052 Thm.declaration_attribute build canonical attributes; see also structure
  4053 Context for further operations on Context.generic, notably
  4054 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4055 declarations and definitions.
  4056 
  4057 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4058 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4059 init only required for impure data. INCOMPATIBILITY: empty really need
  4060 to be empty (no dependencies on theory content!)
  4061 
  4062 * Pure/kernel: consts certification ignores sort constraints given in
  4063 signature declarations. (This information is not relevant to the
  4064 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4065 potential INCOMPATIBILITY.
  4066 
  4067 * Pure: axiomatic type classes are now purely definitional, with
  4068 explicit proofs of class axioms and super class relations performed
  4069 internally. See Pure/axclass.ML for the main internal interfaces --
  4070 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4071 AxClass.axiomatize_class/classrel/arity supersede
  4072 Sign.add_classes/classrel/arities.
  4073 
  4074 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4075 global/local versions on theory vs. Proof.context have been
  4076 discontinued; Attrib.syntax and Method.syntax have been adapted
  4077 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4078 attributes, methods, etc.
  4079 
  4080 * Pure: several functions of signature "... -> theory -> theory * ..."
  4081 have been reoriented to "... -> theory -> ... * theory" in order to
  4082 allow natural usage in combination with the ||>, ||>>, |-> and
  4083 fold_map combinators.
  4084 
  4085 * Pure: official theorem names (closed derivations) and additional
  4086 comments (tags) are now strictly separate.  Name hints -- which are
  4087 maintained as tags -- may be attached any time without affecting the
  4088 derivation.
  4089 
  4090 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4091 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4092 achieve the old behaviour.
  4093 
  4094 * Pure: the "Goal" constant is now called "prop", supporting a
  4095 slightly more general idea of ``protecting'' meta-level rule
  4096 statements.
  4097 
  4098 * Pure: Logic.(un)varify only works in a global context, which is now
  4099 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4100 Logic.legacy_(un)varify as temporary workaround.
  4101 
  4102 * Pure: structure Name provides scalable operations for generating
  4103 internal variable names, notably Name.variants etc.  This replaces
  4104 some popular functions from term.ML:
  4105 
  4106   Term.variant		->  Name.variant
  4107   Term.variantlist	->  Name.variant_list
  4108   Term.invent_names	->  Name.invent_list
  4109 
  4110 Note that low-level renaming rarely occurs in new code -- operations
  4111 from structure Variable are used instead (see below).
  4112 
  4113 * Pure: structure Variable provides fundamental operations for proper
  4114 treatment of fixed/schematic variables in a context.  For example,
  4115 Variable.import introduces fixes for schematics of given facts and
  4116 Variable.export reverses the effect (up to renaming) -- this replaces
  4117 various freeze_thaw operations.
  4118 
  4119 * Pure: structure Goal provides simple interfaces for
  4120 init/conclude/finish and tactical prove operations (replacing former
  4121 Tactic.prove).  Goal.prove is the canonical way to prove results
  4122 within a given context; Goal.prove_global is a degraded version for
  4123 theory level goals, including a global Drule.standard.  Note that
  4124 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4125 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4126 in a locale context).
  4127 
  4128 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4129 and type checking (Syntax.check_term etc.), with common combinations
  4130 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4131 which are considered legacy and await removal.
  4132 
  4133 * Pure/Syntax: generic interfaces for type unchecking
  4134 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4135 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4136 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4137 available for convenience, but refer to the very same operations using
  4138 a mere theory instead of a full context.
  4139 
  4140 * Isar: simplified treatment of user-level errors, using exception
  4141 ERROR of string uniformly.  Function error now merely raises ERROR,
  4142 without any side effect on output channels.  The Isar toplevel takes
  4143 care of proper display of ERROR exceptions.  ML code may use plain
  4144 handle/can/try; cat_error may be used to concatenate errors like this:
  4145 
  4146   ... handle ERROR msg => cat_error msg "..."
  4147 
  4148 Toplevel ML code (run directly or through the Isar toplevel) may be
  4149 embedded into the Isar toplevel with exception display/debug like
  4150 this:
  4151 
  4152   Isar.toplevel (fn () => ...)
  4153 
  4154 INCOMPATIBILITY, removed special transform_error facilities, removed
  4155 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4156 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4157 -- use plain ERROR instead.
  4158 
  4159 * Isar: theory setup now has type (theory -> theory), instead of a
  4160 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4161 
  4162 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4163 ProofContext.debug/verbose flags.
  4164 
  4165 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4166 theory before entering a proof state.  Transactions now always see a
  4167 quasi-functional intermediate checkpoint, both in interactive and
  4168 batch mode.
  4169 
  4170 * Isar: simplified interfaces for outer syntax.  Renamed
  4171 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4172 OuterSyntax.add_parsers -- this functionality is now included in
  4173 OuterSyntax.command etc.  INCOMPATIBILITY.
  4174 
  4175 * Simplifier: the simpset of a running simplification process now
  4176 contains a proof context (cf. Simplifier.the_context), which is the
  4177 very context that the initial simpset has been retrieved from (by
  4178 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4179 (solver, looper etc.) may depend on arbitrary proof data.
  4180 
  4181 * Simplifier.inherit_context inherits the proof context (plus the
  4182 local bounds) of the current simplification process; any simproc
  4183 etc. that calls the Simplifier recursively should do this!  Removed
  4184 former Simplifier.inherit_bounds, which is already included here --
  4185 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4186 specify an explicit context using Simplifier.context/theory_context.
  4187 
  4188 * Simplifier/Classical Reasoner: more abstract interfaces
  4189 change_simpset/claset for modifying the simpset/claset reference of a
  4190 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4191 INCOMPATIBILITY.
  4192 
  4193 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4194 "Trueprop" etc.
  4195 
  4196 
  4197 *** System ***
  4198 
  4199 * settings: the default heap location within ISABELLE_HOME_USER now
  4200 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4201 Isabelle installations.
  4202 
  4203 * isabelle-process: option -S (secure mode) disables some critical
  4204 operations, notably runtime compilation and evaluation of ML source
  4205 code.
  4206 
  4207 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4208 
  4209 * Support for parallel execution, using native multicore support of
  4210 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4211 independent theories, according to the given theory header
  4212 specifications. The maximum number of worker threads is specified via
  4213 usedir option -M or the "max-threads" setting in Proof General. A
  4214 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4215 to 6 on a 8-core machine.  User-code needs to observe certain
  4216 guidelines for thread-safe programming, see appendix A in the Isar
  4217 Implementation manual.
  4218 
  4219 
  4220 
  4221 New in Isabelle2005 (October 2005)
  4222 ----------------------------------
  4223 
  4224 *** General ***
  4225 
  4226 * Theory headers: the new header syntax for Isar theories is
  4227 
  4228   theory <name>
  4229   imports <theory1> ... <theoryN>
  4230   uses <file1> ... <fileM>
  4231   begin
  4232 
  4233 where the 'uses' part is optional.  The previous syntax
  4234 
  4235   theory <name> = <theory1> + ... + <theoryN>:
  4236 
  4237 will disappear in the next release.  Use isatool fixheaders to convert
  4238 existing theory files.  Note that there is no change in ancient
  4239 non-Isar theories now, but these will disappear soon.
  4240 
  4241 * Theory loader: parent theories can now also be referred to via
  4242 relative and absolute paths.
  4243 
  4244 * Command 'find_theorems' searches for a list of criteria instead of a
  4245 list of constants. Known criteria are: intro, elim, dest, name:string,
  4246 simp:term, and any term. Criteria can be preceded by '-' to select
  4247 theorems that do not match. Intro, elim, dest select theorems that
  4248 match the current goal, name:s selects theorems whose fully qualified
  4249 name contain s, and simp:term selects all simplification rules whose
  4250 lhs match term.  Any other term is interpreted as pattern and selects
  4251 all theorems matching the pattern. Available in ProofGeneral under
  4252 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4253 
  4254   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4255 
  4256 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4257 matching the current goal as introduction rule and not having "HOL."
  4258 in their name (i.e. not being defined in theory HOL).
  4259 
  4260 * Command 'thms_containing' has been discontinued in favour of
  4261 'find_theorems'; INCOMPATIBILITY.
  4262 
  4263 * Communication with Proof General is now 8bit clean, which means that
  4264 Unicode text in UTF-8 encoding may be used within theory texts (both
  4265 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4266 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4267 
  4268   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4269   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4270 
  4271 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4272 Classical Reasoner.  Typical big applications run around 2 times
  4273 faster.
  4274 
  4275 
  4276 *** Document preparation ***
  4277 
  4278 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4279 of raw sources.  Only those symbols that do not require additional
  4280 LaTeX packages (depending on comments in isabellesym.sty) are
  4281 displayed properly, everything else is left verbatim.  isatool display
  4282 and isatool print are used as front ends (these are subject to the
  4283 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4284 
  4285 * Command tags control specific markup of certain regions of text,
  4286 notably folding and hiding.  Predefined tags include "theory" (for
  4287 theory begin and end), "proof" for proof commands, and "ML" for
  4288 commands involving ML code; the additional tags "visible" and
  4289 "invisible" are unused by default.  Users may give explicit tag
  4290 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4291 interpretation of tags is determined by the LaTeX job during document
  4292 preparation: see option -V of isatool usedir, or options -n and -t of
  4293 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4294 \isadroptag.
  4295 
  4296 Several document versions may be produced at the same time via isatool
  4297 usedir (the generated index.html will link all of them).  Typical
  4298 specifications include ''-V document=theory,proof,ML'' to present
  4299 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4300 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4301 these parts without any formal replacement text.  The Isabelle site
  4302 default settings produce ''document'' and ''outline'' versions as
  4303 specified above.
  4304 
  4305 * Several new antiquotations:
  4306 
  4307   @{term_type term} prints a term with its type annotated;
  4308 
  4309   @{typeof term} prints the type of a term;
  4310 
  4311   @{const const} is the same as @{term const}, but checks that the
  4312   argument is a known logical constant;
  4313 
  4314   @{term_style style term} and @{thm_style style thm} print a term or
  4315   theorem applying a "style" to it
  4316 
  4317   @{ML text}
  4318 
  4319 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4320 definitions, equations, inequations etc., 'concl' printing only the
  4321 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4322 to print the specified premise.  TermStyle.add_style provides an ML
  4323 interface for introducing further styles.  See also the "LaTeX Sugar"
  4324 document practical applications.  The ML antiquotation prints
  4325 type-checked ML expressions verbatim.
  4326 
  4327 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4328 and 'text' support optional locale specification '(in loc)', which
  4329 specifies the default context for interpreting antiquotations.  For
  4330 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4331 
  4332 * Option 'locale=NAME' of antiquotations specifies an alternative
  4333 context interpreting the subsequent argument.  For example: @{thm
  4334 [locale=lattice] inf_assoc}.
  4335 
  4336 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4337 a proof context.
  4338 
  4339 * Proper output of antiquotations for theory commands involving a
  4340 proof context (such as 'locale' or 'theorem (in loc) ...').
  4341 
  4342 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4343 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4344 
  4345 * isatool usedir: new option -C (default true) controls whether option
  4346 -D should include a copy of the original document directory; -C false
  4347 prevents unwanted effects such as copying of administrative CVS data.
  4348 
  4349 
  4350 *** Pure ***
  4351 
  4352 * Considerably improved version of 'constdefs' command.  Now performs
  4353 automatic type-inference of declared constants; additional support for
  4354 local structure declarations (cf. locales and HOL records), see also
  4355 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4356 sequential dependencies of definitions within a single 'constdefs'
  4357 section; moreover, the declared name needs to be an identifier.  If
  4358 all fails, consider to fall back on 'consts' and 'defs' separately.
  4359 
  4360 * Improved indexed syntax and implicit structures.  First of all,
  4361 indexed syntax provides a notational device for subscripted
  4362 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4363 expressions.  Secondly, in a local context with structure
  4364 declarations, number indexes \<^sub>n or the empty index (default
  4365 number 1) refer to a certain fixed variable implicitly; option
  4366 show_structs controls printing of implicit structures.  Typical
  4367 applications of these concepts involve record types and locales.
  4368 
  4369 * New command 'no_syntax' removes grammar declarations (and
  4370 translations) resulting from the given syntax specification, which is
  4371 interpreted in the same manner as for the 'syntax' command.
  4372 
  4373 * 'Advanced' translation functions (parse_translation etc.) may depend
  4374 on the signature of the theory context being presently used for
  4375 parsing/printing, see also isar-ref manual.
  4376 
  4377 * Improved 'oracle' command provides a type-safe interface to turn an
  4378 ML expression of type theory -> T -> term into a primitive rule of
  4379 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4380 is already included here); see also FOL/ex/IffExample.thy;
  4381 INCOMPATIBILITY.
  4382 
  4383 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4384 before); "cI" is no longer bound, use "c.intro" instead.
  4385 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4386 axclasses vs. locales.
  4387 
  4388 * Improved internal renaming of symbolic identifiers -- attach primes
  4389 instead of base 26 numbers.
  4390 
  4391 * New flag show_question_marks controls printing of leading question
  4392 marks in schematic variable names.
  4393 
  4394 * In schematic variable names, *any* symbol following \<^isub> or
  4395 \<^isup> is now treated as part of the base name.  For example, the
  4396 following works without printing of awkward ".0" indexes:
  4397 
  4398   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4399     by simp
  4400 
  4401 * Inner syntax includes (*(*nested*) comments*).
  4402 
  4403 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4404 annotations as "(00...)".
  4405 
  4406 * Clear separation of logical types and nonterminals, where the latter
  4407 may only occur in 'syntax' specifications or type abbreviations.
  4408 Before that distinction was only partially implemented via type class
  4409 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4410 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4411 exotic syntax specifications may require further adaption
  4412 (e.g. Cube/Cube.thy).
  4413 
  4414 * Removed obsolete type class "logic", use the top sort {} instead.
  4415 Note that non-logical types should be declared as 'nonterminals'
  4416 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4417 specifications.
  4418 
  4419 * Attributes 'induct' and 'cases': type or set names may now be
  4420 locally fixed variables as well.
  4421 
  4422 * Simplifier: can now control the depth to which conditional rewriting
  4423 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4424 Limit.
  4425 
  4426 * Simplifier: simplification procedures may now take the current
  4427 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4428 interface), which is very useful for calling the Simplifier
  4429 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4430 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4431 low-level mk_simproc no longer applies Logic.varify internally, to
  4432 allow for use in a context of fixed variables.
  4433 
  4434 * thin_tac now works even if the assumption being deleted contains !!
  4435 or ==>.  More generally, erule now works even if the major premise of
  4436 the elimination rule contains !! or ==>.
  4437 
  4438 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4439 
  4440 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4441 from Pure, which contains all common declarations already.  Both
  4442 theories are defined via plain Isabelle/Isar .thy files.
  4443 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4444 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4445 use isatool fixcpure to adapt your theory and ML sources.
  4446 
  4447 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4448 selections of theorems in named facts via index ranges.
  4449 
  4450 * 'print_theorems': in theory mode, really print the difference
  4451 wrt. the last state (works for interactive theory development only),
  4452 in proof mode print all local facts (cf. 'print_facts');
  4453 
  4454 * 'hide': option '(open)' hides only base names.
  4455 
  4456 * More efficient treatment of intermediate checkpoints in interactive
  4457 theory development.
  4458 
  4459 * Code generator is now invoked via code_module (incremental code
  4460 generation) and code_library (modular code generation, ML structures
  4461 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4462 must be quoted when used as identifiers.
  4463 
  4464 * New 'value' command for reading, evaluating and printing terms using
  4465 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4466 quoted when used as identifier.
  4467 
  4468 
  4469 *** Locales ***
  4470 
  4471 * New commands for the interpretation of locale expressions in
  4472 theories (1), locales (2) and proof contexts (3).  These generate
  4473 proof obligations from the expression specification.  After the
  4474 obligations have been discharged, theorems of the expression are added
  4475 to the theory, target locale or proof context.  The synopsis of the
  4476 commands is a follows:
  4477 
  4478   (1) interpretation expr inst
  4479   (2) interpretation target < expr
  4480   (3) interpret expr inst
  4481 
  4482 Interpretation in theories and proof contexts require a parameter
  4483 instantiation of terms from the current context.  This is applied to
  4484 specifications and theorems of the interpreted expression.
  4485 Interpretation in locales only permits parameter renaming through the
  4486 locale expression.  Interpretation is smart in that interpretations
  4487 that are active already do not occur in proof obligations, neither are
  4488 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4489 inspect active interpretations of a particular locale.  For details,
  4490 see the Isar Reference manual.  Examples can be found in
  4491 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4492 
  4493 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4494 'interpret' instead.
  4495 
  4496 * New context element 'constrains' for adding type constraints to
  4497 parameters.
  4498 
  4499 * Context expressions: renaming of parameters with syntax
  4500 redeclaration.
  4501 
  4502 * Locale declaration: 'includes' disallowed.
  4503 
  4504 * Proper static binding of attribute syntax -- i.e. types / terms /
  4505 facts mentioned as arguments are always those of the locale definition
  4506 context, independently of the context of later invocations.  Moreover,
  4507 locale operations (renaming and type / term instantiation) are applied
  4508 to attribute arguments as expected.
  4509 
  4510 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4511 actual attributes; rare situations may require Attrib.attribute to
  4512 embed those attributes into Attrib.src that lack concrete syntax.
  4513 Attribute implementations need to cooperate properly with the static
  4514 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4515 Attrib.XXX_thm etc. already do the right thing without further
  4516 intervention.  Only unusual applications -- such as "where" or "of"
  4517 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4518 on the context and the facts involved -- may have to assign parsed
  4519 values to argument tokens explicitly.
  4520 
  4521 * Changed parameter management in theorem generation for long goal
  4522 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4523 theorem statement in rare situations.
  4524 
  4525 * Locale inspection command 'print_locale' omits notes elements.  Use
  4526 'print_locale!' to have them included in the output.
  4527 
  4528 
  4529 *** Provers ***
  4530 
  4531 * Provers/hypsubst.ML: improved version of the subst method, for
  4532 single-step rewriting: it now works in bound variable contexts. New is
  4533 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4534 rewrite a different subterm than the original subst method, which is
  4535 still available as 'simplesubst'.
  4536 
  4537 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4538 and quasi orders.
  4539 
  4540 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4541 reflexive-transitive closure of relations.
  4542 
  4543 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4544 limit (previously hard-coded with a value of 20) user-definable.
  4545 
  4546 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4547 is peformed already.  Object-logics merely need to finish their
  4548 initial simpset configuration as before.  INCOMPATIBILITY.
  4549 
  4550 
  4551 *** HOL ***
  4552 
  4553 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4554 
  4555   syntax (epsilon)
  4556     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4557 
  4558 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4559 and x-symbol; use option '-m epsilon' to get it actually printed.
  4560 Moreover, the mathematically important symbolic identifier \<epsilon>
  4561 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4562 
  4563 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4564 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4565 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4566 support corresponding Isar calculations.
  4567 
  4568 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4569 instead of ":".
  4570 
  4571 * theory SetInterval: changed the syntax for open intervals:
  4572 
  4573   Old       New
  4574   {..n(}    {..<n}
  4575   {)n..}    {n<..}
  4576   {m..n(}   {m..<n}
  4577   {)m..n}   {m<..n}
  4578   {)m..n(}  {m<..<n}
  4579 
  4580 The old syntax is still supported but will disappear in the next
  4581 release.  For conversion use the following Emacs search and replace
  4582 patterns (these are not perfect but work quite well):
  4583 
  4584   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4585   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4586 
  4587 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4588 equalities in commutative rings; method 'algebra' provides a generic
  4589 interface.
  4590 
  4591 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4592 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4593 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4594 be a tuple pattern.
  4595 
  4596 Some new syntax forms are available:
  4597 
  4598   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4599   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4600   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4601   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4602 
  4603 The latter form "\<Sum>x < k. e" used to be based on a separate
  4604 function "Summation", which has been discontinued.
  4605 
  4606 * theory Finite_Set: in structured induction proofs, the insert case
  4607 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4608 (insert F x)'.
  4609 
  4610 * The 'refute' command has been extended to support a much larger
  4611 fragment of HOL, including axiomatic type classes, constdefs and
  4612 typedefs, inductive datatypes and recursion.
  4613 
  4614 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4615 Requires zChaff with proof generation to be installed.  See
  4616 HOL/ex/SAT_Examples.thy for examples.
  4617 
  4618 * Datatype induction via method 'induct' now preserves the name of the
  4619 induction variable. For example, when proving P(xs::'a list) by
  4620 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4621 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4622 in unstructured proof scripts.
  4623 
  4624 * Reworked implementation of records.  Improved scalability for
  4625 records with many fields, avoiding performance problems for type
  4626 inference. Records are no longer composed of nested field types, but
  4627 of nested extension types. Therefore the record type only grows linear
  4628 in the number of extensions and not in the number of fields.  The
  4629 top-level (users) view on records is preserved.  Potential
  4630 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4631 old record representation. The type generated for a record is called
  4632 <record_name>_ext_type.
  4633 
  4634 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4635 proofs triggered by a record definition or a simproc (if
  4636 quick_and_dirty is enabled).  Definitions of large records can take
  4637 quite long.
  4638 
  4639 New simproc record_upd_simproc for simplification of multiple record
  4640 updates enabled by default.  Moreover, trivial updates are also
  4641 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4642 occasionally, since simplification is more powerful by default.
  4643 
  4644 * typedef: proper support for polymorphic sets, which contain extra
  4645 type-variables in the term.
  4646 
  4647 * Simplifier: automatically reasons about transitivity chains
  4648 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4649 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4650 old proofs break occasionally as simplification may now solve more
  4651 goals than previously.
  4652 
  4653 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4654 present.  Works for all partial orders (class "order"), in particular
  4655 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4656 just like y <= x.
  4657 
  4658 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4659 bound variable or a constant then the let is unfolded.  Otherwise
  4660 first a is simplified to b, and then f b is simplified to g. If
  4661 possible we abstract b from g arriving at "let x = b in h x",
  4662 otherwise we unfold the let and arrive at g.  The simproc can be
  4663 enabled/disabled by the reference use_let_simproc.  Potential
  4664 INCOMPATIBILITY since simplification is more powerful by default.
  4665 
  4666 * Classical reasoning: the meson method now accepts theorems as arguments.
  4667 
  4668 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4669 jobs to provide advice on the provability of subgoals.
  4670 
  4671 * Theory OrderedGroup and Ring_and_Field: various additions and
  4672 improvements to faciliate calculations involving equalities and
  4673 inequalities.
  4674 
  4675 The following theorems have been eliminated or modified
  4676 (INCOMPATIBILITY):
  4677 
  4678   abs_eq             now named abs_of_nonneg
  4679   abs_of_ge_0        now named abs_of_nonneg
  4680   abs_minus_eq       now named abs_of_nonpos
  4681   imp_abs_id         now named abs_of_nonneg
  4682   imp_abs_neg_id     now named abs_of_nonpos
  4683   mult_pos           now named mult_pos_pos
  4684   mult_pos_le        now named mult_nonneg_nonneg
  4685   mult_pos_neg_le    now named mult_nonneg_nonpos
  4686   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4687   mult_neg           now named mult_neg_neg
  4688   mult_neg_le        now named mult_nonpos_nonpos
  4689 
  4690 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4691      
  4692      zero_le_square
  4693      not_square_less_zero 
  4694 
  4695   The following lemmas have been deleted from Real/RealPow:
  4696   
  4697      realpow_zero_zero
  4698      realpow_two
  4699      realpow_less
  4700      zero_le_power
  4701      realpow_two_le
  4702      abs_realpow_two
  4703      realpow_two_abs     
  4704 
  4705 * Theory Parity: added rules for simplifying exponents.
  4706 
  4707 * Theory List:
  4708 
  4709 The following theorems have been eliminated or modified
  4710 (INCOMPATIBILITY):
  4711 
  4712   list_all_Nil       now named list_all.simps(1)
  4713   list_all_Cons      now named list_all.simps(2)
  4714   list_all_conv      now named list_all_iff
  4715   set_mem_eq         now named mem_iff
  4716 
  4717 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4718 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4719 
  4720 
  4721 *** HOL-Complex ***
  4722 
  4723 * Theory RealDef: better support for embedding natural numbers and
  4724 integers in the reals.
  4725 
  4726 The following theorems have been eliminated or modified
  4727 (INCOMPATIBILITY):
  4728 
  4729   exp_ge_add_one_self  now requires no hypotheses
  4730   real_of_int_add      reversed direction of equality (use [symmetric])
  4731   real_of_int_minus    reversed direction of equality (use [symmetric])
  4732   real_of_int_diff     reversed direction of equality (use [symmetric])
  4733   real_of_int_mult     reversed direction of equality (use [symmetric])
  4734 
  4735 * Theory RComplete: expanded support for floor and ceiling functions.
  4736 
  4737 * Theory Ln is new, with properties of the natural logarithm
  4738 
  4739 * Hyperreal: There is a new type constructor "star" for making
  4740 nonstandard types.  The old type names are now type synonyms:
  4741 
  4742   hypreal = real star
  4743   hypnat = nat star
  4744   hcomplex = complex star
  4745 
  4746 * Hyperreal: Many groups of similarly-defined constants have been
  4747 replaced by polymorphic versions (INCOMPATIBILITY):
  4748 
  4749   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4750 
  4751   starset      <-- starsetNat, starsetC
  4752   *s*          <-- *sNat*, *sc*
  4753   starset_n    <-- starsetNat_n, starsetC_n
  4754   *sn*         <-- *sNatn*, *scn*
  4755   InternalSets <-- InternalNatSets, InternalCSets
  4756 
  4757   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4758   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4759   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4760   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4761   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4762 
  4763 * Hyperreal: Many type-specific theorems have been removed in favor of
  4764 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4765 
  4766   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4767   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4768   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4769   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4770   right_minus <-- hypreal_add_minus
  4771   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4772   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4773   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4774   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4775   mult_1_right <-- hcomplex_mult_one_right
  4776   mult_zero_left <-- hcomplex_mult_zero_left
  4777   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4778   right_distrib <-- hypnat_add_mult_distrib2
  4779   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4780   right_inverse <-- hypreal_mult_inverse
  4781   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4782   order_refl <-- {hypreal,hypnat}_le_refl
  4783   order_trans <-- {hypreal,hypnat}_le_trans
  4784   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4785   order_less_le <-- {hypreal,hypnat}_less_le
  4786   linorder_linear <-- {hypreal,hypnat}_le_linear
  4787   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4788   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4789   add_nonneg_nonneg <-- hypreal_le_add_order
  4790 
  4791 * Hyperreal: Separate theorems having to do with type-specific
  4792 versions of constants have been merged into theorems that apply to the
  4793 new polymorphic constants (INCOMPATIBILITY):
  4794 
  4795   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4796   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4797   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4798   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4799   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4800   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4801   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4802   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4803   STAR_diff <-- {STAR,STARC}_diff
  4804   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4805     STARC_hcomplex_of_complex}_image_subset
  4806   starset_n_Un <-- starset{Nat,C}_n_Un
  4807   starset_n_Int <-- starset{Nat,C}_n_Int
  4808   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4809   starset_n_diff <-- starset{Nat,C}_n_diff
  4810   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4811   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4812   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4813   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4814   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4815   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4816   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4817   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4818   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4819   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4820   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4821   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4822   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4823   starfun_diff <-- starfun{C,RC,CR}_diff
  4824   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4825   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4826   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4827   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4828   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4829   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4830   starfun_Id <-- starfunC_Id
  4831   starfun_approx <-- starfun{Nat,CR}_approx
  4832   starfun_capprox <-- starfun{C,RC}_capprox
  4833   starfun_abs <-- starfunNat_rabs
  4834   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4835   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4836   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4837   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4838   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4839   starfun_add_approx <-- starfunCR_add_approx
  4840   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4841   starfun_divide <-- starfun{C,CR,RC}_divide
  4842   starfun_n <-- starfun{Nat,C}_n
  4843   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4844   starfun_n_add <-- starfun{Nat,C}_n_add
  4845   starfun_n_add_minus <-- starfunNat_n_add_minus
  4846   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4847   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4848   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4849 
  4850   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4851   star_n_minus <-- {hypreal,hcomplex}_minus
  4852   star_n_diff <-- {hypreal,hcomplex}_diff
  4853   star_n_mult <-- {hypreal,hcomplex}_mult
  4854   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4855   star_n_le <-- {hypreal,hypnat}_le
  4856   star_n_less <-- {hypreal,hypnat}_less
  4857   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4858   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4859   star_n_abs <-- hypreal_hrabs
  4860   star_n_divide <-- hcomplex_divide
  4861 
  4862   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4863   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4864   star_of_diff <-- hypreal_of_real_diff
  4865   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4866   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4867   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4868   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4869   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4870   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4871   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4872   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4873   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4874   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4875   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4876   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4877   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4878   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4879   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4880   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4881   star_of_power <-- hypreal_of_real_power
  4882   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4883 
  4884 * Hyperreal: new method "transfer" that implements the transfer
  4885 principle of nonstandard analysis. With a subgoal that mentions
  4886 nonstandard types like "'a star", the command "apply transfer"
  4887 replaces it with an equivalent one that mentions only standard types.
  4888 To be successful, all free variables must have standard types; non-
  4889 standard variables must have explicit universal quantifiers.
  4890 
  4891 * Hyperreal: A theory of Taylor series.
  4892 
  4893 
  4894 *** HOLCF ***
  4895 
  4896 * Discontinued special version of 'constdefs' (which used to support
  4897 continuous functions) in favor of the general Pure one with full
  4898 type-inference.
  4899 
  4900 * New simplification procedure for solving continuity conditions; it
  4901 is much faster on terms with many nested lambda abstractions (cubic
  4902 instead of exponential time).
  4903 
  4904 * New syntax for domain package: selector names are now optional.
  4905 Parentheses should be omitted unless argument is lazy, for example:
  4906 
  4907   domain 'a stream = cons "'a" (lazy "'a stream")
  4908 
  4909 * New command 'fixrec' for defining recursive functions with pattern
  4910 matching; defining multiple functions with mutual recursion is also
  4911 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4912 sinr, or any data constructor defined by the domain package. The given
  4913 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4914 syntax and examples.
  4915 
  4916 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4917 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4918 but the proof obligation additionally includes an admissibility
  4919 requirement. The packages generate instances of class cpo or pcpo,
  4920 with continuity and strictness theorems for Rep and Abs.
  4921 
  4922 * HOLCF: Many theorems have been renamed according to a more standard naming
  4923 scheme (INCOMPATIBILITY):
  4924 
  4925   foo_inject:  "foo$x = foo$y ==> x = y"
  4926   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4927   foo_less:    "(foo$x << foo$y) = (x << y)"
  4928   foo_strict:  "foo$UU = UU"
  4929   foo_defined: "... ==> foo$x ~= UU"
  4930   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4931 
  4932 
  4933 *** ZF ***
  4934 
  4935 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4936 including the First Isomorphism Theorem (on quotienting by the kernel
  4937 of a homomorphism).
  4938 
  4939 * ZF/Simplifier: install second copy of type solver that actually
  4940 makes use of TC rules declared to Isar proof contexts (or locales);
  4941 the old version is still required for ML proof scripts.
  4942 
  4943 
  4944 *** Cube ***
  4945 
  4946 * Converted to Isar theory format; use locales instead of axiomatic
  4947 theories.
  4948 
  4949 
  4950 *** ML ***
  4951 
  4952 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  4953 for ||>, ||>>, |>>,
  4954 
  4955 * Pure/library.ML no longer defines its own option datatype, but uses
  4956 that of the SML basis, which has constructors NONE and SOME instead of
  4957 None and Some, as well as exception Option.Option instead of OPTION.
  4958 The functions the, if_none, is_some, is_none have been adapted
  4959 accordingly, while Option.map replaces apsome.
  4960 
  4961 * Pure/library.ML: the exception LIST has been given up in favour of
  4962 the standard exceptions Empty and Subscript, as well as
  4963 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  4964 superceded by the standard hd and tl functions etc.
  4965 
  4966 A number of basic list functions are no longer exported to the ML
  4967 toplevel, as they are variants of predefined functions.  The following
  4968 suggests how one can translate existing code:
  4969 
  4970     rev_append xs ys = List.revAppend (xs, ys)
  4971     nth_elem (i, xs) = List.nth (xs, i)
  4972     last_elem xs = List.last xs
  4973     flat xss = List.concat xss
  4974     seq fs = List.app fs
  4975     partition P xs = List.partition P xs
  4976     mapfilter f xs = List.mapPartial f xs
  4977 
  4978 * Pure/library.ML: several combinators for linear functional
  4979 transformations, notably reverse application and composition:
  4980 
  4981   x |> f                f #> g
  4982   (x, y) |-> f          f #-> g
  4983 
  4984 * Pure/library.ML: introduced/changed precedence of infix operators:
  4985 
  4986   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  4987   infix 2 ?;
  4988   infix 3 o oo ooo oooo;
  4989   infix 4 ~~ upto downto;
  4990 
  4991 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4992 infix operators.
  4993 
  4994 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4995 fold_map support linear functional transformations and nesting.  For
  4996 example:
  4997 
  4998   fold f [x1, ..., xN] y =
  4999     y |> f x1 |> ... |> f xN
  5000 
  5001   (fold o fold) f [xs1, ..., xsN] y =
  5002     y |> fold f xs1 |> ... |> fold f xsN
  5003 
  5004   fold f [x1, ..., xN] =
  5005     f x1 #> ... #> f xN
  5006 
  5007   (fold o fold) f [xs1, ..., xsN] =
  5008     fold f xs1 #> ... #> fold f xsN
  5009 
  5010 * Pure/library.ML: the following selectors on type 'a option are
  5011 available:
  5012 
  5013   the:               'a option -> 'a  (*partial*)
  5014   these:             'a option -> 'a  where 'a = 'b list
  5015   the_default: 'a -> 'a option -> 'a
  5016   the_list:          'a option -> 'a list
  5017 
  5018 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5019 basic operations for association lists, following natural argument
  5020 order; moreover the explicit equality predicate passed here avoids
  5021 potentially expensive polymorphic runtime equality checks.
  5022 The old functions may be expressed as follows:
  5023 
  5024   assoc = uncurry (AList.lookup (op =))
  5025   assocs = these oo AList.lookup (op =)
  5026   overwrite = uncurry (AList.update (op =)) o swap
  5027 
  5028 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5029 
  5030   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5031   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5032 
  5033 replacing make_keylist and keyfilter (occassionally used)
  5034 Naive rewrites:
  5035 
  5036   make_keylist = AList.make
  5037   keyfilter = AList.find (op =)
  5038 
  5039 * eq_fst and eq_snd now take explicit equality parameter, thus
  5040   avoiding eqtypes. Naive rewrites:
  5041 
  5042     eq_fst = eq_fst (op =)
  5043     eq_snd = eq_snd (op =)
  5044 
  5045 * Removed deprecated apl and apr (rarely used).
  5046   Naive rewrites:
  5047 
  5048     apl (n, op) =>>= curry op n
  5049     apr (op, m) =>>= fn n => op (n, m)
  5050 
  5051 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5052 provides a reasonably efficient light-weight implementation of sets as
  5053 lists.
  5054 
  5055 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5056 few new operations; existing lookup and update are now curried to
  5057 follow natural argument order (for use with fold etc.);
  5058 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5059 
  5060 * Pure/General: output via the Isabelle channels of
  5061 writeln/warning/error etc. is now passed through Output.output, with a
  5062 hook for arbitrary transformations depending on the print_mode
  5063 (cf. Output.add_mode -- the first active mode that provides a output
  5064 function wins).  Already formatted output may be embedded into further
  5065 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5066 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5067 accommodate easy composition of diagnostic messages etc.  Programmers
  5068 rarely need to care about Output.output or Output.raw at all, with
  5069 some notable exceptions: Output.output is required when bypassing the
  5070 standard channels (writeln etc.), or in token translations to produce
  5071 properly formatted results; Output.raw is required when capturing
  5072 already output material that will eventually be presented to the user
  5073 a second time.  For the default print mode, both Output.output and
  5074 Output.raw have no effect.
  5075 
  5076 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5077 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5078 cumulative results are displayed at the end of a batch session.
  5079 
  5080 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5081 replaced by File.platform_path and File.shell_path (with appropriate
  5082 hooks).  This provides a clean interface for unusual systems where the
  5083 internal and external process view of file names are different.
  5084 
  5085 * Pure: more efficient orders for basic syntactic entities: added
  5086 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5087 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5088 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5089 orders now -- potential INCOMPATIBILITY for code that depends on a
  5090 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5091 Library.sort_strings on result).
  5092 
  5093 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5094 fold_types traverse types/terms from left to right, observing natural
  5095 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5096 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5097 
  5098 * Pure: name spaces have been refined, with significant changes of the
  5099 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5100 to extern(_table).  The plain name entry path is superceded by a
  5101 general 'naming' context, which also includes the 'policy' to produce
  5102 a fully qualified name and external accesses of a fully qualified
  5103 name; NameSpace.extend is superceded by context dependent
  5104 Sign.declare_name.  Several theory and proof context operations modify
  5105 the naming context.  Especially note Theory.restore_naming and
  5106 ProofContext.restore_naming to get back to a sane state; note that
  5107 Theory.add_path is no longer sufficient to recover from
  5108 Theory.absolute_path in particular.
  5109 
  5110 * Pure: new flags short_names (default false) and unique_names
  5111 (default true) for controlling output of qualified names.  If
  5112 short_names is set, names are printed unqualified.  If unique_names is
  5113 reset, the name prefix is reduced to the minimum required to achieve
  5114 the original result when interning again, even if there is an overlap
  5115 with earlier declarations.
  5116 
  5117 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5118 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5119 (useful for printing error messages).  INCOMPATIBILITY.
  5120 
  5121 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5122 Theory.theory are now identified, referring to the universal
  5123 Context.theory (see Pure/context.ML).  Actual signature and theory
  5124 content is managed as theory data.  The old code and interfaces were
  5125 spread over many files and structures; the new arrangement introduces
  5126 considerable INCOMPATIBILITY to gain more clarity:
  5127 
  5128   Context -- theory management operations (name, identity, inclusion,
  5129     parents, ancestors, merge, etc.), plus generic theory data;
  5130 
  5131   Sign -- logical signature and syntax operations (declaring consts,
  5132     types, etc.), plus certify/read for common entities;
  5133 
  5134   Theory -- logical theory operations (stating axioms, definitions,
  5135     oracles), plus a copy of logical signature operations (consts,
  5136     types, etc.); also a few basic management operations (Theory.copy,
  5137     Theory.merge, etc.)
  5138 
  5139 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5140 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5141 for convenience -- they merely return the theory.
  5142 
  5143 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5144 
  5145 * Pure: the Isar proof context type is already defined early in Pure
  5146 as Context.proof (note that ProofContext.context and Proof.context are
  5147 aliases, where the latter is the preferred name).  This enables other
  5148 Isabelle components to refer to that type even before Isar is present.
  5149 
  5150 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5151 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5152 any of these kinds.  For example, Sign.intern typeK is now
  5153 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5154 Theory.hide_types.  Also note that former
  5155 Theory.hide_classes/types/consts are now
  5156 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5157 internalize their arguments!  INCOMPATIBILITY.
  5158 
  5159 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5160 datatype thmref (with constructors Name and NameSelection) instead of
  5161 plain string -- INCOMPATIBILITY;
  5162 
  5163 * Pure: cases produced by proof methods specify options, where NONE
  5164 means to remove case bindings -- INCOMPATIBILITY in
  5165 (RAW_)METHOD_CASES.
  5166 
  5167 * Pure: the following operations retrieve axioms or theorems from a
  5168 theory node or theory hierarchy, respectively:
  5169 
  5170   Theory.axioms_of: theory -> (string * term) list
  5171   Theory.all_axioms_of: theory -> (string * term) list
  5172   PureThy.thms_of: theory -> (string * thm) list
  5173   PureThy.all_thms_of: theory -> (string * thm) list
  5174 
  5175 * Pure: print_tac now outputs the goal through the trace channel.
  5176 
  5177 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5178 Reference Toplevel.debug (default false) controls detailed printing
  5179 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5180 controls execution profiling -- set to 1 for time and 2 for space
  5181 (both increase the runtime).
  5182 
  5183 * Isar session: The initial use of ROOT.ML is now always timed,
  5184 i.e. the log will show the actual process times, in contrast to the
  5185 elapsed wall-clock time that the outer shell wrapper produces.
  5186 
  5187 * Simplifier: improved handling of bound variables (nameless
  5188 representation, avoid allocating new strings).  Simprocs that invoke
  5189 the Simplifier recursively should use Simplifier.inherit_bounds to
  5190 avoid local name clashes.  Failure to do so produces warnings
  5191 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5192 for further details.
  5193 
  5194 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5195 bindings for all theorems stored within a given theory; this may help
  5196 in porting non-Isar theories to Isar ones, while keeping ML proof
  5197 scripts for the time being.
  5198 
  5199 * ML operator HTML.with_charset specifies the charset begin used for
  5200 generated HTML files.  For example:
  5201 
  5202   HTML.with_charset "utf-8" use_thy "Hebrew";
  5203   HTML.with_charset "utf-8" use_thy "Chinese";
  5204 
  5205 
  5206 *** System ***
  5207 
  5208 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5209 isabelle, isatool etc.).
  5210 
  5211 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5212 isatool doc, isatool mkdir, display_drafts etc.).
  5213 
  5214 * isatool usedir: option -f allows specification of the ML file to be
  5215 used by Isabelle; default is ROOT.ML.
  5216 
  5217 * New isatool version outputs the version identifier of the Isabelle
  5218 distribution being used.
  5219 
  5220 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5221 (containing Boolean satisfiability problems) into Isabelle/HOL
  5222 theories.
  5223 
  5224 
  5225 
  5226 New in Isabelle2004 (April 2004)
  5227 --------------------------------
  5228 
  5229 *** General ***
  5230 
  5231 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5232   Replaces linorder.ML.
  5233 
  5234 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5235   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5236   (\<a>...\<z>), are now considered normal letters, and can therefore
  5237   be used anywhere where an ASCII letter (a...zA...Z) has until
  5238   now. COMPATIBILITY: This obviously changes the parsing of some
  5239   terms, especially where a symbol has been used as a binder, say
  5240   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5241   as an identifier.  Fix it by inserting a space around former
  5242   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5243   existing theory and ML files.
  5244 
  5245 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5246 
  5247 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5248   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5249   a normal (but invisible) letter. For multiple letter subscripts repeat
  5250   \<^isub> like this: x\<^isub>1\<^isub>2.
  5251 
  5252 * Pure: There are now sub-/superscripts that can span more than one
  5253   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5254   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5255   superscript. The new control characters are not identifier parts.
  5256 
  5257 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5258   content of "..." to the latex file instead of \isacntrl... . The "..."
  5259   may consist of any printable characters excluding the end bracket >.
  5260 
  5261 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5262   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5263   declare constants "final", which prevents their being given a definition
  5264   later.  It is useful for constants whose behaviour is fixed axiomatically
  5265   rather than definitionally, such as the meta-logic connectives.
  5266 
  5267 * Pure: 'instance' now handles general arities with general sorts
  5268   (i.e. intersections of classes),
  5269 
  5270 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5271   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5272   It can be changed to alter the colors/layout of generated pages.
  5273 
  5274 
  5275 *** Isar ***
  5276 
  5277 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5278   cut_tac, subgoal_tac and thin_tac:
  5279   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5280     locales are no longer forced to write Isar proof scripts.
  5281     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5282     emulations.
  5283   - INCOMPATIBILITY: names of variables to be instantiated may no
  5284     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5285     This is consistent with the instantiation attribute "where".
  5286 
  5287 * Attributes "where" and "of":
  5288   - Now take type variables of instantiated theorem into account when reading
  5289     the instantiation string.  This fixes a bug that caused instantiated
  5290     theorems to have too special types in some circumstances.
  5291   - "where" permits explicit instantiations of type variables.
  5292 
  5293 * Calculation commands "moreover" and "also" no longer interfere with
  5294   current facts ("this"), admitting arbitrary combinations with "then"
  5295   and derived forms.
  5296 
  5297 * Locales:
  5298   - Goal statements involving the context element "includes" no longer
  5299     generate theorems with internal delta predicates (those ending on
  5300     "_axioms") in the premise.
  5301     Resolve particular premise with <locale>.intro to obtain old form.
  5302   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5303     specification and "includes" elements in goal statement.
  5304   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5305     [intro?] and [elim?] (respectively) by default.
  5306   - Experimental command for instantiation of locales in proof contexts:
  5307         instantiate <label>[<attrs>]: <loc>
  5308     Instantiates locale <loc> and adds all its theorems to the current context
  5309     taking into account their attributes.  Label and attrs are optional
  5310     modifiers, like in theorem declarations.  If present, names of
  5311     instantiated theorems are qualified with <label>, and the attributes
  5312     <attrs> are applied after any attributes these theorems might have already.
  5313       If the locale has assumptions, a chained fact of the form
  5314     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5315     are derived.  The command does not support old-style locales declared
  5316     with "locale (open)".
  5317       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5318 
  5319 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5320   (Isar) contexts.
  5321 
  5322 
  5323 *** HOL ***
  5324 
  5325 * Proof import: new image HOL4 contains the imported library from
  5326   the HOL4 system with about 2500 theorems. It is imported by
  5327   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5328   can be used like any other Isabelle image.  See
  5329   HOL/Import/HOL/README for more information.
  5330 
  5331 * Simplifier:
  5332   - Much improved handling of linear and partial orders.
  5333     Reasoners for linear and partial orders are set up for type classes
  5334     "linorder" and "order" respectively, and are added to the default simpset
  5335     as solvers.  This means that the simplifier can build transitivity chains
  5336     to solve goals from the assumptions.
  5337   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5338     of blast or auto after simplification become unnecessary because the goal
  5339     is solved by simplification already.
  5340 
  5341 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5342     all proved in axiomatic type classes for semirings, rings and fields.
  5343 
  5344 * Numerics:
  5345   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5346     now formalized using the Ring_and_Field theory mentioned above.
  5347   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5348     than before, because now they are set up once in a generic manner.
  5349   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5350     Look for the general versions in Ring_and_Field (and Power if they concern
  5351     exponentiation).
  5352 
  5353 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5354 
  5355 * Records:
  5356   - Record types are now by default printed with their type abbreviation
  5357     instead of the list of all field types. This can be configured via
  5358     the reference "print_record_type_abbr".
  5359   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5360     (not enabled by default).
  5361   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5362     EX x. x = sel r to True (not enabled by default).
  5363   - Tactic "record_split_simp_tac" to split and simplify records added.
  5364 
  5365 * 'specification' command added, allowing for definition by
  5366   specification.  There is also an 'ax_specification' command that
  5367   introduces the new constants axiomatically.
  5368 
  5369 * arith(_tac) is now able to generate counterexamples for reals as well.
  5370 
  5371 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5372 
  5373 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5374   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5375 
  5376 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5377   matrix theory to linear programming.
  5378 
  5379 * Unions and Intersections:
  5380   The latex output syntax of UN and INT has been changed
  5381   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5382   i.e. the index formulae has become a subscript.
  5383   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5384 
  5385 * Unions and Intersections over Intervals:
  5386   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5387   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5388   like in normal math, and corresponding versions for < and for intersection.
  5389 
  5390 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5391   lexicographic dictonary ordering has been added as "lexord".
  5392 
  5393 * ML: the legacy theory structures Int and List have been removed. They had
  5394   conflicted with ML Basis Library structures having the same names.
  5395 
  5396 * 'refute' command added to search for (finite) countermodels.  Only works
  5397   for a fragment of HOL.  The installation of an external SAT solver is
  5398   highly recommended.  See "HOL/Refute.thy" for details.
  5399 
  5400 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5401   formulae under an assignment of free variables to random values.
  5402   In contrast to 'refute', it can deal with inductive datatypes,
  5403   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5404   for examples.
  5405 
  5406 
  5407 *** HOLCF ***
  5408 
  5409 * Streams now come with concatenation and are part of the HOLCF image
  5410 
  5411 
  5412 
  5413 New in Isabelle2003 (May 2003)
  5414 ------------------------------
  5415 
  5416 *** General ***
  5417 
  5418 * Provers/simplifier:
  5419 
  5420   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5421     Assumptions are now subject to complete mutual simplification,
  5422     not just from left to right. The simplifier now preserves
  5423     the order of assumptions.
  5424 
  5425     Potential INCOMPATIBILITY:
  5426 
  5427     -- simp sometimes diverges where the old version did
  5428        not, e.g. invoking simp on the goal
  5429 
  5430         [| P (f x); y = x; f x = f y |] ==> Q
  5431 
  5432        now gives rise to the infinite reduction sequence
  5433 
  5434         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5435 
  5436        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5437        kind of problem.
  5438 
  5439     -- Tactics combining classical reasoner and simplification (such as auto)
  5440        are also affected by this change, because many of them rely on
  5441        simp. They may sometimes diverge as well or yield a different numbers
  5442        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5443        in case of problems. Sometimes subsequent calls to the classical
  5444        reasoner will fail because a preceeding call to the simplifier too
  5445        eagerly simplified the goal, e.g. deleted redundant premises.
  5446 
  5447   - The simplifier trace now shows the names of the applied rewrite rules
  5448 
  5449   - You can limit the number of recursive invocations of the simplifier
  5450     during conditional rewriting (where the simplifie tries to solve the
  5451     conditions before applying the rewrite rule):
  5452     ML "simp_depth_limit := n"
  5453     where n is an integer. Thus you can force termination where previously
  5454     the simplifier would diverge.
  5455 
  5456   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5457 
  5458   - No longer aborts on failed congruence proof.  Instead, the
  5459     congruence is ignored.
  5460 
  5461 * Pure: New generic framework for extracting programs from constructive
  5462   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5463   as HOL/Extraction for some case studies.
  5464 
  5465 * Pure: The main goal of the proof state is no longer shown by default, only
  5466 the subgoals. This behaviour is controlled by a new flag.
  5467    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5468 (ML: Proof.show_main_goal).
  5469 
  5470 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5471 rules whose conclusion matches subgoal 1:
  5472       PG menu: Isabelle/Isar -> Show me -> matching rules
  5473 The rules are ordered by how closely they match the subgoal.
  5474 In particular, rules that solve a subgoal outright are displayed first
  5475 (or rather last, the way they are printed).
  5476 (ML: ProofGeneral.print_intros())
  5477 
  5478 * Pure: New flag trace_unify_fail causes unification to print
  5479 diagnostic information (PG: in trace buffer) when it fails. This is
  5480 useful for figuring out why single step proofs like rule, erule or
  5481 assumption failed.
  5482 
  5483 * Pure: Locale specifications now produce predicate definitions
  5484 according to the body of text (covering assumptions modulo local
  5485 definitions); predicate "loc_axioms" covers newly introduced text,
  5486 while "loc" is cumulative wrt. all included locale expressions; the
  5487 latter view is presented only on export into the global theory
  5488 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5489 on the old view without predicates;
  5490 
  5491 * Pure: predefined locales "var" and "struct" are useful for sharing
  5492 parameters (as in CASL, for example); just specify something like
  5493 ``var x + var y + struct M'' as import;
  5494 
  5495 * Pure: improved thms_containing: proper indexing of facts instead of
  5496 raw theorems; check validity of results wrt. current name space;
  5497 include local facts of proof configuration (also covers active
  5498 locales), cover fixed variables in index; may use "_" in term
  5499 specification; an optional limit for the number of printed facts may
  5500 be given (the default is 40);
  5501 
  5502 * Pure: disallow duplicate fact bindings within new-style theory files
  5503 (batch-mode only);
  5504 
  5505 * Provers: improved induct method: assumptions introduced by case
  5506 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5507 the goal statement); "foo" still refers to all facts collectively;
  5508 
  5509 * Provers: the function blast.overloaded has been removed: all constants
  5510 are regarded as potentially overloaded, which improves robustness in exchange
  5511 for slight decrease in efficiency;
  5512 
  5513 * Provers/linorder: New generic prover for transitivity reasoning over
  5514 linear orders.  Note: this prover is not efficient!
  5515 
  5516 * Isar: preview of problems to finish 'show' now produce an error
  5517 rather than just a warning (in interactive mode);
  5518 
  5519 
  5520 *** HOL ***
  5521 
  5522 * arith(_tac)
  5523 
  5524  - Produces a counter example if it cannot prove a goal.
  5525    Note that the counter example may be spurious if the goal is not a formula
  5526    of quantifier-free linear arithmetic.
  5527    In ProofGeneral the counter example appears in the trace buffer.
  5528 
  5529  - Knows about div k and mod k where k is a numeral of type nat or int.
  5530 
  5531  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5532    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5533    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5534 
  5535 * simp's arithmetic capabilities have been enhanced a bit: it now
  5536 takes ~= in premises into account (by performing a case split);
  5537 
  5538 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5539 are distributed over a sum of terms;
  5540 
  5541 * New tactic "trans_tac" and method "trans" instantiate
  5542 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5543 "<=", "<" and "=").
  5544 
  5545 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5546 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5547 
  5548 * 'typedef' command has new option "open" to suppress the set
  5549 definition;
  5550 
  5551 * functions Min and Max on finite sets have been introduced (theory
  5552 Finite_Set);
  5553 
  5554 * attribute [symmetric] now works for relations as well; it turns
  5555 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5556 
  5557 * induct over a !!-quantified statement (say !!x1..xn):
  5558   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5559 
  5560 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5561 %x. None. Warning: empty_def now refers to the previously hidden definition
  5562 of the empty set.
  5563 
  5564 * Algebra: formalization of classical algebra.  Intended as base for
  5565 any algebraic development in Isabelle.  Currently covers group theory
  5566 (up to Sylow's theorem) and ring theory (Universal Property of
  5567 Univariate Polynomials).  Contributions welcome;
  5568 
  5569 * GroupTheory: deleted, since its material has been moved to Algebra;
  5570 
  5571 * Complex: new directory of the complex numbers with numeric constants,
  5572 nonstandard complex numbers, and some complex analysis, standard and
  5573 nonstandard (Jacques Fleuriot);
  5574 
  5575 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5576 
  5577 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5578 Fleuriot);
  5579 
  5580 * Real/HahnBanach: updated and adapted to locales;
  5581 
  5582 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5583 Gray and Kramer);
  5584 
  5585 * UNITY: added the Meier-Sanders theory of progress sets;
  5586 
  5587 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5588 as abstract algorithms, instantiated to the JVM;
  5589 
  5590 * Bali: Java source language formalization. Type system, operational
  5591 semantics, axiomatic semantics. Supported language features:
  5592 classes, interfaces, objects,virtual methods, static methods,
  5593 static/instance fields, arrays, access modifiers, definite
  5594 assignment, exceptions.
  5595 
  5596 
  5597 *** ZF ***
  5598 
  5599 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5600 universe, etc.);
  5601 
  5602 * Main ZF: virtually all theories converted to new-style format;
  5603 
  5604 
  5605 *** ML ***
  5606 
  5607 * Pure: Tactic.prove provides sane interface for internal proofs;
  5608 omits the infamous "standard" operation, so this is more appropriate
  5609 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5610 
  5611 * Pure: improved error reporting of simprocs;
  5612 
  5613 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5614 up simprocs;
  5615 
  5616 
  5617 *** Document preparation ***
  5618 
  5619 * uses \par instead of \\ for line breaks in theory text. This may
  5620 shift some page breaks in large documents. To get the old behaviour
  5621 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5622 
  5623 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5624 other packages
  5625 
  5626 * \<euro> now needs package babel/greek instead of marvosym (which
  5627 broke \Rightarrow)
  5628 
  5629 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5630 textcomp package)
  5631 
  5632 
  5633 
  5634 New in Isabelle2002 (March 2002)
  5635 --------------------------------
  5636 
  5637 *** Document preparation ***
  5638 
  5639 * greatly simplified document preparation setup, including more
  5640 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5641 instructive isatool mkdir; users should basically be able to get
  5642 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5643 users may run a separate document processing stage manually like this:
  5644 "isatool usedir -D output HOL Test && isatool document Test/output";
  5645 
  5646 * theory dependency graph may now be incorporated into documents;
  5647 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5648 with \includegraphics of LaTeX;
  5649 
  5650 * proper spacing of consecutive markup elements, especially text
  5651 blocks after section headings;
  5652 
  5653 * support bold style (for single symbols only), input syntax is like
  5654 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5655 
  5656 * \<bullet> is now output as bold \cdot by default, which looks much
  5657 better in printed text;
  5658 
  5659 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5660 note that these symbols are currently unavailable in Proof General /
  5661 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5662 
  5663 * isatool latex no longer depends on changed TEXINPUTS, instead
  5664 isatool document copies the Isabelle style files to the target
  5665 location;
  5666 
  5667 
  5668 *** Isar ***
  5669 
  5670 * Pure/Provers: improved proof by cases and induction;
  5671   - 'case' command admits impromptu naming of parameters (such as
  5672     "case (Suc n)");
  5673   - 'induct' method divinates rule instantiation from the inductive
  5674     claim; no longer requires excessive ?P bindings for proper
  5675     instantiation of cases;
  5676   - 'induct' method properly enumerates all possibilities of set/type
  5677     rules; as a consequence facts may be also passed through *type*
  5678     rules without further ado;
  5679   - 'induct' method now derives symbolic cases from the *rulified*
  5680     rule (before it used to rulify cases stemming from the internal
  5681     atomized version); this means that the context of a non-atomic
  5682     statement becomes is included in the hypothesis, avoiding the
  5683     slightly cumbersome show "PROP ?case" form;
  5684   - 'induct' may now use elim-style induction rules without chaining
  5685     facts, using ``missing'' premises from the goal state; this allows
  5686     rules stemming from inductive sets to be applied in unstructured
  5687     scripts, while still benefitting from proper handling of non-atomic
  5688     statements; NB: major inductive premises need to be put first, all
  5689     the rest of the goal is passed through the induction;
  5690   - 'induct' proper support for mutual induction involving non-atomic
  5691     rule statements (uses the new concept of simultaneous goals, see
  5692     below);
  5693   - append all possible rule selections, but only use the first
  5694     success (no backtracking);
  5695   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5696   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5697   - added 'print_induct_rules' (covered by help item in recent Proof
  5698     General versions);
  5699   - moved induct/cases attributes to Pure, methods to Provers;
  5700   - generic method setup instantiated for FOL and HOL;
  5701 
  5702 * Pure: support multiple simultaneous goal statements, for example
  5703 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5704 meta-level mechanism, this acts as if several individual goals had
  5705 been stated separately; in particular common proof methods need to be
  5706 repeated in order to cover all claims; note that a single elimination
  5707 step is *not* sufficient to establish the two conjunctions, so this
  5708 fails:
  5709 
  5710   assume "A & B" then have A and B ..   (*".." fails*)
  5711 
  5712 better use "obtain" in situations as above; alternative refer to
  5713 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5714 
  5715 * Pure: proper integration with ``locales''; unlike the original
  5716 version by Florian Kammller, Isar locales package high-level proof
  5717 contexts rather than raw logical ones (e.g. we admit to include
  5718 attributes everywhere); operations on locales include merge and
  5719 rename; support for implicit arguments (``structures''); simultaneous
  5720 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5721 some examples;
  5722 
  5723 * Pure: the following commands have been ``localized'', supporting a
  5724 target locale specification "(in name)": 'lemma', 'theorem',
  5725 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5726 stored both within the locale and at the theory level (exported and
  5727 qualified by the locale name);
  5728 
  5729 * Pure: theory goals may now be specified in ``long'' form, with
  5730 ad-hoc contexts consisting of arbitrary locale elements. for example
  5731 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5732 definitions may be given, too); the result is a meta-level rule with
  5733 the context elements being discharged in the obvious way;
  5734 
  5735 * Pure: new proof command 'using' allows to augment currently used
  5736 facts after a goal statement ('using' is syntactically analogous to
  5737 'apply', but acts on the goal's facts only); this allows chained facts
  5738 to be separated into parts given before and after a claim, as in
  5739 ``from a and b have C using d and e <proof>'';
  5740 
  5741 * Pure: renamed "antecedent" case to "rule_context";
  5742 
  5743 * Pure: new 'judgment' command records explicit information about the
  5744 object-logic embedding (used by several tools internally); no longer
  5745 use hard-wired "Trueprop";
  5746 
  5747 * Pure: added 'corollary' command;
  5748 
  5749 * Pure: fixed 'token_translation' command;
  5750 
  5751 * Pure: removed obsolete 'exported' attribute;
  5752 
  5753 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5754 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5755 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5756 
  5757 * Pure: method 'atomize' presents local goal premises as object-level
  5758 statements (atomic meta-level propositions); setup controlled via
  5759 rewrite rules declarations of 'atomize' attribute; example
  5760 application: 'induct' method with proper rule statements in improper
  5761 proof *scripts*;
  5762 
  5763 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5764 now consider the syntactic context of assumptions, giving a better
  5765 chance to get type-inference of the arguments right (this is
  5766 especially important for locales);
  5767 
  5768 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5769 mode;
  5770 
  5771 * Pure/obtain: the formal conclusion "thesis", being marked as
  5772 ``internal'', may no longer be reference directly in the text;
  5773 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5774 situations;
  5775 
  5776 * Pure: generic 'sym' attribute which declares a rule both as pure
  5777 'elim?' and for the 'symmetric' operation;
  5778 
  5779 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5780 text; the fixed correlation with particular command syntax has been
  5781 discontinued;
  5782 
  5783 * Pure: new method 'rules' is particularly well-suited for proof
  5784 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5785 but often produces more compact proof terms with less detours;
  5786 
  5787 * Pure/Provers/classical: simplified integration with pure rule
  5788 attributes and methods; the classical "intro?/elim?/dest?"
  5789 declarations coincide with the pure ones; the "rule" method no longer
  5790 includes classically swapped intros; "intro" and "elim" methods no
  5791 longer pick rules from the context; also got rid of ML declarations
  5792 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5793 INCOMPATIBILITY;
  5794 
  5795 * Provers/classical: attribute 'swapped' produces classical inversions
  5796 of introduction rules;
  5797 
  5798 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5799 rules instead of full simplifier context; 'iff' attribute handles
  5800 conditional rules;
  5801 
  5802 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5803 
  5804 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5805 "(permissive)" option to recover old behavior;
  5806 
  5807 * HOL: 'inductive' no longer features separate (collective) attributes
  5808 for 'intros' (was found too confusing);
  5809 
  5810 * HOL: properly declared induction rules less_induct and
  5811 wf_induct_rule;
  5812 
  5813 
  5814 *** HOL ***
  5815 
  5816 * HOL: moved over to sane numeral syntax; the new policy is as
  5817 follows:
  5818 
  5819   - 0 and 1 are polymorphic constants, which are defined on any
  5820   numeric type (nat, int, real etc.);
  5821 
  5822   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5823   binary representation internally;
  5824 
  5825   - type nat has special constructor Suc, and generally prefers Suc 0
  5826   over 1::nat and Suc (Suc 0) over 2::nat;
  5827 
  5828 This change may cause significant problems of INCOMPATIBILITY; here
  5829 are some hints on converting existing sources:
  5830 
  5831   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5832   entities, so expressions involving "-" (unary or binary minus) need
  5833   to be spaced properly;
  5834 
  5835   - existing occurrences of "1" may need to be constraint "1::nat" or
  5836   even replaced by Suc 0; similar for old "2";
  5837 
  5838   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5839 
  5840   - remove all special provisions on numerals in proofs;
  5841 
  5842 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5843 representation (depends on bin_arith_simps in the default context);
  5844 
  5845 * HOL: symbolic syntax for x^2 (numeral 2);
  5846 
  5847 * HOL: the class of all HOL types is now called "type" rather than
  5848 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5849 in axclass/classes, instance/arities, and (usually rare) occurrences
  5850 in typings (of consts etc.); internally the class is called
  5851 "HOL.type", ML programs should refer to HOLogic.typeS;
  5852 
  5853 * HOL/record package improvements:
  5854   - new derived operations "fields" to build a partial record section,
  5855     "extend" to promote a fixed record to a record scheme, and
  5856     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5857     declared as simp by default;
  5858   - shared operations ("more", "fields", etc.) now need to be always
  5859     qualified) --- potential INCOMPATIBILITY;
  5860   - removed "make_scheme" operations (use "make" with "extend") --
  5861     INCOMPATIBILITY;
  5862   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5863   - provides cases/induct rules for use with corresponding Isar
  5864     methods (for concrete records, record schemes, concrete more
  5865     parts, and schematic more parts -- in that order);
  5866   - internal definitions directly based on a light-weight abstract
  5867     theory of product types over typedef rather than datatype;
  5868 
  5869 * HOL: generic code generator for generating executable ML code from
  5870 specifications; specific support for HOL constructs such as inductive
  5871 datatypes and sets, as well as recursive functions; can be invoked
  5872 via 'generate_code' theory section;
  5873 
  5874 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5875 
  5876 * HOL: consolidated and renamed several theories.  In particular:
  5877         Ord.thy has been absorbed into HOL.thy
  5878         String.thy has been absorbed into List.thy
  5879 
  5880 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5881 (beware of argument permutation!);
  5882 
  5883 * HOL: linorder_less_split superseded by linorder_cases;
  5884 
  5885 * HOL/List: "nodups" renamed to "distinct";
  5886 
  5887 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5888 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5889   - Ex_def has changed, now need to use some_eq_ex
  5890 
  5891 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5892 in this (rare) case use:
  5893 
  5894   delSWrapper "split_all_tac"
  5895   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5896 
  5897 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5898 MAY FAIL;
  5899 
  5900 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5901 Isabelle's type classes, ^ on functions and relations has too general
  5902 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5903 necessary to attach explicit type constraints;
  5904 
  5905 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5906 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5907 renamed accordingly (eg "compI" -> "rel_compI").
  5908 
  5909 * HOL: syntax translations now work properly with numerals and records
  5910 expressions;
  5911 
  5912 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5913 of "lam" -- INCOMPATIBILITY;
  5914 
  5915 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5916 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5917 renamed "Product_Type.unit";
  5918 
  5919 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5920 
  5921 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5922 the "cases" method);
  5923 
  5924 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5925 Florian Kammller);
  5926 
  5927 * HOL/IMP: updated and converted to new-style theory format; several
  5928 parts turned into readable document, with proper Isar proof texts and
  5929 some explanations (by Gerwin Klein);
  5930 
  5931 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5932 
  5933 * HOL-Hyperreal is now a logic image;
  5934 
  5935 
  5936 *** HOLCF ***
  5937 
  5938 * Isar: consts/constdefs supports mixfix syntax for continuous
  5939 operations;
  5940 
  5941 * Isar: domain package adapted to new-style theory format, e.g. see
  5942 HOLCF/ex/Dnat.thy;
  5943 
  5944 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5945 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5946 lift.induct_tac, always use UU instead of Undef;
  5947 
  5948 * HOLCF/IMP: updated and converted to new-style theory;
  5949 
  5950 
  5951 *** ZF ***
  5952 
  5953 * Isar: proper integration of logic-specific tools and packages,
  5954 including theory commands '(co)inductive', '(co)datatype',
  5955 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  5956 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  5957 
  5958 * theory Main no longer includes AC; for the Axiom of Choice, base
  5959 your theory on Main_ZFC;
  5960 
  5961 * the integer library now covers quotients and remainders, with many
  5962 laws relating division to addition, multiplication, etc.;
  5963 
  5964 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  5965 typeless version of the formalism;
  5966 
  5967 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  5968 format;
  5969 
  5970 * ZF/Induct: new directory for examples of inductive definitions,
  5971 including theory Multiset for multiset orderings; converted to
  5972 new-style theory format;
  5973 
  5974 * ZF: many new theorems about lists, ordinals, etc.;
  5975 
  5976 
  5977 *** General ***
  5978 
  5979 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  5980 variable proof controls level of detail: 0 = no proofs (only oracle
  5981 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  5982 also ref manual for further ML interfaces;
  5983 
  5984 * Pure/axclass: removed obsolete ML interface
  5985 goal_subclass/goal_arity;
  5986 
  5987 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  5988 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5989 separate tokens, so expressions involving minus need to be spaced
  5990 properly;
  5991 
  5992 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5993 rather than "infixl" or "infixr";
  5994 
  5995 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5996 sort constraint specifications in type inference; e.g. "x::_::foo"
  5997 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5998 type variable);
  5999 
  6000 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  6001 control output of nested => (types); the default behavior is
  6002 "type_brackets";
  6003 
  6004 * Pure/syntax: builtin parse translation for "_constify" turns valued
  6005 tokens into AST constants;
  6006 
  6007 * Pure/syntax: prefer later declarations of translations and print
  6008 translation functions; potential INCOMPATIBILITY: need to reverse
  6009 multiple declarations for same syntax element constant;
  6010 
  6011 * Pure/show_hyps reset by default (in accordance to existing Isar
  6012 practice);
  6013 
  6014 * Provers/classical: renamed addaltern to addafter, addSaltern to
  6015 addSafter;
  6016 
  6017 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  6018 as well;
  6019 
  6020 * system: tested support for MacOS X; should be able to get Isabelle +
  6021 Proof General to work in a plain Terminal after installing Poly/ML
  6022 (e.g. from the Isabelle distribution area) and GNU bash alone
  6023 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  6024 support requires further installations, e.g. from
  6025 http://fink.sourceforge.net/);
  6026 
  6027 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  6028 
  6029 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  6030 of 40 MB), cf. ML_OPTIONS;
  6031 
  6032 * system: Proof General keywords specification is now part of the
  6033 Isabelle distribution (see etc/isar-keywords.el);
  6034 
  6035 * system: support for persistent Proof General sessions (refrain from
  6036 outdating all loaded theories on startup); user may create writable
  6037 logic images like this: ``isabelle -q HOL Test'';
  6038 
  6039 * system: smart selection of Isabelle process versus Isabelle
  6040 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  6041 run both "isabelle" and "Isabelle" even if file names are badly
  6042 damaged (executable inspects the case of the first letter of its own
  6043 name); added separate "isabelle-process" and "isabelle-interface";
  6044 
  6045 * system: refrain from any attempt at filtering input streams; no
  6046 longer support ``8bit'' encoding of old isabelle font, instead proper
  6047 iso-latin characters may now be used; the related isatools
  6048 "symbolinput" and "nonascii" have disappeared as well;
  6049 
  6050 * system: removed old "xterm" interface (the print modes "xterm" and
  6051 "xterm_color" are still available for direct use in a suitable
  6052 terminal);
  6053 
  6054 
  6055 
  6056 New in Isabelle99-2 (February 2001)
  6057 -----------------------------------
  6058 
  6059 *** Overview of INCOMPATIBILITIES ***
  6060 
  6061 * HOL: please note that theories in the Library and elsewhere often use the
  6062 new-style (Isar) format; to refer to their theorems in an ML script you must
  6063 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  6064 
  6065 * HOL: inductive package no longer splits induction rule aggressively,
  6066 but only as far as specified by the introductions given; the old
  6067 format may be recovered via ML function complete_split_rule or attribute
  6068 'split_rule (complete)';
  6069 
  6070 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  6071 gfp_Tarski to gfp_unfold;
  6072 
  6073 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  6074 
  6075 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  6076 relation); infix "^^" has been renamed "``"; infix "``" has been
  6077 renamed "`"; "univalent" has been renamed "single_valued";
  6078 
  6079 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  6080 operation;
  6081 
  6082 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  6083 
  6084 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  6085 
  6086 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  6087 consequence, it is no longer monotonic wrt. the local goal context
  6088 (which is now passed through the inductive cases);
  6089 
  6090 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  6091 \<gg> to \<ggreater>;
  6092 
  6093 
  6094 *** Document preparation ***
  6095 
  6096 * \isabellestyle{NAME} selects version of Isabelle output (currently
  6097 available: are "it" for near math-mode best-style output, "sl" for
  6098 slanted text style, and "tt" for plain type-writer; if no
  6099 \isabellestyle command is given, output is according to slanted
  6100 type-writer);
  6101 
  6102 * support sub/super scripts (for single symbols only), input syntax is
  6103 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  6104 
  6105 * some more standard symbols; see Appendix A of the system manual for
  6106 the complete list of symbols defined in isabellesym.sty;
  6107 
  6108 * improved isabelle style files; more abstract symbol implementation
  6109 (should now use \isamath{...} and \isatext{...} in custom symbol
  6110 definitions);
  6111 
  6112 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  6113 state; Note that presentation of goal states does not conform to
  6114 actual human-readable proof documents.  Please do not include goal
  6115 states into document output unless you really know what you are doing!
  6116 
  6117 * proper indentation of antiquoted output with proportional LaTeX
  6118 fonts;
  6119 
  6120 * no_document ML operator temporarily disables LaTeX document
  6121 generation;
  6122 
  6123 * isatool unsymbolize tunes sources for plain ASCII communication;
  6124 
  6125 
  6126 *** Isar ***
  6127 
  6128 * Pure: Isar now suffers initial goal statements to contain unbound
  6129 schematic variables (this does not conform to actual readable proof
  6130 documents, due to unpredictable outcome and non-compositional proof
  6131 checking); users who know what they are doing may use schematic goals
  6132 for Prolog-style synthesis of proven results;
  6133 
  6134 * Pure: assumption method (an implicit finishing) now handles actual
  6135 rules as well;
  6136 
  6137 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  6138 initial goal, declare "that" only as Pure intro (only for single
  6139 steps); the "that" rule assumption may now be involved in implicit
  6140 finishing, thus ".." becomes a feasible for trivial obtains;
  6141 
  6142 * Pure: default proof step now includes 'intro_classes'; thus trivial
  6143 instance proofs may be performed by "..";
  6144 
  6145 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  6146 statements as well;
  6147 
  6148 * Pure: more robust selection of calculational rules;
  6149 
  6150 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  6151 rule (as well as the assumption rule);
  6152 
  6153 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  6154 lemmas, using the graph browser tool;
  6155 
  6156 * Pure: predict failure of "show" in interactive mode;
  6157 
  6158 * Pure: 'thms_containing' now takes actual terms as arguments;
  6159 
  6160 * HOL: improved method 'induct' --- now handles non-atomic goals
  6161 (potential INCOMPATIBILITY); tuned error handling;
  6162 
  6163 * HOL: cases and induct rules now provide explicit hints about the
  6164 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  6165 any remaining facts are inserted into the goal verbatim;
  6166 
  6167 * HOL: local contexts (aka cases) may now contain term bindings as
  6168 well; the 'cases' and 'induct' methods new provide a ?case binding for
  6169 the result to be shown in each case;
  6170 
  6171 * HOL: added 'recdef_tc' command;
  6172 
  6173 * isatool convert assists in eliminating legacy ML scripts;
  6174 
  6175 
  6176 *** HOL ***
  6177 
  6178 * HOL/Library: a collection of generic theories to be used together
  6179 with main HOL; the theory loader path already includes this directory
  6180 by default; the following existing theories have been moved here:
  6181 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  6182 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  6183 
  6184 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  6185 modelling and verification task performed in Isabelle/HOL +
  6186 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  6187 
  6188 * HOL/Algebra: special summation operator SUM no longer exists, it has
  6189 been replaced by setsum; infix 'assoc' now has priority 50 (like
  6190 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  6191 'domain', this makes the theory consistent with mathematical
  6192 literature;
  6193 
  6194 * HOL basics: added overloaded operations "inverse" and "divide"
  6195 (infix "/"), syntax for generic "abs" operation, generic summation
  6196 operator \<Sum>;
  6197 
  6198 * HOL/typedef: simplified package, provide more useful rules (see also
  6199 HOL/subset.thy);
  6200 
  6201 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  6202 now expressed as a proper nested rule (old-style tactic scripts may
  6203 require atomize_strip_tac to cope with non-atomic premises);
  6204 
  6205 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  6206 to "split_conv" (old name still available for compatibility);
  6207 
  6208 * HOL: improved concrete syntax for strings (e.g. allows translation
  6209 rules with string literals);
  6210 
  6211 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  6212  and Fleuriot's mechanization of analysis, including the transcendental
  6213  functions for the reals;
  6214 
  6215 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  6216 
  6217 
  6218 *** CTT ***
  6219 
  6220 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  6221 "lam" is displayed as TWO lambda-symbols
  6222 
  6223 * CTT: theory Main now available, containing everything (that is, Bool
  6224 and Arith);
  6225 
  6226 
  6227 *** General ***
  6228 
  6229 * Pure: the Simplifier has been implemented properly as a derived rule
  6230 outside of the actual kernel (at last!); the overall performance
  6231 penalty in practical applications is about 50%, while reliability of
  6232 the Isabelle inference kernel has been greatly improved;
  6233 
  6234 * print modes "brackets" and &