NEWS
author wenzelm
Tue, 13 Dec 2011 23:23:51 +0100
changeset 46712 43a5b86bc102
parent 46681 024947a0e492
child 46745 ab10ce781e34
permissions -rw-r--r--
'datatype' specifications allow explicit sort constraints;
tuned signatures;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Prover IDE (PIDE) improvements:
    10 
    11   - markup for bound variables
    12   - markup for types of term variables (e.g. displayed as tooltips)
    13 
    14 * Rule attributes in local theory declarations (e.g. locale or class)
    15 are now statically evaluated: the resulting theorem is stored instead
    16 of the original expression.  INCOMPATIBILITY in rare situations, where
    17 the historic accident of dynamic re-evaluation in interpretations
    18 etc. was exploited.
    19 
    20 * Commands 'lemmas' and 'theorems' allow local variables using 'for'
    21 declaration, and results are standardized before being stored.  Thus
    22 old-style "standard" after instantiation or composition of facts
    23 becomes obsolete.  Minor INCOMPATIBILITY, due to potential change of
    24 indices of schematic variables.
    25 
    26 * Renamed inner syntax categories "num" to "num_token" and "xnum" to
    27 "xnum_token", in accordance to existing "float_token".  Minor
    28 INCOMPATIBILITY.  Note that in practice "num_const" etc. are mainly
    29 used instead.
    30 
    31 
    32 *** Pure ***
    33 
    34 * Obsolete command 'types' has been discontinued.  Use 'type_synonym'
    35 instead.  INCOMPATIBILITY.
    36 
    37 * Ancient code generator for SML and its commands 'code_module',
    38 'code_library', 'consts_code', 'types_code' have been discontinued.
    39 Use commands of the generic code generator instead. INCOMPATIBILITY.
    40 
    41 * Redundant attribute 'code_inline' has been discontinued. Use
    42 'code_unfold' instead. INCOMPATIBILITY.
    43 
    44 * Sort constraints are now propagated in simultaneous statements, just
    45 like type constraints.  INCOMPATIBILITY in rare situations, where
    46 distinct sorts used to be assigned accidentally.  For example:
    47 
    48   lemma "P (x::'a::foo)" and "Q (y::'a::bar)"  -- "now illegal"
    49 
    50   lemma "P (x::'a)" and "Q (y::'a::bar)"
    51     -- "now uniform 'a::bar instead of default sort for first occurence (!)"
    52 
    53 
    54 *** HOL ***
    55 
    56 * 'datatype' specifications allow explicit sort constraints.
    57 
    58 * Theory HOL/Library/Diagonalize has been removed. INCOMPATIBILITY, use
    59 theory HOL/Library/Nat_Bijection instead.
    60 
    61 * Session HOL-Word: Discontinued many redundant theorems specific to type
    62 'a word. INCOMPATIBILITY, use the corresponding generic theorems instead.
    63 
    64   word_sub_alt ~> word_sub_wi
    65   word_add_alt ~> word_add_def
    66   word_mult_alt ~> word_mult_def
    67   word_minus_alt ~> word_minus_def
    68   word_0_alt ~> word_0_wi
    69   word_1_alt ~> word_1_wi
    70   word_add_0 ~> add_0_left
    71   word_add_0_right ~> add_0_right
    72   word_mult_1 ~> mult_1_left
    73   word_mult_1_right ~> mult_1_right
    74   word_add_commute ~> add_commute
    75   word_add_assoc ~> add_assoc
    76   word_add_left_commute ~> add_left_commute
    77   word_mult_commute ~> mult_commute
    78   word_mult_assoc ~> mult_assoc
    79   word_mult_left_commute ~> mult_left_commute
    80   word_left_distrib ~> left_distrib
    81   word_right_distrib ~> right_distrib
    82   word_left_minus ~> left_minus
    83   word_diff_0_right ~> diff_0_right
    84   word_diff_self ~> diff_self
    85   word_diff_minus ~> diff_minus
    86   word_add_ac ~> add_ac
    87   word_mult_ac ~> mult_ac
    88   word_plus_ac0 ~> add_0_left add_0_right add_ac
    89   word_times_ac1 ~> mult_1_left mult_1_right mult_ac
    90   word_order_trans ~> order_trans
    91   word_order_refl ~> order_refl
    92   word_order_antisym ~> order_antisym
    93   word_order_linear ~> linorder_linear
    94   lenw1_zero_neq_one ~> zero_neq_one
    95   word_number_of_eq ~> number_of_eq
    96 
    97 * Clarified attribute "mono_set": pure declararation without modifying
    98 the result of the fact expression.
    99 
   100 * "Transitive_Closure.ntrancl": bounded transitive closure on
   101 relations.
   102 
   103 * Constant "Set.not_member" now qualifed.  INCOMPATIBILITY.
   104 
   105 * "sublists" moved to theory More_List.  INCOMPATIBILITY.
   106 
   107 * Theory Int: Discontinued many legacy theorems specific to type int.
   108 INCOMPATIBILITY, use the corresponding generic theorems instead.
   109 
   110   zminus_zminus ~> minus_minus
   111   zminus_0 ~> minus_zero
   112   zminus_zadd_distrib ~> minus_add_distrib
   113   zadd_commute ~> add_commute
   114   zadd_assoc ~> add_assoc
   115   zadd_left_commute ~> add_left_commute
   116   zadd_ac ~> add_ac
   117   zmult_ac ~> mult_ac
   118   zadd_0 ~> add_0_left
   119   zadd_0_right ~> add_0_right
   120   zadd_zminus_inverse2 ~> left_minus
   121   zmult_zminus ~> mult_minus_left
   122   zmult_commute ~> mult_commute
   123   zmult_assoc ~> mult_assoc
   124   zadd_zmult_distrib ~> left_distrib
   125   zadd_zmult_distrib2 ~> right_distrib
   126   zdiff_zmult_distrib ~> left_diff_distrib
   127   zdiff_zmult_distrib2 ~> right_diff_distrib
   128   zmult_1 ~> mult_1_left
   129   zmult_1_right ~> mult_1_right
   130   zle_refl ~> order_refl
   131   zle_trans ~> order_trans
   132   zle_antisym ~> order_antisym
   133   zle_linear ~> linorder_linear
   134   zless_linear ~> linorder_less_linear
   135   zadd_left_mono ~> add_left_mono
   136   zadd_strict_right_mono ~> add_strict_right_mono
   137   zadd_zless_mono ~> add_less_le_mono
   138   int_0_less_1 ~> zero_less_one
   139   int_0_neq_1 ~> zero_neq_one
   140   zless_le ~> less_le
   141   zpower_zadd_distrib ~> power_add
   142   zero_less_zpower_abs_iff ~> zero_less_power_abs_iff
   143   zero_le_zpower_abs ~> zero_le_power_abs
   144 
   145 * Theory Deriv: Renamed
   146 
   147   DERIV_nonneg_imp_nonincreasing ~> DERIV_nonneg_imp_nondecreasing
   148 
   149 * New "case_product" attribute to generate a case rule doing multiple
   150 case distinctions at the same time.  E.g.
   151 
   152   list.exhaust [case_product nat.exhaust]
   153 
   154 produces a rule which can be used to perform case distinction on both
   155 a list and a nat.
   156 
   157 * Quickcheck:
   158   - Quickcheck returns variable assignments as counterexamples, which
   159     allows to reveal the underspecification of functions under test.
   160     For example, refuting "hd xs = x", it presents the variable
   161     assignment xs = [] and x = a1 as a counterexample, assuming that
   162     any property is false whenever "hd []" occurs in it.
   163     These counterexample are marked as potentially spurious, as
   164     Quickcheck also returns "xs = []" as a counterexample to the
   165     obvious theorem "hd xs = hd xs".
   166     After finding a potentially spurious counterexample, Quickcheck
   167     continues searching for genuine ones.
   168     By default, Quickcheck shows potentially spurious and genuine
   169     counterexamples. The option "genuine_only" sets quickcheck to
   170     only show genuine counterexamples.
   171  
   172 * Nitpick:
   173   - Fixed infinite loop caused by the 'peephole_optim' option and
   174     affecting 'rat' and 'real'.
   175 
   176 * Sledgehammer:
   177   - Added "lam_trans" and "minimize" options.
   178   - Renamed "slicing" ("no_slicing") option to "slice" ("dont_slice").
   179 
   180 * Metis:
   181   - Added possibility to specify lambda translations scheme as a
   182     parenthesized argument (e.g., "by (metis (lam_lifting) ...)").
   183 
   184 
   185 *** FOL ***
   186 
   187 * New "case_product" attribute (see HOL).
   188 
   189 
   190 *** ML ***
   191 
   192 * Antiquotation @{attributes [...]} embeds attribute source
   193 representation into the ML text, which is particularly useful with
   194 declarations like Local_Theory.note.
   195 
   196 * Structure Proof_Context follows standard naming scheme.  Old
   197 ProofContext has been discontinued.  INCOMPATIBILITY.
   198 
   199 * Refined Local_Theory.declaration {syntax, pervasive}, with subtle
   200 change of semantics: update is applied to auxiliary local theory
   201 context as well.
   202 
   203 * Modernized some old-style infix operations:
   204 
   205   addeqcongs    ~> Simplifier.add_eqcong
   206   deleqcongs    ~> Simplifier.del_eqcong
   207   addcongs      ~> Simplifier.add_cong
   208   delcongs      ~> Simplifier.del_cong
   209   setmksimps    ~> Simplifier.set_mksimps
   210   setmkcong     ~> Simplifier.set_mkcong
   211   setmksym      ~> Simplifier.set_mksym
   212   setmkeqTrue   ~> Simplifier.set_mkeqTrue
   213   settermless   ~> Simplifier.set_termless
   214   setsubgoaler  ~> Simplifier.set_subgoaler
   215   addsplits     ~> Splitter.add_split
   216   delsplits     ~> Splitter.del_split
   217 
   218 
   219 
   220 New in Isabelle2011-1 (October 2011)
   221 ------------------------------------
   222 
   223 *** General ***
   224 
   225 * Improved Isabelle/jEdit Prover IDE (PIDE), which can be invoked as
   226 "isabelle jedit" or "ISABELLE_HOME/Isabelle" on the command line.
   227 
   228   - Management of multiple theory files directly from the editor
   229     buffer store -- bypassing the file-system (no requirement to save
   230     files for checking).
   231 
   232   - Markup of formal entities within the text buffer, with semantic
   233     highlighting, tooltips and hyperlinks to jump to defining source
   234     positions.
   235 
   236   - Improved text rendering, with sub/superscripts in the source
   237     buffer (including support for copy/paste wrt. output panel, HTML
   238     theory output and other non-Isabelle text boxes).
   239 
   240   - Refined scheduling of proof checking and printing of results,
   241     based on interactive editor view.  (Note: jEdit folding and
   242     narrowing allows to restrict buffer perspectives explicitly.)
   243 
   244   - Reduced CPU performance requirements, usable on machines with few
   245     cores.
   246 
   247   - Reduced memory requirements due to pruning of unused document
   248     versions (garbage collection).
   249 
   250 See also ~~/src/Tools/jEdit/README.html for further information,
   251 including some remaining limitations.
   252 
   253 * Theory loader: source files are exclusively located via the master
   254 directory of each theory node (where the .thy file itself resides).
   255 The global load path (such as src/HOL/Library) has been discontinued.
   256 Note that the path element ~~ may be used to reference theories in the
   257 Isabelle home folder -- for instance, "~~/src/HOL/Library/FuncSet".
   258 INCOMPATIBILITY.
   259 
   260 * Theory loader: source files are identified by content via SHA1
   261 digests.  Discontinued former path/modtime identification and optional
   262 ISABELLE_FILE_IDENT plugin scripts.
   263 
   264 * Parallelization of nested Isar proofs is subject to
   265 Goal.parallel_proofs_threshold (default 100).  See also isabelle
   266 usedir option -Q.
   267 
   268 * Name space: former unsynchronized references are now proper
   269 configuration options, with more conventional names:
   270 
   271   long_names   ~> names_long
   272   short_names  ~> names_short
   273   unique_names ~> names_unique
   274 
   275 Minor INCOMPATIBILITY, need to declare options in context like this:
   276 
   277   declare [[names_unique = false]]
   278 
   279 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
   280 that the result needs to be unique, which means fact specifications
   281 may have to be refined after enriching a proof context.
   282 
   283 * Attribute "case_names" has been refined: the assumptions in each case
   284 can be named now by following the case name with [name1 name2 ...].
   285 
   286 * Isabelle/Isar reference manual has been updated and extended:
   287   - "Synopsis" provides a catalog of main Isar language concepts.
   288   - Formal references in syntax diagrams, via @{rail} antiquotation.
   289   - Updated material from classic "ref" manual, notably about
   290     "Classical Reasoner".
   291 
   292 
   293 *** HOL ***
   294 
   295 * Class bot and top require underlying partial order rather than
   296 preorder: uniqueness of bot and top is guaranteed.  INCOMPATIBILITY.
   297 
   298 * Class complete_lattice: generalized a couple of lemmas from sets;
   299 generalized theorems INF_cong and SUP_cong.  New type classes for
   300 complete boolean algebras and complete linear orders.  Lemmas
   301 Inf_less_iff, less_Sup_iff, INF_less_iff, less_SUP_iff now reside in
   302 class complete_linorder.
   303 
   304 Changed proposition of lemmas Inf_bool_def, Sup_bool_def, Inf_fun_def,
   305 Sup_fun_def, Inf_apply, Sup_apply.
   306 
   307 Removed redundant lemmas (the right hand side gives hints how to
   308 replace them for (metis ...), or (simp only: ...) proofs):
   309 
   310   Inf_singleton ~> Inf_insert [where A="{}", unfolded Inf_empty inf_top_right]
   311   Sup_singleton ~> Sup_insert [where A="{}", unfolded Sup_empty sup_bot_right]
   312   Inf_binary ~> Inf_insert, Inf_empty, and inf_top_right
   313   Sup_binary ~> Sup_insert, Sup_empty, and sup_bot_right
   314   Int_eq_Inter ~> Inf_insert, Inf_empty, and inf_top_right
   315   Un_eq_Union ~> Sup_insert, Sup_empty, and sup_bot_right
   316   Inter_def ~> INF_def, image_def
   317   Union_def ~> SUP_def, image_def
   318   INT_eq ~> INF_def, and image_def
   319   UN_eq ~> SUP_def, and image_def
   320   INF_subset ~> INF_superset_mono [OF _ order_refl]
   321 
   322 More consistent and comprehensive names:
   323 
   324   INTER_eq_Inter_image ~> INF_def
   325   UNION_eq_Union_image ~> SUP_def
   326   INFI_def ~> INF_def
   327   SUPR_def ~> SUP_def
   328   INF_leI ~> INF_lower
   329   INF_leI2 ~> INF_lower2
   330   le_INFI ~> INF_greatest
   331   le_SUPI ~> SUP_upper
   332   le_SUPI2 ~> SUP_upper2
   333   SUP_leI ~> SUP_least
   334   INFI_bool_eq ~> INF_bool_eq
   335   SUPR_bool_eq ~> SUP_bool_eq
   336   INFI_apply ~> INF_apply
   337   SUPR_apply ~> SUP_apply
   338   INTER_def ~> INTER_eq
   339   UNION_def ~> UNION_eq
   340 
   341 INCOMPATIBILITY.
   342 
   343 * Renamed theory Complete_Lattice to Complete_Lattices.
   344 INCOMPATIBILITY.
   345 
   346 * Theory Complete_Lattices: lemmas Inf_eq_top_iff, INF_eq_top_iff,
   347 INF_image, Inf_insert, INF_top, Inf_top_conv, INF_top_conv, SUP_bot,
   348 Sup_bot_conv, SUP_bot_conv, Sup_eq_top_iff, SUP_eq_top_iff, SUP_image,
   349 Sup_insert are now declared as [simp].  INCOMPATIBILITY.
   350 
   351 * Theory Lattice: lemmas compl_inf_bot, compl_le_comp_iff,
   352 compl_sup_top, inf_idem, inf_left_idem, inf_sup_absorb, sup_idem,
   353 sup_inf_absob, sup_left_idem are now declared as [simp].  Minor
   354 INCOMPATIBILITY.
   355 
   356 * Added syntactic classes "inf" and "sup" for the respective
   357 constants.  INCOMPATIBILITY: Changes in the argument order of the
   358 (mostly internal) locale predicates for some derived classes.
   359 
   360 * Theorem collections ball_simps and bex_simps do not contain theorems
   361 referring to UNION any longer; these have been moved to collection
   362 UN_ball_bex_simps.  INCOMPATIBILITY.
   363 
   364 * Theory Archimedean_Field: floor now is defined as parameter of a
   365 separate type class floor_ceiling.
   366 
   367 * Theory Finite_Set: more coherent development of fold_set locales:
   368 
   369     locale fun_left_comm ~> locale comp_fun_commute
   370     locale fun_left_comm_idem ~> locale comp_fun_idem
   371 
   372 Both use point-free characterization; interpretation proofs may need
   373 adjustment.  INCOMPATIBILITY.
   374 
   375 * Theory Limits: Type "'a net" has been renamed to "'a filter", in
   376 accordance with standard mathematical terminology. INCOMPATIBILITY.
   377 
   378 * Theory Complex_Main: The locale interpretations for the
   379 bounded_linear and bounded_bilinear locales have been removed, in
   380 order to reduce the number of duplicate lemmas. Users must use the
   381 original names for distributivity theorems, potential INCOMPATIBILITY.
   382 
   383   divide.add ~> add_divide_distrib
   384   divide.diff ~> diff_divide_distrib
   385   divide.setsum ~> setsum_divide_distrib
   386   mult.add_right ~> right_distrib
   387   mult.diff_right ~> right_diff_distrib
   388   mult_right.setsum ~> setsum_right_distrib
   389   mult_left.diff ~> left_diff_distrib
   390 
   391 * Theory Complex_Main: Several redundant theorems have been removed or
   392 replaced by more general versions. INCOMPATIBILITY.
   393 
   394   real_diff_def ~> minus_real_def
   395   real_divide_def ~> divide_real_def
   396   real_less_def ~> less_le
   397   real_abs_def ~> abs_real_def
   398   real_sgn_def ~> sgn_real_def
   399   real_mult_commute ~> mult_commute
   400   real_mult_assoc ~> mult_assoc
   401   real_mult_1 ~> mult_1_left
   402   real_add_mult_distrib ~> left_distrib
   403   real_zero_not_eq_one ~> zero_neq_one
   404   real_mult_inverse_left ~> left_inverse
   405   INVERSE_ZERO ~> inverse_zero
   406   real_le_refl ~> order_refl
   407   real_le_antisym ~> order_antisym
   408   real_le_trans ~> order_trans
   409   real_le_linear ~> linear
   410   real_le_eq_diff ~> le_iff_diff_le_0
   411   real_add_left_mono ~> add_left_mono
   412   real_mult_order ~> mult_pos_pos
   413   real_mult_less_mono2 ~> mult_strict_left_mono
   414   real_of_int_real_of_nat ~> real_of_int_of_nat_eq
   415   real_0_le_divide_iff ~> zero_le_divide_iff
   416   realpow_two_disj ~> power2_eq_iff
   417   real_squared_diff_one_factored ~> square_diff_one_factored
   418   realpow_two_diff ~> square_diff_square_factored
   419   reals_complete2 ~> complete_real
   420   real_sum_squared_expand ~> power2_sum
   421   exp_ln_eq ~> ln_unique
   422   expi_add ~> exp_add
   423   expi_zero ~> exp_zero
   424   lemma_DERIV_subst ~> DERIV_cong
   425   LIMSEQ_Zfun_iff ~> tendsto_Zfun_iff
   426   LIMSEQ_const ~> tendsto_const
   427   LIMSEQ_norm ~> tendsto_norm
   428   LIMSEQ_add ~> tendsto_add
   429   LIMSEQ_minus ~> tendsto_minus
   430   LIMSEQ_minus_cancel ~> tendsto_minus_cancel
   431   LIMSEQ_diff ~> tendsto_diff
   432   bounded_linear.LIMSEQ ~> bounded_linear.tendsto
   433   bounded_bilinear.LIMSEQ ~> bounded_bilinear.tendsto
   434   LIMSEQ_mult ~> tendsto_mult
   435   LIMSEQ_inverse ~> tendsto_inverse
   436   LIMSEQ_divide ~> tendsto_divide
   437   LIMSEQ_pow ~> tendsto_power
   438   LIMSEQ_setsum ~> tendsto_setsum
   439   LIMSEQ_setprod ~> tendsto_setprod
   440   LIMSEQ_norm_zero ~> tendsto_norm_zero_iff
   441   LIMSEQ_rabs_zero ~> tendsto_rabs_zero_iff
   442   LIMSEQ_imp_rabs ~> tendsto_rabs
   443   LIMSEQ_add_minus ~> tendsto_add [OF _ tendsto_minus]
   444   LIMSEQ_add_const ~> tendsto_add [OF _ tendsto_const]
   445   LIMSEQ_diff_const ~> tendsto_diff [OF _ tendsto_const]
   446   LIMSEQ_Complex ~> tendsto_Complex
   447   LIM_ident ~> tendsto_ident_at
   448   LIM_const ~> tendsto_const
   449   LIM_add ~> tendsto_add
   450   LIM_add_zero ~> tendsto_add_zero
   451   LIM_minus ~> tendsto_minus
   452   LIM_diff ~> tendsto_diff
   453   LIM_norm ~> tendsto_norm
   454   LIM_norm_zero ~> tendsto_norm_zero
   455   LIM_norm_zero_cancel ~> tendsto_norm_zero_cancel
   456   LIM_norm_zero_iff ~> tendsto_norm_zero_iff
   457   LIM_rabs ~> tendsto_rabs
   458   LIM_rabs_zero ~> tendsto_rabs_zero
   459   LIM_rabs_zero_cancel ~> tendsto_rabs_zero_cancel
   460   LIM_rabs_zero_iff ~> tendsto_rabs_zero_iff
   461   LIM_compose ~> tendsto_compose
   462   LIM_mult ~> tendsto_mult
   463   LIM_scaleR ~> tendsto_scaleR
   464   LIM_of_real ~> tendsto_of_real
   465   LIM_power ~> tendsto_power
   466   LIM_inverse ~> tendsto_inverse
   467   LIM_sgn ~> tendsto_sgn
   468   isCont_LIM_compose ~> isCont_tendsto_compose
   469   bounded_linear.LIM ~> bounded_linear.tendsto
   470   bounded_linear.LIM_zero ~> bounded_linear.tendsto_zero
   471   bounded_bilinear.LIM ~> bounded_bilinear.tendsto
   472   bounded_bilinear.LIM_prod_zero ~> bounded_bilinear.tendsto_zero
   473   bounded_bilinear.LIM_left_zero ~> bounded_bilinear.tendsto_left_zero
   474   bounded_bilinear.LIM_right_zero ~> bounded_bilinear.tendsto_right_zero
   475   LIM_inverse_fun ~> tendsto_inverse [OF tendsto_ident_at]
   476 
   477 * Theory Complex_Main: The definition of infinite series was
   478 generalized.  Now it is defined on the type class {topological_space,
   479 comm_monoid_add}.  Hence it is useable also for extended real numbers.
   480 
   481 * Theory Complex_Main: The complex exponential function "expi" is now
   482 a type-constrained abbreviation for "exp :: complex => complex"; thus
   483 several polymorphic lemmas about "exp" are now applicable to "expi".
   484 
   485 * Code generation:
   486 
   487   - Theory Library/Code_Char_ord provides native ordering of
   488     characters in the target language.
   489 
   490   - Commands code_module and code_library are legacy, use export_code
   491     instead.
   492 
   493   - Method "evaluation" is legacy, use method "eval" instead.
   494 
   495   - Legacy evaluator "SML" is deactivated by default.  May be
   496     reactivated by the following theory command:
   497 
   498       setup {* Value.add_evaluator ("SML", Codegen.eval_term) *}
   499 
   500 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
   501 
   502 * New proof method "induction" that gives induction hypotheses the
   503 name "IH", thus distinguishing them from further hypotheses that come
   504 from rule induction.  The latter are still called "hyps".  Method
   505 "induction" is a thin wrapper around "induct" and follows the same
   506 syntax.
   507 
   508 * Method "fastsimp" has been renamed to "fastforce", but "fastsimp" is
   509 still available as a legacy feature for some time.
   510 
   511 * Nitpick:
   512   - Added "need" and "total_consts" options.
   513   - Reintroduced "show_skolems" option by popular demand.
   514   - Renamed attribute: nitpick_def ~> nitpick_unfold.
   515     INCOMPATIBILITY.
   516 
   517 * Sledgehammer:
   518   - Use quasi-sound (and efficient) translations by default.
   519   - Added support for the following provers: E-ToFoF, LEO-II,
   520     Satallax, SNARK, Waldmeister, and Z3 with TPTP syntax.
   521   - Automatically preplay and minimize proofs before showing them if
   522     this can be done within reasonable time.
   523   - sledgehammer available_provers ~> sledgehammer supported_provers.
   524     INCOMPATIBILITY.
   525   - Added "preplay_timeout", "slicing", "type_enc", "sound",
   526     "max_mono_iters", and "max_new_mono_instances" options.
   527   - Removed "explicit_apply" and "full_types" options as well as "Full
   528     Types" Proof General menu item. INCOMPATIBILITY.
   529 
   530 * Metis:
   531   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
   532   - Obsoleted "metisFT" -- use "metis (full_types)" instead.
   533     INCOMPATIBILITY.
   534 
   535 * Command 'try':
   536   - Renamed 'try_methods' and added "simp:", "intro:", "dest:", and
   537     "elim:" options. INCOMPATIBILITY.
   538   - Introduced 'try' that not only runs 'try_methods' but also
   539     'solve_direct', 'sledgehammer', 'quickcheck', and 'nitpick'.
   540 
   541 * Quickcheck:
   542   - Added "eval" option to evaluate terms for the found counterexample
   543     (currently only supported by the default (exhaustive) tester).
   544   - Added post-processing of terms to obtain readable counterexamples
   545     (currently only supported by the default (exhaustive) tester).
   546   - New counterexample generator quickcheck[narrowing] enables
   547     narrowing-based testing.  Requires the Glasgow Haskell compiler
   548     with its installation location defined in the Isabelle settings
   549     environment as ISABELLE_GHC.
   550   - Removed quickcheck tester "SML" based on the SML code generator
   551     (formly in HOL/Library).
   552 
   553 * Function package: discontinued option "tailrec".  INCOMPATIBILITY,
   554 use 'partial_function' instead.
   555 
   556 * Theory Library/Extended_Reals replaces now the positive extended
   557 reals found in probability theory. This file is extended by
   558 Multivariate_Analysis/Extended_Real_Limits.
   559 
   560 * Theory Library/Old_Recdef: old 'recdef' package has been moved here,
   561 from where it must be imported explicitly if it is really required.
   562 INCOMPATIBILITY.
   563 
   564 * Theory Library/Wfrec: well-founded recursion combinator "wfrec" has
   565 been moved here.  INCOMPATIBILITY.
   566 
   567 * Theory Library/Saturated provides type of numbers with saturated
   568 arithmetic.
   569 
   570 * Theory Library/Product_Lattice defines a pointwise ordering for the
   571 product type 'a * 'b, and provides instance proofs for various order
   572 and lattice type classes.
   573 
   574 * Theory Library/Countable now provides the "countable_datatype" proof
   575 method for proving "countable" class instances for datatypes.
   576 
   577 * Theory Library/Cset_Monad allows do notation for computable sets
   578 (cset) via the generic monad ad-hoc overloading facility.
   579 
   580 * Library: Theories of common data structures are split into theories
   581 for implementation, an invariant-ensuring type, and connection to an
   582 abstract type. INCOMPATIBILITY.
   583 
   584   - RBT is split into RBT and RBT_Mapping.
   585   - AssocList is split and renamed into AList and AList_Mapping.
   586   - DList is split into DList_Impl, DList, and DList_Cset.
   587   - Cset is split into Cset and List_Cset.
   588 
   589 * Theory Library/Nat_Infinity has been renamed to
   590 Library/Extended_Nat, with name changes of the following types and
   591 constants:
   592 
   593   type inat   ~> type enat
   594   Fin         ~> enat
   595   Infty       ~> infinity (overloaded)
   596   iSuc        ~> eSuc
   597   the_Fin     ~> the_enat
   598 
   599 Every theorem name containing "inat", "Fin", "Infty", or "iSuc" has
   600 been renamed accordingly. INCOMPATIBILITY.
   601 
   602 * Session Multivariate_Analysis: The euclidean_space type class now
   603 fixes a constant "Basis :: 'a set" consisting of the standard
   604 orthonormal basis for the type. Users now have the option of
   605 quantifying over this set instead of using the "basis" function, e.g.
   606 "ALL x:Basis. P x" vs "ALL i<DIM('a). P (basis i)".
   607 
   608 * Session Multivariate_Analysis: Type "('a, 'b) cart" has been renamed
   609 to "('a, 'b) vec" (the syntax "'a ^ 'b" remains unaffected). Constants
   610 "Cart_nth" and "Cart_lambda" have been respectively renamed to
   611 "vec_nth" and "vec_lambda"; theorems mentioning those names have
   612 changed to match. Definition theorems for overloaded constants now use
   613 the standard "foo_vec_def" naming scheme. A few other theorems have
   614 been renamed as follows (INCOMPATIBILITY):
   615 
   616   Cart_eq          ~> vec_eq_iff
   617   dist_nth_le_cart ~> dist_vec_nth_le
   618   tendsto_vector   ~> vec_tendstoI
   619   Cauchy_vector    ~> vec_CauchyI
   620 
   621 * Session Multivariate_Analysis: Several duplicate theorems have been
   622 removed, and other theorems have been renamed or replaced with more
   623 general versions. INCOMPATIBILITY.
   624 
   625   finite_choice ~> finite_set_choice
   626   eventually_conjI ~> eventually_conj
   627   eventually_and ~> eventually_conj_iff
   628   eventually_false ~> eventually_False
   629   setsum_norm ~> norm_setsum
   630   Lim_sequentially ~> LIMSEQ_def
   631   Lim_ident_at ~> LIM_ident
   632   Lim_const ~> tendsto_const
   633   Lim_cmul ~> tendsto_scaleR [OF tendsto_const]
   634   Lim_neg ~> tendsto_minus
   635   Lim_add ~> tendsto_add
   636   Lim_sub ~> tendsto_diff
   637   Lim_mul ~> tendsto_scaleR
   638   Lim_vmul ~> tendsto_scaleR [OF _ tendsto_const]
   639   Lim_null_norm ~> tendsto_norm_zero_iff [symmetric]
   640   Lim_linear ~> bounded_linear.tendsto
   641   Lim_component ~> tendsto_euclidean_component
   642   Lim_component_cart ~> tendsto_vec_nth
   643   Lim_inner ~> tendsto_inner [OF tendsto_const]
   644   dot_lsum ~> inner_setsum_left
   645   dot_rsum ~> inner_setsum_right
   646   continuous_cmul ~> continuous_scaleR [OF continuous_const]
   647   continuous_neg ~> continuous_minus
   648   continuous_sub ~> continuous_diff
   649   continuous_vmul ~> continuous_scaleR [OF _ continuous_const]
   650   continuous_mul ~> continuous_scaleR
   651   continuous_inv ~> continuous_inverse
   652   continuous_at_within_inv ~> continuous_at_within_inverse
   653   continuous_at_inv ~> continuous_at_inverse
   654   continuous_at_norm ~> continuous_norm [OF continuous_at_id]
   655   continuous_at_infnorm ~> continuous_infnorm [OF continuous_at_id]
   656   continuous_at_component ~> continuous_component [OF continuous_at_id]
   657   continuous_on_neg ~> continuous_on_minus
   658   continuous_on_sub ~> continuous_on_diff
   659   continuous_on_cmul ~> continuous_on_scaleR [OF continuous_on_const]
   660   continuous_on_vmul ~> continuous_on_scaleR [OF _ continuous_on_const]
   661   continuous_on_mul ~> continuous_on_scaleR
   662   continuous_on_mul_real ~> continuous_on_mult
   663   continuous_on_inner ~> continuous_on_inner [OF continuous_on_const]
   664   continuous_on_norm ~> continuous_on_norm [OF continuous_on_id]
   665   continuous_on_inverse ~> continuous_on_inv
   666   uniformly_continuous_on_neg ~> uniformly_continuous_on_minus
   667   uniformly_continuous_on_sub ~> uniformly_continuous_on_diff
   668   subset_interior ~> interior_mono
   669   subset_closure ~> closure_mono
   670   closure_univ ~> closure_UNIV
   671   real_arch_lt ~> reals_Archimedean2
   672   real_arch ~> reals_Archimedean3
   673   real_abs_norm ~> abs_norm_cancel
   674   real_abs_sub_norm ~> norm_triangle_ineq3
   675   norm_cauchy_schwarz_abs ~> Cauchy_Schwarz_ineq2
   676 
   677 * Session HOL-Probability:
   678   - Caratheodory's extension lemma is now proved for ring_of_sets.
   679   - Infinite products of probability measures are now available.
   680   - Sigma closure is independent, if the generator is independent
   681   - Use extended reals instead of positive extended
   682     reals. INCOMPATIBILITY.
   683 
   684 * Session HOLCF: Discontinued legacy theorem names, INCOMPATIBILITY.
   685 
   686   expand_fun_below ~> fun_below_iff
   687   below_fun_ext ~> fun_belowI
   688   expand_cfun_eq ~> cfun_eq_iff
   689   ext_cfun ~> cfun_eqI
   690   expand_cfun_below ~> cfun_below_iff
   691   below_cfun_ext ~> cfun_belowI
   692   monofun_fun_fun ~> fun_belowD
   693   monofun_fun_arg ~> monofunE
   694   monofun_lub_fun ~> adm_monofun [THEN admD]
   695   cont_lub_fun ~> adm_cont [THEN admD]
   696   cont2cont_Rep_CFun ~> cont2cont_APP
   697   cont_Rep_CFun_app ~> cont_APP_app
   698   cont_Rep_CFun_app_app ~> cont_APP_app_app
   699   cont_cfun_fun ~> cont_Rep_cfun1 [THEN contE]
   700   cont_cfun_arg ~> cont_Rep_cfun2 [THEN contE]
   701   contlub_cfun ~> lub_APP [symmetric]
   702   contlub_LAM ~> lub_LAM [symmetric]
   703   thelubI ~> lub_eqI
   704   UU_I ~> bottomI
   705   lift_distinct1 ~> lift.distinct(1)
   706   lift_distinct2 ~> lift.distinct(2)
   707   Def_not_UU ~> lift.distinct(2)
   708   Def_inject ~> lift.inject
   709   below_UU_iff ~> below_bottom_iff
   710   eq_UU_iff ~> eq_bottom_iff
   711 
   712 
   713 *** Document preparation ***
   714 
   715 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   716 isar-ref manual, both for description and actual application of the
   717 same.
   718 
   719 * Antiquotation @{value} evaluates the given term and presents its
   720 result.
   721 
   722 * Antiquotations: term style "isub" provides ad-hoc conversion of
   723 variables x1, y23 into subscripted form x\<^isub>1,
   724 y\<^isub>2\<^isub>3.
   725 
   726 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   727 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   728 
   729 * Localized \isabellestyle switch can be used within blocks or groups
   730 like this:
   731 
   732   \isabellestyle{it}  %preferred default
   733   {\isabellestylett @{text "typewriter stuff"}}
   734 
   735 * Discontinued special treatment of hard tabulators.  Implicit
   736 tab-width is now defined as 1.  Potential INCOMPATIBILITY for visual
   737 layouts.
   738 
   739 
   740 *** ML ***
   741 
   742 * The inner syntax of sort/type/term/prop supports inlined YXML
   743 representations within quoted string tokens.  By encoding logical
   744 entities via Term_XML (in ML or Scala) concrete syntax can be
   745 bypassed, which is particularly useful for producing bits of text
   746 under external program control.
   747 
   748 * Antiquotations for ML and document preparation are managed as theory
   749 data, which requires explicit setup.
   750 
   751 * Isabelle_Process.is_active allows tools to check if the official
   752 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
   753 (better known as Proof General).
   754 
   755 * Structure Proof_Context follows standard naming scheme.  Old
   756 ProofContext is still available for some time as legacy alias.
   757 
   758 * Structure Timing provides various operations for timing; supersedes
   759 former start_timing/end_timing etc.
   760 
   761 * Path.print is the official way to show file-system paths to users
   762 (including quotes etc.).
   763 
   764 * Inner syntax: identifiers in parse trees of generic categories
   765 "logic", "aprop", "idt" etc. carry position information (disguised as
   766 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   767 translations that choke on unexpected type constraints.  Positions can
   768 be stripped in ML translations via Syntax.strip_positions /
   769 Syntax.strip_positions_ast, or via the syntax constant
   770 "_strip_positions" within parse trees.  As last resort, positions can
   771 be disabled via the configuration option Syntax.positions, which is
   772 called "syntax_positions" in Isar attribute syntax.
   773 
   774 * Discontinued special status of various ML structures that contribute
   775 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   776 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   777 refer directly to Ast.Constant, Lexicon.is_identifier,
   778 Syntax_Trans.mk_binder_tr etc.
   779 
   780 * Typed print translation: discontinued show_sorts argument, which is
   781 already available via context of "advanced" translation.
   782 
   783 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   784 goal states; body tactic needs to address all subgoals uniformly.
   785 
   786 * Slightly more special eq_list/eq_set, with shortcut involving
   787 pointer equality (assumes that eq relation is reflexive).
   788 
   789 * Classical tactics use proper Proof.context instead of historic types
   790 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   791 operate directly on Proof.context.  Raw type claset retains its use as
   792 snapshot of the classical context, which can be recovered via
   793 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   794 INCOMPATIBILITY, classical tactics and derived proof methods require
   795 proper Proof.context.
   796 
   797 
   798 *** System ***
   799 
   800 * Discontinued support for Poly/ML 5.2, which was the last version
   801 without proper multithreading and TimeLimit implementation.
   802 
   803 * Discontinued old lib/scripts/polyml-platform, which has been
   804 obsolete since Isabelle2009-2.
   805 
   806 * Various optional external tools are referenced more robustly and
   807 uniformly by explicit Isabelle settings as follows:
   808 
   809   ISABELLE_CSDP   (formerly CSDP_EXE)
   810   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
   811   ISABELLE_OCAML  (formerly EXEC_OCAML)
   812   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
   813   ISABELLE_YAP    (formerly EXEC_YAP)
   814 
   815 Note that automated detection from the file-system or search path has
   816 been discontinued.  INCOMPATIBILITY.
   817 
   818 * Scala layer provides JVM method invocation service for static
   819 methods of type (String)String, see Invoke_Scala.method in ML.  For
   820 example:
   821 
   822   Invoke_Scala.method "java.lang.System.getProperty" "java.home"
   823 
   824 Together with YXML.string_of_body/parse_body and XML.Encode/Decode
   825 this allows to pass structured values between ML and Scala.
   826 
   827 * The IsabelleText fonts includes some further glyphs to support the
   828 Prover IDE.  Potential INCOMPATIBILITY: users who happen to have
   829 installed a local copy (which is normally *not* required) need to
   830 delete or update it from ~~/lib/fonts/.
   831 
   832 
   833 
   834 New in Isabelle2011 (January 2011)
   835 ----------------------------------
   836 
   837 *** General ***
   838 
   839 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   840 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   841 useful tooltips and hyperlinks produced from its static analysis.  The
   842 bundled component provides an executable Isabelle tool that can be run
   843 like this:
   844 
   845   Isabelle2011/bin/isabelle jedit
   846 
   847 * Significantly improved Isabelle/Isar implementation manual.
   848 
   849 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   850 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   851 while the default heap location within that directory lacks that extra
   852 suffix.  This isolates multiple Isabelle installations from each
   853 other, avoiding problems with old settings in new versions.
   854 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   855 
   856 * Source files are always encoded as UTF-8, instead of old-fashioned
   857 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   858 the following package declarations:
   859 
   860   \usepackage[utf8]{inputenc}
   861   \usepackage{textcomp}
   862 
   863 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   864 a Unicode character is treated as a single symbol, not a sequence of
   865 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   866 contain symbols without further backslash escapes, Unicode can now be
   867 used here as well.  Recall that Symbol.explode in ML provides a
   868 consistent view on symbols, while raw explode (or String.explode)
   869 merely give a byte-oriented representation.
   870 
   871 * Theory loader: source files are primarily located via the master
   872 directory of each theory node (where the .thy file itself resides).
   873 The global load path is still partially available as legacy feature.
   874 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   875 explicit paths, relatively to the theory.
   876 
   877 * Special treatment of ML file names has been discontinued.
   878 Historically, optional extensions .ML or .sml were added on demand --
   879 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   880 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   881 
   882 * Various options that affect pretty printing etc. are now properly
   883 handled within the context via configuration options, instead of
   884 unsynchronized references or print modes.  There are both ML Config.T
   885 entities and Isar declaration attributes to access these.
   886 
   887   ML (Config.T)                 Isar (attribute)
   888 
   889   eta_contract                  eta_contract
   890   show_brackets                 show_brackets
   891   show_sorts                    show_sorts
   892   show_types                    show_types
   893   show_question_marks           show_question_marks
   894   show_consts                   show_consts
   895   show_abbrevs                  show_abbrevs
   896 
   897   Syntax.ast_trace              syntax_ast_trace
   898   Syntax.ast_stat               syntax_ast_stat
   899   Syntax.ambiguity_level        syntax_ambiguity_level
   900 
   901   Goal_Display.goals_limit      goals_limit
   902   Goal_Display.show_main_goal   show_main_goal
   903 
   904   Method.rule_trace             rule_trace
   905 
   906   Thy_Output.display            thy_output_display
   907   Thy_Output.quotes             thy_output_quotes
   908   Thy_Output.indent             thy_output_indent
   909   Thy_Output.source             thy_output_source
   910   Thy_Output.break              thy_output_break
   911 
   912 Note that corresponding "..._default" references in ML may only be
   913 changed globally at the ROOT session setup, but *not* within a theory.
   914 The option "show_abbrevs" supersedes the former print mode
   915 "no_abbrevs" with inverted meaning.
   916 
   917 * More systematic naming of some configuration options.
   918 INCOMPATIBILITY.
   919 
   920   trace_simp  ~>  simp_trace
   921   debug_simp  ~>  simp_debug
   922 
   923 * Support for real valued configuration options, using simplistic
   924 floating-point notation that coincides with the inner syntax for
   925 float_token.
   926 
   927 * Support for real valued preferences (with approximative PGIP type):
   928 front-ends need to accept "pgint" values in float notation.
   929 INCOMPATIBILITY.
   930 
   931 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   932 DejaVu Sans.
   933 
   934 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   935 
   936 
   937 *** Pure ***
   938 
   939 * Command 'type_synonym' (with single argument) replaces somewhat
   940 outdated 'types', which is still available as legacy feature for some
   941 time.
   942 
   943 * Command 'nonterminal' (with 'and' separated list of arguments)
   944 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   945 
   946 * Command 'notepad' replaces former 'example_proof' for
   947 experimentation in Isar without any result.  INCOMPATIBILITY.
   948 
   949 * Locale interpretation commands 'interpret' and 'sublocale' accept
   950 lists of equations to map definitions in a locale to appropriate
   951 entities in the context of the interpretation.  The 'interpretation'
   952 command already provided this functionality.
   953 
   954 * Diagnostic command 'print_dependencies' prints the locale instances
   955 that would be activated if the specified expression was interpreted in
   956 the current context.  Variant "print_dependencies!" assumes a context
   957 without interpretations.
   958 
   959 * Diagnostic command 'print_interps' prints interpretations in proofs
   960 in addition to interpretations in theories.
   961 
   962 * Discontinued obsolete 'global' and 'local' commands to manipulate
   963 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   964 Sign.root_path and Sign.local_path may be applied directly where this
   965 feature is still required for historical reasons.
   966 
   967 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   968 'definition' instead.
   969 
   970 * The "prems" fact, which refers to the accidental collection of
   971 foundational premises in the context, is now explicitly marked as
   972 legacy feature and will be discontinued soon.  Consider using "assms"
   973 of the head statement or reference facts by explicit names.
   974 
   975 * Document antiquotations @{class} and @{type} print classes and type
   976 constructors.
   977 
   978 * Document antiquotation @{file} checks file/directory entries within
   979 the local file system.
   980 
   981 
   982 *** HOL ***
   983 
   984 * Coercive subtyping: functions can be declared as coercions and type
   985 inference will add them as necessary upon input of a term.  Theory
   986 Complex_Main declares real :: nat => real and real :: int => real as
   987 coercions. A coercion function f is declared like this:
   988 
   989   declare [[coercion f]]
   990 
   991 To lift coercions through type constructors (e.g. from nat => real to
   992 nat list => real list), map functions can be declared, e.g.
   993 
   994   declare [[coercion_map map]]
   995 
   996 Currently coercion inference is activated only in theories including
   997 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   998 the configuration option "coercion_enabled", e.g. it can be enabled in
   999 other theories like this:
  1000 
  1001   declare [[coercion_enabled]]
  1002 
  1003 * Command 'partial_function' provides basic support for recursive
  1004 function definitions over complete partial orders.  Concrete instances
  1005 are provided for i) the option type, ii) tail recursion on arbitrary
  1006 types, and iii) the heap monad of Imperative_HOL.  See
  1007 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
  1008 for examples.
  1009 
  1010 * Function package: f.psimps rules are no longer implicitly declared
  1011 as [simp].  INCOMPATIBILITY.
  1012 
  1013 * Datatype package: theorems generated for executable equality (class
  1014 "eq") carry proper names and are treated as default code equations.
  1015 
  1016 * Inductive package: now offers command 'inductive_simps' to
  1017 automatically derive instantiated and simplified equations for
  1018 inductive predicates, similar to 'inductive_cases'.
  1019 
  1020 * Command 'enriched_type' allows to register properties of the
  1021 functorial structure of types.
  1022 
  1023 * Improved infrastructure for term evaluation using code generator
  1024 techniques, in particular static evaluation conversions.
  1025 
  1026 * Code generator: Scala (2.8 or higher) has been added to the target
  1027 languages.
  1028 
  1029 * Code generator: globbing constant expressions "*" and "Theory.*"
  1030 have been replaced by the more idiomatic "_" and "Theory._".
  1031 INCOMPATIBILITY.
  1032 
  1033 * Code generator: export_code without explicit file declaration prints
  1034 to standard output.  INCOMPATIBILITY.
  1035 
  1036 * Code generator: do not print function definitions for case
  1037 combinators any longer.
  1038 
  1039 * Code generator: simplification with rules determined with
  1040 src/Tools/Code/code_simp.ML and method "code_simp".
  1041 
  1042 * Code generator for records: more idiomatic representation of record
  1043 types.  Warning: records are not covered by ancient SML code
  1044 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
  1045 rep_datatype declaration helps to succeed then:
  1046 
  1047   record 'a foo = ...
  1048   ...
  1049   rep_datatype foo_ext ...
  1050 
  1051 * Records: logical foundation type for records does not carry a
  1052 '_type' suffix any longer (obsolete due to authentic syntax).
  1053 INCOMPATIBILITY.
  1054 
  1055 * Quickcheck now by default uses exhaustive testing instead of random
  1056 testing.  Random testing can be invoked by "quickcheck [random]",
  1057 exhaustive testing by "quickcheck [exhaustive]".
  1058 
  1059 * Quickcheck instantiates polymorphic types with small finite
  1060 datatypes by default. This enables a simple execution mechanism to
  1061 handle quantifiers and function equality over the finite datatypes.
  1062 
  1063 * Quickcheck random generator has been renamed from "code" to
  1064 "random".  INCOMPATIBILITY.
  1065 
  1066 * Quickcheck now has a configurable time limit which is set to 30
  1067 seconds by default. This can be changed by adding [timeout = n] to the
  1068 quickcheck command. The time limit for Auto Quickcheck is still set
  1069 independently.
  1070 
  1071 * Quickcheck in locales considers interpretations of that locale for
  1072 counter example search.
  1073 
  1074 * Sledgehammer:
  1075   - Added "smt" and "remote_smt" provers based on the "smt" proof
  1076     method. See the Sledgehammer manual for details ("isabelle doc
  1077     sledgehammer").
  1078   - Renamed commands:
  1079     sledgehammer atp_info ~> sledgehammer running_provers
  1080     sledgehammer atp_kill ~> sledgehammer kill_provers
  1081     sledgehammer available_atps ~> sledgehammer available_provers
  1082     INCOMPATIBILITY.
  1083   - Renamed options:
  1084     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
  1085     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
  1086     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
  1087     (and "ms" and "min" are no longer supported)
  1088     INCOMPATIBILITY.
  1089 
  1090 * Nitpick:
  1091   - Renamed options:
  1092     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
  1093     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
  1094     INCOMPATIBILITY.
  1095   - Added support for partial quotient types.
  1096   - Added local versions of the "Nitpick.register_xxx" functions.
  1097   - Added "whack" option.
  1098   - Allow registration of quotient types as codatatypes.
  1099   - Improved "merge_type_vars" option to merge more types.
  1100   - Removed unsound "fast_descrs" option.
  1101   - Added custom symmetry breaking for datatypes, making it possible to reach
  1102     higher cardinalities.
  1103   - Prevent the expansion of too large definitions.
  1104 
  1105 * Proof methods "metis" and "meson" now have configuration options
  1106 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
  1107 to diagnose these tools. E.g.
  1108 
  1109     using [[metis_trace = true]]
  1110 
  1111 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
  1112 manually as command 'solve_direct'.
  1113 
  1114 * The default SMT solver Z3 must be enabled explicitly (due to
  1115 licensing issues) by setting the environment variable
  1116 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
  1117 commercial applications, the SMT solver CVC3 is provided as fall-back;
  1118 changing the SMT solver is done via the configuration option
  1119 "smt_solver".
  1120 
  1121 * Remote SMT solvers need to be referred to by the "remote_" prefix,
  1122 i.e. "remote_cvc3" and "remote_z3".
  1123 
  1124 * Added basic SMT support for datatypes, records, and typedefs using
  1125 the oracle mode (no proofs).  Direct support of pairs has been dropped
  1126 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
  1127 support for a similar behavior).  Minor INCOMPATIBILITY.
  1128 
  1129 * Changed SMT configuration options:
  1130   - Renamed:
  1131     z3_proofs ~> smt_oracle (with inverted meaning)
  1132     z3_trace_assms ~> smt_trace_used_facts
  1133     INCOMPATIBILITY.
  1134   - Added:
  1135     smt_verbose
  1136     smt_random_seed
  1137     smt_datatypes
  1138     smt_infer_triggers
  1139     smt_monomorph_limit
  1140     cvc3_options
  1141     remote_cvc3_options
  1142     remote_z3_options
  1143     yices_options
  1144 
  1145 * Boogie output files (.b2i files) need to be declared in the theory
  1146 header.
  1147 
  1148 * Simplification procedure "list_to_set_comprehension" rewrites list
  1149 comprehensions applied to List.set to set comprehensions.  Occasional
  1150 INCOMPATIBILITY, may be deactivated like this:
  1151 
  1152   declare [[simproc del: list_to_set_comprehension]]
  1153 
  1154 * Removed old version of primrec package.  INCOMPATIBILITY.
  1155 
  1156 * Removed simplifier congruence rule of "prod_case", as has for long
  1157 been the case with "split".  INCOMPATIBILITY.
  1158 
  1159 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
  1160 
  1161 * Removed [split_format ... and ... and ...] version of
  1162 [split_format].  Potential INCOMPATIBILITY.
  1163 
  1164 * Predicate "sorted" now defined inductively, with nice induction
  1165 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
  1166 
  1167 * Constant "contents" renamed to "the_elem", to free the generic name
  1168 contents for other uses.  INCOMPATIBILITY.
  1169 
  1170 * Renamed class eq and constant eq (for code generation) to class
  1171 equal and constant equal, plus renaming of related facts and various
  1172 tuning.  INCOMPATIBILITY.
  1173 
  1174 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
  1175 
  1176 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
  1177 INCOMPATIBILITY.
  1178 
  1179 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
  1180 avoid confusion with finite sets.  INCOMPATIBILITY.
  1181 
  1182 * Abandoned locales equiv, congruent and congruent2 for equivalence
  1183 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
  1184 for congruent(2)).
  1185 
  1186 * Some previously unqualified names have been qualified:
  1187 
  1188   types
  1189     bool ~> HOL.bool
  1190     nat ~> Nat.nat
  1191 
  1192   constants
  1193     Trueprop ~> HOL.Trueprop
  1194     True ~> HOL.True
  1195     False ~> HOL.False
  1196     op & ~> HOL.conj
  1197     op | ~> HOL.disj
  1198     op --> ~> HOL.implies
  1199     op = ~> HOL.eq
  1200     Not ~> HOL.Not
  1201     The ~> HOL.The
  1202     All ~> HOL.All
  1203     Ex ~> HOL.Ex
  1204     Ex1 ~> HOL.Ex1
  1205     Let ~> HOL.Let
  1206     If ~> HOL.If
  1207     Ball ~> Set.Ball
  1208     Bex ~> Set.Bex
  1209     Suc ~> Nat.Suc
  1210     Pair ~> Product_Type.Pair
  1211     fst ~> Product_Type.fst
  1212     snd ~> Product_Type.snd
  1213     curry ~> Product_Type.curry
  1214     op : ~> Set.member
  1215     Collect ~> Set.Collect
  1216 
  1217 INCOMPATIBILITY.
  1218 
  1219 * More canonical naming convention for some fundamental definitions:
  1220 
  1221     bot_bool_eq ~> bot_bool_def
  1222     top_bool_eq ~> top_bool_def
  1223     inf_bool_eq ~> inf_bool_def
  1224     sup_bool_eq ~> sup_bool_def
  1225     bot_fun_eq  ~> bot_fun_def
  1226     top_fun_eq  ~> top_fun_def
  1227     inf_fun_eq  ~> inf_fun_def
  1228     sup_fun_eq  ~> sup_fun_def
  1229 
  1230 INCOMPATIBILITY.
  1231 
  1232 * More stylized fact names:
  1233 
  1234   expand_fun_eq ~> fun_eq_iff
  1235   expand_set_eq ~> set_eq_iff
  1236   set_ext       ~> set_eqI
  1237   nat_number    ~> eval_nat_numeral
  1238 
  1239 INCOMPATIBILITY.
  1240 
  1241 * Refactoring of code-generation specific operations in theory List:
  1242 
  1243   constants
  1244     null ~> List.null
  1245 
  1246   facts
  1247     mem_iff ~> member_def
  1248     null_empty ~> null_def
  1249 
  1250 INCOMPATIBILITY.  Note that these were not supposed to be used
  1251 regularly unless for striking reasons; their main purpose was code
  1252 generation.
  1253 
  1254 Various operations from the Haskell prelude are used for generating
  1255 Haskell code.
  1256 
  1257 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
  1258 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
  1259 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
  1260 
  1261 * Abolished some non-alphabetic type names: "prod" and "sum" replace
  1262 "*" and "+" respectively.  INCOMPATIBILITY.
  1263 
  1264 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
  1265 "Sum_Type.Plus" instead.
  1266 
  1267 * Constant "split" has been merged with constant "prod_case"; names of
  1268 ML functions, facts etc. involving split have been retained so far,
  1269 though.  INCOMPATIBILITY.
  1270 
  1271 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
  1272 instead.  INCOMPATIBILITY.
  1273 
  1274 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
  1275 INCOMPATIBILITY.
  1276 
  1277 * Former theory Library/Enum is now part of the HOL-Main image.
  1278 INCOMPATIBILITY: all constants of the Enum theory now have to be
  1279 referred to by its qualified name.
  1280 
  1281   enum    ~>  Enum.enum
  1282   nlists  ~>  Enum.nlists
  1283   product ~>  Enum.product
  1284 
  1285 * Theory Library/Monad_Syntax provides do-syntax for monad types.
  1286 Syntax in Library/State_Monad has been changed to avoid ambiguities.
  1287 INCOMPATIBILITY.
  1288 
  1289 * Theory Library/SetsAndFunctions has been split into
  1290 Library/Function_Algebras and Library/Set_Algebras; canonical names
  1291 for instance definitions for functions; various improvements.
  1292 INCOMPATIBILITY.
  1293 
  1294 * Theory Library/Multiset provides stable quicksort implementation of
  1295 sort_key.
  1296 
  1297 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
  1298 INCOMPATIBILITY.
  1299 
  1300 * Session Multivariate_Analysis: introduced a type class for euclidean
  1301 space.  Most theorems are now stated in terms of euclidean spaces
  1302 instead of finite cartesian products.
  1303 
  1304   types
  1305     real ^ 'n ~>  'a::real_vector
  1306               ~>  'a::euclidean_space
  1307               ~>  'a::ordered_euclidean_space
  1308         (depends on your needs)
  1309 
  1310   constants
  1311      _ $ _        ~> _ $$ _
  1312      \<chi> x. _  ~> \<chi>\<chi> x. _
  1313      CARD('n)     ~> DIM('a)
  1314 
  1315 Also note that the indices are now natural numbers and not from some
  1316 finite type. Finite cartesian products of euclidean spaces, products
  1317 of euclidean spaces the real and complex numbers are instantiated to
  1318 be euclidean_spaces.  INCOMPATIBILITY.
  1319 
  1320 * Session Probability: introduced pextreal as positive extended real
  1321 numbers.  Use pextreal as value for measures.  Introduce the
  1322 Radon-Nikodym derivative, product spaces and Fubini's theorem for
  1323 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
  1324 the integral in Multivariate Analysis.  INCOMPATIBILITY.
  1325 
  1326 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
  1327 INCOMPATIBILITY.
  1328 
  1329 * Session SPARK (with image HOL-SPARK) provides commands to load and
  1330 prove verification conditions generated by the SPARK Ada program
  1331 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
  1332 
  1333 
  1334 *** HOL-Algebra ***
  1335 
  1336 * Theorems for additive ring operations (locale abelian_monoid and
  1337 descendants) are generated by interpretation from their multiplicative
  1338 counterparts.  Names (in particular theorem names) have the mandatory
  1339 qualifier 'add'.  Previous theorem names are redeclared for
  1340 compatibility.
  1341 
  1342 * Structure "int_ring" is now an abbreviation (previously a
  1343 definition).  This fits more natural with advanced interpretations.
  1344 
  1345 
  1346 *** HOLCF ***
  1347 
  1348 * The domain package now runs in definitional mode by default: The
  1349 former command 'new_domain' is now called 'domain'.  To use the domain
  1350 package in its original axiomatic mode, use 'domain (unsafe)'.
  1351 INCOMPATIBILITY.
  1352 
  1353 * The new class "domain" is now the default sort.  Class "predomain"
  1354 is an unpointed version of "domain". Theories can be updated by
  1355 replacing sort annotations as shown below.  INCOMPATIBILITY.
  1356 
  1357   'a::type ~> 'a::countable
  1358   'a::cpo  ~> 'a::predomain
  1359   'a::pcpo ~> 'a::domain
  1360 
  1361 * The old type class "rep" has been superseded by class "domain".
  1362 Accordingly, users of the definitional package must remove any
  1363 "default_sort rep" declarations.  INCOMPATIBILITY.
  1364 
  1365 * The domain package (definitional mode) now supports unpointed
  1366 predomain argument types, as long as they are marked 'lazy'. (Strict
  1367 arguments must be in class "domain".) For example, the following
  1368 domain definition now works:
  1369 
  1370   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
  1371 
  1372 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
  1373 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
  1374 'a option, and 'a list.  Additionally, it configures fixrec and the
  1375 domain package to work with these types.  For example:
  1376 
  1377   fixrec isInl :: "('a + 'b) u -> tr"
  1378     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
  1379 
  1380   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
  1381 
  1382 * The "(permissive)" option of fixrec has been replaced with a
  1383 per-equation "(unchecked)" option. See
  1384 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
  1385 
  1386 * The "bifinite" class no longer fixes a constant "approx"; the class
  1387 now just asserts that such a function exists.  INCOMPATIBILITY.
  1388 
  1389 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
  1390 defines an embedding of type 'a defl into udom by default; instances
  1391 of "bifinite" and "domain" classes are available in
  1392 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
  1393 
  1394 * The syntax "REP('a)" has been replaced with "DEFL('a)".
  1395 
  1396 * The predicate "directed" has been removed.  INCOMPATIBILITY.
  1397 
  1398 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
  1399 
  1400 * The function "cprod_map" has been renamed to "prod_map".
  1401 INCOMPATIBILITY.
  1402 
  1403 * The monadic bind operator on each powerdomain has new binder syntax
  1404 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
  1405 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
  1406 
  1407 * The infix syntax for binary union on each powerdomain has changed
  1408 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
  1409 syntax.  INCOMPATIBILITY.
  1410 
  1411 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
  1412 still supported as an input translation.
  1413 
  1414 * Renamed some theorems (the original names are also still available).
  1415 
  1416   expand_fun_below   ~> fun_below_iff
  1417   below_fun_ext      ~> fun_belowI
  1418   expand_cfun_eq     ~> cfun_eq_iff
  1419   ext_cfun           ~> cfun_eqI
  1420   expand_cfun_below  ~> cfun_below_iff
  1421   below_cfun_ext     ~> cfun_belowI
  1422   cont2cont_Rep_CFun ~> cont2cont_APP
  1423 
  1424 * The Abs and Rep functions for various types have changed names.
  1425 Related theorem names have also changed to match. INCOMPATIBILITY.
  1426 
  1427   Rep_CFun  ~> Rep_cfun
  1428   Abs_CFun  ~> Abs_cfun
  1429   Rep_Sprod ~> Rep_sprod
  1430   Abs_Sprod ~> Abs_sprod
  1431   Rep_Ssum  ~> Rep_ssum
  1432   Abs_Ssum  ~> Abs_ssum
  1433 
  1434 * Lemmas with names of the form *_defined_iff or *_strict_iff have
  1435 been renamed to *_bottom_iff.  INCOMPATIBILITY.
  1436 
  1437 * Various changes to bisimulation/coinduction with domain package:
  1438 
  1439   - Definitions of "bisim" constants no longer mention definedness.
  1440   - With mutual recursion, "bisim" predicate is now curried.
  1441   - With mutual recursion, each type gets a separate coind theorem.
  1442   - Variable names in bisim_def and coinduct rules have changed.
  1443 
  1444 INCOMPATIBILITY.
  1445 
  1446 * Case combinators generated by the domain package for type "foo" are
  1447 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
  1448 
  1449 * Several theorems have been renamed to more accurately reflect the
  1450 names of constants and types involved.  INCOMPATIBILITY.
  1451 
  1452   thelub_const    ~> lub_const
  1453   lub_const       ~> is_lub_const
  1454   thelubI         ~> lub_eqI
  1455   is_lub_lub      ~> is_lubD2
  1456   lubI            ~> is_lub_lub
  1457   unique_lub      ~> is_lub_unique
  1458   is_ub_lub       ~> is_lub_rangeD1
  1459   lub_bin_chain   ~> is_lub_bin_chain
  1460   lub_fun         ~> is_lub_fun
  1461   thelub_fun      ~> lub_fun
  1462   thelub_cfun     ~> lub_cfun
  1463   thelub_Pair     ~> lub_Pair
  1464   lub_cprod       ~> is_lub_prod
  1465   thelub_cprod    ~> lub_prod
  1466   minimal_cprod   ~> minimal_prod
  1467   inst_cprod_pcpo ~> inst_prod_pcpo
  1468   UU_I            ~> bottomI
  1469   compact_UU      ~> compact_bottom
  1470   deflation_UU    ~> deflation_bottom
  1471   finite_deflation_UU ~> finite_deflation_bottom
  1472 
  1473 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
  1474 
  1475   sq_ord_less_eq_trans ~> below_eq_trans
  1476   sq_ord_eq_less_trans ~> eq_below_trans
  1477   refl_less            ~> below_refl
  1478   trans_less           ~> below_trans
  1479   antisym_less         ~> below_antisym
  1480   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
  1481   box_less             ~> box_below
  1482   rev_trans_less       ~> rev_below_trans
  1483   not_less2not_eq      ~> not_below2not_eq
  1484   less_UU_iff          ~> below_UU_iff
  1485   flat_less_iff        ~> flat_below_iff
  1486   adm_less             ~> adm_below
  1487   adm_not_less         ~> adm_not_below
  1488   adm_compact_not_less ~> adm_compact_not_below
  1489   less_fun_def         ~> below_fun_def
  1490   expand_fun_less      ~> fun_below_iff
  1491   less_fun_ext         ~> fun_belowI
  1492   less_discr_def       ~> below_discr_def
  1493   discr_less_eq        ~> discr_below_eq
  1494   less_unit_def        ~> below_unit_def
  1495   less_cprod_def       ~> below_prod_def
  1496   prod_lessI           ~> prod_belowI
  1497   Pair_less_iff        ~> Pair_below_iff
  1498   fst_less_iff         ~> fst_below_iff
  1499   snd_less_iff         ~> snd_below_iff
  1500   expand_cfun_less     ~> cfun_below_iff
  1501   less_cfun_ext        ~> cfun_belowI
  1502   injection_less       ~> injection_below
  1503   less_up_def          ~> below_up_def
  1504   not_Iup_less         ~> not_Iup_below
  1505   Iup_less             ~> Iup_below
  1506   up_less              ~> up_below
  1507   Def_inject_less_eq   ~> Def_below_Def
  1508   Def_less_is_eq       ~> Def_below_iff
  1509   spair_less_iff       ~> spair_below_iff
  1510   less_sprod           ~> below_sprod
  1511   spair_less           ~> spair_below
  1512   sfst_less_iff        ~> sfst_below_iff
  1513   ssnd_less_iff        ~> ssnd_below_iff
  1514   fix_least_less       ~> fix_least_below
  1515   dist_less_one        ~> dist_below_one
  1516   less_ONE             ~> below_ONE
  1517   ONE_less_iff         ~> ONE_below_iff
  1518   less_sinlD           ~> below_sinlD
  1519   less_sinrD           ~> below_sinrD
  1520 
  1521 
  1522 *** FOL and ZF ***
  1523 
  1524 * All constant names are now qualified internally and use proper
  1525 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
  1526 
  1527 
  1528 *** ML ***
  1529 
  1530 * Antiquotation @{assert} inlines a function bool -> unit that raises
  1531 Fail if the argument is false.  Due to inlining the source position of
  1532 failed assertions is included in the error output.
  1533 
  1534 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
  1535 text is in practice always evaluated with a stable theory checkpoint.
  1536 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
  1537 
  1538 * Antiquotation @{theory A} refers to theory A from the ancestry of
  1539 the current context, not any accidental theory loader state as before.
  1540 Potential INCOMPATIBILITY, subtle change in semantics.
  1541 
  1542 * Syntax.pretty_priority (default 0) configures the required priority
  1543 of pretty-printed output and thus affects insertion of parentheses.
  1544 
  1545 * Syntax.default_root (default "any") configures the inner syntax
  1546 category (nonterminal symbol) for parsing of terms.
  1547 
  1548 * Former exception Library.UnequalLengths now coincides with
  1549 ListPair.UnequalLengths.
  1550 
  1551 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
  1552 main functionality is provided by structure Simplifier.
  1553 
  1554 * Renamed raw "explode" function to "raw_explode" to emphasize its
  1555 meaning.  Note that internally to Isabelle, Symbol.explode is used in
  1556 almost all situations.
  1557 
  1558 * Discontinued obsolete function sys_error and exception SYS_ERROR.
  1559 See implementation manual for further details on exceptions in
  1560 Isabelle/ML.
  1561 
  1562 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
  1563 meaning.
  1564 
  1565 * Renamed structure PureThy to Pure_Thy and moved most of its
  1566 operations to structure Global_Theory, to emphasize that this is
  1567 rarely-used global-only stuff.
  1568 
  1569 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
  1570 instead (or tracing for high-volume output).
  1571 
  1572 * Configuration option show_question_marks only affects regular pretty
  1573 printing of types and terms, not raw Term.string_of_vname.
  1574 
  1575 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
  1576 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
  1577 @{thms} for most purposes.
  1578 
  1579 * ML structure Unsynchronized is never opened, not even in Isar
  1580 interaction mode as before.  Old Unsynchronized.set etc. have been
  1581 discontinued -- use plain := instead.  This should be *rare* anyway,
  1582 since modern tools always work via official context data, notably
  1583 configuration options.
  1584 
  1585 * Parallel and asynchronous execution requires special care concerning
  1586 interrupts.  Structure Exn provides some convenience functions that
  1587 avoid working directly with raw Interrupt.  User code must not absorb
  1588 interrupts -- intermediate handling (for cleanup etc.) needs to be
  1589 followed by re-raising of the original exception.  Another common
  1590 source of mistakes are "handle _" patterns, which make the meaning of
  1591 the program subject to physical effects of the environment.
  1592 
  1593 
  1594 
  1595 New in Isabelle2009-2 (June 2010)
  1596 ---------------------------------
  1597 
  1598 *** General ***
  1599 
  1600 * Authentic syntax for *all* logical entities (type classes, type
  1601 constructors, term constants): provides simple and robust
  1602 correspondence between formal entities and concrete syntax.  Within
  1603 the parse tree / AST representations, "constants" are decorated by
  1604 their category (class, type, const) and spelled out explicitly with
  1605 their full internal name.
  1606 
  1607 Substantial INCOMPATIBILITY concerning low-level syntax declarations
  1608 and translations (translation rules and translation functions in ML).
  1609 Some hints on upgrading:
  1610 
  1611   - Many existing uses of 'syntax' and 'translations' can be replaced
  1612     by more modern 'type_notation', 'notation' and 'abbreviation',
  1613     which are independent of this issue.
  1614 
  1615   - 'translations' require markup within the AST; the term syntax
  1616     provides the following special forms:
  1617 
  1618       CONST c   -- produces syntax version of constant c from context
  1619       XCONST c  -- literally c, checked as constant from context
  1620       c         -- literally c, if declared by 'syntax'
  1621 
  1622     Plain identifiers are treated as AST variables -- occasionally the
  1623     system indicates accidental variables via the error "rhs contains
  1624     extra variables".
  1625 
  1626     Type classes and type constructors are marked according to their
  1627     concrete syntax.  Some old translations rules need to be written
  1628     for the "type" category, using type constructor application
  1629     instead of pseudo-term application of the default category
  1630     "logic".
  1631 
  1632   - 'parse_translation' etc. in ML may use the following
  1633     antiquotations:
  1634 
  1635       @{class_syntax c}   -- type class c within parse tree / AST
  1636       @{term_syntax c}    -- type constructor c within parse tree / AST
  1637       @{const_syntax c}   -- ML version of "CONST c" above
  1638       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1639 
  1640   - Literal types within 'typed_print_translations', i.e. those *not*
  1641     represented as pseudo-terms are represented verbatim.  Use @{class
  1642     c} or @{type_name c} here instead of the above syntax
  1643     antiquotations.
  1644 
  1645 Note that old non-authentic syntax was based on unqualified base
  1646 names, so all of the above "constant" names would coincide.  Recall
  1647 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1648 diagnose syntax problems.
  1649 
  1650 * Type constructors admit general mixfix syntax, not just infix.
  1651 
  1652 * Concrete syntax may be attached to local entities without a proof
  1653 body, too.  This works via regular mixfix annotations for 'fix',
  1654 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1655 similar to the 'notation' command in theory specifications.
  1656 
  1657 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1658 need to specify constant name and syntax separately.  Internal ML
  1659 datatype constructors have been renamed from InfixName to Infix etc.
  1660 Minor INCOMPATIBILITY.
  1661 
  1662 * Schematic theorem statements need to be explicitly markup as such,
  1663 via commands 'schematic_lemma', 'schematic_theorem',
  1664 'schematic_corollary'.  Thus the relevance of the proof is made
  1665 syntactically clear, which impacts performance in a parallel or
  1666 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1667 
  1668 * Use of cumulative prems via "!" in some proof methods has been
  1669 discontinued (old legacy feature).
  1670 
  1671 * References 'trace_simp' and 'debug_simp' have been replaced by
  1672 configuration options stored in the context. Enabling tracing (the
  1673 case of debugging is similar) in proofs works via
  1674 
  1675   using [[trace_simp = true]]
  1676 
  1677 Tracing is then active for all invocations of the simplifier in
  1678 subsequent goal refinement steps. Tracing may also still be enabled or
  1679 disabled via the ProofGeneral settings menu.
  1680 
  1681 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1682 'hide_fact' replace the former 'hide' KIND command.  Minor
  1683 INCOMPATIBILITY.
  1684 
  1685 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1686 more efficient than combinations with -q1 or -q2.
  1687 
  1688 
  1689 *** Pure ***
  1690 
  1691 * Proofterms record type-class reasoning explicitly, using the
  1692 "unconstrain" operation internally.  This eliminates all sort
  1693 constraints from a theorem and proof, introducing explicit
  1694 OFCLASS-premises.  On the proof term level, this operation is
  1695 automatically applied at theorem boundaries, such that closed proofs
  1696 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1697 inspect proof terms.
  1698 
  1699 * Local theory specifications may depend on extra type variables that
  1700 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1701 are added internally.  For example:
  1702 
  1703   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1704 
  1705 * Predicates of locales introduced by classes carry a mandatory
  1706 "class" prefix.  INCOMPATIBILITY.
  1707 
  1708 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1709 
  1710 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1711 'class' instead.
  1712 
  1713 * Command 'code_reflect' allows to incorporate generated ML code into
  1714 runtime environment; replaces immature code_datatype antiquotation.
  1715 INCOMPATIBILITY.
  1716 
  1717 * Code generator: simple concept for abstract datatypes obeying
  1718 invariants.
  1719 
  1720 * Code generator: details of internal data cache have no impact on the
  1721 user space functionality any longer.
  1722 
  1723 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1724 subgoals.  This is more appropriate for interpretations with 'where'.
  1725 INCOMPATIBILITY.
  1726 
  1727 * Command 'example_proof' opens an empty proof body.  This allows to
  1728 experiment with Isar, without producing any persistent result.
  1729 
  1730 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1731 within a local theory context, with explicit checking of the
  1732 constructors involved (in contrast to the raw 'syntax' versions).
  1733 
  1734 * Commands 'types' and 'typedecl' now work within a local theory
  1735 context -- without introducing dependencies on parameters or
  1736 assumptions, which is not possible in Isabelle/Pure.
  1737 
  1738 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1739 within a local theory context.  Minor INCOMPATIBILITY.
  1740 
  1741 
  1742 *** HOL ***
  1743 
  1744 * Command 'typedef' now works within a local theory context -- without
  1745 introducing dependencies on parameters or assumptions, which is not
  1746 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1747 contain multiple interpretations of local typedefs (with different
  1748 non-emptiness proofs), even in a global theory context.
  1749 
  1750 * New package for quotient types.  Commands 'quotient_type' and
  1751 'quotient_definition' may be used for defining types and constants by
  1752 quotient constructions.  An example is the type of integers created by
  1753 quotienting pairs of natural numbers:
  1754 
  1755   fun
  1756     intrel :: "(nat * nat) => (nat * nat) => bool"
  1757   where
  1758     "intrel (x, y) (u, v) = (x + v = u + y)"
  1759 
  1760   quotient_type int = "nat * nat" / intrel
  1761     by (auto simp add: equivp_def expand_fun_eq)
  1762 
  1763   quotient_definition
  1764     "0::int" is "(0::nat, 0::nat)"
  1765 
  1766 The method "lifting" can be used to lift of theorems from the
  1767 underlying "raw" type to the quotient type.  The example
  1768 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1769 construction and provides a reasoning infrastructure for finite sets.
  1770 
  1771 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1772 clash with new theory Quotient in Main HOL.
  1773 
  1774 * Moved the SMT binding into the main HOL session, eliminating
  1775 separate HOL-SMT session.
  1776 
  1777 * List membership infix mem operation is only an input abbreviation.
  1778 INCOMPATIBILITY.
  1779 
  1780 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1781 for future developements; former Library/Word.thy is still present in
  1782 the AFP entry RSAPPS.
  1783 
  1784 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1785 longer shadowed.  INCOMPATIBILITY.
  1786 
  1787 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1788 INCOMPATIBILITY.
  1789 
  1790 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1791 INCOMPATIBILITY.
  1792 
  1793 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1794 instead.  INCOMPATIBILITY.
  1795 
  1796 * Dropped several real-specific versions of lemmas about floor and
  1797 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1798 instead.  INCOMPATIBILITY.
  1799 
  1800   floor_number_of_eq         ~> floor_number_of
  1801   le_floor_eq_number_of      ~> number_of_le_floor
  1802   le_floor_eq_zero           ~> zero_le_floor
  1803   le_floor_eq_one            ~> one_le_floor
  1804   floor_less_eq_number_of    ~> floor_less_number_of
  1805   floor_less_eq_zero         ~> floor_less_zero
  1806   floor_less_eq_one          ~> floor_less_one
  1807   less_floor_eq_number_of    ~> number_of_less_floor
  1808   less_floor_eq_zero         ~> zero_less_floor
  1809   less_floor_eq_one          ~> one_less_floor
  1810   floor_le_eq_number_of      ~> floor_le_number_of
  1811   floor_le_eq_zero           ~> floor_le_zero
  1812   floor_le_eq_one            ~> floor_le_one
  1813   floor_subtract_number_of   ~> floor_diff_number_of
  1814   floor_subtract_one         ~> floor_diff_one
  1815   ceiling_number_of_eq       ~> ceiling_number_of
  1816   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1817   ceiling_le_zero_eq         ~> ceiling_le_zero
  1818   ceiling_le_eq_one          ~> ceiling_le_one
  1819   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1820   less_ceiling_eq_zero       ~> zero_less_ceiling
  1821   less_ceiling_eq_one        ~> one_less_ceiling
  1822   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1823   ceiling_less_eq_zero       ~> ceiling_less_zero
  1824   ceiling_less_eq_one        ~> ceiling_less_one
  1825   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1826   le_ceiling_eq_zero         ~> zero_le_ceiling
  1827   le_ceiling_eq_one          ~> one_le_ceiling
  1828   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1829   ceiling_subtract_one       ~> ceiling_diff_one
  1830 
  1831 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1832 application of the various fold combinators on finite sets.
  1833 
  1834 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1835 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1836 implementation.  INCOMPATIBILTY.
  1837 
  1838 * Theory Library/Coinductive_List has been removed -- superseded by
  1839 AFP/thys/Coinductive.
  1840 
  1841 * Theory PReal, including the type "preal" and related operations, has
  1842 been removed.  INCOMPATIBILITY.
  1843 
  1844 * Real: new development using Cauchy Sequences.
  1845 
  1846 * Split off theory "Big_Operators" containing setsum, setprod,
  1847 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1848 
  1849 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1850 "Int" etc.  INCOMPATIBILITY.
  1851 
  1852 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1853 
  1854 * New set of rules "ac_simps" provides combined assoc / commute
  1855 rewrites for all interpretations of the appropriate generic locales.
  1856 
  1857 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1858 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1859 appropriate and more consistent names suitable for name prefixes
  1860 within the HOL theories.  INCOMPATIBILITY.
  1861 
  1862 * Some generic constants have been put to appropriate theories:
  1863   - less_eq, less: Orderings
  1864   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1865   - inverse, divide: Rings
  1866 INCOMPATIBILITY.
  1867 
  1868 * More consistent naming of type classes involving orderings (and
  1869 lattices):
  1870 
  1871     lower_semilattice                   ~> semilattice_inf
  1872     upper_semilattice                   ~> semilattice_sup
  1873 
  1874     dense_linear_order                  ~> dense_linorder
  1875 
  1876     pordered_ab_group_add               ~> ordered_ab_group_add
  1877     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1878     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1879     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1880     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1881     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1882     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1883     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1884     pordered_comm_ring                  ~> ordered_comm_ring
  1885     pordered_comm_semiring              ~> ordered_comm_semiring
  1886     pordered_ring                       ~> ordered_ring
  1887     pordered_ring_abs                   ~> ordered_ring_abs
  1888     pordered_semiring                   ~> ordered_semiring
  1889 
  1890     ordered_ab_group_add                ~> linordered_ab_group_add
  1891     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1892     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1893     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1894     ordered_field                       ~> linordered_field
  1895     ordered_field_no_lb                 ~> linordered_field_no_lb
  1896     ordered_field_no_ub                 ~> linordered_field_no_ub
  1897     ordered_field_dense_linear_order    ~> dense_linordered_field
  1898     ordered_idom                        ~> linordered_idom
  1899     ordered_ring                        ~> linordered_ring
  1900     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1901     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1902     ordered_ring_strict                 ~> linordered_ring_strict
  1903     ordered_semidom                     ~> linordered_semidom
  1904     ordered_semiring                    ~> linordered_semiring
  1905     ordered_semiring_1                  ~> linordered_semiring_1
  1906     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1907     ordered_semiring_strict             ~> linordered_semiring_strict
  1908 
  1909   The following slightly odd type classes have been moved to a
  1910   separate theory Library/Lattice_Algebras:
  1911 
  1912     lordered_ab_group_add               ~> lattice_ab_group_add
  1913     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1914     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1915     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1916     lordered_ring                       ~> lattice_ring
  1917 
  1918 INCOMPATIBILITY.
  1919 
  1920 * Refined field classes:
  1921   - classes division_ring_inverse_zero, field_inverse_zero,
  1922     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1923     subsumes former division_by_zero class;
  1924   - numerous lemmas have been ported from field to division_ring.
  1925 INCOMPATIBILITY.
  1926 
  1927 * Refined algebra theorem collections:
  1928   - dropped theorem group group_simps, use algebra_simps instead;
  1929   - dropped theorem group ring_simps, use field_simps instead;
  1930   - proper theorem collection field_simps subsumes former theorem
  1931     groups field_eq_simps and field_simps;
  1932   - dropped lemma eq_minus_self_iff which is a duplicate for
  1933     equal_neg_zero.
  1934 INCOMPATIBILITY.
  1935 
  1936 * Theory Finite_Set and List: some lemmas have been generalized from
  1937 sets to lattices:
  1938 
  1939   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1940   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1941   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1942   union_Union_fold_union        ~> sup_Sup_fold_sup
  1943   Inter_fold_inter              ~> Inf_fold_inf
  1944   Union_fold_union              ~> Sup_fold_sup
  1945   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1946   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1947   INTER_fold_inter              ~> INFI_fold_inf
  1948   UNION_fold_union              ~> SUPR_fold_sup
  1949 
  1950 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1951 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1952 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1953 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1954 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1955 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1956 
  1957 * Reorganized theory Multiset: swapped notation of pointwise and
  1958 multiset order:
  1959 
  1960   - pointwise ordering is instance of class order with standard syntax
  1961     <= and <;
  1962   - multiset ordering has syntax <=# and <#; partial order properties
  1963     are provided by means of interpretation with prefix
  1964     multiset_order;
  1965   - less duplication, less historical organization of sections,
  1966     conversion from associations lists to multisets, rudimentary code
  1967     generation;
  1968   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1969     if needed.
  1970 
  1971 Renamed:
  1972 
  1973   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1974   multi_count_ext  ~>  multiset_ext
  1975   diff_union_inverse2  ~>  diff_union_cancelR
  1976 
  1977 INCOMPATIBILITY.
  1978 
  1979 * Theory Permutation: replaced local "remove" by List.remove1.
  1980 
  1981 * Code generation: ML and OCaml code is decorated with signatures.
  1982 
  1983 * Theory List: added transpose.
  1984 
  1985 * Library/Nat_Bijection.thy is a collection of bijective functions
  1986 between nat and other types, which supersedes the older libraries
  1987 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1988 
  1989   Constants:
  1990   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1991   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1992   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1993   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1994   Countable.pair_encode           ~> prod_encode
  1995   NatIso.prod2nat                 ~> prod_encode
  1996   NatIso.nat2prod                 ~> prod_decode
  1997   NatIso.sum2nat                  ~> sum_encode
  1998   NatIso.nat2sum                  ~> sum_decode
  1999   NatIso.list2nat                 ~> list_encode
  2000   NatIso.nat2list                 ~> list_decode
  2001   NatIso.set2nat                  ~> set_encode
  2002   NatIso.nat2set                  ~> set_decode
  2003 
  2004   Lemmas:
  2005   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  2006   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  2007   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  2008   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  2009   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  2010   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  2011   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  2012   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  2013   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  2014   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  2015   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  2016   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  2017   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  2018 
  2019 * Sledgehammer:
  2020   - Renamed ATP commands:
  2021     atp_info     ~> sledgehammer running_atps
  2022     atp_kill     ~> sledgehammer kill_atps
  2023     atp_messages ~> sledgehammer messages
  2024     atp_minimize ~> sledgehammer minimize
  2025     print_atps   ~> sledgehammer available_atps
  2026     INCOMPATIBILITY.
  2027   - Added user's manual ("isabelle doc sledgehammer").
  2028   - Added option syntax and "sledgehammer_params" to customize
  2029     Sledgehammer's behavior.  See the manual for details.
  2030   - Modified the Isar proof reconstruction code so that it produces
  2031     direct proofs rather than proofs by contradiction.  (This feature
  2032     is still experimental.)
  2033   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  2034     full-typed mode.
  2035   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  2036 
  2037 * Nitpick:
  2038   - Added and implemented "binary_ints" and "bits" options.
  2039   - Added "std" option and implemented support for nonstandard models.
  2040   - Added and implemented "finitize" option to improve the precision
  2041     of infinite datatypes based on a monotonicity analysis.
  2042   - Added support for quotient types.
  2043   - Added support for "specification" and "ax_specification"
  2044     constructs.
  2045   - Added support for local definitions (for "function" and
  2046     "termination" proofs).
  2047   - Added support for term postprocessors.
  2048   - Optimized "Multiset.multiset" and "FinFun.finfun".
  2049   - Improved efficiency of "destroy_constrs" optimization.
  2050   - Fixed soundness bugs related to "destroy_constrs" optimization and
  2051     record getters.
  2052   - Fixed soundness bug related to higher-order constructors.
  2053   - Fixed soundness bug when "full_descrs" is enabled.
  2054   - Improved precision of set constructs.
  2055   - Added "atoms" option.
  2056   - Added cache to speed up repeated Kodkod invocations on the same
  2057     problems.
  2058   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  2059     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  2060     "SAT4J_Light".  INCOMPATIBILITY.
  2061   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  2062     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  2063   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  2064 
  2065 * Method "induct" now takes instantiations of the form t, where t is not
  2066   a variable, as a shorthand for "x == t", where x is a fresh variable.
  2067   If this is not intended, t has to be enclosed in parentheses.
  2068   By default, the equalities generated by definitional instantiations
  2069   are pre-simplified, which may cause parameters of inductive cases
  2070   to disappear, or may even delete some of the inductive cases.
  2071   Use "induct (no_simp)" instead of "induct" to restore the old
  2072   behaviour. The (no_simp) option is also understood by the "cases"
  2073   and "nominal_induct" methods, which now perform pre-simplification, too.
  2074   INCOMPATIBILITY.
  2075 
  2076 
  2077 *** HOLCF ***
  2078 
  2079 * Variable names in lemmas generated by the domain package have
  2080 changed; the naming scheme is now consistent with the HOL datatype
  2081 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  2082 
  2083 * The domain package no longer defines the function "foo_copy" for
  2084 recursive domain "foo".  The reach lemma is now stated directly in
  2085 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  2086 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  2087 
  2088 * Most definedness lemmas generated by the domain package (previously
  2089 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  2090 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  2091 Proofs that used definedness lemmas as intro rules may break,
  2092 potential INCOMPATIBILITY.
  2093 
  2094 * Induction and casedist rules generated by the domain package now
  2095 declare proper case_names (one called "bottom", and one named for each
  2096 constructor).  INCOMPATIBILITY.
  2097 
  2098 * For mutually-recursive domains, separate "reach" and "take_lemma"
  2099 rules are generated for each domain, INCOMPATIBILITY.
  2100 
  2101   foo_bar.reach       ~> foo.reach  bar.reach
  2102   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  2103 
  2104 * Some lemmas generated by the domain package have been renamed for
  2105 consistency with the datatype package, INCOMPATIBILITY.
  2106 
  2107   foo.ind        ~> foo.induct
  2108   foo.finite_ind ~> foo.finite_induct
  2109   foo.coind      ~> foo.coinduct
  2110   foo.casedist   ~> foo.exhaust
  2111   foo.exhaust    ~> foo.nchotomy
  2112 
  2113 * For consistency with other definition packages, the fixrec package
  2114 now generates qualified theorem names, INCOMPATIBILITY.
  2115 
  2116   foo_simps  ~> foo.simps
  2117   foo_unfold ~> foo.unfold
  2118   foo_induct ~> foo.induct
  2119 
  2120 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  2121 method and internal fixrec proofs now use the default simpset instead.
  2122 INCOMPATIBILITY.
  2123 
  2124 * The "contlub" predicate has been removed.  Proof scripts should use
  2125 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  2126 
  2127 * The "admw" predicate has been removed, INCOMPATIBILITY.
  2128 
  2129 * The constants cpair, cfst, and csnd have been removed in favor of
  2130 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  2131 
  2132 
  2133 *** ML ***
  2134 
  2135 * Antiquotations for basic formal entities:
  2136 
  2137     @{class NAME}         -- type class
  2138     @{class_syntax NAME}  -- syntax representation of the above
  2139 
  2140     @{type_name NAME}     -- logical type
  2141     @{type_abbrev NAME}   -- type abbreviation
  2142     @{nonterminal NAME}   -- type of concrete syntactic category
  2143     @{type_syntax NAME}   -- syntax representation of any of the above
  2144 
  2145     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  2146     @{const_abbrev NAME}  -- abbreviated constant
  2147     @{const_syntax NAME}  -- syntax representation of any of the above
  2148 
  2149 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  2150 syntax constant (cf. 'syntax' command).
  2151 
  2152 * Antiquotation @{make_string} inlines a function to print arbitrary
  2153 values similar to the ML toplevel.  The result is compiler dependent
  2154 and may fall back on "?" in certain situations.
  2155 
  2156 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  2157 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  2158 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  2159 not work with the asynchronous Isar document model.
  2160 
  2161 * Configuration options now admit dynamic default values, depending on
  2162 the context or even global references.
  2163 
  2164 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  2165 uses an efficient external library if available (for Poly/ML).
  2166 
  2167 * Renamed some important ML structures, while keeping the old names
  2168 for some time as aliases within the structure Legacy:
  2169 
  2170   OuterKeyword  ~>  Keyword
  2171   OuterLex      ~>  Token
  2172   OuterParse    ~>  Parse
  2173   OuterSyntax   ~>  Outer_Syntax
  2174   PrintMode     ~>  Print_Mode
  2175   SpecParse     ~>  Parse_Spec
  2176   ThyInfo       ~>  Thy_Info
  2177   ThyLoad       ~>  Thy_Load
  2178   ThyOutput     ~>  Thy_Output
  2179   TypeInfer     ~>  Type_Infer
  2180 
  2181 Note that "open Legacy" simplifies porting of sources, but forgetting
  2182 to remove it again will complicate porting again in the future.
  2183 
  2184 * Most operations that refer to a global context are named
  2185 accordingly, e.g. Simplifier.global_context or
  2186 ProofContext.init_global.  There are some situations where a global
  2187 context actually works, but under normal circumstances one needs to
  2188 pass the proper local context through the code!
  2189 
  2190 * Discontinued old TheoryDataFun with its copy/init operation -- data
  2191 needs to be pure.  Functor Theory_Data_PP retains the traditional
  2192 Pretty.pp argument to merge, which is absent in the standard
  2193 Theory_Data version.
  2194 
  2195 * Sorts.certify_sort and derived "cert" operations for types and terms
  2196 no longer minimize sorts.  Thus certification at the boundary of the
  2197 inference kernel becomes invariant under addition of class relations,
  2198 which is an important monotonicity principle.  Sorts are now minimized
  2199 in the syntax layer only, at the boundary between the end-user and the
  2200 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  2201 explicitly in rare situations.
  2202 
  2203 * Renamed old-style Drule.standard to Drule.export_without_context, to
  2204 emphasize that this is in no way a standard operation.
  2205 INCOMPATIBILITY.
  2206 
  2207 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  2208 usual for resolution.  Rare INCOMPATIBILITY.
  2209 
  2210 * Renamed varify/unvarify operations to varify_global/unvarify_global
  2211 to emphasize that these only work in a global situation (which is
  2212 quite rare).
  2213 
  2214 * Curried take and drop in library.ML; negative length is interpreted
  2215 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  2216 
  2217 * Proof terms: type substitutions on proof constants now use canonical
  2218 order of type variables.  INCOMPATIBILITY for tools working with proof
  2219 terms.
  2220 
  2221 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  2222 may no longer carry premises.  User-level specifications are
  2223 transformed accordingly by Thm.add_axiom/add_def.
  2224 
  2225 
  2226 *** System ***
  2227 
  2228 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  2229 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  2230 proof terms are enabled unconditionally in the new HOL-Proofs image.
  2231 
  2232 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  2233 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  2234 respectively.
  2235 
  2236 * Old lib/scripts/polyml-platform is superseded by the
  2237 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  2238 variant, even on a 64 bit machine.  The following example setting
  2239 prefers 64 bit if available:
  2240 
  2241   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  2242 
  2243 * The preliminary Isabelle/jEdit application demonstrates the emerging
  2244 Isabelle/Scala layer for advanced prover interaction and integration.
  2245 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  2246 component.
  2247 
  2248 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  2249 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  2250 similar to the default assignment of the document preparation system
  2251 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  2252 provides some operations for direct access to the font without asking
  2253 the user for manual installation.
  2254 
  2255 
  2256 
  2257 New in Isabelle2009-1 (December 2009)
  2258 -------------------------------------
  2259 
  2260 *** General ***
  2261 
  2262 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  2263 one backslash should be used, even in ML sources.
  2264 
  2265 
  2266 *** Pure ***
  2267 
  2268 * Locale interpretation propagates mixins along the locale hierarchy.
  2269 The currently only available mixins are the equations used to map
  2270 local definitions to terms of the target domain of an interpretation.
  2271 
  2272 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  2273 loc" to print all interpretations of locale "loc" in the theory.
  2274 Interpretations in proofs are not shown.
  2275 
  2276 * Thoroughly revised locales tutorial.  New section on conditional
  2277 interpretation.
  2278 
  2279 * On instantiation of classes, remaining undefined class parameters
  2280 are formally declared.  INCOMPATIBILITY.
  2281 
  2282 
  2283 *** Document preparation ***
  2284 
  2285 * New generalized style concept for printing terms: @{foo (style) ...}
  2286 instead of @{foo_style style ...}  (old form is still retained for
  2287 backward compatibility).  Styles can be also applied for
  2288 antiquotations prop, term_type and typeof.
  2289 
  2290 
  2291 *** HOL ***
  2292 
  2293 * New proof method "smt" for a combination of first-order logic with
  2294 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  2295 fixed-size bitvectors; there is also basic support for higher-order
  2296 features (esp. lambda abstractions).  It is an incomplete decision
  2297 procedure based on external SMT solvers using the oracle mechanism;
  2298 for the SMT solver Z3, this method is proof-producing.  Certificates
  2299 are provided to avoid calling the external solvers solely for
  2300 re-checking proofs.  Due to a remote SMT service there is no need for
  2301 installing SMT solvers locally.  See src/HOL/SMT.
  2302 
  2303 * New commands to load and prove verification conditions generated by
  2304 the Boogie program verifier or derived systems (e.g. the Verifying C
  2305 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  2306 
  2307 * New counterexample generator tool 'nitpick' based on the Kodkod
  2308 relational model finder.  See src/HOL/Tools/Nitpick and
  2309 src/HOL/Nitpick_Examples.
  2310 
  2311 * New commands 'code_pred' and 'values' to invoke the predicate
  2312 compiler and to enumerate values of inductive predicates.
  2313 
  2314 * A tabled implementation of the reflexive transitive closure.
  2315 
  2316 * New implementation of quickcheck uses generic code generator;
  2317 default generators are provided for all suitable HOL types, records
  2318 and datatypes.  Old quickcheck can be re-activated importing theory
  2319 Library/SML_Quickcheck.
  2320 
  2321 * New testing tool Mirabelle for automated proof tools.  Applies
  2322 several tools and tactics like sledgehammer, metis, or quickcheck, to
  2323 every proof step in a theory.  To be used in batch mode via the
  2324 "mirabelle" utility.
  2325 
  2326 * New proof method "sos" (sum of squares) for nonlinear real
  2327 arithmetic (originally due to John Harison). It requires theory
  2328 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  2329 works well in practice on quantifier-free real arithmetic with +, -,
  2330 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  2331 inequalities between polynomials.  It makes use of external
  2332 semidefinite programming solvers.  Method "sos" generates a
  2333 certificate that can be pasted into the proof thus avoiding the need
  2334 to call an external tool every time the proof is checked.  See
  2335 src/HOL/Library/Sum_Of_Squares.
  2336 
  2337 * New method "linarith" invokes existing linear arithmetic decision
  2338 procedure only.
  2339 
  2340 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  2341 
  2342 * New Sledgehammer option "Full Types" in Proof General settings menu.
  2343 Causes full type information to be output to the ATPs.  This slows
  2344 ATPs down considerably but eliminates a source of unsound "proofs"
  2345 that fail later.
  2346 
  2347 * New method "metisFT": A version of metis that uses full type
  2348 information in order to avoid failures of proof reconstruction.
  2349 
  2350 * New evaluator "approximate" approximates an real valued term using
  2351 the same method as the approximation method.
  2352 
  2353 * Method "approximate" now supports arithmetic expressions as
  2354 boundaries of intervals and implements interval splitting and Taylor
  2355 series expansion.
  2356 
  2357 * ML antiquotation @{code_datatype} inserts definition of a datatype
  2358 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  2359 
  2360 * New theory SupInf of the supremum and infimum operators for sets of
  2361 reals.
  2362 
  2363 * New theory Probability, which contains a development of measure
  2364 theory, eventually leading to Lebesgue integration and probability.
  2365 
  2366 * Extended Multivariate Analysis to include derivation and Brouwer's
  2367 fixpoint theorem.
  2368 
  2369 * Reorganization of number theory, INCOMPATIBILITY:
  2370   - new number theory development for nat and int, in theories Divides
  2371     and GCD as well as in new session Number_Theory
  2372   - some constants and facts now suffixed with _nat and _int
  2373     accordingly
  2374   - former session NumberTheory now named Old_Number_Theory, including
  2375     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  2376   - moved theory Pocklington from src/HOL/Library to
  2377     src/HOL/Old_Number_Theory
  2378 
  2379 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  2380 lcm of finite and infinite sets. It is shown that they form a complete
  2381 lattice.
  2382 
  2383 * Class semiring_div requires superclass no_zero_divisors and proof of
  2384 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  2385 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  2386 generalized to class semiring_div, subsuming former theorems
  2387 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  2388 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  2389 INCOMPATIBILITY.
  2390 
  2391 * Refinements to lattice classes and sets:
  2392   - less default intro/elim rules in locale variant, more default
  2393     intro/elim rules in class variant: more uniformity
  2394   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  2395     le_inf_iff
  2396   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  2397     sup_aci)
  2398   - renamed ACI to inf_sup_aci
  2399   - new class "boolean_algebra"
  2400   - class "complete_lattice" moved to separate theory
  2401     "Complete_Lattice"; corresponding constants (and abbreviations)
  2402     renamed and with authentic syntax:
  2403     Set.Inf ~>    Complete_Lattice.Inf
  2404     Set.Sup ~>    Complete_Lattice.Sup
  2405     Set.INFI ~>   Complete_Lattice.INFI
  2406     Set.SUPR ~>   Complete_Lattice.SUPR
  2407     Set.Inter ~>  Complete_Lattice.Inter
  2408     Set.Union ~>  Complete_Lattice.Union
  2409     Set.INTER ~>  Complete_Lattice.INTER
  2410     Set.UNION ~>  Complete_Lattice.UNION
  2411   - authentic syntax for
  2412     Set.Pow
  2413     Set.image
  2414   - mere abbreviations:
  2415     Set.empty               (for bot)
  2416     Set.UNIV                (for top)
  2417     Set.inter               (for inf, formerly Set.Int)
  2418     Set.union               (for sup, formerly Set.Un)
  2419     Complete_Lattice.Inter  (for Inf)
  2420     Complete_Lattice.Union  (for Sup)
  2421     Complete_Lattice.INTER  (for INFI)
  2422     Complete_Lattice.UNION  (for SUPR)
  2423   - object-logic definitions as far as appropriate
  2424 
  2425 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  2426 Un_subset_iff are explicitly deleted as default simp rules; then also
  2427 their lattice counterparts le_inf_iff and le_sup_iff have to be
  2428 deleted to achieve the desired effect.
  2429 
  2430 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  2431 rules by default any longer; the same applies to min_max.inf_absorb1
  2432 etc.  INCOMPATIBILITY.
  2433 
  2434 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  2435 pred_set_conv by default.  INCOMPATIBILITY.
  2436 
  2437 * Power operations on relations and functions are now one dedicated
  2438 constant "compow" with infix syntax "^^".  Power operation on
  2439 multiplicative monoids retains syntax "^" and is now defined generic
  2440 in class power.  INCOMPATIBILITY.
  2441 
  2442 * Relation composition "R O S" now has a more standard argument order:
  2443 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  2444 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  2445 break, since the O_assoc rule was not rewritten like this.  Fix using
  2446 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  2447 
  2448 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  2449 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  2450 INCOMPATIBILITY.
  2451 
  2452 * Most rules produced by inductive and datatype package have mandatory
  2453 prefixes.  INCOMPATIBILITY.
  2454 
  2455 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  2456 the attribute of the same name.  Each of the theorems in the list
  2457 DERIV_intros assumes composition with an additional function and
  2458 matches a variable to the derivative, which has to be solved by the
  2459 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  2460 of most elementary terms.  Former Maclauren.DERIV_tac and
  2461 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  2462 INCOMPATIBILITY.
  2463 
  2464 * Code generator attributes follow the usual underscore convention:
  2465     code_unfold     replaces    code unfold
  2466     code_post       replaces    code post
  2467     etc.
  2468   INCOMPATIBILITY.
  2469 
  2470 * Renamed methods:
  2471     sizechange -> size_change
  2472     induct_scheme -> induction_schema
  2473   INCOMPATIBILITY.
  2474 
  2475 * Discontinued abbreviation "arbitrary" of constant "undefined".
  2476 INCOMPATIBILITY, use "undefined" directly.
  2477 
  2478 * Renamed theorems:
  2479     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  2480     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  2481     Suc_plus1 -> Suc_eq_plus1
  2482     *anti_sym -> *antisym*
  2483     vector_less_eq_def -> vector_le_def
  2484   INCOMPATIBILITY.
  2485 
  2486 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  2487 INCOMPATIBILITY.
  2488 
  2489 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  2490 INCOMPATIBILITY.
  2491 
  2492 
  2493 *** HOLCF ***
  2494 
  2495 * Theory Representable defines a class "rep" of domains that are
  2496 representable (via an ep-pair) in the universal domain type "udom".
  2497 Instances are provided for all type constructors defined in HOLCF.
  2498 
  2499 * The 'new_domain' command is a purely definitional version of the
  2500 domain package, for representable domains.  Syntax is identical to the
  2501 old domain package.  The 'new_domain' package also supports indirect
  2502 recursion using previously-defined type constructors.  See
  2503 src/HOLCF/ex/New_Domain.thy for examples.
  2504 
  2505 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  2506 on the left-hand side of an equation, and then performs
  2507 simplification.  Rewriting is done using rules declared with the
  2508 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  2509 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  2510 
  2511 * The pattern-match compiler in 'fixrec' can now handle constructors
  2512 with HOL function types.  Pattern-match combinators for the Pair
  2513 constructor are pre-configured.
  2514 
  2515 * The 'fixrec' package now produces better fixed-point induction rules
  2516 for mutually-recursive definitions:  Induction rules have conclusions
  2517 of the form "P foo bar" instead of "P <foo, bar>".
  2518 
  2519 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  2520 been renamed to "below".  The name "below" now replaces "less" in many
  2521 theorem names.  (Legacy theorem names using "less" are still supported
  2522 as well.)
  2523 
  2524 * The 'fixrec' package now supports "bottom patterns".  Bottom
  2525 patterns can be used to generate strictness rules, or to make
  2526 functions more strict (much like the bang-patterns supported by the
  2527 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  2528 examples.
  2529 
  2530 
  2531 *** ML ***
  2532 
  2533 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  2534 errors and run-time exceptions, including detailed source positions.
  2535 
  2536 * Structure Name_Space (formerly NameSpace) now manages uniquely
  2537 identified entries, with some additional information such as source
  2538 position, logical grouping etc.
  2539 
  2540 * Theory and context data is now introduced by the simplified and
  2541 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  2542 to be pure, but the old TheoryDataFun for mutable data (with explicit
  2543 copy operation) is still available for some time.
  2544 
  2545 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  2546 provides a high-level programming interface to synchronized state
  2547 variables with atomic update.  This works via pure function
  2548 application within a critical section -- its runtime should be as
  2549 short as possible; beware of deadlocks if critical code is nested,
  2550 either directly or indirectly via other synchronized variables!
  2551 
  2552 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  2553 wraps raw ML references, explicitly indicating their non-thread-safe
  2554 behaviour.  The Isar toplevel keeps this structure open, to
  2555 accommodate Proof General as well as quick and dirty interactive
  2556 experiments with references.
  2557 
  2558 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  2559 parallel tactical reasoning.
  2560 
  2561 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  2562 are similar to SUBPROOF, but are slightly more flexible: only the
  2563 specified parts of the subgoal are imported into the context, and the
  2564 body tactic may introduce new subgoals and schematic variables.
  2565 
  2566 * Old tactical METAHYPS, which does not observe the proof context, has
  2567 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  2568 or Subgoal.FOCUS etc.
  2569 
  2570 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  2571 functors have their own ML name space there is no point to mark them
  2572 separately.)  Minor INCOMPATIBILITY.
  2573 
  2574 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  2575 
  2576 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  2577 INCOMPATIBILITY.
  2578 
  2579 * Operations of structure Skip_Proof no longer require quick_and_dirty
  2580 mode, which avoids critical setmp.
  2581 
  2582 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  2583 combinators for "args".  INCOMPATIBILITY, need to use simplified
  2584 Attrib/Method.setup introduced in Isabelle2009.
  2585 
  2586 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  2587 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  2588 last resort.  INCOMPATIBILITY.
  2589 
  2590 * Display.pretty_thm now requires a proper context (cf. former
  2591 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  2592 or even Display.pretty_thm_without_context as last resort.
  2593 INCOMPATIBILITY.
  2594 
  2595 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  2596 Syntax.pretty_typ/term directly, preferably with proper context
  2597 instead of global theory.
  2598 
  2599 
  2600 *** System ***
  2601 
  2602 * Further fine tuning of parallel proof checking, scales up to 8 cores
  2603 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  2604 usedir option -q.
  2605 
  2606 * Support for additional "Isabelle components" via etc/components, see
  2607 also the system manual.
  2608 
  2609 * The isabelle makeall tool now operates on all components with
  2610 IsaMakefile, not just hardwired "logics".
  2611 
  2612 * Removed "compress" option from isabelle-process and isabelle usedir;
  2613 this is always enabled.
  2614 
  2615 * Discontinued support for Poly/ML 4.x versions.
  2616 
  2617 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  2618 on a given logic image.  This requires the lighttpd webserver and is
  2619 currently supported on Linux only.
  2620 
  2621 
  2622 
  2623 New in Isabelle2009 (April 2009)
  2624 --------------------------------
  2625 
  2626 *** General ***
  2627 
  2628 * Simplified main Isabelle executables, with less surprises on
  2629 case-insensitive file-systems (such as Mac OS).
  2630 
  2631   - The main Isabelle tool wrapper is now called "isabelle" instead of
  2632     "isatool."
  2633 
  2634   - The former "isabelle" alias for "isabelle-process" has been
  2635     removed (should rarely occur to regular users).
  2636 
  2637   - The former "isabelle-interface" and its alias "Isabelle" have been
  2638     removed (interfaces are now regular Isabelle tools).
  2639 
  2640 Within scripts and make files, the Isabelle environment variables
  2641 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2642 respectively.  (The latter are still available as legacy feature.)
  2643 
  2644 The old isabelle-interface wrapper could react in confusing ways if
  2645 the interface was uninstalled or changed otherwise.  Individual
  2646 interface tool configuration is now more explicit, see also the
  2647 Isabelle system manual.  In particular, Proof General is now available
  2648 via "isabelle emacs".
  2649 
  2650 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2651 purge installed copies of Isabelle executables and re-run "isabelle
  2652 install -p ...", or use symlinks.
  2653 
  2654 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2655 old ~/isabelle, which was slightly non-standard and apt to cause
  2656 surprises on case-insensitive file-systems (such as Mac OS).
  2657 
  2658 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2659 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2660 care is required when using older releases of Isabelle.  Note that
  2661 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2662 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2663 
  2664 * Proofs of fully specified statements are run in parallel on
  2665 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2666 a regular 4-core machine, if the initial heap space is made reasonably
  2667 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2668 
  2669 * The main reference manuals ("isar-ref", "implementation", and
  2670 "system") have been updated and extended.  Formally checked references
  2671 as hyperlinks are now available uniformly.
  2672 
  2673 
  2674 *** Pure ***
  2675 
  2676 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2677 respects.  The most important changes are listed below.  See the
  2678 Tutorial on Locales ("locales" manual) for details.
  2679 
  2680 - In locale expressions, instantiation replaces renaming.  Parameters
  2681 must be declared in a for clause.  To aid compatibility with previous
  2682 parameter inheritance, in locale declarations, parameters that are not
  2683 'touched' (instantiation position "_" or omitted) are implicitly added
  2684 with their syntax at the beginning of the for clause.
  2685 
  2686 - Syntax from abbreviations and definitions in locales is available in
  2687 locale expressions and context elements.  The latter is particularly
  2688 useful in locale declarations.
  2689 
  2690 - More flexible mechanisms to qualify names generated by locale
  2691 expressions.  Qualifiers (prefixes) may be specified in locale
  2692 expressions, and can be marked as mandatory (syntax: "name!:") or
  2693 optional (syntax "name?:").  The default depends for plain "name:"
  2694 depends on the situation where a locale expression is used: in
  2695 commands 'locale' and 'sublocale' prefixes are optional, in
  2696 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2697 implicit qualifiers derived from the parameter names of a locale are
  2698 no longer generated.
  2699 
  2700 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2701 instantiation clause in "interpretation" and "interpret" (square
  2702 brackets) is no longer available.  Use locale expressions.
  2703 
  2704 - When converting proof scripts, mandatory qualifiers in
  2705 'interpretation' and 'interpret' should be retained by default, even
  2706 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2707 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2708 in locale expressions range over a single locale instance only.
  2709 
  2710 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2711 In existing theorem specifications replace the includes element by the
  2712 respective context elements of the included locale, omitting those
  2713 that are already present in the theorem specification.  Multiple
  2714 assume elements of a locale should be replaced by a single one
  2715 involving the locale predicate.  In the proof body, declarations (most
  2716 notably theorems) may be regained by interpreting the respective
  2717 locales in the proof context as required (command "interpret").
  2718 
  2719 If using "includes" in replacement of a target solely because the
  2720 parameter types in the theorem are not as general as in the target,
  2721 consider declaring a new locale with additional type constraints on
  2722 the parameters (context element "constrains").
  2723 
  2724 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2725 
  2726 - Locale interpretation commands no longer attempt to simplify goal.
  2727 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2728 methods intro_locales and unfold_locales to clarify.
  2729 
  2730 - Locale interpretation commands no longer accept interpretation
  2731 attributes.  INCOMPATIBILITY.
  2732 
  2733 * Class declaration: so-called "base sort" must not be given in import
  2734 list any longer, but is inferred from the specification.  Particularly
  2735 in HOL, write
  2736 
  2737     class foo = ...
  2738 
  2739 instead of
  2740 
  2741     class foo = type + ...
  2742 
  2743 * Class target: global versions of theorems stemming do not carry a
  2744 parameter prefix any longer.  INCOMPATIBILITY.
  2745 
  2746 * Class 'instance' command no longer accepts attached definitions.
  2747 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2748 
  2749 * Recovered hiding of consts, which was accidentally broken in
  2750 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2751 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2752 
  2753 * Slightly more coherent Pure syntax, with updated documentation in
  2754 isar-ref manual.  Removed locales meta_term_syntax and
  2755 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2756 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2757 directly in regular applications.
  2758 
  2759 * There is a new syntactic category "float_const" for signed decimal
  2760 fractions (e.g. 123.45 or -123.45).
  2761 
  2762 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2763 interface with 'setup' command instead.
  2764 
  2765 * Command 'local_setup' is similar to 'setup', but operates on a local
  2766 theory context.
  2767 
  2768 * The 'axiomatization' command now only works within a global theory
  2769 context.  INCOMPATIBILITY.
  2770 
  2771 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2772 hypotheses.  Sorts required in the course of reasoning need to be
  2773 covered by the constraints in the initial statement, completed by the
  2774 type instance information of the background theory.  Non-trivial sort
  2775 hypotheses, which rarely occur in practice, may be specified via
  2776 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2777 
  2778   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2779 
  2780 The result contains an implicit sort hypotheses as before --
  2781 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2782 normalization.
  2783 
  2784 * Generalized Isar history, with support for linear undo, direct state
  2785 addressing etc.
  2786 
  2787 * Changed defaults for unify configuration options:
  2788 
  2789   unify_trace_bound = 50 (formerly 25)
  2790   unify_search_bound = 60 (formerly 30)
  2791 
  2792 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2793 
  2794   a) On theory merge, the last set of code equations for a particular
  2795      constant is taken (in accordance with the policy applied by other
  2796      parts of the code generator framework).
  2797 
  2798   b) Code equations stemming from explicit declarations (e.g. code
  2799      attribute) gain priority over default code equations stemming
  2800      from definition, primrec, fun etc.
  2801 
  2802 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2803 
  2804 * Unified theorem tables for both code generators.  Thus [code
  2805 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2806 
  2807 * Command 'find_consts' searches for constants based on type and name
  2808 patterns, e.g.
  2809 
  2810     find_consts "_ => bool"
  2811 
  2812 By default, matching is against subtypes, but it may be restricted to
  2813 the whole type.  Searching by name is possible.  Multiple queries are
  2814 conjunctive and queries may be negated by prefixing them with a
  2815 hyphen:
  2816 
  2817     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2818 
  2819 * New 'find_theorems' criterion "solves" matches theorems that
  2820 directly solve the current goal (modulo higher-order unification).
  2821 
  2822 * Auto solve feature for main theorem statements: whenever a new goal
  2823 is stated, "find_theorems solves" is called; any theorems that could
  2824 solve the lemma directly are listed as part of the goal state.
  2825 Cf. associated options in Proof General Isabelle settings menu,
  2826 enabled by default, with reasonable timeout for pathological cases of
  2827 higher-order unification.
  2828 
  2829 
  2830 *** Document preparation ***
  2831 
  2832 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2833 demanding keyword 'by' and supporting the full method expression
  2834 syntax just like the Isar command 'by'.
  2835 
  2836 
  2837 *** HOL ***
  2838 
  2839 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2840 points Main and Complex_Main remain as before.
  2841 
  2842 * Logic image HOL-Plain provides a minimal HOL with the most important
  2843 tools available (inductive, datatype, primrec, ...).  This facilitates
  2844 experimentation and tool development.  Note that user applications
  2845 (and library theories) should never refer to anything below theory
  2846 Main, as before.
  2847 
  2848 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2849 experimentation due to shorter build times.
  2850 
  2851 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2852 were previously part of former HOL-Complex.  Entry point Hyperreal
  2853 remains valid, but theories formerly using Complex_Main should now use
  2854 new entry point Hypercomplex.
  2855 
  2856 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2857 Posix processes.  Avoids potentially expensive forking of the ML
  2858 process.  New thread-based implementation also works on non-Unix
  2859 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2860 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2861 commands are covered in the isar-ref manual.
  2862 
  2863 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2864 sledgehammer without local ATP installation (Vampire etc.). Other
  2865 provers may be included via suitable ML wrappers, see also
  2866 src/HOL/ATP_Linkup.thy.
  2867 
  2868 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2869 menu.
  2870 
  2871 * The metis method no longer fails because the theorem is too trivial
  2872 (contains the empty clause).
  2873 
  2874 * The metis method now fails in the usual manner, rather than raising
  2875 an exception, if it determines that it cannot prove the theorem.
  2876 
  2877 * Method "coherent" implements a prover for coherent logic (see also
  2878 src/Tools/coherent.ML).
  2879 
  2880 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2881 "undefined" is the right choice to replace "arbitrary", though
  2882 logically there is no difference.  INCOMPATIBILITY.
  2883 
  2884 * Command "value" now integrates different evaluation mechanisms.  The
  2885 result of the first successful evaluation mechanism is printed.  In
  2886 square brackets a particular named evaluation mechanisms may be
  2887 specified (currently, [SML], [code] or [nbe]).  See further
  2888 src/HOL/ex/Eval_Examples.thy.
  2889 
  2890 * Normalization by evaluation now allows non-leftlinear equations.
  2891 Declare with attribute [code nbe].
  2892 
  2893 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2894 as the structured Isar versions "cases" and "induct", cf. the
  2895 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2896 are now presented as a list of individual projections
  2897 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2898 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2899 rare situations a different rule is selected --- notably nested tuple
  2900 elimination instead of former prod.exhaust: use explicit (case_tac t
  2901 rule: prod.exhaust) here.
  2902 
  2903 * Attributes "cases", "induct", "coinduct" support "del" option.
  2904 
  2905 * Removed fact "case_split_thm", which duplicates "case_split".
  2906 
  2907 * The option datatype has been moved to a new theory Option.  Renamed
  2908 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2909 
  2910 * New predicate "strict_mono" classifies strict functions on partial
  2911 orders.  With strict functions on linear orders, reasoning about
  2912 (in)equalities is facilitated by theorems "strict_mono_eq",
  2913 "strict_mono_less_eq" and "strict_mono_less".
  2914 
  2915 * Some set operations are now proper qualified constants with
  2916 authentic syntax.  INCOMPATIBILITY:
  2917 
  2918     op Int ~>   Set.Int
  2919     op Un ~>    Set.Un
  2920     INTER ~>    Set.INTER
  2921     UNION ~>    Set.UNION
  2922     Inter ~>    Set.Inter
  2923     Union ~>    Set.Union
  2924     {} ~>       Set.empty
  2925     UNIV ~>     Set.UNIV
  2926 
  2927 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2928 theory Set.
  2929 
  2930 * Auxiliary class "itself" has disappeared -- classes without any
  2931 parameter are treated as expected by the 'class' command.
  2932 
  2933 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2934 
  2935 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2936 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2937 
  2938 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2939 method "approximation".  It proves formulas on real values by using
  2940 interval arithmetic.  In the formulas are also the transcendental
  2941 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2942 allowed. For examples see
  2943 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2944 
  2945 * Theory "Reflection" now resides in HOL/Library.
  2946 
  2947 * Entry point to Word library now simply named "Word".
  2948 INCOMPATIBILITY.
  2949 
  2950 * Made source layout more coherent with logical distribution
  2951 structure:
  2952 
  2953     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2954     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2955     src/HOL/Library/GCD.thy ~> src/HOL/
  2956     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2957     src/HOL/Library/Parity.thy ~> src/HOL/
  2958     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2959     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2960     src/HOL/Real/Lubs.thy ~> src/HOL/
  2961     src/HOL/Real/PReal.thy ~> src/HOL/
  2962     src/HOL/Real/Rational.thy ~> src/HOL/
  2963     src/HOL/Real/RComplete.thy ~> src/HOL/
  2964     src/HOL/Real/RealDef.thy ~> src/HOL/
  2965     src/HOL/Real/RealPow.thy ~> src/HOL/
  2966     src/HOL/Real/Real.thy ~> src/HOL/
  2967     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2968     src/HOL/Complex/Complex.thy ~> src/HOL/
  2969     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2970     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2971     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2972     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2973     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2974     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2975     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2976     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2977     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2978     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2979     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2980     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2981     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2982     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2983     src/HOL/Real/Float ~> src/HOL/Library/
  2984     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2985     src/HOL/Real/RealVector.thy ~> src/HOL/
  2986 
  2987     src/HOL/arith_data.ML ~> src/HOL/Tools
  2988     src/HOL/hologic.ML ~> src/HOL/Tools
  2989     src/HOL/simpdata.ML ~> src/HOL/Tools
  2990     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2991     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2992     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2993     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2994     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2995     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2996     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2997 
  2998     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2999     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  3000     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  3001     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  3002     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  3003     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  3004 
  3005 * If methods "eval" and "evaluation" encounter a structured proof
  3006 state with !!/==>, only the conclusion is evaluated to True (if
  3007 possible), avoiding strange error messages.
  3008 
  3009 * Method "sizechange" automates termination proofs using (a
  3010 modification of) the size-change principle.  Requires SAT solver.  See
  3011 src/HOL/ex/Termination.thy for examples.
  3012 
  3013 * Simplifier: simproc for let expressions now unfolds if bound
  3014 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  3015 
  3016 * Method "arith": Linear arithmetic now ignores all inequalities when
  3017 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  3018 
  3019 * New attribute "arith" for facts that should always be used
  3020 automatically by arithmetic. It is intended to be used locally in
  3021 proofs, e.g.
  3022 
  3023   assumes [arith]: "x > 0"
  3024 
  3025 Global usage is discouraged because of possible performance impact.
  3026 
  3027 * New classes "top" and "bot" with corresponding operations "top" and
  3028 "bot" in theory Orderings; instantiation of class "complete_lattice"
  3029 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  3030 
  3031 * Changed definition lemma "less_fun_def" in order to provide an
  3032 instance for preorders on functions; use lemma "less_le" instead.
  3033 INCOMPATIBILITY.
  3034 
  3035 * Theory Orderings: class "wellorder" moved here, with explicit
  3036 induction rule "less_induct" as assumption.  For instantiation of
  3037 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  3038 INCOMPATIBILITY.
  3039 
  3040 * Theory Orderings: added class "preorder" as superclass of "order".
  3041 INCOMPATIBILITY: Instantiation proofs for order, linorder
  3042 etc. slightly changed.  Some theorems named order_class.* now named
  3043 preorder_class.*.
  3044 
  3045 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  3046 "diag" to "Id_on".
  3047 
  3048 * Theory Finite_Set: added a new fold combinator of type
  3049 
  3050   ('a => 'b => 'b) => 'b => 'a set => 'b
  3051 
  3052 Occasionally this is more convenient than the old fold combinator
  3053 which is now defined in terms of the new one and renamed to
  3054 fold_image.
  3055 
  3056 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  3057 and "ring_simps" have been replaced by "algebra_simps" (which can be
  3058 extended with further lemmas!).  At the moment both still exist but
  3059 the former will disappear at some point.
  3060 
  3061 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  3062 class recpower.  Type-specific simp rules for various recpower types
  3063 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  3064 
  3065 rat_power_0    -> power_0
  3066 rat_power_Suc  -> power_Suc
  3067 realpow_0      -> power_0
  3068 realpow_Suc    -> power_Suc
  3069 complexpow_0   -> power_0
  3070 complexpow_Suc -> power_Suc
  3071 power_poly_0   -> power_0
  3072 power_poly_Suc -> power_Suc
  3073 
  3074 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  3075 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  3076 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  3077 of lemmas from Divides has been generalized from nat to class
  3078 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  3079 renames resulting from duplicate elimination:
  3080 
  3081     dvd_def_mod ~>          dvd_eq_mod_eq_0
  3082     zero_dvd_iff ~>         dvd_0_left_iff
  3083     dvd_0 ~>                dvd_0_right
  3084     DIVISION_BY_ZERO_DIV ~> div_by_0
  3085     DIVISION_BY_ZERO_MOD ~> mod_by_0
  3086     mult_div ~>             div_mult_self2_is_id
  3087     mult_mod ~>             mod_mult_self2_is_0
  3088 
  3089 * Theory IntDiv: removed many lemmas that are instances of class-based
  3090 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  3091 rename old lemmas as follows:
  3092 
  3093 dvd_diff               -> nat_dvd_diff
  3094 dvd_zminus_iff         -> dvd_minus_iff
  3095 mod_add1_eq            -> mod_add_eq
  3096 mod_mult1_eq           -> mod_mult_right_eq
  3097 mod_mult1_eq'          -> mod_mult_left_eq
  3098 mod_mult_distrib_mod   -> mod_mult_eq
  3099 nat_mod_add_left_eq    -> mod_add_left_eq
  3100 nat_mod_add_right_eq   -> mod_add_right_eq
  3101 nat_mod_div_trivial    -> mod_div_trivial
  3102 nat_mod_mod_trivial    -> mod_mod_trivial
  3103 zdiv_zadd_self1        -> div_add_self1
  3104 zdiv_zadd_self2        -> div_add_self2
  3105 zdiv_zmult_self1       -> div_mult_self2_is_id
  3106 zdiv_zmult_self2       -> div_mult_self1_is_id
  3107 zdvd_triv_left         -> dvd_triv_left
  3108 zdvd_triv_right        -> dvd_triv_right
  3109 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  3110 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  3111 zmod_zadd_left_eq      -> mod_add_left_eq
  3112 zmod_zadd_right_eq     -> mod_add_right_eq
  3113 zmod_zadd_self1        -> mod_add_self1
  3114 zmod_zadd_self2        -> mod_add_self2
  3115 zmod_zadd1_eq          -> mod_add_eq
  3116 zmod_zdiff1_eq         -> mod_diff_eq
  3117 zmod_zdvd_zmod         -> mod_mod_cancel
  3118 zmod_zmod_cancel       -> mod_mod_cancel
  3119 zmod_zmult_self1       -> mod_mult_self2_is_0
  3120 zmod_zmult_self2       -> mod_mult_self1_is_0
  3121 zmod_1                 -> mod_by_1
  3122 zdiv_1                 -> div_by_1
  3123 zdvd_abs1              -> abs_dvd_iff
  3124 zdvd_abs2              -> dvd_abs_iff
  3125 zdvd_refl              -> dvd_refl
  3126 zdvd_trans             -> dvd_trans
  3127 zdvd_zadd              -> dvd_add
  3128 zdvd_zdiff             -> dvd_diff
  3129 zdvd_zminus_iff        -> dvd_minus_iff
  3130 zdvd_zminus2_iff       -> minus_dvd_iff
  3131 zdvd_zmultD            -> dvd_mult_right
  3132 zdvd_zmultD2           -> dvd_mult_left
  3133 zdvd_zmult_mono        -> mult_dvd_mono
  3134 zdvd_0_right           -> dvd_0_right
  3135 zdvd_0_left            -> dvd_0_left_iff
  3136 zdvd_1_left            -> one_dvd
  3137 zminus_dvd_iff         -> minus_dvd_iff
  3138 
  3139 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  3140 
  3141 * The real numbers offer decimal input syntax: 12.34 is translated
  3142 into 1234/10^2. This translation is not reversed upon output.
  3143 
  3144 * Theory Library/Polynomial defines an abstract type 'a poly of
  3145 univariate polynomials with coefficients of type 'a.  In addition to
  3146 the standard ring operations, it also supports div and mod.  Code
  3147 generation is also supported, using list-style constructors.
  3148 
  3149 * Theory Library/Inner_Product defines a class of real_inner for real
  3150 inner product spaces, with an overloaded operation inner :: 'a => 'a
  3151 => real.  Class real_inner is a subclass of real_normed_vector from
  3152 theory RealVector.
  3153 
  3154 * Theory Library/Product_Vector provides instances for the product
  3155 type 'a * 'b of several classes from RealVector and Inner_Product.
  3156 Definitions of addition, subtraction, scalar multiplication, norms,
  3157 and inner products are included.
  3158 
  3159 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  3160 addition to the field operations, numerals and case syntax are also
  3161 supported.
  3162 
  3163 * Theory Library/Diagonalize provides constructive version of Cantor's
  3164 first diagonalization argument.
  3165 
  3166 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  3167 zlcm (for int); carried together from various gcd/lcm developements in
  3168 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  3169 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  3170 may recover tupled syntax as follows:
  3171 
  3172     hide (open) const gcd
  3173     abbreviation gcd where
  3174       "gcd == (%(a, b). GCD.gcd a b)"
  3175     notation (output)
  3176       GCD.gcd ("gcd '(_, _')")
  3177 
  3178 The same works for lcm, zgcd, zlcm.
  3179 
  3180 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  3181 instantiations for algebraic structures.  Removed some duplicate
  3182 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  3183 
  3184 * ML antiquotation @{code} takes a constant as argument and generates
  3185 corresponding code in background and inserts name of the corresponding
  3186 resulting ML value/function/datatype constructor binding in place.
  3187 All occurrences of @{code} with a single ML block are generated
  3188 simultaneously.  Provides a generic and safe interface for
  3189 instrumentalizing code generation.  See
  3190 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  3191 In future you ought to refrain from ad-hoc compiling generated SML
  3192 code on the ML toplevel.  Note that (for technical reasons) @{code}
  3193 cannot refer to constants for which user-defined serializations are
  3194 set.  Refer to the corresponding ML counterpart directly in that
  3195 cases.
  3196 
  3197 * Command 'rep_datatype': instead of theorem names the command now
  3198 takes a list of terms denoting the constructors of the type to be
  3199 represented as datatype.  The characteristic theorems have to be
  3200 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  3201 have disappeared in favour of existing ones:
  3202 
  3203     unit_induct                 ~> unit.induct
  3204     prod_induct                 ~> prod.induct
  3205     sum_induct                  ~> sum.induct
  3206     Suc_Suc_eq                  ~> nat.inject
  3207     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  3208 
  3209 
  3210 *** HOL-Algebra ***
  3211 
  3212 * New locales for orders and lattices where the equivalence relation
  3213 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  3214 locales use a record structure with field eq for the equivalence.
  3215 
  3216 * New theory of factorial domains.
  3217 
  3218 * Units_l_inv and Units_r_inv are now simp rules by default.
  3219 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  3220 and/or r_inv will now also require deletion of these lemmas.
  3221 
  3222 * Renamed the following theorems, INCOMPATIBILITY:
  3223 
  3224 UpperD ~> Upper_memD
  3225 LowerD ~> Lower_memD
  3226 least_carrier ~> least_closed
  3227 greatest_carrier ~> greatest_closed
  3228 greatest_Lower_above ~> greatest_Lower_below
  3229 one_zero ~> carrier_one_zero
  3230 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  3231 
  3232 
  3233 *** HOL-Nominal ***
  3234 
  3235 * Nominal datatypes can now contain type-variables.
  3236 
  3237 * Commands 'nominal_inductive' and 'equivariance' work with local
  3238 theory targets.
  3239 
  3240 * Nominal primrec can now works with local theory targets and its
  3241 specification syntax now conforms to the general format as seen in
  3242 'inductive' etc.
  3243 
  3244 * Method "perm_simp" honours the standard simplifier attributes
  3245 (no_asm), (no_asm_use) etc.
  3246 
  3247 * The new predicate #* is defined like freshness, except that on the
  3248 left hand side can be a set or list of atoms.
  3249 
  3250 * Experimental command 'nominal_inductive2' derives strong induction
  3251 principles for inductive definitions.  In contrast to
  3252 'nominal_inductive', which can only deal with a fixed number of
  3253 binders, it can deal with arbitrary expressions standing for sets of
  3254 atoms to be avoided.  The only inductive definition we have at the
  3255 moment that needs this generalisation is the typing rule for Lets in
  3256 the algorithm W:
  3257 
  3258  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  3259  -----------------------------------------------------------------
  3260          Gamma |- Let x be t1 in t2 : T2
  3261 
  3262 In this rule one wants to avoid all the binders that are introduced by
  3263 "close Gamma T1".  We are looking for other examples where this
  3264 feature might be useful.  Please let us know.
  3265 
  3266 
  3267 *** HOLCF ***
  3268 
  3269 * Reimplemented the simplification procedure for proving continuity
  3270 subgoals.  The new simproc is extensible; users can declare additional
  3271 continuity introduction rules with the attribute [cont2cont].
  3272 
  3273 * The continuity simproc now uses a different introduction rule for
  3274 solving continuity subgoals on terms with lambda abstractions.  In
  3275 some rare cases the new simproc may fail to solve subgoals that the
  3276 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  3277 Potential INCOMPATIBILITY.
  3278 
  3279 * Command 'fixrec': specification syntax now conforms to the general
  3280 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  3281 examples.  INCOMPATIBILITY.
  3282 
  3283 
  3284 *** ZF ***
  3285 
  3286 * Proof of Zorn's Lemma for partial orders.
  3287 
  3288 
  3289 *** ML ***
  3290 
  3291 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  3292 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  3293 depends on multithreading, so timouts will not work before Poly/ML
  3294 5.2.1!
  3295 
  3296 * High-level support for concurrent ML programming, see
  3297 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  3298 particularly convenient to organize independent functional
  3299 computations.  The concept of "synchronized variables" provides a
  3300 higher-order interface for components with shared state, avoiding the
  3301 delicate details of mutexes and condition variables.  (Requires
  3302 Poly/ML 5.2.1 or later.)
  3303 
  3304 * ML bindings produced via Isar commands are stored within the Isar
  3305 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  3306 become thread-safe and work with undo as expected (concerning
  3307 top-level bindings, not side-effects on global references).
  3308 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  3309 compiler at runtime; really global bindings need to be given outside a
  3310 theory.  (Requires Poly/ML 5.2 or later.)
  3311 
  3312 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  3313 context.  Top-level ML bindings are stored within the proof context in
  3314 a purely sequential fashion, disregarding the nested proof structure.
  3315 ML bindings introduced by 'ML_prf' are discarded at the end of the
  3316 proof.  (Requires Poly/ML 5.2 or later.)
  3317 
  3318 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  3319 and Method.setup, as well as Isar commands 'attribute_setup' and
  3320 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  3321 existing code accordingly, or use plain 'setup' together with old
  3322 Method.add_method.
  3323 
  3324 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  3325 to 'a -> thm, while results are always tagged with an authentic oracle
  3326 name.  The Isar command 'oracle' is now polymorphic, no argument type
  3327 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  3328 accordingly.  Note that extra performance may be gained by producing
  3329 the cterm carefully, avoiding slow Thm.cterm_of.
  3330 
  3331 * Simplified interface for defining document antiquotations via
  3332 ThyOutput.antiquotation, ThyOutput.output, and optionally
  3333 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  3334 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  3335 examples.
  3336 
  3337 * More systematic treatment of long names, abstract name bindings, and
  3338 name space operations.  Basic operations on qualified names have been
  3339 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  3340 Long_Name.append.  Old type bstring has been mostly replaced by
  3341 abstract type binding (see structure Binding), which supports precise
  3342 qualification by packages and local theory targets, as well as proper
  3343 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  3344 bstring values into Binding.name, or better pass through abstract
  3345 bindings everywhere.  See further src/Pure/General/long_name.ML,
  3346 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  3347 
  3348 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  3349 LocalTheory.note etc.) now refer to the *full* internal name, not the
  3350 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  3351 
  3352 * Disposed old type and term read functions (Sign.read_def_typ,
  3353 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  3354 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  3355 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  3356 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  3357 resort for legacy applications.
  3358 
  3359 * Disposed old declarations, tactics, tactic combinators that refer to
  3360 the simpset or claset of an implicit theory (such as Addsimps,
  3361 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  3362 embedded ML text, or local_simpset_of with a proper context passed as
  3363 explicit runtime argument.
  3364 
  3365 * Rules and tactics that read instantiations (read_instantiate,
  3366 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  3367 context, which is required for parsing and type-checking.  Moreover,
  3368 the variables are specified as plain indexnames, not string encodings
  3369 thereof.  INCOMPATIBILITY.
  3370 
  3371 * Generic Toplevel.add_hook interface allows to analyze the result of
  3372 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  3373 for theorem dependency output of transactions resulting in a new
  3374 theory state.
  3375 
  3376 * ML antiquotations: block-structured compilation context indicated by
  3377 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  3378 
  3379   @{binding name}                         - basic name binding
  3380   @{let ?pat = term}                      - term abbreviation (HO matching)
  3381   @{note name = fact}                     - fact abbreviation
  3382   @{thm fact}                             - singleton fact (with attributes)
  3383   @{thms fact}                            - general fact (with attributes)
  3384   @{lemma prop by method}                 - singleton goal
  3385   @{lemma prop by meth1 meth2}            - singleton goal
  3386   @{lemma prop1 ... propN by method}      - general goal
  3387   @{lemma prop1 ... propN by meth1 meth2} - general goal
  3388   @{lemma (open) ...}                     - open derivation
  3389 
  3390 
  3391 *** System ***
  3392 
  3393 * The Isabelle "emacs" tool provides a specific interface to invoke
  3394 Proof General / Emacs, with more explicit failure if that is not
  3395 installed (the old isabelle-interface script silently falls back on
  3396 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  3397 installation location of the Proof General distribution.
  3398 
  3399 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  3400 the Isabelle process into a JVM/Scala application.  See
  3401 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  3402 process wrapper has been discontinued.)
  3403 
  3404 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  3405 
  3406 * Various status messages (with exact source position information) are
  3407 emitted, if proper markup print mode is enabled.  This allows
  3408 user-interface components to provide detailed feedback on internal
  3409 prover operations.
  3410 
  3411 
  3412 
  3413 New in Isabelle2008 (June 2008)
  3414 -------------------------------
  3415 
  3416 *** General ***
  3417 
  3418 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  3419 and updated, with formally checked references as hyperlinks.
  3420 
  3421 * Theory loader: use_thy (and similar operations) no longer set the
  3422 implicit ML context, which was occasionally hard to predict and in
  3423 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  3424 provides a proper context already.
  3425 
  3426 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3427 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  3428 'use' within a theory file will do the job.
  3429 
  3430 * Name space merge now observes canonical order, i.e. the second space
  3431 is inserted into the first one, while existing entries in the first
  3432 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  3433 swap theory imports.
  3434 
  3435 * Syntax: symbol \<chi> is now considered a letter.  Potential
  3436 INCOMPATIBILITY in identifier syntax etc.
  3437 
  3438 * Outer syntax: string tokens no longer admit escaped white space,
  3439 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  3440 white space without escapes.
  3441 
  3442 * Outer syntax: string tokens may contain arbitrary character codes
  3443 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  3444 "foo_bar".
  3445 
  3446 
  3447 *** Pure ***
  3448 
  3449 * Context-dependent token translations.  Default setup reverts locally
  3450 fixed variables, and adds hilite markup for undeclared frees.
  3451 
  3452 * Unused theorems can be found using the new command 'unused_thms'.
  3453 There are three ways of invoking it:
  3454 
  3455 (1) unused_thms
  3456      Only finds unused theorems in the current theory.
  3457 
  3458 (2) unused_thms thy_1 ... thy_n -
  3459      Finds unused theorems in the current theory and all of its ancestors,
  3460      excluding the theories thy_1 ... thy_n and all of their ancestors.
  3461 
  3462 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  3463      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  3464      their ancestors, excluding the theories thy_1 ... thy_n and all of
  3465      their ancestors.
  3466 
  3467 In order to increase the readability of the list produced by
  3468 unused_thms, theorems that have been created by a particular instance
  3469 of a theory command such as 'inductive' or 'function' are considered
  3470 to belong to the same "group", meaning that if at least one theorem in
  3471 this group is used, the other theorems in the same group are no longer
  3472 reported as unused.  Moreover, if all theorems in the group are
  3473 unused, only one theorem in the group is displayed.
  3474 
  3475 Note that proof objects have to be switched on in order for
  3476 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  3477 usually the case when using Proof General with the default settings).
  3478 
  3479 * Authentic naming of facts disallows ad-hoc overwriting of previous
  3480 theorems within the same name space.  INCOMPATIBILITY, need to remove
  3481 duplicate fact bindings, or even accidental fact duplications.  Note
  3482 that tools may maintain dynamically scoped facts systematically, using
  3483 PureThy.add_thms_dynamic.
  3484 
  3485 * Command 'hide' now allows to hide from "fact" name space as well.
  3486 
  3487 * Eliminated destructive theorem database, simpset, claset, and
  3488 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  3489 update of theories within ML code.
  3490 
  3491 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  3492 INCOMPATIBILITY, object-logics depending on former Pure require
  3493 additional setup PureThy.old_appl_syntax_setup; object-logics
  3494 depending on former CPure need to refer to Pure.
  3495 
  3496 * Commands 'use' and 'ML' are now purely functional, operating on
  3497 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  3498 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  3499 INCOMPATIBILITY.
  3500 
  3501 * Command 'setup': discontinued implicit version with ML reference.
  3502 
  3503 * Instantiation target allows for simultaneous specification of class
  3504 instance operations together with an instantiation proof.
  3505 Type-checking phase allows to refer to class operations uniformly.
  3506 See src/HOL/Complex/Complex.thy for an Isar example and
  3507 src/HOL/Library/Eval.thy for an ML example.
  3508 
  3509 * Indexing of literal facts: be more serious about including only
  3510 facts from the visible specification/proof context, but not the
  3511 background context (locale etc.).  Affects `prop` notation and method
  3512 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  3513 situations.
  3514 
  3515 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  3516 "(open)" option, which used to expose internal bound variables to the
  3517 proof text.
  3518 
  3519 * Isar statements: removed obsolete case "rule_context".
  3520 INCOMPATIBILITY, better use explicit fixes/assumes.
  3521 
  3522 * Locale proofs: default proof step now includes 'unfold_locales';
  3523 hence 'proof' without argument may be used to unfold locale
  3524 predicates.
  3525 
  3526 
  3527 *** Document preparation ***
  3528 
  3529 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  3530 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  3531 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  3532 spot); renamed link color from "darkblue" to "linkcolor" (default
  3533 value unchanged, can be redefined via \definecolor); no longer sets
  3534 "a4paper" option (unnecessary or even intrusive).
  3535 
  3536 * Antiquotation @{lemma A method} proves proposition A by the given
  3537 method (either a method name or a method name plus (optional) method
  3538 arguments in parentheses) and prints A just like @{prop A}.
  3539 
  3540 
  3541 *** HOL ***
  3542 
  3543 * New primrec package.  Specification syntax conforms in style to
  3544 definition/function/....  No separate induction rule is provided.  The
  3545 "primrec" command distinguishes old-style and new-style specifications
  3546 by syntax.  The former primrec package is now named OldPrimrecPackage.
  3547 When adjusting theories, beware: constants stemming from new-style
  3548 primrec specifications have authentic syntax.
  3549 
  3550 * Metis prover is now an order of magnitude faster, and also works
  3551 with multithreading.
  3552 
  3553 * Metis: the maximum number of clauses that can be produced from a
  3554 theorem is now given by the attribute max_clauses.  Theorems that
  3555 exceed this number are ignored, with a warning printed.
  3556 
  3557 * Sledgehammer no longer produces structured proofs by default. To
  3558 enable, declare [[sledgehammer_full = true]].  Attributes
  3559 reconstruction_modulus, reconstruction_sorts renamed
  3560 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  3561 
  3562 * Method "induct_scheme" derives user-specified induction rules
  3563 from well-founded induction and completeness of patterns. This factors
  3564 out some operations that are done internally by the function package
  3565 and makes them available separately.  See
  3566 src/HOL/ex/Induction_Scheme.thy for examples.
  3567 
  3568 * More flexible generation of measure functions for termination
  3569 proofs: Measure functions can be declared by proving a rule of the
  3570 form "is_measure f" and giving it the [measure_function] attribute.
  3571 The "is_measure" predicate is logically meaningless (always true), and
  3572 just guides the heuristic.  To find suitable measure functions, the
  3573 termination prover sets up the goal "is_measure ?f" of the appropriate
  3574 type and generates all solutions by prolog-style backwards proof using
  3575 the declared rules.
  3576 
  3577 This setup also deals with rules like 
  3578 
  3579   "is_measure f ==> is_measure (list_size f)"
  3580 
  3581 which accommodates nested datatypes that recurse through lists.
  3582 Similar rules are predeclared for products and option types.
  3583 
  3584 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  3585 
  3586   INCOMPATIBILITIES:
  3587 
  3588   - Definitions of overloaded constants on sets have to be replaced by
  3589     definitions on => and bool.
  3590 
  3591   - Some definitions of overloaded operators on sets can now be proved
  3592     using the definitions of the operators on => and bool.  Therefore,
  3593     the following theorems have been renamed:
  3594 
  3595       subset_def   -> subset_eq
  3596       psubset_def  -> psubset_eq
  3597       set_diff_def -> set_diff_eq
  3598       Compl_def    -> Compl_eq
  3599       Sup_set_def  -> Sup_set_eq
  3600       Inf_set_def  -> Inf_set_eq
  3601       sup_set_def  -> sup_set_eq
  3602       inf_set_def  -> inf_set_eq
  3603 
  3604   - Due to the incompleteness of the HO unification algorithm, some
  3605     rules such as subst may require manual instantiation, if some of
  3606     the unknowns in the rule is a set.
  3607 
  3608   - Higher order unification and forward proofs:
  3609     The proof pattern
  3610 
  3611       have "P (S::'a set)" <...>
  3612       then have "EX S. P S" ..
  3613 
  3614     no longer works (due to the incompleteness of the HO unification
  3615     algorithm) and must be replaced by the pattern
  3616 
  3617       have "EX S. P S"
  3618       proof
  3619         show "P S" <...>
  3620       qed
  3621 
  3622   - Calculational reasoning with subst (or similar rules):
  3623     The proof pattern
  3624 
  3625       have "P (S::'a set)" <...>
  3626       also have "S = T" <...>
  3627       finally have "P T" .
  3628 
  3629     no longer works (for similar reasons as the previous example) and
  3630     must be replaced by something like
  3631 
  3632       have "P (S::'a set)" <...>
  3633       moreover have "S = T" <...>
  3634       ultimately have "P T" by simp
  3635 
  3636   - Tactics or packages written in ML code:
  3637     Code performing pattern matching on types via
  3638 
  3639       Type ("set", [T]) => ...
  3640 
  3641     must be rewritten. Moreover, functions like strip_type or
  3642     binder_types no longer return the right value when applied to a
  3643     type of the form
  3644 
  3645       T1 => ... => Tn => U => bool
  3646 
  3647     rather than
  3648 
  3649       T1 => ... => Tn => U set
  3650 
  3651 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3652 Wellfounded_Relations to theory Wellfounded.
  3653 
  3654 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3655 
  3656 * Class finite no longer treats UNIV as class parameter.  Use class
  3657 enum from theory Library/Enum instead to achieve a similar effect.
  3658 INCOMPATIBILITY.
  3659 
  3660 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3661 and "Cons".  INCOMPATIBILITY.
  3662 
  3663 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3664 Potential INCOMPATIBILITY.
  3665 
  3666 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3667 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3668 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3669 
  3670 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3671 the same name in theory Orderings:
  3672 
  3673   less_trans
  3674   less_linear
  3675   le_imp_less_or_eq
  3676   le_less_trans
  3677   less_le_trans
  3678   less_not_sym
  3679   less_asym
  3680 
  3681 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3682 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3683 and different variable names.
  3684 
  3685 * Library/Option_ord.thy: Canonical order on option type.
  3686 
  3687 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3688 finite maps.
  3689 
  3690 * Library/Countable.thy: Type class for countable types.
  3691 
  3692 * Theory Int: The representation of numerals has changed.  The infix
  3693 operator BIT and the bit datatype with constructors B0 and B1 have
  3694 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3695 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3696 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3697 accordingly.
  3698 
  3699 * Theory Nat: definition of <= and < on natural numbers no longer
  3700 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3701 le_def and less_def have disappeared.  Consider lemmas not_less
  3702 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3703 
  3704 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3705 (whose purpose mainly is for various fold_set functionals) have been
  3706 abandoned in favor of the existing algebraic classes
  3707 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3708 lower_semilattice (resp. upper_semilattice) and linorder.
  3709 INCOMPATIBILITY.
  3710 
  3711 * Theory Transitive_Closure: induct and cases rules now declare proper
  3712 case_names ("base" and "step").  INCOMPATIBILITY.
  3713 
  3714 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3715 lattices.  The form set-specific version is available as
  3716 Inductive.lfp_ordinal_induct_set.
  3717 
  3718 * Renamed theorems "power.simps" to "power_int.simps".
  3719 INCOMPATIBILITY.
  3720 
  3721 * Class semiring_div provides basic abstract properties of semirings
  3722 with division and modulo operations.  Subsumes former class dvd_mod.
  3723 
  3724 * Merged theories IntDef, Numeral and IntArith into unified theory
  3725 Int.  INCOMPATIBILITY.
  3726 
  3727 * Theory Library/Code_Index: type "index" now represents natural
  3728 numbers rather than integers.  INCOMPATIBILITY.
  3729 
  3730 * New class "uminus" with operation "uminus" (split of from class
  3731 "minus" which now only has operation "minus", binary).
  3732 INCOMPATIBILITY.
  3733 
  3734 * Constants "card", "internal_split", "option_map" now with authentic
  3735 syntax.  INCOMPATIBILITY.
  3736 
  3737 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3738 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3739 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3740 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3741 Sup_set_def, le_def, less_def, option_map_def now with object
  3742 equality.  INCOMPATIBILITY.
  3743 
  3744 * Records. Removed K_record, and replaced it by pure lambda term
  3745 %x. c. The simplifier setup is now more robust against eta expansion.
  3746 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3747 
  3748 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3749 
  3750 * Library/ListVector: new theory of arithmetic vector operations.
  3751 
  3752 * Library/Order_Relation: new theory of various orderings as sets of
  3753 pairs.  Defines preorders, partial orders, linear orders and
  3754 well-orders on sets and on types.
  3755 
  3756 
  3757 *** ZF ***
  3758 
  3759 * Renamed some theories to allow to loading both ZF and HOL in the
  3760 same session:
  3761 
  3762   Datatype  -> Datatype_ZF
  3763   Inductive -> Inductive_ZF
  3764   Int       -> Int_ZF
  3765   IntDiv    -> IntDiv_ZF
  3766   Nat       -> Nat_ZF
  3767   List      -> List_ZF
  3768   Main      -> Main_ZF
  3769 
  3770 INCOMPATIBILITY: ZF theories that import individual theories below
  3771 Main might need to be adapted.  Regular theory Main is still
  3772 available, as trivial extension of Main_ZF.
  3773 
  3774 
  3775 *** ML ***
  3776 
  3777 * ML within Isar: antiquotation @{const name} or @{const
  3778 name(typargs)} produces statically-checked Const term.
  3779 
  3780 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3781 (of the same name).  Removed obsolete print command.
  3782 
  3783 * Removed obsolete "use_legacy_bindings" function.
  3784 
  3785 * The ``print mode'' is now a thread-local value derived from a global
  3786 template (the former print_mode reference), thus access becomes
  3787 non-critical.  The global print_mode reference is for session
  3788 management only; user-code should use print_mode_value,
  3789 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3790 
  3791 * Functions system/system_out provide a robust way to invoke external
  3792 shell commands, with propagation of interrupts (requires Poly/ML
  3793 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3794 
  3795 
  3796 *** System ***
  3797 
  3798 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3799 in accordance with Proof General 3.7, which prefers GNU emacs.
  3800 
  3801 * isatool tty runs Isabelle process with plain tty interaction;
  3802 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3803 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3804 
  3805 * isatool browser now works with Cygwin as well, using general
  3806 "javapath" function defined in Isabelle process environment.
  3807 
  3808 * YXML notation provides a simple and efficient alternative to
  3809 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3810 isatool yxml as described in the Isabelle system manual.
  3811 
  3812 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3813 provides general wrapper for managing an Isabelle process in a robust
  3814 fashion, with ``cooked'' output from stdin/stderr.
  3815 
  3816 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3817 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3818 
  3819 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3820 way of changing the user's settings is via
  3821 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3822 script.
  3823 
  3824 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3825 cores of the underlying machine, which is a good starting point for
  3826 optimal performance tuning.  The corresponding usedir option -M allows
  3827 "max" as an alias for "0".  WARNING: does not work on certain versions
  3828 of Mac OS (with Poly/ML 5.1).
  3829 
  3830 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3831 adverse effect of Isabelle flooding interactive front-ends (notably
  3832 ProofGeneral / XEmacs).
  3833 
  3834 
  3835 
  3836 New in Isabelle2007 (November 2007)
  3837 -----------------------------------
  3838 
  3839 *** General ***
  3840 
  3841 * More uniform information about legacy features, notably a
  3842 warning/error of "Legacy feature: ...", depending on the state of the
  3843 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3844 legacy features will disappear eventually.
  3845 
  3846 * Theory syntax: the header format ``theory A = B + C:'' has been
  3847 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3848 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3849 
  3850 * Theory syntax: the old non-Isar theory file format has been
  3851 discontinued altogether.  Note that ML proof scripts may still be used
  3852 with Isar theories; migration is usually quite simple with the ML
  3853 function use_legacy_bindings.  INCOMPATIBILITY.
  3854 
  3855 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3856 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3857 quotes.
  3858 
  3859 * Theory loader: be more serious about observing the static theory
  3860 header specifications (including optional directories), but not the
  3861 accidental file locations of previously successful loads.  The strict
  3862 update policy of former update_thy is now already performed by
  3863 use_thy, so the former has been removed; use_thys updates several
  3864 theories simultaneously, just as 'imports' within a theory header
  3865 specification, but without merging the results.  Potential
  3866 INCOMPATIBILITY: may need to refine theory headers and commands
  3867 ROOT.ML which depend on load order.
  3868 
  3869 * Theory loader: optional support for content-based file
  3870 identification, instead of the traditional scheme of full physical
  3871 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3872 (cf. the system manual).  The new scheme allows to work with
  3873 non-finished theories in persistent session images, such that source
  3874 files may be moved later on without requiring reloads.
  3875 
  3876 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3877 file (with the same base name as the theory) are considered a legacy
  3878 feature, which will disappear eventually. Even now, the theory loader
  3879 no longer maintains dependencies on such files.
  3880 
  3881 * Syntax: the scope for resolving ambiguities via type-inference is
  3882 now limited to individual terms, instead of whole simultaneous
  3883 specifications as before. This greatly reduces the complexity of the
  3884 syntax module and improves flexibility by separating parsing and
  3885 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3886 'fixes' etc.) are required in rare situations.
  3887 
  3888 * Syntax: constants introduced by new-style packages ('definition',
  3889 'abbreviation' etc.) are passed through the syntax module in
  3890 ``authentic mode''. This means that associated mixfix annotations
  3891 really stick to such constants, independently of potential name space
  3892 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3893 trees are represented slightly differently, may need to adapt syntax
  3894 translations accordingly. Use CONST marker in 'translations' and
  3895 @{const_syntax} antiquotation in 'parse_translation' etc.
  3896 
  3897 * Legacy goal package: reduced interface to the bare minimum required
  3898 to keep existing proof scripts running.  Most other user-level
  3899 functions are now part of the OldGoals structure, which is *not* open
  3900 by default (consider isatool expandshort before open OldGoals).
  3901 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3902 these tend to cause confusion about the actual goal (!) context being
  3903 used here, which is not necessarily the same as the_context().
  3904 
  3905 * Command 'find_theorems': supports "*" wild-card in "name:"
  3906 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3907 support a specific search form (see ProofGeneral/CHANGES).
  3908 
  3909 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3910 by default, which means that "prems" (and also "fixed variables") are
  3911 suppressed from proof state output.  Note that the ProofGeneral
  3912 settings mechanism allows to change and save options persistently, but
  3913 older versions of Isabelle will fail to start up if a negative prems
  3914 limit is imposed.
  3915 
  3916 * Local theory targets may be specified by non-nested blocks of
  3917 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3918 contain definitions, theorems etc., including any derived mechanism
  3919 that has been implemented on top of these primitives.  This concept
  3920 generalizes the existing ``theorem (in ...)'' towards more versatility
  3921 and scalability.
  3922 
  3923 * Proof General interface: proper undo of final 'end' command;
  3924 discontinued Isabelle/classic mode (ML proof scripts).
  3925 
  3926 
  3927 *** Document preparation ***
  3928 
  3929 * Added antiquotation @{theory name} which prints the given name,
  3930 after checking that it refers to a valid ancestor theory in the
  3931 current context.
  3932 
  3933 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3934 check the given source text as ML type/structure, printing verbatim.
  3935 
  3936 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3937 "c args == rhs" given in the current context.  (Any number of
  3938 arguments may be given on the LHS.)
  3939 
  3940 
  3941 *** Pure ***
  3942 
  3943 * The 'class' package offers a combination of axclass and locale to
  3944 achieve Haskell-like type classes in Isabelle.  Definitions and
  3945 theorems within a class context produce both relative results (with
  3946 implicit parameters according to the locale context), and polymorphic
  3947 constants with qualified polymorphism (according to the class
  3948 context).  Within the body context of a 'class' target, a separate
  3949 syntax layer ("user space type system") takes care of converting
  3950 between global polymorphic consts and internal locale representation.
  3951 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3952 "isatool doc classes" provides a tutorial.
  3953 
  3954 * Generic code generator framework allows to generate executable
  3955 code for ML and Haskell (including Isabelle classes).  A short usage
  3956 sketch:
  3957 
  3958     internal compilation:
  3959         export_code <list of constants (term syntax)> in SML
  3960     writing SML code to a file:
  3961         export_code <list of constants (term syntax)> in SML <filename>
  3962     writing OCaml code to a file:
  3963         export_code <list of constants (term syntax)> in OCaml <filename>
  3964     writing Haskell code to a bunch of files:
  3965         export_code <list of constants (term syntax)> in Haskell <filename>
  3966 
  3967     evaluating closed propositions to True/False using code generation:
  3968         method ``eval''
  3969 
  3970 Reasonable default setup of framework in HOL.
  3971 
  3972 Theorem attributs for selecting and transforming function equations theorems:
  3973 
  3974     [code fun]:        select a theorem as function equation for a specific constant
  3975     [code fun del]:    deselect a theorem as function equation for a specific constant
  3976     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3977     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3978 
  3979 User-defined serializations (target in {SML, OCaml, Haskell}):
  3980 
  3981     code_const <and-list of constants (term syntax)>
  3982       {(target) <and-list of const target syntax>}+
  3983 
  3984     code_type <and-list of type constructors>
  3985       {(target) <and-list of type target syntax>}+
  3986 
  3987     code_instance <and-list of instances>
  3988       {(target)}+
  3989         where instance ::= <type constructor> :: <class>
  3990 
  3991     code_class <and_list of classes>
  3992       {(target) <and-list of class target syntax>}+
  3993         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3994 
  3995 code_instance and code_class only are effective to target Haskell.
  3996 
  3997 For example usage see src/HOL/ex/Codegenerator.thy and
  3998 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3999 generation from Isabelle/HOL theories is available via "isatool doc
  4000 codegen".
  4001 
  4002 * Code generator: consts in 'consts_code' Isar commands are now
  4003 referred to by usual term syntax (including optional type
  4004 annotations).
  4005 
  4006 * Command 'no_translations' removes translation rules from theory
  4007 syntax.
  4008 
  4009 * Overloaded definitions are now actually checked for acyclic
  4010 dependencies.  The overloading scheme is slightly more general than
  4011 that of Haskell98, although Isabelle does not demand an exact
  4012 correspondence to type class and instance declarations.
  4013 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  4014 exotic versions of overloading -- at the discretion of the user!
  4015 
  4016 Polymorphic constants are represented via type arguments, i.e. the
  4017 instantiation that matches an instance against the most general
  4018 declaration given in the signature.  For example, with the declaration
  4019 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  4020 as c(nat).  Overloading is essentially simultaneous structural
  4021 recursion over such type arguments.  Incomplete specification patterns
  4022 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  4023 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  4024 Command 'print_theory' outputs the normalized system of recursive
  4025 equations, see section "definitions".
  4026 
  4027 * Configuration options are maintained within the theory or proof
  4028 context (with name and type bool/int/string), providing a very simple
  4029 interface to a poor-man's version of general context data.  Tools may
  4030 declare options in ML (e.g. using Attrib.config_int) and then refer to
  4031 these values using Config.get etc.  Users may change options via an
  4032 associated attribute of the same name.  This form of context
  4033 declaration works particularly well with commands 'declare' or
  4034 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  4035 very easy to avoid global references, which would not observe Isar
  4036 toplevel undo/redo and fail to work with multithreading.
  4037 
  4038 Various global ML references of Pure and HOL have been turned into
  4039 configuration options:
  4040 
  4041   Unify.search_bound		unify_search_bound
  4042   Unify.trace_bound		unify_trace_bound
  4043   Unify.trace_simp		unify_trace_simp
  4044   Unify.trace_types		unify_trace_types
  4045   Simplifier.simp_depth_limit	simp_depth_limit
  4046   Blast.depth_limit		blast_depth_limit
  4047   DatatypeProp.dtK		datatype_distinctness_limit
  4048   fast_arith_neq_limit  	fast_arith_neq_limit
  4049   fast_arith_split_limit	fast_arith_split_limit
  4050 
  4051 * Named collections of theorems may be easily installed as context
  4052 data using the functor NamedThmsFun (see also
  4053 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  4054 attributes; there is also a toplevel print command.  This facility is
  4055 just a common case of general context data, which is the preferred way
  4056 for anything more complex than just a list of facts in canonical
  4057 order.
  4058 
  4059 * Isar: command 'declaration' augments a local theory by generic
  4060 declaration functions written in ML.  This enables arbitrary content
  4061 being added to the context, depending on a morphism that tells the
  4062 difference of the original declaration context wrt. the application
  4063 context encountered later on.
  4064 
  4065 * Isar: proper interfaces for simplification procedures.  Command
  4066 'simproc_setup' declares named simprocs (with match patterns, and body
  4067 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  4068 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  4069 
  4070 * Isar: an extra pair of brackets around attribute declarations
  4071 abbreviates a theorem reference involving an internal dummy fact,
  4072 which will be ignored later --- only the effect of the attribute on
  4073 the background context will persist.  This form of in-place
  4074 declarations is particularly useful with commands like 'declare' and
  4075 'using', for example ``have A using [[simproc a]] by simp''.
  4076 
  4077 * Isar: method "assumption" (and implicit closing of subproofs) now
  4078 takes simple non-atomic goal assumptions into account: after applying
  4079 an assumption as a rule the resulting subgoals are solved by atomic
  4080 assumption steps.  This is particularly useful to finish 'obtain'
  4081 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  4082 without referring to the original premise "!!x. P x ==> thesis" in the
  4083 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  4084 more permissive.
  4085 
  4086 * Isar: implicit use of prems from the Isar proof context is
  4087 considered a legacy feature.  Common applications like ``have A .''
  4088 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  4089 referencing facts explicitly here improves readability and
  4090 maintainability of proof texts.
  4091 
  4092 * Isar: improper proof element 'guess' is like 'obtain', but derives
  4093 the obtained context from the course of reasoning!  For example:
  4094 
  4095   assume "EX x y. A x & B y"   -- "any previous fact"
  4096   then guess x and y by clarify
  4097 
  4098 This technique is potentially adventurous, depending on the facts and
  4099 proof tools being involved here.
  4100 
  4101 * Isar: known facts from the proof context may be specified as literal
  4102 propositions, using ASCII back-quote syntax.  This works wherever
  4103 named facts used to be allowed so far, in proof commands, proof
  4104 methods, attributes etc.  Literal facts are retrieved from the context
  4105 according to unification of type and term parameters.  For example,
  4106 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  4107 theorems in the current context, then these are valid literal facts:
  4108 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  4109 
  4110 There is also a proof method "fact" which does the same composition
  4111 for explicit goal states, e.g. the following proof texts coincide with
  4112 certain special cases of literal facts:
  4113 
  4114   have "A" by fact                 ==  note `A`
  4115   have "A ==> B" by fact           ==  note `A ==> B`
  4116   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  4117   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  4118 
  4119 * Isar: ":" (colon) is no longer a symbolic identifier character in
  4120 outer syntax.  Thus symbolic identifiers may be used without
  4121 additional white space in declarations like this: ``assume *: A''.
  4122 
  4123 * Isar: 'print_facts' prints all local facts of the current context,
  4124 both named and unnamed ones.
  4125 
  4126 * Isar: 'def' now admits simultaneous definitions, e.g.:
  4127 
  4128   def x == "t" and y == "u"
  4129 
  4130 * Isar: added command 'unfolding', which is structurally similar to
  4131 'using', but affects both the goal state and facts by unfolding given
  4132 rewrite rules.  Thus many occurrences of the 'unfold' method or
  4133 'unfolded' attribute may be replaced by first-class proof text.
  4134 
  4135 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  4136 and command 'unfolding' now all support object-level equalities
  4137 (potentially conditional).  The underlying notion of rewrite rule is
  4138 analogous to the 'rule_format' attribute, but *not* that of the
  4139 Simplifier (which is usually more generous).
  4140 
  4141 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  4142 premises of a theorem by n. Useful in conjunction with drule.
  4143 
  4144 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  4145 method expression within a sandbox consisting of the first N
  4146 sub-goals, which need to exist.  For example, ``simp_all [3]''
  4147 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  4148 simplifies all new goals that emerge from applying rule foo to the
  4149 originally first one.
  4150 
  4151 * Isar: schematic goals are no longer restricted to higher-order
  4152 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  4153 expected.
  4154 
  4155 * Isar: the conclusion of a long theorem statement is now either
  4156 'shows' (a simultaneous conjunction, as before), or 'obtains'
  4157 (essentially a disjunction of cases with local parameters and
  4158 assumptions).  The latter allows to express general elimination rules
  4159 adequately; in this notation common elimination rules look like this:
  4160 
  4161   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  4162     assumes "EX x. P x"
  4163     obtains x where "P x"
  4164 
  4165   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  4166     assumes "A & B"
  4167     obtains A and B
  4168 
  4169   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  4170     assumes "A | B"
  4171     obtains
  4172       A
  4173     | B
  4174 
  4175 The subsequent classical rules even refer to the formal "thesis"
  4176 explicitly:
  4177 
  4178   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  4179     obtains "~ thesis"
  4180 
  4181   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  4182     obtains "thesis ==> something"
  4183 
  4184 The actual proof of an 'obtains' statement is analogous to that of the
  4185 Isar proof element 'obtain', only that there may be several cases.
  4186 Optional case names may be specified in parentheses; these will be
  4187 available both in the present proof and as annotations in the
  4188 resulting rule, for later use with the 'cases' method (cf. attribute
  4189 case_names).
  4190 
  4191 * Isar: the assumptions of a long theorem statement are available as
  4192 "assms" fact in the proof context.  This is more appropriate than the
  4193 (historical) "prems", which refers to all assumptions of the current
  4194 context, including those from the target locale, proof body etc.
  4195 
  4196 * Isar: 'print_statement' prints theorems from the current theory or
  4197 proof context in long statement form, according to the syntax of a
  4198 top-level lemma.
  4199 
  4200 * Isar: 'obtain' takes an optional case name for the local context
  4201 introduction rule (default "that").
  4202 
  4203 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  4204 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  4205 to occur.
  4206 
  4207 * Pure: syntax "CONST name" produces a fully internalized constant
  4208 according to the current context.  This is particularly useful for
  4209 syntax translations that should refer to internal constant
  4210 representations independently of name spaces.
  4211 
  4212 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  4213 instead of "FOO ". This allows multiple binder declarations to coexist
  4214 in the same context.  INCOMPATIBILITY.
  4215 
  4216 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  4217 primitive that also works in a locale context (both for constants and
  4218 fixed variables). Type declaration and internal syntactic representation
  4219 of given constants retrieved from the context. Likewise, the
  4220 'no_notation' command allows to remove given syntax annotations from the
  4221 current context.
  4222 
  4223 * Isar/locales: new derived specification elements 'axiomatization',
  4224 'definition', 'abbreviation', which support type-inference, admit
  4225 object-level specifications (equality, equivalence).  See also the
  4226 isar-ref manual.  Examples:
  4227 
  4228   axiomatization
  4229     eq  (infix "===" 50) where
  4230     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  4231 
  4232   definition "f x y = x + y + 1"
  4233   definition g where "g x = f x x"
  4234 
  4235   abbreviation
  4236     neq  (infix "=!=" 50) where
  4237     "x =!= y == ~ (x === y)"
  4238 
  4239 These specifications may be also used in a locale context.  Then the
  4240 constants being introduced depend on certain fixed parameters, and the
  4241 constant name is qualified by the locale base name.  An internal
  4242 abbreviation takes care for convenient input and output, making the
  4243 parameters implicit and using the original short name.  See also
  4244 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  4245 entities from a monomorphic theory.
  4246 
  4247 Presently, abbreviations are only available 'in' a target locale, but
  4248 not inherited by general import expressions.  Also note that
  4249 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  4250 'translations' in common applications.  The "no_abbrevs" print mode
  4251 prevents folding of abbreviations in term output.
  4252 
  4253 Concrete syntax is attached to specified constants in internal form,
  4254 independently of name spaces.  The parse tree representation is
  4255 slightly different -- use 'notation' instead of raw 'syntax', and
  4256 'translations' with explicit "CONST" markup to accommodate this.
  4257 
  4258 * Pure/Isar: unified syntax for new-style specification mechanisms
  4259 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  4260 full type inference and dummy patterns ("_").  For example:
  4261 
  4262   definition "K x _ = x"
  4263 
  4264   inductive conj for A B
  4265   where "A ==> B ==> conj A B"
  4266 
  4267 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  4268 the current context.  Print mode "no_abbrevs" prevents inversion of
  4269 abbreviations on output.
  4270 
  4271 * Isar/locales: improved parameter handling: use of locales "var" and
  4272 "struct" no longer necessary; - parameter renamings are no longer
  4273 required to be injective.  For example, this allows to define
  4274 endomorphisms as locale endom = homom mult mult h.
  4275 
  4276 * Isar/locales: changed the way locales with predicates are defined.
  4277 Instead of accumulating the specification, the imported expression is
  4278 now an interpretation.  INCOMPATIBILITY: different normal form of
  4279 locale expressions.  In particular, in interpretations of locales with
  4280 predicates, goals repesenting already interpreted fragments are not
  4281 removed automatically.  Use methods `intro_locales' and
  4282 `unfold_locales'; see below.
  4283 
  4284 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  4285 provide backward reasoning on locales predicates.  The methods are
  4286 aware of interpretations and discharge corresponding goals.
  4287 `intro_locales' is less aggressive then `unfold_locales' and does not
  4288 unfold predicates to assumptions.
  4289 
  4290 * Isar/locales: the order in which locale fragments are accumulated
  4291 has changed.  This enables to override declarations from fragments due
  4292 to interpretations -- for example, unwanted simp rules.
  4293 
  4294 * Isar/locales: interpretation in theories and proof contexts has been
  4295 extended.  One may now specify (and prove) equations, which are
  4296 unfolded in interpreted theorems.  This is useful for replacing
  4297 defined concepts (constants depending on locale parameters) by
  4298 concepts already existing in the target context.  Example:
  4299 
  4300   interpretation partial_order ["op <= :: [int, int] => bool"]
  4301     where "partial_order.less (op <=) (x::int) y = (x < y)"
  4302 
  4303 Typically, the constant `partial_order.less' is created by a
  4304 definition specification element in the context of locale
  4305 partial_order.
  4306 
  4307 * Method "induct": improved internal context management to support
  4308 local fixes and defines on-the-fly. Thus explicit meta-level
  4309 connectives !!  and ==> are rarely required anymore in inductive goals
  4310 (using object-logic connectives for this purpose has been long
  4311 obsolete anyway). Common proof patterns are explained in
  4312 src/HOL/Induct/Common_Patterns.thy, see also
  4313 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  4314 examples.
  4315 
  4316 * Method "induct": improved handling of simultaneous goals. Instead of
  4317 introducing object-level conjunction, the statement is now split into
  4318 several conclusions, while the corresponding symbolic cases are nested
  4319 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  4320 see src/HOL/Induct/Common_Patterns.thy, for example.
  4321 
  4322 * Method "induct": mutual induction rules are now specified as a list
  4323 of rule sharing the same induction cases. HOL packages usually provide
  4324 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  4325 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  4326 mutual induction rules differently, i.e. like this:
  4327 
  4328   (induct rule: foo_bar.inducts)
  4329   (induct set: foo bar)
  4330   (induct pred: foo bar)
  4331   (induct type: foo bar)
  4332 
  4333 The ML function ProjectRule.projections turns old-style rules into the
  4334 new format.
  4335 
  4336 * Method "coinduct": dual of induction, see
  4337 src/HOL/Library/Coinductive_List.thy for various examples.
  4338 
  4339 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  4340 considered a legacy feature.
  4341 
  4342 * Attribute "symmetric" produces result with standardized schematic
  4343 variables (index 0).  Potential INCOMPATIBILITY.
  4344 
  4345 * Simplifier: by default the simplifier trace only shows top level
  4346 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  4347 default. Thus there is less danger of being flooded by the trace. The
  4348 trace indicates where parts have been suppressed.
  4349   
  4350 * Provers/classical: removed obsolete classical version of elim_format
  4351 attribute; classical elim/dest rules are now treated uniformly when
  4352 manipulating the claset.
  4353 
  4354 * Provers/classical: stricter checks to ensure that supplied intro,
  4355 dest and elim rules are well-formed; dest and elim rules must have at
  4356 least one premise.
  4357 
  4358 * Provers/classical: attributes dest/elim/intro take an optional
  4359 weight argument for the rule (just as the Pure versions).  Weights are
  4360 ignored by automated tools, but determine the search order of single
  4361 rule steps.
  4362 
  4363 * Syntax: input syntax now supports dummy variable binding "%_. b",
  4364 where the body does not mention the bound variable.  Note that dummy
  4365 patterns implicitly depend on their context of bounds, which makes
  4366 "{_. _}" match any set comprehension as expected.  Potential
  4367 INCOMPATIBILITY -- parse translations need to cope with syntactic
  4368 constant "_idtdummy" in the binding position.
  4369 
  4370 * Syntax: removed obsolete syntactic constant "_K" and its associated
  4371 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  4372 for example "A -> B" => "Pi A (%_. B)".
  4373 
  4374 * Pure: 'class_deps' command visualizes the subclass relation, using
  4375 the graph browser tool.
  4376 
  4377 * Pure: 'print_theory' now suppresses certain internal declarations by
  4378 default; use '!' option for full details.
  4379 
  4380 
  4381 *** HOL ***
  4382 
  4383 * Method "metis" proves goals by applying the Metis general-purpose
  4384 resolution prover (see also http://gilith.com/software/metis/).
  4385 Examples are in the directory MetisExamples.  WARNING: the
  4386 Isabelle/HOL-Metis integration does not yet work properly with
  4387 multi-threading.
  4388   
  4389 * Command 'sledgehammer' invokes external automatic theorem provers as
  4390 background processes.  It generates calls to the "metis" method if
  4391 successful. These can be pasted into the proof.  Users do not have to
  4392 wait for the automatic provers to return.  WARNING: does not really
  4393 work with multi-threading.
  4394 
  4395 * New "auto_quickcheck" feature tests outermost goal statements for
  4396 potential counter-examples.  Controlled by ML references
  4397 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  4398 5000 milliseconds).  Fails silently if statements is outside of
  4399 executable fragment, or any other codgenerator problem occurs.
  4400 
  4401 * New constant "undefined" with axiom "undefined x = undefined".
  4402 
  4403 * Added class "HOL.eq", allowing for code generation with polymorphic
  4404 equality.
  4405 
  4406 * Some renaming of class constants due to canonical name prefixing in
  4407 the new 'class' package:
  4408 
  4409     HOL.abs ~> HOL.abs_class.abs
  4410     HOL.divide ~> HOL.divide_class.divide
  4411     0 ~> HOL.zero_class.zero
  4412     1 ~> HOL.one_class.one
  4413     op + ~> HOL.plus_class.plus
  4414     op - ~> HOL.minus_class.minus
  4415     uminus ~> HOL.minus_class.uminus
  4416     op * ~> HOL.times_class.times
  4417     op < ~> HOL.ord_class.less
  4418     op <= > HOL.ord_class.less_eq
  4419     Nat.power ~> Power.power_class.power
  4420     Nat.size ~> Nat.size_class.size
  4421     Numeral.number_of ~> Numeral.number_class.number_of
  4422     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  4423     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  4424     Orderings.min ~> Orderings.ord_class.min
  4425     Orderings.max ~> Orderings.ord_class.max
  4426     Divides.op div ~> Divides.div_class.div
  4427     Divides.op mod ~> Divides.div_class.mod
  4428     Divides.op dvd ~> Divides.div_class.dvd
  4429 
  4430 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  4431 
  4432 a) User-defined constants using any of the names "plus", "minus",
  4433 "times", "less" or "less_eq". The standard syntax translations for
  4434 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  4435 names.
  4436 
  4437 b) Variables named "plus", "minus", "times", "less", "less_eq"
  4438 INCOMPATIBILITY: use more specific names.
  4439 
  4440 c) Permutative equations (e.g. "a + b = b + a")
  4441 Since the change of names also changes the order of terms, permutative
  4442 rewrite rules may get applied in a different order. Experience shows
  4443 that this is rarely the case (only two adaptions in the whole Isabelle
  4444 distribution).  INCOMPATIBILITY: rewrite proofs
  4445 
  4446 d) ML code directly refering to constant names
  4447 This in general only affects hand-written proof tactics, simprocs and
  4448 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  4449 Consider using @{const_name} antiquotation.
  4450 
  4451 * New class "default" with associated constant "default".
  4452 
  4453 * Function "sgn" is now overloaded and available on int, real, complex
  4454 (and other numeric types), using class "sgn".  Two possible defs of
  4455 sgn are given as equational assumptions in the classes sgn_if and
  4456 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  4457 INCOMPATIBILITY.
  4458 
  4459 * Locale "partial_order" now unified with class "order" (cf. theory
  4460 Orderings), added parameter "less".  INCOMPATIBILITY.
  4461 
  4462 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  4463 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  4464 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  4465 
  4466 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  4467 changed order of proof goals in instance proofs.
  4468 
  4469 * The transitivity reasoner for partial and linear orders is set up
  4470 for classes "order" and "linorder".  Instances of the reasoner are available
  4471 in all contexts importing or interpreting the corresponding locales.
  4472 Method "order" invokes the reasoner separately; the reasoner
  4473 is also integrated with the Simplifier as a solver.  Diagnostic
  4474 command 'print_orders' shows the available instances of the reasoner
  4475 in the current context.
  4476 
  4477 * Localized monotonicity predicate in theory "Orderings"; integrated
  4478 lemmas max_of_mono and min_of_mono with this predicate.
  4479 INCOMPATIBILITY.
  4480 
  4481 * Formulation of theorem "dense" changed slightly due to integration
  4482 with new class dense_linear_order.
  4483 
  4484 * Uniform lattice theory development in HOL.
  4485 
  4486     constants "meet" and "join" now named "inf" and "sup"
  4487     constant "Meet" now named "Inf"
  4488 
  4489     classes "meet_semilorder" and "join_semilorder" now named
  4490       "lower_semilattice" and "upper_semilattice"
  4491     class "lorder" now named "lattice"
  4492     class "comp_lat" now named "complete_lattice"
  4493 
  4494     Instantiation of lattice classes allows explicit definitions
  4495     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  4496 
  4497   INCOMPATIBILITY.  Theorem renames:
  4498 
  4499     meet_left_le            ~> inf_le1
  4500     meet_right_le           ~> inf_le2
  4501     join_left_le            ~> sup_ge1
  4502     join_right_le           ~> sup_ge2
  4503     meet_join_le            ~> inf_sup_ord
  4504     le_meetI                ~> le_infI
  4505     join_leI                ~> le_supI
  4506     le_meet                 ~> le_inf_iff
  4507     le_join                 ~> ge_sup_conv
  4508     meet_idempotent         ~> inf_idem
  4509     join_idempotent         ~> sup_idem
  4510     meet_comm               ~> inf_commute
  4511     join_comm               ~> sup_commute
  4512     meet_leI1               ~> le_infI1
  4513     meet_leI2               ~> le_infI2
  4514     le_joinI1               ~> le_supI1
  4515     le_joinI2               ~> le_supI2
  4516     meet_assoc              ~> inf_assoc
  4517     join_assoc              ~> sup_assoc
  4518     meet_left_comm          ~> inf_left_commute
  4519     meet_left_idempotent    ~> inf_left_idem
  4520     join_left_comm          ~> sup_left_commute
  4521     join_left_idempotent    ~> sup_left_idem
  4522     meet_aci                ~> inf_aci
  4523     join_aci                ~> sup_aci
  4524     le_def_meet             ~> le_iff_inf
  4525     le_def_join             ~> le_iff_sup
  4526     join_absorp2            ~> sup_absorb2
  4527     join_absorp1            ~> sup_absorb1
  4528     meet_absorp1            ~> inf_absorb1
  4529     meet_absorp2            ~> inf_absorb2
  4530     meet_join_absorp        ~> inf_sup_absorb
  4531     join_meet_absorp        ~> sup_inf_absorb
  4532     distrib_join_le         ~> distrib_sup_le
  4533     distrib_meet_le         ~> distrib_inf_le
  4534 
  4535     add_meet_distrib_left   ~> add_inf_distrib_left
  4536     add_join_distrib_left   ~> add_sup_distrib_left
  4537     is_join_neg_meet        ~> is_join_neg_inf
  4538     is_meet_neg_join        ~> is_meet_neg_sup
  4539     add_meet_distrib_right  ~> add_inf_distrib_right
  4540     add_join_distrib_right  ~> add_sup_distrib_right
  4541     add_meet_join_distribs  ~> add_sup_inf_distribs
  4542     join_eq_neg_meet        ~> sup_eq_neg_inf
  4543     meet_eq_neg_join        ~> inf_eq_neg_sup
  4544     add_eq_meet_join        ~> add_eq_inf_sup
  4545     meet_0_imp_0            ~> inf_0_imp_0
  4546     join_0_imp_0            ~> sup_0_imp_0
  4547     meet_0_eq_0             ~> inf_0_eq_0
  4548     join_0_eq_0             ~> sup_0_eq_0
  4549     neg_meet_eq_join        ~> neg_inf_eq_sup
  4550     neg_join_eq_meet        ~> neg_sup_eq_inf
  4551     join_eq_if              ~> sup_eq_if
  4552 
  4553     mono_meet               ~> mono_inf
  4554     mono_join               ~> mono_sup
  4555     meet_bool_eq            ~> inf_bool_eq
  4556     join_bool_eq            ~> sup_bool_eq
  4557     meet_fun_eq             ~> inf_fun_eq
  4558     join_fun_eq             ~> sup_fun_eq
  4559     meet_set_eq             ~> inf_set_eq
  4560     join_set_eq             ~> sup_set_eq
  4561     meet1_iff               ~> inf1_iff
  4562     meet2_iff               ~> inf2_iff
  4563     meet1I                  ~> inf1I
  4564     meet2I                  ~> inf2I
  4565     meet1D1                 ~> inf1D1
  4566     meet2D1                 ~> inf2D1
  4567     meet1D2                 ~> inf1D2
  4568     meet2D2                 ~> inf2D2
  4569     meet1E                  ~> inf1E
  4570     meet2E                  ~> inf2E
  4571     join1_iff               ~> sup1_iff
  4572     join2_iff               ~> sup2_iff
  4573     join1I1                 ~> sup1I1
  4574     join2I1                 ~> sup2I1
  4575     join1I1                 ~> sup1I1
  4576     join2I2                 ~> sup1I2
  4577     join1CI                 ~> sup1CI
  4578     join2CI                 ~> sup2CI
  4579     join1E                  ~> sup1E
  4580     join2E                  ~> sup2E
  4581 
  4582     is_meet_Meet            ~> is_meet_Inf
  4583     Meet_bool_def           ~> Inf_bool_def
  4584     Meet_fun_def            ~> Inf_fun_def
  4585     Meet_greatest           ~> Inf_greatest
  4586     Meet_lower              ~> Inf_lower
  4587     Meet_set_def            ~> Inf_set_def
  4588 
  4589     Sup_def                 ~> Sup_Inf
  4590     Sup_bool_eq             ~> Sup_bool_def
  4591     Sup_fun_eq              ~> Sup_fun_def
  4592     Sup_set_eq              ~> Sup_set_def
  4593 
  4594     listsp_meetI            ~> listsp_infI
  4595     listsp_meet_eq          ~> listsp_inf_eq
  4596 
  4597     meet_min                ~> inf_min
  4598     join_max                ~> sup_max
  4599 
  4600 * Added syntactic class "size"; overloaded constant "size" now has
  4601 type "'a::size ==> bool"
  4602 
  4603 * Internal reorganisation of `size' of datatypes: size theorems
  4604 "foo.size" are no longer subsumed by "foo.simps" (but are still
  4605 simplification rules by default!); theorems "prod.size" now named
  4606 "*.size".
  4607 
  4608 * Class "div" now inherits from class "times" rather than "type".
  4609 INCOMPATIBILITY.
  4610 
  4611 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  4612 Linorder etc.  have disappeared; operations defined in terms of
  4613 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  4614 
  4615 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  4616 
  4617 * HOL-Word: New extensive library and type for generic, fixed size
  4618 machine words, with arithemtic, bit-wise, shifting and rotating
  4619 operations, reflection into int, nat, and bool lists, automation for
  4620 linear arithmetic (by automatic reflection into nat or int), including
  4621 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  4622 arithmetic type classes, supporting automatic simplification of
  4623 numerals on all operations.
  4624 
  4625 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  4626 
  4627 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  4628 
  4629 * Code generator library theories:
  4630   - Code_Integer represents HOL integers by big integer literals in target
  4631     languages.
  4632   - Code_Char represents HOL characters by character literals in target
  4633     languages.
  4634   - Code_Char_chr like Code_Char, but also offers treatment of character
  4635     codes; includes Code_Integer.
  4636   - Executable_Set allows to generate code for finite sets using lists.
  4637   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4638     denominator).
  4639   - Executable_Real implements a subset of real numbers, namly those
  4640     representable by rational numbers.
  4641   - Efficient_Nat implements natural numbers by integers, which in general will
  4642     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4643     includes Code_Integer.
  4644   - Code_Index provides an additional datatype index which is mapped to
  4645     target-language built-in integers.
  4646   - Code_Message provides an additional datatype message_string which is isomorphic to
  4647     strings; messages are mapped to target-language strings.
  4648 
  4649 * New package for inductive predicates
  4650 
  4651   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4652 
  4653     inductive
  4654       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4655       for z_1 :: U_1 and ... and z_n :: U_m
  4656     where
  4657       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4658     | ...
  4659 
  4660   with full support for type-inference, rather than
  4661 
  4662     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4663 
  4664     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4665     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4666 
  4667     inductive "s z_1 ... z_m"
  4668     intros
  4669       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4670       ...
  4671 
  4672   For backward compatibility, there is a wrapper allowing inductive
  4673   sets to be defined with the new package via
  4674 
  4675     inductive_set
  4676       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4677       for z_1 :: U_1 and ... and z_n :: U_m
  4678     where
  4679       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4680     | ...
  4681 
  4682   or
  4683 
  4684     inductive_set
  4685       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4686       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4687       for z_1 :: U_1 and ... and z_n :: U_m
  4688     where
  4689       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4690     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4691     | ...
  4692 
  4693   if the additional syntax "p ..." is required.
  4694 
  4695   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4696   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4697 
  4698   INCOMPATIBILITIES:
  4699 
  4700   - Since declaration and definition of inductive sets or predicates
  4701     is no longer separated, abbreviations involving the newly
  4702     introduced sets or predicates must be specified together with the
  4703     introduction rules after the 'where' keyword (see above), rather
  4704     than before the actual inductive definition.
  4705 
  4706   - The variables in induction and elimination rules are now
  4707     quantified in the order of their occurrence in the introduction
  4708     rules, rather than in alphabetical order. Since this may break
  4709     some proofs, these proofs either have to be repaired, e.g. by
  4710     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4711     statements of the form
  4712 
  4713       case (rule_i a_i_1 ... a_i_{k_i})
  4714 
  4715     or the old order of quantification has to be restored by explicitly adding
  4716     meta-level quantifiers in the introduction rules, i.e.
  4717 
  4718       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4719 
  4720   - The format of the elimination rules is now
  4721 
  4722       p z_1 ... z_m x_1 ... x_n ==>
  4723         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4724         ==> ... ==> P
  4725 
  4726     for predicates and
  4727 
  4728       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4729         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4730         ==> ... ==> P
  4731 
  4732     for sets rather than
  4733 
  4734       x : s z_1 ... z_m ==>
  4735         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4736         ==> ... ==> P
  4737 
  4738     This may require terms in goals to be expanded to n-tuples
  4739     (e.g. using case_tac or simplification with the split_paired_all
  4740     rule) before the above elimination rule is applicable.
  4741 
  4742   - The elimination or case analysis rules for (mutually) inductive
  4743     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4744     list of rules "p_1_..._p_k.elims" is no longer available.
  4745 
  4746 * New package "function"/"fun" for general recursive functions,
  4747 supporting mutual and nested recursion, definitions in local contexts,
  4748 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4749 for small examples, and the separate tutorial on the function
  4750 package. The old recdef "package" is still available as before, but
  4751 users are encouraged to use the new package.
  4752 
  4753 * Method "lexicographic_order" automatically synthesizes termination
  4754 relations as lexicographic combinations of size measures. 
  4755 
  4756 * Case-expressions allow arbitrary constructor-patterns (including
  4757 "_") and take their order into account, like in functional
  4758 programming.  Internally, this is translated into nested
  4759 case-expressions; missing cases are added and mapped to the predefined
  4760 constant "undefined". In complicated cases printing may no longer show
  4761 the original input but the internal form. Lambda-abstractions allow
  4762 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4763 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4764 variable.
  4765 
  4766 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4767 is an abbreviation for "of_nat :: nat => int". The simplification
  4768 rules for "of_nat" have been changed to work like "int" did
  4769 previously.  Potential INCOMPATIBILITY:
  4770   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4771   - of_nat_diff and of_nat_mult are no longer default simp rules
  4772 
  4773 * Method "algebra" solves polynomial equations over (semi)rings using
  4774 Groebner bases. The (semi)ring structure is defined by locales and the
  4775 tool setup depends on that generic context. Installing the method for
  4776 a specific type involves instantiating the locale and possibly adding
  4777 declarations for computation on the coefficients.  The method is
  4778 already instantiated for natural numbers and for the axiomatic class
  4779 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4780 CALCULEMUS 2007 for the general principles underlying this
  4781 architecture of context-aware proof-tools.
  4782 
  4783 * Method "ferrack" implements quantifier elimination over
  4784 special-purpose dense linear orders using locales (analogous to
  4785 "algebra"). The method is already installed for class
  4786 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4787 rat, etc.
  4788 
  4789 * Former constant "List.op @" now named "List.append".  Use ML
  4790 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4791 circumvent possible incompatibilities when working on ML level.
  4792 
  4793 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4794 
  4795 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4796 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4797 
  4798 * New syntax for Haskell-like list comprehension (input only), eg.
  4799 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4800 
  4801 * The special syntax for function "filter" has changed from [x :
  4802 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4803 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4804 
  4805 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4806 defined on nat only, as an abbreviation for [a..<Suc b]
  4807 INCOMPATIBILITY.
  4808 
  4809 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4810 
  4811 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4812 
  4813 * New lemma collection field_simps (an extension of ring_simps) for
  4814 manipulating (in)equations involving division. Multiplies with all
  4815 denominators that can be proved to be non-zero (in equations) or
  4816 positive/negative (in inequations).
  4817 
  4818 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4819 have been improved and renamed to ring_simps, group_simps and
  4820 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4821 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4822 
  4823 * Theory Library/Commutative_Ring: switched from recdef to function
  4824 package; constants add, mul, pow now curried.  Infix syntax for
  4825 algebraic operations.
  4826 
  4827 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4828 INCOMPATIBILITY.
  4829 
  4830 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4831 INCOMPATIBILITY.
  4832 
  4833 * HOL/records: generalised field-update to take a function on the
  4834 field rather than the new value: r(|A := x|) is translated to A_update
  4835 (K x) r The K-combinator that is internally used is called K_record.
  4836 INCOMPATIBILITY: Usage of the plain update functions has to be
  4837 adapted.
  4838  
  4839 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4840 * x = 0, which are required for a semiring.  Richer structures do not
  4841 inherit from semiring_0 anymore, because this property is a theorem
  4842 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4843 there is more to prove, but this is mostly trivial.
  4844 
  4845 * Class "recpower" is generalized to arbitrary monoids, not just
  4846 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4847 commutativity or semiring properties additionally.
  4848 
  4849 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4850 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4851 better use 'abbreviation'.
  4852 
  4853 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4854 
  4855 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4856 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4857 significant changes for setting up numeral syntax for types:
  4858   - New constants Numeral.pred and Numeral.succ instead
  4859       of former Numeral.bin_pred and Numeral.bin_succ.
  4860   - Use integer operations instead of bin_add, bin_mult and so on.
  4861   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4862   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4863 
  4864 See src/HOL/Integ/IntArith.thy for an example setup.
  4865 
  4866 * Command 'normal_form' computes the normal form of a term that may
  4867 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4868 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4869 heavy-duty computations because the functions are compiled to ML
  4870 first.  Correspondingly, a method "normalization" is provided.  See
  4871 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4872 
  4873 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4874 25 like -->); output depends on the "iff" print_mode, the default is
  4875 "A = B" (with priority 50).
  4876 
  4877 * Relations less (<) and less_eq (<=) are also available on type bool.
  4878 Modified syntax to disallow nesting without explicit parentheses,
  4879 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4880 INCOMPATIBILITY.
  4881 
  4882 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4883 
  4884 * Relation composition operator "op O" now has precedence 75 and binds
  4885 stronger than union and intersection. INCOMPATIBILITY.
  4886 
  4887 * The old set interval syntax "{m..n(}" (and relatives) has been
  4888 removed.  Use "{m..<n}" (and relatives) instead.
  4889 
  4890 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4891 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4892 ``declare [[simproc del: neq]]''.
  4893 
  4894 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4895 True/False.
  4896 
  4897 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4898 
  4899 * Theorem setsum_mult renamed to setsum_right_distrib.
  4900 
  4901 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4902 ``rule'' method.
  4903 
  4904 * Reimplemented methods "sat" and "satx", with several improvements:
  4905 goals no longer need to be stated as "<prems> ==> False", equivalences
  4906 (i.e. "=" on type bool) are handled, variable names of the form
  4907 "lit_<n>" are no longer reserved, significant speedup.
  4908 
  4909 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4910 zChaff is still supported as well.
  4911 
  4912 * 'inductive' and 'datatype': provide projections of mutual rules,
  4913 bundled as foo_bar.inducts;
  4914 
  4915 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4916 Library.
  4917 
  4918 * Library: moved theory Accessible_Part to main HOL.
  4919 
  4920 * Library: added theory Coinductive_List of potentially infinite lists
  4921 as greatest fixed-point.
  4922 
  4923 * Library: added theory AssocList which implements (finite) maps as
  4924 association lists.
  4925 
  4926 * Method "evaluation" solves goals (i.e. a boolean expression)
  4927 efficiently by compiling it to ML.  The goal is "proved" (via an
  4928 oracle) if it evaluates to True.
  4929 
  4930 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4931 also when invoked by the simplifier.  This results in the Simplifier
  4932 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4933 Configuration option fast_arith_split_limit=0 recovers the old
  4934 behavior.
  4935 
  4936 * Support for hex (0x20) and binary (0b1001) numerals.
  4937 
  4938 * New method: reify eqs (t), where eqs are equations for an
  4939 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4940 parameter, computes a term s::'b and a list xs::'a list and proves the
  4941 theorem I xs s = t. This is also known as reification or quoting. The
  4942 resulting theorem is applied to the subgoal to substitute t with I xs
  4943 s.  If t is omitted, the subgoal itself is reified.
  4944 
  4945 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4946 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4947 where f is supposed to be a computable function (in the sense of code
  4948 generattion). The method uses reify to compute s and xs as above then
  4949 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4950 r and finally gets the theorem t = r, which is again applied to the
  4951 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4952 
  4953 * Reflection: Automatic reification now handels binding, an example is
  4954 available in src/HOL/ex/ReflectionEx.thy
  4955 
  4956 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4957 command 'statespace' that is similar to 'record', but introduces an
  4958 abstract specification based on the locale infrastructure instead of
  4959 HOL types.  This leads to extra flexibility in composing state spaces,
  4960 in particular multiple inheritance and renaming of components.
  4961 
  4962 
  4963 *** HOL-Complex ***
  4964 
  4965 * Hyperreal: Functions root and sqrt are now defined on negative real
  4966 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4967 Nonnegativity side conditions have been removed from many lemmas, so
  4968 that more subgoals may now be solved by simplification; potential
  4969 INCOMPATIBILITY.
  4970 
  4971 * Real: new type classes formalize real normed vector spaces and
  4972 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4973 and norm :: 'a => real.
  4974 
  4975 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4976 reals into other types. The overloaded constant Reals :: 'a set is now
  4977 defined as range of_real; potential INCOMPATIBILITY.
  4978 
  4979 * Real: proper support for ML code generation, including 'quickcheck'.
  4980 Reals are implemented as arbitrary precision rationals.
  4981 
  4982 * Hyperreal: Several constants that previously worked only for the
  4983 reals have been generalized, so they now work over arbitrary vector
  4984 spaces. Type annotations may need to be added in some cases; potential
  4985 INCOMPATIBILITY.
  4986 
  4987   Infinitesimal  :: ('a::real_normed_vector) star set
  4988   HFinite        :: ('a::real_normed_vector) star set
  4989   HInfinite      :: ('a::real_normed_vector) star set
  4990   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4991   monad          :: ('a::real_normed_vector) star => 'a star set
  4992   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4993   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4994   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4995   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4996   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4997   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4998   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4999   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  5000   sgn            :: 'a::real_normed_vector => 'a
  5001   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  5002 
  5003 * Complex: Some complex-specific constants are now abbreviations for
  5004 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  5005 hnorm.  Other constants have been entirely removed in favor of the
  5006 polymorphic versions (INCOMPATIBILITY):
  5007 
  5008   approx        <-- capprox
  5009   HFinite       <-- CFinite
  5010   HInfinite     <-- CInfinite
  5011   Infinitesimal <-- CInfinitesimal
  5012   monad         <-- cmonad
  5013   galaxy        <-- cgalaxy
  5014   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  5015   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  5016   (ns)deriv     <-- (ns)cderiv
  5017 
  5018 
  5019 *** HOL-Algebra ***
  5020 
  5021 * Formalisation of ideals and the quotient construction over rings.
  5022 
  5023 * Order and lattice theory no longer based on records.
  5024 INCOMPATIBILITY.
  5025 
  5026 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  5027 greatest_closed.  INCOMPATIBILITY.
  5028 
  5029 * Method algebra is now set up via an attribute.  For examples see
  5030 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  5031 of algebraic structures.
  5032 
  5033 * Renamed theory CRing to Ring.
  5034 
  5035 
  5036 *** HOL-Nominal ***
  5037 
  5038 * Substantial, yet incomplete support for nominal datatypes (binding
  5039 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  5040 src/HOL/Nominal/Examples.  Prospective users should consult
  5041 http://isabelle.in.tum.de/nominal/
  5042 
  5043 
  5044 *** ML ***
  5045 
  5046 * ML basics: just one true type int, which coincides with IntInf.int
  5047 (even on SML/NJ).
  5048 
  5049 * ML within Isar: antiquotations allow to embed statically-checked
  5050 formal entities in the source, referring to the context available at
  5051 compile-time.  For example:
  5052 
  5053 ML {* @{sort "{zero,one}"} *}
  5054 ML {* @{typ "'a => 'b"} *}
  5055 ML {* @{term "%x. x"} *}
  5056 ML {* @{prop "x == y"} *}
  5057 ML {* @{ctyp "'a => 'b"} *}
  5058 ML {* @{cterm "%x. x"} *}
  5059 ML {* @{cprop "x == y"} *}
  5060 ML {* @{thm asm_rl} *}
  5061 ML {* @{thms asm_rl} *}
  5062 ML {* @{type_name c} *}
  5063 ML {* @{type_syntax c} *}
  5064 ML {* @{const_name c} *}
  5065 ML {* @{const_syntax c} *}
  5066 ML {* @{context} *}
  5067 ML {* @{theory} *}
  5068 ML {* @{theory Pure} *}
  5069 ML {* @{theory_ref} *}
  5070 ML {* @{theory_ref Pure} *}
  5071 ML {* @{simpset} *}
  5072 ML {* @{claset} *}
  5073 ML {* @{clasimpset} *}
  5074 
  5075 The same works for sources being ``used'' within an Isar context.
  5076 
  5077 * ML in Isar: improved error reporting; extra verbosity with
  5078 ML_Context.trace enabled.
  5079 
  5080 * Pure/General/table.ML: the join operations now works via exceptions
  5081 DUP/SAME instead of type option. This is simpler in simple cases, and
  5082 admits slightly more efficient complex applications.
  5083 
  5084 * Pure: 'advanced' translation functions (parse_translation etc.) now
  5085 use Context.generic instead of just theory.
  5086 
  5087 * Pure: datatype Context.generic joins theory/Proof.context and
  5088 provides some facilities for code that works in either kind of
  5089 context, notably GenericDataFun for uniform theory and proof data.
  5090 
  5091 * Pure: simplified internal attribute type, which is now always
  5092 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  5093 local (Proof.context) attributes have been discontinued, while
  5094 minimizing code duplication. Thm.rule_attribute and
  5095 Thm.declaration_attribute build canonical attributes; see also structure
  5096 Context for further operations on Context.generic, notably
  5097 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  5098 declarations and definitions.
  5099 
  5100 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  5101 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  5102 init only required for impure data. INCOMPATIBILITY: empty really need
  5103 to be empty (no dependencies on theory content!)
  5104 
  5105 * Pure/kernel: consts certification ignores sort constraints given in
  5106 signature declarations. (This information is not relevant to the
  5107 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  5108 potential INCOMPATIBILITY.
  5109 
  5110 * Pure: axiomatic type classes are now purely definitional, with
  5111 explicit proofs of class axioms and super class relations performed
  5112 internally. See Pure/axclass.ML for the main internal interfaces --
  5113 notably AxClass.define_class supercedes AxClass.add_axclass, and
  5114 AxClass.axiomatize_class/classrel/arity supersede
  5115 Sign.add_classes/classrel/arities.
  5116 
  5117 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  5118 global/local versions on theory vs. Proof.context have been
  5119 discontinued; Attrib.syntax and Method.syntax have been adapted
  5120 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  5121 attributes, methods, etc.
  5122 
  5123 * Pure: several functions of signature "... -> theory -> theory * ..."
  5124 have been reoriented to "... -> theory -> ... * theory" in order to
  5125 allow natural usage in combination with the ||>, ||>>, |-> and
  5126 fold_map combinators.
  5127 
  5128 * Pure: official theorem names (closed derivations) and additional
  5129 comments (tags) are now strictly separate.  Name hints -- which are
  5130 maintained as tags -- may be attached any time without affecting the
  5131 derivation.
  5132 
  5133 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  5134 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  5135 achieve the old behaviour.
  5136 
  5137 * Pure: the "Goal" constant is now called "prop", supporting a
  5138 slightly more general idea of ``protecting'' meta-level rule
  5139 statements.
  5140 
  5141 * Pure: Logic.(un)varify only works in a global context, which is now
  5142 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  5143 Logic.legacy_(un)varify as temporary workaround.
  5144 
  5145 * Pure: structure Name provides scalable operations for generating
  5146 internal variable names, notably Name.variants etc.  This replaces
  5147 some popular functions from term.ML:
  5148 
  5149   Term.variant		->  Name.variant
  5150   Term.variantlist	->  Name.variant_list
  5151   Term.invent_names	->  Name.invent_list
  5152 
  5153 Note that low-level renaming rarely occurs in new code -- operations
  5154 from structure Variable are used instead (see below).
  5155 
  5156 * Pure: structure Variable provides fundamental operations for proper
  5157 treatment of fixed/schematic variables in a context.  For example,
  5158 Variable.import introduces fixes for schematics of given facts and
  5159 Variable.export reverses the effect (up to renaming) -- this replaces
  5160 various freeze_thaw operations.
  5161 
  5162 * Pure: structure Goal provides simple interfaces for
  5163 init/conclude/finish and tactical prove operations (replacing former
  5164 Tactic.prove).  Goal.prove is the canonical way to prove results
  5165 within a given context; Goal.prove_global is a degraded version for
  5166 theory level goals, including a global Drule.standard.  Note that
  5167 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  5168 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  5169 in a locale context).
  5170 
  5171 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  5172 and type checking (Syntax.check_term etc.), with common combinations
  5173 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  5174 which are considered legacy and await removal.
  5175 
  5176 * Pure/Syntax: generic interfaces for type unchecking
  5177 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  5178 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  5179 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  5180 available for convenience, but refer to the very same operations using
  5181 a mere theory instead of a full context.
  5182 
  5183 * Isar: simplified treatment of user-level errors, using exception
  5184 ERROR of string uniformly.  Function error now merely raises ERROR,
  5185 without any side effect on output channels.  The Isar toplevel takes
  5186 care of proper display of ERROR exceptions.  ML code may use plain
  5187 handle/can/try; cat_error may be used to concatenate errors like this:
  5188 
  5189   ... handle ERROR msg => cat_error msg "..."
  5190 
  5191 Toplevel ML code (run directly or through the Isar toplevel) may be
  5192 embedded into the Isar toplevel with exception display/debug like
  5193 this:
  5194 
  5195   Isar.toplevel (fn () => ...)
  5196 
  5197 INCOMPATIBILITY, removed special transform_error facilities, removed
  5198 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  5199 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  5200 -- use plain ERROR instead.
  5201 
  5202 * Isar: theory setup now has type (theory -> theory), instead of a
  5203 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  5204 
  5205 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  5206 ProofContext.debug/verbose flags.
  5207 
  5208 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  5209 theory before entering a proof state.  Transactions now always see a
  5210 quasi-functional intermediate checkpoint, both in interactive and
  5211 batch mode.
  5212 
  5213 * Isar: simplified interfaces for outer syntax.  Renamed
  5214 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  5215 OuterSyntax.add_parsers -- this functionality is now included in
  5216 OuterSyntax.command etc.  INCOMPATIBILITY.
  5217 
  5218 * Simplifier: the simpset of a running simplification process now
  5219 contains a proof context (cf. Simplifier.the_context), which is the
  5220 very context that the initial simpset has been retrieved from (by
  5221 simpset_of/local_simpset_of).  Consequently, all plug-in components
  5222 (solver, looper etc.) may depend on arbitrary proof data.
  5223 
  5224 * Simplifier.inherit_context inherits the proof context (plus the
  5225 local bounds) of the current simplification process; any simproc
  5226 etc. that calls the Simplifier recursively should do this!  Removed
  5227 former Simplifier.inherit_bounds, which is already included here --
  5228 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  5229 specify an explicit context using Simplifier.context/theory_context.
  5230 
  5231 * Simplifier/Classical Reasoner: more abstract interfaces
  5232 change_simpset/claset for modifying the simpset/claset reference of a
  5233 theory; raw versions simpset/claset_ref etc. have been discontinued --
  5234 INCOMPATIBILITY.
  5235 
  5236 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  5237 "Trueprop" etc.
  5238 
  5239 
  5240 *** System ***
  5241 
  5242 * settings: the default heap location within ISABELLE_HOME_USER now
  5243 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  5244 Isabelle installations.
  5245 
  5246 * isabelle-process: option -S (secure mode) disables some critical
  5247 operations, notably runtime compilation and evaluation of ML source
  5248 code.
  5249 
  5250 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  5251 
  5252 * Support for parallel execution, using native multicore support of
  5253 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  5254 independent theories, according to the given theory header
  5255 specifications. The maximum number of worker threads is specified via
  5256 usedir option -M or the "max-threads" setting in Proof General. A
  5257 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  5258 to 6 on a 8-core machine.  User-code needs to observe certain
  5259 guidelines for thread-safe programming, see appendix A in the Isar
  5260 Implementation manual.
  5261 
  5262 
  5263 
  5264 New in Isabelle2005 (October 2005)
  5265 ----------------------------------
  5266 
  5267 *** General ***
  5268 
  5269 * Theory headers: the new header syntax for Isar theories is
  5270 
  5271   theory <name>
  5272   imports <theory1> ... <theoryN>
  5273   uses <file1> ... <fileM>
  5274   begin
  5275 
  5276 where the 'uses' part is optional.  The previous syntax
  5277 
  5278   theory <name> = <theory1> + ... + <theoryN>:
  5279 
  5280 will disappear in the next release.  Use isatool fixheaders to convert
  5281 existing theory files.  Note that there is no change in ancient
  5282 non-Isar theories now, but these will disappear soon.
  5283 
  5284 * Theory loader: parent theories can now also be referred to via
  5285 relative and absolute paths.
  5286 
  5287 * Command 'find_theorems' searches for a list of criteria instead of a
  5288 list of constants. Known criteria are: intro, elim, dest, name:string,
  5289 simp:term, and any term. Criteria can be preceded by '-' to select
  5290 theorems that do not match. Intro, elim, dest select theorems that
  5291 match the current goal, name:s selects theorems whose fully qualified
  5292 name contain s, and simp:term selects all simplification rules whose
  5293 lhs match term.  Any other term is interpreted as pattern and selects
  5294 all theorems matching the pattern. Available in ProofGeneral under
  5295 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  5296 
  5297   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  5298 
  5299 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  5300 matching the current goal as introduction rule and not having "HOL."
  5301 in their name (i.e. not being defined in theory HOL).
  5302 
  5303 * Command 'thms_containing' has been discontinued in favour of
  5304 'find_theorems'; INCOMPATIBILITY.
  5305 
  5306 * Communication with Proof General is now 8bit clean, which means that
  5307 Unicode text in UTF-8 encoding may be used within theory texts (both
  5308 formal and informal parts).  Cf. option -U of the Isabelle Proof
  5309 General interface.  Here are some simple examples (cf. src/HOL/ex):
  5310 
  5311   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  5312   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  5313 
  5314 * Improved efficiency of the Simplifier and, to a lesser degree, the
  5315 Classical Reasoner.  Typical big applications run around 2 times
  5316 faster.
  5317 
  5318 
  5319 *** Document preparation ***
  5320 
  5321 * Commands 'display_drafts' and 'print_drafts' perform simple output
  5322 of raw sources.  Only those symbols that do not require additional
  5323 LaTeX packages (depending on comments in isabellesym.sty) are
  5324 displayed properly, everything else is left verbatim.  isatool display
  5325 and isatool print are used as front ends (these are subject to the
  5326 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  5327 
  5328 * Command tags control specific markup of certain regions of text,
  5329 notably folding and hiding.  Predefined tags include "theory" (for
  5330 theory begin and end), "proof" for proof commands, and "ML" for
  5331 commands involving ML code; the additional tags "visible" and
  5332 "invisible" are unused by default.  Users may give explicit tag
  5333 specifications in the text, e.g. ''by %invisible (auto)''.  The
  5334 interpretation of tags is determined by the LaTeX job during document
  5335 preparation: see option -V of isatool usedir, or options -n and -t of
  5336 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  5337 \isadroptag.
  5338 
  5339 Several document versions may be produced at the same time via isatool
  5340 usedir (the generated index.html will link all of them).  Typical
  5341 specifications include ''-V document=theory,proof,ML'' to present
  5342 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  5343 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  5344 these parts without any formal replacement text.  The Isabelle site
  5345 default settings produce ''document'' and ''outline'' versions as
  5346 specified above.
  5347 
  5348 * Several new antiquotations:
  5349 
  5350   @{term_type term} prints a term with its type annotated;
  5351 
  5352   @{typeof term} prints the type of a term;
  5353 
  5354   @{const const} is the same as @{term const}, but checks that the
  5355   argument is a known logical constant;
  5356 
  5357   @{term_style style term} and @{thm_style style thm} print a term or
  5358   theorem applying a "style" to it
  5359 
  5360   @{ML text}
  5361 
  5362 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  5363 definitions, equations, inequations etc., 'concl' printing only the
  5364 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  5365 to print the specified premise.  TermStyle.add_style provides an ML
  5366 interface for introducing further styles.  See also the "LaTeX Sugar"
  5367 document practical applications.  The ML antiquotation prints
  5368 type-checked ML expressions verbatim.
  5369 
  5370 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  5371 and 'text' support optional locale specification '(in loc)', which
  5372 specifies the default context for interpreting antiquotations.  For
  5373 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  5374 
  5375 * Option 'locale=NAME' of antiquotations specifies an alternative
  5376 context interpreting the subsequent argument.  For example: @{thm
  5377 [locale=lattice] inf_assoc}.
  5378 
  5379 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  5380 a proof context.
  5381 
  5382 * Proper output of antiquotations for theory commands involving a
  5383 proof context (such as 'locale' or 'theorem (in loc) ...').
  5384 
  5385 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  5386 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  5387 
  5388 * isatool usedir: new option -C (default true) controls whether option
  5389 -D should include a copy of the original document directory; -C false
  5390 prevents unwanted effects such as copying of administrative CVS data.
  5391 
  5392 
  5393 *** Pure ***
  5394 
  5395 * Considerably improved version of 'constdefs' command.  Now performs
  5396 automatic type-inference of declared constants; additional support for
  5397 local structure declarations (cf. locales and HOL records), see also
  5398 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  5399 sequential dependencies of definitions within a single 'constdefs'
  5400 section; moreover, the declared name needs to be an identifier.  If
  5401 all fails, consider to fall back on 'consts' and 'defs' separately.
  5402 
  5403 * Improved indexed syntax and implicit structures.  First of all,
  5404 indexed syntax provides a notational device for subscripted
  5405 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  5406 expressions.  Secondly, in a local context with structure
  5407 declarations, number indexes \<^sub>n or the empty index (default
  5408 number 1) refer to a certain fixed variable implicitly; option
  5409 show_structs controls printing of implicit structures.  Typical
  5410 applications of these concepts involve record types and locales.
  5411 
  5412 * New command 'no_syntax' removes grammar declarations (and
  5413 translations) resulting from the given syntax specification, which is
  5414 interpreted in the same manner as for the 'syntax' command.
  5415 
  5416 * 'Advanced' translation functions (parse_translation etc.) may depend
  5417 on the signature of the theory context being presently used for
  5418 parsing/printing, see also isar-ref manual.
  5419 
  5420 * Improved 'oracle' command provides a type-safe interface to turn an
  5421 ML expression of type theory -> T -> term into a primitive rule of
  5422 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  5423 is already included here); see also FOL/ex/IffExample.thy;
  5424 INCOMPATIBILITY.
  5425 
  5426 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  5427 before); "cI" is no longer bound, use "c.intro" instead.
  5428 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  5429 axclasses vs. locales.
  5430 
  5431 * Improved internal renaming of symbolic identifiers -- attach primes
  5432 instead of base 26 numbers.
  5433 
  5434 * New flag show_question_marks controls printing of leading question
  5435 marks in schematic variable names.
  5436 
  5437 * In schematic variable names, *any* symbol following \<^isub> or
  5438 \<^isup> is now treated as part of the base name.  For example, the
  5439 following works without printing of awkward ".0" indexes:
  5440 
  5441   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  5442     by simp
  5443 
  5444 * Inner syntax includes (*(*nested*) comments*).
  5445 
  5446 * Pretty printer now supports unbreakable blocks, specified in mixfix
  5447 annotations as "(00...)".
  5448 
  5449 * Clear separation of logical types and nonterminals, where the latter
  5450 may only occur in 'syntax' specifications or type abbreviations.
  5451 Before that distinction was only partially implemented via type class
  5452 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  5453 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  5454 exotic syntax specifications may require further adaption
  5455 (e.g. Cube/Cube.thy).
  5456 
  5457 * Removed obsolete type class "logic", use the top sort {} instead.
  5458 Note that non-logical types should be declared as 'nonterminals'
  5459 rather than 'types'.  INCOMPATIBILITY for new object-logic
  5460 specifications.
  5461 
  5462 * Attributes 'induct' and 'cases': type or set names may now be
  5463 locally fixed variables as well.
  5464 
  5465 * Simplifier: can now control the depth to which conditional rewriting
  5466 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  5467 Limit.
  5468 
  5469 * Simplifier: simplification procedures may now take the current
  5470 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  5471 interface), which is very useful for calling the Simplifier
  5472 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  5473 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  5474 low-level mk_simproc no longer applies Logic.varify internally, to
  5475 allow for use in a context of fixed variables.
  5476 
  5477 * thin_tac now works even if the assumption being deleted contains !!
  5478 or ==>.  More generally, erule now works even if the major premise of
  5479 the elimination rule contains !! or ==>.
  5480 
  5481 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  5482 
  5483 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  5484 from Pure, which contains all common declarations already.  Both
  5485 theories are defined via plain Isabelle/Isar .thy files.
  5486 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  5487 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  5488 use isatool fixcpure to adapt your theory and ML sources.
  5489 
  5490 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  5491 selections of theorems in named facts via index ranges.
  5492 
  5493 * 'print_theorems': in theory mode, really print the difference
  5494 wrt. the last state (works for interactive theory development only),
  5495 in proof mode print all local facts (cf. 'print_facts');
  5496 
  5497 * 'hide': option '(open)' hides only base names.
  5498 
  5499 * More efficient treatment of intermediate checkpoints in interactive
  5500 theory development.
  5501 
  5502 * Code generator is now invoked via code_module (incremental code
  5503 generation) and code_library (modular code generation, ML structures
  5504 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  5505 must be quoted when used as identifiers.
  5506 
  5507 * New 'value' command for reading, evaluating and printing terms using
  5508 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  5509 quoted when used as identifier.
  5510 
  5511 
  5512 *** Locales ***
  5513 
  5514 * New commands for the interpretation of locale expressions in
  5515 theories (1), locales (2) and proof contexts (3).  These generate
  5516 proof obligations from the expression specification.  After the
  5517 obligations have been discharged, theorems of the expression are added
  5518 to the theory, target locale or proof context.  The synopsis of the
  5519 commands is a follows:
  5520 
  5521   (1) interpretation expr inst
  5522   (2) interpretation target < expr
  5523   (3) interpret expr inst
  5524 
  5525 Interpretation in theories and proof contexts require a parameter
  5526 instantiation of terms from the current context.  This is applied to
  5527 specifications and theorems of the interpreted expression.
  5528 Interpretation in locales only permits parameter renaming through the
  5529 locale expression.  Interpretation is smart in that interpretations
  5530 that are active already do not occur in proof obligations, neither are
  5531 instantiated theorems stored in duplicate.  Use 'print_interps' to
  5532 inspect active interpretations of a particular locale.  For details,
  5533 see the Isar Reference manual.  Examples can be found in
  5534 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  5535 
  5536 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  5537 'interpret' instead.
  5538 
  5539 * New context element 'constrains' for adding type constraints to
  5540 parameters.
  5541 
  5542 * Context expressions: renaming of parameters with syntax
  5543 redeclaration.
  5544 
  5545 * Locale declaration: 'includes' disallowed.
  5546 
  5547 * Proper static binding of attribute syntax -- i.e. types / terms /
  5548 facts mentioned as arguments are always those of the locale definition
  5549 context, independently of the context of later invocations.  Moreover,
  5550 locale operations (renaming and type / term instantiation) are applied
  5551 to attribute arguments as expected.
  5552 
  5553 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  5554 actual attributes; rare situations may require Attrib.attribute to
  5555 embed those attributes into Attrib.src that lack concrete syntax.
  5556 Attribute implementations need to cooperate properly with the static
  5557 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  5558 Attrib.XXX_thm etc. already do the right thing without further
  5559 intervention.  Only unusual applications -- such as "where" or "of"
  5560 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  5561 on the context and the facts involved -- may have to assign parsed
  5562 values to argument tokens explicitly.
  5563 
  5564 * Changed parameter management in theorem generation for long goal
  5565 statements with 'includes'.  INCOMPATIBILITY: produces a different
  5566 theorem statement in rare situations.
  5567 
  5568 * Locale inspection command 'print_locale' omits notes elements.  Use
  5569 'print_locale!' to have them included in the output.
  5570 
  5571 
  5572 *** Provers ***
  5573 
  5574 * Provers/hypsubst.ML: improved version of the subst method, for
  5575 single-step rewriting: it now works in bound variable contexts. New is
  5576 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  5577 rewrite a different subterm than the original subst method, which is
  5578 still available as 'simplesubst'.
  5579 
  5580 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  5581 and quasi orders.
  5582 
  5583 * Provers/trancl.ML: new transitivity reasoner for transitive and
  5584 reflexive-transitive closure of relations.
  5585 
  5586 * Provers/blast.ML: new reference depth_limit to make blast's depth
  5587 limit (previously hard-coded with a value of 20) user-definable.
  5588 
  5589 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  5590 is peformed already.  Object-logics merely need to finish their
  5591 initial simpset configuration as before.  INCOMPATIBILITY.
  5592 
  5593 
  5594 *** HOL ***
  5595 
  5596 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  5597 
  5598   syntax (epsilon)
  5599     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  5600 
  5601 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  5602 and x-symbol; use option '-m epsilon' to get it actually printed.
  5603 Moreover, the mathematically important symbolic identifier \<epsilon>
  5604 becomes available as variable, constant etc.  INCOMPATIBILITY,
  5605 
  5606 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  5607 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  5608 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  5609 support corresponding Isar calculations.
  5610 
  5611 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  5612 instead of ":".
  5613 
  5614 * theory SetInterval: changed the syntax for open intervals:
  5615 
  5616   Old       New
  5617   {..n(}    {..<n}
  5618   {)n..}    {n<..}
  5619   {m..n(}   {m..<n}
  5620   {)m..n}   {m<..n}
  5621   {)m..n(}  {m<..<n}
  5622 
  5623 The old syntax is still supported but will disappear in the next
  5624 release.  For conversion use the following Emacs search and replace
  5625 patterns (these are not perfect but work quite well):
  5626 
  5627   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  5628   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  5629 
  5630 * Theory Commutative_Ring (in Library): method comm_ring for proving
  5631 equalities in commutative rings; method 'algebra' provides a generic
  5632 interface.
  5633 
  5634 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5635 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5636 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5637 be a tuple pattern.
  5638 
  5639 Some new syntax forms are available:
  5640 
  5641   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5642   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5643   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5644   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5645 
  5646 The latter form "\<Sum>x < k. e" used to be based on a separate
  5647 function "Summation", which has been discontinued.
  5648 
  5649 * theory Finite_Set: in structured induction proofs, the insert case
  5650 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5651 (insert F x)'.
  5652 
  5653 * The 'refute' command has been extended to support a much larger
  5654 fragment of HOL, including axiomatic type classes, constdefs and
  5655 typedefs, inductive datatypes and recursion.
  5656 
  5657 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5658 Requires zChaff with proof generation to be installed.  See
  5659 HOL/ex/SAT_Examples.thy for examples.
  5660 
  5661 * Datatype induction via method 'induct' now preserves the name of the
  5662 induction variable. For example, when proving P(xs::'a list) by
  5663 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5664 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5665 in unstructured proof scripts.
  5666 
  5667 * Reworked implementation of records.  Improved scalability for
  5668 records with many fields, avoiding performance problems for type
  5669 inference. Records are no longer composed of nested field types, but
  5670 of nested extension types. Therefore the record type only grows linear
  5671 in the number of extensions and not in the number of fields.  The
  5672 top-level (users) view on records is preserved.  Potential
  5673 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5674 old record representation. The type generated for a record is called
  5675 <record_name>_ext_type.
  5676 
  5677 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5678 proofs triggered by a record definition or a simproc (if
  5679 quick_and_dirty is enabled).  Definitions of large records can take
  5680 quite long.
  5681 
  5682 New simproc record_upd_simproc for simplification of multiple record
  5683 updates enabled by default.  Moreover, trivial updates are also
  5684 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5685 occasionally, since simplification is more powerful by default.
  5686 
  5687 * typedef: proper support for polymorphic sets, which contain extra
  5688 type-variables in the term.
  5689 
  5690 * Simplifier: automatically reasons about transitivity chains
  5691 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5692 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5693 old proofs break occasionally as simplification may now solve more
  5694 goals than previously.
  5695 
  5696 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5697 present.  Works for all partial orders (class "order"), in particular
  5698 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5699 just like y <= x.
  5700 
  5701 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5702 bound variable or a constant then the let is unfolded.  Otherwise
  5703 first a is simplified to b, and then f b is simplified to g. If
  5704 possible we abstract b from g arriving at "let x = b in h x",
  5705 otherwise we unfold the let and arrive at g.  The simproc can be
  5706 enabled/disabled by the reference use_let_simproc.  Potential
  5707 INCOMPATIBILITY since simplification is more powerful by default.
  5708 
  5709 * Classical reasoning: the meson method now accepts theorems as arguments.
  5710 
  5711 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5712 jobs to provide advice on the provability of subgoals.
  5713 
  5714 * Theory OrderedGroup and Ring_and_Field: various additions and
  5715 improvements to faciliate calculations involving equalities and
  5716 inequalities.
  5717 
  5718 The following theorems have been eliminated or modified
  5719 (INCOMPATIBILITY):
  5720 
  5721   abs_eq             now named abs_of_nonneg
  5722   abs_of_ge_0        now named abs_of_nonneg
  5723   abs_minus_eq       now named abs_of_nonpos
  5724   imp_abs_id         now named abs_of_nonneg
  5725   imp_abs_neg_id     now named abs_of_nonpos
  5726   mult_pos           now named mult_pos_pos
  5727   mult_pos_le        now named mult_nonneg_nonneg
  5728   mult_pos_neg_le    now named mult_nonneg_nonpos
  5729   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5730   mult_neg           now named mult_neg_neg
  5731   mult_neg_le        now named mult_nonpos_nonpos
  5732 
  5733 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5734      
  5735      zero_le_square
  5736      not_square_less_zero 
  5737 
  5738   The following lemmas have been deleted from Real/RealPow:
  5739   
  5740      realpow_zero_zero
  5741      realpow_two
  5742      realpow_less
  5743      zero_le_power
  5744      realpow_two_le
  5745      abs_realpow_two
  5746      realpow_two_abs     
  5747 
  5748 * Theory Parity: added rules for simplifying exponents.
  5749 
  5750 * Theory List:
  5751 
  5752 The following theorems have been eliminated or modified
  5753 (INCOMPATIBILITY):
  5754 
  5755   list_all_Nil       now named list_all.simps(1)
  5756   list_all_Cons      now named list_all.simps(2)
  5757   list_all_conv      now named list_all_iff
  5758   set_mem_eq         now named mem_iff
  5759 
  5760 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5761 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5762 
  5763 
  5764 *** HOL-Complex ***
  5765 
  5766 * Theory RealDef: better support for embedding natural numbers and
  5767 integers in the reals.
  5768 
  5769 The following theorems have been eliminated or modified
  5770 (INCOMPATIBILITY):
  5771 
  5772   exp_ge_add_one_self  now requires no hypotheses
  5773   real_of_int_add      reversed direction of equality (use [symmetric])
  5774   real_of_int_minus    reversed direction of equality (use [symmetric])
  5775   real_of_int_diff     reversed direction of equality (use [symmetric])
  5776   real_of_int_mult     reversed direction of equality (use [symmetric])
  5777 
  5778 * Theory RComplete: expanded support for floor and ceiling functions.
  5779 
  5780 * Theory Ln is new, with properties of the natural logarithm
  5781 
  5782 * Hyperreal: There is a new type constructor "star" for making
  5783 nonstandard types.  The old type names are now type synonyms:
  5784 
  5785   hypreal = real star
  5786   hypnat = nat star
  5787   hcomplex = complex star
  5788 
  5789 * Hyperreal: Many groups of similarly-defined constants have been
  5790 replaced by polymorphic versions (INCOMPATIBILITY):
  5791 
  5792   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5793 
  5794   starset      <-- starsetNat, starsetC
  5795   *s*          <-- *sNat*, *sc*
  5796   starset_n    <-- starsetNat_n, starsetC_n
  5797   *sn*         <-- *sNatn*, *scn*
  5798   InternalSets <-- InternalNatSets, InternalCSets
  5799 
  5800   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5801   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5802   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5803   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5804   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5805 
  5806 * Hyperreal: Many type-specific theorems have been removed in favor of
  5807 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5808 
  5809   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5810   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5811   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5812   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5813   right_minus <-- hypreal_add_minus
  5814   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5815   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5816   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5817   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5818   mult_1_right <-- hcomplex_mult_one_right
  5819   mult_zero_left <-- hcomplex_mult_zero_left
  5820   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5821   right_distrib <-- hypnat_add_mult_distrib2
  5822   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5823   right_inverse <-- hypreal_mult_inverse
  5824   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5825   order_refl <-- {hypreal,hypnat}_le_refl
  5826   order_trans <-- {hypreal,hypnat}_le_trans
  5827   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5828   order_less_le <-- {hypreal,hypnat}_less_le
  5829   linorder_linear <-- {hypreal,hypnat}_le_linear
  5830   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5831   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5832   add_nonneg_nonneg <-- hypreal_le_add_order
  5833 
  5834 * Hyperreal: Separate theorems having to do with type-specific
  5835 versions of constants have been merged into theorems that apply to the
  5836 new polymorphic constants (INCOMPATIBILITY):
  5837 
  5838   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5839   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5840   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5841   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5842   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5843   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5844   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5845   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5846   STAR_diff <-- {STAR,STARC}_diff
  5847   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5848     STARC_hcomplex_of_complex}_image_subset
  5849   starset_n_Un <-- starset{Nat,C}_n_Un
  5850   starset_n_Int <-- starset{Nat,C}_n_Int
  5851   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5852   starset_n_diff <-- starset{Nat,C}_n_diff
  5853   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5854   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5855   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5856   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5857   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5858   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5859   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5860   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5861   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5862   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5863   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5864   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5865   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5866   starfun_diff <-- starfun{C,RC,CR}_diff
  5867   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5868   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5869   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5870   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5871   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5872   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5873   starfun_Id <-- starfunC_Id
  5874   starfun_approx <-- starfun{Nat,CR}_approx
  5875   starfun_capprox <-- starfun{C,RC}_capprox
  5876   starfun_abs <-- starfunNat_rabs
  5877   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5878   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5879   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5880   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5881   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5882   starfun_add_approx <-- starfunCR_add_approx
  5883   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5884   starfun_divide <-- starfun{C,CR,RC}_divide
  5885   starfun_n <-- starfun{Nat,C}_n
  5886   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5887   starfun_n_add <-- starfun{Nat,C}_n_add
  5888   starfun_n_add_minus <-- starfunNat_n_add_minus
  5889   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5890   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5891   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5892 
  5893   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5894   star_n_minus <-- {hypreal,hcomplex}_minus
  5895   star_n_diff <-- {hypreal,hcomplex}_diff
  5896   star_n_mult <-- {hypreal,hcomplex}_mult
  5897   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5898   star_n_le <-- {hypreal,hypnat}_le
  5899   star_n_less <-- {hypreal,hypnat}_less
  5900   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5901   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5902   star_n_abs <-- hypreal_hrabs
  5903   star_n_divide <-- hcomplex_divide
  5904 
  5905   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5906   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5907   star_of_diff <-- hypreal_of_real_diff
  5908   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5909   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5910   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5911   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5912   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5913   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5914   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5915   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5916   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5917   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5918   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5919   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5920   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5921   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5922   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5923   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5924   star_of_power <-- hypreal_of_real_power
  5925   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5926 
  5927 * Hyperreal: new method "transfer" that implements the transfer
  5928 principle of nonstandard analysis. With a subgoal that mentions
  5929 nonstandard types like "'a star", the command "apply transfer"
  5930 replaces it with an equivalent one that mentions only standard types.
  5931 To be successful, all free variables must have standard types; non-
  5932 standard variables must have explicit universal quantifiers.
  5933 
  5934 * Hyperreal: A theory of Taylor series.
  5935 
  5936 
  5937 *** HOLCF ***
  5938 
  5939 * Discontinued special version of 'constdefs' (which used to support
  5940 continuous functions) in favor of the general Pure one with full
  5941 type-inference.
  5942 
  5943 * New simplification procedure for solving continuity conditions; it
  5944 is much faster on terms with many nested lambda abstractions (cubic
  5945 instead of exponential time).
  5946 
  5947 * New syntax for domain package: selector names are now optional.
  5948 Parentheses should be omitted unless argument is lazy, for example:
  5949 
  5950   domain 'a stream = cons "'a" (lazy "'a stream")
  5951 
  5952 * New command 'fixrec' for defining recursive functions with pattern
  5953 matching; defining multiple functions with mutual recursion is also
  5954 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5955 sinr, or any data constructor defined by the domain package. The given
  5956 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5957 syntax and examples.
  5958 
  5959 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5960 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5961 but the proof obligation additionally includes an admissibility
  5962 requirement. The packages generate instances of class cpo or pcpo,
  5963 with continuity and strictness theorems for Rep and Abs.
  5964 
  5965 * HOLCF: Many theorems have been renamed according to a more standard naming
  5966 scheme (INCOMPATIBILITY):
  5967 
  5968   foo_inject:  "foo$x = foo$y ==> x = y"
  5969   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5970   foo_less:    "(foo$x << foo$y) = (x << y)"
  5971   foo_strict:  "foo$UU = UU"
  5972   foo_defined: "... ==> foo$x ~= UU"
  5973   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5974 
  5975 
  5976 *** ZF ***
  5977 
  5978 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5979 including the First Isomorphism Theorem (on quotienting by the kernel
  5980 of a homomorphism).
  5981 
  5982 * ZF/Simplifier: install second copy of type solver that actually
  5983 makes use of TC rules declared to Isar proof contexts (or locales);
  5984 the old version is still required for ML proof scripts.
  5985 
  5986 
  5987 *** Cube ***
  5988 
  5989 * Converted to Isar theory format; use locales instead of axiomatic
  5990 theories.
  5991 
  5992 
  5993 *** ML ***
  5994 
  5995 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5996 for ||>, ||>>, |>>,
  5997 
  5998 * Pure/library.ML no longer defines its own option datatype, but uses
  5999 that of the SML basis, which has constructors NONE and SOME instead of
  6000 None and Some, as well as exception Option.Option instead of OPTION.
  6001 The functions the, if_none, is_some, is_none have been adapted
  6002 accordingly, while Option.map replaces apsome.
  6003 
  6004 * Pure/library.ML: the exception LIST has been given up in favour of
  6005 the standard exceptions Empty and Subscript, as well as
  6006 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  6007 superceded by the standard hd and tl functions etc.
  6008 
  6009 A number of basic list functions are no longer exported to the ML
  6010 toplevel, as they are variants of predefined functions.  The following
  6011 suggests how one can translate existing code:
  6012 
  6013     rev_append xs ys = List.revAppend (xs, ys)
  6014     nth_elem (i, xs) = List.nth (xs, i)
  6015     last_elem xs = List.last xs
  6016     flat xss = List.concat xss
  6017     seq fs = List.app fs
  6018     partition P xs = List.partition P xs
  6019     mapfilter f xs = List.mapPartial f xs
  6020 
  6021 * Pure/library.ML: several combinators for linear functional
  6022 transformations, notably reverse application and composition:
  6023 
  6024   x |> f                f #> g
  6025   (x, y) |-> f          f #-> g
  6026 
  6027 * Pure/library.ML: introduced/changed precedence of infix operators:
  6028 
  6029   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  6030   infix 2 ?;
  6031   infix 3 o oo ooo oooo;
  6032   infix 4 ~~ upto downto;
  6033 
  6034 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  6035 infix operators.
  6036 
  6037 * Pure/library.ML: natural list combinators fold, fold_rev, and
  6038 fold_map support linear functional transformations and nesting.  For
  6039 example:
  6040 
  6041   fold f [x1, ..., xN] y =
  6042     y |> f x1 |> ... |> f xN
  6043 
  6044   (fold o fold) f [xs1, ..., xsN] y =
  6045     y |> fold f xs1 |> ... |> fold f xsN
  6046 
  6047   fold f [x1, ..., xN] =
  6048     f x1 #> ... #> f xN
  6049 
  6050   (fold o fold) f [xs1, ..., xsN] =
  6051     fold f xs1 #> ... #> fold f xsN
  6052 
  6053 * Pure/library.ML: the following selectors on type 'a option are
  6054 available:
  6055 
  6056   the:               'a option -> 'a  (*partial*)
  6057   these:             'a option -> 'a  where 'a = 'b list
  6058   the_default: 'a -> 'a option -> 'a
  6059   the_list:          'a option -> 'a list
  6060 
  6061 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  6062 basic operations for association lists, following natural argument
  6063 order; moreover the explicit equality predicate passed here avoids
  6064 potentially expensive polymorphic runtime equality checks.
  6065 The old functions may be expressed as follows:
  6066 
  6067   assoc = uncurry (AList.lookup (op =))
  6068   assocs = these oo AList.lookup (op =)
  6069   overwrite = uncurry (AList.update (op =)) o swap
  6070 
  6071 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  6072 
  6073   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  6074   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  6075 
  6076 replacing make_keylist and keyfilter (occassionally used)
  6077 Naive rewrites:
  6078 
  6079   make_keylist = AList.make
  6080   keyfilter = AList.find (op =)
  6081 
  6082 * eq_fst and eq_snd now take explicit equality parameter, thus
  6083   avoiding eqtypes. Naive rewrites:
  6084 
  6085     eq_fst = eq_fst (op =)
  6086     eq_snd = eq_snd (op =)
  6087 
  6088 * Removed deprecated apl and apr (rarely used).
  6089   Naive rewrites:
  6090 
  6091     apl (n, op) =>>= curry op n
  6092     apr (op, m) =>>= fn n => op (n, m)
  6093 
  6094 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  6095 provides a reasonably efficient light-weight implementation of sets as
  6096 lists.
  6097 
  6098 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  6099 few new operations; existing lookup and update are now curried to
  6100 follow natural argument order (for use with fold etc.);
  6101 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  6102 
  6103 * Pure/General: output via the Isabelle channels of
  6104 writeln/warning/error etc. is now passed through Output.output, with a
  6105 hook for arbitrary transformations depending on the print_mode
  6106 (cf. Output.add_mode -- the first active mode that provides a output
  6107 function wins).  Already formatted output may be embedded into further
  6108 text via Output.raw; the result of Pretty.string_of/str_of and derived
  6109 functions (string_of_term/cterm/thm etc.) is already marked raw to
  6110 accommodate easy composition of diagnostic messages etc.  Programmers
  6111 rarely need to care about Output.output or Output.raw at all, with
  6112 some notable exceptions: Output.output is required when bypassing the
  6113 standard channels (writeln etc.), or in token translations to produce
  6114 properly formatted results; Output.raw is required when capturing
  6115 already output material that will eventually be presented to the user
  6116 a second time.  For the default print mode, both Output.output and
  6117 Output.raw have no effect.
  6118 
  6119 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  6120 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  6121 cumulative results are displayed at the end of a batch session.
  6122 
  6123 * Pure/General: File.sysify_path and File.quote_sysify path have been
  6124 replaced by File.platform_path and File.shell_path (with appropriate
  6125 hooks).  This provides a clean interface for unusual systems where the
  6126 internal and external process view of file names are different.
  6127 
  6128 * Pure: more efficient orders for basic syntactic entities: added
  6129 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  6130 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  6131 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  6132 orders now -- potential INCOMPATIBILITY for code that depends on a
  6133 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  6134 Library.sort_strings on result).
  6135 
  6136 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  6137 fold_types traverse types/terms from left to right, observing natural
  6138 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  6139 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  6140 
  6141 * Pure: name spaces have been refined, with significant changes of the
  6142 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  6143 to extern(_table).  The plain name entry path is superceded by a
  6144 general 'naming' context, which also includes the 'policy' to produce
  6145 a fully qualified name and external accesses of a fully qualified
  6146 name; NameSpace.extend is superceded by context dependent
  6147 Sign.declare_name.  Several theory and proof context operations modify
  6148 the naming context.  Especially note Theory.restore_naming and
  6149 ProofContext.restore_naming to get back to a sane state; note that
  6150 Theory.add_path is no longer sufficient to recover from
  6151 Theory.absolute_path in particular.
  6152 
  6153 * Pure: new flags short_names (default false) and unique_names
  6154 (default true) for controlling output of qualified names.  If
  6155 short_names is set, names are printed unqualified.  If unique_names is
  6156 reset, the name prefix is reduced to the minimum required to achieve
  6157 the original result when interning again, even if there is an overlap
  6158 with earlier declarations.
  6159 
  6160 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  6161 now 'extend', and 'merge' gets an additional Pretty.pp argument
  6162 (useful for printing error messages).  INCOMPATIBILITY.
  6163 
  6164 * Pure: major reorganization of the theory context.  Type Sign.sg and
  6165 Theory.theory are now identified, referring to the universal
  6166 Context.theory (see Pure/context.ML).  Actual signature and theory
  6167 content is managed as theory data.  The old code and interfaces were
  6168 spread over many files and structures; the new arrangement introduces
  6169 considerable INCOMPATIBILITY to gain more clarity:
  6170 
  6171   Context -- theory management operations (name, identity, inclusion,
  6172     parents, ancestors, merge, etc.), plus generic theory data;
  6173 
  6174   Sign -- logical signature and syntax operations (declaring consts,
  6175     types, etc.), plus certify/read for common entities;
  6176 
  6177   Theory -- logical theory operations (stating axioms, definitions,
  6178     oracles), plus a copy of logical signature operations (consts,
  6179     types, etc.); also a few basic management operations (Theory.copy,
  6180     Theory.merge, etc.)
  6181 
  6182 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  6183 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  6184 for convenience -- they merely return the theory.
  6185 
  6186 * Pure: type Type.tsig is superceded by theory in most interfaces.
  6187 
  6188 * Pure: the Isar proof context type is already defined early in Pure
  6189 as Context.proof (note that ProofContext.context and Proof.context are
  6190 aliases, where the latter is the preferred name).  This enables other
  6191 Isabelle components to refer to that type even before Isar is present.
  6192 
  6193 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  6194 typeK, constK, axiomK, oracleK), but provide explicit operations for
  6195 any of these kinds.  For example, Sign.intern typeK is now
  6196 Sign.intern_type, Theory.hide_space Sign.typeK is now
  6197 Theory.hide_types.  Also note that former
  6198 Theory.hide_classes/types/consts are now
  6199 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  6200 internalize their arguments!  INCOMPATIBILITY.
  6201 
  6202 * Pure: get_thm interface (of PureThy and ProofContext) expects
  6203 datatype thmref (with constructors Name and NameSelection) instead of
  6204 plain string -- INCOMPATIBILITY;
  6205 
  6206 * Pure: cases produced by proof methods specify options, where NONE
  6207 means to remove case bindings -- INCOMPATIBILITY in
  6208 (RAW_)METHOD_CASES.
  6209 
  6210 * Pure: the following operations retrieve axioms or theorems from a
  6211 theory node or theory hierarchy, respectively:
  6212 
  6213   Theory.axioms_of: theory -> (string * term) list
  6214   Theory.all_axioms_of: theory -> (string * term) list
  6215   PureThy.thms_of: theory -> (string * thm) list
  6216   PureThy.all_thms_of: theory -> (string * thm) list
  6217 
  6218 * Pure: print_tac now outputs the goal through the trace channel.
  6219 
  6220 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  6221 Reference Toplevel.debug (default false) controls detailed printing
  6222 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  6223 controls execution profiling -- set to 1 for time and 2 for space
  6224 (both increase the runtime).
  6225 
  6226 * Isar session: The initial use of ROOT.ML is now always timed,
  6227 i.e. the log will show the actual process times, in contrast to the
  6228 elapsed wall-clock time that the outer shell wrapper produces.
  6229 
  6230 * Simplifier: improved handling of bound variables (nameless
  6231 representation, avoid allocating new strings).  Simprocs that invoke
  6232 the Simplifier recursively should use Simplifier.inherit_bounds to
  6233 avoid local name clashes.  Failure to do so produces warnings
  6234 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  6235 for further details.
  6236 
  6237 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  6238 bindings for all theorems stored within a given theory; this may help
  6239 in porting non-Isar theories to Isar ones, while keeping ML proof
  6240 scripts for the time being.
  6241 
  6242 * ML operator HTML.with_charset specifies the charset begin used for
  6243 generated HTML files.  For example:
  6244 
  6245   HTML.with_charset "utf-8" use_thy "Hebrew";
  6246   HTML.with_charset "utf-8" use_thy "Chinese";
  6247 
  6248 
  6249 *** System ***
  6250 
  6251 * Allow symlinks to all proper Isabelle executables (Isabelle,
  6252 isabelle, isatool etc.).
  6253 
  6254 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  6255 isatool doc, isatool mkdir, display_drafts etc.).
  6256 
  6257 * isatool usedir: option -f allows specification of the ML file to be
  6258 used by Isabelle; default is ROOT.ML.
  6259 
  6260 * New isatool version outputs the version identifier of the Isabelle
  6261 distribution being used.
  6262 
  6263 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  6264 (containing Boolean satisfiability problems) into Isabelle/HOL
  6265 theories.
  6266 
  6267 
  6268 
  6269 New in Isabelle2004 (April 2004)
  6270 --------------------------------
  6271 
  6272 *** General ***
  6273 
  6274 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  6275   Replaces linorder.ML.
  6276 
  6277 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  6278   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  6279   (\<a>...\<z>), are now considered normal letters, and can therefore
  6280   be used anywhere where an ASCII letter (a...zA...Z) has until
  6281   now. COMPATIBILITY: This obviously changes the parsing of some
  6282   terms, especially where a symbol has been used as a binder, say
  6283   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  6284   as an identifier.  Fix it by inserting a space around former
  6285   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  6286   existing theory and ML files.
  6287 
  6288 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  6289 
  6290 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  6291   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  6292   a normal (but invisible) letter. For multiple letter subscripts repeat
  6293   \<^isub> like this: x\<^isub>1\<^isub>2.
  6294 
  6295 * Pure: There are now sub-/superscripts that can span more than one
  6296   character. Text between \<^bsub> and \<^esub> is set in subscript in
  6297   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  6298   superscript. The new control characters are not identifier parts.
  6299 
  6300 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  6301   content of "..." to the latex file instead of \isacntrl... . The "..."
  6302   may consist of any printable characters excluding the end bracket >.
  6303 
  6304 * Pure: Using new Isar command "finalconsts" (or the ML functions
  6305   Theory.add_finals or Theory.add_finals_i) it is now possible to
  6306   declare constants "final", which prevents their being given a definition
  6307   later.  It is useful for constants whose behaviour is fixed axiomatically
  6308   rather than definitionally, such as the meta-logic connectives.
  6309 
  6310 * Pure: 'instance' now handles general arities with general sorts
  6311   (i.e. intersections of classes),
  6312 
  6313 * Presentation: generated HTML now uses a CSS style sheet to make layout
  6314   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  6315   It can be changed to alter the colors/layout of generated pages.
  6316 
  6317 
  6318 *** Isar ***
  6319 
  6320 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  6321   cut_tac, subgoal_tac and thin_tac:
  6322   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  6323     locales are no longer forced to write Isar proof scripts.
  6324     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  6325     emulations.
  6326   - INCOMPATIBILITY: names of variables to be instantiated may no
  6327     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  6328     This is consistent with the instantiation attribute "where".
  6329 
  6330 * Attributes "where" and "of":
  6331   - Now take type variables of instantiated theorem into account when reading
  6332     the instantiation string.  This fixes a bug that caused instantiated
  6333     theorems to have too special types in some circumstances.
  6334   - "where" permits explicit instantiations of type variables.
  6335 
  6336 * Calculation commands "moreover" and "also" no longer interfere with
  6337   current facts ("this"), admitting arbitrary combinations with "then"
  6338   and derived forms.
  6339 
  6340 * Locales:
  6341   - Goal statements involving the context element "includes" no longer
  6342     generate theorems with internal delta predicates (those ending on
  6343     "_axioms") in the premise.
  6344     Resolve particular premise with <locale>.intro to obtain old form.
  6345   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  6346     specification and "includes" elements in goal statement.
  6347   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  6348     [intro?] and [elim?] (respectively) by default.
  6349   - Experimental command for instantiation of locales in proof contexts:
  6350         instantiate <label>[<attrs>]: <loc>
  6351     Instantiates locale <loc> and adds all its theorems to the current context
  6352     taking into account their attributes.  Label and attrs are optional
  6353     modifiers, like in theorem declarations.  If present, names of
  6354     instantiated theorems are qualified with <label>, and the attributes
  6355     <attrs> are applied after any attributes these theorems might have already.
  6356       If the locale has assumptions, a chained fact of the form
  6357     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  6358     are derived.  The command does not support old-style locales declared
  6359     with "locale (open)".
  6360       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  6361 
  6362 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  6363   (Isar) contexts.
  6364 
  6365 
  6366 *** HOL ***
  6367 
  6368 * Proof import: new image HOL4 contains the imported library from
  6369   the HOL4 system with about 2500 theorems. It is imported by
  6370   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  6371   can be used like any other Isabelle image.  See
  6372   HOL/Import/HOL/README for more information.
  6373 
  6374 * Simplifier:
  6375   - Much improved handling of linear and partial orders.
  6376     Reasoners for linear and partial orders are set up for type classes
  6377     "linorder" and "order" respectively, and are added to the default simpset
  6378     as solvers.  This means that the simplifier can build transitivity chains
  6379     to solve goals from the assumptions.
  6380   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  6381     of blast or auto after simplification become unnecessary because the goal
  6382     is solved by simplification already.
  6383 
  6384 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  6385     all proved in axiomatic type classes for semirings, rings and fields.
  6386 
  6387 * Numerics:
  6388   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  6389     now formalized using the Ring_and_Field theory mentioned above.
  6390   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  6391     than before, because now they are set up once in a generic manner.
  6392   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  6393     Look for the general versions in Ring_and_Field (and Power if they concern
  6394     exponentiation).
  6395 
  6396 * Type "rat" of the rational numbers is now available in HOL-Complex.
  6397 
  6398 * Records:
  6399   - Record types are now by default printed with their type abbreviation
  6400     instead of the list of all field types. This can be configured via
  6401     the reference "print_record_type_abbr".
  6402   - Simproc "record_upd_simproc" for simplification of multiple updates added
  6403     (not enabled by default).
  6404   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  6405     EX x. x = sel r to True (not enabled by default).
  6406   - Tactic "record_split_simp_tac" to split and simplify records added.
  6407 
  6408 * 'specification' command added, allowing for definition by
  6409   specification.  There is also an 'ax_specification' command that
  6410   introduces the new constants axiomatically.
  6411 
  6412 * arith(_tac) is now able to generate counterexamples for reals as well.
  6413 
  6414 * HOL-Algebra: new locale "ring" for non-commutative rings.
  6415 
  6416 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  6417   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  6418 
  6419 * HOL-Matrix: a first theory for matrices in HOL with an application of
  6420   matrix theory to linear programming.
  6421 
  6422 * Unions and Intersections:
  6423   The latex output syntax of UN and INT has been changed
  6424   from "\Union x \in A. B" to "\Union_{x \in A} B"
  6425   i.e. the index formulae has become a subscript.
  6426   Similarly for "\Union x. B", and for \Inter instead of \Union.
  6427 
  6428 * Unions and Intersections over Intervals:
  6429   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  6430   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  6431   like in normal math, and corresponding versions for < and for intersection.
  6432 
  6433 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  6434   lexicographic dictonary ordering has been added as "lexord".
  6435 
  6436 * ML: the legacy theory structures Int and List have been removed. They had
  6437   conflicted with ML Basis Library structures having the same names.
  6438 
  6439 * 'refute' command added to search for (finite) countermodels.  Only works
  6440   for a fragment of HOL.  The installation of an external SAT solver is
  6441   highly recommended.  See "HOL/Refute.thy" for details.
  6442 
  6443 * 'quickcheck' command: Allows to find counterexamples by evaluating
  6444   formulae under an assignment of free variables to random values.
  6445   In contrast to 'refute', it can deal with inductive datatypes,
  6446   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  6447   for examples.
  6448 
  6449 
  6450 *** HOLCF ***
  6451 
  6452 * Streams now come with concatenation and are part of the HOLCF image
  6453 
  6454 
  6455 
  6456 New in Isabelle2003 (May 2003)
  6457 ------------------------------
  6458 
  6459 *** General ***
  6460 
  6461 * Provers/simplifier:
  6462 
  6463   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  6464     Assumptions are now subject to complete mutual simplification,
  6465     not just from left to right. The simplifier now preserves
  6466     the order of assumptions.
  6467 
  6468     Potential INCOMPATIBILITY:
  6469 
  6470     -- simp sometimes diverges where the old version did
  6471        not, e.g. invoking simp on the goal
  6472 
  6473         [| P (f x); y = x; f x = f y |] ==> Q
  6474 
  6475        now gives rise to the infinite reduction sequence
  6476 
  6477         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  6478 
  6479        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  6480        kind of problem.
  6481 
  6482     -- Tactics combining classical reasoner and simplification (such as auto)
  6483        are also affected by this change, because many of them rely on
  6484        simp. They may sometimes diverge as well or yield a different numbers
  6485        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  6486        in case of problems. Sometimes subsequent calls to the classical
  6487        reasoner will fail because a preceeding call to the simplifier too
  6488        eagerly simplified the goal, e.g. deleted redundant premises.
  6489 
  6490   - The simplifier trace now shows the names of the applied rewrite rules
  6491 
  6492   - You can limit the number of recursive invocations of the simplifier
  6493     during conditional rewriting (where the simplifie tries to solve the
  6494     conditions before applying the rewrite rule):
  6495     ML "simp_depth_limit := n"
  6496     where n is an integer. Thus you can force termination where previously
  6497     the simplifier would diverge.
  6498 
  6499   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  6500 
  6501   - No longer aborts on failed congruence proof.  Instead, the
  6502     congruence is ignored.
  6503 
  6504 * Pure: New generic framework for extracting programs from constructive
  6505   proofs. See HOL/Extraction.thy for an example instantiation, as well
  6506   as HOL/Extraction for some case studies.
  6507 
  6508 * Pure: The main goal of the proof state is no longer shown by default, only
  6509 the subgoals. This behaviour is controlled by a new flag.
  6510    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  6511 (ML: Proof.show_main_goal).
  6512 
  6513 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  6514 rules whose conclusion matches subgoal 1:
  6515       PG menu: Isabelle/Isar -> Show me -> matching rules
  6516 The rules are ordered by how closely they match the subgoal.
  6517 In particular, rules that solve a subgoal outright are displayed first
  6518 (or rather last, the way they are printed).
  6519 (ML: ProofGeneral.print_intros())
  6520 
  6521 * Pure: New flag trace_unify_fail causes unification to print
  6522 diagnostic information (PG: in trace buffer) when it fails. This is
  6523 useful for figuring out why single step proofs like rule, erule or
  6524 assumption failed.
  6525 
  6526 * Pure: Locale specifications now produce predicate definitions
  6527 according to the body of text (covering assumptions modulo local
  6528 definitions); predicate "loc_axioms" covers newly introduced text,
  6529 while "loc" is cumulative wrt. all included locale expressions; the
  6530 latter view is presented only on export into the global theory
  6531 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  6532 on the old view without predicates;
  6533 
  6534 * Pure: predefined locales "var" and "struct" are useful for sharing
  6535 parameters (as in CASL, for example); just specify something like
  6536 ``var x + var y + struct M'' as import;
  6537 
  6538 * Pure: improved thms_containing: proper indexing of facts instead of
  6539 raw theorems; check validity of results wrt. current name space;
  6540 include local facts of proof configuration (also covers active
  6541 locales), cover fixed variables in index; may use "_" in term
  6542 specification; an optional limit for the number of printed facts may
  6543 be given (the default is 40);
  6544 
  6545 * Pure: disallow duplicate fact bindings within new-style theory files
  6546 (batch-mode only);
  6547 
  6548 * Provers: improved induct method: assumptions introduced by case
  6549 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  6550 the goal statement); "foo" still refers to all facts collectively;
  6551 
  6552 * Provers: the function blast.overloaded has been removed: all constants
  6553 are regarded as potentially overloaded, which improves robustness in exchange
  6554 for slight decrease in efficiency;
  6555 
  6556 * Provers/linorder: New generic prover for transitivity reasoning over
  6557 linear orders.  Note: this prover is not efficient!
  6558 
  6559 * Isar: preview of problems to finish 'show' now produce an error
  6560 rather than just a warning (in interactive mode);
  6561 
  6562 
  6563 *** HOL ***
  6564 
  6565 * arith(_tac)
  6566 
  6567  - Produces a counter example if it cannot prove a goal.
  6568    Note that the counter example may be spurious if the goal is not a formula
  6569    of quantifier-free linear arithmetic.
  6570    In ProofGeneral the counter example appears in the trace buffer.
  6571 
  6572  - Knows about div k and mod k where k is a numeral of type nat or int.
  6573 
  6574  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  6575    linear arithmetic fails. This takes account of quantifiers and divisibility.
  6576    Presburger arithmetic can also be called explicitly via presburger(_tac).
  6577 
  6578 * simp's arithmetic capabilities have been enhanced a bit: it now
  6579 takes ~= in premises into account (by performing a case split);
  6580 
  6581 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  6582 are distributed over a sum of terms;
  6583 
  6584 * New tactic "trans_tac" and method "trans" instantiate
  6585 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  6586 "<=", "<" and "=").
  6587 
  6588 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  6589 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  6590 
  6591 * 'typedef' command has new option "open" to suppress the set
  6592 definition;
  6593 
  6594 * functions Min and Max on finite sets have been introduced (theory
  6595 Finite_Set);
  6596 
  6597 * attribute [symmetric] now works for relations as well; it turns
  6598 (x,y) : R^-1 into (y,x) : R, and vice versa;
  6599 
  6600 * induct over a !!-quantified statement (say !!x1..xn):
  6601   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  6602 
  6603 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  6604 %x. None. Warning: empty_def now refers to the previously hidden definition
  6605 of the empty set.
  6606 
  6607 * Algebra: formalization of classical algebra.  Intended as base for
  6608 any algebraic development in Isabelle.  Currently covers group theory
  6609 (up to Sylow's theorem) and ring theory (Universal Property of
  6610 Univariate Polynomials).  Contributions welcome;
  6611 
  6612 * GroupTheory: deleted, since its material has been moved to Algebra;
  6613 
  6614 * Complex: new directory of the complex numbers with numeric constants,
  6615 nonstandard complex numbers, and some complex analysis, standard and
  6616 nonstandard (Jacques Fleuriot);
  6617 
  6618 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  6619 
  6620 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  6621 Fleuriot);
  6622 
  6623 * Real/HahnBanach: updated and adapted to locales;
  6624 
  6625 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  6626 Gray and Kramer);
  6627 
  6628 * UNITY: added the Meier-Sanders theory of progress sets;
  6629 
  6630 * MicroJava: bytecode verifier and lightweight bytecode verifier
  6631 as abstract algorithms, instantiated to the JVM;
  6632 
  6633 * Bali: Java source language formalization. Type system, operational
  6634 semantics, axiomatic semantics. Supported language features:
  6635 classes, interfaces, objects,virtual methods, static methods,
  6636 static/instance fields, arrays, access modifiers, definite
  6637 assignment, exceptions.
  6638 
  6639 
  6640 *** ZF ***
  6641 
  6642 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6643 universe, etc.);
  6644 
  6645 * Main ZF: virtually all theories converted to new-style format;
  6646 
  6647 
  6648 *** ML ***
  6649 
  6650 * Pure: Tactic.prove provides sane interface for internal proofs;
  6651 omits the infamous "standard" operation, so this is more appropriate
  6652 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6653 
  6654 * Pure: improved error reporting of simprocs;
  6655 
  6656 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6657 up simprocs;
  6658 
  6659 
  6660 *** Document preparation ***
  6661 
  6662 * uses \par instead of \\ for line breaks in theory text. This may
  6663 shift some page breaks in large documents. To get the old behaviour
  6664 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6665 
  6666 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6667 other packages
  6668 
  6669 * \<euro> now needs package babel/greek instead of marvosym (which
  6670 broke \Rightarrow)
  6671 
  6672 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6673 textcomp package)
  6674 
  6675 
  6676 
  6677 New in Isabelle2002 (March 2002)
  6678 --------------------------------
  6679 
  6680 *** Document preparation ***
  6681 
  6682 * greatly simplified document preparation setup, including more
  6683 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6684 instructive isatool mkdir; users should basically be able to get
  6685 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6686 users may run a separate document processing stage manually like this:
  6687 "isatool usedir -D output HOL Test && isatool document Test/output";
  6688 
  6689 * theory dependency graph may now be incorporated into documents;
  6690 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6691 with \includegraphics of LaTeX;
  6692 
  6693 * proper spacing of consecutive markup elements, especially text
  6694 blocks after section headings;
  6695 
  6696 * support bold style (for single symbols only), input syntax is like
  6697 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6698 
  6699 * \<bullet> is now output as bold \cdot by default, which looks much
  6700 better in printed text;
  6701 
  6702 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6703 note that these symbols are currently unavailable in Proof General /
  6704 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6705 
  6706 * isatool latex no longer depends on changed TEXINPUTS, instead
  6707 isatool document copies the Isabelle style files to the target
  6708 location;
  6709 
  6710 
  6711 *** Isar ***
  6712 
  6713 * Pure/Provers: improved proof by cases and induction;
  6714   - 'case' command admits impromptu naming of parameters (such as
  6715     "case (Suc n)");
  6716   - 'induct' method divinates rule instantiation from the inductive
  6717     claim; no longer requires excessive ?P bindings for proper
  6718     instantiation of cases;
  6719   - 'induct' method properly enumerates all possibilities of set/type
  6720     rules; as a consequence facts may be also passed through *type*
  6721     rules without further ado;
  6722   - 'induct' method now derives symbolic cases from the *rulified*
  6723     rule (before it used to rulify cases stemming from the internal
  6724     atomized version); this means that the context of a non-atomic
  6725     statement becomes is included in the hypothesis, avoiding the
  6726     slightly cumbersome show "PROP ?case" form;
  6727   - 'induct' may now use elim-style induction rules without chaining
  6728     facts, using ``missing'' premises from the goal state; this allows
  6729     rules stemming from inductive sets to be applied in unstructured
  6730     scripts, while still benefitting from proper handling of non-atomic
  6731     statements; NB: major inductive premises need to be put first, all
  6732     the rest of the goal is passed through the induction;
  6733   - 'induct' proper support for mutual induction involving non-atomic
  6734     rule statements (uses the new concept of simultaneous goals, see
  6735     below);
  6736   - append all possible rule selections, but only use the first
  6737     success (no backtracking);
  6738   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6739   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6740   - added 'print_induct_rules' (covered by help item in recent Proof
  6741     General versions);
  6742   - moved induct/cases attributes to Pure, methods to Provers;
  6743   - generic method setup instantiated for FOL and HOL;
  6744 
  6745 * Pure: support multiple simultaneous goal statements, for example
  6746 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6747 meta-level mechanism, this acts as if several individual goals had
  6748 been stated separately; in particular common proof methods need to be
  6749 repeated in order to cover all claims; note that a single elimination
  6750 step is *not* sufficient to establish the two conjunctions, so this
  6751 fails:
  6752 
  6753   assume "A & B" then have A and B ..   (*".." fails*)
  6754 
  6755 better use "obtain" in situations as above; alternative refer to
  6756 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6757 
  6758 * Pure: proper integration with ``locales''; unlike the original
  6759 version by Florian Kammller, Isar locales package high-level proof
  6760 contexts rather than raw logical ones (e.g. we admit to include
  6761 attributes everywhere); operations on locales include merge and
  6762 rename; support for implicit arguments (``structures''); simultaneous
  6763 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6764 some examples;
  6765 
  6766 * Pure: the following commands have been ``localized'', supporting a
  6767 target locale specification "(in name)": 'lemma', 'theorem',
  6768 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6769 stored both within the locale and at the theory level (exported and
  6770 qualified by the locale name);
  6771 
  6772 * Pure: theory goals may now be specified in ``long'' form, with
  6773 ad-hoc contexts consisting of arbitrary locale elements. for example
  6774 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6775 definitions may be given, too); the result is a meta-level rule with
  6776 the context elements being discharged in the obvious way;
  6777 
  6778 * Pure: new proof command 'using' allows to augment currently used
  6779 facts after a goal statement ('using' is syntactically analogous to
  6780 'apply', but acts on the goal's facts only); this allows chained facts
  6781 to be separated into parts given before and after a claim, as in
  6782 ``from a and b have C using d and e <proof>'';
  6783 
  6784 * Pure: renamed "antecedent" case to "rule_context";
  6785 
  6786 * Pure: new 'judgment' command records explicit information about the
  6787 object-logic embedding (used by several tools internally); no longer
  6788 use hard-wired "Trueprop";
  6789 
  6790 * Pure: added 'corollary' command;
  6791 
  6792 * Pure: fixed 'token_translation' command;
  6793 
  6794 * Pure: removed obsolete 'exported' attribute;
  6795 
  6796 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6797 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6798 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6799 
  6800 * Pure: method 'atomize' presents local goal premises as object-level
  6801 statements (atomic meta-level propositions); setup controlled via
  6802 rewrite rules declarations of 'atomize' attribute; example
  6803 application: 'induct' method with proper rule statements in improper
  6804 proof *scripts*;
  6805 
  6806 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6807 now consider the syntactic context of assumptions, giving a better
  6808 chance to get type-inference of the arguments right (this is
  6809 especially important for locales);
  6810 
  6811 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6812 mode;
  6813 
  6814 * Pure/obtain: the formal conclusion "thesis", being marked as
  6815 ``internal'', may no longer be reference directly in the text;
  6816 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6817 situations;
  6818 
  6819 * Pure: generic 'sym' attribute which declares a rule both as pure
  6820 'elim?' and for the 'symmetric' operation;
  6821 
  6822 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6823 text; the fixed correlation with particular command syntax has been
  6824 discontinued;
  6825 
  6826 * Pure: new method 'rules' is particularly well-suited for proof
  6827 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6828 but often produces more compact proof terms with less detours;
  6829 
  6830 * Pure/Provers/classical: simplified integration with pure rule
  6831 attributes and methods; the classical "intro?/elim?/dest?"
  6832 declarations coincide with the pure ones; the "rule" method no longer
  6833 includes classically swapped intros; "intro" and "elim" methods no
  6834 longer pick rules from the context; also got rid of ML declarations
  6835 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6836 INCOMPATIBILITY;
  6837 
  6838 * Provers/classical: attribute 'swapped' produces classical inversions
  6839 of introduction rules;
  6840 
  6841 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6842 rules instead of full simplifier context; 'iff' attribute handles
  6843 conditional rules;
  6844 
  6845 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6846 
  6847 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6848 "(permissive)" option to recover old behavior;
  6849 
  6850 * HOL: 'inductive' no longer features separate (collective) attributes
  6851 for 'intros' (was found too confusing);
  6852 
  6853 * HOL: properly declared induction rules less_induct and
  6854 wf_induct_rule;
  6855 
  6856 
  6857 *** HOL ***
  6858 
  6859 * HOL: moved over to sane numeral syntax; the new policy is as
  6860 follows:
  6861 
  6862   - 0 and 1 are polymorphic constants, which are defined on any
  6863   numeric type (nat, int, real etc.);
  6864 
  6865   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6866   binary representation internally;
  6867 
  6868   - type nat has special constructor Suc, and generally prefers Suc 0
  6869   over 1::nat and Suc (Suc 0) over 2::nat;
  6870 
  6871 This change may cause significant problems of INCOMPATIBILITY; here
  6872 are some hints on converting existing sources:
  6873 
  6874   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6875   entities, so expressions involving "-" (unary or binary minus) need
  6876   to be spaced properly;
  6877 
  6878   - existing occurrences of "1" may need to be constraint "1::nat" or
  6879   even replaced by Suc 0; similar for old "2";
  6880 
  6881   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6882 
  6883   - remove all special provisions on numerals in proofs;
  6884 
  6885 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6886 representation (depends on bin_arith_simps in the default context);
  6887 
  6888 * HOL: symbolic syntax for x^2 (numeral 2);
  6889 
  6890 * HOL: the class of all HOL types is now called "type" rather than
  6891 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6892 in axclass/classes, instance/arities, and (usually rare) occurrences
  6893 in typings (of consts etc.); internally the class is called
  6894 "HOL.type", ML programs should refer to HOLogic.typeS;
  6895 
  6896 * HOL/record package improvements:
  6897   - new derived operations "fields" to build a partial record section,
  6898     "extend" to promote a fixed record to a record scheme, and
  6899     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6900     declared as simp by default;
  6901   - shared operations ("more", "fields", etc.) now need to be always
  6902     qualified) --- potential INCOMPATIBILITY;
  6903   - removed "make_scheme" operations (use "make" with "extend") --
  6904     INCOMPATIBILITY;
  6905   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6906   - provides cases/induct rules for use with corresponding Isar
  6907     methods (for concrete records, record schemes, concrete more
  6908     parts, and schematic more parts -- in that order);
  6909   - internal definitions directly based on a light-weight abstract
  6910     theory of product types over typedef rather than datatype;
  6911 
  6912 * HOL: generic code generator for generating executable ML code from
  6913 specifications; specific support for HOL constructs such as inductive
  6914 datatypes and sets, as well as recursive functions; can be invoked
  6915 via 'generate_code' theory section;
  6916 
  6917 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6918 
  6919 * HOL: consolidated and renamed several theories.  In particular:
  6920         Ord.thy has been absorbed into HOL.thy
  6921         String.thy has been absorbed into List.thy
  6922 
  6923 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6924 (beware of argument permutation!);
  6925 
  6926 * HOL: linorder_less_split superseded by linorder_cases;
  6927 
  6928 * HOL/List: "nodups" renamed to "distinct";
  6929 
  6930 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6931 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6932   - Ex_def has changed, now need to use some_eq_ex
  6933 
  6934 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6935 in this (rare) case use:
  6936 
  6937   delSWrapper "split_all_tac"
  6938   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6939 
  6940 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6941 MAY FAIL;
  6942 
  6943 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  6944 Isabelle's type classes, ^ on functions and relations has too general
  6945 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  6946 necessary to attach explicit type constraints;
  6947 
  6948 * HOL/Relation: the prefix name of the infix "O" has been changed from
  6949 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  6950 renamed accordingly (eg "compI" -> "rel_compI").
  6951 
  6952 * HOL: syntax translations now work properly with numerals and records
  6953 expressions;
  6954 
  6955 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  6956 of "lam" -- INCOMPATIBILITY;
  6957 
  6958 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  6959 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  6960 renamed "Product_Type.unit";
  6961 
  6962 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  6963 
  6964 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  6965 the "cases" method);
  6966 
  6967 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  6968 Florian Kammller);
  6969 
  6970 * HOL/IMP: updated and converted to new-style theory format; several
  6971 parts turned into readable document, with proper Isar proof texts and
  6972 some explanations (by Gerwin Klein);
  6973 
  6974 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  6975 
  6976 * HOL-Hyperreal is now a logic image;
  6977 
  6978 
  6979 *** HOLCF ***
  6980 
  6981 * Isar: consts/constdefs supports mixfix syntax for continuous
  6982 operations;
  6983 
  6984 * Isar: domain package adapted to new-style theory format, e.g. see
  6985 HOLCF/ex/Dnat.thy;
  6986 
  6987 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  6988 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  6989 lift.induct_tac, always use UU instead of Undef;
  6990 
  6991 * HOLCF/IMP: updated and converted to new-style theory;
  6992 
  6993 
  6994 *** ZF ***
  6995 
  6996 * Isar: proper integration of logic-specific tools and packages,
  6997 including theory commands '(co)inductive', '(co)datatype',
  6998 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  6999 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  7000 
  7001 * theory Main no longer includes AC; for the Axiom of Choice, base
  7002 your theory on Main_ZFC;
  7003 
  7004 * the integer library now covers quotients and remainders, with many
  7005 laws relating division to addition, multiplication, etc.;
  7006 
  7007 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  7008 typeless version of the formalism;
  7009 
  7010 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  7011 format;
  7012 
  7013 * ZF/Induct: new directory for examples of inductive definitions,
  7014 including theory Multiset for multiset orderings; converted to
  7015 new-style theory format;
  7016 
  7017 * ZF: many new theorems about lists, ordinals, etc.;
  7018 
  7019 
  7020 *** General ***
  7021 
  7022 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  7023 variable proof controls level of detail: 0 = no proofs (only oracle
  7024 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  7025 also ref manual for further ML interfaces;
  7026 
  7027 * Pure/axclass: removed obsolete ML interface
  7028 goal_subclass/goal_arity;
  7029 
  7030 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  7031 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  7032 separate tokens, so expressions involving minus need to be spaced
  7033 properly;
  7034 
  7035 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  7036 rather than "infixl" or "infixr";
  7037 
  7038 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  7039 sort constraint specifications in type inference; e.g. "x::_::foo"
  7040 ensures that the type of "x" is of sort "foo" (but not necessarily a
  7041 type variable);
  7042 
  7043 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  7044 control output of nested => (types); the default behavior is
  7045 "type_brackets";
  7046 
  7047 * Pure/syntax: builtin parse translation for "_constify" turns valued
  7048 tokens into AST constants;
  7049 
  7050 * Pure/syntax: prefer later declarations of translations and print
  7051 translation functions; potential INCOMPATIBILITY: need to reverse
  7052 multiple declarations for same syntax element constant;
  7053 
  7054 * Pure/show_hyps reset by default (in accordance to existing Isar
  7055 practice);
  7056 
  7057 * Provers/classical: renamed addaltern to addafter, addSaltern to
  7058 addSafter;
  7059 
  7060 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  7061 as well;
  7062 
  7063 * system: tested support for MacOS X; should be able to get Isabelle +
  7064 Proof General to work in a plain Terminal after installing Poly/ML
  7065 (e.g. from the Isabelle distribution area) and GNU bash alone
  7066 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  7067 support requires further installations, e.g. from
  7068 http://fink.sourceforge.net/);
  7069 
  7070 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  7071 
  7072 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  7073 of 40 MB), cf. ML_OPTIONS;
  7074 
  7075 * system: Proof General keywords specification is now part of the
  7076 Isabelle distribution (see etc/isar-keywords.el);
  7077 
  7078 * system: support for persistent Proof General sessions (refrain from
  7079 outdating all loaded theories on startup); user may create writable
  7080 logic images like this: ``isabelle -q HOL Test'';
  7081 
  7082 * system: smart selection of Isabelle process versus Isabelle
  7083 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  7084 run both "isabelle" and "Isabelle" even if file names are badly
  7085 damaged (executable inspects the case of the first letter of its own
  7086 name); added separate "isabelle-process" and "isabelle-interface";
  7087 
  7088 * system: refrain from any attempt at filtering input streams; no
  7089 longer support ``8bit'' encoding of old isabelle font, instead proper
  7090 iso-latin characters may now be used; the related isatools
  7091 "symbolinput" and "nonascii" have disappeared as well;
  7092 
  7093 * system: removed old "xterm" interface (the print modes "xterm" and
  7094 "xterm_color" are still available for direct use in a suitable
  7095 terminal);
  7096 
  7097 
  7098 
  7099 New in Isabelle99-2 (February 2001)
  7100 -----------------------------------
  7101 
  7102 *** Overview of INCOMPATIBILITIES ***
  7103 
  7104 * HOL: please note that theories in the Library and elsewhere often use the
  7105 new-style (Isar) format; to refer to their theorems in an ML script you must
  7106 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  7107 
  7108 * HOL: inductive package no longer splits induction rule aggressively,
  7109 but only as far as specified by the introductions given; the old
  7110 format may be recovered via ML function complete_split_rule or attribute
  7111 'split_rule (complete)';
  7112 
  7113 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  7114 gfp_Tarski to gfp_unfold;
  7115 
  7116 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  7117 
  7118 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  7119 relation); infix "^^" has been renamed "``"; infix "``" has been
  7120 renamed "`"; "univalent" has been renamed "single_valued";
  7121 
  7122 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  7123 operation;
  7124 
  7125 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  7126 
  7127 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  7128 
  7129 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  7130 consequence, it is no longer monotonic wrt. the local goal context
  7131 (which is now passed through the inductive cases);
  7132 
  7133 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  7134 \<gg> to \<ggreater>;
  7135 
  7136 
  7137 *** Document preparation ***
  7138 
  7139 * \isabellestyle{NAME} selects version of Isabelle output (currently
  7140 available: are "it" for near math-mode best-style output, "sl" for
  7141 slanted text style, and "tt" for plain type-writer; if no
  7142 \isabellestyle command is given, output is according to slanted
  7143 type-writer);
  7144 
  7145 * support sub/super scripts (for single symbols only), input syntax is
  7146 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  7147 
  7148 * some more standard symbols; see Appendix A of the system manual for
  7149 the complete list of symbols defined in isabellesym.sty;
  7150 
  7151 * improved isabelle style files; more abstract symbol implementation
  7152 (should now use \isamath{...} and \isatext{...} in custom symbol
  7153 definitions);
  7154 
  7155 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  7156 state; Note that presentation of goal states does not conform to
  7157 actual human-readable proof documents.  Please do not include goal
  7158 states into document output unless you really know what you are doing!
  7159 
  7160 * proper indentation of antiquoted output with proportional LaTeX
  7161 fonts;
  7162 
  7163 * no_document ML operator temporarily disables LaTeX document
  7164 generation;
  7165 
  7166 * isatool unsymbolize tunes sources for plain ASCII communication;
  7167 
  7168 
  7169 *** Isar ***
  7170 
  7171 * Pure: Isar now suffers initial goal statements to contain unbound
  7172 schematic variables (this does not conform to actual readable proof
  7173 documents, due to unpredictable outcome and non-compositional proof
  7174 checking); users who know what they are doing may use schematic goals
  7175 for Prolog-style synthesis of proven results;
  7176 
  7177 * Pure: assumption method (an implicit finishing) now handles actual
  7178 rules as well;
  7179 
  7180 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  7181 initial goal, declare "that" only as Pure intro (only for single
  7182 steps); the "that" rule assumption may now be involved in implicit
  7183 finishing, thus ".." becomes a feasible for trivial obtains;
  7184 
  7185 * Pure: default proof step now includes 'intro_classes'; thus trivial
  7186 instance proofs may be performed by "..";
  7187 
  7188 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  7189 statements as well;
  7190 
  7191 * Pure: more robust selection of calculational rules;
  7192 
  7193 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  7194 rule (as well as the assumption rule);
  7195 
  7196 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  7197 lemmas, using the graph browser tool;
  7198 
  7199 * Pure: predict failure of "show" in interactive mode;
  7200 
  7201 * Pure: 'thms_containing' now takes actual terms as arguments;
  7202 
  7203 * HOL: improved method 'induct' --- now handles non-atomic goals
  7204 (potential INCOMPATIBILITY); tuned error handling;
  7205 
  7206 * HOL: cases and induct rules now provide explicit hints about the
  7207 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  7208 any remaining facts are inserted into the goal verbatim;
  7209 
  7210 * HOL: local contexts (aka cases) may now contain term bindings as
  7211 well; the 'cases' and 'induct' methods new provide a ?case binding for
  7212 the result to be shown in each case;
  7213 
  7214 * HOL: added 'recdef_tc' command;
  7215 
  7216 * isatool convert assists in eliminating legacy ML scripts;
  7217 
  7218 
  7219 *** HOL ***
  7220 
  7221 * HOL/Library: a collection of generic theories to be used together
  7222 with main HOL; the theory loader path already includes this directory
  7223 by default; the following existing theories have been moved here:
  7224 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  7225 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  7226 
  7227 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  7228 modelling and verification task performed in Isabelle/HOL +
  7229 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  7230 
  7231 * HOL/Algebra: special summation operator SUM no longer exists, it has
  7232 been replaced by setsum; infix 'assoc' now has priority 50 (like
  7233 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  7234 'domain', this makes the theory consistent with mathematical
  7235 literature;
  7236 
  7237 * HOL basics: added overloaded operations "inverse" and "divide"
  7238 (infix "/"), syntax for generic "abs" operation, generic summation
  7239 operator \<Sum>;
  7240 
  7241 * HOL/typedef: simplified package, provide more useful rules (see also
  7242 HOL/subset.thy);
  7243 
  7244 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  7245 now expressed as a proper nested rule (old-style tactic scripts may
  7246 require atomize_strip_tac to cope with non-atomic premises);
  7247 
  7248 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  7249 to "split_conv" (old name still available for compatibility);
  7250 
  7251 * HOL: improved concrete syntax for strings (e.g. allows translation
  7252 rules with string literals);
  7253 
  7254 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  7255  and Fleuriot's mechanization of analysis, including the transcendental
  7256  functions for the reals;
  7257 
  7258 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  7259 
  7260 
  7261 *** CTT ***
  7262 
  7263 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  7264 "lam" is displayed as TWO lambda-symbols
  7265 
  7266 * CTT: theory Main now available, containing everything (that is, Bool
  7267 and Arith);
  7268 
  7269 
  7270 *** General ***
  7271 
  7272 * Pure: the Simplifier has been implemented properly as a derived rule
  7273 outside of the actual kernel (at last!); the overall performance
  7274 penalty in practical applications is about 50%, while reliability of
  7275 the Isabelle inference kernel has been greatly improved;
  7276 
  7277 * print modes "brackets" and "no_brackets" control output of nested =>
  7278 (types) and ==> (props); the default behaviour is "brackets";
  7279 
  7280 * Provers: fast_tac (and friends) now handle actual object-logic rules
  7281 as assumptions as well;
  7282 
  7283 * system: support Poly/ML 4.0;
  7284 
  7285 * system: isatool install handles KDE version 1 or 2;
  7286 
  7287 
  7288 
  7289 New in Isabelle99-1 (October 2000)
  7290 ----------------------------------
  7291 
  7292 *** Overview of INCOMPATIBILITIES ***
  7293 
  7294 * HOL: simplification of natural numbers is much changed; to partly
  7295 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  7296 issue the following ML commands:
  7297 
  7298   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  7299   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  7300 
  7301 * HOL: simplification no longer dives into case-expressions; this is
  7302 controlled by "t.weak_case_cong" for each datatype t;
  7303 
  7304 * HOL: nat_less_induct renamed to less_induct;
  7305 
  7306 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  7307 fixsome to patch .thy and .ML sources automatically;
  7308 
  7309   select_equality  -> some_equality
  7310   select_eq_Ex     -> some_eq_ex
  7311   selectI2EX       -> someI2_ex
  7312   selectI2         -> someI2
  7313   selectI          -> someI
  7314   select1_equality -> some1_equality
  7315   Eps_sym_eq       -> some_sym_eq_trivial
  7316   Eps_eq           -> some_eq_trivial
  7317 
  7318 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  7319 
  7320 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  7321 instead);
  7322 
  7323 * HOL: the recursion equations generated by 'recdef' are now called
  7324 f.simps instead of f.rules;
  7325 
  7326 * HOL: qed_spec_mp now also handles bounded ALL as well;
  7327 
  7328 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  7329 sometimes be needed;
  7330 
  7331 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  7332 
  7333 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  7334 
  7335 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  7336 product is now "<*>" instead of "Times"; the lexicographic product is
  7337 now "<*lex*>" instead of "**";
  7338 
  7339 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  7340 of main HOL, but was unused); better use HOL's datatype package;
  7341 
  7342 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  7343 the old syntax may be recovered as follows:
  7344 
  7345   syntax (symbols)
  7346     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  7347       (infixl "\\<oplus>" 100)
  7348 
  7349 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  7350 
  7351 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  7352 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  7353 internally;
  7354 
  7355 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  7356 changed from A/r to A//r;
  7357 
  7358 * ZF: new treatment of arithmetic (nat & int) may break some old
  7359 proofs;
  7360 
  7361 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  7362 rulify -> rule_format, elimify -> elim_format, ...);
  7363 
  7364 * Isar/Provers: intro/elim/dest attributes changed; renamed
  7365 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  7366 should have to change intro!! to intro? only); replaced "delrule" by
  7367 "rule del";
  7368 
  7369 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  7370 
  7371 * Provers: strengthened force_tac by using new first_best_tac;
  7372 
  7373 * LaTeX document preparation: several changes of isabelle.sty (see
  7374 lib/texinputs);
  7375 
  7376 
  7377 *** Document preparation ***
  7378 
  7379 * formal comments (text blocks etc.) in new-style theories may now
  7380 contain antiquotations of thm/prop/term/typ/text to be presented
  7381 according to latex print mode; concrete syntax is like this:
  7382 @{term[show_types] "f(x) = a + x"};
  7383 
  7384 * isatool mkdir provides easy setup of Isabelle session directories,
  7385 including proper document sources;
  7386 
  7387 * generated LaTeX sources are now deleted after successful run
  7388 (isatool document -c); may retain a copy somewhere else via -D option
  7389 of isatool usedir;
  7390 
  7391 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  7392 style files, achieving self-contained LaTeX sources and simplifying
  7393 LaTeX debugging;
  7394 
  7395 * old-style theories now produce (crude) LaTeX output as well;
  7396 
  7397 * browser info session directories are now self-contained (may be put
  7398 on WWW server seperately); improved graphs of nested sessions; removed
  7399 graph for 'all sessions';
  7400 
  7401 * several improvements in isabelle style files; \isabellestyle{it}
  7402 produces fake math mode output; \isamarkupheader is now \section by
  7403 default; see lib/texinputs/isabelle.sty etc.;
  7404 
  7405 
  7406 *** Isar ***
  7407 
  7408 * Isar/Pure: local results and corresponding term bindings are now
  7409 subject to Hindley-Milner polymorphism (similar to ML); this
  7410 accommodates incremental type-inference very nicely;
  7411 
  7412 * Isar/Pure: new derived language element 'obtain' supports
  7413 generalized existence reasoning;
  7414 
  7415 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  7416 support accumulation of results, without applying any rules yet;
  7417 useful to collect intermediate results without explicit name
  7418 references, and for use with transitivity rules with more than 2
  7419 premises;
  7420 
  7421 * Isar/Pure: scalable support for case-analysis type proofs: new
  7422 'case' language element refers to local contexts symbolically, as
  7423 produced by certain proof methods; internally, case names are attached
  7424 to theorems as "tags";
  7425 
  7426 * Isar/Pure: theory command 'hide' removes declarations from
  7427 class/type/const name spaces;
  7428 
  7429 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  7430 indicate potential overloading;
  7431 
  7432 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  7433 
  7434 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  7435 "{a,b,c}" instead of {a,b,c};
  7436 
  7437 * Isar/Pure now provides its own version of intro/elim/dest
  7438 attributes; useful for building new logics, but beware of confusion
  7439 with the version in Provers/classical;
  7440 
  7441 * Isar/Pure: the local context of (non-atomic) goals is provided via
  7442 case name 'antecedent';
  7443 
  7444 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  7445 to the current context is now done automatically);
  7446 
  7447 * Isar/Pure: theory command 'method_setup' provides a simple interface
  7448 for definining proof methods in ML;
  7449 
  7450 * Isar/Provers: intro/elim/dest attributes changed; renamed
  7451 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  7452 most cases, one should have to change intro!! to intro? only);
  7453 replaced "delrule" by "rule del";
  7454 
  7455 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  7456 'symmetric' attribute (the latter supercedes [RS sym]);
  7457 
  7458 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  7459 method modifier); 'simp' method: 'only:' modifier removes loopers as
  7460 well (including splits);
  7461 
  7462 * Isar/Provers: Simplifier and Classical methods now support all kind
  7463 of modifiers used in the past, including 'cong', 'iff', etc.
  7464 
  7465 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  7466 of Simplifier and Classical reasoner);
  7467 
  7468 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  7469 now support named cases; major packages (inductive, datatype, primrec,
  7470 recdef) support case names and properly name parameters;
  7471 
  7472 * Isar/HOL: new transitivity rules for substitution in inequalities --
  7473 monotonicity conditions are extracted to be proven at end of
  7474 calculations;
  7475 
  7476 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  7477 method anyway;
  7478 
  7479 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  7480 split_if split_if_asm; datatype package provides theorems foo.splits =
  7481 foo.split foo.split_asm for each datatype;
  7482 
  7483 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  7484 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  7485 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  7486 use "(cases (simplified))" method in proper proof texts);
  7487 
  7488 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  7489 
  7490 * Isar: names of theorems etc. may be natural numbers as well;
  7491 
  7492 * Isar: 'pr' command: optional arguments for goals_limit and
  7493 ProofContext.prems_limit; no longer prints theory contexts, but only
  7494 proof states;
  7495 
  7496 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  7497 additional print modes to be specified; e.g. "pr(latex)" will print
  7498 proof state according to the Isabelle LaTeX style;
  7499 
  7500 * Isar: improved support for emulating tactic scripts, including proof
  7501 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  7502 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  7503 (for HOL datatypes);
  7504 
  7505 * Isar: simplified (more robust) goal selection of proof methods: 1st
  7506 goal, all goals, or explicit goal specifier (tactic emulation); thus
  7507 'proof method scripts' have to be in depth-first order;
  7508 
  7509 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  7510 
  7511 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  7512 should instead use individual commands for printing items
  7513 (print_commands, print_methods etc.);
  7514 
  7515 * Isar: added 'nothing' --- the empty list of theorems;
  7516 
  7517 
  7518 *** HOL ***
  7519 
  7520 * HOL/MicroJava: formalization of a fragment of Java, together with a
  7521 corresponding virtual machine and a specification of its bytecode
  7522 verifier and a lightweight bytecode verifier, including proofs of
  7523 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  7524 Cornelia Pusch (see also the homepage of project Bali at
  7525 http://isabelle.in.tum.de/Bali/);
  7526 
  7527 * HOL/Algebra: new theory of rings and univariate polynomials, by
  7528 Clemens Ballarin;
  7529 
  7530 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  7531 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  7532 Rasmussen;
  7533 
  7534 * HOL/Lattice: fundamental concepts of lattice theory and order
  7535 structures, including duals, properties of bounds versus algebraic
  7536 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  7537 Theorem for complete lattices etc.; may also serve as a demonstration
  7538 for abstract algebraic reasoning using axiomatic type classes, and
  7539 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  7540 
  7541 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  7542 von Oheimb;
  7543 
  7544 * HOL/IMPP: extension of IMP with local variables and mutually
  7545 recursive procedures, by David von Oheimb;
  7546 
  7547 * HOL/Lambda: converted into new-style theory and document;
  7548 
  7549 * HOL/ex/Multiquote: example of multiple nested quotations and
  7550 anti-quotations -- basically a generalized version of de-Bruijn
  7551 representation; very useful in avoiding lifting of operations;
  7552 
  7553 * HOL/record: added general record equality rule to simpset; fixed
  7554 select-update simplification procedure to handle extended records as
  7555 well; admit "r" as field name;
  7556 
  7557 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  7558 other numeric types and also as the identity of groups, rings, etc.;
  7559 
  7560 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  7561 Types nat and int belong to this axclass;
  7562 
  7563 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  7564    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  7565    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  7566   two terms #m*u and #n*u are replaced by #(m+n)*u
  7567     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  7568   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  7569     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  7570 
  7571 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  7572 powerful prover for predicate logic but knows nothing of clasets; see
  7573 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  7574 
  7575 * HOL: new version of "case_tac" subsumes both boolean case split and
  7576 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  7577 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  7578 
  7579 * HOL: simplification no longer dives into case-expressions: only the
  7580 selector expression is simplified, but not the remaining arms; to
  7581 enable full simplification of case-expressions for datatype t, you may
  7582 remove t.weak_case_cong from the simpset, either globally (Delcongs
  7583 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  7584 
  7585 * HOL/recdef: the recursion equations generated by 'recdef' for
  7586 function 'f' are now called f.simps instead of f.rules; if all
  7587 termination conditions are proved automatically, these simplification
  7588 rules are added to the simpset, as in primrec; rules may be named
  7589 individually as well, resulting in a separate list of theorems for
  7590 each equation;
  7591 
  7592 * HOL/While is a new theory that provides a while-combinator. It
  7593 permits the definition of tail-recursive functions without the
  7594 provision of a termination measure. The latter is necessary once the
  7595 invariant proof rule for while is applied.
  7596 
  7597 * HOL: new (overloaded) notation for the set of elements below/above
  7598 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  7599 
  7600 * HOL: theorems impI, allI, ballI bound as "strip";
  7601 
  7602 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  7603 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  7604 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  7605 
  7606 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  7607 
  7608 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  7609 main HOL, but was unused);
  7610 
  7611 * HOL: fewer consts declared as global (e.g. have to refer to
  7612 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  7613 
  7614 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  7615 in case of overlap with user translations (e.g. judgements over
  7616 tuples); (note that the underlying logical represenation is still
  7617 bogus);
  7618 
  7619 
  7620 *** ZF ***
  7621 
  7622 * ZF: simplification automatically cancels common terms in arithmetic
  7623 expressions over nat and int;
  7624 
  7625 * ZF: new treatment of nat to minimize type-checking: all operators
  7626 coerce their operands to a natural number using the function natify,
  7627 making the algebraic laws unconditional;
  7628 
  7629 * ZF: as above, for int: operators coerce their operands to an integer
  7630 using the function intify;
  7631 
  7632 * ZF: the integer library now contains many of the usual laws for the
  7633 orderings, including $<=, and monotonicity laws for $+ and $*;
  7634 
  7635 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  7636 simplification;
  7637 
  7638 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  7639 to the simplifier and classical reasoner simultaneously;
  7640 
  7641 
  7642 *** General ***
  7643 
  7644 * Provers: blast_tac now handles actual object-logic rules as
  7645 assumptions; note that auto_tac uses blast_tac internally as well;
  7646 
  7647 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  7648 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  7649 
  7650 * Provers: delrules now handles destruct rules as well (no longer need
  7651 explicit make_elim);
  7652 
  7653 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  7654   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7655 use instead the strong form,
  7656   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7657 in HOL, FOL and ZF the function cla_make_elim will create such rules
  7658 from destruct-rules;
  7659 
  7660 * Provers: Simplifier.easy_setup provides a fast path to basic
  7661 Simplifier setup for new object-logics;
  7662 
  7663 * Pure: AST translation rules no longer require constant head on LHS;
  7664 
  7665 * Pure: improved name spaces: ambiguous output is qualified; support
  7666 for hiding of names;
  7667 
  7668 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  7669 XSYMBOL_HOME; no longer need to do manual configuration in most
  7670 situations;
  7671 
  7672 * system: compression of ML heaps images may now be controlled via -c
  7673 option of isabelle and isatool usedir (currently only observed by
  7674 Poly/ML);
  7675 
  7676 * system: isatool installfonts may handle X-Symbol fonts as well (very
  7677 useful for remote X11);
  7678 
  7679 * system: provide TAGS file for Isabelle sources;
  7680 
  7681 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  7682 order;
  7683 
  7684 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  7685 timing flag supersedes proof_timing and Toplevel.trace;
  7686 
  7687 * ML: new combinators |>> and |>>> for incremental transformations
  7688 with secondary results (e.g. certain theory extensions):
  7689 
  7690 * ML: PureThy.add_defs gets additional argument to indicate potential
  7691 overloading (usually false);
  7692 
  7693 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  7694 results;
  7695 
  7696 
  7697 
  7698 New in Isabelle99 (October 1999)
  7699 --------------------------------
  7700 
  7701 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7702 
  7703 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  7704 are no longer simplified.  (This allows the simplifier to unfold recursive
  7705 functional programs.)  To restore the old behaviour, declare
  7706 
  7707     Delcongs [if_weak_cong];
  7708 
  7709 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  7710 complement;
  7711 
  7712 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  7713 
  7714 * HOL/datatype: mutual_induct_tac no longer exists --
  7715   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  7716 
  7717 * HOL/typedef: fixed type inference for representing set; type
  7718 arguments now have to occur explicitly on the rhs as type constraints;
  7719 
  7720 * ZF: The con_defs part of an inductive definition may no longer refer
  7721 to constants declared in the same theory;
  7722 
  7723 * HOL, ZF: the function mk_cases, generated by the inductive
  7724 definition package, has lost an argument.  To simplify its result, it
  7725 uses the default simpset instead of a supplied list of theorems.
  7726 
  7727 * HOL/List: the constructors of type list are now Nil and Cons;
  7728 
  7729 * Simplifier: the type of the infix ML functions
  7730         setSSolver addSSolver setSolver addSolver
  7731 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  7732 for packaging solvers. A solver is created via
  7733         mk_solver: string -> (thm list -> int -> tactic) -> solver
  7734 where the string argument is only a comment.
  7735 
  7736 
  7737 *** Proof tools ***
  7738 
  7739 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  7740 decision procedure for linear arithmetic. Currently it is used for
  7741 types `nat', `int', and `real' in HOL (see below); it can, should and
  7742 will be instantiated for other types and logics as well.
  7743 
  7744 * The simplifier now accepts rewrite rules with flexible heads, eg
  7745      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  7746   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  7747   matching.
  7748 
  7749 
  7750 *** General ***
  7751 
  7752 * New Isabelle/Isar subsystem provides an alternative to traditional
  7753 tactical theorem proving; together with the ProofGeneral/isar user
  7754 interface it offers an interactive environment for developing human
  7755 readable proof documents (Isar == Intelligible semi-automated
  7756 reasoning); for further information see isatool doc isar-ref,
  7757 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  7758 
  7759 * improved and simplified presentation of theories: better HTML markup
  7760 (including colors), graph views in several sizes; isatool usedir now
  7761 provides a proper interface for user theories (via -P option); actual
  7762 document preparation based on (PDF)LaTeX is available as well (for
  7763 new-style theories only); see isatool doc system for more information;
  7764 
  7765 * native support for Proof General, both for classic Isabelle and
  7766 Isabelle/Isar;
  7767 
  7768 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  7769 using the graph browser tool;
  7770 
  7771 * Isabelle manuals now also available as PDF;
  7772 
  7773 * theory loader rewritten from scratch (may not be fully
  7774 bug-compatible); old loadpath variable has been replaced by show_path,
  7775 add_path, del_path, reset_path functions; new operations such as
  7776 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  7777 isatool doc ref);
  7778 
  7779 * improved isatool install: option -k creates KDE application icon,
  7780 option -p DIR installs standalone binaries;
  7781 
  7782 * added ML_PLATFORM setting (useful for cross-platform installations);
  7783 more robust handling of platform specific ML images for SML/NJ;
  7784 
  7785 * the settings environment is now statically scoped, i.e. it is never
  7786 created again in sub-processes invoked from isabelle, isatool, or
  7787 Isabelle;
  7788 
  7789 * path element specification '~~' refers to '$ISABELLE_HOME';
  7790 
  7791 * in locales, the "assumes" and "defines" parts may be omitted if
  7792 empty;
  7793 
  7794 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  7795 long arrows);
  7796 
  7797 * new print_mode "HTML";
  7798 
  7799 * new flag show_tags controls display of tags of theorems (which are
  7800 basically just comments that may be attached by some tools);
  7801 
  7802 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  7803 mode and goal output format:
  7804 
  7805 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  7806 244c244
  7807 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  7808 ---
  7809 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  7810 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  7811 181c181
  7812 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  7813 ---
  7814 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  7815 
  7816 * function bind_thms stores lists of theorems (cf. bind_thm);
  7817 
  7818 * new shorthand tactics ftac, eatac, datac, fatac;
  7819 
  7820 * qed (and friends) now accept "" as result name; in that case the
  7821 theorem is not stored, but proper checks and presentation of the
  7822 result still apply;
  7823 
  7824 * theorem database now also indexes constants "Trueprop", "all",
  7825 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  7826 
  7827 
  7828 *** HOL ***
  7829 
  7830 ** HOL arithmetic **
  7831 
  7832 * There are now decision procedures for linear arithmetic over nat and
  7833 int:
  7834 
  7835 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  7836 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  7837 are treated as atomic; subformulae not involving type `nat' or `int'
  7838 are ignored; quantified subformulae are ignored unless they are
  7839 positive universal or negative existential. The tactic has to be
  7840 invoked by hand and can be a little bit slow. In particular, the
  7841 running time is exponential in the number of occurrences of `min' and
  7842 `max', and `-' on `nat'.
  7843 
  7844 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  7845 (negated) (in)equalities among the premises and the conclusion into
  7846 account (i.e. no compound formulae) and does not know about `min' and
  7847 `max', and `-' on `nat'. It is fast and is used automatically by the
  7848 simplifier.
  7849 
  7850 NB: At the moment, these decision procedures do not cope with mixed
  7851 nat/int formulae where the two parts interact, such as `m < n ==>
  7852 int(m) < int(n)'.
  7853 
  7854 * HOL/Numeral provides a generic theory of numerals (encoded
  7855 efficiently as bit strings); setup for types nat/int/real is in place;
  7856 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  7857 int, existing theories and proof scripts may require a few additional
  7858 type constraints;
  7859 
  7860 * integer division and remainder can now be performed on constant
  7861 arguments;
  7862 
  7863 * many properties of integer multiplication, division and remainder
  7864 are now available;
  7865 
  7866 * An interface to the Stanford Validity Checker (SVC) is available through the
  7867 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  7868 are proved automatically.  SVC must be installed separately, and its results
  7869 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  7870 invocation of the underlying oracle).  For SVC see
  7871   http://verify.stanford.edu/SVC
  7872 
  7873 * IsaMakefile: the HOL-Real target now builds an actual image;
  7874 
  7875 
  7876 ** HOL misc **
  7877 
  7878 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  7879 (in Isabelle/Isar) -- by Gertrud Bauer;
  7880 
  7881 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  7882 analysis for assembly languages with subtypes;
  7883 
  7884 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  7885 -- avoids syntactic ambiguities and treats state, transition, and
  7886 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  7887 changed syntax and (many) tactics;
  7888 
  7889 * HOL/inductive: Now also handles more general introduction rules such
  7890   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  7891   theorems are now maintained within the theory (maintained via the
  7892   "mono" attribute);
  7893 
  7894 * HOL/datatype: Now also handles arbitrarily branching datatypes
  7895   (using function types) such as
  7896 
  7897   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  7898 
  7899 * HOL/record: record_simproc (part of the default simpset) takes care
  7900 of selectors applied to updated records; record_split_tac is no longer
  7901 part of the default claset; update_defs may now be removed from the
  7902 simpset in many cases; COMPATIBILITY: old behavior achieved by
  7903 
  7904   claset_ref () := claset() addSWrapper record_split_wrapper;
  7905   Delsimprocs [record_simproc]
  7906 
  7907 * HOL/typedef: fixed type inference for representing set; type
  7908 arguments now have to occur explicitly on the rhs as type constraints;
  7909 
  7910 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  7911 names rather than an ML expression;
  7912 
  7913 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  7914 supplied later.  Program schemes can be defined, such as
  7915     "While B C s = (if B s then While B C (C s) else s)"
  7916 where the well-founded relation can be chosen after B and C have been given.
  7917 
  7918 * HOL/List: the constructors of type list are now Nil and Cons;
  7919 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  7920 course, ML tools referring to List.list.op # etc. have to be adapted;
  7921 
  7922 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  7923 disabled by default; run isabelle with option -m HOL to get back to
  7924 the original Gordon/HOL-style output;
  7925 
  7926 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  7927 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  7928 
  7929 * HOL basic syntax simplified (more orthogonal): all variants of
  7930 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  7931 Eps operator is provided as well: "SOME x. P[x]";
  7932 
  7933 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  7934 
  7935 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  7936 thus available for user theories;
  7937 
  7938 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  7939 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  7940 time;
  7941 
  7942 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  7943 several times and then mp;
  7944 
  7945 
  7946 *** LK ***
  7947 
  7948 * the notation <<...>> is now available as a notation for sequences of
  7949 formulas;
  7950 
  7951 * the simplifier is now installed
  7952 
  7953 * the axiom system has been generalized (thanks to Soren Heilmann)
  7954 
  7955 * the classical reasoner now has a default rule database
  7956 
  7957 
  7958 *** ZF ***
  7959 
  7960 * new primrec section allows primitive recursive functions to be given
  7961 directly (as in HOL) over datatypes and the natural numbers;
  7962 
  7963 * new tactics induct_tac and exhaust_tac for induction (or case
  7964 analysis) over datatypes and the natural numbers;
  7965 
  7966 * the datatype declaration of type T now defines the recursor T_rec;
  7967 
  7968 * simplification automatically does freeness reasoning for datatype
  7969 constructors;
  7970 
  7971 * automatic type-inference, with AddTCs command to insert new
  7972 type-checking rules;
  7973 
  7974 * datatype introduction rules are now added as Safe Introduction rules
  7975 to the claset;
  7976 
  7977 * the syntax "if P then x else y" is now available in addition to
  7978 if(P,x,y);
  7979 
  7980 
  7981 *** Internal programming interfaces ***
  7982 
  7983 * tuned simplifier trace output; new flag debug_simp;
  7984 
  7985 * structures Vartab / Termtab (instances of TableFun) offer efficient
  7986 tables indexed by indexname_ord / term_ord (compatible with aconv);
  7987 
  7988 * AxClass.axclass_tac lost the theory argument;
  7989 
  7990 * tuned current_goals_markers semantics: begin / end goal avoids
  7991 printing empty lines;
  7992 
  7993 * removed prs and prs_fn hook, which was broken because it did not
  7994 include \n in its semantics, forcing writeln to add one
  7995 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  7996 string -> unit if you really want to output text without newline;
  7997 
  7998 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  7999 plain output, interface builders may have to enable 'isabelle_font'
  8000 mode to get Isabelle font glyphs as before;
  8001 
  8002 * refined token_translation interface; INCOMPATIBILITY: output length
  8003 now of type real instead of int;
  8004 
  8005 * theory loader actions may be traced via new ThyInfo.add_hook
  8006 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  8007 your own database of information attached to *whole* theories -- as
  8008 opposed to intra-theory data slots offered via TheoryDataFun;
  8009 
  8010 * proper handling of dangling sort hypotheses (at last!);
  8011 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  8012 extra sort hypotheses that can be witnessed from the type signature;
  8013 the force_strip_shyps flag is gone, any remaining shyps are simply
  8014 left in the theorem (with a warning issued by strip_shyps_warning);
  8015 
  8016 
  8017 
  8018 New in Isabelle98-1 (October 1998)
  8019 ----------------------------------
  8020 
  8021 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  8022 
  8023 * several changes of automated proof tools;
  8024 
  8025 * HOL: major changes to the inductive and datatype packages, including
  8026 some minor incompatibilities of theory syntax;
  8027 
  8028 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  8029 called `inj_on';
  8030 
  8031 * HOL: removed duplicate thms in Arith:
  8032   less_imp_add_less  should be replaced by  trans_less_add1
  8033   le_imp_add_le      should be replaced by  trans_le_add1
  8034 
  8035 * HOL: unary minus is now overloaded (new type constraints may be
  8036 required);
  8037 
  8038 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  8039 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  8040 now taken as an integer constant.
  8041 
  8042 * Pure: ML function 'theory_of' renamed to 'theory';
  8043 
  8044 
  8045 *** Proof tools ***
  8046 
  8047 * Simplifier:
  8048   1. Asm_full_simp_tac is now more aggressive.
  8049      1. It will sometimes reorient premises if that increases their power to
  8050         simplify.
  8051      2. It does no longer proceed strictly from left to right but may also
  8052         rotate premises to achieve further simplification.
  8053      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  8054      old Asm_full_simp_tac in that it does not rotate premises.
  8055   2. The simplifier now knows a little bit about nat-arithmetic.
  8056 
  8057 * Classical reasoner: wrapper mechanism for the classical reasoner now
  8058 allows for selected deletion of wrappers, by introduction of names for
  8059 wrapper functionals.  This implies that addbefore, addSbefore,
  8060 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  8061 and that adding two tactics with the same name overwrites the first
  8062 one (emitting a warning).
  8063   type wrapper = (int -> tactic) -> (int -> tactic)
  8064   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  8065   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  8066   delWrapper, delSWrapper: claset *  string            -> claset
  8067   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  8068 
  8069 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  8070 semantics; addbefore now affects only the unsafe part of step_tac
  8071 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  8072 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  8073 by Force_tac;
  8074 
  8075 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  8076 compWrapper; added safe wrapper (and access functions for it);
  8077 
  8078 * HOL/split_all_tac is now much faster and fails if there is nothing
  8079 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  8080 and the names of the automatically generated variables have changed.
  8081 split_all_tac has moved within claset() from unsafe wrappers to safe
  8082 wrappers, which means that !!-bound variables are split much more
  8083 aggressively, and safe_tac and clarify_tac now split such variables.
  8084 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  8085 Note: the same holds for record_split_tac, which does the job of
  8086 split_all_tac for record fields.
  8087 
  8088 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  8089 permanently to the default simpset using Addsplits just like
  8090 Addsimps. They can be removed via Delsplits just like
  8091 Delsimps. Lower-case versions are also available.
  8092 
  8093 * HOL/Simplifier: The rule split_if is now part of the default
  8094 simpset. This means that the simplifier will eliminate all occurrences
  8095 of if-then-else in the conclusion of a goal. To prevent this, you can
  8096 either remove split_if completely from the default simpset by
  8097 `Delsplits [split_if]' or remove it in a specific call of the
  8098 simplifier using `... delsplits [split_if]'.  You can also add/delete
  8099 other case splitting rules to/from the default simpset: every datatype
  8100 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  8101 t is the name of the datatype).
  8102 
  8103 * Classical reasoner / Simplifier combination: new force_tac (and
  8104 derivatives Force_tac, force) combines rewriting and classical
  8105 reasoning (and whatever other tools) similarly to auto_tac, but is
  8106 aimed to solve the given subgoal completely.
  8107 
  8108 
  8109 *** General ***
  8110 
  8111 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  8112 and `goalw': the theory is no longer needed as an explicit argument -
  8113 the current theory context is used; assumptions are no longer returned
  8114 at the ML-level unless one of them starts with ==> or !!; it is
  8115 recommended to convert to these new commands using isatool fixgoal
  8116 (backup your sources first!);
  8117 
  8118 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  8119 the current theory context, and 'theory' to lookup stored theories;
  8120 
  8121 * new theory section 'locale' for declaring constants, assumptions and
  8122 definitions that have local scope;
  8123 
  8124 * new theory section 'nonterminals' for purely syntactic types;
  8125 
  8126 * new theory section 'setup' for generic ML setup functions
  8127 (e.g. package initialization);
  8128 
  8129 * the distribution now includes Isabelle icons: see
  8130 lib/logo/isabelle-{small,tiny}.xpm;
  8131 
  8132 * isatool install - install binaries with absolute references to
  8133 ISABELLE_HOME/bin;
  8134 
  8135 * isatool logo -- create instances of the Isabelle logo (as EPS);
  8136 
  8137 * print mode 'emacs' reserved for Isamode;
  8138 
  8139 * support multiple print (ast) translations per constant name;
  8140 
  8141 * theorems involving oracles are now printed with a suffixed [!];
  8142 
  8143 
  8144 *** HOL ***
  8145 
  8146 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  8147 
  8148 * HOL/inductive package reorganized and improved: now supports mutual
  8149 definitions such as
  8150 
  8151   inductive EVEN ODD
  8152     intrs
  8153       null "0 : EVEN"
  8154       oddI "n : EVEN ==> Suc n : ODD"
  8155       evenI "n : ODD ==> Suc n : EVEN"
  8156 
  8157 new theorem list "elims" contains an elimination rule for each of the
  8158 recursive sets; inductive definitions now handle disjunctive premises
  8159 correctly (also ZF);
  8160 
  8161 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  8162 "mutual_induct" no longer exists - the induction rule is always
  8163 contained in "induct";
  8164 
  8165 
  8166 * HOL/datatype package re-implemented and greatly improved: now
  8167 supports mutually recursive datatypes such as
  8168 
  8169   datatype
  8170     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  8171             | SUM ('a aexp) ('a aexp)
  8172             | DIFF ('a aexp) ('a aexp)
  8173             | NUM 'a
  8174   and
  8175     'a bexp = LESS ('a aexp) ('a aexp)
  8176             | AND ('a bexp) ('a bexp)
  8177             | OR ('a bexp) ('a bexp)
  8178 
  8179 as well as indirectly recursive datatypes such as
  8180 
  8181   datatype
  8182     ('a, 'b) term = Var 'a
  8183                   | App 'b ((('a, 'b) term) list)
  8184 
  8185 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  8186 induction on mutually / indirectly recursive datatypes.
  8187 
  8188 Primrec equations are now stored in theory and can be accessed via
  8189 <function_name>.simps.
  8190 
  8191 INCOMPATIBILITIES:
  8192 
  8193   - Theories using datatypes must now have theory Datatype as an
  8194     ancestor.
  8195   - The specific <typename>.induct_tac no longer exists - use the
  8196     generic induct_tac instead.
  8197   - natE has been renamed to nat.exhaust - use exhaust_tac
  8198     instead of res_inst_tac ... natE. Note that the variable
  8199     names in nat.exhaust differ from the names in natE, this
  8200     may cause some "fragile" proofs to fail.
  8201   - The theorems split_<typename>_case and split_<typename>_case_asm
  8202     have been renamed to <typename>.split and <typename>.split_asm.
  8203   - Since default sorts of type variables are now handled correctly,
  8204     some datatype definitions may have to be annotated with explicit
  8205     sort constraints.
  8206   - Primrec definitions no longer require function name and type
  8207     of recursive argument.
  8208 
  8209 Consider using isatool fixdatatype to adapt your theories and proof
  8210 scripts to the new package (backup your sources first!).
  8211 
  8212 
  8213 * HOL/record package: considerably improved implementation; now
  8214 includes concrete syntax for record types, terms, updates; theorems
  8215 for surjective pairing and splitting !!-bound record variables; proof
  8216 support is as follows:
  8217 
  8218   1) standard conversions (selectors or updates applied to record
  8219 constructor terms) are part of the standard simpset;
  8220 
  8221   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  8222 made part of standard simpset and claset via addIffs;
  8223 
  8224   3) a tactic for record field splitting (record_split_tac) is part of
  8225 the standard claset (addSWrapper);
  8226 
  8227 To get a better idea about these rules you may retrieve them via
  8228 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  8229 the name of your record type.
  8230 
  8231 The split tactic 3) conceptually simplifies by the following rule:
  8232 
  8233   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  8234 
  8235 Thus any record variable that is bound by meta-all will automatically
  8236 blow up into some record constructor term, consequently the
  8237 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  8238 solve record problems automatically.
  8239 
  8240 
  8241 * reorganized the main HOL image: HOL/Integ and String loaded by
  8242 default; theory Main includes everything;
  8243 
  8244 * automatic simplification of integer sums and comparisons, using cancellation;
  8245 
  8246 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  8247 
  8248 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  8249 
  8250 * many new identities for unions, intersections, set difference, etc.;
  8251 
  8252 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  8253 called split_if, split_split, split_sum_case and split_nat_case (to go
  8254 with add/delsplits);
  8255 
  8256 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  8257 (?x::unit) = (); this is made part of the default simpset, which COULD
  8258 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  8259 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  8260 unit_abs_eta_conv is added in order to counter the effect of
  8261 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  8262 %u.f();
  8263 
  8264 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  8265 makes more sense);
  8266 
  8267 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  8268   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  8269   disjointness reasoning but breaking a few old proofs.
  8270 
  8271 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  8272 to 'converse' from 'inverse' (for compatibility with ZF and some
  8273 literature);
  8274 
  8275 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  8276 the well-founded relation;
  8277 
  8278 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  8279     Compl A.  The "Compl" syntax remains available as input syntax for this
  8280     release ONLY.
  8281 
  8282 * HOL/Update: new theory of function updates:
  8283     f(a:=b) == %x. if x=a then b else f x
  8284 may also be iterated as in f(a:=b,c:=d,...);
  8285 
  8286 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  8287 
  8288 * HOL/List:
  8289   - new function list_update written xs[i:=v] that updates the i-th
  8290     list position. May also be iterated as in xs[i:=a,j:=b,...].
  8291   - new function `upt' written [i..j(] which generates the list
  8292     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  8293     bound write [i..j], which is a shorthand for [i..j+1(].
  8294   - new lexicographic orderings and corresponding wellfoundedness theorems.
  8295 
  8296 * HOL/Arith:
  8297   - removed 'pred' (predecessor) function;
  8298   - generalized some theorems about n-1;
  8299   - many new laws about "div" and "mod";
  8300   - new laws about greatest common divisors (see theory ex/Primes);
  8301 
  8302 * HOL/Relation: renamed the relational operator r^-1 "converse"
  8303 instead of "inverse";
  8304 
  8305 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  8306   of the multiset ordering;
  8307 
  8308 * directory HOL/Real: a construction of the reals using Dedekind cuts
  8309   (not included by default);
  8310 
  8311 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  8312 
  8313 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  8314   programs, i.e. different program variables may have different types.
  8315 
  8316 * calling (stac rew i) now fails if "rew" has no effect on the goal
  8317   [previously, this check worked only if the rewrite rule was unconditional]
  8318   Now rew can involve either definitions or equalities (either == or =).
  8319 
  8320 
  8321 *** ZF ***
  8322 
  8323 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  8324   only the theorems proved on ZF.ML;
  8325 
  8326 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  8327   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  8328   disjointness reasoning but breaking a few old proofs.
  8329 
  8330 * ZF/Update: new theory of function updates
  8331     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  8332   may also be iterated as in f(a:=b,c:=d,...);
  8333 
  8334 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  8335 
  8336 * calling (stac rew i) now fails if "rew" has no effect on the goal
  8337   [previously, this check worked only if the rewrite rule was unconditional]
  8338   Now rew can involve either definitions or equalities (either == or =).
  8339 
  8340 * case_tac provided for compatibility with HOL
  8341     (like the old excluded_middle_tac, but with subgoals swapped)
  8342 
  8343 
  8344 *** Internal programming interfaces ***
  8345 
  8346 * Pure: several new basic modules made available for general use, see
  8347 also src/Pure/README;
  8348 
  8349 * improved the theory data mechanism to support encapsulation (data
  8350 kind name replaced by private Object.kind, acting as authorization
  8351 key); new type-safe user interface via functor TheoryDataFun; generic
  8352 print_data function becomes basically useless;
  8353 
  8354 * removed global_names compatibility flag -- all theory declarations
  8355 are qualified by default;
  8356 
  8357 * module Pure/Syntax now offers quote / antiquote translation
  8358 functions (useful for Hoare logic etc. with implicit dependencies);
  8359 see HOL/ex/Antiquote for an example use;
  8360 
  8361 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  8362 cterm -> thm;
  8363 
  8364 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  8365 subgoal;
  8366 
  8367 * Display.print_goals function moved to Locale.print_goals;
  8368 
  8369 * standard print function for goals supports current_goals_markers
  8370 variable for marking begin of proof, end of proof, start of goal; the
  8371 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  8372 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  8373 for example;
  8374 
  8375 
  8376 
  8377 New in Isabelle98 (January 1998)
  8378 --------------------------------
  8379 
  8380 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  8381 
  8382 * changed lexical syntax of terms / types: dots made part of long
  8383 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  8384 
  8385 * simpset (and claset) reference variable replaced by functions
  8386 simpset / simpset_ref;
  8387 
  8388 * no longer supports theory aliases (via merge) and non-trivial
  8389 implicit merge of thms' signatures;
  8390 
  8391 * most internal names of constants changed due to qualified names;
  8392 
  8393 * changed Pure/Sequence interface (see Pure/seq.ML);
  8394 
  8395 
  8396 *** General Changes ***
  8397 
  8398 * hierachically structured name spaces (for consts, types, axms, thms
  8399 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  8400 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  8401 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  8402 long_names for fully qualified output names; NOTE: ML programs
  8403 (special tactics, packages etc.) referring to internal names may have
  8404 to be adapted to cope with fully qualified names; in case of severe
  8405 backward campatibility problems try setting 'global_names' at compile
  8406 time to have enrything declared within a flat name space; one may also
  8407 fine tune name declarations in theories via the 'global' and 'local'
  8408 section;
  8409 
  8410 * reimplemented the implicit simpset and claset using the new anytype
  8411 data filed in signatures; references simpset:simpset ref etc. are
  8412 replaced by functions simpset:unit->simpset and
  8413 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  8414 to patch your ML files accordingly;
  8415 
  8416 * HTML output now includes theory graph data for display with Java
  8417 applet or isatool browser; data generated automatically via isatool
  8418 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  8419 
  8420 * defs may now be conditional; improved rewrite_goals_tac to handle
  8421 conditional equations;
  8422 
  8423 * defs now admits additional type arguments, using TYPE('a) syntax;
  8424 
  8425 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  8426 creates a new theory node; implicit merge of thms' signatures is
  8427 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  8428 transfer:theory->thm->thm in (rare) cases;
  8429 
  8430 * improved handling of draft signatures / theories; draft thms (and
  8431 ctyps, cterms) are automatically promoted to real ones;
  8432 
  8433 * slightly changed interfaces for oracles: admit many per theory, named
  8434 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  8435 
  8436 * print_goals: optional output of const types (set show_consts and
  8437 show_types);
  8438 
  8439 * improved output of warnings (###) and errors (***);
  8440 
  8441 * subgoal_tac displays a warning if the new subgoal has type variables;
  8442 
  8443 * removed old README and Makefiles;
  8444 
  8445 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  8446 
  8447 * removed obsolete init_pps and init_database;
  8448 
  8449 * deleted the obsolete tactical STATE, which was declared by
  8450     fun STATE tacfun st = tacfun st st;
  8451 
  8452 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  8453 (which abbreviates $HOME);
  8454 
  8455 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  8456 use isatool fixseq to adapt your ML programs (this works for fully
  8457 qualified references to the Sequence structure only!);
  8458 
  8459 * use_thy no longer requires writable current directory; it always
  8460 reloads .ML *and* .thy file, if either one is out of date;
  8461 
  8462 
  8463 *** Classical Reasoner ***
  8464 
  8465 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  8466 tactics that use classical reasoning to simplify a subgoal without
  8467 splitting it into several subgoals;
  8468 
  8469 * Safe_tac: like safe_tac but uses the default claset;
  8470 
  8471 
  8472 *** Simplifier ***
  8473 
  8474 * added simplification meta rules:
  8475     (asm_)(full_)simplify: simpset -> thm -> thm;
  8476 
  8477 * simplifier.ML no longer part of Pure -- has to be loaded by object
  8478 logics (again);
  8479 
  8480 * added prems argument to simplification procedures;
  8481 
  8482 * HOL, FOL, ZF: added infix function `addsplits':
  8483   instead of `<simpset> setloop (split_tac <thms>)'
  8484   you can simply write `<simpset> addsplits <thms>'
  8485 
  8486 
  8487 *** Syntax ***
  8488 
  8489 * TYPE('a) syntax for type reflection terms;
  8490 
  8491 * no longer handles consts with name "" -- declare as 'syntax' instead;
  8492 
  8493 * pretty printer: changed order of mixfix annotation preference (again!);
  8494 
  8495 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  8496 
  8497 
  8498 *** HOL ***
  8499 
  8500 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  8501   with `addloop' of the simplifier to faciliate case splitting in premises.
  8502 
  8503 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  8504 
  8505 * HOL/Auth: new protocol proofs including some for the Internet
  8506   protocol TLS;
  8507 
  8508 * HOL/Map: new theory of `maps' a la VDM;
  8509 
  8510 * HOL/simplifier: simplification procedures nat_cancel_sums for
  8511 cancelling out common nat summands from =, <, <= (in)equalities, or
  8512 differences; simplification procedures nat_cancel_factor for
  8513 cancelling common factor from =, <, <= (in)equalities over natural
  8514 sums; nat_cancel contains both kinds of procedures, it is installed by
  8515 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  8516 
  8517 * HOL/simplifier: terms of the form
  8518   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  8519   are rewritten to
  8520   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  8521   and those of the form
  8522   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  8523   are rewritten to
  8524   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  8525 
  8526 * HOL/datatype
  8527   Each datatype `t' now comes with a theorem `split_t_case' of the form
  8528 
  8529   P(t_case f1 ... fn x) =
  8530      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  8531         ...
  8532        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  8533      )
  8534 
  8535   and a theorem `split_t_case_asm' of the form
  8536 
  8537   P(t_case f1 ... fn x) =
  8538     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  8539         ...
  8540        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  8541      )
  8542   which can be added to a simpset via `addsplits'. The existing theorems
  8543   expand_list_case and expand_option_case have been renamed to
  8544   split_list_case and split_option_case.
  8545 
  8546 * HOL/Arithmetic:
  8547   - `pred n' is automatically converted to `n-1'.
  8548     Users are strongly encouraged not to use `pred' any longer,
  8549     because it will disappear altogether at some point.
  8550   - Users are strongly encouraged to write "0 < n" rather than
  8551     "n ~= 0". Theorems and proof tools have been modified towards this
  8552     `standard'.
  8553 
  8554 * HOL/Lists:
  8555   the function "set_of_list" has been renamed "set" (and its theorems too);
  8556   the function "nth" now takes its arguments in the reverse order and
  8557   has acquired the infix notation "!" as in "xs!n".
  8558 
  8559 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  8560 
  8561 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  8562   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  8563 
  8564 * HOL/record: extensible records with schematic structural subtyping
  8565 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  8566 still lacks various theorems and concrete record syntax;
  8567 
  8568 
  8569 *** HOLCF ***
  8570 
  8571 * removed "axioms" and "generated by" sections;
  8572 
  8573 * replaced "ops" section by extended "consts" section, which is capable of
  8574   handling the continuous function space "->" directly;
  8575 
  8576 * domain package:
  8577   . proves theorems immediately and stores them in the theory,
  8578   . creates hierachical name space,
  8579   . now uses normal mixfix annotations (instead of cinfix...),
  8580   . minor changes to some names and values (for consistency),
  8581   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  8582   . separator between mutual domain defs: changed "," to "and",
  8583   . improved handling of sort constraints;  now they have to
  8584     appear on the left-hand side of the equations only;
  8585 
  8586 * fixed LAM <x,y,zs>.b syntax;
  8587 
  8588 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  8589 adm (%x. P (t x)), where P is chainfinite and t continuous;
  8590 
  8591 
  8592 *** FOL and ZF ***
  8593 
  8594 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  8595   with `addloop' of the simplifier to faciliate case splitting in premises.
  8596 
  8597 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  8598 in HOL, they strip ALL and --> from proved theorems;
  8599 
  8600 
  8601 
  8602 New in Isabelle94-8 (May 1997)
  8603 ------------------------------
  8604 
  8605 *** General Changes ***
  8606 
  8607 * new utilities to build / run / maintain Isabelle etc. (in parts
  8608 still somewhat experimental); old Makefiles etc. still functional;
  8609 
  8610 * new 'Isabelle System Manual';
  8611 
  8612 * INSTALL text, together with ./configure and ./build scripts;
  8613 
  8614 * reimplemented type inference for greater efficiency, better error
  8615 messages and clean internal interface;
  8616 
  8617 * prlim command for dealing with lots of subgoals (an easier way of
  8618 setting goals_limit);
  8619 
  8620 
  8621 *** Syntax ***
  8622 
  8623 * supports alternative (named) syntax tables (parser and pretty
  8624 printer); internal interface is provided by add_modesyntax(_i);
  8625 
  8626 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  8627 be used in conjunction with the Isabelle symbol font; uses the
  8628 "symbols" syntax table;
  8629 
  8630 * added token_translation interface (may translate name tokens in
  8631 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  8632 the current print_mode); IMPORTANT: user print translation functions
  8633 are responsible for marking newly introduced bounds
  8634 (Syntax.mark_boundT);
  8635 
  8636 * token translations for modes "xterm" and "xterm_color" that display
  8637 names in bold, underline etc. or colors (which requires a color
  8638 version of xterm);
  8639 
  8640 * infixes may now be declared with names independent of their syntax;
  8641 
  8642 * added typed_print_translation (like print_translation, but may
  8643 access type of constant);
  8644 
  8645 
  8646 *** Classical Reasoner ***
  8647 
  8648 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  8649 some limitations.  Blast_tac...
  8650   + ignores addss, addbefore, addafter; this restriction is intrinsic
  8651   + ignores elimination rules that don't have the correct format
  8652         (the conclusion MUST be a formula variable)
  8653   + ignores types, which can make HOL proofs fail
  8654   + rules must not require higher-order unification, e.g. apply_type in ZF
  8655     [message "Function Var's argument not a bound variable" relates to this]
  8656   + its proof strategy is more general but can actually be slower
  8657 
  8658 * substitution with equality assumptions no longer permutes other
  8659 assumptions;
  8660 
  8661 * minor changes in semantics of addafter (now called addaltern); renamed
  8662 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  8663 (and access functions for it);
  8664 
  8665 * improved combination of classical reasoner and simplifier:
  8666   + functions for handling clasimpsets
  8667   + improvement of addss: now the simplifier is called _after_ the
  8668     safe steps.
  8669   + safe variant of addss called addSss: uses safe simplifications
  8670     _during_ the safe steps. It is more complete as it allows multiple
  8671     instantiations of unknowns (e.g. with slow_tac).
  8672 
  8673 *** Simplifier ***
  8674 
  8675 * added interface for simplification procedures (functions that
  8676 produce *proven* rewrite rules on the fly, depending on current
  8677 redex);
  8678 
  8679 * ordering on terms as parameter (used for ordered rewriting);
  8680 
  8681 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  8682 
  8683 * the solver is now split into a safe and an unsafe part.
  8684 This should be invisible for the normal user, except that the
  8685 functions setsolver and addsolver have been renamed to setSolver and
  8686 addSolver; added safe_asm_full_simp_tac;
  8687 
  8688 
  8689 *** HOL ***
  8690 
  8691 * a generic induction tactic `induct_tac' which works for all datatypes and
  8692 also for type `nat';
  8693 
  8694 * a generic case distinction tactic `exhaust_tac' which works for all
  8695 datatypes and also for type `nat';
  8696 
  8697 * each datatype comes with a function `size';
  8698 
  8699 * patterns in case expressions allow tuple patterns as arguments to
  8700 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  8701 
  8702 * primrec now also works with type nat;
  8703 
  8704 * recdef: a new declaration form, allows general recursive functions to be
  8705 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  8706 
  8707 * the constant for negation has been renamed from "not" to "Not" to
  8708 harmonize with FOL, ZF, LK, etc.;
  8709 
  8710 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  8711 infinite lists;
  8712 
  8713 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  8714 
  8715 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  8716 problems in commutative rings, using axiomatic type classes for + and *;
  8717 
  8718 * more examples in HOL/MiniML and HOL/Auth;
  8719 
  8720 * more default rewrite rules for quantifiers, union/intersection;
  8721 
  8722 * a new constant `arbitrary == @x.False';
  8723 
  8724 * HOLCF/IOA replaces old HOL/IOA;
  8725 
  8726 * HOLCF changes: derived all rules and arities
  8727   + axiomatic type classes instead of classes
  8728   + typedef instead of faking type definitions
  8729   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  8730   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  8731   + eliminated the types void, one, tr
  8732   + use unit lift and bool lift (with translations) instead of one and tr
  8733   + eliminated blift from Lift3.thy (use Def instead of blift)
  8734   all eliminated rules are derived as theorems --> no visible changes ;
  8735 
  8736 
  8737 *** ZF ***
  8738 
  8739 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  8740 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  8741 as ZF_cs addSIs [equalityI];
  8742 
  8743 
  8744 
  8745 New in Isabelle94-7 (November 96)
  8746 ---------------------------------
  8747 
  8748 * allowing negative levels (as offsets) in prlev and choplev;
  8749 
  8750 * super-linear speedup for large simplifications;
  8751 
  8752 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  8753 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  8754 FAIL); can suppress it using the command Delsimps (ex_simps @
  8755 all_simps); De Morgan laws are also now included, by default;
  8756 
  8757 * improved printing of ==>  :  ~:
  8758 
  8759 * new object-logic "Sequents" adds linear logic, while replacing LK
  8760 and Modal (thanks to Sara Kalvala);
  8761 
  8762 * HOL/Auth: correctness proofs for authentication protocols;
  8763 
  8764 * HOL: new auto_tac combines rewriting and classical reasoning (many
  8765 examples on HOL/Auth);
  8766 
  8767 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  8768 the rewriter and classical reasoner simultaneously;
  8769 
  8770 * function uresult no longer returns theorems in "standard" format;
  8771 regain previous version by: val uresult = standard o uresult;
  8772 
  8773 
  8774 
  8775 New in Isabelle94-6
  8776 -------------------
  8777 
  8778 * oracles -- these establish an interface between Isabelle and trusted
  8779 external reasoners, which may deliver results as theorems;
  8780 
  8781 * proof objects (in particular record all uses of oracles);
  8782 
  8783 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  8784 
  8785 * "constdefs" section in theory files;
  8786 
  8787 * "primrec" section (HOL) no longer requires names;
  8788 
  8789 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  8790 
  8791 
  8792 
  8793 New in Isabelle94-5
  8794 -------------------
  8795 
  8796 * reduced space requirements;
  8797 
  8798 * automatic HTML generation from theories;
  8799 
  8800 * theory files no longer require "..." (quotes) around most types;
  8801 
  8802 * new examples, including two proofs of the Church-Rosser theorem;
  8803 
  8804 * non-curried (1994) version of HOL is no longer distributed;
  8805 
  8806 
  8807 
  8808 New in Isabelle94-4
  8809 -------------------
  8810 
  8811 * greatly reduced space requirements;
  8812 
  8813 * theory files (.thy) no longer require \...\ escapes at line breaks;
  8814 
  8815 * searchable theorem database (see the section "Retrieving theorems" on
  8816 page 8 of the Reference Manual);
  8817 
  8818 * new examples, including Grabczewski's monumental case study of the
  8819 Axiom of Choice;
  8820 
  8821 * The previous version of HOL renamed to Old_HOL;
  8822 
  8823 * The new version of HOL (previously called CHOL) uses a curried syntax
  8824 for functions.  Application looks like f a b instead of f(a,b);
  8825 
  8826 * Mutually recursive inductive definitions finally work in HOL;
  8827 
  8828 * In ZF, pattern-matching on tuples is now available in all abstractions and
  8829 translates to the operator "split";
  8830 
  8831 
  8832 
  8833 New in Isabelle94-3
  8834 -------------------
  8835 
  8836 * new infix operator, addss, allowing the classical reasoner to
  8837 perform simplification at each step of its search.  Example:
  8838         fast_tac (cs addss ss)
  8839 
  8840 * a new logic, CHOL, the same as HOL, but with a curried syntax
  8841 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  8842 look like (a,b) instead of <a,b>;
  8843 
  8844 * PLEASE NOTE: CHOL will eventually replace HOL!
  8845 
  8846 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  8847 It translates to the operator "split".  A new theory of integers is available;
  8848 
  8849 * In ZF, integer numerals now denote two's-complement binary integers.
  8850 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  8851 
  8852 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  8853 of the Axiom of Choice;
  8854 
  8855 
  8856 
  8857 New in Isabelle94-2
  8858 -------------------
  8859 
  8860 * Significantly faster resolution;
  8861 
  8862 * the different sections in a .thy file can now be mixed and repeated
  8863 freely;
  8864 
  8865 * Database of theorems for FOL, HOL and ZF.  New
  8866 commands including qed, qed_goal and bind_thm store theorems in the database.
  8867 
  8868 * Simple database queries: return a named theorem (get_thm) or all theorems of
  8869 a given theory (thms_of), or find out what theory a theorem was proved in
  8870 (theory_of_thm);
  8871 
  8872 * Bugs fixed in the inductive definition and datatype packages;
  8873 
  8874 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  8875 and HOL_dup_cs obsolete;
  8876 
  8877 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  8878 have been removed;
  8879 
  8880 * Simpler definition of function space in ZF;
  8881 
  8882 * new results about cardinal and ordinal arithmetic in ZF;
  8883 
  8884 * 'subtype' facility in HOL for introducing new types as subsets of existing
  8885 types;
  8886 
  8887 :mode=text:wrap=hard:maxLineLen=72: