src/HOL/Tools/Nitpick/nitpick.ML
author wenzelm
Fri Sep 14 18:12:41 2012 +0200 (2012-09-14 ago)
changeset 49358 0fa351b1bd14
parent 49024 224a0c63ba23
child 50163 c62ce309dc26
permissions -rw-r--r--
clarified markup names;
     1 (*  Title:      HOL/Tools/Nitpick/nitpick.ML
     2     Author:     Jasmin Blanchette, TU Muenchen
     3     Copyright   2008, 2009, 2010
     4 
     5 Finite model generation for HOL formulas using Kodkod.
     6 *)
     7 
     8 signature NITPICK =
     9 sig
    10   type styp = Nitpick_Util.styp
    11   type term_postprocessor = Nitpick_Model.term_postprocessor
    12 
    13   datatype mode = Auto_Try | Try | Normal | TPTP
    14 
    15   type params =
    16     {cards_assigns: (typ option * int list) list,
    17      maxes_assigns: (styp option * int list) list,
    18      iters_assigns: (styp option * int list) list,
    19      bitss: int list,
    20      bisim_depths: int list,
    21      boxes: (typ option * bool option) list,
    22      finitizes: (typ option * bool option) list,
    23      monos: (typ option * bool option) list,
    24      stds: (typ option * bool) list,
    25      wfs: (styp option * bool option) list,
    26      sat_solver: string,
    27      blocking: bool,
    28      falsify: bool,
    29      debug: bool,
    30      verbose: bool,
    31      overlord: bool,
    32      user_axioms: bool option,
    33      assms: bool,
    34      whacks: term list,
    35      merge_type_vars: bool,
    36      binary_ints: bool option,
    37      destroy_constrs: bool,
    38      specialize: bool,
    39      star_linear_preds: bool,
    40      total_consts: bool option,
    41      needs: term list option,
    42      peephole_optim: bool,
    43      datatype_sym_break: int,
    44      kodkod_sym_break: int,
    45      timeout: Time.time option,
    46      tac_timeout: Time.time option,
    47      max_threads: int,
    48      show_datatypes: bool,
    49      show_skolems: bool,
    50      show_consts: bool,
    51      evals: term list,
    52      formats: (term option * int list) list,
    53      atomss: (typ option * string list) list,
    54      max_potential: int,
    55      max_genuine: int,
    56      check_potential: bool,
    57      check_genuine: bool,
    58      batch_size: int,
    59      expect: string}
    60 
    61   val genuineN : string
    62   val quasi_genuineN : string
    63   val potentialN : string
    64   val noneN : string
    65   val unknownN : string
    66   val register_frac_type : string -> (string * string) list -> theory -> theory
    67   val unregister_frac_type : string -> theory -> theory
    68   val register_codatatype : typ -> string -> styp list -> theory -> theory
    69   val unregister_codatatype : typ -> theory -> theory
    70   val register_term_postprocessor :
    71     typ -> term_postprocessor -> theory -> theory
    72   val unregister_term_postprocessor : typ -> theory -> theory
    73   val pick_nits_in_term :
    74     Proof.state -> params -> mode -> int -> int -> int -> (term * term) list
    75     -> term list -> term list -> term -> string * Proof.state
    76   val pick_nits_in_subgoal :
    77     Proof.state -> params -> mode -> int -> int -> string * Proof.state
    78 end;
    79 
    80 structure Nitpick : NITPICK =
    81 struct
    82 
    83 open Nitpick_Util
    84 open Nitpick_HOL
    85 open Nitpick_Preproc
    86 open Nitpick_Mono
    87 open Nitpick_Scope
    88 open Nitpick_Peephole
    89 open Nitpick_Rep
    90 open Nitpick_Nut
    91 open Nitpick_Kodkod
    92 open Nitpick_Model
    93 
    94 structure KK = Kodkod
    95 
    96 datatype mode = Auto_Try | Try | Normal | TPTP
    97 
    98 fun is_mode_nt mode = (mode = Normal orelse mode = TPTP)
    99 
   100 type params =
   101   {cards_assigns: (typ option * int list) list,
   102    maxes_assigns: (styp option * int list) list,
   103    iters_assigns: (styp option * int list) list,
   104    bitss: int list,
   105    bisim_depths: int list,
   106    boxes: (typ option * bool option) list,
   107    finitizes: (typ option * bool option) list,
   108    monos: (typ option * bool option) list,
   109    stds: (typ option * bool) list,
   110    wfs: (styp option * bool option) list,
   111    sat_solver: string,
   112    blocking: bool,
   113    falsify: bool,
   114    debug: bool,
   115    verbose: bool,
   116    overlord: bool,
   117    user_axioms: bool option,
   118    assms: bool,
   119    whacks: term list,
   120    merge_type_vars: bool,
   121    binary_ints: bool option,
   122    destroy_constrs: bool,
   123    specialize: bool,
   124    star_linear_preds: bool,
   125    total_consts: bool option,
   126    needs: term list option,
   127    peephole_optim: bool,
   128    datatype_sym_break: int,
   129    kodkod_sym_break: int,
   130    timeout: Time.time option,
   131    tac_timeout: Time.time option,
   132    max_threads: int,
   133    show_datatypes: bool,
   134    show_skolems: bool,
   135    show_consts: bool,
   136    evals: term list,
   137    formats: (term option * int list) list,
   138    atomss: (typ option * string list) list,
   139    max_potential: int,
   140    max_genuine: int,
   141    check_potential: bool,
   142    check_genuine: bool,
   143    batch_size: int,
   144    expect: string}
   145 
   146 val genuineN = "genuine"
   147 val quasi_genuineN = "quasi_genuine"
   148 val potentialN = "potential"
   149 val noneN = "none"
   150 val unknownN = "unknown"
   151 
   152 (* TODO: eliminate these historical aliases *)
   153 val register_frac_type = Nitpick_HOL.register_frac_type_global
   154 val unregister_frac_type = Nitpick_HOL.unregister_frac_type_global
   155 val register_codatatype = Nitpick_HOL.register_codatatype_global
   156 val unregister_codatatype = Nitpick_HOL.unregister_codatatype_global
   157 val register_term_postprocessor =
   158   Nitpick_Model.register_term_postprocessor_global
   159 val unregister_term_postprocessor =
   160   Nitpick_Model.unregister_term_postprocessor_global
   161 
   162 type problem_extension =
   163   {free_names: nut list,
   164    sel_names: nut list,
   165    nonsel_names: nut list,
   166    rel_table: nut NameTable.table,
   167    unsound: bool,
   168    scope: scope}
   169 
   170 type rich_problem = KK.problem * problem_extension
   171 
   172 fun pretties_for_formulas _ _ [] = []
   173   | pretties_for_formulas ctxt s ts =
   174     [Pretty.str (s ^ plural_s_for_list ts ^ ":"),
   175      Pretty.indent indent_size (Pretty.chunks
   176          (map2 (fn j => fn t =>
   177                    Pretty.block [t |> shorten_names_in_term
   178                                    |> Syntax.pretty_term ctxt,
   179                                  Pretty.str (if j = 1 then "." else ";")])
   180                (length ts downto 1) ts))]
   181 
   182 val isabelle_wrong_message =
   183   "Something appears to be wrong with your Isabelle installation."
   184 fun java_not_found_message () =
   185   "Java could not be launched. " ^ isabelle_wrong_message
   186 fun java_too_old_message () =
   187   "The Java version is too old. " ^ isabelle_wrong_message
   188 fun kodkodi_not_installed_message () =
   189   "Nitpick requires the external Java program Kodkodi. To install it, download \
   190   \the package from \"http://www21.in.tum.de/~blanchet/#software\" and add the \
   191   \\"kodkodi-x.y.z\" directory's full path to " ^
   192   Path.print (Path.expand (Path.explode "$ISABELLE_HOME_USER/etc/components")) ^
   193   " on a line of its own."
   194 
   195 val max_unsound_delay_ms = 200
   196 val max_unsound_delay_percent = 2
   197 
   198 fun unsound_delay_for_timeout NONE = max_unsound_delay_ms
   199   | unsound_delay_for_timeout (SOME timeout) =
   200     Int.max (0, Int.min (max_unsound_delay_ms,
   201                          Time.toMilliseconds timeout
   202                          * max_unsound_delay_percent div 100))
   203 
   204 fun passed_deadline NONE = false
   205   | passed_deadline (SOME time) = Time.compare (Time.now (), time) <> LESS
   206 
   207 fun none_true assigns = forall (not_equal (SOME true) o snd) assigns
   208 
   209 fun has_lonely_bool_var (@{const Pure.conjunction}
   210                          $ (@{const Trueprop} $ Free _) $ _) = true
   211   | has_lonely_bool_var _ = false
   212 
   213 val syntactic_sorts =
   214   @{sort "{default,zero,one,plus,minus,uminus,times,inverse,abs,sgn,ord,equal}"} @
   215   @{sort numeral}
   216 fun has_tfree_syntactic_sort (TFree (_, S as _ :: _)) =
   217     subset (op =) (S, syntactic_sorts)
   218   | has_tfree_syntactic_sort _ = false
   219 val has_syntactic_sorts = exists_type (exists_subtype has_tfree_syntactic_sort)
   220 
   221 fun plazy f = Pretty.blk (0, pstrs (f ()))
   222 
   223 fun pick_them_nits_in_term deadline state (params : params) mode i n step
   224                            subst def_assm_ts nondef_assm_ts orig_t =
   225   let
   226     val timer = Timer.startRealTimer ()
   227     val thy = Proof.theory_of state
   228     val ctxt = Proof.context_of state
   229 (* FIXME: reintroduce code before new release:
   230 
   231     val nitpick_thy = Thy_Info.get_theory "Nitpick"
   232     val _ = Theory.subthy (nitpick_thy, thy) orelse
   233             error "You must import the theory \"Nitpick\" to use Nitpick"
   234 *)
   235     val {cards_assigns, maxes_assigns, iters_assigns, bitss, bisim_depths,
   236          boxes, finitizes, monos, stds, wfs, sat_solver, falsify, debug,
   237          verbose, overlord, user_axioms, assms, whacks, merge_type_vars,
   238          binary_ints, destroy_constrs, specialize, star_linear_preds,
   239          total_consts, needs, peephole_optim, datatype_sym_break,
   240          kodkod_sym_break, tac_timeout, max_threads, show_datatypes,
   241          show_skolems, show_consts, evals, formats, atomss, max_potential,
   242          max_genuine, check_potential, check_genuine, batch_size, ...} = params
   243     val state_ref = Unsynchronized.ref state
   244     fun pprint print =
   245       if mode = Auto_Try then
   246         Unsynchronized.change state_ref o Proof.goal_message o K
   247         o Pretty.chunks o cons (Pretty.str "") o single
   248         o Pretty.mark Isabelle_Markup.intensify
   249       else
   250         print o Pretty.string_of
   251     val pprint_a = pprint Output.urgent_message
   252     fun pprint_nt f = () |> is_mode_nt mode ? pprint Output.urgent_message o f
   253     fun pprint_v f = () |> verbose ? pprint Output.urgent_message o f
   254     fun pprint_d f = () |> debug ? pprint tracing o f
   255     val print = pprint Output.urgent_message o curry Pretty.blk 0 o pstrs
   256     fun print_t f = () |> mode = TPTP ? print o f
   257 (*
   258     val print_g = pprint tracing o Pretty.str
   259 *)
   260     val print_nt = pprint_nt o K o plazy
   261     val print_v = pprint_v o K o plazy
   262 
   263     fun check_deadline () =
   264       if passed_deadline deadline then raise TimeLimit.TimeOut else ()
   265 
   266     val (def_assm_ts, nondef_assm_ts) =
   267       if assms orelse mode <> Normal then (def_assm_ts, nondef_assm_ts)
   268       else ([], [])
   269     val _ =
   270       if step = 0 then
   271         print_nt (fn () => "Nitpicking formula...")
   272       else
   273         pprint_nt (fn () => Pretty.chunks (
   274             pretties_for_formulas ctxt ("Nitpicking " ^
   275                 (if i <> 1 orelse n <> 1 then
   276                    "subgoal " ^ string_of_int i ^ " of " ^ string_of_int n
   277                  else
   278                    "goal")) [Logic.list_implies (nondef_assm_ts, orig_t)]))
   279     val _ = print_v (enclose "Timestamp: " "." o Date.fmt "%H:%M:%S"
   280                      o Date.fromTimeLocal o Time.now)
   281     val neg_t = if falsify then Logic.mk_implies (orig_t, @{prop False})
   282                 else orig_t
   283     val conj_ts = neg_t :: def_assm_ts @ nondef_assm_ts @ evals @ these needs
   284     val tfree_table =
   285       if merge_type_vars then merged_type_var_table_for_terms thy conj_ts
   286       else []
   287     val merge_tfrees = merge_type_vars_in_term thy merge_type_vars tfree_table
   288     val neg_t = neg_t |> merge_tfrees
   289     val def_assm_ts = def_assm_ts |> map merge_tfrees
   290     val nondef_assm_ts = nondef_assm_ts |> map merge_tfrees
   291     val evals = evals |> map merge_tfrees
   292     val needs = needs |> Option.map (map merge_tfrees)
   293     val conj_ts = neg_t :: def_assm_ts @ nondef_assm_ts @ evals @ these needs
   294     val original_max_potential = max_potential
   295     val original_max_genuine = max_genuine
   296     val max_bisim_depth = fold Integer.max bisim_depths ~1
   297     val case_names = case_const_names ctxt stds
   298     val defs = def_assm_ts @ all_defs_of thy subst
   299     val nondefs = all_nondefs_of ctxt subst
   300     val def_tables = const_def_tables ctxt subst defs
   301     val nondef_table = const_nondef_table nondefs
   302     val simp_table = Unsynchronized.ref (const_simp_table ctxt subst)
   303     val psimp_table = const_psimp_table ctxt subst
   304     val choice_spec_table = const_choice_spec_table ctxt subst
   305     val nondefs =
   306       nondefs |> filter_out (is_choice_spec_axiom thy choice_spec_table)
   307     val intro_table = inductive_intro_table ctxt subst def_tables
   308     val ground_thm_table = ground_theorem_table thy
   309     val ersatz_table = ersatz_table ctxt
   310     val hol_ctxt as {wf_cache, ...} =
   311       {thy = thy, ctxt = ctxt, max_bisim_depth = max_bisim_depth, boxes = boxes,
   312        stds = stds, wfs = wfs, user_axioms = user_axioms, debug = debug,
   313        whacks = whacks, binary_ints = binary_ints,
   314        destroy_constrs = destroy_constrs, specialize = specialize,
   315        star_linear_preds = star_linear_preds, total_consts = total_consts,
   316        needs = needs, tac_timeout = tac_timeout, evals = evals,
   317        case_names = case_names, def_tables = def_tables,
   318        nondef_table = nondef_table, nondefs = nondefs, simp_table = simp_table,
   319        psimp_table = psimp_table, choice_spec_table = choice_spec_table,
   320        intro_table = intro_table, ground_thm_table = ground_thm_table,
   321        ersatz_table = ersatz_table, skolems = Unsynchronized.ref [],
   322        special_funs = Unsynchronized.ref [],
   323        unrolled_preds = Unsynchronized.ref [], wf_cache = Unsynchronized.ref [],
   324        constr_cache = Unsynchronized.ref []}
   325     val pseudo_frees = []
   326     val real_frees = fold Term.add_frees conj_ts []
   327     val _ = null (fold Term.add_tvars conj_ts []) orelse
   328             error "Nitpick cannot handle goals with schematic type variables."
   329     val (nondef_ts, def_ts, need_ts, got_all_mono_user_axioms,
   330          no_poly_user_axioms, binarize) =
   331       preprocess_formulas hol_ctxt nondef_assm_ts neg_t
   332     val got_all_user_axioms =
   333       got_all_mono_user_axioms andalso no_poly_user_axioms
   334 
   335     fun print_wf (x, (gfp, wf)) =
   336       pprint_nt (fn () => Pretty.blk (0,
   337           pstrs ("The " ^ (if gfp then "co" else "") ^ "inductive predicate \"")
   338           @ Syntax.pretty_term ctxt (Const x) ::
   339           pstrs (if wf then
   340                    "\" was proved well-founded. Nitpick can compute it \
   341                    \efficiently."
   342                  else
   343                    "\" could not be proved well-founded. Nitpick might need to \
   344                    \unroll it.")))
   345     val _ = if verbose then List.app print_wf (!wf_cache) else ()
   346     val das_wort_formula = if falsify then "Negated conjecture" else "Formula"
   347     val _ =
   348       pprint_d (fn () => Pretty.chunks
   349           (pretties_for_formulas ctxt das_wort_formula [hd nondef_ts] @
   350            pretties_for_formulas ctxt "Relevant definitional axiom" def_ts @
   351            pretties_for_formulas ctxt "Relevant nondefinitional axiom"
   352                                  (tl nondef_ts)))
   353     val _ = List.app (ignore o Term.type_of) (nondef_ts @ def_ts)
   354             handle TYPE (_, Ts, ts) =>
   355                    raise TYPE ("Nitpick.pick_them_nits_in_term", Ts, ts)
   356 
   357     val nondef_us = nondef_ts |> map (nut_from_term hol_ctxt Eq)
   358     val def_us = def_ts |> map (nut_from_term hol_ctxt DefEq)
   359     val need_us = need_ts |> map (nut_from_term hol_ctxt Eq)
   360     val (free_names, const_names) =
   361       fold add_free_and_const_names (nondef_us @ def_us @ need_us) ([], [])
   362     val (sel_names, nonsel_names) =
   363       List.partition (is_sel o nickname_of) const_names
   364     val sound_finitizes = none_true finitizes
   365     val standard = forall snd stds
   366 (*
   367     val _ =
   368       List.app (print_g o string_for_nut ctxt) (nondef_us @ def_us @ need_us)
   369 *)
   370 
   371     val unique_scope = forall (curry (op =) 1 o length o snd) cards_assigns
   372     fun monotonicity_message Ts extra =
   373       let val pretties = map (pretty_maybe_quote o pretty_for_type ctxt) Ts in
   374         Pretty.blk (0,
   375           pstrs ("The type" ^ plural_s_for_list pretties ^ " ") @
   376           pretty_serial_commas "and" pretties @
   377           pstrs (" " ^
   378                  (if none_true monos then
   379                     "passed the monotonicity test"
   380                   else
   381                     (if length pretties = 1 then "is" else "are") ^
   382                     " considered monotonic") ^
   383                  ". " ^ extra))
   384       end
   385     fun is_type_fundamentally_monotonic T =
   386       (is_datatype ctxt stds T andalso not (is_quot_type ctxt T) andalso
   387        (not (is_pure_typedef ctxt T) orelse is_univ_typedef ctxt T)) orelse
   388       is_number_type ctxt T orelse is_bit_type T
   389     fun is_type_actually_monotonic T =
   390       time_limit tac_timeout (formulas_monotonic hol_ctxt binarize T)
   391                  (nondef_ts, def_ts)
   392       handle TimeLimit.TimeOut => false
   393     fun is_type_kind_of_monotonic T =
   394       case triple_lookup (type_match thy) monos T of
   395         SOME (SOME false) => false
   396       | _ => is_type_actually_monotonic T
   397     fun is_type_monotonic T =
   398       unique_scope orelse
   399       case triple_lookup (type_match thy) monos T of
   400         SOME (SOME b) => b
   401       | _ => is_type_fundamentally_monotonic T orelse
   402              is_type_actually_monotonic T
   403     fun is_deep_datatype_finitizable T =
   404       triple_lookup (type_match thy) finitizes T = SOME (SOME true)
   405     fun is_shallow_datatype_finitizable (T as Type (@{type_name fun_box}, _)) =
   406         is_type_kind_of_monotonic T
   407       | is_shallow_datatype_finitizable T =
   408         case triple_lookup (type_match thy) finitizes T of
   409           SOME (SOME b) => b
   410         | _ => is_type_kind_of_monotonic T
   411     fun is_datatype_deep T =
   412       not standard orelse T = @{typ unit} orelse T = nat_T orelse
   413       is_word_type T orelse
   414       exists (curry (op =) T o domain_type o type_of) sel_names
   415     val all_Ts = ground_types_in_terms hol_ctxt binarize (nondef_ts @ def_ts)
   416                  |> sort Term_Ord.typ_ord
   417     val _ =
   418       if verbose andalso binary_ints = SOME true andalso
   419          exists (member (op =) [nat_T, int_T]) all_Ts then
   420         print_v (K "The option \"binary_ints\" will be ignored because of the \
   421                    \presence of rationals, reals, \"Suc\", \"gcd\", or \"lcm\" \
   422                    \in the problem or because of the \"non_std\" option.")
   423       else
   424         ()
   425     val _ =
   426       if mode = Normal andalso
   427          exists (fn Type (@{type_name Datatype.node}, _) => true | _ => false)
   428                 all_Ts then
   429         print_nt (K ("Warning: The problem involves directly or indirectly the \
   430                      \internal type " ^ quote @{type_name Datatype.node} ^
   431                      ". This type is very Nitpick-unfriendly, and its presence \
   432                      \usually indicates either a failure of abstraction or a \
   433                      \quirk in Nitpick."))
   434       else
   435         ()
   436     val (mono_Ts, nonmono_Ts) = List.partition is_type_monotonic all_Ts
   437     val _ =
   438       if verbose andalso not unique_scope then
   439         case filter_out is_type_fundamentally_monotonic mono_Ts of
   440           [] => ()
   441         | interesting_mono_Ts =>
   442           pprint_v (K (monotonicity_message interesting_mono_Ts
   443                           "Nitpick might be able to skip some scopes."))
   444       else
   445         ()
   446     val (deep_dataTs, shallow_dataTs) =
   447       all_Ts |> filter (is_datatype ctxt stds)
   448              |> List.partition is_datatype_deep
   449     val finitizable_dataTs =
   450       (deep_dataTs |> filter_out (is_finite_type hol_ctxt)
   451                    |> filter is_deep_datatype_finitizable) @
   452       (shallow_dataTs |> filter_out (is_finite_type hol_ctxt)
   453                       |> filter is_shallow_datatype_finitizable)
   454     val _ =
   455       if verbose andalso not (null finitizable_dataTs) then
   456         pprint_v (K (monotonicity_message finitizable_dataTs
   457                          "Nitpick can use a more precise finite encoding."))
   458       else
   459         ()
   460     (* This detection code is an ugly hack. Fortunately, it is used only to
   461        provide a hint to the user. *)
   462     fun is_struct_induct_step (name, (Rule_Cases.Case {fixes, assumes, ...}, _)) =
   463       not (null fixes) andalso
   464       exists (String.isSuffix ".hyps" o fst) assumes andalso
   465       exists (exists (curry (op =) name o shortest_name o fst)
   466               o datatype_constrs hol_ctxt) deep_dataTs
   467     val likely_in_struct_induct_step =
   468       exists is_struct_induct_step (Proof_Context.cases_of ctxt)
   469     val _ = if standard andalso likely_in_struct_induct_step then
   470               pprint_nt (fn () => Pretty.blk (0,
   471                   pstrs "Hint: To check that the induction hypothesis is \
   472                         \general enough, try this command: " @
   473                   [Pretty.mark Isabelle_Markup.sendback (Pretty.blk (0,
   474                        pstrs ("nitpick [non_std, show_all]")))] @ pstrs "."))
   475             else
   476               ()
   477 (*
   478     val _ = print_g "Monotonic types:"
   479     val _ = List.app (print_g o string_for_type ctxt) mono_Ts
   480     val _ = print_g "Nonmonotonic types:"
   481     val _ = List.app (print_g o string_for_type ctxt) nonmono_Ts
   482 *)
   483 
   484     val incremental = Int.max (max_potential, max_genuine) >= 2
   485     val actual_sat_solver =
   486       if sat_solver <> "smart" then
   487         if incremental andalso
   488            not (member (op =) (Kodkod_SAT.configured_sat_solvers true)
   489                        sat_solver) then
   490           (print_nt (K ("An incremental SAT solver is required: \"SAT4J\" will \
   491                         \be used instead of " ^ quote sat_solver ^ "."));
   492            "SAT4J")
   493         else
   494           sat_solver
   495       else
   496         Kodkod_SAT.smart_sat_solver_name incremental
   497     val _ =
   498       if sat_solver = "smart" then
   499         print_v (fn () =>
   500             "Using SAT solver " ^ quote actual_sat_solver ^ ". The following" ^
   501             (if incremental then " incremental " else " ") ^
   502             "solvers are configured: " ^
   503             commas_quote (Kodkod_SAT.configured_sat_solvers incremental) ^ ".")
   504       else
   505         ()
   506 
   507     val too_big_scopes = Unsynchronized.ref []
   508 
   509     fun problem_for_scope unsound
   510             (scope as {card_assigns, bits, bisim_depth, datatypes, ofs, ...}) =
   511       let
   512         val _ = not (exists (fn other => scope_less_eq other scope)
   513                             (!too_big_scopes)) orelse
   514                 raise TOO_LARGE ("Nitpick.pick_them_nits_in_term.\
   515                                  \problem_for_scope", "too large scope")
   516 (*
   517         val _ = print_g "Offsets:"
   518         val _ = List.app (fn (T, j0) =>
   519                              print_g (string_for_type ctxt T ^ " = " ^
   520                                     string_of_int j0))
   521                          (Typtab.dest ofs)
   522 *)
   523         val effective_total_consts =
   524           case total_consts of
   525             SOME b => b
   526           | NONE => forall (is_exact_type datatypes true) all_Ts
   527         val main_j0 = offset_of_type ofs bool_T
   528         val (nat_card, nat_j0) = spec_of_type scope nat_T
   529         val (int_card, int_j0) = spec_of_type scope int_T
   530         val _ = (nat_j0 = main_j0 andalso int_j0 = main_j0) orelse
   531                 raise BAD ("Nitpick.pick_them_nits_in_term.problem_for_scope",
   532                            "bad offsets")
   533         val kk = kodkod_constrs peephole_optim nat_card int_card main_j0
   534         val (free_names, rep_table) =
   535           choose_reps_for_free_vars scope pseudo_frees free_names
   536                                     NameTable.empty
   537         val (sel_names, rep_table) = choose_reps_for_all_sels scope rep_table
   538         val (nonsel_names, rep_table) =
   539           choose_reps_for_consts scope effective_total_consts nonsel_names
   540                                  rep_table
   541         val (guiltiest_party, min_highest_arity) =
   542           NameTable.fold (fn (name, R) => fn (s, n) =>
   543                              let val n' = arity_of_rep R in
   544                                if n' > n then (nickname_of name, n') else (s, n)
   545                              end) rep_table ("", 1)
   546         val min_univ_card =
   547           NameTable.fold (Integer.max o min_univ_card_of_rep o snd) rep_table
   548                          (univ_card nat_card int_card main_j0 [] KK.True)
   549         val _ = if debug then ()
   550                 else check_arity guiltiest_party min_univ_card min_highest_arity
   551 
   552         val def_us =
   553           def_us |> map (choose_reps_in_nut scope unsound rep_table true)
   554         val nondef_us =
   555           nondef_us |> map (choose_reps_in_nut scope unsound rep_table false)
   556         val need_us =
   557           need_us |> map (choose_reps_in_nut scope unsound rep_table false)
   558 (*
   559         val _ = List.app (print_g o string_for_nut ctxt)
   560                          (free_names @ sel_names @ nonsel_names @
   561                           nondef_us @ def_us @ need_us)
   562 *)
   563         val (free_rels, pool, rel_table) =
   564           rename_free_vars free_names initial_pool NameTable.empty
   565         val (sel_rels, pool, rel_table) =
   566           rename_free_vars sel_names pool rel_table
   567         val (other_rels, pool, rel_table) =
   568           rename_free_vars nonsel_names pool rel_table
   569         val nondef_us = nondef_us |> map (rename_vars_in_nut pool rel_table)
   570         val def_us = def_us |> map (rename_vars_in_nut pool rel_table)
   571         val need_us = need_us |> map (rename_vars_in_nut pool rel_table)
   572         val nondef_fs = map (kodkod_formula_from_nut ofs kk) nondef_us
   573         val def_fs = map (kodkod_formula_from_nut ofs kk) def_us
   574         val formula = fold (fold s_and) [def_fs, nondef_fs] KK.True
   575         val comment = (if unsound then "unsound" else "sound") ^ "\n" ^
   576                       Print_Mode.setmp [] multiline_string_for_scope scope
   577         val kodkod_sat_solver =
   578           Kodkod_SAT.sat_solver_spec actual_sat_solver |> snd
   579         val bit_width = if bits = 0 then 16 else bits + 1
   580         val delay =
   581           if unsound then
   582             Option.map (fn time => Time.- (time, Time.now ())) deadline
   583             |> unsound_delay_for_timeout
   584           else
   585             0
   586         val settings = [("solver", commas_quote kodkod_sat_solver),
   587                         ("bit_width", string_of_int bit_width),
   588                         ("symmetry_breaking", string_of_int kodkod_sym_break),
   589                         ("sharing", "3"),
   590                         ("flatten", "false"),
   591                         ("delay", signed_string_of_int delay)]
   592         val plain_rels = free_rels @ other_rels
   593         val plain_bounds = map (bound_for_plain_rel ctxt debug) plain_rels
   594         val plain_axioms = map (declarative_axiom_for_plain_rel kk) plain_rels
   595         val need_vals =
   596           map (fn dtype as {typ, ...} =>
   597                   (typ, needed_values_for_datatype need_us ofs dtype)) datatypes
   598         val sel_bounds =
   599           map (bound_for_sel_rel ctxt debug need_vals datatypes) sel_rels
   600         val dtype_axioms =
   601           declarative_axioms_for_datatypes hol_ctxt binarize need_us need_vals
   602               datatype_sym_break bits ofs kk rel_table datatypes
   603         val declarative_axioms = plain_axioms @ dtype_axioms
   604         val univ_card = Int.max (univ_card nat_card int_card main_j0
   605                                      (plain_bounds @ sel_bounds) formula,
   606                                  main_j0 |> bits > 0 ? Integer.add (bits + 1))
   607         val (built_in_bounds, built_in_axioms) =
   608           bounds_and_axioms_for_built_in_rels_in_formulas debug univ_card
   609               nat_card int_card main_j0 (formula :: declarative_axioms)
   610         val bounds = built_in_bounds @ plain_bounds @ sel_bounds
   611                      |> not debug ? merge_bounds
   612         val axioms = built_in_axioms @ declarative_axioms
   613         val highest_arity =
   614           fold Integer.max (map (fst o fst) (maps fst bounds)) 0
   615         val formula = fold_rev s_and axioms formula
   616         val _ = if bits = 0 then () else check_bits bits formula
   617         val _ = if debug orelse formula = KK.False then ()
   618                 else check_arity "" univ_card highest_arity
   619       in
   620         SOME ({comment = comment, settings = settings, univ_card = univ_card,
   621                tuple_assigns = [], bounds = bounds,
   622                int_bounds = if bits = 0 then sequential_int_bounds univ_card
   623                             else pow_of_two_int_bounds bits main_j0,
   624                expr_assigns = [], formula = formula},
   625               {free_names = free_names, sel_names = sel_names,
   626                nonsel_names = nonsel_names, rel_table = rel_table,
   627                unsound = unsound, scope = scope})
   628       end
   629       handle TOO_LARGE (loc, msg) =>
   630              if loc = "Nitpick_Kodkod.check_arity" andalso
   631                 not (Typtab.is_empty ofs) then
   632                problem_for_scope unsound
   633                    {hol_ctxt = hol_ctxt, binarize = binarize,
   634                     card_assigns = card_assigns, bits = bits,
   635                     bisim_depth = bisim_depth, datatypes = datatypes,
   636                     ofs = Typtab.empty}
   637              else if loc = "Nitpick.pick_them_nits_in_term.\
   638                            \problem_for_scope" then
   639                NONE
   640              else
   641                (Unsynchronized.change too_big_scopes (cons scope);
   642                 print_v (fn () =>
   643                     "Limit reached: " ^ msg ^ ". Skipping " ^
   644                     (if unsound then "potential component of " else "") ^
   645                     "scope.");
   646                 NONE)
   647            | TOO_SMALL (_, msg) =>
   648              (print_v (fn () =>
   649                   "Limit reached: " ^ msg ^ ". Skipping " ^
   650                   (if unsound then "potential component of " else "") ^
   651                   "scope.");
   652               NONE)
   653 
   654     val das_wort_model =
   655       (if falsify then "counterexample" else "model")
   656       |> not standard ? prefix "nonstandard "
   657 
   658     val scopes = Unsynchronized.ref []
   659     val generated_scopes = Unsynchronized.ref []
   660     val generated_problems = Unsynchronized.ref ([] : rich_problem list)
   661     val checked_problems = Unsynchronized.ref (SOME [])
   662     val met_potential = Unsynchronized.ref 0
   663 
   664     fun update_checked_problems problems =
   665       List.app (Unsynchronized.change checked_problems o Option.map o cons
   666                 o nth problems)
   667     fun show_kodkod_warning "" = ()
   668       | show_kodkod_warning s = print_nt (fn () => "Kodkod warning: " ^ s ^ ".")
   669 
   670     fun print_and_check_model genuine bounds
   671             ({free_names, sel_names, nonsel_names, rel_table, scope, ...}
   672              : problem_extension) =
   673       let
   674         val _ =
   675           print_t (fn () =>
   676                "% SZS status " ^
   677                (if genuine then
   678                   if falsify then "CounterSatisfiable" else "Satisfiable"
   679                 else
   680                   "Unknown") ^ "\n" ^
   681                "% SZS output start FiniteModel")
   682         val (reconstructed_model, codatatypes_ok) =
   683           reconstruct_hol_model
   684               {show_datatypes = show_datatypes, show_skolems = show_skolems,
   685                show_consts = show_consts}
   686               scope formats atomss real_frees pseudo_frees free_names sel_names
   687               nonsel_names rel_table bounds
   688         val genuine_means_genuine =
   689           got_all_user_axioms andalso none_true wfs andalso
   690           sound_finitizes andalso total_consts <> SOME true andalso
   691           codatatypes_ok
   692         fun assms_prop () =
   693           Logic.mk_conjunction_list (neg_t :: def_assm_ts @ nondef_assm_ts)
   694       in
   695         (pprint_a (Pretty.chunks
   696              [Pretty.blk (0,
   697                   (pstrs ((if mode = Auto_Try then "Auto " else "") ^
   698                           "Nitpick found a" ^
   699                           (if not genuine then " potentially spurious "
   700                            else if genuine_means_genuine then " "
   701                            else " quasi genuine ") ^ das_wort_model) @
   702                    (case pretties_for_scope scope verbose of
   703                       [] => []
   704                     | pretties => pstrs " for " @ pretties) @
   705                    [Pretty.str ":\n"])),
   706               Pretty.indent indent_size reconstructed_model]);
   707          print_t (K "% SZS output end FiniteModel");
   708          if genuine then
   709            (if check_genuine andalso standard then
   710               case prove_hol_model scope tac_timeout free_names sel_names
   711                                    rel_table bounds (assms_prop ()) of
   712                 SOME true =>
   713                 print ("Confirmation by \"auto\": The above " ^
   714                        das_wort_model ^ " is really genuine.")
   715               | SOME false =>
   716                 if genuine_means_genuine then
   717                   error ("A supposedly genuine " ^ das_wort_model ^ " was \
   718                          \shown to be spurious by \"auto\".\nThis should never \
   719                          \happen.\nPlease send a bug report to blanchet\
   720                          \te@in.tum.de.")
   721                  else
   722                    print ("Refutation by \"auto\": The above " ^
   723                           das_wort_model ^ " is spurious.")
   724                | NONE => print "No confirmation by \"auto\"."
   725             else
   726               ();
   727             if not standard andalso likely_in_struct_induct_step then
   728               print "The existence of a nonstandard model suggests that the \
   729                     \induction hypothesis is not general enough or may even be \
   730                     \wrong. See the Nitpick manual's \"Inductive Properties\" \
   731                     \section for details (\"isabelle doc nitpick\")."
   732             else
   733               ();
   734             if has_lonely_bool_var orig_t then
   735               print "Hint: Maybe you forgot a colon after the lemma's name?"
   736             else if has_syntactic_sorts orig_t then
   737               print "Hint: Maybe you forgot a type constraint?"
   738             else
   739               ();
   740             if not genuine_means_genuine then
   741               if no_poly_user_axioms then
   742                 let
   743                   val options =
   744                     [] |> not got_all_mono_user_axioms
   745                           ? cons ("user_axioms", "\"true\"")
   746                        |> not (none_true wfs)
   747                           ? cons ("wf", "\"smart\" or \"false\"")
   748                        |> not sound_finitizes
   749                           ? cons ("finitize", "\"smart\" or \"false\"")
   750                        |> total_consts = SOME true
   751                           ? cons ("total_consts", "\"smart\" or \"false\"")
   752                        |> not codatatypes_ok
   753                           ? cons ("bisim_depth", "a nonnegative value")
   754                   val ss =
   755                     map (fn (name, value) => quote name ^ " set to " ^ value)
   756                         options
   757                 in
   758                   print ("Try again with " ^
   759                          space_implode " " (serial_commas "and" ss) ^
   760                          " to confirm that the " ^ das_wort_model ^
   761                          " is genuine.")
   762                 end
   763               else
   764                 print ("Nitpick is unable to guarantee the authenticity of \
   765                        \the " ^ das_wort_model ^ " in the presence of \
   766                        \polymorphic axioms.")
   767             else
   768               ();
   769             NONE)
   770          else
   771            if not genuine then
   772              (Unsynchronized.inc met_potential;
   773               if check_potential then
   774                 let
   775                   val status = prove_hol_model scope tac_timeout free_names
   776                                                sel_names rel_table bounds
   777                                                (assms_prop ())
   778                 in
   779                   (case status of
   780                      SOME true => print ("Confirmation by \"auto\": The \
   781                                          \above " ^ das_wort_model ^
   782                                          " is genuine.")
   783                    | SOME false => print ("Refutation by \"auto\": The above " ^
   784                                           das_wort_model ^ " is spurious.")
   785                    | NONE => print "No confirmation by \"auto\".");
   786                   status
   787                 end
   788               else
   789                 NONE)
   790            else
   791              NONE)
   792         |> pair genuine_means_genuine
   793       end
   794     fun solve_any_problem (found_really_genuine, max_potential, max_genuine,
   795                            donno) first_time problems =
   796       let
   797         val max_potential = Int.max (0, max_potential)
   798         val max_genuine = Int.max (0, max_genuine)
   799         fun print_and_check genuine (j, bounds) =
   800           print_and_check_model genuine bounds (snd (nth problems j))
   801         val max_solutions = max_potential + max_genuine
   802                             |> not incremental ? Integer.min 1
   803       in
   804         if max_solutions <= 0 then
   805           (found_really_genuine, 0, 0, donno)
   806         else
   807           case KK.solve_any_problem debug overlord deadline max_threads
   808                                     max_solutions (map fst problems) of
   809             KK.JavaNotFound =>
   810             (print_nt java_not_found_message;
   811              (found_really_genuine, max_potential, max_genuine, donno + 1))
   812           | KK.JavaTooOld =>
   813             (print_nt java_too_old_message;
   814              (found_really_genuine, max_potential, max_genuine, donno + 1))
   815           | KK.KodkodiNotInstalled =>
   816             (print_nt kodkodi_not_installed_message;
   817              (found_really_genuine, max_potential, max_genuine, donno + 1))
   818           | KK.Normal ([], unsat_js, s) =>
   819             (update_checked_problems problems unsat_js; show_kodkod_warning s;
   820              (found_really_genuine, max_potential, max_genuine, donno))
   821           | KK.Normal (sat_ps, unsat_js, s) =>
   822             let
   823               val (lib_ps, con_ps) =
   824                 List.partition (#unsound o snd o nth problems o fst) sat_ps
   825             in
   826               update_checked_problems problems (unsat_js @ map fst lib_ps);
   827               show_kodkod_warning s;
   828               if null con_ps then
   829                 let
   830                   val genuine_codes =
   831                     lib_ps |> take max_potential
   832                            |> map (print_and_check false)
   833                            |> filter (curry (op =) (SOME true) o snd)
   834                   val found_really_genuine =
   835                     found_really_genuine orelse exists fst genuine_codes
   836                   val num_genuine = length genuine_codes
   837                   val max_genuine = max_genuine - num_genuine
   838                   val max_potential = max_potential
   839                                       - (length lib_ps - num_genuine)
   840                 in
   841                   if max_genuine <= 0 then
   842                     (found_really_genuine, 0, 0, donno)
   843                   else
   844                     let
   845                       (* "co_js" is the list of sound problems whose unsound
   846                          pendants couldn't be satisfied and hence that most
   847                          probably can't be satisfied themselves. *)
   848                       val co_js =
   849                         map (fn j => j - 1) unsat_js
   850                         |> filter (fn j =>
   851                                       j >= 0 andalso
   852                                       scopes_equivalent
   853                                           (#scope (snd (nth problems j)),
   854                                            #scope (snd (nth problems (j + 1)))))
   855                       val bye_js = sort_distinct int_ord (map fst sat_ps @
   856                                                           unsat_js @ co_js)
   857                       val problems =
   858                         problems |> filter_out_indices bye_js
   859                                  |> max_potential <= 0
   860                                     ? filter_out (#unsound o snd)
   861                     in
   862                       solve_any_problem (found_really_genuine, max_potential,
   863                                          max_genuine, donno) false problems
   864                     end
   865                 end
   866               else
   867                 let
   868                   val genuine_codes =
   869                     con_ps |> take max_genuine
   870                            |> map (print_and_check true)
   871                   val max_genuine = max_genuine - length genuine_codes
   872                   val found_really_genuine =
   873                     found_really_genuine orelse exists fst genuine_codes
   874                 in
   875                   if max_genuine <= 0 orelse not first_time then
   876                     (found_really_genuine, 0, max_genuine, donno)
   877                   else
   878                     let
   879                       val bye_js = sort_distinct int_ord
   880                                                  (map fst sat_ps @ unsat_js)
   881                       val problems =
   882                         problems |> filter_out_indices bye_js
   883                                  |> filter_out (#unsound o snd)
   884                     in
   885                       solve_any_problem (found_really_genuine, 0, max_genuine,
   886                                          donno) false problems
   887                     end
   888                 end
   889             end
   890           | KK.TimedOut unsat_js =>
   891             (update_checked_problems problems unsat_js; raise TimeLimit.TimeOut)
   892           | KK.Error (s, unsat_js) =>
   893             (update_checked_problems problems unsat_js;
   894              print_v (K ("Kodkod error: " ^ s ^ "."));
   895              (found_really_genuine, max_potential, max_genuine, donno + 1))
   896       end
   897 
   898     fun run_batch j n scopes (found_really_genuine, max_potential, max_genuine,
   899                               donno) =
   900       let
   901         val _ =
   902           if null scopes then
   903             print_nt (K "The scope specification is inconsistent.")
   904           else if verbose then
   905             pprint_nt (fn () => Pretty.chunks
   906                 [Pretty.blk (0,
   907                      pstrs ((if n > 1 then
   908                                "Batch " ^ string_of_int (j + 1) ^ " of " ^
   909                                signed_string_of_int n ^ ": "
   910                              else
   911                                "") ^
   912                             "Trying " ^ string_of_int (length scopes) ^
   913                             " scope" ^ plural_s_for_list scopes ^ ":")),
   914                  Pretty.indent indent_size
   915                      (Pretty.chunks (map2
   916                           (fn j => fn scope =>
   917                               Pretty.block (
   918                                   (case pretties_for_scope scope true of
   919                                      [] => [Pretty.str "Empty"]
   920                                    | pretties => pretties) @
   921                                   [Pretty.str (if j = 1 then "." else ";")]))
   922                           (length scopes downto 1) scopes))])
   923           else
   924             ()
   925         fun add_problem_for_scope (scope, unsound) (problems, donno) =
   926           (check_deadline ();
   927            case problem_for_scope unsound scope of
   928              SOME problem =>
   929              (problems
   930               |> (null problems orelse
   931                   not (KK.problems_equivalent (fst problem, fst (hd problems))))
   932                   ? cons problem, donno)
   933            | NONE => (problems, donno + 1))
   934         val (problems, donno) =
   935           fold add_problem_for_scope
   936                (map_product pair scopes
   937                     ((if max_genuine > 0 then [false] else []) @
   938                      (if max_potential > 0 then [true] else [])))
   939                ([], donno)
   940         val _ = Unsynchronized.change generated_problems (append problems)
   941         val _ = Unsynchronized.change generated_scopes (append scopes)
   942         val _ =
   943           if j + 1 = n then
   944             let
   945               val (unsound_problems, sound_problems) =
   946                 List.partition (#unsound o snd) (!generated_problems)
   947             in
   948               if not (null sound_problems) andalso
   949                  forall (KK.is_problem_trivially_false o fst)
   950                         sound_problems then
   951                 print_nt (fn () =>
   952                     "Warning: The conjecture " ^
   953                     (if falsify then "either trivially holds"
   954                      else "is either trivially unsatisfiable") ^
   955                     " for the given scopes or lies outside Nitpick's supported \
   956                     \fragment." ^
   957                     (if exists (not o KK.is_problem_trivially_false o fst)
   958                                unsound_problems then
   959                        " Only potentially spurious " ^ das_wort_model ^
   960                        "s may be found."
   961                      else
   962                        ""))
   963               else
   964                 ()
   965             end
   966           else
   967             ()
   968       in
   969         solve_any_problem (found_really_genuine, max_potential, max_genuine,
   970                            donno) true (rev problems)
   971       end
   972 
   973     fun scope_count (problems : rich_problem list) scope =
   974       length (filter (curry scopes_equivalent scope o #scope o snd) problems)
   975     fun excipit did_so_and_so =
   976       let
   977         val do_filter =
   978           if !met_potential = max_potential then filter_out (#unsound o snd)
   979           else I
   980         val total = length (!scopes)
   981         val unsat =
   982           fold (fn scope =>
   983                    case scope_count (do_filter (!generated_problems)) scope of
   984                      0 => I
   985                    | n =>
   986                      scope_count (do_filter (these (!checked_problems)))
   987                                  scope = n
   988                      ? Integer.add 1) (!generated_scopes) 0
   989       in
   990         (if mode = TPTP then "% SZS status Unknown\n" else "") ^
   991         "Nitpick " ^ did_so_and_so ^
   992         (if is_some (!checked_problems) andalso total > 0 then
   993            " " ^ string_of_int unsat ^ " of " ^ string_of_int total ^ " scope"
   994            ^ plural_s total
   995          else
   996            "") ^ "."
   997       end
   998 
   999     val (skipped, the_scopes) =
  1000       all_scopes hol_ctxt binarize cards_assigns maxes_assigns iters_assigns
  1001                  bitss bisim_depths mono_Ts nonmono_Ts deep_dataTs
  1002                  finitizable_dataTs
  1003     val _ = if skipped > 0 then
  1004               print_nt (fn () => "Too many scopes. Skipping " ^
  1005                                  string_of_int skipped ^ " scope" ^
  1006                                  plural_s skipped ^
  1007                                  ". (Consider using \"mono\" or \
  1008                                  \\"merge_type_vars\" to prevent this.)")
  1009             else
  1010               ()
  1011     val _ = scopes := the_scopes
  1012 
  1013     fun run_batches _ _ []
  1014                     (found_really_genuine, max_potential, max_genuine, donno) =
  1015         if donno > 0 andalso max_genuine > 0 then
  1016           (print_nt (fn () => excipit "checked"); unknownN)
  1017         else if max_genuine = original_max_genuine then
  1018           if max_potential = original_max_potential then
  1019             (print_t (K "% SZS status Unknown");
  1020              print_nt (fn () =>
  1021                  "Nitpick found no " ^ das_wort_model ^ "." ^
  1022                  (if not standard andalso likely_in_struct_induct_step then
  1023                     " This suggests that the induction hypothesis might be \
  1024                     \general enough to prove this subgoal."
  1025                   else
  1026                     "")); if skipped > 0 then unknownN else noneN)
  1027           else
  1028             (print_nt (fn () =>
  1029                  excipit ("could not find a" ^
  1030                           (if max_genuine = 1 then
  1031                              " better " ^ das_wort_model ^ "."
  1032                            else
  1033                              "ny better " ^ das_wort_model ^ "s.") ^
  1034                           " It checked"));
  1035              potentialN)
  1036         else if found_really_genuine then
  1037           genuineN
  1038         else
  1039           quasi_genuineN
  1040       | run_batches j n (batch :: batches) z =
  1041         let val (z as (_, _, max_genuine, _)) = run_batch j n batch z in
  1042           run_batches (j + 1) n (if max_genuine > 0 then batches else []) z
  1043         end
  1044 
  1045     val batches = chunk_list batch_size (!scopes)
  1046     val outcome_code =
  1047       run_batches 0 (length batches) batches
  1048                   (false, max_potential, max_genuine, 0)
  1049       handle TimeLimit.TimeOut =>
  1050              (print_nt (fn () => excipit "ran out of time after checking");
  1051               if !met_potential > 0 then potentialN else unknownN)
  1052     val _ = print_v (fn () =>
  1053                 "Total time: " ^ string_from_time (Timer.checkRealTimer timer) ^
  1054                 ".")
  1055   in (outcome_code, !state_ref) end
  1056 
  1057 (* Give the inner timeout a chance. *)
  1058 val timeout_bonus = seconds 1.0
  1059 
  1060 fun pick_nits_in_term state (params as {debug, timeout, expect, ...}) mode i n
  1061                       step subst def_assm_ts nondef_assm_ts orig_t =
  1062   let
  1063     val print_nt = if is_mode_nt mode then Output.urgent_message else K ()
  1064     val print_t = if mode = TPTP then Output.urgent_message else K ()
  1065   in
  1066     if getenv "KODKODI" = "" then
  1067       (* The "expect" argument is deliberately ignored if Kodkodi is missing so
  1068          that the "Nitpick_Examples" can be processed on any machine. *)
  1069       (print_nt (Pretty.string_of (plazy kodkodi_not_installed_message));
  1070        ("no_kodkodi", state))
  1071     else
  1072       let
  1073         val unknown_outcome = (unknownN, state)
  1074         val deadline = Option.map (curry Time.+ (Time.now ())) timeout
  1075         val outcome as (outcome_code, _) =
  1076           time_limit (if debug orelse is_none timeout then NONE
  1077                       else SOME (Time.+ (the timeout, timeout_bonus)))
  1078               (pick_them_nits_in_term deadline state params mode i n step subst
  1079                                       def_assm_ts nondef_assm_ts) orig_t
  1080           handle TOO_LARGE (_, details) =>
  1081                  (print_t "% SZS status Unknown";
  1082                   print_nt ("Limit reached: " ^ details ^ "."); unknown_outcome)
  1083                | TOO_SMALL (_, details) =>
  1084                  (print_t "% SZS status Unknown";
  1085                   print_nt ("Limit reached: " ^ details ^ "."); unknown_outcome)
  1086                | Kodkod.SYNTAX (_, details) =>
  1087                  (print_t "% SZS status Unknown";
  1088                   print_nt ("Malformed Kodkodi output: " ^ details ^ ".");
  1089                   unknown_outcome)
  1090                | TimeLimit.TimeOut =>
  1091                  (print_t "% SZS status TimedOut";
  1092                   print_nt "Nitpick ran out of time."; unknown_outcome)
  1093       in
  1094         if expect = "" orelse outcome_code = expect then outcome
  1095         else error ("Unexpected outcome: " ^ quote outcome_code ^ ".")
  1096       end
  1097   end
  1098 
  1099 fun is_fixed_equation ctxt
  1100                       (Const (@{const_name "=="}, _) $ Free (s, _) $ Const _) =
  1101     Variable.is_fixed ctxt s
  1102   | is_fixed_equation _ _ = false
  1103 fun extract_fixed_frees ctxt (assms, t) =
  1104   let
  1105     val (subst, other_assms) =
  1106       List.partition (is_fixed_equation ctxt) assms
  1107       |>> map Logic.dest_equals
  1108   in (subst, other_assms, subst_atomic subst t) end
  1109 
  1110 fun pick_nits_in_subgoal state params mode i step =
  1111   let
  1112     val ctxt = Proof.context_of state
  1113     val t = state |> Proof.raw_goal |> #goal |> prop_of
  1114   in
  1115     case Logic.count_prems t of
  1116       0 => (Output.urgent_message "No subgoal!"; (noneN, state))
  1117     | n =>
  1118       let
  1119         val t = Logic.goal_params t i |> fst
  1120         val assms = map term_of (Assumption.all_assms_of ctxt)
  1121         val (subst, assms, t) = extract_fixed_frees ctxt (assms, t)
  1122       in pick_nits_in_term state params mode i n step subst [] assms t end
  1123   end
  1124 
  1125 end;