src/HOL/Tools/Nitpick/nitpick.ML
author blanchet
Thu Dec 19 13:43:21 2013 +0100 (2013-12-19 ago)
changeset 54816 10d48c2a3e32
parent 53815 e8aa538e959e
child 55539 0819931d652d
permissions -rw-r--r--
made timeouts in Sledgehammer not be 'option's -- simplified lots of code
     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      spy: bool,
    33      user_axioms: bool option,
    34      assms: bool,
    35      whacks: term list,
    36      merge_type_vars: bool,
    37      binary_ints: bool option,
    38      destroy_constrs: bool,
    39      specialize: bool,
    40      star_linear_preds: bool,
    41      total_consts: bool option,
    42      needs: term list option,
    43      peephole_optim: bool,
    44      datatype_sym_break: int,
    45      kodkod_sym_break: int,
    46      timeout: Time.time,
    47      tac_timeout: Time.time,
    48      max_threads: int,
    49      show_datatypes: bool,
    50      show_skolems: bool,
    51      show_consts: bool,
    52      evals: term list,
    53      formats: (term option * int list) list,
    54      atomss: (typ option * string list) list,
    55      max_potential: int,
    56      max_genuine: int,
    57      check_potential: bool,
    58      check_genuine: bool,
    59      batch_size: int,
    60      expect: string}
    61 
    62   val genuineN : string
    63   val quasi_genuineN : string
    64   val potentialN : string
    65   val noneN : string
    66   val unknownN : string
    67   val register_frac_type : string -> (string * string) list -> theory -> theory
    68   val unregister_frac_type : string -> theory -> theory
    69   val register_codatatype : typ -> string -> styp list -> theory -> theory
    70   val unregister_codatatype : typ -> theory -> theory
    71   val register_term_postprocessor :
    72     typ -> term_postprocessor -> theory -> theory
    73   val unregister_term_postprocessor : typ -> theory -> theory
    74   val pick_nits_in_term :
    75     Proof.state -> params -> mode -> int -> int -> int -> (term * term) list
    76     -> term list -> term list -> term -> string * Proof.state
    77   val pick_nits_in_subgoal :
    78     Proof.state -> params -> mode -> int -> int -> string * Proof.state
    79 end;
    80 
    81 structure Nitpick : NITPICK =
    82 struct
    83 
    84 open Nitpick_Util
    85 open Nitpick_HOL
    86 open Nitpick_Preproc
    87 open Nitpick_Mono
    88 open Nitpick_Scope
    89 open Nitpick_Peephole
    90 open Nitpick_Rep
    91 open Nitpick_Nut
    92 open Nitpick_Kodkod
    93 open Nitpick_Model
    94 
    95 structure KK = Kodkod
    96 
    97 datatype mode = Auto_Try | Try | Normal | TPTP
    98 
    99 fun is_mode_nt mode = (mode = Normal orelse mode = TPTP)
   100 
   101 type params =
   102   {cards_assigns: (typ option * int list) list,
   103    maxes_assigns: (styp option * int list) list,
   104    iters_assigns: (styp option * int list) list,
   105    bitss: int list,
   106    bisim_depths: int list,
   107    boxes: (typ option * bool option) list,
   108    finitizes: (typ option * bool option) list,
   109    monos: (typ option * bool option) list,
   110    stds: (typ option * bool) list,
   111    wfs: (styp option * bool option) list,
   112    sat_solver: string,
   113    blocking: bool,
   114    falsify: bool,
   115    debug: bool,
   116    verbose: bool,
   117    overlord: bool,
   118    spy: bool,
   119    user_axioms: bool option,
   120    assms: bool,
   121    whacks: term list,
   122    merge_type_vars: bool,
   123    binary_ints: bool option,
   124    destroy_constrs: bool,
   125    specialize: bool,
   126    star_linear_preds: bool,
   127    total_consts: bool option,
   128    needs: term list option,
   129    peephole_optim: bool,
   130    datatype_sym_break: int,
   131    kodkod_sym_break: int,
   132    timeout: Time.time,
   133    tac_timeout: Time.time,
   134    max_threads: int,
   135    show_datatypes: bool,
   136    show_skolems: bool,
   137    show_consts: bool,
   138    evals: term list,
   139    formats: (term option * int list) list,
   140    atomss: (typ option * string list) list,
   141    max_potential: int,
   142    max_genuine: int,
   143    check_potential: bool,
   144    check_genuine: bool,
   145    batch_size: int,
   146    expect: string}
   147 
   148 val genuineN = "genuine"
   149 val quasi_genuineN = "quasi_genuine"
   150 val potentialN = "potential"
   151 val noneN = "none"
   152 val unknownN = "unknown"
   153 
   154 (* TODO: eliminate these historical aliases *)
   155 val register_frac_type = Nitpick_HOL.register_frac_type_global
   156 val unregister_frac_type = Nitpick_HOL.unregister_frac_type_global
   157 val register_codatatype = Nitpick_HOL.register_codatatype_global
   158 val unregister_codatatype = Nitpick_HOL.unregister_codatatype_global
   159 val register_term_postprocessor =
   160   Nitpick_Model.register_term_postprocessor_global
   161 val unregister_term_postprocessor =
   162   Nitpick_Model.unregister_term_postprocessor_global
   163 
   164 type problem_extension =
   165   {free_names: nut list,
   166    sel_names: nut list,
   167    nonsel_names: nut list,
   168    rel_table: nut NameTable.table,
   169    unsound: bool,
   170    scope: scope}
   171 
   172 type rich_problem = KK.problem * problem_extension
   173 
   174 fun pretties_for_formulas _ _ [] = []
   175   | pretties_for_formulas ctxt s ts =
   176     [Pretty.str (s ^ plural_s_for_list ts ^ ":"),
   177      Pretty.indent indent_size (Pretty.chunks
   178          (map2 (fn j => fn t =>
   179                    Pretty.block [t |> shorten_names_in_term
   180                                    |> Syntax.pretty_term ctxt,
   181                                  Pretty.str (if j = 1 then "." else ";")])
   182                (length ts downto 1) ts))]
   183 
   184 val isabelle_wrong_message =
   185   "Something appears to be wrong with your Isabelle installation."
   186 fun java_not_found_message () =
   187   "Java could not be launched. " ^ isabelle_wrong_message
   188 fun java_too_old_message () =
   189   "The Java version is too old. " ^ isabelle_wrong_message
   190 fun kodkodi_not_installed_message () =
   191   "Nitpick requires the external Java program Kodkodi."
   192 fun kodkodi_too_old_message () = "The installed Kodkodi version is too old."
   193 val max_unsound_delay_ms = 200
   194 val max_unsound_delay_percent = 2
   195 
   196 fun unsound_delay_for_timeout timeout =
   197   Int.max (0, Int.min (max_unsound_delay_ms,
   198                        Time.toMilliseconds timeout
   199                        * max_unsound_delay_percent div 100))
   200 
   201 fun none_true assigns = forall (not_equal (SOME true) o snd) assigns
   202 
   203 fun has_lonely_bool_var (@{const Pure.conjunction}
   204                          $ (@{const Trueprop} $ Free _) $ _) = true
   205   | has_lonely_bool_var _ = false
   206 
   207 val syntactic_sorts =
   208   @{sort "{default,zero,one,plus,minus,uminus,times,inverse,abs,sgn,ord,equal}"} @
   209   @{sort numeral}
   210 fun has_tfree_syntactic_sort (TFree (_, S as _ :: _)) =
   211     subset (op =) (S, syntactic_sorts)
   212   | has_tfree_syntactic_sort _ = false
   213 val has_syntactic_sorts = exists_type (exists_subtype has_tfree_syntactic_sort)
   214 
   215 fun plazy f = Pretty.blk (0, pstrs (f ()))
   216 
   217 fun pick_them_nits_in_term deadline state (params : params) mode i n step
   218                            subst def_assm_ts nondef_assm_ts orig_t =
   219   let
   220     val timer = Timer.startRealTimer ()
   221     val thy = Proof.theory_of state
   222     val ctxt = Proof.context_of state
   223 (* FIXME: reintroduce code before new release:
   224 
   225     val nitpick_thy = Thy_Info.get_theory "Nitpick"
   226     val _ = Theory.subthy (nitpick_thy, thy) orelse
   227             error "You must import the theory \"Nitpick\" to use Nitpick"
   228 *)
   229     val {cards_assigns, maxes_assigns, iters_assigns, bitss, bisim_depths,
   230          boxes, finitizes, monos, stds, wfs, sat_solver, falsify, debug,
   231          verbose, overlord, spy, user_axioms, assms, whacks, merge_type_vars,
   232          binary_ints, destroy_constrs, specialize, star_linear_preds,
   233          total_consts, needs, peephole_optim, datatype_sym_break,
   234          kodkod_sym_break, tac_timeout, max_threads, show_datatypes,
   235          show_skolems, show_consts, evals, formats, atomss, max_potential,
   236          max_genuine, check_potential, check_genuine, batch_size, ...} = params
   237     val state_ref = Unsynchronized.ref state
   238     fun pprint print =
   239       if mode = Auto_Try then
   240         Unsynchronized.change state_ref o Proof.goal_message o K
   241         o Pretty.mark Markup.information
   242       else
   243         print o Pretty.string_of
   244     val pprint_a = pprint Output.urgent_message
   245     fun pprint_nt f = () |> is_mode_nt mode ? pprint Output.urgent_message o f
   246     fun pprint_v f = () |> verbose ? pprint Output.urgent_message o f
   247     fun pprint_d f = () |> debug ? pprint tracing o f
   248     val print = pprint Output.urgent_message o curry Pretty.blk 0 o pstrs
   249     fun print_t f = () |> mode = TPTP ? print o f
   250 (*
   251     val print_g = pprint tracing o Pretty.str
   252 *)
   253     val print_nt = pprint_nt o K o plazy
   254     val print_v = pprint_v o K o plazy
   255 
   256     fun check_deadline () =
   257       if Time.compare (Time.now (), deadline) <> LESS then
   258         raise TimeLimit.TimeOut
   259       else
   260         ()
   261 
   262     val (def_assm_ts, nondef_assm_ts) =
   263       if assms orelse mode <> Normal then (def_assm_ts, nondef_assm_ts)
   264       else ([], [])
   265     val _ =
   266       if step = 0 then
   267         print_nt (fn () => "Nitpicking formula...")
   268       else
   269         pprint_nt (fn () => Pretty.chunks (
   270             pretties_for_formulas ctxt ("Nitpicking " ^
   271                 (if i <> 1 orelse n <> 1 then
   272                    "subgoal " ^ string_of_int i ^ " of " ^ string_of_int n
   273                  else
   274                    "goal")) [Logic.list_implies (nondef_assm_ts, orig_t)]))
   275     val _ = spying spy (fn () => (state, i, "starting " ^ @{make_string} mode ^ " mode"))
   276     val _ = print_v (enclose "Timestamp: " "." o Date.fmt "%H:%M:%S"
   277                      o Date.fromTimeLocal o Time.now)
   278     val neg_t = if falsify then Logic.mk_implies (orig_t, @{prop False})
   279                 else orig_t
   280     val conj_ts = neg_t :: def_assm_ts @ nondef_assm_ts @ evals @ these needs
   281     val tfree_table =
   282       if merge_type_vars then merged_type_var_table_for_terms thy conj_ts
   283       else []
   284     val merge_tfrees = merge_type_vars_in_term thy merge_type_vars tfree_table
   285     val neg_t = neg_t |> merge_tfrees
   286     val def_assm_ts = def_assm_ts |> map merge_tfrees
   287     val nondef_assm_ts = nondef_assm_ts |> map merge_tfrees
   288     val evals = evals |> map merge_tfrees
   289     val needs = needs |> Option.map (map merge_tfrees)
   290     val conj_ts = neg_t :: def_assm_ts @ nondef_assm_ts @ evals @ these needs
   291     val original_max_potential = max_potential
   292     val original_max_genuine = max_genuine
   293     val max_bisim_depth = fold Integer.max bisim_depths ~1
   294     val case_names = case_const_names ctxt stds
   295     val defs = def_assm_ts @ all_defs_of thy subst
   296     val nondefs = all_nondefs_of ctxt subst
   297     val def_tables = const_def_tables ctxt subst defs
   298     val nondef_table = const_nondef_table nondefs
   299     val simp_table = Unsynchronized.ref (const_simp_table ctxt subst)
   300     val psimp_table = const_psimp_table ctxt subst
   301     val choice_spec_table = const_choice_spec_table ctxt subst
   302     val nondefs =
   303       nondefs |> filter_out (is_choice_spec_axiom thy choice_spec_table)
   304     val intro_table = inductive_intro_table ctxt subst def_tables
   305     val ground_thm_table = ground_theorem_table thy
   306     val ersatz_table = ersatz_table ctxt
   307     val hol_ctxt as {wf_cache, ...} =
   308       {thy = thy, ctxt = ctxt, max_bisim_depth = max_bisim_depth, boxes = boxes,
   309        stds = stds, wfs = wfs, user_axioms = user_axioms, debug = debug,
   310        whacks = whacks, binary_ints = binary_ints,
   311        destroy_constrs = destroy_constrs, specialize = specialize,
   312        star_linear_preds = star_linear_preds, total_consts = total_consts,
   313        needs = needs, tac_timeout = tac_timeout, evals = evals,
   314        case_names = case_names, def_tables = def_tables,
   315        nondef_table = nondef_table, nondefs = nondefs, simp_table = simp_table,
   316        psimp_table = psimp_table, choice_spec_table = choice_spec_table,
   317        intro_table = intro_table, ground_thm_table = ground_thm_table,
   318        ersatz_table = ersatz_table, skolems = Unsynchronized.ref [],
   319        special_funs = Unsynchronized.ref [],
   320        unrolled_preds = Unsynchronized.ref [], wf_cache = Unsynchronized.ref [],
   321        constr_cache = Unsynchronized.ref []}
   322     val pseudo_frees = []
   323     val real_frees = fold Term.add_frees conj_ts []
   324     val _ = null (fold Term.add_tvars conj_ts []) orelse
   325             error "Nitpick cannot handle goals with schematic type variables."
   326     val (nondef_ts, def_ts, need_ts, got_all_mono_user_axioms,
   327          no_poly_user_axioms, binarize) =
   328       preprocess_formulas hol_ctxt nondef_assm_ts neg_t
   329     val got_all_user_axioms =
   330       got_all_mono_user_axioms andalso no_poly_user_axioms
   331 
   332     fun print_wf (x, (gfp, wf)) =
   333       pprint_nt (fn () => Pretty.blk (0,
   334           pstrs ("The " ^ (if gfp then "co" else "") ^ "inductive predicate \"")
   335           @ Syntax.pretty_term ctxt (Const x) ::
   336           pstrs (if wf then
   337                    "\" was proved well-founded. Nitpick can compute it \
   338                    \efficiently."
   339                  else
   340                    "\" could not be proved well-founded. Nitpick might need to \
   341                    \unroll it.")))
   342     val _ = if verbose then List.app print_wf (!wf_cache) else ()
   343     val das_wort_formula = if falsify then "Negated conjecture" else "Formula"
   344     val _ =
   345       pprint_d (fn () => Pretty.chunks
   346           (pretties_for_formulas ctxt das_wort_formula [hd nondef_ts] @
   347            pretties_for_formulas ctxt "Relevant definitional axiom" def_ts @
   348            pretties_for_formulas ctxt "Relevant nondefinitional axiom"
   349                                  (tl nondef_ts)))
   350     val _ = List.app (ignore o Term.type_of) (nondef_ts @ def_ts)
   351             handle TYPE (_, Ts, ts) =>
   352                    raise TYPE ("Nitpick.pick_them_nits_in_term", Ts, ts)
   353 
   354     val nondef_us = nondef_ts |> map (nut_from_term hol_ctxt Eq)
   355     val def_us = def_ts |> map (nut_from_term hol_ctxt DefEq)
   356     val need_us = need_ts |> map (nut_from_term hol_ctxt Eq)
   357     val (free_names, const_names) =
   358       fold add_free_and_const_names (nondef_us @ def_us @ need_us) ([], [])
   359     val (sel_names, nonsel_names) =
   360       List.partition (is_sel o nickname_of) const_names
   361     val sound_finitizes = none_true finitizes
   362     val standard = forall snd stds
   363 (*
   364     val _ =
   365       List.app (print_g o string_for_nut ctxt) (nondef_us @ def_us @ need_us)
   366 *)
   367 
   368     val unique_scope = forall (curry (op =) 1 o length o snd) cards_assigns
   369     fun monotonicity_message Ts extra =
   370       let val pretties = map (pretty_maybe_quote o pretty_for_type ctxt) Ts in
   371         Pretty.blk (0,
   372           pstrs ("The type" ^ plural_s_for_list pretties ^ " ") @
   373           pretty_serial_commas "and" pretties @
   374           pstrs (" " ^
   375                  (if none_true monos then
   376                     "passed the monotonicity test"
   377                   else
   378                     (if length pretties = 1 then "is" else "are") ^
   379                     " considered monotonic") ^
   380                  ". " ^ extra))
   381       end
   382     fun is_type_fundamentally_monotonic T =
   383       (is_datatype ctxt stds T andalso not (is_quot_type ctxt T) andalso
   384        (not (is_pure_typedef ctxt T) orelse is_univ_typedef ctxt T)) orelse
   385       is_number_type ctxt T orelse is_bit_type T
   386     fun is_type_actually_monotonic T =
   387       TimeLimit.timeLimit tac_timeout (formulas_monotonic hol_ctxt binarize T)
   388                           (nondef_ts, def_ts)
   389       handle TimeLimit.TimeOut => false
   390     fun is_type_kind_of_monotonic T =
   391       case triple_lookup (type_match thy) monos T of
   392         SOME (SOME false) => false
   393       | _ => is_type_actually_monotonic T
   394     fun is_type_monotonic T =
   395       unique_scope orelse
   396       case triple_lookup (type_match thy) monos T of
   397         SOME (SOME b) => b
   398       | _ => is_type_fundamentally_monotonic T orelse
   399              is_type_actually_monotonic T
   400     fun is_deep_datatype_finitizable T =
   401       triple_lookup (type_match thy) finitizes T = SOME (SOME true)
   402     fun is_shallow_datatype_finitizable (T as Type (@{type_name fun_box}, _)) =
   403         is_type_kind_of_monotonic T
   404       | is_shallow_datatype_finitizable T =
   405         case triple_lookup (type_match thy) finitizes T of
   406           SOME (SOME b) => b
   407         | _ => is_type_kind_of_monotonic T
   408     fun is_datatype_deep T =
   409       not standard orelse T = @{typ unit} orelse T = nat_T orelse
   410       is_word_type T orelse
   411       exists (curry (op =) T o domain_type o type_of) sel_names
   412     val all_Ts = ground_types_in_terms hol_ctxt binarize (nondef_ts @ def_ts)
   413                  |> sort Term_Ord.typ_ord
   414     val _ =
   415       if verbose andalso binary_ints = SOME true andalso
   416          exists (member (op =) [nat_T, int_T]) all_Ts then
   417         print_v (K "The option \"binary_ints\" will be ignored because of the \
   418                    \presence of rationals, reals, \"Suc\", \"gcd\", or \"lcm\" \
   419                    \in the problem or because of the \"non_std\" option.")
   420       else
   421         ()
   422     val _ =
   423       if mode = Normal andalso
   424          exists (fn Type (@{type_name Datatype.node}, _) => true | _ => false)
   425                 all_Ts then
   426         print_nt (K ("Warning: The problem involves directly or indirectly the \
   427                      \internal type " ^ quote @{type_name Datatype.node} ^
   428                      ". This type is very Nitpick-unfriendly, and its presence \
   429                      \usually indicates either a failure of abstraction or a \
   430                      \quirk in Nitpick."))
   431       else
   432         ()
   433     val (mono_Ts, nonmono_Ts) = List.partition is_type_monotonic all_Ts
   434     val _ =
   435       if verbose andalso not unique_scope then
   436         case filter_out is_type_fundamentally_monotonic mono_Ts of
   437           [] => ()
   438         | interesting_mono_Ts =>
   439           pprint_v (K (monotonicity_message interesting_mono_Ts
   440                           "Nitpick might be able to skip some scopes."))
   441       else
   442         ()
   443     val (deep_dataTs, shallow_dataTs) =
   444       all_Ts |> filter (is_datatype ctxt stds)
   445              |> List.partition is_datatype_deep
   446     val finitizable_dataTs =
   447       (deep_dataTs |> filter_out (is_finite_type hol_ctxt)
   448                    |> filter is_deep_datatype_finitizable) @
   449       (shallow_dataTs |> filter_out (is_finite_type hol_ctxt)
   450                       |> filter is_shallow_datatype_finitizable)
   451     val _ =
   452       if verbose andalso not (null finitizable_dataTs) then
   453         pprint_v (K (monotonicity_message finitizable_dataTs
   454                          "Nitpick can use a more precise finite encoding."))
   455       else
   456         ()
   457     (* This detection code is an ugly hack. Fortunately, it is used only to
   458        provide a hint to the user. *)
   459     fun is_struct_induct_step (name, (Rule_Cases.Case {fixes, assumes, ...}, _)) =
   460       not (null fixes) andalso
   461       exists (String.isSuffix ".hyps" o Name_Space.full_name Name_Space.default_naming o fst) assumes andalso
   462       exists (exists (curry (op =) name o shortest_name o fst)
   463               o datatype_constrs hol_ctxt) deep_dataTs
   464     val likely_in_struct_induct_step =
   465       exists is_struct_induct_step (Proof_Context.dest_cases ctxt)
   466     val _ = if standard andalso likely_in_struct_induct_step then
   467               pprint_nt (fn () => Pretty.blk (0,
   468                   pstrs "Hint: To check that the induction hypothesis is \
   469                         \general enough, try this command: " @
   470                   [Pretty.mark
   471                     (Active.make_markup Markup.sendbackN
   472                       {implicit = false, properties = [Markup.padding_command]})
   473                     (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 _ = check_arity guiltiest_party min_univ_card min_highest_arity
   550 
   551         val def_us =
   552           def_us |> map (choose_reps_in_nut scope unsound rep_table true)
   553         val nondef_us =
   554           nondef_us |> map (choose_reps_in_nut scope unsound rep_table false)
   555         val need_us =
   556           need_us |> map (choose_reps_in_nut scope unsound rep_table false)
   557 (*
   558         val _ = List.app (print_g o string_for_nut ctxt)
   559                          (free_names @ sel_names @ nonsel_names @
   560                           nondef_us @ def_us @ need_us)
   561 *)
   562         val (free_rels, pool, rel_table) =
   563           rename_free_vars free_names initial_pool NameTable.empty
   564         val (sel_rels, pool, rel_table) =
   565           rename_free_vars sel_names pool rel_table
   566         val (other_rels, pool, rel_table) =
   567           rename_free_vars nonsel_names pool rel_table
   568         val nondef_us = nondef_us |> map (rename_vars_in_nut pool rel_table)
   569         val def_us = def_us |> map (rename_vars_in_nut pool rel_table)
   570         val need_us = need_us |> map (rename_vars_in_nut pool rel_table)
   571         val nondef_fs = map (kodkod_formula_from_nut ofs kk) nondef_us
   572         val def_fs = map (kodkod_formula_from_nut ofs kk) def_us
   573         val formula = fold (fold s_and) [def_fs, nondef_fs] KK.True
   574         val comment = (if unsound then "unsound" else "sound") ^ "\n" ^
   575                       Print_Mode.setmp [] multiline_string_for_scope scope
   576         val kodkod_sat_solver =
   577           Kodkod_SAT.sat_solver_spec actual_sat_solver |> snd
   578         val bit_width = if bits = 0 then 16 else bits + 1
   579         val delay =
   580           if unsound then
   581             unsound_delay_for_timeout (Time.- (deadline, Time.now ()))
   582           else
   583             0
   584         val settings = [("solver", commas_quote kodkod_sat_solver),
   585                         ("bit_width", string_of_int bit_width),
   586                         ("symmetry_breaking", string_of_int kodkod_sym_break),
   587                         ("sharing", "3"),
   588                         ("flatten", "false"),
   589                         ("delay", signed_string_of_int delay)]
   590         val plain_rels = free_rels @ other_rels
   591         val plain_bounds = map (bound_for_plain_rel ctxt debug) plain_rels
   592         val plain_axioms = map (declarative_axiom_for_plain_rel kk) plain_rels
   593         val need_vals =
   594           map (fn dtype as {typ, ...} =>
   595                   (typ, needed_values_for_datatype need_us ofs dtype)) datatypes
   596         val sel_bounds =
   597           map (bound_for_sel_rel ctxt debug need_vals datatypes) sel_rels
   598         val dtype_axioms =
   599           declarative_axioms_for_datatypes hol_ctxt binarize need_us need_vals
   600               datatype_sym_break bits ofs kk rel_table datatypes
   601         val declarative_axioms = plain_axioms @ dtype_axioms
   602         val univ_card = Int.max (univ_card nat_card int_card main_j0
   603                                      (plain_bounds @ sel_bounds) formula,
   604                                  main_j0 |> bits > 0 ? Integer.add (bits + 1))
   605         val (built_in_bounds, built_in_axioms) =
   606           bounds_and_axioms_for_built_in_rels_in_formulas debug univ_card
   607               nat_card int_card main_j0 (formula :: declarative_axioms)
   608         val bounds = built_in_bounds @ plain_bounds @ sel_bounds
   609                      |> not debug ? merge_bounds
   610         val axioms = built_in_axioms @ declarative_axioms
   611         val highest_arity =
   612           fold Integer.max (map (fst o fst) (maps fst bounds)) 0
   613         val formula = fold_rev s_and axioms formula
   614         val _ = if bits = 0 then () else check_bits bits formula
   615         val _ = if formula = KK.False then ()
   616                 else check_arity "" univ_card highest_arity
   617       in
   618         SOME ({comment = comment, settings = settings, univ_card = univ_card,
   619                tuple_assigns = [], bounds = bounds,
   620                int_bounds = if bits = 0 then sequential_int_bounds univ_card
   621                             else pow_of_two_int_bounds bits main_j0,
   622                expr_assigns = [], formula = formula},
   623               {free_names = free_names, sel_names = sel_names,
   624                nonsel_names = nonsel_names, rel_table = rel_table,
   625                unsound = unsound, scope = scope})
   626       end
   627       handle TOO_LARGE (loc, msg) =>
   628              if loc = "Nitpick_Kodkod.check_arity" andalso
   629                 not (Typtab.is_empty ofs) then
   630                problem_for_scope unsound
   631                    {hol_ctxt = hol_ctxt, binarize = binarize,
   632                     card_assigns = card_assigns, bits = bits,
   633                     bisim_depth = bisim_depth, datatypes = datatypes,
   634                     ofs = Typtab.empty}
   635              else if loc = "Nitpick.pick_them_nits_in_term.\
   636                            \problem_for_scope" then
   637                NONE
   638              else
   639                (Unsynchronized.change too_big_scopes (cons scope);
   640                 print_v (fn () =>
   641                     "Limit reached: " ^ msg ^ ". Skipping " ^
   642                     (if unsound then "potential component of " else "") ^
   643                     "scope.");
   644                 NONE)
   645            | TOO_SMALL (_, msg) =>
   646              (print_v (fn () =>
   647                   "Limit reached: " ^ msg ^ ". Skipping " ^
   648                   (if unsound then "potential component of " else "") ^
   649                   "scope.");
   650               NONE)
   651 
   652     val das_wort_model =
   653       (if falsify then "counterexample" else "model")
   654       |> not standard ? prefix "nonstandard "
   655 
   656     val scopes = Unsynchronized.ref []
   657     val generated_scopes = Unsynchronized.ref []
   658     val generated_problems = Unsynchronized.ref ([] : rich_problem list)
   659     val checked_problems = Unsynchronized.ref (SOME [])
   660     val met_potential = Unsynchronized.ref 0
   661 
   662     fun update_checked_problems problems =
   663       List.app (Unsynchronized.change checked_problems o Option.map o cons
   664                 o nth problems)
   665     fun show_kodkod_warning "" = ()
   666       | show_kodkod_warning s = print_nt (fn () => "Kodkod warning: " ^ s ^ ".")
   667 
   668     fun print_and_check_model genuine bounds
   669             ({free_names, sel_names, nonsel_names, rel_table, scope, ...}
   670              : problem_extension) =
   671       let
   672         val _ =
   673           print_t (fn () =>
   674                "% SZS status " ^
   675                (if genuine then
   676                   if falsify then "CounterSatisfiable" else "Satisfiable"
   677                 else
   678                   "Unknown") ^ "\n" ^
   679                "% SZS output start FiniteModel")
   680         val (reconstructed_model, codatatypes_ok) =
   681           reconstruct_hol_model
   682               {show_datatypes = show_datatypes, show_skolems = show_skolems,
   683                show_consts = show_consts}
   684               scope formats atomss real_frees pseudo_frees free_names sel_names
   685               nonsel_names rel_table bounds
   686         val genuine_means_genuine =
   687           got_all_user_axioms andalso none_true wfs andalso
   688           sound_finitizes andalso total_consts <> SOME true andalso
   689           codatatypes_ok
   690         fun assms_prop () =
   691           Logic.mk_conjunction_list (neg_t :: def_assm_ts @ nondef_assm_ts)
   692       in
   693         (pprint_a (Pretty.chunks
   694              [Pretty.blk (0,
   695                   (pstrs ((if mode = Auto_Try then "Auto " else "") ^
   696                           "Nitpick found a" ^
   697                           (if not genuine then " potentially spurious "
   698                            else if genuine_means_genuine then " "
   699                            else " quasi genuine ") ^ das_wort_model) @
   700                    (case pretties_for_scope scope verbose of
   701                       [] => []
   702                     | pretties => pstrs " for " @ pretties) @
   703                    [Pretty.str ":\n"])),
   704               Pretty.indent indent_size reconstructed_model]);
   705          print_t (K "% SZS output end FiniteModel");
   706          if genuine then
   707            (if check_genuine andalso standard then
   708               case prove_hol_model scope tac_timeout free_names sel_names
   709                                    rel_table bounds (assms_prop ()) of
   710                 SOME true =>
   711                 print ("Confirmation by \"auto\": The above " ^
   712                        das_wort_model ^ " is really genuine.")
   713               | SOME false =>
   714                 if genuine_means_genuine then
   715                   error ("A supposedly genuine " ^ das_wort_model ^ " was \
   716                          \shown to be spurious by \"auto\".\nThis should never \
   717                          \happen.\nPlease send a bug report to blanchet\
   718                          \te@in.tum.de.")
   719                  else
   720                    print ("Refutation by \"auto\": The above " ^
   721                           das_wort_model ^ " is spurious.")
   722                | NONE => print "No confirmation by \"auto\"."
   723             else
   724               ();
   725             if not standard andalso likely_in_struct_induct_step then
   726               print "The existence of a nonstandard model suggests that the \
   727                     \induction hypothesis is not general enough or may even be \
   728                     \wrong. See the Nitpick manual's \"Inductive Properties\" \
   729                     \section for details (\"isabelle doc nitpick\")."
   730             else
   731               ();
   732             if has_lonely_bool_var orig_t then
   733               print "Hint: Maybe you forgot a colon after the lemma's name?"
   734             else if has_syntactic_sorts orig_t then
   735               print "Hint: Maybe you forgot a type constraint?"
   736             else
   737               ();
   738             if not genuine_means_genuine then
   739               if no_poly_user_axioms then
   740                 let
   741                   val options =
   742                     [] |> not got_all_mono_user_axioms
   743                           ? cons ("user_axioms", "\"true\"")
   744                        |> not (none_true wfs)
   745                           ? cons ("wf", "\"smart\" or \"false\"")
   746                        |> not sound_finitizes
   747                           ? cons ("finitize", "\"smart\" or \"false\"")
   748                        |> total_consts = SOME true
   749                           ? cons ("total_consts", "\"smart\" or \"false\"")
   750                        |> not codatatypes_ok
   751                           ? cons ("bisim_depth", "a nonnegative value")
   752                   val ss =
   753                     map (fn (name, value) => quote name ^ " set to " ^ value)
   754                         options
   755                 in
   756                   print ("Try again with " ^
   757                          space_implode " " (serial_commas "and" ss) ^
   758                          " to confirm that the " ^ das_wort_model ^
   759                          " is genuine.")
   760                 end
   761               else
   762                 print ("Nitpick is unable to guarantee the authenticity of \
   763                        \the " ^ das_wort_model ^ " in the presence of \
   764                        \polymorphic axioms.")
   765             else
   766               ();
   767             NONE)
   768          else
   769            if not genuine then
   770              (Unsynchronized.inc met_potential;
   771               if check_potential then
   772                 let
   773                   val status = prove_hol_model scope tac_timeout free_names
   774                                                sel_names rel_table bounds
   775                                                (assms_prop ())
   776                 in
   777                   (case status of
   778                      SOME true => print ("Confirmation by \"auto\": The \
   779                                          \above " ^ das_wort_model ^
   780                                          " is genuine.")
   781                    | SOME false => print ("Refutation by \"auto\": The above " ^
   782                                           das_wort_model ^ " is spurious.")
   783                    | NONE => print "No confirmation by \"auto\".");
   784                   status
   785                 end
   786               else
   787                 NONE)
   788            else
   789              NONE)
   790         |> pair genuine_means_genuine
   791       end
   792     fun solve_any_problem (found_really_genuine, max_potential, max_genuine,
   793                            donno) first_time problems =
   794       let
   795         val max_potential = Int.max (0, max_potential)
   796         val max_genuine = Int.max (0, max_genuine)
   797         fun print_and_check genuine (j, bounds) =
   798           print_and_check_model genuine bounds (snd (nth problems j))
   799         val max_solutions = max_potential + max_genuine
   800                             |> not incremental ? Integer.min 1
   801       in
   802         if max_solutions <= 0 then
   803           (found_really_genuine, 0, 0, donno)
   804         else
   805           case KK.solve_any_problem debug overlord deadline max_threads
   806                                     max_solutions (map fst problems) of
   807             KK.JavaNotFound =>
   808             (print_nt java_not_found_message;
   809              (found_really_genuine, max_potential, max_genuine, donno + 1))
   810           | KK.JavaTooOld =>
   811             (print_nt java_too_old_message;
   812              (found_really_genuine, max_potential, max_genuine, donno + 1))
   813           | KK.KodkodiNotInstalled =>
   814             (print_nt kodkodi_not_installed_message;
   815              (found_really_genuine, max_potential, max_genuine, donno + 1))
   816           | KK.KodkodiTooOld =>
   817             (print_nt kodkodi_too_old_message;
   818              (found_really_genuine, max_potential, max_genuine, donno + 1))
   819           | KK.Normal ([], unsat_js, s) =>
   820             (update_checked_problems problems unsat_js; show_kodkod_warning s;
   821              (found_really_genuine, max_potential, max_genuine, donno))
   822           | KK.Normal (sat_ps, unsat_js, s) =>
   823             let
   824               val (lib_ps, con_ps) =
   825                 List.partition (#unsound o snd o nth problems o fst) sat_ps
   826             in
   827               update_checked_problems problems (unsat_js @ map fst lib_ps);
   828               show_kodkod_warning s;
   829               if null con_ps then
   830                 let
   831                   val genuine_codes =
   832                     lib_ps |> take max_potential
   833                            |> map (print_and_check false)
   834                            |> filter (curry (op =) (SOME true) o snd)
   835                   val found_really_genuine =
   836                     found_really_genuine orelse exists fst genuine_codes
   837                   val num_genuine = length genuine_codes
   838                   val max_genuine = max_genuine - num_genuine
   839                   val max_potential = max_potential
   840                                       - (length lib_ps - num_genuine)
   841                 in
   842                   if max_genuine <= 0 then
   843                     (found_really_genuine, 0, 0, donno)
   844                   else
   845                     let
   846                       (* "co_js" is the list of sound problems whose unsound
   847                          pendants couldn't be satisfied and hence that most
   848                          probably can't be satisfied themselves. *)
   849                       val co_js =
   850                         map (fn j => j - 1) unsat_js
   851                         |> filter (fn j =>
   852                                       j >= 0 andalso
   853                                       scopes_equivalent
   854                                           (#scope (snd (nth problems j)),
   855                                            #scope (snd (nth problems (j + 1)))))
   856                       val bye_js = sort_distinct int_ord (map fst sat_ps @
   857                                                           unsat_js @ co_js)
   858                       val problems =
   859                         problems |> filter_out_indices bye_js
   860                                  |> max_potential <= 0
   861                                     ? filter_out (#unsound o snd)
   862                     in
   863                       solve_any_problem (found_really_genuine, max_potential,
   864                                          max_genuine, donno) false problems
   865                     end
   866                 end
   867               else
   868                 let
   869                   val genuine_codes =
   870                     con_ps |> take max_genuine
   871                            |> map (print_and_check true)
   872                   val max_genuine = max_genuine - length genuine_codes
   873                   val found_really_genuine =
   874                     found_really_genuine orelse exists fst genuine_codes
   875                 in
   876                   if max_genuine <= 0 orelse not first_time then
   877                     (found_really_genuine, 0, max_genuine, donno)
   878                   else
   879                     let
   880                       val bye_js = sort_distinct int_ord
   881                                                  (map fst sat_ps @ unsat_js)
   882                       val problems =
   883                         problems |> filter_out_indices bye_js
   884                                  |> filter_out (#unsound o snd)
   885                     in
   886                       solve_any_problem (found_really_genuine, 0, max_genuine,
   887                                          donno) false problems
   888                     end
   889                 end
   890             end
   891           | KK.TimedOut unsat_js =>
   892             (update_checked_problems problems unsat_js; raise TimeLimit.TimeOut)
   893           | KK.Error (s, unsat_js) =>
   894             (update_checked_problems problems unsat_js;
   895              print_v (K ("Kodkod error: " ^ s ^ "."));
   896              (found_really_genuine, max_potential, max_genuine, donno + 1))
   897       end
   898 
   899     fun run_batch j n scopes (found_really_genuine, max_potential, max_genuine,
   900                               donno) =
   901       let
   902         val _ =
   903           if null scopes then
   904             print_nt (K "The scope specification is inconsistent.")
   905           else if verbose then
   906             pprint_nt (fn () => Pretty.chunks
   907                 [Pretty.blk (0,
   908                      pstrs ((if n > 1 then
   909                                "Batch " ^ string_of_int (j + 1) ^ " of " ^
   910                                signed_string_of_int n ^ ": "
   911                              else
   912                                "") ^
   913                             "Trying " ^ string_of_int (length scopes) ^
   914                             " scope" ^ plural_s_for_list scopes ^ ":")),
   915                  Pretty.indent indent_size
   916                      (Pretty.chunks (map2
   917                           (fn j => fn scope =>
   918                               Pretty.block (
   919                                   (case pretties_for_scope scope true of
   920                                      [] => [Pretty.str "Empty"]
   921                                    | pretties => pretties) @
   922                                   [Pretty.str (if j = 1 then "." else ";")]))
   923                           (length scopes downto 1) scopes))])
   924           else
   925             ()
   926         fun add_problem_for_scope (scope, unsound) (problems, donno) =
   927           (check_deadline ();
   928            case problem_for_scope unsound scope of
   929              SOME problem =>
   930              (problems
   931               |> (null problems orelse
   932                   not (KK.problems_equivalent (fst problem, fst (hd problems))))
   933                   ? cons problem, donno)
   934            | NONE => (problems, donno + 1))
   935         val (problems, donno) =
   936           fold add_problem_for_scope
   937                (map_product pair scopes
   938                     ((if max_genuine > 0 then [false] else []) @
   939                      (if max_potential > 0 then [true] else [])))
   940                ([], donno)
   941         val _ = Unsynchronized.change generated_problems (append problems)
   942         val _ = Unsynchronized.change generated_scopes (append scopes)
   943         val _ =
   944           if j + 1 = n then
   945             let
   946               val (unsound_problems, sound_problems) =
   947                 List.partition (#unsound o snd) (!generated_problems)
   948             in
   949               if not (null sound_problems) andalso
   950                  forall (KK.is_problem_trivially_false o fst)
   951                         sound_problems then
   952                 print_nt (fn () =>
   953                     "Warning: The conjecture " ^
   954                     (if falsify then "either trivially holds"
   955                      else "is either trivially unsatisfiable") ^
   956                     " for the given scopes or lies outside Nitpick's supported \
   957                     \fragment." ^
   958                     (if exists (not o KK.is_problem_trivially_false o fst)
   959                                unsound_problems then
   960                        " Only potentially spurious " ^ das_wort_model ^
   961                        "s may be found."
   962                      else
   963                        ""))
   964               else
   965                 ()
   966             end
   967           else
   968             ()
   969       in
   970         solve_any_problem (found_really_genuine, max_potential, max_genuine,
   971                            donno) true (rev problems)
   972       end
   973 
   974     fun scope_count (problems : rich_problem list) scope =
   975       length (filter (curry scopes_equivalent scope o #scope o snd) problems)
   976     fun excipit did_so_and_so =
   977       let
   978         val do_filter =
   979           if !met_potential = max_potential then filter_out (#unsound o snd)
   980           else I
   981         val total = length (!scopes)
   982         val unsat =
   983           fold (fn scope =>
   984                    case scope_count (do_filter (!generated_problems)) scope of
   985                      0 => I
   986                    | n =>
   987                      scope_count (do_filter (these (!checked_problems)))
   988                                  scope = n
   989                      ? Integer.add 1) (!generated_scopes) 0
   990       in
   991         (if mode = TPTP then "% SZS status Unknown\n" else "") ^
   992         "Nitpick " ^ did_so_and_so ^
   993         (if is_some (!checked_problems) andalso total > 0 then
   994            " " ^ string_of_int unsat ^ " of " ^ string_of_int total ^ " scope"
   995            ^ plural_s total
   996          else
   997            "") ^ "."
   998       end
   999 
  1000     val (skipped, the_scopes) =
  1001       all_scopes hol_ctxt binarize cards_assigns maxes_assigns iters_assigns
  1002                  bitss bisim_depths mono_Ts nonmono_Ts deep_dataTs
  1003                  finitizable_dataTs
  1004     val _ = if skipped > 0 then
  1005               print_nt (fn () => "Too many scopes. Skipping " ^
  1006                                  string_of_int skipped ^ " scope" ^
  1007                                  plural_s skipped ^
  1008                                  ". (Consider using \"mono\" or \
  1009                                  \\"merge_type_vars\" to prevent this.)")
  1010             else
  1011               ()
  1012     val _ = scopes := the_scopes
  1013 
  1014     fun run_batches _ _ []
  1015                     (found_really_genuine, max_potential, max_genuine, donno) =
  1016         if donno > 0 andalso max_genuine > 0 then
  1017           (print_nt (fn () => excipit "checked"); unknownN)
  1018         else if max_genuine = original_max_genuine then
  1019           if max_potential = original_max_potential then
  1020             (print_t (K "% SZS status Unknown");
  1021              print_nt (fn () =>
  1022                  "Nitpick found no " ^ das_wort_model ^ "." ^
  1023                  (if not standard andalso likely_in_struct_induct_step then
  1024                     " This suggests that the induction hypothesis might be \
  1025                     \general enough to prove this subgoal."
  1026                   else
  1027                     "")); if skipped > 0 then unknownN else noneN)
  1028           else
  1029             (print_nt (fn () =>
  1030                  excipit ("could not find a" ^
  1031                           (if max_genuine = 1 then
  1032                              " better " ^ das_wort_model ^ "."
  1033                            else
  1034                              "ny better " ^ das_wort_model ^ "s.") ^
  1035                           " It checked"));
  1036              potentialN)
  1037         else if found_really_genuine then
  1038           genuineN
  1039         else
  1040           quasi_genuineN
  1041       | run_batches j n (batch :: batches) z =
  1042         let val (z as (_, _, max_genuine, _)) = run_batch j n batch z in
  1043           run_batches (j + 1) n (if max_genuine > 0 then batches else []) z
  1044         end
  1045 
  1046     val batches = chunk_list batch_size (!scopes)
  1047     val outcome_code =
  1048       run_batches 0 (length batches) batches
  1049                   (false, max_potential, max_genuine, 0)
  1050       handle TimeLimit.TimeOut =>
  1051              (print_nt (fn () => excipit "ran out of time after checking");
  1052               if !met_potential > 0 then potentialN else unknownN)
  1053     val _ = print_v (fn () =>
  1054                 "Total time: " ^ string_of_time (Timer.checkRealTimer timer) ^
  1055                 ".")
  1056     val _ = spying spy (fn () => (state, i, "outcome: " ^ outcome_code))
  1057   in (outcome_code, !state_ref) end
  1058 
  1059 (* Give the inner timeout a chance. *)
  1060 val timeout_bonus = seconds 1.0
  1061 
  1062 fun pick_nits_in_term state (params as {debug, timeout, expect, ...}) mode i n
  1063                       step subst def_assm_ts nondef_assm_ts orig_t =
  1064   let
  1065     val print_nt = if is_mode_nt mode then Output.urgent_message else K ()
  1066     val print_t = if mode = TPTP then Output.urgent_message else K ()
  1067   in
  1068     if getenv "KODKODI" = "" then
  1069       (* The "expect" argument is deliberately ignored if Kodkodi is missing so
  1070          that the "Nitpick_Examples" can be processed on any machine. *)
  1071       (print_nt (Pretty.string_of (plazy kodkodi_not_installed_message));
  1072        ("no_kodkodi", state))
  1073     else
  1074       let
  1075         val unknown_outcome = (unknownN, state)
  1076         val deadline = Time.+ (Time.now (), timeout)
  1077         val outcome as (outcome_code, _) =
  1078           TimeLimit.timeLimit (Time.+ (timeout, timeout_bonus))
  1079               (pick_them_nits_in_term deadline state params mode i n step subst
  1080                                       def_assm_ts nondef_assm_ts) orig_t
  1081           handle TOO_LARGE (_, details) =>
  1082                  (print_t "% SZS status Unknown";
  1083                   print_nt ("Limit reached: " ^ details ^ "."); unknown_outcome)
  1084                | TOO_SMALL (_, details) =>
  1085                  (print_t "% SZS status Unknown";
  1086                   print_nt ("Limit reached: " ^ details ^ "."); unknown_outcome)
  1087                | Kodkod.SYNTAX (_, details) =>
  1088                  (print_t "% SZS status Unknown";
  1089                   print_nt ("Malformed Kodkodi output: " ^ details ^ ".");
  1090                   unknown_outcome)
  1091                | TimeLimit.TimeOut =>
  1092                  (print_t "% SZS status TimedOut";
  1093                   print_nt "Nitpick ran out of time."; unknown_outcome)
  1094       in
  1095         if expect = "" orelse outcome_code = expect then outcome
  1096         else error ("Unexpected outcome: " ^ quote outcome_code ^ ".")
  1097       end
  1098   end
  1099 
  1100 fun is_fixed_equation ctxt
  1101                       (Const (@{const_name "=="}, _) $ Free (s, _) $ Const _) =
  1102     Variable.is_fixed ctxt s
  1103   | is_fixed_equation _ _ = false
  1104 fun extract_fixed_frees ctxt (assms, t) =
  1105   let
  1106     val (subst, other_assms) =
  1107       List.partition (is_fixed_equation ctxt) assms
  1108       |>> map Logic.dest_equals
  1109   in (subst, other_assms, subst_atomic subst t) end
  1110 
  1111 fun pick_nits_in_subgoal state params mode i step =
  1112   let
  1113     val ctxt = Proof.context_of state
  1114     val t = state |> Proof.raw_goal |> #goal |> prop_of
  1115   in
  1116     case Logic.count_prems t of
  1117       0 => (Output.urgent_message "No subgoal!"; (noneN, state))
  1118     | n =>
  1119       let
  1120         val t = Logic.goal_params t i |> fst
  1121         val assms = map term_of (Assumption.all_assms_of ctxt)
  1122         val (subst, assms, t) = extract_fixed_frees ctxt (assms, t)
  1123       in pick_nits_in_term state params mode i n step subst [] assms t end
  1124   end
  1125 
  1126 end;