src/HOL/Tools/Sledgehammer/sledgehammer_atp_translate.ML
author blanchet
Thu Mar 17 11:18:31 2011 +0100 (2011-03-17)
changeset 41990 7f2793d51efc
parent 41770 a710e96583d5
child 42180 a6c141925a8a
permissions -rw-r--r--
add option to function to keep trivial ATP formulas, needed for some experiments
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(*  Title:      HOL/Tools/Sledgehammer/sledgehammer_atp_translate.ML
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    Author:     Fabian Immler, TU Muenchen
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    Author:     Makarius
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    Author:     Jasmin Blanchette, TU Muenchen
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Translation of HOL to FOL for Sledgehammer.
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*)
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signature SLEDGEHAMMER_ATP_TRANSLATE =
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sig
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  type 'a problem = 'a ATP_Problem.problem
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  type translated_formula
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  datatype type_system =
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    Tags of bool |
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    Preds of bool |
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    Const_Args |
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    No_Types
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  val precise_overloaded_args : bool Unsynchronized.ref
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  val fact_prefix : string
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  val conjecture_prefix : string
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  val types_dangerous_types : type_system -> bool
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  val num_atp_type_args : theory -> type_system -> string -> int
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  val translate_atp_fact :
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    Proof.context -> bool -> (string * 'a) * thm
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    -> translated_formula option * ((string * 'a) * thm)
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  val prepare_atp_problem :
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    Proof.context -> bool -> bool -> type_system -> bool -> term list -> term
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    -> (translated_formula option * ((string * 'a) * thm)) list
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    -> string problem * string Symtab.table * int * (string * 'a) list vector
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  val atp_problem_weights : string problem -> (string * real) list
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end;
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structure Sledgehammer_ATP_Translate : SLEDGEHAMMER_ATP_TRANSLATE =
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struct
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open ATP_Problem
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open Metis_Translate
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open Sledgehammer_Util
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(* FIXME: Remove references once appropriate defaults have been determined
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   empirically. *)
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val precise_overloaded_args = Unsynchronized.ref false
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val fact_prefix = "fact_"
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val conjecture_prefix = "conj_"
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val helper_prefix = "help_"
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val class_rel_clause_prefix = "clrel_";
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val arity_clause_prefix = "arity_"
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val tfree_prefix = "tfree_"
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(* Freshness almost guaranteed! *)
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val sledgehammer_weak_prefix = "Sledgehammer:"
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type translated_formula =
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  {name: string,
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   kind: kind,
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   combformula: (name, combterm) formula,
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   ctypes_sorts: typ list}
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datatype type_system =
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  Tags of bool |
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  Preds of bool |
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  Const_Args |
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  No_Types
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fun types_dangerous_types (Tags _) = true
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  | types_dangerous_types (Preds _) = true
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  | types_dangerous_types _ = false
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(* This is an approximation. If it returns "true" for a constant that isn't
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   overloaded (i.e., that has one uniform definition), needless clutter is
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   generated; if it returns "false" for an overloaded constant, the ATP gets a
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   license to do unsound reasoning if the type system is "overloaded_args". *)
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fun is_overloaded thy s =
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  not (s = @{const_name HOL.eq}) andalso
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  not (s = @{const_name Metis.fequal}) andalso
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  (not (!precise_overloaded_args) orelse s = @{const_name finite} orelse
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   length (Defs.specifications_of (Theory.defs_of thy) s) > 1)
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fun needs_type_args thy type_sys s =
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  case type_sys of
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    Tags full_types => not full_types andalso is_overloaded thy s
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  | Preds _ => is_overloaded thy s (* FIXME: could be more precise *)
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  | Const_Args => is_overloaded thy s
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  | No_Types => false
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fun num_atp_type_args thy type_sys s =
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  if needs_type_args thy type_sys s then num_type_args thy s else 0
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fun atp_type_literals_for_types type_sys Ts =
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  if type_sys = No_Types then [] else type_literals_for_types Ts
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fun mk_anot phi = AConn (ANot, [phi])
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fun mk_aconn c phi1 phi2 = AConn (c, [phi1, phi2])
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fun mk_ahorn [] phi = phi
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  | mk_ahorn (phi :: phis) psi =
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    AConn (AImplies, [fold (mk_aconn AAnd) phis phi, psi])
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fun close_universally phi =
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  let
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    fun term_vars bounds (ATerm (name as (s, _), tms)) =
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        (is_atp_variable s andalso not (member (op =) bounds name))
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          ? insert (op =) name
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        #> fold (term_vars bounds) tms
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    fun formula_vars bounds (AQuant (_, xs, phi)) =
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        formula_vars (xs @ bounds) phi
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      | formula_vars bounds (AConn (_, phis)) = fold (formula_vars bounds) phis
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      | formula_vars bounds (AAtom tm) = term_vars bounds tm
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  in
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    case formula_vars [] phi [] of [] => phi | xs => AQuant (AForall, xs, phi)
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  end
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fun combformula_for_prop thy eq_as_iff =
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  let
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    fun do_term bs t ts =
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      combterm_from_term thy bs (Envir.eta_contract t)
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      |>> AAtom ||> union (op =) ts
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    fun do_quant bs q s T t' =
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      let val s = Name.variant (map fst bs) s in
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        do_formula ((s, T) :: bs) t'
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        #>> (fn phi => AQuant (q, [`make_bound_var s], phi))
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      end
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    and do_conn bs c t1 t2 =
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      do_formula bs t1 ##>> do_formula bs t2
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      #>> (fn (phi1, phi2) => AConn (c, [phi1, phi2]))
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    and do_formula bs t =
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      case t of
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        @{const Not} $ t1 =>
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        do_formula bs t1 #>> (fn phi => AConn (ANot, [phi]))
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      | Const (@{const_name All}, _) $ Abs (s, T, t') =>
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        do_quant bs AForall s T t'
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      | Const (@{const_name Ex}, _) $ Abs (s, T, t') =>
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        do_quant bs AExists s T t'
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      | @{const HOL.conj} $ t1 $ t2 => do_conn bs AAnd t1 t2
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      | @{const HOL.disj} $ t1 $ t2 => do_conn bs AOr t1 t2
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      | @{const HOL.implies} $ t1 $ t2 => do_conn bs AImplies t1 t2
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      | Const (@{const_name HOL.eq}, Type (_, [@{typ bool}, _])) $ t1 $ t2 =>
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        if eq_as_iff then do_conn bs AIff t1 t2 else do_term bs t
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      | _ => do_term bs t
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  in do_formula [] end
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val presimplify_term = prop_of o Meson.presimplify oo Skip_Proof.make_thm
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fun concealed_bound_name j = sledgehammer_weak_prefix ^ string_of_int j
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fun conceal_bounds Ts t =
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  subst_bounds (map (Free o apfst concealed_bound_name)
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                    (0 upto length Ts - 1 ~~ Ts), t)
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fun reveal_bounds Ts =
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  subst_atomic (map (fn (j, T) => (Free (concealed_bound_name j, T), Bound j))
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                    (0 upto length Ts - 1 ~~ Ts))
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(* Removes the lambdas from an equation of the form "t = (%x. u)".
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   (Cf. "extensionalize_theorem" in "Meson_Clausify".) *)
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fun extensionalize_term t =
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  let
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    fun aux j (@{const Trueprop} $ t') = @{const Trueprop} $ aux j t'
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      | aux j (t as Const (s, Type (_, [Type (_, [_, T']),
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                                        Type (_, [_, res_T])]))
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                    $ t2 $ Abs (var_s, var_T, t')) =
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        if s = @{const_name HOL.eq} orelse s = @{const_name "=="} then
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          let val var_t = Var ((var_s, j), var_T) in
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            Const (s, T' --> T' --> res_T)
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              $ betapply (t2, var_t) $ subst_bound (var_t, t')
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            |> aux (j + 1)
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          end
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        else
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          t
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      | aux _ t = t
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  in aux (maxidx_of_term t + 1) t end
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fun introduce_combinators_in_term ctxt kind t =
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  let val thy = ProofContext.theory_of ctxt in
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    if Meson.is_fol_term thy t then
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      t
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    else
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      let
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        fun aux Ts t =
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          case t of
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            @{const Not} $ t1 => @{const Not} $ aux Ts t1
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          | (t0 as Const (@{const_name All}, _)) $ Abs (s, T, t') =>
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            t0 $ Abs (s, T, aux (T :: Ts) t')
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          | (t0 as Const (@{const_name All}, _)) $ t1 =>
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            aux Ts (t0 $ eta_expand Ts t1 1)
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          | (t0 as Const (@{const_name Ex}, _)) $ Abs (s, T, t') =>
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            t0 $ Abs (s, T, aux (T :: Ts) t')
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          | (t0 as Const (@{const_name Ex}, _)) $ t1 =>
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            aux Ts (t0 $ eta_expand Ts t1 1)
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          | (t0 as @{const HOL.conj}) $ t1 $ t2 => t0 $ aux Ts t1 $ aux Ts t2
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          | (t0 as @{const HOL.disj}) $ t1 $ t2 => t0 $ aux Ts t1 $ aux Ts t2
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          | (t0 as @{const HOL.implies}) $ t1 $ t2 => t0 $ aux Ts t1 $ aux Ts t2
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          | (t0 as Const (@{const_name HOL.eq}, Type (_, [@{typ bool}, _])))
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              $ t1 $ t2 =>
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            t0 $ aux Ts t1 $ aux Ts t2
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          | _ => if not (exists_subterm (fn Abs _ => true | _ => false) t) then
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                   t
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                 else
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                   t |> conceal_bounds Ts
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                     |> Envir.eta_contract
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                     |> cterm_of thy
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                     |> Meson_Clausify.introduce_combinators_in_cterm
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                     |> prop_of |> Logic.dest_equals |> snd
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                     |> reveal_bounds Ts
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        val (t, ctxt') = Variable.import_terms true [t] ctxt |>> the_single
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      in t |> aux [] |> singleton (Variable.export_terms ctxt' ctxt) end
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      handle THM _ =>
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             (* A type variable of sort "{}" will make abstraction fail. *)
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             if kind = Conjecture then HOLogic.false_const
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             else HOLogic.true_const
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  end
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(* Metis's use of "resolve_tac" freezes the schematic variables. We simulate the
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   same in Sledgehammer to prevent the discovery of unreplable proofs. *)
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fun freeze_term t =
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  let
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    fun aux (t $ u) = aux t $ aux u
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      | aux (Abs (s, T, t)) = Abs (s, T, aux t)
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      | aux (Var ((s, i), T)) =
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        Free (sledgehammer_weak_prefix ^ s ^ "_" ^ string_of_int i, T)
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      | aux t = t
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  in t |> exists_subterm is_Var t ? aux end
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(* making fact and conjecture formulas *)
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fun make_formula ctxt eq_as_iff presimp name kind t =
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  let
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    val thy = ProofContext.theory_of ctxt
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    val t = t |> Envir.beta_eta_contract
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              |> transform_elim_term
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              |> Object_Logic.atomize_term thy
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    val need_trueprop = (fastype_of t = HOLogic.boolT)
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    val t = t |> need_trueprop ? HOLogic.mk_Trueprop
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              |> extensionalize_term
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              |> presimp ? presimplify_term thy
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              |> perhaps (try (HOLogic.dest_Trueprop))
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              |> introduce_combinators_in_term ctxt kind
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              |> kind <> Axiom ? freeze_term
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    val (combformula, ctypes_sorts) = combformula_for_prop thy eq_as_iff t []
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  in
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    {name = name, combformula = combformula, kind = kind,
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     ctypes_sorts = ctypes_sorts}
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  end
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fun make_fact ctxt keep_trivial eq_as_iff presimp ((name, _), th) =
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  case (keep_trivial,
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        make_formula ctxt eq_as_iff presimp name Axiom (prop_of th)) of
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    (false, {combformula = AAtom (CombConst (("c_True", _), _, _)), ...}) =>
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    NONE
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  | (_, formula) => SOME formula
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fun make_conjecture ctxt ts =
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  let val last = length ts - 1 in
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    map2 (fn j => make_formula ctxt true true (string_of_int j)
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                               (if j = last then Conjecture else Hypothesis))
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         (0 upto last) ts
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  end
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(** Helper facts **)
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fun fold_formula f (AQuant (_, _, phi)) = fold_formula f phi
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  | fold_formula f (AConn (_, phis)) = fold (fold_formula f) phis
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  | fold_formula f (AAtom tm) = f tm
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fun count_term (ATerm ((s, _), tms)) =
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  (if is_atp_variable s then I
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   else Symtab.map_entry s (Integer.add 1))
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  #> fold count_term tms
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fun count_formula x = fold_formula count_term x
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val init_counters =
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  metis_helpers |> map fst |> sort_distinct string_ord |> map (rpair 0)
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  |> Symtab.make
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fun get_helper_facts ctxt explicit_forall type_sys formulas =
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  let
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    val no_dangerous_types = types_dangerous_types type_sys
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    val ct = init_counters |> fold count_formula formulas
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    fun is_used s = the (Symtab.lookup ct s) > 0
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    fun dub c needs_full_types (th, j) =
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      ((c ^ "_" ^ string_of_int j ^ (if needs_full_types then "ft" else ""),
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        false), th)
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    fun make_facts eq_as_iff = map_filter (make_fact ctxt false eq_as_iff false)
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  in
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    (metis_helpers
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     |> filter (is_used o fst)
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     |> maps (fn (c, (needs_full_types, ths)) =>
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                 if needs_full_types andalso not no_dangerous_types then
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                   []
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                 else
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                   ths ~~ (1 upto length ths)
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                   |> map (dub c needs_full_types)
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                   |> make_facts (not needs_full_types)),
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     if type_sys = Tags false then
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       let
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         fun var s = ATerm (`I s, [])
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         fun tag tm = ATerm (`I type_tag_name, [var "X", tm])
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       in
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         [Fof (helper_prefix ^ ascii_of "ti_ti", Axiom,
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               AAtom (ATerm (`I "equal", [tag (tag (var "Y")), tag (var "Y")]))
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               |> explicit_forall ? close_universally, NONE)]
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       end
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     else
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       [])
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  end
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fun translate_atp_fact ctxt keep_trivial =
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  `(make_fact ctxt keep_trivial true true)
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fun translate_formulas ctxt type_sys hyp_ts concl_t rich_facts =
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  let
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    val thy = ProofContext.theory_of ctxt
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    val fact_ts = map (prop_of o snd o snd) rich_facts
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    val (facts, fact_names) =
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   313
      rich_facts
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   314
      |> map_filter (fn (NONE, _) => NONE
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   315
                      | (SOME fact, (name, _)) => SOME (fact, name))
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   316
      |> ListPair.unzip
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   317
    (* Remove existing facts from the conjecture, as this can dramatically
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   318
       boost an ATP's performance (for some reason). *)
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   319
    val hyp_ts = hyp_ts |> filter_out (member (op aconv) fact_ts)
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   320
    val goal_t = Logic.list_implies (hyp_ts, concl_t)
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   321
    val subs = tfree_classes_of_terms [goal_t]
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   322
    val supers = tvar_classes_of_terms fact_ts
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   323
    val tycons = type_consts_of_terms thy (goal_t :: fact_ts)
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   324
    (* TFrees in the conjecture; TVars in the facts *)
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   325
    val conjs = make_conjecture ctxt (hyp_ts @ [concl_t])
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   326
    val (supers', arity_clauses) =
blanchet@41137
   327
      if type_sys = No_Types then ([], [])
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   328
      else make_arity_clauses thy tycons supers
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   329
    val class_rel_clauses = make_class_rel_clauses thy subs supers'
blanchet@38282
   330
  in
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   331
    (fact_names |> map single, (conjs, facts, class_rel_clauses, arity_clauses))
blanchet@38282
   332
  end
blanchet@38282
   333
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   334
fun tag_with_type ty t = ATerm (`I type_tag_name, [ty, t])
blanchet@38282
   335
blanchet@38282
   336
fun fo_term_for_combtyp (CombTVar name) = ATerm (name, [])
blanchet@38282
   337
  | fo_term_for_combtyp (CombTFree name) = ATerm (name, [])
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   338
  | fo_term_for_combtyp (CombType (name, tys)) =
blanchet@38282
   339
    ATerm (name, map fo_term_for_combtyp tys)
blanchet@38282
   340
blanchet@38282
   341
fun fo_literal_for_type_literal (TyLitVar (class, name)) =
blanchet@38282
   342
    (true, ATerm (class, [ATerm (name, [])]))
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   343
  | fo_literal_for_type_literal (TyLitFree (class, name)) =
blanchet@38282
   344
    (true, ATerm (class, [ATerm (name, [])]))
blanchet@38282
   345
blanchet@38282
   346
fun formula_for_fo_literal (pos, t) = AAtom t |> not pos ? mk_anot
blanchet@38282
   347
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   348
(* Finite types such as "unit", "bool", "bool * bool", and "bool => bool" are
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   349
   considered dangerous because their "exhaust" properties can easily lead to
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   350
   unsound ATP proofs. The checks below are an (unsound) approximation of
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   351
   finiteness. *)
blanchet@41138
   352
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   353
fun is_dtyp_dangerous _ (Datatype_Aux.DtTFree _) = true
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   354
  | is_dtyp_dangerous ctxt (Datatype_Aux.DtType (s, Us)) =
blanchet@41138
   355
    is_type_constr_dangerous ctxt s andalso forall (is_dtyp_dangerous ctxt) Us
blanchet@41138
   356
  | is_dtyp_dangerous _ (Datatype_Aux.DtRec _) = false
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   357
and is_type_dangerous ctxt (Type (s, Ts)) =
blanchet@41138
   358
    is_type_constr_dangerous ctxt s andalso forall (is_type_dangerous ctxt) Ts
blanchet@41140
   359
  | is_type_dangerous _ _ = false
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   360
and is_type_constr_dangerous ctxt s =
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   361
  let val thy = ProofContext.theory_of ctxt in
blanchet@41138
   362
    case Datatype_Data.get_info thy s of
blanchet@41138
   363
      SOME {descr, ...} =>
blanchet@41138
   364
      forall (fn (_, (_, _, constrs)) =>
blanchet@41138
   365
                 forall (forall (is_dtyp_dangerous ctxt) o snd) constrs) descr
blanchet@41138
   366
    | NONE =>
blanchet@41138
   367
      case Typedef.get_info ctxt s of
blanchet@41138
   368
        ({rep_type, ...}, _) :: _ => is_type_dangerous ctxt rep_type
blanchet@41138
   369
      | [] => true
blanchet@41138
   370
  end
blanchet@41138
   371
blanchet@41138
   372
fun is_combtyp_dangerous ctxt (CombType ((s, _), tys)) =
blanchet@41138
   373
    (case strip_prefix_and_unascii type_const_prefix s of
blanchet@41138
   374
       SOME s' => forall (is_combtyp_dangerous ctxt) tys andalso
blanchet@41138
   375
                  is_type_constr_dangerous ctxt (invert_const s')
blanchet@41138
   376
     | NONE => false)
blanchet@41138
   377
  | is_combtyp_dangerous _ _ = false
blanchet@41138
   378
blanchet@41138
   379
fun should_tag_with_type ctxt (Tags full_types) ty =
blanchet@41138
   380
    full_types orelse is_combtyp_dangerous ctxt ty
blanchet@41138
   381
  | should_tag_with_type _ _ _ = false
blanchet@41138
   382
blanchet@41140
   383
val fname_table =
blanchet@41140
   384
  [("c_False", (0, ("c_fFalse", @{const_name Metis.fFalse}))),
blanchet@41140
   385
   ("c_True", (0, ("c_fTrue", @{const_name Metis.fTrue}))),
blanchet@41140
   386
   ("c_Not", (1, ("c_fNot", @{const_name Metis.fNot}))),
blanchet@41140
   387
   ("c_conj", (2, ("c_fconj", @{const_name Metis.fconj}))),
blanchet@41140
   388
   ("c_disj", (2, ("c_fdisj", @{const_name Metis.fdisj}))),
blanchet@41140
   389
   ("c_implies", (2, ("c_fimplies", @{const_name Metis.fimplies}))),
blanchet@41140
   390
   ("equal", (2, ("c_fequal", @{const_name Metis.fequal})))]
blanchet@41140
   391
blanchet@41138
   392
fun fo_term_for_combterm ctxt type_sys =
blanchet@38282
   393
  let
blanchet@41138
   394
    val thy = ProofContext.theory_of ctxt
blanchet@38282
   395
    fun aux top_level u =
blanchet@38282
   396
      let
blanchet@38282
   397
        val (head, args) = strip_combterm_comb u
blanchet@38282
   398
        val (x, ty_args) =
blanchet@38282
   399
          case head of
blanchet@38282
   400
            CombConst (name as (s, s'), _, ty_args) =>
blanchet@41140
   401
            (case AList.lookup (op =) fname_table s of
blanchet@41140
   402
               SOME (n, fname) =>
blanchet@41150
   403
               (if top_level andalso length args = n then
blanchet@41150
   404
                  case s of
blanchet@41150
   405
                    "c_False" => ("$false", s')
blanchet@41150
   406
                  | "c_True" => ("$true", s')
blanchet@41150
   407
                  | _ => name
blanchet@41150
   408
                else
blanchet@41150
   409
                  fname, [])
blanchet@41140
   410
             | NONE =>
blanchet@41140
   411
               case strip_prefix_and_unascii const_prefix s of
blanchet@41140
   412
                 NONE => (name, ty_args)
blanchet@41140
   413
               | SOME s'' =>
blanchet@41140
   414
                 let
blanchet@41140
   415
                   val s'' = invert_const s''
blanchet@41140
   416
                   val ty_args =
blanchet@41140
   417
                     if needs_type_args thy type_sys s'' then ty_args else []
blanchet@41150
   418
                  in (name, ty_args) end)
blanchet@38282
   419
          | CombVar (name, _) => (name, [])
blanchet@38282
   420
          | CombApp _ => raise Fail "impossible \"CombApp\""
blanchet@41138
   421
        val t =
blanchet@41138
   422
          ATerm (x, map fo_term_for_combtyp ty_args @ map (aux false) args)
blanchet@41138
   423
        val ty = combtyp_of u
blanchet@38282
   424
    in
blanchet@41138
   425
      t |> (if should_tag_with_type ctxt type_sys ty then
blanchet@41138
   426
              tag_with_type (fo_term_for_combtyp ty)
blanchet@41134
   427
            else
blanchet@41134
   428
              I)
blanchet@38282
   429
    end
blanchet@38282
   430
  in aux true end
blanchet@38282
   431
blanchet@41138
   432
fun formula_for_combformula ctxt type_sys =
blanchet@38282
   433
  let
blanchet@38282
   434
    fun aux (AQuant (q, xs, phi)) = AQuant (q, xs, aux phi)
blanchet@38282
   435
      | aux (AConn (c, phis)) = AConn (c, map aux phis)
blanchet@41138
   436
      | aux (AAtom tm) = AAtom (fo_term_for_combterm ctxt type_sys tm)
blanchet@38282
   437
  in aux end
blanchet@38282
   438
blanchet@41138
   439
fun formula_for_fact ctxt type_sys
blanchet@40204
   440
                     ({combformula, ctypes_sorts, ...} : translated_formula) =
blanchet@38282
   441
  mk_ahorn (map (formula_for_fo_literal o fo_literal_for_type_literal)
blanchet@41137
   442
                (atp_type_literals_for_types type_sys ctypes_sorts))
blanchet@41138
   443
           (formula_for_combformula ctxt type_sys combformula)
blanchet@38282
   444
blanchet@41138
   445
fun problem_line_for_fact ctxt prefix type_sys (formula as {name, kind, ...}) =
blanchet@41769
   446
  Fof (prefix ^ ascii_of name, kind, formula_for_fact ctxt type_sys formula,
blanchet@41769
   447
       NONE)
blanchet@38282
   448
blanchet@38282
   449
fun problem_line_for_class_rel_clause (ClassRelClause {name, subclass,
blanchet@38282
   450
                                                       superclass, ...}) =
blanchet@38282
   451
  let val ty_arg = ATerm (("T", "T"), []) in
blanchet@38282
   452
    Fof (class_rel_clause_prefix ^ ascii_of name, Axiom,
blanchet@38282
   453
         AConn (AImplies, [AAtom (ATerm (subclass, [ty_arg])),
blanchet@41769
   454
                           AAtom (ATerm (superclass, [ty_arg]))]), NONE)
blanchet@38282
   455
  end
blanchet@38282
   456
blanchet@38282
   457
fun fo_literal_for_arity_literal (TConsLit (c, t, args)) =
blanchet@38282
   458
    (true, ATerm (c, [ATerm (t, map (fn arg => ATerm (arg, [])) args)]))
blanchet@38282
   459
  | fo_literal_for_arity_literal (TVarLit (c, sort)) =
blanchet@38282
   460
    (false, ATerm (c, [ATerm (sort, [])]))
blanchet@38282
   461
blanchet@38282
   462
fun problem_line_for_arity_clause (ArityClause {name, conclLit, premLits,
blanchet@38282
   463
                                                ...}) =
blanchet@38282
   464
  Fof (arity_clause_prefix ^ ascii_of name, Axiom,
blanchet@38282
   465
       mk_ahorn (map (formula_for_fo_literal o apfst not
blanchet@38282
   466
                      o fo_literal_for_arity_literal) premLits)
blanchet@38282
   467
                (formula_for_fo_literal
blanchet@41769
   468
                     (fo_literal_for_arity_literal conclLit)), NONE)
blanchet@38282
   469
blanchet@41138
   470
fun problem_line_for_conjecture ctxt type_sys
blanchet@40114
   471
        ({name, kind, combformula, ...} : translated_formula) =
blanchet@38282
   472
  Fof (conjecture_prefix ^ name, kind,
blanchet@41769
   473
       formula_for_combformula ctxt type_sys combformula, NONE)
blanchet@38282
   474
blanchet@41137
   475
fun free_type_literals_for_conjecture type_sys
blanchet@40114
   476
        ({ctypes_sorts, ...} : translated_formula) =
blanchet@41137
   477
  ctypes_sorts |> atp_type_literals_for_types type_sys
blanchet@41137
   478
               |> map fo_literal_for_type_literal
blanchet@38282
   479
blanchet@39975
   480
fun problem_line_for_free_type j lit =
blanchet@41769
   481
  Fof (tfree_prefix ^ string_of_int j, Hypothesis, formula_for_fo_literal lit,
blanchet@41769
   482
       NONE)
blanchet@41313
   483
fun problem_lines_for_free_types type_sys conjs =
blanchet@38282
   484
  let
blanchet@41313
   485
    val litss = map (free_type_literals_for_conjecture type_sys) conjs
blanchet@38282
   486
    val lits = fold (union (op =)) litss []
blanchet@39975
   487
  in map2 problem_line_for_free_type (0 upto length lits - 1) lits end
blanchet@38282
   488
blanchet@38282
   489
(** "hBOOL" and "hAPP" **)
blanchet@38282
   490
blanchet@38282
   491
type const_info = {min_arity: int, max_arity: int, sub_level: bool}
blanchet@38282
   492
blanchet@38282
   493
fun consider_term top_level (ATerm ((s, _), ts)) =
blanchet@39452
   494
  (if is_atp_variable s then
blanchet@38282
   495
     I
blanchet@38282
   496
   else
blanchet@38282
   497
     let val n = length ts in
blanchet@38282
   498
       Symtab.map_default
blanchet@38282
   499
           (s, {min_arity = n, max_arity = 0, sub_level = false})
blanchet@38282
   500
           (fn {min_arity, max_arity, sub_level} =>
blanchet@38282
   501
               {min_arity = Int.min (n, min_arity),
blanchet@38282
   502
                max_arity = Int.max (n, max_arity),
blanchet@38282
   503
                sub_level = sub_level orelse not top_level})
blanchet@38282
   504
     end)
blanchet@41138
   505
  #> fold (consider_term (top_level andalso s = type_tag_name)) ts
blanchet@38282
   506
fun consider_formula (AQuant (_, _, phi)) = consider_formula phi
blanchet@38282
   507
  | consider_formula (AConn (_, phis)) = fold consider_formula phis
blanchet@38282
   508
  | consider_formula (AAtom tm) = consider_term true tm
blanchet@38282
   509
blanchet@41769
   510
fun consider_problem_line (Fof (_, _, phi, _)) = consider_formula phi
blanchet@38282
   511
fun consider_problem problem = fold (fold consider_problem_line o snd) problem
blanchet@38282
   512
blanchet@41140
   513
(* needed for helper facts if the problem otherwise does not involve equality *)
blanchet@41140
   514
val equal_entry = ("equal", {min_arity = 2, max_arity = 2, sub_level = false})
blanchet@41140
   515
blanchet@38282
   516
fun const_table_for_problem explicit_apply problem =
blanchet@41140
   517
  if explicit_apply then
blanchet@41140
   518
    NONE
blanchet@41140
   519
  else
blanchet@41147
   520
    SOME (Symtab.empty |> Symtab.default equal_entry |> consider_problem problem)
blanchet@38282
   521
blanchet@41134
   522
fun min_arity_of thy type_sys NONE s =
blanchet@41138
   523
    (if s = "equal" orelse s = type_tag_name orelse
blanchet@38282
   524
        String.isPrefix type_const_prefix s orelse
blanchet@38282
   525
        String.isPrefix class_prefix s then
blanchet@38282
   526
       16383 (* large number *)
blanchet@38748
   527
     else case strip_prefix_and_unascii const_prefix s of
blanchet@41136
   528
       SOME s' => num_atp_type_args thy type_sys (invert_const s')
blanchet@38282
   529
     | NONE => 0)
blanchet@38282
   530
  | min_arity_of _ _ (SOME the_const_tab) s =
blanchet@38282
   531
    case Symtab.lookup the_const_tab s of
blanchet@38282
   532
      SOME ({min_arity, ...} : const_info) => min_arity
blanchet@38282
   533
    | NONE => 0
blanchet@38282
   534
blanchet@38282
   535
fun full_type_of (ATerm ((s, _), [ty, _])) =
blanchet@41138
   536
    if s = type_tag_name then SOME ty else NONE
blanchet@41138
   537
  | full_type_of _ = NONE
blanchet@38282
   538
blanchet@38282
   539
fun list_hAPP_rev _ t1 [] = t1
blanchet@38282
   540
  | list_hAPP_rev NONE t1 (t2 :: ts2) =
blanchet@38282
   541
    ATerm (`I "hAPP", [list_hAPP_rev NONE t1 ts2, t2])
blanchet@38282
   542
  | list_hAPP_rev (SOME ty) t1 (t2 :: ts2) =
blanchet@41138
   543
    case full_type_of t2 of
blanchet@41138
   544
      SOME ty2 =>
blanchet@41138
   545
      let val ty' = ATerm (`make_fixed_type_const @{type_name fun},
blanchet@41138
   546
                           [ty2, ty]) in
blanchet@41138
   547
        ATerm (`I "hAPP",
blanchet@41138
   548
               [tag_with_type ty' (list_hAPP_rev (SOME ty') t1 ts2), t2])
blanchet@41138
   549
      end
blanchet@41138
   550
    | NONE => list_hAPP_rev NONE t1 (t2 :: ts2)
blanchet@38282
   551
blanchet@41134
   552
fun repair_applications_in_term thy type_sys const_tab =
blanchet@38282
   553
  let
blanchet@38282
   554
    fun aux opt_ty (ATerm (name as (s, _), ts)) =
blanchet@41138
   555
      if s = type_tag_name then
blanchet@38282
   556
        case ts of
blanchet@38282
   557
          [t1, t2] => ATerm (name, [aux NONE t1, aux (SOME t1) t2])
blanchet@41138
   558
        | _ => raise Fail "malformed type tag"
blanchet@38282
   559
      else
blanchet@38282
   560
        let
blanchet@38282
   561
          val ts = map (aux NONE) ts
blanchet@41134
   562
          val (ts1, ts2) = chop (min_arity_of thy type_sys const_tab s) ts
blanchet@38282
   563
        in list_hAPP_rev opt_ty (ATerm (name, ts1)) (rev ts2) end
blanchet@38282
   564
  in aux NONE end
blanchet@38282
   565
blanchet@38282
   566
fun boolify t = ATerm (`I "hBOOL", [t])
blanchet@38282
   567
blanchet@38282
   568
(* True if the constant ever appears outside of the top-level position in
blanchet@38282
   569
   literals, or if it appears with different arities (e.g., because of different
blanchet@38282
   570
   type instantiations). If false, the constant always receives all of its
blanchet@38282
   571
   arguments and is used as a predicate. *)
blanchet@38282
   572
fun is_predicate NONE s =
blanchet@38589
   573
    s = "equal" orelse s = "$false" orelse s = "$true" orelse
blanchet@38589
   574
    String.isPrefix type_const_prefix s orelse String.isPrefix class_prefix s
blanchet@38282
   575
  | is_predicate (SOME the_const_tab) s =
blanchet@38282
   576
    case Symtab.lookup the_const_tab s of
blanchet@38282
   577
      SOME {min_arity, max_arity, sub_level} =>
blanchet@38282
   578
      not sub_level andalso min_arity = max_arity
blanchet@38282
   579
    | NONE => false
blanchet@38282
   580
blanchet@41140
   581
fun repair_predicates_in_term pred_const_tab (t as ATerm ((s, _), ts)) =
blanchet@41138
   582
  if s = type_tag_name then
blanchet@38282
   583
    case ts of
blanchet@38282
   584
      [_, t' as ATerm ((s', _), _)] =>
blanchet@41140
   585
      if is_predicate pred_const_tab s' then t' else boolify t
blanchet@41138
   586
    | _ => raise Fail "malformed type tag"
blanchet@38282
   587
  else
blanchet@41140
   588
    t |> not (is_predicate pred_const_tab s) ? boolify
blanchet@38282
   589
blanchet@41134
   590
fun repair_formula thy explicit_forall type_sys const_tab =
blanchet@38282
   591
  let
blanchet@41140
   592
    val pred_const_tab = case type_sys of Tags _ => NONE | _ => const_tab
blanchet@38282
   593
    fun aux (AQuant (q, xs, phi)) = AQuant (q, xs, aux phi)
blanchet@38282
   594
      | aux (AConn (c, phis)) = AConn (c, map aux phis)
blanchet@38282
   595
      | aux (AAtom tm) =
blanchet@41134
   596
        AAtom (tm |> repair_applications_in_term thy type_sys const_tab
blanchet@41140
   597
                  |> repair_predicates_in_term pred_const_tab)
blanchet@38282
   598
  in aux #> explicit_forall ? close_universally end
blanchet@38282
   599
blanchet@41134
   600
fun repair_problem_line thy explicit_forall type_sys const_tab
blanchet@41769
   601
                        (Fof (ident, kind, phi, source)) =
blanchet@41769
   602
  Fof (ident, kind, repair_formula thy explicit_forall type_sys const_tab phi,
blanchet@41769
   603
       source)
blanchet@41140
   604
fun repair_problem thy = map o apsnd o map ooo repair_problem_line thy
blanchet@38282
   605
blanchet@41140
   606
fun dest_Fof (Fof z) = z
blanchet@38282
   607
blanchet@41157
   608
val factsN = "Relevant facts"
blanchet@41157
   609
val class_relsN = "Class relationships"
blanchet@41157
   610
val aritiesN = "Arity declarations"
blanchet@41157
   611
val helpersN = "Helper facts"
blanchet@41157
   612
val conjsN = "Conjectures"
blanchet@41313
   613
val free_typesN = "Type variables"
blanchet@41157
   614
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   615
fun offset_of_heading_in_problem _ [] j = j
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   616
  | offset_of_heading_in_problem needle ((heading, lines) :: problem) j =
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   617
    if heading = needle then j
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   618
    else offset_of_heading_in_problem needle problem (j + length lines)
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   619
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   620
fun prepare_atp_problem ctxt readable_names explicit_forall type_sys
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   621
                        explicit_apply hyp_ts concl_t facts =
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   622
  let
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   623
    val thy = ProofContext.theory_of ctxt
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   624
    val (fact_names, (conjs, facts, class_rel_clauses, arity_clauses)) =
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   625
      translate_formulas ctxt type_sys hyp_ts concl_t facts
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   626
    (* Reordering these might or might not confuse the proof reconstruction
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   627
       code or the SPASS Flotter hack. *)
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   628
    val problem =
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   629
      [(factsN, map (problem_line_for_fact ctxt fact_prefix type_sys) facts),
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   630
       (class_relsN, map problem_line_for_class_rel_clause class_rel_clauses),
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   631
       (aritiesN, map problem_line_for_arity_clause arity_clauses),
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   632
       (helpersN, []),
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   633
       (conjsN, map (problem_line_for_conjecture ctxt type_sys) conjs),
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   634
       (free_typesN, problem_lines_for_free_types type_sys conjs)]
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   635
    val const_tab = const_table_for_problem explicit_apply problem
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   636
    val problem =
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   637
      problem |> repair_problem thy explicit_forall type_sys const_tab
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   638
    val helper_lines =
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   639
      get_helper_facts ctxt explicit_forall type_sys
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   640
                       (maps (map (#3 o dest_Fof) o snd) problem)
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   641
      |>> map (problem_line_for_fact ctxt helper_prefix type_sys
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   642
               #> repair_problem_line thy explicit_forall type_sys const_tab)
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   643
      |> op @
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   644
    val (problem, pool) =
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   645
      problem |> AList.update (op =) (helpersN, helper_lines)
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   646
              |> nice_atp_problem readable_names
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   647
  in
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   648
    (problem,
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   649
     case pool of SOME the_pool => snd the_pool | NONE => Symtab.empty,
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   650
     offset_of_heading_in_problem conjsN problem 0,
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   651
     fact_names |> Vector.fromList)
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   652
  end
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   653
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   654
(* FUDGE *)
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   655
val conj_weight = 0.0
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   656
val hyp_weight = 0.1
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   657
val fact_min_weight = 0.2
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   658
val fact_max_weight = 1.0
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   659
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   660
fun add_term_weights weight (ATerm (s, tms)) =
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   661
  (not (is_atp_variable s) andalso s <> "equal") ? Symtab.default (s, weight)
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   662
  #> fold (add_term_weights weight) tms
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   663
fun add_problem_line_weights weight (Fof (_, _, phi, _)) =
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   664
  fold_formula (add_term_weights weight) phi
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   665
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   666
fun add_conjectures_weights [] = I
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   667
  | add_conjectures_weights conjs =
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   668
    let val (hyps, conj) = split_last conjs in
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   669
      add_problem_line_weights conj_weight conj
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   670
      #> fold (add_problem_line_weights hyp_weight) hyps
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   671
    end
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   672
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   673
fun add_facts_weights facts =
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   674
  let
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   675
    val num_facts = length facts
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   676
    fun weight_of j =
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   677
      fact_min_weight + (fact_max_weight - fact_min_weight) * Real.fromInt j
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   678
                        / Real.fromInt num_facts
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   679
  in
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   680
    map weight_of (0 upto num_facts - 1) ~~ facts
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   681
    |> fold (uncurry add_problem_line_weights)
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   682
  end
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   683
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   684
(* Weights are from 0.0 (most important) to 1.0 (least important). *)
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   685
fun atp_problem_weights problem =
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   686
  Symtab.empty
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   687
  |> add_conjectures_weights (these (AList.lookup (op =) problem conjsN))
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   688
  |> add_facts_weights (these (AList.lookup (op =) problem factsN))
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   689
  |> Symtab.dest
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   690
  |> sort (prod_ord Real.compare string_ord o pairself swap)
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   691
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   692
end;