src/HOL/Tools/Sledgehammer/sledgehammer_atp_translate.ML

     Tags of bool |
     Args |
     Mangled |
     No_Types
 
-  val precise_overloaded_args : bool Unsynchronized.ref
+  val risky_overloaded_args : bool Unsynchronized.ref
   val fact_prefix : string
   val conjecture_prefix : string
   val is_type_system_sound : type_system -> bool
   val type_system_types_dangerous_types : type_system -> bool
   val num_atp_type_args : theory -> type_system -> string -> int

 open Metis_Translate
 open Sledgehammer_Util
 
 (* FIXME: Remove references once appropriate defaults have been determined
    empirically. *)
-val precise_overloaded_args = Unsynchronized.ref false
+val risky_overloaded_args = Unsynchronized.ref false
 
 val fact_prefix = "fact_"
 val conjecture_prefix = "conj_"
 val helper_prefix = "help_"
 val class_rel_clause_prefix = "clrel_";

    generated; if it returns "false" for an overloaded constant, the ATP gets a
    license to do unsound reasoning if the type system is "overloaded_args". *)
 fun is_overloaded thy s =
   not (s = @{const_name HOL.eq}) andalso
   not (s = @{const_name Metis.fequal}) andalso
-  (not (!precise_overloaded_args) orelse s = @{const_name finite} orelse
+  (not (!risky_overloaded_args) orelse s = @{const_name finite} orelse
    length (Defs.specifications_of (Theory.defs_of thy) s) > 1)
 
 fun needs_type_args thy type_sys s =
   case type_sys of
     Tags full_types => not full_types andalso is_overloaded thy s

     val lits = fold (union (op =)) litss []
   in map2 problem_line_for_free_type (0 upto length lits - 1) lits end
 
 (** "hBOOL" and "hAPP" **)
 
-type const_info = {min_arity: int, max_arity: int, sub_level: bool}
+type sym_info = {min_arity: int, max_arity: int, fun_sym: bool}
 
 fun consider_term top_level (ATerm ((s, _), ts)) =
   (if is_atp_variable s then
      I
    else
      let val n = length ts in
        Symtab.map_default
-           (s, {min_arity = n, max_arity = 0, sub_level = false})
-           (fn {min_arity, max_arity, sub_level} =>
+           (s, {min_arity = n, max_arity = 0, fun_sym = false})
+           (fn {min_arity, max_arity, fun_sym} =>
                {min_arity = Int.min (n, min_arity),
                 max_arity = Int.max (n, max_arity),
-                sub_level = sub_level orelse not top_level})
+                fun_sym = fun_sym orelse not top_level})
      end)
   #> fold (consider_term (top_level andalso s = type_tag_name)) ts
 fun consider_formula (AQuant (_, _, phi)) = consider_formula phi
   | consider_formula (AConn (_, phis)) = fold consider_formula phis
   | consider_formula (AAtom tm) = consider_term true tm
 
 fun consider_problem_line (Fof (_, _, phi, _)) = consider_formula phi
 fun consider_problem problem = fold (fold consider_problem_line o snd) problem
 
 (* needed for helper facts if the problem otherwise does not involve equality *)
-val equal_entry = ("equal", {min_arity = 2, max_arity = 2, sub_level = false})
-
-fun const_table_for_problem explicit_apply problem =
+val equal_entry = ("equal", {min_arity = 2, max_arity = 2, fun_sym = false})
+
+fun sym_table_for_problem explicit_apply problem =
   if explicit_apply then
     NONE
   else
     SOME (Symtab.empty |> Symtab.default equal_entry |> consider_problem problem)
 

      else case strip_prefix_and_unascii const_prefix s of
        SOME s' =>
        s' |> unmangled_const |> fst |> invert_const
           |> num_atp_type_args thy type_sys
      | NONE => 0)
-  | min_arity_of _ _ (SOME the_const_tab) s =
-    case Symtab.lookup the_const_tab s of
-      SOME ({min_arity, ...} : const_info) => min_arity
+  | min_arity_of _ _ (SOME sym_tab) s =
+    case Symtab.lookup sym_tab s of
+      SOME ({min_arity, ...} : sym_info) => min_arity
     | NONE => 0
 
 fun full_type_of (ATerm ((s, _), [ty, _])) =
     if s = type_tag_name then SOME ty else NONE
   | full_type_of _ = NONE

         ATerm (`I "hAPP",
                [tag_with_type ty' (list_hAPP_rev (SOME ty') t1 ts2), t2])
       end
     | NONE => list_hAPP_rev NONE t1 (t2 :: ts2)
 
-fun repair_applications_in_term thy type_sys const_tab =
+fun repair_applications_in_term thy type_sys sym_tab =
   let
     fun aux opt_ty (ATerm (name as (s, _), ts)) =
       if s = type_tag_name then
         case ts of
           [t1, t2] => ATerm (name, [aux NONE t1, aux (SOME t1) t2])
         | _ => raise Fail "malformed type tag"
       else
         let
           val ts = map (aux NONE) ts
-          val (ts1, ts2) = chop (min_arity_of thy type_sys const_tab s) ts
+          val (ts1, ts2) = chop (min_arity_of thy type_sys sym_tab s) ts
         in list_hAPP_rev opt_ty (ATerm (name, ts1)) (rev ts2) end
   in aux NONE end
 
 fun boolify t = ATerm (`I "hBOOL", [t])
 
 (* True if the constant ever appears outside of the top-level position in
    literals, or if it appears with different arities (e.g., because of different
    type instantiations). If false, the constant always receives all of its
    arguments and is used as a predicate. *)
-fun is_predicate NONE s =
+fun is_pred_sym NONE s =
     s = "equal" orelse s = "$false" orelse s = "$true" orelse
     String.isPrefix type_const_prefix s orelse String.isPrefix class_prefix s
-  | is_predicate (SOME the_const_tab) s =
-    case Symtab.lookup the_const_tab s of
-      SOME {min_arity, max_arity, sub_level} =>
-      not sub_level andalso min_arity = max_arity
+  | is_pred_sym (SOME sym_tab) s =
+    case Symtab.lookup sym_tab s of
+      SOME {min_arity, max_arity, fun_sym} =>
+      not fun_sym andalso min_arity = max_arity
     | NONE => false
 
-fun repair_predicates_in_term pred_const_tab (t as ATerm ((s, _), ts)) =
+fun repair_predicates_in_term pred_sym_tab (t as ATerm ((s, _), ts)) =
   if s = type_tag_name then
     case ts of
       [_, t' as ATerm ((s', _), _)] =>
-      if is_predicate pred_const_tab s' then t' else boolify t
+      if is_pred_sym pred_sym_tab s' then t' else boolify t
     | _ => raise Fail "malformed type tag"
   else
-    t |> not (is_predicate pred_const_tab s) ? boolify
-
-fun repair_formula thy explicit_forall type_sys const_tab =
-  let
-    val pred_const_tab = case type_sys of Tags _ => NONE | _ => const_tab
+    t |> not (is_pred_sym pred_sym_tab s) ? boolify
+
+fun repair_formula thy explicit_forall type_sys sym_tab =
+  let
+    val pred_sym_tab = case type_sys of Tags _ => NONE | _ => sym_tab
     fun aux (AQuant (q, xs, phi)) = AQuant (q, xs, aux phi)
       | aux (AConn (c, phis)) = AConn (c, map aux phis)
       | aux (AAtom tm) =
-        AAtom (tm |> repair_applications_in_term thy type_sys const_tab
-                  |> repair_predicates_in_term pred_const_tab)
+        AAtom (tm |> repair_applications_in_term thy type_sys sym_tab
+                  |> repair_predicates_in_term pred_sym_tab)
   in aux #> explicit_forall ? close_universally end
 
-fun repair_problem_line thy explicit_forall type_sys const_tab
+fun repair_problem_line thy explicit_forall type_sys sym_tab
                         (Fof (ident, kind, phi, source)) =
-  Fof (ident, kind, repair_formula thy explicit_forall type_sys const_tab phi,
+  Fof (ident, kind, repair_formula thy explicit_forall type_sys sym_tab phi,
        source)
 fun repair_problem thy = map o apsnd o map ooo repair_problem_line thy
 
 fun dest_Fof (Fof z) = z
 

        (class_relsN, map problem_line_for_class_rel_clause class_rel_clauses),
        (aritiesN, map problem_line_for_arity_clause arity_clauses),
        (helpersN, []),
        (conjsN, map (problem_line_for_conjecture ctxt type_sys) conjs),
        (free_typesN, problem_lines_for_free_types type_sys (facts @ conjs))]
-    val const_tab = const_table_for_problem explicit_apply problem
-    val problem =
-      problem |> repair_problem thy explicit_forall type_sys const_tab
+    val sym_tab = sym_table_for_problem explicit_apply problem
+    val problem = problem |> repair_problem thy explicit_forall type_sys sym_tab
     val helper_lines =
       get_helper_facts ctxt explicit_forall type_sys
                        (maps (map (#3 o dest_Fof) o snd) problem)
       |>> map (pair 0
                #> problem_line_for_fact ctxt helper_prefix type_sys
-               #> repair_problem_line thy explicit_forall type_sys const_tab)
+               #> repair_problem_line thy explicit_forall type_sys sym_tab)
       |> op @
     val (problem, pool) =
       problem |> AList.update (op =) (helpersN, helper_lines)
               |> nice_atp_problem readable_names
   in